渡慶次 学 (トケシ マナブ)

工学研究院 応用化学部門 分子機能化学分野教授
Last Updated :2024/12/06

■研究者基本情報

学位

  • 博士(工学), 九州大学, 1997年03月

Researchmap個人ページ

研究分野

  • ナノテク・材料, 分析化学
  • ナノテク・材料, ナノマイクロシステム
  • ナノテク・材料, ナノ材料科学

■経歴

経歴

  • 2015年06月 - 現在
    北海道大学, 大学院工学研究院 応用化学部門, 教授
  • 2014年04月 - 現在
    名古屋大学, 未来社会創造機構, 客員教授
  • 2013年12月 - 現在
    名古屋大学, 予防早期医療創成センター, 客員教授
  • 2018年01月 - 2023年01月
    西北大学, 客座教授
  • 2019年03月 - 2022年03月
    帯広畜産大学原虫病研究センター, National Research Center for Protozoan Diseases, 共同研究員
  • 2014年04月 - 2019年03月
    名古屋大学, 先端ナノバイオデバイス研究センター, 客員教授
  • 2010年04月 - 2016年03月
    愛知県「知の拠点」重点プロジェクト(兼任), 研究員
  • 2011年11月 - 2015年05月
    北海道大学 大学院工学研究院 生物機能高分子部門, 教授
  • 2011年11月 - 2014年03月
    名古屋大学 革新ナノバイオデバイス研究センター, FIRST Research Center for Innovative Nanobiodevice, 客員教授
  • 2011年09月 - 2012年02月
    カロリンスカ研究所, 客員研究員
  • 2011年01月 - 2011年10月
    名古屋大学 革新ナノバイオデバイス研究センター 1分子ナノデバイス研究部門, FIRST Research Center for Innovative Nanobiodevice, Division of Single Molecule Device Research, 部門長
  • 2005年12月 - 2011年10月
    名古屋大学大学院工学研究科化学・生物工学専攻 准教授, Graduate School of Engineering, Graduate School of Engineering
  • 2004年 - 2009年
    財団法人神奈川科学技術アカデミー, 非常勤研究員(兼任)
  • 2007年 - 2008年
    愛知県産業技術研究所 客員研究員
  • 2004年 - 2005年
    マイクロ化学技研株式会社 代表取締役
  • 2005年
    マイクロ化学技研株式会社 特別研究員(兼任)
  • 2004年
    財団法人神奈川科学技術アカデミー 研究室長
  • 1999年 - 2003年
    財団法人神奈川科学技術アカデミー 副研究室長
  • 1998年 - 1999年
    財団法人神奈川科学技術アカデミー 研究員
  • 1997年 - 1998年
    日本学術振興会 特別研究員(PD)
  • 1996年 - 1997年
    日本学術振興会 特別研究員(DC)

委員歴

  • 2021年04月 - 現在
    日本分光学会, 北海道支部支部長, 学協会
  • 2021年04月 - 現在
    日本化学会, 北海道支部幹事, 学協会
  • 2020年05月 - 現在
    化学とマイクロ・ナノシステム学会, 監事, 学協会
  • 2014年03月 - 現在
    日本分析化学会, 北海道支部幹事, 学協会
  • 2018年04月 - 2024年04月
    旭硝子財団, 研究助成選考委員, その他
  • 2020年04月 - 2024年03月
    文部科学省, 科学官, 政府
  • 2017年05月 - 2023年03月
    科学技術振興機構, 領域アドバイザー(細胞外微粒子), 政府
  • 2017年04月 - 2021年03月
    日本分析化学会, 北海道支部副支部長, 学協会
  • 2008年04月 - 2021年03月
    日本学術振興会, 未踏・ナノバイオテクノロジー第151委員会ナノバイオフュージョン分科会企画委員, 学協会
  • 2015年 - 2020年10月
    The Chemical and Biological Microsystems Society (CBMS), Director, 学協会
  • 2018年05月 - 2020年05月
    化学とマイクロ・ナノシステム学会, 会長, 学協会
  • 2010年04月 - 2020年05月
    化学とマイクロ・ナノシステム学会, 理事, 学協会
  • 2017年10月 - 2019年09月
    電気学会, C部門バイオメディカル・フォトニクス先端技術の応用に向けた協同研究委員会委員, 学協会
  • 2017年06月 - 2018年08月
    文部科学省, 科学技術・学術審議会専門委員
  • 2016年04月 - 2018年04月
    化学とマイクロ・ナノシステム学会, 副会長, 学協会
  • 2015年10月 - 2017年09月
    電気学会, C部門バイオメディカル・フォトニクス先端技術協同研究委員会委員, 学協会
  • 2013年10月 - 2015年09月
    電気学会, C部門バイオメディカル・オプティクス応用技術協同研究委員会委員, 学協会
  • 2010年04月 - 2015年03月
    日本ナノメディシン交流協会, 理事, 学協会
  • 2011年10月 - 2013年09月
    電気学会, C部門バイオメディカル・フォトニクス応用技術協同研究委員会委員, 学協会
  • 2011年01月 - 2011年10月
    名古屋大学革新ナノバイオデバイス研究センター, 運営委員, その他
  • 2009年10月 - 2011年09月
    電気学会, C部門バイオメディカル・フォトニクス応用技術調査専門委員会委員, 学協会
  • 2009年04月 - 2011年03月
    電気学会, E准部門バイオマイクロシステム技術委員会細胞マイクロシステム技術調査専門委員会委員長, 学協会
  • 2008年04月 - 2011年03月
    日本分析化学会, 中部支部常任幹事, 学協会
  • 2007年04月 - 2010年10月
    International Conference on Miniaturization Systems for Chemistry and Life Sciences (MicroTAS), Technical Program Committee Member, 学協会
  • 2008年11月 - 2010年03月
    日本化学会, 東海支部代議員, 学協会
  • 2007年 - 2009年
    International Conference on Miniaturized Systems for Chemistry and Life Sciences (µTAS), Technical Program Committee Member, その他
  • 2007年04月 - 2008年03月
    電気学会, C部門バイオメディカル・フォトニクス先端技術調査専門委員会委員, 学協会
  • 2007年04月 - 2008年03月
    日本分析化学会, 中部支部幹事, 学協会
  • 2005年12月 - 2007年11月
    電気学会, E准部門バイオマイクロシステム技術委員会バイオ極限計測マイクロシステム技術調査専門委員会幹事, 学協会
  • 2005年06月 - 2006年03月
    日本規格協会, JIS K0212改正原案作成委員会幹事, 学協会
  • 2004年03月 - 2005年11月
    日本分析化学会, 関東支部幹事, 学協会

■研究活動情報

受賞

  • 2021年10月, 物質・デバイス領域共同研究拠点, 第3回(2021年度)物質・デバイス共同研究賞               
    蛍光偏光イムノアッセイ法による抗体検出法
    渡慶次学;西山慶音;高橋和希;火原彰秀
  • 2021年02月, 北海道大学, 教育研究総長表彰               
    渡慶次学
  • 2019年04月, 英国王立化学会, フェロー               
    渡慶次 学
  • 2018年09月, 日本分析化学会, 学会賞               
    渡慶次 学
  • 2011年10月, 堀場製作所, 堀場雅夫賞               
    渡慶次 学
  • 2007年10月, Pioneers of Miniaturisation Prize               
    日本国
  • 2007年07月, 可視化情報学会学会賞(論文賞)               
    日本国
  • 2007年05月, CHEMINAS奨励賞               
    日本国

論文

  • Enhanced Broad-Spectrum Efficacy of an L2-Based mRNA Vaccine Targeting HPV Types 6, 11, 16, 18, with Cross-Protection Against Multiple Additional High-Risk Types
    Kosuke Tsukamoto, Akio Yamashita, Masatoshi Maeki, Manabu Tokeshi, Hirotatsu IMAI, Akira Fukao, Toshinobu Fujiwara, Koji Okudera, Nobuhisa Mizuki, Kenji Okuda, Masaru Shimada
    Vaccines, 2024年10月
    研究論文(学術雑誌)
  • Investigation of the Nanoparticulation Method and Cell-Killing Effect following the Mitochondrial Delivery of Hydrophobic Porphyrin-Based Photosensitizers
    Rina Naganawa, Hanjun Zhao, Yuta Takano, Masatoshi Maeki, Manabu Tokeshi, Hideyoshi Harashima, Yuma Yamada
    International Journal of Molecular Sciences, 2024年04月12日, [査読有り]
    研究論文(学術雑誌)
  • Discrimination of extracellular miRNA sources for the identification of tumor-related functions based on nanowire thermofluidics
    Kunanon Chattrairat, Akira Yokoi, Min Zhang, Mikiko Iida, Kosuke Yoshida, Masami Kitagawa, Ayuka Niwa, Masatoshi Maeki, Takeshi Hasegawa, Takeshi Yokoyama, Yoshikazu Tanaka, Yusuke Miyazaki, Wataru Shinoda, Manabu Tokeshi, Kazuki Nagashima, Takeshi Yanagida, Hiroaki Kajiyama, Yoshinobu Baba, Takao Yasui
    Device, 100363, 100363, Elsevier BV, 2024年04月
    研究論文(学術雑誌)
  • Development of Polymer-Lipid Hybrid Nanoparticles for Large-Sized Plasmid DNA Transfection.
    Masatoshi Maeki, Shuya Uno, Kaisei Sugiura, Yusuke Sato, Yoichiro Fujioka, Akihiko Ishida, Yusuke Ohba, Hideyoshi Harashima, Manabu Tokeshi
    ACS applied materials & interfaces, 16, 2, 2110, 2119, 2024年01月17日, [国際誌]
    英語, 研究論文(学術雑誌), RNA and DNA delivery technologies using lipid nanoparticles (LNPs) have advanced significantly, as demonstrated by their successful application in mRNA vaccines. To date, commercially available RNA therapeutics include Onpattro, a 21 bp siRNA, and mRNA vaccines comprising 4300 nucleotides for COVID-19. However, a significant challenge remains in achieving efficient transfection, as the size of the delivered RNA and DNA increases. In contrast to RNA transfection, plasmid DNA (pDNA) transfection requires multiple steps, including cellular uptake, endosomal escape, nuclear translocation, transcription, and translation. The low transfection efficiency of large pDNA is a critical limitation in the development of artificial cells and their cellular functionalization. Here, we introduce polymer-lipid hybrid nanoparticles designed for efficient, large-sized pDNA transfection. We demonstrated that LNPs loaded with positively charged pDNA-polycation core nanoparticles exhibited a 4-fold increase in transfection efficiency for 15 kbp pDNA compared with conventional LNPs, which encapsulate a negatively charged pDNA-polycation core. Based on assessments of the size and internal structure of the polymer-lipid nanoparticles as well as hemolysis and cellular uptake analysis, we propose a strategy to enhance large-sized pDNA transfection using LNPs. This approach holds promise for accelerating the in vivo delivery of large-sized pDNA and advancing the development of artificial cells.
  • Sensitivity-improved blocking agent-free fluorescence polarization assay through surface modification using polyethylene glycol
    Hao Liu, Mao Fukuyama, Yu Ogura, Motohiro Kasuya, Sho Onose, Ayuko Imai, Koji Shigemura, Manabu Tokeshi, Akihide Hibara
    The Analyst, Royal Society of Chemistry (RSC), 2024年
    研究論文(学術雑誌), A polyethylene glycol-based surface modification improved the sensitivity of fluorescence polarization assays in microfluidic devices, eliminating the need for blocking agents.
  • Understanding the effects of ethanol on the liposome bilayer structure using microfluidic-based time-resolved small-angle X-ray scattering and molecular dynamics simulations
    Masatoshi Maeki, Niko Kimura, Yuto Okada, Kazuki Shimizu, Kana Shibata, Yusuke Miyazaki, Akihiko Ishida, Kento Yonezawa, Nobutaka Shimizu, Wataru Shinoda, Manabu Tokeshi
    Nanoscale Advances, Royal Society of Chemistry (RSC), 2024年
    研究論文(学術雑誌), We investigated ethanol-induced structural changes in liposomes on a time scale from microseconds to tens of seconds using a microfluidic-based small-angle X-ray scattering (SAXS) measurement system coupled with molecular dynamics (MD) simulations.
  • An Ionizable Lipid Material with a Vitamin E Scaffold as an mRNA Vaccine Platform for Efficient Cytotoxic T Cell Responses
    Ryotaro Oyama, Harumichi Ishigame, Hiroki Tanaka, Naho Tateshita, Moeko Itazawa, Ryosuke Imai, Naomasa Nishiumi, Jun-ichi Kishikawa, Takayuki Kato, Jessica Anindita, Yoshifumi Nishikawa, Masatoshi Maeki, Manabu Tokeshi, Kota Tange, Yuta Nakai, Yu Sakurai, Takaharu Okada, Hidetaka Akita
    ACS Nano, American Chemical Society (ACS), 2023年09月26日
    研究論文(学術雑誌)
  • A portable liquid chromatography system based on a separation/detection chip module consisting of a replaceable ultraviolet-visible absorbance or contactless conductivity detection unit
    Akihiko Ishida, Takuma Nishimura, Kaito Koyama, Masatoshi Maeki, Hirofumi Tani, Manabu Tokeshi
    Journal of Chromatography A, 1706, 464272, 464272, Elsevier BV, 2023年09月
    研究論文(学術雑誌)
  • Rapid determination of domoic acid in seafood by fluorescence polarization immunoassay using a portable analyzer
    Yu Ogura, Mao Fukuyama, Motohiro Kasuya, Koji Shigemura, Sergei A. Eremin, Manabu Tokeshi, Akihide Hibara
    Analytical Sciences, Springer Science and Business Media LLC, 2023年08月31日
    研究論文(学術雑誌), Abstract

    Monitoring phycotoxin accumulation in marine products such as edible shellfish is a regulatory requirement in many countries. Therefore, a simple and rapid onsite quantification method is sought. Herein, we present a fluorescence polarization immunoassay (FPIA), a well-known one-step immunoassay, using a portable fluorescence polarization analyzer for domoic acid (DA), widely referred to as the primary toxin of amnesic shellfish poisoning (ASP). To establish FPIA for DA, the matrix effect of methanol, which is widely used to extract DA from shellfish, on FPIA was investigated. To validate this method, we performed a spike recovery test using oysters containing DA at a concentration equivalent to the regulatory limits of North America and the European Union (20 mg/kg). The recovery rate was found to be 79.4–114.7%, which is equivalent to that of the commercially available enzyme-linked immunosorbent assay (ELISA). We expect that this FPIA system will enable the quantitative onsite analysis of DA and significantly contribute to the safety of marine products.

    Graphical Abstract
  • Micro- and nanochamber array system for single enzyme assays.
    Kazuki Iijima, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Scientific reports, 13, 1, 13322, 13322, 2023年08月16日, [国際誌]
    英語, 研究論文(学術雑誌), Arrays of small reaction containers, ranging from 624 femtoliters (10-15 L) to 270 attoliters (10-18 L), for capturing a single enzyme molecule and measuring the activity were developed along with a new reversible sealing system based on a pneumatic valve actuator made of polydimethylsiloxane (PDMS). The valve was actuated by PBS solution, effectively preventing evaporation of the solution from the micro- and nanochambers and allowing the assay to be performed over a long period of time. The hydrolysis rates of β-D-galactosidase (β-gal), kcat, were decreased according to the decrease of the chamber size, and the overall tendency seems to be symmetrically related to the specific surface area of the chambers even under the prevented condition of non-specific adsorption. The spatial localization of the protons in the chambers, which might could affect the dissociation state of the proteins, was also investigated to explain the decrease in the hydrolysis rate. The developed chamber system developed here may be useful for artificially reproducing the confined intracellular environment and molecular crowding conditions.
  • Antigen/Adjuvant-Displaying Enveloped Viral Replica as a Self-Adjuvanting Anti-Breast-Cancer Vaccine Candidate
    Keita Ito, Hiroto Furukawa, Hiroshi Inaba, Shino Ohshima, Yoshie Kametani, Masatoshi Maeki, Manabu Tokeshi, Xuhao Huang, Kazuya Kabayama, Yoshiyuki Manabe, Koichi Fukase, Kazunori Matsuura
    Journal of the American Chemical Society, 145, 29, 15838, 15847, American Chemical Society (ACS), 2023年06月21日
    研究論文(学術雑誌)
  • Understanding the effects of ethanol on structural changes in liposomes using microfluidic-based time-resolved small-angle X-ray scattering and MD simulations
    Masatoshi Maeki, Niko Kimura, Yuto Okada, Kazuki Shimizu, Kana Shibata, Yusuke Miyazaki, Akihiko Ishida, Kento Yonezawa, Nobutaka Shimizu, Wataru Shinoda, Manabu Tokeshi
    American Chemical Society (ACS), 2023年06月09日
    Lipid nanoparticles (LNPs) are essential carrier particles in drug delivery systems, particularly in ribonucleic acid delivery. In preparing lipid-based nanoparticles, microfluidic-based ethanol injection may produce precisely size-controlled nanoparticles. Ethanol is critical in LNP formation and post-treatment processes and affects liposome size, structure, lamellarity, and drug-loading efficiency. However, the effects of time-dependent changes in the ethanol concentration on the structural dynamics of liposomes are not clearly understood. Herein, we investigated ethanol-induced structural changes in liposomes on a time scale from microseconds to tens of seconds using a microfluidic-based small-angle X-ray scattering (SAXS) measurement system coupled with molecular dynamics (MD) simulations. The time-resolved SAXS measurement system revealed that single unilamellar liposomes converted to multilamellar liposomes within 0.8 s of contact with ethanol, and the d-spacing was decreased from 6.1 (w/o ethanol) to 4.4 nm (80% ethanol) with increasing ethanol concentration. We conducted 1 µs MD simulations to understand the molecular-level structural changes in the liposomes. The MD simulations revealed that the changes in the lamellar structure caused by ethanol at the molecular level could explain the structural changes in the liposomes observed via time-resolved SAXS. Therefore, the post-treatment process to remove residual ethanol is critical in liposome formation.
  • A system that delivers an antioxidant to mitochondria for the treatment of drug-induced liver injury.
    Mitsue Hibino, Masatoshi Maeki, Manabu Tokeshi, Yoichi Ishitsuka, Hideyoshi Harashima, Yuma Yamada
    Scientific reports, 13, 1, 6961, 6961, 2023年05月10日, [国際誌]
    英語, 研究論文(学術雑誌), Mitochondria, a major source of reactive oxygen species (ROS), are intimately involved in the response to oxidative stress in the body. The production of excessive ROS affects the balance between oxidative responses and antioxidant defense mechanisms thus perturbing mitochondrial function eventually leading to tissue injury. Therefore, antioxidant therapies that target mitochondria can be used to treat such diseases and improve general health. This study reports on an attempt to establish a system for delivering an antioxidant molecule coenzyme Q10 (CoQ10) to mitochondria and the validation of its therapeutic efficacy in a model of acetaminophen (APAP) liver injury caused by oxidative stress in mitochondria. A CoQ10-MITO-Porter, a mitochondrial targeting lipid nanoparticle (LNP) containing encapsulated CoQ10, was prepared using a microfluidic device. It was essential to include polyethylene glycol (PEG) in the lipid composition of this LNP to ensure stability of the CoQ10, since it is relatively insoluble in water. Based on transmission electron microscope (TEM) observations and small angle X-ray scattering (SAXS) measurements, the CoQ10-MITO-Porter was estimated to be a 50 nm spherical particle without a regular layer structure. The use of the CoQ10-MITO-Porter improved liver function and reduced tissue injury, suggesting that it exerted a therapeutic effect on APAP liver injury.
  • Mass production system for RNA-loaded lipid nanoparticles using piling up microfluidic devices
    Masatoshi Maeki, Yuto Okada, Shuya Uno, Kaisei Sugiura, Yuichi Suzuki, Kento Okuda, Yusuke Sato, Masao Ando, Hiroyuki Yamazaki, Masaki Takeuchi, Akihiko Ishida, Hirofumi Tani, Hideyoshi Harashima, Manabu Tokeshi
    Applied Materials Today, 2023年04月, [査読有り]
    研究論文(学術雑誌)
  • Microfluidic paper-based analytical devices for cancer diagnosis
    Ahmed A. Shalaby, Chia Wen Tsao, Akihiko Ishida, Masatoshi Maeki, Manabu Tokeshi
    Sensors and Actuators B: Chemical, 379, 2023年03月15日
    研究論文(学術雑誌), Cancer is a leading cause of death worldwide. Early diagnosis of cancer is crucial for successful treatment which, in turn, will decrease mortality. The development of low-cost, accurate, and easy to operate point-of-need (PON) devices to be used for cancer diagnosis and treatment follow-up is a worldwide need, especially in developing countries. Paper-based analytical devices (PADs) are considered a key solution, as they provide a low-cost platform for developing PON biosensors for cancer biomarker detections. There are various types of 2D and 3D PADs according to the type of paper substrate (filter paper, chromatographic paper, nitrocellulose membranes, etc.), fabrication method (wax printing, screen printing, cutting, etc.), detection technique used (colorimetry, fluorescence, chemiluminescence, electrochemiluminescence, electrochemical, etc.), the assay principle and recognition element used (antibodies, aptamers, DNA, nanoparticles, enzymes, etc.). Controlling all these factors determines the performance, accuracy, and sensitivity of the developed devices. This review discusses all these factors in the different PADs used for detection of cancer biomarkers and summarizes the advantages and disadvantages of each one.
  • Effects of Addition of Blocking Agents on Fluorescence Polarization Immunoassay of Okadaic Acid Using a Microfluidic Device
    Shunsuke CHIDA, Kazuki TAKAHASHI, Mao FUKUYAMA, Motohiro KASUYA, Masatoshi MAEKI, Akihiko ISHIDA, Hirofumi TANI, Koji SHIGEMURA, Anatoly V. ZHERDEV, Sergei A. EREMIN, Akihide HIBARA, Manabu TOKESHI
    BUNSEKI KAGAKU, 72, 3, 133, 138, Japan Society for Analytical Chemistry, 2023年03月05日, [査読有り]
    日本語, 研究論文(学術雑誌)
  • ポータブル小型液体クロマトグラフ用の深紫外発光ダイオードを用いた吸光度検出モジュールの開発 ポータブル液体クロマト小型グラフのための深紫外発光漸ベースの吸光度検出モジュールの開発
    Kaito Koyama, Takuma Nishimura, Akihiko Ishida, Mitsue Hibino, Masatoshi Maeki, Hirofumi Tani, Manabu Tokeshi
    分析化学, 72, 3, 125, 131, 2023年03月
    日本語, 研究論文(学術雑誌)
  • Structure of lasso peptide epimerase MslH reveals metal-dependent acid/base catalytic mechanism
    Yu Nakashima, Atsushi Kawakami, Yasushi Ogasawara, Masatoshi Maeki, Manabu Tokeshi, Tohru Dairi, Hiroyuki Morita
    2023年01月12日
  • Construction of the systemic anticancer immune environment in tumour-bearing humanized mouse by using liposome-encapsulated anti-programmed death ligand 1 antibody-conjugated progesterone
    Yoshie Kametani, Ryoji Ito, Shino Ohshima, Yoshiyuki Manabe, Yusuke Ohno, Tomoka Shimizu, Soga Yamada, Nagi Katano, Daiki Kirigaya, Keita Ito, Takuya Matsumoto, Banri Tsuda, Hirofumi Kashiwagi, Yumiko Goto, Atsushi Yasuda, Masatoshi Maeki, Manabu Tokeshi, Toshiro Seki, Koichi Fukase, Mikio Mikami, Kiyoshi Ando, Hitoshi Ishimoto, Takashi Shiina
    Frontiers in Immunology, 14, 2023年
    研究論文(学術雑誌), Immune checkpoint inhibitors highlight the importance of anticancer immunity. However, their clinical utility and safety are limited by the low response rates and adverse effects. We focused on progesterone (P4), a hormone produced by the placenta during pregnancy, because it has multiple biological activities related to anticancer and immune regulation effects. P4 has a reversible immune regulatory function distinct from that of the stress hormone cortisol, which may drive irreversible immune suppression that promotes T cell exhaustion and apoptosis in patients with cancer. Because the anticancer effect of P4 is induced at higher than physiological concentrations, we aimed to develop a new anticancer drug by encapsulating P4 in liposomes. In this study, we prepared liposome-encapsulated anti-programmed death ligand 1 (PD-L1) antibody-conjugated P4 (Lipo-anti-PD-L1-P4) and evaluated the effects on the growth of MDA-MB-231 cells, a PD-L1-expressing triple-negative breast cancer cell line, in vitro and in NOG-hIL-4-Tg mice transplanted with human peripheral blood mononuclear cells (humanized mice). Lipo-anti-PD-L1-P4 at physiological concentrations reduced T cell exhaustion and proliferation of MDA-MB-231 in vitro. Humanized mice bearing MDA-MB-231 cells expressing PD-L1 showed suppressed tumor growth and peripheral tissue inflammation. The proportion of B cells and CD4+ T cells decreased, whereas the proportion of CD8+ T cells increased in Lipo-anti-PD-L1-P4-administrated mice spleens and tumor-infiltrated lymphocytes. Our results suggested that Lipo-anti-PD-L1-P4 establishes a systemic anticancer immune environment with minimal toxicity. Thus, the use of P4 as an anticancer drug may represent a new strategy for cancer treatment.
  • Controlling lamellarity and physicochemical properties of liposomes prepared using a microfluidic device
    Yuka Matsuura-Sawada, Masatoshi Maeki, Shuya Uno, Koichi Wada, Manabu Tokeshi
    Biomaterials Science, 2023年
    研究論文(学術雑誌), The function of liposomal drugs and cosmetics is not only controlled by the lipid composition/formulation, but also by the liposome size and internal structure/properties (uni- and multi-lamellae) and membrane rigid/fluidic properties. Although the preparation of liposomes using microfluidic devices offers precise size control and easy scale-up in a continuous manufacturing system, their lamellarity and physicochemical property differences have not been investigated. We therefore prepared different paclitaxel (PTX)-loaded liposomes by changing two process parameters and investigated their physicochemical properties. The liposome size and drug loading were modified by changing the initial lipid concentration and flow rate ratio (FRR) of the aqueous and ethanol phases introduced into the microfluidic channels. Small-angle X-ray scattering and transmission electron microscopy revealed that the liposomes comprised a uni- or multi-lamellar structure that could be controlled by changing the FRR and initial lipid concentration. We also found that these structural differences affected the drug release profiles. Furthermore, the dissolution kinetics of the latter half of the drug release test could be modulated by the membrane fluidity of the liposomes. These differences in the drug release rates were consistent with the results of the in vitro cell viability assay, confirming that the multilamellar liposomes showed milder activity than the PTX solution by allowing the extended release of PTX. Thus, we concluded that the preparation of liposomes using microfluidic devices allows the liposome size, DL%, and drug release profiles to be adjusted as required.
  • Microfluidic Platform Enabling Efficient On-Device Preparation of Lipid Nanoparticles for Formulation Screening
    Yuka Matsuura-Sawada, Shuya Uno, Masatoshi Maeki, Koichi Wada, Manabu Tokeshi
    ACS Applied Engineering Materials, 2022年11月10日
    研究論文(学術雑誌)
  • Effect of Organic Solvents on a Production of PLGA-Based Drug-Loaded Nanoparticles Using a Microfluidic Device
    Yi Bao, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    ACS Omega, 7, 37, 33079, 33086, 2022年09月20日, [査読有り]
    研究論文(学術雑誌), The translation of nanoparticles (NPs) from laboratory to clinical settings is limited, which is not ideal. One of the reasons for this is that we currently have limited ability to precisely regulate various physicochemical parameters of nanoparticles. This has made it difficult to rapidly perform targeted screening of drug preparation conditions. In this study, we attempted to broaden the range of preparation conditions for particle size-modulated poly(lactic-co-glycolic-acid) (PLGA) NP to enhance their applicability for drug delivery systems (DDS). This was done using a variety of organic solvents and a glass-based microfluidic device. Furthermore, we compared the PDMS-based microfluidic device to the glass-based microfluidic device in terms of the possibility of a wider range of preparation conditions, especially the effect of different solvents on the size of the PLGA NPs. PLGA NPs with different sizes (sub-200 nm) were successfully prepared, and three different types of taxanes were employed for encapsulation. The drug-loaded NPs showed size-dependent cytotoxicity in cellular assays, regardless of the taxane drug used.
  • Fine-tuning the encapsulation of a photosensitizer in nanoparticles reveals the relationship between internal structure and phototherapeutic effects.
    Fumika Kubota, Satrialdi, Yuta Takano, Masatoshi Maeki, Manabu Tokeshi, Hideyoshi Harashima, Yuma Yamada
    Journal of biophotonics, 16, 3, e202200119, 2022年09月01日, [国際誌]
    英語, 研究論文(学術雑誌), Photodynamic therapy (PDT) is a cancer therapy that uses a photosensitizer (PS) in the presence of oxygen molecules. Since singlet oxygen is highly reactive, it is important to deliver it to the target site. Thus, an efficient drug delivery system (DDS) is essential for enhancing the efficacy of such a treatment and protecting against the side effects of PDT. Here, we report on attempts to increase the therapeutic effect of PDT by using a DDS, a lipid nanoparticle (LNP). We prepared a porphyrin analog, rTPA (PS) that was encapsulated in LNPs using a microfluidic device. The findings indicated that the internal structure of the prepared particles changed depending on the amount of rTPA in LNPs. The photoactivity and cell-killing effect of PS in LNPs also changed when the amount of the cargo increased. These results suggest that the internal structure of LNPs is important factors that affect drug efficacy. This article is protected by copyright. All rights reserved.
  • Preparation of size-tunable sub-200 nm PLGA-based nanoparticles with a wide size range using a microfluidic platform
    Yi Bao, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    PLOS ONE, 17, 8, PUBLIC LIBRARY SCIENCE, 2022年08月
    英語, 研究論文(学術雑誌), The realization of poly (lactic-co-glycolic acid) nanoparticles (PLGA NPs) from laboratory to clinical applications remains slow, partly because of the lack of precise control of each condition in the preparation process and the rich selectivity of nanoparticles with diverse characteristics. Employing PLGA NPs to establish a large range of size-controlled drug delivery systems and achieve size-selective drug delivery targeting remains a challenge for therapeutic development for different diseases. In this study, we employed a microfluidic device to control the size of PLGA NPs. PLGA, poly (ethylene glycol)-methyl ether block poly (lactic-co-glycolide) (PEG-PLGA), and blend (PLGA + PEG-PLGA) NPs were engineered with defined sizes. Blend NPs exhibit the widest size range (40-114 nm) by simply changing the flow rate conditions without changing the precursor (polymer molecular weight, concentration, and chain segment composition). A model hydrophobic drug, paclitaxel (PTX), was encapsulated in the NPs, and the PTX-loaded NPs maintained a large range of controllable NP sizes. Furthermore, size-controlled NPs were used to investigate the effect of particle size of sub-200 nm NPs on tumor cell growth. The 52 nm NPs showed higher cell growth inhibition than 109 nm NPs. Our method allows the preparation of biodegradable NPs with a large size range without changing polymer precursors as well as the nondemanding fluid conditions. In addition, our model can be applied to elucidate the role of particle sizes of sub-200 nm particles in various biomedical applications, which may help develop suitable drugs for different diseases.
  • On the size-regulation of RNA-loaded lipid nanoparticles synthesized by microfluidic device.
    Kento Okuda, Yusuke Sato, Kazuki Iwakawa, Kosuke Sasaki, Nana Okabe, Masatoshi Maeki, Manabu Tokeshi, Hideyoshi Harashima
    Journal of controlled release : official journal of the Controlled Release Society, 348, 648, 659, 2022年06月18日, [国際誌]
    英語, 研究論文(学術雑誌), The use of lipid nanoparticles (LNPs) for nucleic acid delivery is now becoming a promising strategy with a number of clinical trials as vaccines or as novel therapies against a variety of genetic and infectious diseases. The use of microfluidics for the synthesis of the LNPs has attracted interest because of its considerable advantages over other conventional synthetic methods including scalability, reproducibility, and speed. However, despite the potential usefulness of large particles for nucleic acid delivery to dendritic cells (DCs) as a vaccine, the particle size of the LNPs prepared using microfluidics is typically limited to approximately from 30 to 100 nm. In this study, focusing on Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, the effect of some synthetic parameters, including total flow rate, flow rate ratio, buffer pH, lipid concentration, molar ratio of PEG-lipid as well as salt concentration, on particle size was systematically examined by means of the design of experiment approaches. The findings indicated that the simple addition of salt (e.g. NaCl) to a buffer containing nucleic acids contributed greatly to the synthesis of large LNPs over 200 nm and this effect was concentration-dependent with respect to the salt. The effect of salt on particle size was consistent with a Hofmeister series. The systemic injection of larger mRNA-loaded LNPs resulted in a higher transgene expression in mouse splenic DCs, a higher activation of various splenic immune cells, and had a superior effect as a therapeutic cancer vaccine in a syngeneic mouse model compared to the smaller-sized counterpart with constant lipid composition prepared with lower NaCl concentration. Collectively, size-regulation by the simple addition of salt is a promising strategy for developing potent LNPs.
  • Non-competitive fluorescence polarization immunosensing for CD9 detection using a peptide as a tracer.
    Kazuki Takahashi, Shunsuke Chida, Thanawat Suwatthanarak, Mikiko Iida, Min Zhang, Mao Fukuyama, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Takao Yasui, Yoshinobu Baba, Akihide Hibara, Mina Okochi, Manabu Tokeshi
    Lab on a chip, 22, 16, 2971, 2977, 2022年06月17日, [国際誌]
    英語, 研究論文(学術雑誌), This paper is the first report of a non-competitive fluorescence polarization immunoassay (NC-FPIA) using a peptide as a tracer. The NC-FPIA can easily and quickly quantify the target after simply mixing them together. This feature is desirable for point-of-need applications such as clinical diagnostics, infectious disease screening, on-site analysis for food safety, etc. In this study, the NC-FPIA was applied to detect CD9, which is one of the exosome markers. We succeeded in detecting not only CD9 but also CD9 expressing exosomes derived from HeLa cells. This method can be applied to various targets if a tracer for the target can be prepared, and expectations are high for its future uses.
  • ミトコンドリア活性化ヒト由来心筋幹細胞を用いた細胞移植療法の検証               
    白石 真大, 山田 勇磨, 佐々木 大輔, 日比野 光恵, 真栄城 正寿, 渡慶次 学, 武田 充人, 原島 秀吉
    日本DDS学会学術集会プログラム予稿集, 38回, 115, 115, 日本DDS学会, 2022年06月
    日本語
  • Microfluidic technologies and devices for lipid nanoparticle-based RNA delivery
    Masatoshi Maeki, Shuya Uno, Ayuka Niwa, Yuto Okada, Manabu Tokeshi
    Journal of Controlled Release, 344, 80, 96, 2022年04月
    研究論文(学術雑誌), In 2021, mRNA vaccines against COVID-19 were approved by the Food and Drug Administration. mRNA vaccines are important for preventing severe COVID-19 and returning to normal life. The development of RNA-delivery technology, including mRNA vaccines, has been investigated worldwide for ~30 years. Lipid nanoparticles (LNPs) are a breakthrough technology that stably delivers RNA to target organs, and RNA-loaded LNP-based nanomedicines have been studied for the development of vaccines and nanomedicines for RNA-, gene-, and cell-based therapies. Recently, microfluidic devices and technologies have attracted attention for the production of LNPs, particularly RNA-loaded LNPs. Microfluidics provides many advantages for RNA-loaded LNP production, including precise LNP size controllability, high reproducibility, high-throughput optimization of LNP formulation, and continuous LNP-production processes. In this review, we summarize microfluidic-based RNA-loaded LNP production and its applications in RNA-based therapy and genome editing.
  • Microfluidic technologies and devices for lipid nanoparticle-based RNA delivery.
    Masatoshi Maeki, Shuya Uno, Ayuka Niwa, Yuto Okada, Manabu Tokeshi
    Journal of controlled release : official journal of the Controlled Release Society, 344, 80, 96, 2022年04月, [国際誌]
    英語, 研究論文(学術雑誌), In 2021, mRNA vaccines against COVID-19 were approved by the Food and Drug Administration. mRNA vaccines are important for preventing severe COVID-19 and returning to normal life. The development of RNA-delivery technology, including mRNA vaccines, has been investigated worldwide for ~30 years. Lipid nanoparticles (LNPs) are a breakthrough technology that stably delivers RNA to target organs, and RNA-loaded LNP-based nanomedicines have been studied for the development of vaccines and nanomedicines for RNA-, gene-, and cell-based therapies. Recently, microfluidic devices and technologies have attracted attention for the production of LNPs, particularly RNA-loaded LNPs. Microfluidics provides many advantages for RNA-loaded LNP production, including precise LNP size controllability, high reproducibility, high-throughput optimization of LNP formulation, and continuous LNP-production processes. In this review, we summarize microfluidic-based RNA-loaded LNP production and its applications in RNA-based therapy and genome editing.
  • Enzyme kinetics in confined geometries at the single enzyme level.
    Hisashi Murahara, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    The Analyst, 147, 7, 1375, 1384, 2022年03月28日, [国際誌]
    英語, 研究論文(学術雑誌), The effects of increased confinement on the catalytic rates of individual enzyme molecules were studied at the single molecule level using femtolitre chambers and molecular crowders. According to the increase of confinement, from micro to nanometer cubic space in the chambers, the hydrolysis rate of β-galactosidase (β-gal) decreased to one-tenth of the rate in bulk. When molecular crowders suppressed the diffusion rates that reduced the collision chance of an enzyme and a substrate, the hydrolysis rate also decreased, which happened also in the case of femtolitre chambers. However, their kinetic trend was different especially from the viewpoint of the diffusion rates in diffusion-limited space. These data suggested that cell or organelle-scale confined environments might affect the kinetics of biochemical reactions and emphasized the importance of understanding enzyme kinetics in the in vivo environment.
  • Production of siRNA-Loaded Lipid Nanoparticles using a Microfluidic Device.
    Masatoshi Maeki, Yuto Okada, Shuya Uno, Ayuka Niwa, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Journal of visualized experiments : JoVE, 181, 2022年03月22日, [国際誌]
    英語, 研究論文(学術雑誌), The development of functional lipid nanoparticles (LNPs) is one of the major challenges in the field of drug delivery systems (DDS). Recently, LNP-based RNA delivery systems, namely, RNA-loaded LNPs have attracted attention for RNA therapy. In particular, mRNA-loaded LNP vaccines were approved to prevent COVID-19, thereby leading to the paradigm shift toward the development of next-generation nanomedicines. For the LNP-based nanomedicines, the LNP size is a significant factor in controlling the LNP biodistribution and LNP performance. Therefore, a precise LNP size control technique is indispensable for the LNP production process. Here, we report a protocol for size controlled LNP production using a microfluidic device, named iLiNP. siRNA loaded LNPs are also produced using the iLiNP device and evaluated by in vitro experiment. Representative results are shown for the LNP size, including siRNA-loaded LNPs, Z-potential, siRNA encapsulation efficiency, cytotoxicity, and target gene silencing activity.
  • Dimethoxytriadinylation LC-MS/MS of Novichok A-Series Degradation Products in Human Urine.
    Akinori Yamaguchi, Hajime Miyaguchi, Manabu Tokeshi
    Analytical chemistry, 94, 11, 4658, 4665, 2022年03月22日, [国際誌]
    英語, 研究論文(学術雑誌), Novichok A-series compounds, novel nerve agents, pose an increasing threat to citizens worldwide; however, no analytical methods have been reported for detecting their hydrolysis products. Herein, a screening method was developed to detect and identify Novichok A-series degradation products (hydrolysates of A230, A232, A234, A262, and one related compound) and alkyl methylphosphonic acids (RMPAs, conventional nerve agent hydrolysates) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). We identified a suitable derivatization reagent, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM), and optimized the reaction conditions. The derivatized esters of Novichok A-series degradation products were stable and easily detected. We used this derivatization to achieve the first analytical method for Novichok hydrolysis products in urine (0.40-4.0 ng/mL). The detection limits of the RMPAs (0.1-0.4 ng/mL) were comparable to those presented in previous reports involving pentafluorobenzylation or direct LC-MS/MS. The applicability of the newly developed method was evaluated by analyzing urine samples from the OPCW Fifth Biomedical Proficiency Test.
  • ミトコンドリア標的型DDSによるミトコンドリア病治療戦略の検証               
    荒井 愛永, 山田 勇磨, 佐々木 大輔, 真栄城 正寿, 渡慶次 学, 原島 秀吉
    日本薬学会年会要旨集, 142年会, 27I, am02S, (公社)日本薬学会, 2022年03月
    日本語
  • Production of siRNA-Loaded Lipid Nanoparticles using a Microfluidic Device
    Masatoshi Maeki, Yuto Okada, Shuya Uno, Ayuka Niwa, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Journal of Visualized Experiments, 2022, 181, 2022年03月
    研究論文(学術雑誌), The development of functional lipid nanoparticles (LNPs) is one of the major challenges in the field of drug delivery systems (DDS). Recently, LNP-based RNA delivery systems, namely, RNA-loaded LNPs have attracted attention for RNA therapy. In particular, mRNA-loaded LNP vaccines were approved to prevent COVID-19, thereby leading to the paradigm shift toward the development of next-generation nanomedicines. For the LNP-based nanomedicines, the LNP size is a significant factor in controlling the LNP biodistribution and LNP performance. Therefore, a precise LNP size control technique is indispensable for the LNP production process. Here, we report a protocol for size controlled LNP production using a microfluidic device, named iLiNP. siRNA loaded LNPs are also produced using the iLiNP device and evaluated by in vitro experiment. Representative results are shown for the LNP size, including siRNA-loaded LNPs, Z-potential, siRNA encapsulation efficiency, cytotoxicity, and target gene silencing activity.
  • Bioanalytical Technologies for Safety Control of Fish and Seafood by Sensitive Rapid Tests for Phycotoxins
    S A Eremin, A V Zherdev, M Tokeshi, A Hibara
    IOP Conference Series: Earth and Environmental Science, 988, 4, 042041, 042041, IOP Publishing, 2022年02月01日
    研究論文(学術雑誌), Abstract

    Wide and operate safety monitoring of foodstuffs is highly demanded in modern society. This work aims to develop and characterize new test systems for control of phycotoxins, dangerous contaminants of fish and seafood. For rapid and productive testing, 2 methods have been implemented: immunochromatographic assay and fluorescence polarization immunoassay. Various approaches for reducing the limit of detection of target analytes have been considered, including changes in the use of optical and fluorescent labels and varied order of the detected complexes formation. Antibodies and aptamers have been considered as receptor molecules. The developed techniques provide rapid (20–30 minutes, including sample preparation) and sensitive testing. Their effectiveness has been shown for different kinds of fish and seafood. Portable detectors have been proposed that allow testing directly at the sampling points, without transportation to centralized laboratories.
  • Microfluidic Device-Enabled Mass Production of Lipid-Based Nanoparticles for Applications in Nanomedicine and Cosmetics
    Yuka Matsuura-Sawada, Masatoshi Maeki, Takaaki Nishioka, Ayuka Niwa, Jun Yamauchi, Masashi Mizoguchi, Koichi Wada, Manabu Tokeshi
    ACS Applied Nano Materials, 5, 6, 7867, 7876, 2022年
    研究論文(学術雑誌), The preparation of lipid-based nanoparticles (LNPs) using microfluidic devices offers significant advantages, such as precise size control and easy scale-up, in a continuous manufacturing system. However, improvements in this preparation method are needed to enhance LNP productivity to meet commercial, such as clinical and consumer, demands. Feeding a highly concentrated lipid solution into microfluidic devices to obtain a high concentration of LNPs is one of the ways to boost productivity. However, this has not been investigated in detail because a high concentration of lipids in ethanol makes it difficult to control the size and dispersity of LNPs. We previously developed iLiNP, a microfluidic device with simple baffle mixer structures, which can achieve rapid ethanol dilution. The applicability of iLiNP for producing LNPs by feeding a highly concentrated lipid solution has not been investigated. Herein, we demonstrate the preparation of monodispersed LNPs using a highly concentrated lipid solution. We compare the performance of iLiNP with those of three commercially available microfluidic devices. The area of the aqueous-ethanol interface and the dilution rate of ethanol significantly affects the size controllability and dispersity of LNPs at high lipid concentrations. Compared with other microfluidic devices, iLiNP could produce smaller and more concentrated (particles/mL) LNPs. We show that by controlling the LNP size using microfluidic devices, especially iLiNP, it is possible to feed highly concentrated lipid solutions. This feature of iLiNP could be a time- and cost-saving option for the mass production of LNPs for application in nanomedicine and cosmetics.
  • Determination of blood lithium-ion concentration using digital microfluidic whole-blood separation and preloaded paper sensors
    Takeshi Komatsu, Manabu Tokeshi, Shih-Kang Fan
    Biosensors and Bioelectronics, 195, 113631, 113631, Elsevier BV, 2022年01月, [査読有り], [責任著者]
    英語, 研究論文(学術雑誌)
  • Topology-Dependent Interaction of Cyclic Poly(ethylene glycol) Complexed with Gold Nanoparticles against Bovine Serum Albumin for a Colorimetric Change
    Onyinyechukwu Justina Oziri, Masatoshi Maeki, Manabu Tokeshi, Takuya Isono, Kenji Tajima, Toshifumi Satoh, Shin-ichiro Sato, Takuya Yamamoto
    Langmuir, 38, 17, 5286, 5295, American Chemical Society (ACS), 2021年12月08日
    研究論文(学術雑誌)
  • Electrochemical enzyme-based blood ATP and lactate sensor for a rapid and straightforward evaluation of illness severity
    Keine Nishiyama, Ryohei Mizukami, Shizuka Kuki, Akihiko Ishida, Junji Chida, Hiroshi Kido, Masatoshi Maeki, Hirofumi Tani, Manabu Tokeshi
    Biosensors and Bioelectronics, 113832, 113832, Elsevier BV, 2021年11月
    研究論文(学術雑誌)
  • Microchip immunoassays for monitoring renal function: Rapid, low‐cost, and highly sensitive quantification of urinary biomarkers of diabetic nephropathy
    Toshihiro Kasama, Miaomiao Sun, Noritada Kaji, Shin’Ichi Akiyama, Yukio Yuzawa, Manabu Tokeshi, Seiichi Matsuo, Yoshinobu Baba
    Micromachines, 12, 11, 2021年11月
    研究論文(学術雑誌), This study developed low‐cost and highly sensitive immunoassay devices possessing the ability to rapidly analyze urine samples. Further, they can quantitatively detect three biomarkers indicating renal injury: monocyte chemotactic protein 1 (MCP‐1), angiotensinogen (AGT), and liver-type fatty acid binding protein (L‐FABP). The devices were used to successfully estimate the concentrations of the three biomarkers in urine samples within 2 min; the results were consistent with those obtained via conventional enzyme‐linked immunosorbent assay (ELISA), which requires several hours. In addition, the estimated detection limits for the three biomarkers were comparable to those of commercially available ELISA kits. Thus, the proposed and fabricated devices facilitate high‐precision and frequent monitoring of renal function.
  • Determination of Deoxynivalenol in Wheat, Barley, Corn Meal, and Wheat-Based Products by Simultaneous Multisample Fluorescence Polarization Immunoassay Using a Portable Analyzer
    Ayano Nakamura, Mitsutoshi Aoyagi, Mao Fukuyama, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Koji Shigemura, Akihide Hibara, Manabu Tokeshi
    ACS Food Science & Technology, 1, 9, 1623, 1628, American Chemical Society (ACS), 2021年10月15日, [査読有り], [最終著者, 責任著者]
    英語, 研究論文(学術雑誌), With globalization, importing and exporting of agricultural products and foods have expanded, and food safety has become an important issue worldwide. Mycotoxin contamination of agricultural products and foods (processed foods) can occur anywhere, and it is desirable to develop a technology that can detect mycotoxin levels easily and quickly. By using a portable analyzer that can measure multiple samples simultaneously by combining a microfluidic device and a fluorescence polarization measurement system (a portable FP analyzer), we have successfully measured deoxynivalenol (DON), which is a common mycotoxin, easily and quickly by fluorescence polarized immunoassay (FPIA). The recovery rates of DON spiked in wheat, barley, cornmeal, flour, bread, pasta, thick wheat noodles (udon), and thin wheat noodles (somen) were between 86.3 and 113.2%, and the coefficient of variation was less than 8.5%. These FPIA results were in good agreement with results obtained by the official government-recognized method of liquid chromatography-mass spectrometry for DON analysis. The FP portable analyzer has great potential as an analytical tool that contributes to food safety.
  • Facile and rapid detection of SARS-CoV-2 antibody based on a noncompetitive fluorescence polarization immunoassay in human serum samples
    Keine Nishiyama, Kazuki Takahashi, Mao Fukuyama, Motohiro Kasuya, Ayuko Imai, Takumi Usukura, Nako Maishi, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Kyoko Hida, Koji Shigemura, Akihide Hibara, Manabu Tokeshi
    Biosensors and Bioelectronics, 190, 113414, 113414, Elsevier BV, 2021年10月, [査読有り], [最終著者, 責任著者]
    英語, 研究論文(学術雑誌), Antibody detection methods for viral infections have received broad attention due to the COVID-19 pandemic. In addition, there remains an ever-increasing need to quantitatively evaluate the immune response to develop vaccines and treatments for COVID-19. Here, we report an analytical method for the rapid and quantitative detection of SARS-CoV-2 antibody in human serum by fluorescence polarization immunoassay (FPIA). A recombinant SARS-CoV-2 receptor binding domain (RBD) protein labeled with HiLyte Fluor 647 (F-RBD) was prepared and used for FPIA. When the anti-RBD antibody in human serum binds to F-RBD, the degree of polarization (P) increases by suppressing the rotational diffusion of F-RBD. The measurement procedure required only mixing a reagent containing F-RBD with serum sample and measuring the P value with a portable fluorescence polarization analyzer after 15 min incubation. We evaluated analytical performance of the developed FPIA system using 30 samples: 20 COVID-19 positive sera and 10 negative sera. The receiver operating characteristic curve drawn with the obtained results showed that this FPIA system had high accuracy for discriminating COVID-19 positive or negative serum (AUC = 0.965). The total measurement time was about 20 min, and the serum volume required for measurement was 0.25 μL. Therefore, we successfully developed the FPIA system that enables rapid and easy quantification of SARS-CoV-2 antibody. It is believed that our FPIA system will facilitate rapid on-site identification of infected persons and deepen understanding of the immune response to COVID-19.
  • Using a Paper-Based Analytical Device Designed for Remote Learning Environments to Achieve Simple Quantitative Colorimetry without Micropipettes
    Takeshi Komatsu, Ryan Russel Gabatino, Harrienica Hofileña, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Journal of Chemical Education, 98, 9, 3050, 3054, American Chemical Society (ACS), 2021年09月14日, [査読有り], [最終著者, 責任著者]
    英語, 研究論文(学術雑誌), The majority of chemical experiments conducted during educational programs are carried out in laboratories because they require instructors with special skills, in addition to large, expensive instruments. Recently, there has been an increasing demand for chemical experiments that can be carried out anywhere. Herein, we propose a novel type of paper-based analytical device (PAD) for enabling quantitative analysis without the requirement for a micropipette, since the PAD features a large sample loading zone and a waste zone, enabling accurate volume control of a liquid sample. We initially employed a micropipette to evaluate the PAD and demonstrate the quantitative analysis of ascorbic acid (AA) and pH using different loading volumes. Finally, we determined the AA concentrations and pH values of commercially available beverages using disposable plastic droppers, and the obtained results were in good agreement with those obtained through conventional methods. This PAD format can therefore be used as a novel educational tool for conducting certain chemical analyses in remote learning environments.
  • Paper-Based Analytical Device for the On-Site Detection of Nerve Agents
    Akinori Yamaguchi, Hajime Miyaguchi, Akihiko Ishida, Manabu Tokeshi
    ACS Applied Bio Materials, 4, 8, 6512, 6518, American Chemical Society (ACS), 2021年08月16日, [査読有り], [最終著者, 責任著者], [国際誌]
    英語, 研究論文(学術雑誌), We report a colorimetric paper-based microfluidic device based on an enzyme inhibition assay that allows the on-site detection of nerve agents by sampling and wicking. The sample and reagents are automatically transported through the channel where an enzyme inhibition reaction is conducted, followed by an enzyme-substrate reaction and a color reaction. This device can detect 0.1 μg/mL of the nerve agent VX in a 2.5 μL drop and is nerve agent selective and robust against temperature, pH, and several liquids. We confirmed that sampling procedures (dilution and wiping) are applicable to this device. Furthermore, the fabrication procedure is easy, and the cost is at most a few tens of cents. Thus, the present device provides a practical method for the urgent detection of nerve agents in suspected chemical terrorism incidents.
  • ミトコンドリア人工共生による細胞機能制御の試み               
    山田 勇磨, 日比野 光恵, 伊藤 百, 荒井 愛永, 佐々木 大輔, 真栄城 正寿, 渡慶次 学, 太田 善浩, 原島 秀吉
    日本DDS学会学術集会プログラム予稿集, 37回, 111, 111, 日本DDS学会, 2021年06月
    日本語
  • ミトコンドリア人工共生による細胞機能制御の試み               
    山田 勇磨, 日比野 光恵, 伊藤 百, 荒井 愛永, 佐々木 大輔, 真栄城 正寿, 渡慶次 学, 太田 善浩, 原島 秀吉
    日本DDS学会学術集会プログラム予稿集, 37回, 111, 111, 日本DDS学会, 2021年06月
    日本語
  • Delivery of Oligonucleotides Using a Self-Degradable Lipid-Like Material.
    Hiroki Tanaka, Nae Takata, Yu Sakurai, Tokuyuki Yoshida, Takao Inoue, Shinya Tamagawa, Yuta Nakai, Kota Tange, Hiroki Yoshioka, Masatoshi Maeki, Manabu Tokeshi, Hidetaka Akita
    Pharmaceutics, 13, 4, 2021年04月13日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), The world-first success of lipid nanoparticle (LNP)-based siRNA therapeutics (ONPATTRO®) promises to accelerate developments in siRNA therapeutics/gene therapy using LNP-type drug delivery systems (DDS). In this study, we explore the optimal composition of an LNP containing a self-degradable material (ssPalmO-Phe) for the delivery of oligonucleotides. siRNA or antisense oligonucleotides (ASO) were encapsulated in LNP with different lipid compositions. The hepatic knockdown efficiency of the target genes and liver toxicity were evaluated. The optimal compositions for the siRNA were different from those for ASO, and different from those for mRNA that were reported in a previous study. Extracellular stability, endosomal escape and cellular uptake appear to be the key processes for the successful delivery of mRNA, siRNA and ASO, respectively. Moreover, the compositions of the LNPs likely contribute to their toxicity. The lipid composition of the LNP needs to be optimized depending on the type of nucleic acids under consideration if the applications of LNPs are to be further expanded.
  • Simple Approach for Fluorescence Signal Amplification Utilizing a Poly(vinyl alcohol)-Based Polymer Structure in a Microchannel.
    Keine Nishiyama, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Hideaki Hisamoto, Manabu Tokeshi
    ACS omega, 6, 12, 8340, 8345, 2021年03月30日, [査読有り], [最終著者, 責任著者], [国際誌]
    英語, 研究論文(学術雑誌), Analytical methods with fluorescence detection are in widespread use for detecting low abundance analytes. Here, we report a simple method for fluorescence signal amplification utilizing a structure of an azide-unit pendant water-soluble photopolymer (AWP) in a microchannel. The AWP is a poly(vinyl alcohol)-based photocross-linkable polymer, which is often used in biosensors. We determined that the wall-like structure of the AWP (AWP-wall) constructed in a microchannel functioned as an amplifier of a fluorescence signal. When a solution of fluorescent molecules was introduced into the microchannel having the AWP-wall, the fluorescent molecules accumulated inside the AWP-wall by diffusion. Consequently, the fluorescence intensity inside the AWP-wall increased locally. Among the fluorescent molecules considered in this paper, 9H-(1,3-dichloro-9,9-dimethylacridin-2-one-7-yl) (DDAO) showed the highest efficiency of fluorescence signal amplification. We prepared a calibration curve for DDAO using the fluorescence intensity inside the AWP-wall, and the sensitivity was 5-fold that for the microchannel without the AWP-wall. This method realizes the improved sensitivity of fluorescence detection easily because the fluorescence signal was amplified only by injecting the solution into the microchannel having the AWP-wall. Furthermore, since this method is not limited to only the use of microchannel, we expect it to be applicable in various fields.
  • Dip-Type Paper-Based Analytical Device for Straightforward Quantitative Detection without Precise Sample Introduction.
    Takeshi Komatsu, Ryoga Maeda, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    ACS sensors, 6, 3, 1094, 1102, 2021年03月26日, [査読有り], [最終著者, 責任著者], [国際誌]
    英語, 研究論文(学術雑誌), The development of low-cost, user-friendly paper-based analytical devices (PADs) that can easily measure target chemicals is attracting attention. However, most PADs require manipulation of the sample using sophisticated micropipettes for quantitative analyses, which restricts their user-friendliness. In addition, immobilization of detection molecules to cellulose fibers is essential for achieving good measuring ability as it ensures the homogeneity of color development. Here, we have described a dip-type PAD that does not require pipette manipulation for sample introduction and immobilization of detection molecules to cellulose fibers and its application to ascorbic acid (AA) and pH assays. The PAD consisted of a dipping area and two channels, each with two detection zones. The developed PADs show color distribution in the two detection zones depending on the sample flow from the dipping area. In comparison with a PAD that has one detection zone at the end of the channel, our developed device achieved higher sensitivity (limit of detection (LOD), 0.22 mg/mL) and reproducibility (maximum coefficient of variation (CV), 2.4%) in AA detection. However, in pH detection, the reproducibility of the PAD with one detection zone at the end of the channel (maximum CV, 21%) was worse than that with two zones (maximum CV, 11%). Furthermore, a dipping time over 3 s did not affect color formation or calibration curves in AA detection: LODs at 3 and 30 s dipping time were 18 and 5.8 μg/mL, respectively. The simultaneous determination of AA and pH in various beverages was performed with no significant difference compared to results of the conventional method.
  • ミトコンドリア強化ヒト心筋幹細胞(hMITO Cell)の製造および心虚血再灌流モデルを用いた細胞移植療法の検証               
    後藤 悠太, 山田 勇磨, 日比野 光恵, 佐々木 大輔, 武田 充人, 真栄城 正寿, 渡慶次 学, 原島 秀吉
    日本薬学会年会要旨集, 141年会, 29V09, pm09S, (公社)日本薬学会, 2021年03月
    日本語
  • Lipid nanoparticles loaded with ribonucleoprotein-oligonucleotide complexes synthesized using a microfluidic device exhibit robust genome editing and hepatitis B virus inhibition.
    Yuichi Suzuki, Haruno Onuma, Risa Sato, Yusuke Sato, Akari Hashiba, Masatoshi Maeki, Manabu Tokeshi, Mohammad Enamul Hoque Kayesh, Michinori Kohara, Kyoko Tsukiyama-Kohara, Hideyoshi Harashima
    Journal of controlled release, 330, 61, 71, 2021年02月10日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), The clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas) system has considerable therapeutic potential for use in treating a wide range of intractable genetic and infectious diseases including hepatitis B virus (HBV) infections. While non-viral delivery technologies for the CRISPR/Cas system are expected to have clinical applications, difficulties associated with the clinically relevant synthesis of formulations and the poor efficiency of delivery severely hinder therapeutic genome editing. We report herein on the production of a lipid nanoparticle (LNP)-based CRISPR/Cas ribonucleoprotein (RNP) delivery nanoplatform synthesized using a clinically relevant mixer-equipped microfluidic device. DNA cleavage activity and the aggregation of Cas enzymes was completely avoided under the optimized synthetic conditions. The optimized formulation, which was identified through 2 steps of design of experiments, exhibited excellent gene disruption (up to 97%) and base substitution (up to 23%) without any apparent cytotoxicity. The addition of negative charges to the RNPs by complexing single-stranded oligonucleotide (ssON) significantly enhanced the delivery of both Cas9 and Cpf1 RNPs. The optimized formulation significantly suppressed both HBV DNA and covalently closed circular DNA (cccDNA) in HBV-infected human liver cells compared to adeno-associated virus type 2 (AAV2). These findings represent a significant contribution to the development of CRISPR/Cas RNP delivery technology and its practical applications in genome editing therapy.
  • Non-competitive fluorescence polarization immunoassay for detection of H5 avian influenza virus using a portable analyzer.
    Keine Nishiyama, Yohei Takeda, Kazuki Takahashi, Mao Fukuyama, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Koji Shigemura, Akihide Hibara, Haruko Ogawa, Manabu Tokeshi
    Analytical and bioanalytical chemistry, 413, 18, 4619, 4623, 2021年02月05日, [査読有り], [招待有り], [最終著者, 責任著者], [国際誌]
    英語, 研究論文(学術雑誌), Nowadays, the diagnosis of viral infections is receiving broad attention. We have developed a non-competitive fluorescence polarization immunoassay (NC-FPIA), which is a separation-free immunoassay, for a virus detection. H5 subtype avian influenza virus (H5-AIV) was used as a model virus for the proof of concept. The fluorescein-labeled Fab fragment that binds to H5 hemagglutinin was used for NC-FPIA. The purified H5-AIV which has H5 hemagglutinin was mixed with the fluorescein-labeled Fab fragment. After that, the degree of fluorescence polarization was measured with a portable FPIA analyzer. H5-AIV was successfully detected with an incubation time of 15 min. In addition, the portable FPIA analyzer enables performance of on-site NC-FPIA with a sample volume of 20 μL or less. This is the first research of detecting a virus particle by FPIA. This NC-FPIA can be applied to rapid on-site diagnosis of various viruses.
  • One-Step Production Using a Microfluidic Device of Highly Biocompatible Size-Controlled Noncationic Exosome-like Nanoparticles for RNA Delivery
    Niko Kimura, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    ACS APPLIED BIO MATERIALS, 4, 2, 1783, 1793, AMER CHEMICAL SOC, 2021年02月
    英語, 研究論文(学術雑誌), Size-controlled lipid nanoparticle (LNP)-based DNA/RNA delivery is a leading technology for gene therapies. For DNA/RNA delivery, typically, a cationic lipid is used to encapsulate DNA/RNA into LNPs. However, the use of the cationic lipid leads to cytotoxicity. In contrast, noncationic NPs, such as exosomes, are ideal nanocarriers for DNA/RNA delivery. However, the development of a simple one-step method for the production of size-controlled noncationic NPs encapsulating DNA/RNA is still challenging because of the lack of electrostatic interactions between the cationic lipid and negatively charged DNA/RNA. Herein, we report a microfluidic-based one-step method for the production of size-controlled noncationic NPs encapsulating small interfering RNA (siRNA). Our microfluidic device, named iLiNP, enables the efficient encapsulation of siRNA, as well as control over the NP size, by varying the flow conditions. We applied this method to produce size-controlled exosome-like NPs. The siRNA-loaded exosome-like NPs did not show in vitro cytotoxicity at a high siRNA dosage. In addition, we investigated the effect of the size of the exosome-like NPs on the target gene silencing and found that the 40-50 nm-sized NPs suppressed target protein expression at a dose of 20 nM siRNA. The iLiNP-based one-step production method for size-controlled noncationic-NP-encapsulated RNA is a promising method for the production of artificial exosomes and functionally modified exosomes for gene and cell therapies.
  • Rapid, sensitive universal paper-based device enhances competitive immunoassays of small molecules.
    Takeshi Komatsu, Yuki Sato, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Analytica chimica acta, 1144, 85, 95, 2021年02月01日, [査読有り], [最終著者, 責任著者], [国際誌]
    英語, 研究論文(学術雑誌), Competitive immunoassays comprise the standard means of detecting small molecules. However, conventional methods using microwells are difficult to apply during point-of-care tests (POCT) because they require complicated handling and are time consuming. Although paper-based analytical devices (PAD) have received considerable focus because of their rapid and straightforward operation, only a few devices have been proposed for competitive immunoassays. Herein, we describe a novel universal PAD format with a 3-dimensional configuration for competitive immunoassays that rapidly and sensitively detects small molecules. The proposed device comprised a layered structure with uniform color formation and high capture efficiency between antigen and antibody that results in rapid and reproducible results. The device rapidly (90 s) assayed biotin as a model target, with a limit of detection (LOD) of 5.08 ng mL-1, and detected progesterone with an LOD of 84 pg mL-1 within 5 min. Moreover, sample volumes and reagent consumption rates were minimized. Thus, our device could be applied to competitive immunoassays of various small molecules in POCT.
  • Selective Thermal Extraction by Thermoelectric Controller Microfluidic Zinc Oxide Nanowires Device for Artificial Extracellular Vesicle Nanoparticles
    Kunanon Chattrairat, Takao Yasui, Masatoshi Maeki, Manabu Tokeshi, Yoshinobu Baba
    MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1179, 1180, 2021年
    研究論文(国際会議プロシーディングス), Recently, genetic information from miRNAs has provided early diagnosis as biological biomarkers. However, separating free-floating miRNAs from exosomal miRNAs is still challenging due to its nano-size and possible interference in downstream analysis. In this work, we developed an integrated microfluidic ZnO nanowires device with a thermoelectric controller for separating free-floating miRNA (ff-miRNAs) from miRNA-encapsulated artificial extracellular vesicles nanoparticles (NPs).
  • PEGylation of Silver Nanoparticles by Physisorption of Cyclic Poly(Ethylene Glycol) for Enhanced Dispersion Stability, Antimicrobial Activity, and Cytotoxicity
    Onyinyechukwu Oziri, Yubo Wang, Tomohisa Watanabe, Shuya Uno, Masatoshi Maeki, Manabu Tokeshi, Takuya Isono, Kenji Tajima, Toshifumi Satoh, Shin-ichiro Sato, Yutaka Miura, Takuya Yamamoto
    Nanoscale Advances, 4, 2, 532, 545, Royal Society of Chemistry (RSC), 2021年
    研究論文(学術雑誌), Silver nanoparticles (AgNPs) are practically valuable in biological applications. However, no steady PEGylation has been established, which is essential for internal use in humans or animals. In this study, cyclic...
  • Three-dimensional, symmetrically assembled microfluidic device for lipid nanoparticle production
    Niko Kimura, Masatoshi Maeki, Kosuke Sasaki, Yusuke Sato, Akihiko Ishida, Hirofumi Tani, Hideyoshi Harashima, Manabu Tokeshi
    RSC ADVANCES, 11, 3, 1430, 1439, ROYAL SOC CHEMISTRY, 2021年01月
    英語, 研究論文(学術雑誌), Sub 100 nm-sized lipid nanoparticles (LNPs) have been widely used in drug delivery systems (DDSs). The size of the LNPs is an important parameter for the DDS performance, such as biodistribution and gene silencing using siRNAs. However, the LNPs prepared by the conventional preparation method show a wide size distribution. To improve the LNP size distribution, we developed a microfluidic device, named the iLiNP (TM) device, in a previous study. This device could produce LNPs in the size range of 20 to 150 nm, but the size distribution of the large-sized LNPs needs to be further improved. From the viewpoint of the LNP formation process, a homogeneous and slow rate dilution of ethanol plays an important role in improving the large-size LNP size distribution. In this study, we developed a three-dimensional, symmetrically assembled microfluidic device named the 3D-iLiNP device with the aim of precise size control of large-sized LNPs. We designed the 3D-iLiNP device using a computational fluid dynamics simulation and demonstrated that the 3D-iLiNP device can improve the LNP size distribution. The gene silencing activity of four kinds of siRNA-loaded LNPs was investigated via in vitro and in vivo experiments to elucidate the effect of the LNP size distribution. The results revealed that the LNPs with a size between 90 and 120 nm showed higher gene silencing activity than those with other sizes. The 3D-iLiNP device is expected to improve DDS performance by precisely controlling the size of LNPs.
  • Enhanced dispersion stability of gold nanoparticles by the physisorption of cyclic poly(ethylene glycol).
    Yubo Wang, Jose Enrico Q Quinsaat, Tomoko Ono, Masatoshi Maeki, Manabu Tokeshi, Takuya Isono, Kenji Tajima, Toshifumi Satoh, Shin-Ichiro Sato, Yutaka Miura, Takuya Yamamoto
    Nature communications, 11, 1, 6089, 6089, 2020年11月30日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Nano-sized metal particles are attracting much interest in industrial and biomedical applications due to the recent progress and development of nanotechnology, and the surface-modifications by appropriate polymers are key techniques to stably express their characteristics. Herein, we applied cyclic poly(ethylene glycol) (c-PEG), having no chemical inhomogeneity, to provide a polymer topology-dependent stabilization for the surface-modification of gold nanoparticles (AuNPs) through physisorption. By simply mixing c-PEG, but not linear counterparts, enables AuNPs to maintain dispersibility through freezing, lyophilization, or heating. Surprisingly, c-PEG endowed AuNPs with even better dispersion stability than thiolated PEG (HS-PEG-OMe). The stronger affinity of c-PEG was confirmed by DLS, ζ-potential, and FT-IR. Furthermore, the c-PEG system exhibited prolonged blood circulation and enhanced tumor accumulation in mice. Our data suggests that c-PEG induces physisorption on AuNPs, supplying sufficient stability toward bio-medical applications, and would be an alternative approach to the gold-sulfur chemisorption.
  • The use of design of experiments with multiple responses to determine optimal formulations for in vivo hepatic mRNA delivery.
    Akari Hashiba, Manaya Toyooka, Yusuke Sato, Masatoshi Maeki, Manabu Tokeshi, Hideyoshi Harashima
    Journal of controlled release, 327, 467, 476, 2020年11月10日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Although great advances have been made in the delivery of short RNAs by lipid nanoparticles (LNPs), the optimal formulation composition and physicochemical properties of LNPs for long RNA (including mRNA) remain unclear. In the present study, we optimized the lipid composition of liver-targeted mRNA-loaded LNPs that were prepared with pH-sensitive cationic lipids that had been previously designed for siRNA delivery through a two stepped design of experiment (DoE). Multiple responses including physicochemical properties, gene expression, and liver-specificity were analyzed in order, not only to understand the role of each formulation parameter, but also to examine parameters that would be difficult to predict. We found that particle size and the PEG-to-phospholipid (PEG/PL) ratio were additional key factors for liver-specific gene expression in addition to the other formulation factors. The optimized formulation showed a better gene expression compared to other lipid formulations from industry leaders. These findings suggest that a "DoE with multiple responses" approach can be used to predict significant parameters and permit optimized formulations to be prepared more efficiently.
  • Noncompetitive Fluorescence Polarization Immunoassay for Protein Determination.
    Mao Fukuyama, Ayano Nakamura, Keine Nishiyama, Ayuko Imai, Manabu Tokeshi, Koji Shigemura, Akihide Hibara
    Analytical chemistry, 92, 21, 14393, 14397, 2020年11月03日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Fluorescent polarization immunoassay (FPIA) is a single-step immunoassay method that is applicable to point-of-care testing; however, its applicability to large biomolecules has been restricted because ordinary FPIA is a competitive assay. Here, we report a noncompetitive FPIA using the variable domain from the heavy chain of a camelid antibody (VHH antibody). FPIA with VHH was successfully used to quantitate rabbit immunoglobulin G (IgG) and demonstrated a wider response range than that observed with antibody-binding (Fab) fragment. Then, using a portable FPIA instrument, a VHH-based immunoassay of human IgG in a human serum certified reference material was demonstrated.
  • Silica Nanopillar Arrays for Monitoring Diffraction-Based Label-Free Biomolecule Separation
    Taiga Ajiri, Takao Yasui, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Junji Nishii, Yoshinobu Baba, Manabu Tokeshi
    ACS APPLIED NANO MATERIALS, 3, 9, 8810, 8816, AMER CHEMICAL SOC, 2020年09月
    英語, 研究論文(学術雑誌), Recent studies on nanopillar arrays, one type of nanofluidic device, have demonstrated various tools for bioanalysis. When carrying out nanopillar array-based separation, it is indispensable to observe biomolecules, such as DNA, proteins, and extracellular vesicles, that have fluorescence labeling; however, fluorescence labeling influences the biomolecular characteristics. Here, we have proposed label-free monitoring of biomolecule separation by using diffracted light derived from the nanopillar array that was fabricated inside a microchannel by combining laser interference lithography with general photolithography techniques. Using an electrophoresis approach, we demonstrated that our diffraction-based label-free method possessed high sensor initialization ability, and the nanopillar array device successfully monitored DNA separation without labeling bias. Results obtained using our label-free monitoring of DNA separation confirmed, for the first time, that the molecular dynamics of DNA molecules in the nanopillar array were changed in the presence or absence of fluorescent labeling. The presented concept will provide a useful tool for nonbiased monitoring of label-free biomolecule analysis in nanofluidic channels.
  • Room-temperature crystallography using a microfluidic protein crystal array device and its application to protein-ligand complex structure analysis
    Masatoshi Maeki, Sho Ito, Reo Takeda, Go Ueno, Akihiko Ishida, Hirofumi Tani, Masaki Yamamoto, Manabu Tokeshi
    CHEMICAL SCIENCE, 11, 34, 9072, 9087, ROYAL SOC CHEMISTRY, 2020年09月
    英語, 研究論文(学術雑誌), Room-temperature (RT) protein crystallography provides significant information to elucidate protein function under physiological conditions. In particular, contrary to typical binding assays, X-ray crystal structure analysis of a protein-ligand complex can determine the three-dimensional (3D) configuration of its binding site. This allows the development of effective drugs by structure-based and fragmentbased (FBDD) drug design. However, RT crystallography and RT crystallography-based protein-ligand complex analyses require the preparation and measurement of numerous crystals to avoid the X-ray radiation damage. Thus, for the application of RT crystallography to protein-ligand complex analysis, the simultaneous preparation of protein-ligand complex crystals and sequential X-ray diffraction measurement remain challenging. Here, we report an RT crystallography technique using a microfluidic protein crystal array device for protein-ligand complex structure analysis. We demonstrate the microfluidic sorting of protein crystals into microwells without any complicated procedures and apparatus, whereby the sorted protein crystals are fixed into microwells and sequentially measured to collect X-ray diffraction data. This is followed by automatic data processing to calculate the 3D protein structure. The microfluidic device allows the high-throughput preparation of the protein-ligand complex solely by the replacement of the microchannel content with the required ligand solution. We determined eight trypsin-ligand complex structures for the proof of concept experiment and found differences in the ligand coordination of the corresponding RT and conventional cryogenic structures. This methodology can be applied to easily obtain more natural structures. Moreover, drug development by FBDD could be more effective using the proposed methodology.
  • One-step non-competitive fluorescence polarization immunoassay based on a Fab fragment for C-reactive protein quantification
    Keine Nishiyama, Mao Fukuyama, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Akihide Hibara, Manabu Tokeshi
    Sensors and Actuators B: Chemical, 128982, 128982, Elsevier BV, 2020年09月, [査読有り], [最終著者, 責任著者]
    研究論文(学術雑誌)
  • Rapid detection of anti-H5 avian influenza virus antibody by fluorescence polarization immunoassay using a portable fluorescence polarization analyzer.
    Keine Nishiyama, Yohei Takeda, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Koji Shigemura, Akihide Hibara, Yutaka Yonezawa, Kunitoshi Imai, Haruko Ogawa, Manabu Tokeshi
    Sensors and actuators. B, Chemical, 316, 128160, 128160, 2020年08月01日, [査読有り], [最終著者, 責任著者], [国際誌]
    英語, 研究論文(学術雑誌), A rapid, facile and selective detection of anti-H5 subtype avian influenza virus (AIV) antibody in serum by fluorescence polarization immunoassay (FPIA) was achieved. A fragment of recombinant H5 subtype AIV hemagglutinin was produced and labeled with fluorescein to use it as a labeled antigen in FPIA. This labeled antigen was mixed with anti-AIV sera (H1-H16 subtypes) and FP of the mixture was measured using a portable FP analyzer on a microdevice. It was found that FP increased in proportion to the concentration of anti-H5 AIV antibody (serum) and was significantly higher than FP obtained with the other sera. The selective detection of anti-H5 subtype AIV antibody was confirmed. The required volume of original sample was 2 μL and analysis time was within 20 min. This detection system realizes an efficient on-site diagnosis and surveillance of AIV.
  • Development of a Microfluidic-Based Post-Treatment Process for Size-Controlled Lipid Nanoparticles and Application to siRNA Delivery.
    Niko Kimura, Masatoshi Maeki, Yusuke Sato, Akihiko Ishida, Hirofumi Tani, Hideyoshi Harashima, Manabu Tokeshi
    ACS applied materials & interfaces, 12, 30, 34011, 34020, 2020年07月29日, [査読有り], [最終著者, 責任著者], [国際誌]
    英語, 研究論文(学術雑誌), Microfluidic methodologies for preparation of lipid nanoparticles (LNPs) based on an organic solvent injection method enable precise size control of the LNPs. After preparation of LNPs, the organic solvent injection method needs some post-treatments, such as overnight dialysis or direct dilution with a buffer solution. LNP production using the microfluidic-based organic solvent injection method is dominated by kinetics rather than thermodynamics. Kinetics of ethanol removal from the inner and outer membranes of LNPs could induce a structural change in the membrane that could lead to fusion of LNPs. However, the effects of microfluidic post-treatment on the final size of LNPs have not been sufficiently understood. Herein, we investigated the effect of the post-treatment processes on the final product size of LNPs in detail. A simple baffle device and a model lipid system composed of a neutral phospholipid (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, POPC) and cholesterol were used to produce the LNPs. We demonstrated that flow conditions of the post-treatment diluting the remaining ethanol in the LNP suspension affected the final product size of LNPs. Based on the findings, we developed an integrated baffle device composed of an LNP production region and a post-treatment region for a microfluidic-based LNP production system; this integrated baffle device prevented the undesirable aggregation or fusion of POPC LNPs even for the high-lipid-concentration condition. Finally, we applied our concept to small interfering RNA (siRNA) delivery and confirmed that no significant effects due to the continuous process occurred on the siRNA encapsulation efficiency, biological distribution, and knockdown activity. The microfluidic post-treatment method is expected to contribute to the production of LNPs for practical applications and the development of novel LNP-based nanomedicines.
  • Real-Time Measurement of Protein Crystal Growth Rates within the Microfluidic Device to Understand the Microspace Effect.
    Masatoshi Maeki, Shohei Yamazaki, Reo Takeda, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    ACS omega, 5, 28, 17199, 17206, 2020年07月21日, [査読有り], [最終著者, 責任著者], [国際誌]
    英語, 研究論文(学術雑誌), Preparation of high-quality protein crystals is a major challenge in protein crystallography. Natural convection is considered to be an uncontrollable factor of the crystallization process at the ground level as it disturbs the concentration gradient around the growing crystal, resulting in lower-quality crystals. A microfluidic environment expects an imitated microgravity environment because of the small Gr number. However, the mechanism of protein crystal growth in the microfluidic device was not elucidated due to limitations in measuring the crystal growth process within the device. Here, we demonstrate the real-time measurement of protein crystal growth rates within the microfluidic devices by laser confocal microscopy with differential interference contrast microscopy (LCM-DIM) at the nanometer scale. We confirmed the normal growth rates in the 20 and 30 μm-deep microfluidic device to be 42.2 and 536 nm/min, respectively. In addition, the growth rate of crystals in the 20 μm-deep microfluidic device was almost the same as that reported in microgravity conditions. This phenomenon may enable the development of more accessible alternatives to the microgravity environment of the International Space Station.
  • Observation of Ethanol-Induced Condensation and Decondensation Processes at a Single-DNA Molecular Level in Microfluidic Devices Equipped with a Rapid Solution Exchange System.
    Hiroshi Suzuki, Kentaro Fujiyoshi, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Analytical chemistry, 92, 13, 9132, 9137, 2020年07月07日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Conformational transitions from secondary (e.g., B- to A-form DNA) to higher-order (e.g., coil to globule) transitions play important roles in genome expression and maintenance. Several single-molecule approaches using microfluidic devices have been used to determine the kinetics of DNA chromatin assembly because microfluidic devices can afford stretched DNA molecules through laminar flow and rapid solution exchange. However, some issues, particularly the uncertainty of time 0 in the solution exchange process, are encountered. In such kinetic experiments, it is critical to determine when the target solution front approaches the target DNA molecules. Therefore, a new design for a microfluidic device is developed that enables the instantaneous exchange of solutions in the observation channel, allowing accurate measurements of DNA conformational transitions; stepwise, ethanol-induced conformational transitions are revealed. Although full DNA contraction from coil to globule is observed with >50% ethanol, no outstanding change is observed at concentrations <40% in 10 min. With 50% ethanol solution, the DNA conformational transition passes through two steps: (i) fast and constant-velocity contraction and (ii) relatively slow contraction from the free end. The first process is attributed to the B to A conformational transition by gradual dehydration. The second process is due to the coil-globule transition as the free end of DNA starts the contraction. This globular structure formation counteracts the shear force from the microfluids and decelerates the contraction velocity. This real-time observation system can be applied to the kinetic analysis of DNA conformational transitions such as kinetics of chromatin assembly and gene expression.
  • Paper-Based Device for the Facile Colorimetric Determination of Lithium Ions in Human Whole Blood.
    Takeshi Komatsu, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    ACS sensors, 5, 5, 1287, 1294, 2020年05月22日, [査読有り], [最終著者, 責任著者], [国際誌]
    英語, 研究論文(学術雑誌), Lithium carbonate is an effective medicine for the treatment of the bipolar disorder, but the concentration of lithium in the patient's blood must be frequently monitored because of its toxicity. To date, no colorimetric methods of lithium ion detection in whole blood without pretreatment have been reported. Here, we report a colorimetric paper-based device that allows point-of-care testing in one step. This device is composed of two paper-based elements linked to each other: a blood cell separation unit and a colorimetric detection unit. After a portion of whole blood has been placed on the end of the separation unit, plasma in the sample is automatically transported to the detection unit, which displays a diagnostic color. The key feature of this device is its simple, user-friendly operation. The limit of detection is 0.054 mM and the coefficient of variance is below 6.1%, which are comparable to those of conventional instruments using the same colorimetric reaction. Furthermore, we achieved high recovery (>90%) and reproducibility (<9.8%) with spiked human blood samples. Thus, the presented device provides an alternative method for the regular monitoring of lithium concentrations in the treatment of bipolar disorder by augmenting the coefficient of variation (maximum value, 6.1%).
  • 脂質ナノ粒子の特性がリンパ節送達とリンパ節内分布へ与える影響               
    中村 孝司, 河合 美典, 佐藤 悠介, 真栄城 正寿, 渡慶次 学, 原島 秀吉
    日本薬剤学会年会講演要旨集, 35年会, 171, 171, (公社)日本薬剤学会, 2020年05月
    日本語
  • The Effect of Size and Charge of Lipid Nanoparticles Prepared by Microfluidic Mixing on Their Lymph Node Transitivity and Distribution.
    Takashi Nakamura, Minori Kawai, Yusuke Sato, Masatoshi Maeki, Manabu Tokeshi, Hideyoshi Harashima
    Molecular pharmaceutics, 17, 3, 944, 953, 2020年03月02日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Because the lymph node (LN) is a critical organ for inducing immune responses against pathogens and cancers, the transport of immune functional molecules such as antigens and adjuvants to LNs by delivery systems is a useful strategy for the effective outcome of an immune response. The size and charge of a delivery system largely affect the transitivity to and distribution within LN. Although pH-sensitive lipid nanoparticles (LNPs) prepared by microfluidic mixing are the latest delivery system to be applied clinically, the effects of their size and charge on the transitivity to and distribution within LN are currently unknown. We investigated the size and charge effect of LNPs prepared by microfluidic mixing on transitivity to and distribution within LNs. A 30 nm-sized LNP (30-LNP) was efficiently translocated to LNs and was taken up by CD8+ dendritic cells, while the efficiency was drastically decreased in the cases of 100 and 200 nm-sized LNPs. Furthermore, a comparative study between neutral, positively, and negatively charged 30-LNP revealed that the negative 30-LNP moved to the LN more efficiently than the other LNPs. Interestingly, the negative 30-LNP reached the deep cortex, namely, the T cell zone. Our findings provide informative insights for designing LN-targeting LNPs prepared by microfluidic mixing and for the translocation of nanoparticles in LNs.
  • Hydrophobic scaffolds of pH-sensitive cationic lipids contribute to miscibility with phospholipids and improve the efficiency of delivering short interfering RNA by small-sized lipid nanoparticles.
    Yusuke Sato, Nana Okabe, Yusuke Note, Kazuki Hashiba, Masatoshi Maeki, Manabu Tokeshi, Hideyoshi Harashima
    Acta biomaterialia, 102, 341, 350, 2020年01月15日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Despite the fact that small-sized lipid nanoparticles (LNPs) are important for improved tissue penetration and efficient drug delivery, their poor stability and intracellular trafficking significantly hinders their use as potent small-sized LNPs. It has been reported that both the diffusion of lipid components from LNPs and the adsorption of proteins on the surface of LNPs are responsible for their decreased potency. To overcome this issue, we focused on the chemical structure of hydrophobic scaffolds of pH-sensitive cationic lipids with various lengths and shapes. LNPs composed of a pH-sensitive cationic lipid with long, linear scaffolds induced gene silencing in a dose-dependent manner, while LNPs with a classical scaffold length (C18) failed. Replacing the helper lipid from cholesterol to egg sphingomyelin (ESM) resulted in the formation of smaller LNPs with a diameter of ~22 nm and enhanced gene silencing activity. Most of the ESMs were located in the outer layer and functioned to stabilize the LNPs. Long, linear scaffolds contributed to immiscibility with phosphocholine-containing lipids including ESM. This contribution was dependent on the scaffold length of pH-sensitive cationic lipids. Although phosphocholine-containing lipids usually inhibit membrane fusion-mediated endosomal escape, long, linear scaffolds contributed to avoiding the inhibitory effect and to enhance the potency of the LNPs. These findings provide useful information needed for the rational design of pH-sensitive cationic lipid structures and the selection of appropriate helper lipids and will facilitate the development of highly potent small-sized LNPs. STATEMENT OF SIGNIFICANCE: Despite the fact that small-sized lipid nanoparticles (LNPs) are important for improved tissue penetration and efficient drug delivery, the size reduction-associated decrease in the stability and intracellular trafficking significantly hinders the development of potent small-sized LNPs. Our limited understanding of the mechanism underlying the reduced potency has also hindered the development of more potent small-sized LNPs. The findings of the present study indicate that long and linear hydrophobic scaffolds of pH-sensitive cationic lipids could overcome the loss of efficiency for nucleic acid delivery. In addition, the long hydrophobic scaffolds led to immiscibility with neutral phospholipids, resulting in efficient endosomal escape. These findings provide useful information needed for the rational design of pH-sensitive cationic lipid structures and will facilitate the development of highly potent small-sized LNPs.
  • Development of a Paper-based Analytical Chip for the Detection of Bacterial 16S rRNA in Wastewater Samples
    Meri Nakajima, Akihiko Ishida, Manabu Tokeshi, Hisashi Satoh
    BUNSEKI KAGAKU, 69, 12, 715, 722, JAPAN SOC ANALYTICAL CHEMISTRY, 2020年
    日本語, 研究論文(学術雑誌), Analysis of bacteria in the sewage wastewater treatment process is essential for process stabilization and upgrading. Although bacteria are currently being analyzed by molecular biology techniques targeting the 16S rRNA gene, there is a problem that they are time-consuming and labor-intensive. In this study, we developed a paper-based analytical chip by using two types of DNA molecules that specifically bind to bacterial 16S rRNA. We optimized the fabrication method of the detection probe and the paper-based analytical chip, and then detected synthetic DNA having a nucleotide sequence that hybridizes with the designed DNA molecules and bacterial 16S rRNA extracted from an activated sludge sample. We evaluated the amount of nucleic acids quantitatively by taking images of the detection line on the paper-based analytical chip with a smartphone and analyzing its brightness with an open-source image processing program, ImageJ. Our method was able to detect 85 nM of bacterial 16S rRNA concentration in the extract. Nucleic acids that did not hybridize with either of the designed DNA molecules were not detected, demonstrating high selectivity of our method.
  • An aprotic polar solvent assisted size-tuning method for microfluidic production of lipid-based drug nanocarriers with various sizes
    Niko Kimura, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    MicroTAS 2020 - 24th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1021, 1022, 2020年
    研究論文(国際会議プロシーディングス), This paper reports a microfluidic methodology for precise size-tuning of lipid nanoparticles (LNPs) with various sizes by using lipid solvents composed of a protic or an aprotic or mixed solvents. This method expanded the size-tunable range of the iLiNP device while kept the precise size controllability and the mass productivity. In addition, the produced siRNA-loaded LNPs with various sizes were evaluated in vitro experiments and confirmed effective gene-silencing activity and intracellular uptake depending on the LNP sizes. This LNP size-tuning methodology is expected to be a breakthrough in the current limited size-tunability of LNPs.
  • Novel format of a paper-based device for competitive immunoassays
    Takeshi Komatsu, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    MicroTAS 2020 - 24th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 494, 495, 2020年
    研究論文(国際会議プロシーディングス), We report a new microfluidic paper-based analytical device (μPAD) that allows competitive immunoassays without washing operations. This device consists of three layers and has the following features: (1) uniform color development, (2) high controllability of wicking rate, (3) rapid and highly sensitive measurement. The performance of the device was evaluated by the biotin/anti-biotin antibody assay, and then was successfully applied to the sensitive measurement of progesterone (female sex hormone).
  • Detection of avian influenza virus and its antibody by fluorescence polarization immunoassay
    Keine Nishiyama, Yohei Takeda, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Koji Shigemura, Akihide Hibara, Haruko Ogawa, Manabu Tokeshi
    MicroTAS 2020 - 24th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1226, 1227, 2020年
    研究論文(国際会議プロシーディングス), This paper reports a high-throughput and rapid method for a fluorescence polarization immunoassay (FPIA) of H5-avian influenza virus (H5-AIV) and anti-H5-AIV antibody using a portable FP analyzer with a microdevice. For both assays, a fluorescein-labeled recombinant fragment of H5-hemagglutinin was prepared. Although the labeled fragment had low molecular-weight, it served as a tracer for the FPIA. Also, a microdevice having multiplex microchannels was designed, allowing simultaneous multiplex analysis at a small sample volume. Consequently, the virus and the antibody in several samples were successfully detected rapidly in the same format.
  • Development of an immuno-wall device for the rapid and sensitive detection of EGFR mutations in tumor tissues resected from lung cancer patients.
    Naoyuki Yogo, Tetsunari Hase, Toshihiro Kasama, Keine Nishiyama, Naoya Ozawa, Takahiro Hatta, Hirofumi Shibata, Mitsuo Sato, Kazuki Komeda, Nozomi Kawabe, Kohei Matsuoka, Toyofumi Fengshi Chen-Yoshikawa, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Yoshinori Hasegawa
    PloS one, 15, 11, e0241422, 2020年, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Detecting molecular targets in specimens from patients with lung cancer is essential for targeted therapy. Recently, we developed a highly sensitive, rapid-detection device (an immuno-wall device) that utilizes photoreactive polyvinyl alcohol immobilized with antibodies against a target protein via a streptavidin-biotin interaction. To evaluate its performance, we assayed epidermal growth factor receptor (EGFR) mutations, such as E746_A750 deletion in exon 19 or L858R substitution in exon 21, both of which are common in non-small cell lung cancer and important predictors of the treatment efficacy of EGFR tyrosine kinase inhibitors. The results showed that in 20-min assays, the devices detected as few as 1% (E746_A750 deletion) and 0.1% (L858R substitution) of mutant cells. Subsequent evaluation of detection of the mutations in surgically resected lung cancer specimens from patients with or without EGFR mutations and previously diagnosed using commercially available, clinically approved genotyping assays revealed diagnostic sensitivities of the immuno-wall device for E746_A750 deletion and L858R substitution of 85.7% and 87.5%, respectively, with specificities of 100% for both mutations. These results suggest that the immuno-wall device represents a good candidate next-generation diagnostic tool, especially for screening of EGFR mutations.
  • An Electrochemical Sensor Based on Structure Switching of Dithiol-modified Aptamer for Simple Detection of Ochratoxin A.
    Donny Nugraha Mazaafrianto, Akihiko Ishida, Masatoshi Maeki, Hirofumi Tani, Manabu Tokeshi
    Analytical sciences, 35, 11, 1221, 1226, 2019年11月10日, [査読有り], [最終著者, 責任著者], [国内誌]
    英語, 研究論文(学術雑誌), In this study, we developed an electrochemical sensor for ochratoxin A (OTA) by using an aptamer having a dithiol-based anchor, which exhibited higher stability on a gold electrode than a monothiol-based aptamer because of its two anchors. The sensor was also based on a signal-on scheme that produces a signal current resulting from structure-switching of the aptamer upon interaction with OTA. For simple fabrication of this sensor, the non-covalent interaction of methylene blue with the aptamer was also employed as an electrochemical indicator. In this study, the performance of the sensor, including the dissociation constant of the aptamer-OTA complex, was characterized. The proposed sensor exhibited high reproducibility and enough sensitivity to detect the minimum amount of OTA required for the analysis of real food samples with a limit of detection of 113 pM.
  • A paper-based analytical device coupled with electrochemical detection for the determination of dexamethasone and prednisolone in adulterated traditional medicines.
    Vitsarut Primpray, Orawon Chailapakul, Manabu Tokeshi, Theerasak Rojanarata, Wanida Laiwattanapaisal
    Analytica chimica acta, 1078, 16, 23, 2019年10月31日, [査読有り], [国際共著], [国際誌]
    英語, 研究論文(学術雑誌), The adulteration of herbal medicines by dexamethasone or prednisolone is regarded as a serious problem in many communities. Herein, a novel platform for the separation and quantification of both target steroids in herbal medicines based on electrochemical paper-based analytical devices (ePADs) has been created. The ePAD was composed of Whatman SG81 chromatography paper, 3D-printed devices and a commercial screen-printed electrode. Whatman SG81 silica-coated paper was used for the separation of dexamethasone and prednisolone based on the difference in their partition coefficients during the flow of the mobile phase. The optimal mobile phase was composed of 60% ethyl acetate in cyclohexane and required 7 min for separation. The separated steroids on the paper were then quantified by electrochemical detection using differential pulse voltammetry, in which the 3D-printed devices facilitated the measurement. Analytical detection ranges of 10-500 μg mL-1 were obtained for both dexamethasone and prednisolone (r2 = 0.988 and 0.994, respectively). The limits of detection for dexamethasone and prednisolone were 3.59 and 11.98 μg mL-1, respectively, whereas the limits of quantification were 6.00 and 20.02 μg mL-1, respectively. The amounts of both target steroids derived from real herbal medicine samples determined by the proposed method were comparable to those obtained with assays using standard high-performance liquid chromatography. In addition, a simple evaporation step can be used to increase the concentration of the samples before analysis. These ePADs are simple, low-cost, rapid, and very promising for on-site quantitative detection.
  • Rapid, Sensitive, and Selective Detection of H5 Hemagglutinin from Avian Influenza Virus Using an Immunowall Device.
    Kenia Chávez Ramos, Keine Nishiyama, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Toshihiro Kasama, Yoshinobu Baba, Manabu Tokeshi
    ACS omega, 4, 15, 16683, 16688, 2019年10月08日, [査読有り], [最終著者, 責任著者], [国際共著], [国際誌]
    英語, 研究論文(学術雑誌), Avian influenza virus (AIV) infection, caused by influenza virus type A, is an infectious, acute respiratory disease of birds related to influenza outbreaks worldwide. The highly pathogenic AIV subtype H5N1 has crossed species barriers to infect mammals, including humans, with fatal outcomes and has received attention as a potential pandemic threat. A rapid and timely detection in poultry is vitally important to prevent the virus spread. Despite their great sensitivity, conventional detection methods such as real-time reverse transcription-polymerase chain reaction and the agar gel precipitation test are time-consuming and labor-intensive and require special training. In this work, an immunowall device was evaluated as an easier and faster way for detecting AIV H5-hemagglutinin (AIV H5-HA). For detection, fluorescence-labeled or enzyme-labeled antibody was employed as a labeling antibody in a sandwich immunoassay. Both were shown in this paper to be easier and faster assays for detection compared with the conventional enzyme-linked immunosorbent assay (ELISA) kit. In addition, high selectivity was achieved for AIV H5-HA detection after the evaluation of other different HA virus subtypes. The limit of detection was 0.23 ng/mL for the enzyme-labeled antibody. This value was equivalent to that of the conventional ELISA kit but 8 times faster (31 min compared to 260 min). The detection range was 0.23-100 ng/mL. The immunowall device with the enzyme-labeled antibody offers a rapid, sensitive, selective, and simple immunoassay system for future H5 AIV real sample detection.
  • High-throughput fluorescence polarization immunoassay by using a portable fluorescence polarization imaging analyzer.
    Osamu Wakao, Ken Satou, Ayano Nakamura, Polina A Galkina, Keine Nishiyama, Ken Sumiyoshi, Fumio Kurosawa, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Mikhail A Proskurnin, Koji Shigemura, Akihide Hibara, Manabu Tokeshi
    Lab on a chip, 19, 15, 2581, 2588, 2019年08月07日, [査読有り], [最終著者, 責任著者], [国際共著], [国際誌]
    英語, 研究論文(学術雑誌), High-throughput fluorescence polarization immunoassays (FPIAs) for mycotoxin were conducted using a portable FP analyzer with a microdevice. Simultaneous FPIA measurements for 8 different deoxynivalenol (DON) concentrations in 12 chambers (total of 96 samples) and high-throughput FPIA measurements for single DON concentrations in more than 500 chambers were conducted. The results indicated that simultaneous FPIAs for 96 independent samples and for 500 samples were possible by FP imaging. The FP analyzer has a size of 65 cm (W 35 cm × D 15 cm × H 15 cm) and costs less than $5000. The sample volume was 1 nL. Furthermore, it is expected that sample reaction and FP detection can be automatically conducted with the analyzer by changing the microdevice and the software. Its features such as low cost and portability will contribute to on-site measurement and point-of-care testing. Additionally, the high-throughput feature will contribute to the study of molecular interactions based on FP measurements.
  • Ultrasensitive detection of disease biomarkers using an immuno-wall device with enzymatic amplification.
    Keine Nishiyama, Toshihiro Kasama, Seiya Nakamata, Koya Ishikawa, Daisuke Onoshima, Hiroshi Yukawa, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Yoshinobu Baba, Manabu Tokeshi
    The Analyst, 144, 15, 4589, 4595, 2019年08月07日, [査読有り], [最終著者, 責任著者], [国際誌]
    英語, 研究論文(学術雑誌), We present an ultrasensitive immunoassay system for disease biomarkers utilizing the immuno-wall device and an enzymatic amplification reaction. The immuno-wall device consisted of 40 microchannels, each of which contained an antibody-modified wall-like structure along the longitudinal axis of the microchannel. The wall was fabricated with a water-soluble photopolymer containing streptavidin by photolithography, and biotinylated capture antibodies were immobilized on the sides through streptavidin-biotin interaction. For an assay, introducing the target biomarker and secondary and labeled antibodies produced a sandwich complex anchored on the sides of the wall. A conventional immuno-wall device uses a fluorescence-labeled antibody as a labeling antibody. To achieve an ultrasensitive detection of a trace biomarker, we used an enzyme label and amplified the signal with the enzymatic reaction with a fluorogenic substrate in the microchannel. The highest signal/background ratio was obtained by using alkaline phosphatase-labeled antibody and 9H-(1,3-dichloro-9,9-dimethylacridin-2-one-7-yl) phosphate. To evaluate the device performance, we detected human C-reactive protein (CRP) as a model biomarker. The detection limit (LOD) of CRP in phosphate-buffered saline was 2.5 pg mL-1 with a sample volume of 0.25 μL. This LOD was approximately 3 orders of magnitude lower than that obtained with fluorescent-dye (DyLight 650)-labeled antibody. In addition, the present device provided a wide detection range of 0.0025-10 ng mL-1 for CRP. We successfully developed an ultrasensitive immunoassay system with simple operation and only a small sample volume.
  • The Use of a Microfluidic Device to Encapsulate a Poorly Water-Soluble Drug CoQ10 in Lipid Nanoparticles and an Attempt to Regulate Intracellular Trafficking to Reach Mitochondria.
    Mitsue Hibino, Yuma Yamada, Naoki Fujishita, Yusuke Sato, Masatoshi Maeki, Manabu Tokeshi, Hideyoshi Harashima
    Journal of pharmaceutical sciences, 108, 8, 2668, 2676, 2019年08月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), A number of drugs that are currently on the market, as well as new candidates for drugs, are poorly water soluble. Because of this, a need exists to develop drug formulations that will permit the expanded use of such drugs. The use of liposomes and lipid nanoparticles for drug delivery has attracted attention as a technique for solubilizing molecules that are poorly water soluble, but this technique faces serious scale-up risks. In this study, we report on attempts to encapsulate Coenzyme Q10 (CoQ10) as a model of a poorly water-soluble drug in an MITO-Porter, a liposome for mitochondrial delivery using a microfluidic device (a CoQ10-MITO-Porter [μ]). The physical properties of the CoQ10-MITO-Porter [μ] including homogeneity, size, and preparation volume were compared with those for a CoQ10-MITO-Porter prepared by the ethanol dilution method (a CoQ10-MITO-Porter [ED]). In the case where a microfluidic device was used, a small-sized CoQ10-MITO-Porter was formed homogeneously, and it was possible to prepare it on a large scale. Intracellular observations using HeLa cells showed that the CoQ10-MITO-Porter [μ] was efficiently internalized by cells to reach mitochondria. These results indicate that the CoQ10-MITO-Porter [μ] represents a potential candidate for use in mitochondrial nanomedicine.
  • A Concentric Ring Array Electrode for a Wall-Jet Cell in a Microfluidic Device               
    Keine Nishiyama, Koki Hoshikawa, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Electroanalysis, 31, 1736, 1743, 2019年06月, [査読有り], [最終著者, 責任著者]
    英語, 研究論文(学術雑誌)
  • マイクロ流体デバイス 薬剤学研究・開発のツールとして
    西山 慶音, 木村 笑, 真栄城 正寿, 渡慶次 学
    薬剤学: 生命とくすり, 79, 3, 124, 129, (公社)日本薬剤学会, 2019年05月
    日本語
  • Sensitive Fluorescent Polarization Immunoassay by Optimizing Synchronization Mismatch Condition
    Osamu Wakao, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Akihide Hibara, Manabu Tokeshi
    Sensors and Actuators B, 285, 418, 422, ELSEVIER SCIENCE SA, 2019年04月, [査読有り], [最終著者, 責任著者]
    英語, 研究論文(学術雑誌), Fluorescence polarization (FP) is a one of the measurement techniques to study molecular interactions. We previously developed our own FP measurement system based on synchronization detection that uses a liquid crystal layer and an image sensor. The measurement cycle was fixed to 100 without any theoretical considerations, however, the influence of the synchrony and measurement cycles for FP values should be considered. In the present paper, we carried out an experimental and theoretical investigation into the influence of the synchrony between liquid crystal operation and image sampling for FP values of our system. When there was synchronization mismatch, the experimental FP values obtained using fluorescein ethylene glycol solution and the theoretical FP values changed according to the number of measurement cycles. Additionally, we measured the FP immunoassay for a physiologically active substance under synchronization mismatch. The synchronization mismatch influenced the measurement performance of the system, indicating that optimization of the number of image samplings was necessary to improve the measurement performance. For instance, the Mismatch 0.99 case, the measurement cycle should be 50 cycle judging from its dynamic range and R-square (R-2). From the investigation, we obtained theoretical and experimental knowledge on FP response to facilitate further applications of our FP system.
  • Understanding structure-activity relationships of pH-sensitive cationic lipids facilitates the rational identification of promising lipid nanoparticles for delivering siRNAs in vivo.
    Yusuke Sato, Kazuki Hashiba, Kosuke Sasaki, Masatoshi Maeki, Manabu Tokeshi, Hideyoshi Harashima
    Journal of controlled release, 295, 140, 152, 2019年02月10日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Lipid nanoparticles (LNPs) are one of the more promising technologies for efficiently delivering short interfering RNA (siRNA) in vivo. A pH-sensitive cationic lipid that facilitates the targeting of hepatocytes and endosomal escape, strongly influences the availability of siRNA, thus making it a key material for efficient siRNA delivery. A systematic knowledge regarding lipid structure-activity relationships would greatly facilitate the development of sophisticated pH-sensitive cationic lipids for use in siRNA-based therapeutics. The systemic derivatization of a hydrophilic head group and hydrophobic tails of YSK12-C4, a pH-sensitive cationic lipid that was developed in our laboratory, revealed that hydrophilic head significantly affected the apparent pKa of the final product, a key factor in both intrahepatic distribution and endosomal escape. The clogP value of a hydrophilic head group was found to be associated with the apparent pKa of the product. In contrast, the hydrophobic tail structure strongly affected intrahepatic distribution without depending on apparent pKa. A structure-activity relationship study enabled the selection of an adequate combination of a hydrophilic head group and hydrophobic tails and permitted a potent LNP composed of a pH-sensitive cationic lipid CL4H6 (CL4H6-LNPs) to be developed that showed efficient gene silencing activity (50% effective dose: 0.0025 mg/kg), biodegradability and was tolerated. In vivo experiments revealed that the CL4H6-LNPs showed a superior efficiency for endosomal escape, cytosolic release and the RNA-induced silencing for the complex-loading of siRNAs compared to the previously developed LNPs.
  • Development of a Microdevice for Facile Analysis of Theophylline in Whole Blood by a Cloned Enzyme Donor Immunoassay               
    Keine Nishiyama, Kanako Sugimura, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Lab on a Chip, 19, 233, 240, 2019年02月, [査読有り], [責任著者]
    英語, 研究論文(学術雑誌)
  • Micro total analysis system for determination of lithium ion in human whole blood with hybrid device of dmf and tiny paper sensors               
    Takeshi Komatsu, Manabu Tokeshi, Shih-Kang Fan
    23rd International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2019, 84, 85, Chemical and Biological Microsystems Society, 2019年
    英語, 研究論文(国際会議プロシーディングス), We improve the plasma separation with dielectrophoresis (DEP) [1,2] and demonstrate (1) separation of pure plasma droplets with a precise volume from human whole blood by electrowetting (EWOD) and DEP on a digital microfluidic (DMF) platform and (2) the measurement of lithium ion (Li+) concentration with integrated colorimetric paper sensors to achieve a practical total analysis system for human whole blood diagnosis.
  • Label-Free Electrochemical Sensor for Ochratoxin A Uisng a Microfabricated Electrode with Immobilized Aptamer
    Donny N. Mazaafrianto, Akihiko Ishida, Masatoshi Maeki, Hirofumi Tani, Manabu Tokeshi
    ACS Omega, 3, 12, 16823, 16830, American Chemical Society (ACS), 2018年12月, [査読有り], [最終著者, 責任著者]
    英語, 研究論文(学術雑誌)
  • Development of the immuno-wall device for rapid detection of ALK and ROS1 fusions in lung cancer               
    Yogo N, Hase T, Kasama T, Hatta T, Ozawa N, Sato M, Kaji N, Tokeshi M, Baba Y, Hasegawa Y
    ANNALS OF ONCOLOGY, 29, ., 2018年11月
    英語, 研究論文(学術雑誌)
  • 血中ATPと乳酸を指標とする重症度診断のための電気化学酵素センサーの開発               
    水上 良平, 真栄城 正寿, 石田 晃彦, 谷 博文, 渡慶次 学
    日本分析化学会講演要旨集, 67年会, 287, 287, (公社)日本分析化学会, 2018年08月
    日本語
  • Development of the iLiNP Device: Fine Tuning the Lipid Nanoparticle Size within 10 nm for Drug Delivery
    Niko Kimura, Masatoshi Maeki, Yusuke Sato, Yusuke Note, Akihiko Ishida, Hirofumi Tani, Hideyoshi Harashima, Manabu Tokeshi
    ACS Omega, 3, 5, 5044, 5051, American Chemical Society, 2018年05月09日, [査読有り], [最終著者, 責任著者]
    英語, 研究論文(学術雑誌), The precise size control of the lipid nanoparticle (LNP)-based nanodrug delivery system (DDS) carriers, such as 10 nm size tuning of LNPs, is one major challenge for the development of next-generation nanomedicines. Size-controlled LNPs would realize size-selective tumor targeting and deliver DNA and RNA to target tumor tissues effectively by passing through the stromal cells. Herein, we developed a baffle mixer device named the invasive lipid nanoparticle production device, or iLiNP device for short, which has a simple two-dimensional microchannel and mixer structure, and we achieved the first reported LNP size tuning at 10 nm intervals in the size range from 20 to 100 nm. In comparison with the conventional LNP preparation methods and reported micromixer devices, our iLiNP device showed better LNP size controllability, robustness of device design, and LNP productivity. Furthermore, we prepared 80 nm sized LNPs with encapsulated small interfering RNA (siRNA) using the iLiNP device
    these LNPs effectively performed as nano-DDS carriers in an in vivo experiment. We expect iLiNP devices will become novel apparatuses for LNP production in nano-DDS applications.
  • 微小化脂質ナノ粒子によるアジュバントのリンパ節送達               
    中村 孝司, 河合 美典, 佐藤 悠介, 真栄城 正寿, 渡慶次 学, 原島 秀吉
    日本薬剤学会年会講演要旨集, 33年会, 193, 193, (公社)日本薬剤学会, 2018年05月
    日本語
  • Recent Microdevice-based Aptamer Sensors
    Manabu Tokeshi
    Micromachines, 9, 1, 25, 2018年04月, [査読有り], [招待有り], [最終著者, 責任著者]
    英語, 研究論文(学術雑誌)
  • Microfluidic Devices for Drug Delivery Systems
    Manabu Tokeshi
    Advanced Drug Delivery Reviews, 128, 1, 2, Elsevier B.V., 2018年03月15日, [査読有り], [招待有り], [責任著者]
    英語, 研究論文(学術雑誌)
  • Advances in microfluidics for lipid nanoparticles and extracellular vesicles and applications in drug delivery systems
    Masatoshi Maeki, Niko Kimura, Yusuke Sato, Hideyoshi Harashima, Manabu Tokeshi
    Advanced Drug Delivery Reviews, 128, 84, 100, Elsevier B.V., 2018年03月15日, [査読有り], [招待有り], [最終著者, 責任著者]
    英語, Lipid-based nanobiomaterials as liposomes and lipid nanoparticles (LNPs) are the most widely used nanocarriers for drug delivery systems (DDSs). Extracellular vesicles (EVs) and exosomes are also expected to be applied as DDS nanocarriers. The performance of nanomedicines relies on their components such as lipids, targeting ligands, encapsulated DNA, encapsulated RNA, and drugs. Recently, the importance of the nanocarrier sizes smaller than 100 nm is attracting attention as a means to improve nanomedicine performance. Microfluidics and lab-on-a chip technologies make it possible to produce size-controlled LNPs by a simple continuous flow process and to separate EVs from blood samples by using a surface marker, ligand, or electric charge or by making a mass or particle size discrimination. Here, we overview recent advances in microfluidic devices and techniques for liposomes, LNPs, and EVs and their applications for DDSs.
  • がん組織における浸潤性向上を目指した極小脂質ナノ粒子の開発               
    岡部 奈々, 佐藤 悠介, 真栄城 正寿, 渡慶次 学, 原島 秀吉
    日本薬学会年会要旨集, 138年会, 4, 78, 78, (公社)日本薬学会, 2018年03月
    日本語
  • A compact fluorescence polarization analyzer with high-transmittance liquid crystal layer
    Osamu Wakao, Ken Satou, Ayano Nakamura, Ken Sumiyoshi, Masanori Shirokawa, Chikaaki Mizokuchi, Kunihiro Shiota, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Koji Shigemura, Akihide Hibara, Manabu Tokeshi
    Review of Scientific Instruments, 89, 2, 024103, American Institute of Physics Inc., 2018年02月01日, [査読有り], [最終著者, 責任著者]
    英語, 研究論文(学術雑誌), Fluorescence polarization (FP) offers easy operation and rapid processing, making it implementable in molecular interaction analysis. Previously we have developed a unique FP measurement system using a liquid crystal (LC) layer and an image sensor. The system is based on a principle of synchronized detection between the switching rate of the LC layer and the sampling rate of the CCD. The FP system realized simultaneous multiple sample detection
    however, the measurement precision was lower than that of the conventional FP apparatus. The main drawbacks were low light transmittance of the LC layer and insufficient synchronization between the LC layer and CCD. In this paper, we developed a new FP analyzer based on LC-CCD synchronization detection. By using a newly designed LC with high transmittance and improving synchronization, the performance of the system has been dramatically improved. Additionally, we reduced the cost by using an inexpensive CCD and an LED as the excitation source. Simultaneous FP immunoassay of multiple samples of prostaglandin E2 was performed. The error rate of the FP system is reduced from 16.9% to 3.9%, as comparable to the commercial conventional FP system.
  • Microfabrication and microfluidic devices for drug delivery
    Niko Kimura, Masatoshi Maeki, Manabu Tokeshi
    Microfluidics for Pharmaceutical Applications: From Nano/Micro Systems Fabrication to Controlled Drug Delivery, 123, 136, 2018年01月01日
    論文集(書籍)内論文, Carrier-assist drug delivery systems (DDSs) have been developed to improve the present problems of the cancer chemotherapies. In the developed several types of DDS carriers, lipid nanoparticles (LNPs) are the most widely used for the cancer chemotherapy. Although LNPs have high biocompatibility and good circulation time in blood, precise size control of LNPs in the size range of 20-100 nm is required for the cancer therapy applications. Microfluidic devices will be key apparatus to achieve the size-controlled LNP synthesis. A microfluidic device with micromixer structures also plays important role for the LNP production, because it enables rapid mixing of lipid solution and aqueous solution for precise LNP size control. This chapter provides the microfluidic-based LNP production methods from the device fabrication to DDS applications.
  • A post-treatment methodology for precise size control of lipid nanoparticles by stepwise and rapid ethanol dilution
    Niko Kimura, Masatoshi Maeki, Nana Okabe, Yusuke Sato, Akihiko Ishida, Hirofumi Tani, Hideyoshi Harashima, Manabu Tokeshi
    22nd International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2018, 3, 1404, 1405, 2018年
    研究論文(国際会議プロシーディングス), This paper reports a methodology for precise controlling the lipid nanoparticle (LNP) size by stepwise and rapid ethanol dilution using an integrated microfluidic device with baffle mixers. The integrated microfluidic device coupling the LNP synthesis and the post-treatment regions had better size controllability of LNPs than the conventional preparation methods. Additionally, 30 nm-sized siRNA-loaded LNPs prepared by the post-treatment process using the integrated microfluidic device showed great gene-silencing activity and specific intrahepatic biodistribution. The stepwise and rapid ethanol dilution methodology using the integrated microfluidic device provides LNPs with homogeneous size distribution for improving the efficacy of nanomedicines.
  • Characteristics of microfluidic paper-based analytical devices fabricated by four different methods
    Takeshi Komatsu, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Analytical Sciences, 34, 1, 39, 44, Japan Society for Analytical Chemistry, 2018年, [査読有り], [最終著者, 責任著者]
    英語, 研究論文(学術雑誌), We report on the effects of fabrication methods, photolithography, wax printing, screen printing, and craft cutting, on selected properties of microfluidic paper-based analytical devices (μPADs): cost, fabrication precision, wicking rate, and analytical accuracy. Photolithography requires numerous fabrication steps, and an oxygen plasma treatment is necessary when using an aqueous solution. Although the boundary between the hydrophobic and hydrophilic areas in the μPAD is sharpest, the obtained K-scale intensity in measuring of protein concentrations is lower than those of the devices by other methods. Wax printing offers the simplest and fastest fabrication, although solution leakage measures should be taken to improve the wicking rate and to prevent cross-contamination. Screen printing also offers easy fabrication. The screenprinted μPAD has a good wicking performance and shows a high detection intensity. Craft cutting allows automated fabrication of many μPADs at once. The craft cut μPAD has the fastest wicking rate among the four μPADs due to bare cellulose fibers. We consider that the detection intensity of this μPAD can be raised by optimizing the evaporation rate.
  • Dynamic wettability of polyethylene glycol-modified poly(dimethylsiloxane) surfaces in an aqueous/organic two-phase system
    Mao Fukuyama, Manabu Tokeshi, Mikhail A. Proskurnin, Akihide Hibara
    Lab on a Chip, 18, 2, 356, 361, Royal Society of Chemistry, 2018年, [査読有り], [国際共著]
    英語, 研究論文(学術雑誌), We herein report the preparation of a surface that behaves in a hydrophobic manner but does not undergo protein adsorption in an aqueous/organic two-phase system. We found that polyethylene-glycol (PEG)-modified poly(dimethylsiloxane) (PDMS) exhibits hydrophobic properties when the surface is immersed in an organic solution, while the PEG moiety prevents protein adsorption on the PDMS surface in an aqueous solution at high protein concentrations due to the dynamic behaviour of the PEG moiety. As such, we demonstrated the in-well droplet formation of an aqueous solution containing a high protein concentration. In addition, to demonstrate the feasibility of this method in single cell analyses, a droplet array of a liquid medium containing 10% fetal bovine serum and HeLa cells was formed. The preparation of a droplet array using our PDMS-PEG surface to promote in-well droplet formation avoided the use of flow control equipment and complicated microstructures. We therefore expect that the dynamic wettability of our reported surface will be applicable in single cell and biochemical analyses, such as protein characterisation using crystallography or immunoassays.
  • マイクロデバイスを用いたタンパク質の立体構造解析
    真栄城 正寿, 宮崎 真佐也, 渡慶次 学
    ぶんせき, 516, 575, 580, (公社)日本分析化学会, 2017年12月
    日本語
  • Development of the immuno-wall device for rapid, low-cost detection of EGFR mutations in tumor samples from patients with lung cancer               
    Yogo N, Hase T, Kasama T, Ozawa N, Sato M, Kaji N, Tokeshi M, Baba Y, Hasegawa Y
    ANNALS OF ONCOLOGY, 28, ., 2017年11月
    英語, 研究論文(学術雑誌)
  • Understanding the formation mechanism of lipid nanoparticles in microfluidic devices with chaotic micromixers
    Masatoshi Maeki, Yuka Fujishima, Yusuke Sato, Takao Yasui, Noritada Kaji, Akihiko Ishida, Hirofumi Tani, Yoshinobu Baba, Hideyoshi Harashima, Manabu Tokeshi
    PLoS ONE, 12, 11, e0187962, 2017年11月, [査読有り], [責任著者]
    英語, 研究論文(学術雑誌), © 2017 Maeki et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Lipid nanoparticles (LNPs) or liposomes are the most widely used drug carriers for nanomedicines. The size of LNPs is one of the essential factors affecting drug delivery efficiency and therapeutic efficiency. Here, we demonstrated the effect of lipid concentration and mixing performance on the LNP size using microfluidic devices with the aim of understanding the LNP formation mechanism and controlling the LNP size precisely. We fabricated microfluidic devices with different depths, 11 μm and 31 μm, of their chaotic micromixer structures. According to the LNP formation behavior results, by using a low concentration of the lipid solution and the microfluidic device equipped with the 31 μm chaotic mixer structures, we were able to produce the smallest-sized LNPs yet with a narrow particle size distribution. We also evaluated the mixing rate of the microfluidic devices using a laser scanning confocal microscopy and we estimated the critical ethanol concentration for controlling the LNP size. The critical ethanol concentration range was estimated to be 60–80% ethanol. Ten nanometer-sized tuning of LNPs was achieved for the optimum residence time at the critical concentration using the microfluidic devices with chaotic mixer structures. The residence times at the critical concentration necessary to control the LNP size were 10, 15–25, and 50 ms time-scales for 30, 40, and 50 nm-sized LNPs, respectively. Finally, we proposed the LNP formation mechanism based on the determined LNP formation behavior and the critical ethanol concentration. The precise size-controlled LNPs produced by the microfluidic devices are expected to become carriers for next generation nanomedicines and they will lead to new and effective approaches for cancer treatment.
  • Using Laser Interference Lithography in the Fabrication of a Simplified Micro and Nanofluidic Device for Label-free Detection
    Taiga Ajiri, Haruya Kasa, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Junji Nishi, Manabu Tokeshi
    Analytical Sciences, 33, 10, 1197, 1199, JAPAN SOC ANALYTICAL CHEMISTRY, 2017年10月, [査読有り], [責任著者]
    英語, 研究論文(学術雑誌), Recently, we developed a label-free detection method based on optical diffraction, and implemented it in on our fabricated micro- and nanofluidic device. This detection method is simple and useful for detecting biomolecules, but the device fabrication consists of complicated processes. In this paper, we propose a simple method for fabricating the micro- and nanofluidic device; the fabrication combines laser interference lithography with conventional photolithography. The performance of a device fabricated by the proposed method is comparable to the performance of the device in our previous study.
  • Optimization of the nanofluidic design for label-free detection of biomolecules using a nanowall array
    Taiga Ajiri, Takao Yasui, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Yoshinobu Baba, Manabu Tokeshi
    Sensors and Actuators B-Chemical, 250, 39, 43, ELSEVIER SCIENCE SA, 2017年10月, [査読有り], [責任著者]
    英語, 研究論文(学術雑誌), Single-molecule detection of the biomolecules in a label-free manner has a tremendous impact for various fields. Recently, we developed a label-free detection method without any pretreatment procedures, which is based on optical diffraction derived from a nanofluidic channel array (in other words, a nanowall array). However, the single-molecule detection is hampered by the inherent sensitivity of the method. We propose a solution to improve the sensitivity of the method by adjusting the height of the nanowall array. Numerical simulations showed that a larger nanowall array height could provide better sensitivity, but a lower nanowall array height could provide better sensitivity difference, contrary to what we would intuitively expect. We used a 250 nm height nanowall array to achieve a label-free detection of 0.18 DNA molecules to verify the simulation prediction. These results demonstrate our method has a potential to be implemented in a highly sensitive refractometer with small sample consumption. (C) 2017 Elsevier B.V. All rights reserved.
  • 尿中シュウ酸分析のための単一くし形電極を組み込んだ液体クロマトグラフィーチップの開発               
    藤井 大地, 真栄城 正寿, 石田 晃彦, 谷 博文, 渡慶次 学
    日本分析化学会講演要旨集, 66年会, 24, 24, (公社)日本分析化学会, 2017年08月
    日本語
  • マイクロ流体デバイスを用いた化学発光イムノアッセイの高感度化               
    菊地 優仁, 真栄城 正寿, 石田 晃彦, 谷 博文, 渡慶次 学
    日本分析化学会講演要旨集, 66年会, 52, 52, (公社)日本分析化学会, 2017年08月
    日本語
  • 血中ATPと乳酸測定のための電気化学センサーの開発               
    水上 良平, 西山 慶音, 真栄城 正寿, 石田 晃彦, 谷 博文, 渡慶次 学
    日本分析化学会講演要旨集, 66年会, 134, 134, (公社)日本分析化学会, 2017年08月
    日本語
  • A millisecond micro-RNA separation technique by a hybrid structure of nanopillars and nanoslits
    Qiong Wu, Noritada Kaji, Takao Yasui, Sakon Rahong, Takeshi Yanagida, Masaki Kanai, Kazuki Nagashima, Manabu Tokeshi, Tomoji Kawai, Yoshinobu Baba
    Scientific Reports, 7, 43877, NATURE PUBLISHING GROUP, 2017年03月, [査読有り]
    英語, 研究論文(学術雑誌), A millisecond micro-RNA separation of a mixture of total RNA and genomic DNA, extracted from cultured HeLa cells, was successfully achieved using a hybrid structure of nanopillars and nanoslits contained inside a microchannel. The nanopillars, 250-nm in diameter and 100-nm in height, were fabricated with a 750-nm space inside the nanoslits, which were 100-nm in height and 25-mu m in width; the nanopillars were then applied as a new sieve matrix. This ultra-fast technique for the separation of miRNA can be an effective pretreatment for semiconductor nanopore DNA sequencing, which has an optimum reading speed of 1 base/ms to obtain effective signal-to-noise ratio and discriminate each base by ion or tunneling current during the passage of nucleic acids.
  • Fabrication and Evaluation of Microfluidic Immunoassay Devices with Antibody-Immobilized Microbeads Retained in Porous Hydrogel Micropillars
    Kasama Toshihiro, Kaji Noritada, Tokeshi Manabu, Baba Yoshinobu
    MICROCHIP DIAGNOSTICS: METHODS AND PROTOCOLS, 1547, 49, 56, 2017年, [国際誌]
    英語, 論文集(書籍)内論文, © Springer Science+Business Media LLC 2017. Due to the inherent characteristics including confinement of molecular diffusion and high surface-to-volume ratio, microfluidic device-based immunoassay has great advantages in cost, speed, sensitivity, and so on, compared with conventional techniques such as microtiter plate-based ELISA, latex agglutination method, and lateral flow immunochromatography. In this paper, we explain the detection of C-reactive protein as a model antigen by using our microfluidic immunoassay device, so-called immuno-pillar device. We describe in detail how we fabricated and used the immuno-pillar devices.
  • Rapid Detection of Cat Cystatin C (cCys-C) Using Immuno-Pillar Chips
    Saeed Mohammadi, Lori Shayne Alamo Busa, Masatoshi Maeki, Reza M. Mohamadi, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Analytical Sciences, 32, 12, 1359, 1362, JAPAN SOC ANALYTICAL CHEMISTRY, 2016年12月, [査読有り]
    英語, 研究論文(学術雑誌), We demonstrated a rapid immunoassay for detection of cat cystatin C (cCys-C) which is an important marker for chronic kidney disease in cats, using immuno-pillar chips. The required amount of reagent solution is 200 times smaller than that for the conventional ELISA in the 96-well microplate (0.5 mu L versus 100 mu L). In addition, the total assay time in the proposed method is more than 12 times shorter than in the conventional method (20 min versus 240 min). The limit of detection in the new method of 3 ng mL(-1) is comparable to that of the conventional method (1 ng mL(-1)) and it is in the clinically relevant range.
  • Novel concept of washing for microfluidic paper-based analytical devices based on capillary force of paper substrates
    Saeed Mohammadi, Lori Shayne Alamo Busa, Masatoshi Maeki, Reza M. Mohamadi, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Analytical and Bioanalytical Chemistry, 408, 27, 7559, 7563, SPRINGER HEIDELBERG, 2016年11月, [査読有り]
    英語, 研究論文(学術雑誌), A novel washing technique for microfluidic paper-based analytical devices (mu PADs) that is based on the spontaneous capillary action of paper and eliminates unbound antigen and antibody in a sandwich immunoassay is reported. Liquids can flow through a porous medium (such as paper) in the absence of external pressure as a result of capillary action. Uniform results were achieved when washing a paper substrate in a PDMS holder which was integrated with a cartridge absorber acting as a porous medium. Our study demonstrated that applying this washing technique would allow mu PADs to become the least expensive microfluidic device platform with high reproducibility and sensitivity. In a model mu PAD assay that utilized this novel washing technique, C-reactive protein (CRP) was detected with a limit of detection (LOD) of 5 mu g mL(-1).
  • Simple and sensitive colorimetric assay system for horseradish peroxidase using microfluidic paper-based devices
    Lori Shayne Alamo Busa, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Sensors and Actuators B-Chemical, 236, 433, 441, ELSEVIER SCIENCE SA, 2016年11月
    英語, 研究論文(学術雑誌), This article describes the development of a simple, portable assay system using microfluidic paper-based analytical devices (mu PADs) coupled with colorimetric detection for rapid measurements. The properties of different paper substrates were first investigated to determine which type of paper would be the most suitable for the fabrication of the mu PADs. Simultaneous detection of horseradish peroxidase (HRP) utilizing a 5 mu L sample analytical volume was demonstrated using a single mu PAD. Hydrophilic test regions were separated by hydrophobic barriers, which were fabricated through photolithography. These test regions were immobilized with 10 mM of 3,3',5,5'-tetramethylbenzidine for HRP assay. The detection range obtained with the proposed system covered HRP concentrations from 0.37 to 124 fmol (or 31000 ng mL(-1)). The detection limit (blank + 3 sigma) for HRP was calculated to be 0.69 fmol (or 5.58 ng mL(-1)) through a 4-parameter logistic nonlinear regression using results obtained within a 15 min assay time. The findings obtained using the developed system suggest that mu PAD assay systems for simple but highly sensitive measurements can be designed to give on-site determinations of target compounds using peroxidase-conjugated molecules. ((c)) 2016 Elsevier B.V. All rights reserved.
  • 血中リチウム濃度測定のためのペーパーデバイスの開発               
    小松 雄士, 真栄城 正寿, 石田 晃彦, 谷 博文, 渡慶次 学
    日本分析化学会講演要旨集, 65年会, 163, 163, (公社)日本分析化学会, 2016年08月
    日本語
  • Label-free detection of real-time DNA amplification using a nanofluidic diffraction grating
    Takao Yasui, Kensuke Ogawa, Noritada Kaji, Mats Nilsson, Taiga Ajiri, Manabu Tokeshi, Yasuhiro Horiike, Yoshinobu Baba
    Scientific Reports, 6, 31642, NATURE PUBLISHING GROUP, 2016年08月, [査読有り]
    英語, 研究論文(学術雑誌), Quantitative DNA amplification using fluorescence labeling has played an important role in the recent, rapid progress of basic medical and molecular biological research. Here we report a label-free detection of real-time DNA amplification using a nanofluidic diffraction grating. Our detection system observed intensity changes during DNA amplification of diffracted light derived from the passage of a laser beam through nanochannels embedded in a microchannel. Numerical simulations revealed that the diffracted light intensity change in the nanofluidic diffraction grating was attributed to the change of refractive index. We showed the first case reported to date for label-free detection of real-time DNA amplification, such as specific DNA sequences from tubercle bacilli (TB) and human papillomavirus (HPV). Since our developed system allows quantification of the initial concentration of amplified DNA molecules ranging from 1 fM to 1 pM, we expect that it will offer a new strategy for developing fundamental techniques of medical applications.
  • 3,3’,5,5’-Tetramethylbenzidine Oxidation on Paper Devices for Horseradish Peroxidase-Based Assays
    Lori Shayne, Almo Busa, Takeshi Komatsu, Saeed Mohammadi, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Analytical Science, 32, 8, 815, 818, JAPAN SOC ANALYTICAL CHEMISTRY, 2016年08月, [査読有り]
    英語, 研究論文(学術雑誌), We report on the colorimetric oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by hydrogen peroxide using horseradish peroxidase on photolithography-fabricated (P-PAD) and wax-printed (W-PAD) paper-based analytical devices. Fabricating PADs via photolithography exposes the hydrophilic areas to polymers (photoresists) and solvents, not only reducing the hydrophilicity, but also affecting the TMB-H2O2 assay system with an unavoidable incomplete elimination of photoresist during fabrication. Detection signals are then observed in the presence of photoresist residues on the P-PAD, even at a blank HRP concentration.
  • Microfluidic Autologous Serum Eye-Drops Preparation as a Potential Dry Eye Treatment
    Takao Yasui, Jumpei Morikawa, Noritada Kaji, Manabu Tokeshi, Kazuo Tsubota, Yoshinobu Baba
    Micromachines, 7, 7, 113, MDPI AG, 2016年07月, [査読有り]
    英語, 研究論文(学術雑誌), Dry eye is a problem in tearing quality and/or quantity and it afflicts millions of persons worldwide. An autologous serum eye-drop is a good candidate for dry eye treatment; however, the eye-drop preparation procedures take a long time and are relatively troublesome. Here we use spiral microchannels to demonstrate a strategy for the preparation of autologous serum eye-drops, which provide benefits for all dry eye patients; 100% and 90% removal efficiencies are achieved for 10 mu m microbeads and whole human blood cells, respectively. Since our strategy allows researchers to integrate other functional microchannels into one device, such a microfluidic device will be able to offer a new one-step preparation system for autologous serum eye-drops.
  • Elucidation of the physicochemical properties and potency of siRNA-loaded small-sized lipid nanoparticles for siRNA delivery
    Yusuke Sato, Yusuke Note, Masatoshi Maeki, Noritada Kaji, Yoshinobu Baba, Manabu Tokeshi, Hideyoshi Harashima
    Journal of Controlled Release, 229, 48, 57, ELSEVIER SCIENCE BV, 2016年05月, [査読有り]
    英語, 研究論文(学術雑誌), Because nanoparticles with diameters less than 50 nm penetrate stromal-rich tumor tissues more efficiently, the synthesis of small-sized nanoparticles encapsulating short interfering RNA (siRNA) is important in terms of realizing novel siRNA medicine for the treatment of various cancers. Lipid nanoparticles (LNPs) are the leading systems for the delivery of siRNA in vivo. Limit size LNPs were successfully synthesized using a microfluidic mixing technique. However, the physicochemical properties and potential for in vivo siRNA delivery of the limit-size LNPs have not been examined in detail. In the present study, we prepared LNPs with different diameters from 32 to 67 nm using a microfluidic mixing devise and examined the physicochemical properties of the particles and the potential for their use in delivering siRNA in vitro and in vivo to liver. Reducing the size of the LNPs causes poor-packing and an increased surface area, which result in their instability in serum. Moreover, it was revealed that the ability of endosomal escape (cytosolic siRNA release) of the smaller LNPs is subject to inhibition by serum compared to that of larger counterparts. Taken together, an increase in packing and avoiding the adsorption of serum components are key strategies for the development of next-generation highly potent and small-sized LNPs. (C) 2016 Elsevier B.V. All rights reserved.
  • An Easy-to-Use Polystyrene Microchip-based Cell Culture System
    Hidekatsu Tazawa, Shohei Sunaoshi, Manabu Tokeshi, Takehiko Kitamori, Ritsuko Ohtani-Kaneko
    Analytical Sciences, 32, 3, 349, 353, JAPAN SOC ANALYTICAL CHEMISTRY, 2016年03月, [査読有り]
    英語, 研究論文(学術雑誌), In this study, we developed an integrated, low-cost microfluidic cell culture system that is easy to use. This system consists of a disposable polystyrene microchip, a polytetrafluoroethylene valve, an air bubble trap, and an indium tin oxide temperature controller. Valve pressure resistance was validated with a manometer to be 3 MPa. The trap protected against bubble contamination. The temperature controller enabled the culture of Macaca mulatta RF/6A 135 vascular endothelial cells, which are difficult to culture in glass microchips, without a CO2 incubator. We determined the optimal coating conditions for these cells and were able to achieve stable, confluent culture within 1 week. This practical system is suitable for low-cost screening and has potential applications as circulatory cell culture systems and research platforms in cell biology.
  • 脂質ナノ粒子の形成と形成メカニズムの解明
    渡慶次 学
    ホソカワ粉体工学振興財団年報, 24, 74, 78, 公益財団法人 ホソカワ粉体工学振興財団, 2016年
    日本語,

    マイクロ流体デバイスによる脂質ナノ粒子の作製法は,従来法と比較すると,粒子サイズと粒径分布の制御,簡便,作製時間など多くの利点を持っている.しかし,流路内で形成される粒子の形成メカニズムが明らかになっていない.脂質ナノ粒子の形成メカニズムを解明することにより,粒子サイズおよび粒径分布を精密に制御できるようになることが期待される.本研究では,マイクロミキサーを組み込んだマイクロ流体デバイスを作製し,原料溶液(脂質/エタノール溶液と生理食塩水)の混合状態の観察および作製された脂質ナノ粒子の粒径および粒径分布の測定を行った.これらの結果より,マイクロ流路内で作製される脂質ナノ粒子の形成には,溶液同士の完全混合よりも,エタノールを一定の濃度まで急激に希釈することが重要であることを明らかにした.

  • Microfluidic Autologous Serum Eye-Drops Preparation as a Potential Dry Eye Treatment.
    Takao Yasui, Jumpei Morikawa, Noritada Kaji, Manabu Tokeshi, Kazuo Tsubota, Yoshinobu Baba
    Micromachines, 7, 7, 113, 113, 2016年, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Dry eye is a problem in tearing quality and/or quantity and it afflicts millions of persons worldwide. An autologous serum eye-drop is a good candidate for dry eye treatment; however, the eye-drop preparation procedures take a long time and are relatively troublesome. Here we use spiral microchannels to demonstrate a strategy for the preparation of autologous serum eye-drops, which provide benefits for all dry eye patients; 100% and 90% removal efficiencies are achieved for 10 μm microbeads and whole human blood cells, respectively. Since our strategy allows researchers to integrate other functional microchannels into one device, such a microfluidic device will be able to offer a new one-step preparation system for autologous serum eye-drops.
  • Advances in microfluidic paper-based analytical devices for food and water analysis
    Lori Shayne Alamo Busa, Saeed Mohammadi, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Micromachines, 7, 5, 1, 21, MDPI AG, 2016年, [査読有り]
    英語, 研究論文(学術雑誌), Food and water contamination cause safety and health concerns to both animals and humans. Conventional methods for monitoring food and water contamination are often laborious and require highly skilled technicians to perform the measurements, making the quest for developing simpler and cost-effective techniques for rapid monitoring incessant. Since the pioneering works of Whitesides' group from 2007, interest has been strong in the development and application of microfluidic paper-based analytical devices (μPADs) for food and water analysis, which allow easy, rapid and cost-effective point-of-need screening of the targets. This paper reviews recently reported μPADs that incorporate different detection methods such as colorimetric, electrochemical, fluorescence, chemiluminescence, and electrochemiluminescence techniques for food and water analysis.
  • Microfluidic approaches for protein crystal structure analysis
    Masatoshi Maeki, Hiroshi Yamaguchi, Manabu Tokeshi, Masaya Miyazaki
    Analytical Sciences, 32, 1, 3, 9, Japan Society for Analytical Chemistry, 2016年, [査読有り]
    英語, 研究論文(学術雑誌), This review summarizes two microfluidic-based protein crystallization methods, protein crystallization behavior in the microfluidic devices, and their applications for X-ray crystal structure analysis. Microfluidic devices provide many advantages for protein crystallography
    they require small sample volumes, provide high-throughput screening, and allow control of the protein crystallization. A droplet-based protein crystallization method is a useful technique for high-throughput screening and the formation of a single crystal without any complicated device fabrication process. Well-based microfluidic platforms also enable effective protein crystallization. This review also summarizes the protein crystal growth behavior in microfluidic devices as, is known from viewpoints of theoretical and experimental approaches. Finally, we introduce applications of microfluidic devices for on-chip crystal structure analysis.
  • A competitive immunoassay system for microfluidic paper-based analytical detection of small size molecules
    Lori Shayne Alamo Busa, Saeed Mohammadi, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Analyst, 141, 24, 6598, 6603, ROYAL SOC CHEMISTRY, 2016年, [査読有り]
    英語, 研究論文(学術雑誌), The development of a competitive immunoassay system for colorimetric detection on microfluidic paper-based analytical devices (mu PADs) is reported. The mu PADs were fabricated via photolithography to define hydrophilic flow channels and consisted of three main elements: the control and test zones, where target detection was performed, the sample introduction zone, and the competitive capture zone located between the sample introduction zone and the test zone. The chromogenic substrate 3,3', 5,5'-tetra-methylbenzidine (TMB) was deposited at the control and test zones. mu PAD surface modification was performed at the capture zone first via chitosan activation, then the BSA-conjugated target compound was immobilized. The sample solution consisting of the target compound, the peroxidase-conjugated antibody, and the hydrogen peroxide oxidizing agent was introduced into the device and competition occurred at the capture zone, allowing only the target-bound peroxidase-conjugated antibody to travel past the capture zone and into the test zone via capillary action. The developed competitive immunoassay system was successfully demonstrated on the mu PAD detection of biotin as a model compound with a detection limit of 0.10 mu g mL(-1). The applicability of the proposed immunoassay system for point-of-need testing was further demonstrated using aflatoxin B-1, a highly toxic foodborne substance, with a detection limit of 1.31 ng mL(-1). The mu PAD with the competitive immunoassay format showed promising results for practical applications in point-of-need testing involving small molecular weight targets in food and water safety and quality monitoring, environmental analysis, and clinical diagnostics.
  • Image analysis for a microfluidic paper-based analytical device using the CIE L(star)a(star)b(star) color system
    Takeshi Komatsu, Saeed Mohammadi, Lori Shayne Alamo Busa, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Analyst, 141, 24, 6507, 6509, ROYAL SOC CHEMISTRY, 2016年, [査読有り]
    英語, 研究論文(学術雑誌), The combination of a microfluidic paper-based analytical device (mu PAD) and digital image analysis is widely used for quantitative analysis with mu PADs because of its easy and simple operation. Herein, we have demonstrated a quantitative analysis based on multiple color changes on a mu PAD. The CIE L*a*b* color system was employed to analyse the digital images obtained with the mu PAD. We made pH measurements using a universal pH-indicator showing multiple color changes for various pH values of aqueous test solutions. The detectable pH range of this method was wider than the typical grayscale-based image analysis, and we succeeded in the measurements for a wide pH range of 2-9.
  • A microfluidic-based protein crystallization method in 10 micrometer-sized crystallization space
    Masatoshi Maeki, Shohei Yamazaki, Ashtamurthy S. Pawate, Akihiko Ishida, Hirofumi Tani, Kenichi Yamashita, Masakazu Sugishima, Keiichi Watanabe, Manabu Tokeshi, Paul J. A. Kenis, Masaya Miyazaki
    CrystEngComm, 18, 40, 7722, 7727, ROYAL SOC CHEMISTRY, 2016年, [査読有り]
    英語, 研究論文(学術雑誌), Protein crystallization and subsequent X-ray diffraction analysis of the three-dimensional structure are necessary for elucidation of the biological functions of proteins and effective rational drug design. Therefore, controlling protein crystallization is important to obtain high resolution X-ray diffraction data. Here, a simple microfluidic method using chips with 10 and 50 mu m high crystallization chambers to selectively form suitable single protein crystals for X-ray analysis is demonstrated. As proof of concept, three different types of proteins: lysozyme, glucokinase from Pseudoalteromonas sp. AS-131 (PsGK), and NADPH-cytochrome P450 oxidoreductase-heme oxygenase complex were crystallized. We demonstrate that the crystal growth orientation depends on the height of the crystallization chamber regardless of the protein type. Our results suggest that the confined micro space induces the protein molecules to adhere to a specific crystal face and affects the growth kinetics of each crystal face. The present microfluidic-based protein crystallization method can reform a suitable single protein crystal for X-ray analysis from aggregates of needle-shaped protein crystals.
  • An immuno-wall microdevice exhibits rapid and sensitive detection of IDH1-R132H mutation specific to grade II and III gliomas
    Akane Yamamichi, Toshihiro Kasama, Fumiharu Ohka, Hiromichi Suzuki, Akira Kato, Kazuya Motomura, Masaki Hirano, Melissa Ranjit, Lushun Chalise, Michihiro Kurimoto, Goro Kondo, Kosuke Aoki, Noritada Kaji, Manabu Tokeshi, Toshio Matsubara, Takeshi Senga, Mika K. Kaneko, Hidenori Suzuki, Masahito Hara, Toshihiko Wakabayashi, Yoshinobu Baba, Yukinari Kato, Atsushi Natsume
    Science and Technology of Advanced Materials, 17, 1, 618, 625, TAYLOR & FRANCIS LTD, 2016年, [査読有り]
    英語, 研究論文(学術雑誌), World Health Organization grade II and III gliomas most frequently occur in the central nervous system (CNS) in adults. Gliomas are not circumscribed; tumor edges are irregular and consist of tumor cells, normal brain tissue, and hyperplastic reactive glial cells. Therefore, the tumors are not fully resectable, resulting in recurrence, malignant progression, and eventual death. Approximately 69-80% of grade II and III gliomas harbor mutations in the isocitrate dehydrogenase 1 gene (IDH1), of which 83-90% are found to be the IDH1-R132H mutation. Detection of the IDH1-R132H mutation should help in the differential diagnosis of grade II and III gliomas from other types of CNS tumors and help determine the boundary between the tumor and normal brain tissue. In this study, we established a highly sensitive antibody-based device, referred to as the immuno-wall, to detect the IDH1-R132H mutation in gliomas. The immuno-wall causes an immunoreaction in microchannels fabricated using a photo-polymerizing polymer. This microdevice enables the analysis of the IDH1 status with a small sample within 15 min with substantially high sensitivity. Our results suggested that 10% content of the IDH1-R132H mutation in a sample of 0.33 mu l volume, with 500 ng protein, or from 500 cells is theoretically sufficient for the analysis. The immuno-wall device will enable the rapid and highly sensitive detection of the IDH1-R132H mutation in routine clinical practice.
  • A Portable Liquid Chromatograph with a Battery-operated Compact Electroosmotic Pump and a Microfluidic Chip Device with a Reversed Phase Packed Column
    Akihiko Ishida, Mitsutaka Fujii, Takehiro Fujimoto, Shunsuke Sasaki, Ichiro Yanagisawa, Hirofumi Tani, Manabu Tokeshi
    ANALYTICAL SCIENCES, 31, 11, 1163, 1169, JAPAN SOC ANALYTICAL CHEMISTRY, 2015年11月, [査読有り]
    英語, 研究論文(学術雑誌), A compact and lightweight liquid chromatography system is presented with overall dimensions of 26 cm width x 18 cm length x 21 cm height and weight of 2 kg. This system comprises a battery-operated compact electroosmotic pump, a manual injector, a microfluidic chip device containing a packed column and an electrochemical detector, and a USB bus-powered potentiostat. The pumping system was designed for microfluidic-based reversed-phase liquid chromatography in which an electroosmotically generated water stream pushes the mobile phase via a diaphragm for the output. The flow rate ranged from 0 to 10 mu L/min and had a high degree of precision. The pumping system operated continuously for over 24 h with dry batteries. The column formed in the microfluidic device was packed with 3-mu m ODS particles with a length of 30 mm and a diameter of 0.8 mm. The results presented herein demonstrate the performance of the pumping system and the column using alkylphenols, catecholamine, catechin, and amino acids.
  • Micropillars Fabricated on Poly(methyl methacrylate) Substrates for Separation of Microscale Objects
    Takao Yasui, Satoru Ito, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Analytical Sciences, 31, 11, 1197, 1200, JAPAN SOC ANALYTICAL CHEMISTRY, 2015年11月, [査読有り]
    英語, 研究論文(学術雑誌), Development of polymeric microfluidic devices has played an important role in the recent, rapid progress of biomedical research. Here we report a fabrication method for micropillars on poly(methyl methacrylate) (PMMA) substrates for separation of microscale objects. The fabricated micropillars enable continuous separation of microparticles only by introducing fluids. The present method offers a new strategy to fabricate polymeric prototype devices for R&D work.
  • Fluorescence Polarization Measurement System Using a Liquid Crystal Layer and an Image Sensor
    Osamu Wakao, Yusaku Fujii, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Akihide Hibara, Manabu Tokeshi
    Analytical Chemistry, 87, 19, 9647, 9652, AMER CHEMICAL SOC, 2015年10月, [査読有り]
    英語, 研究論文(学術雑誌), The detection system which enables simultaneous fluorescence polarization (FP) measurement of multiple samples was proposed and proven by a proof-of-concept experiment on the viscosity dependence of FP of fluorescein sample in water-ethylene glycol solution and another experiment on the FP immunoassay of prostaglandin E2 sample. The measurement principle of FP is based on the synchronization between the orientation of the liquid crystal molecules and the sampling frequency of a CCD. This report is the first description of the simultaneous FP measurement of multiple samples. This system has a great potential for equipment miniaturization and price reduction as well as providing simultaneous FP measurement of multiple samples.
  • A microfluidic cell culture system for monitoring of sequential changes in endothelial cells after heat stress
    Hidekatsu Tazawa, Kenjiro Sato, Atsuhiro Tsutiya, Manabu Tokeshi, Ritsuko Ohtani-Kaneko
    Thrombosis Research, 136, 2, 328, 334, PERGAMON-ELSEVIER SCIENCE LTD, 2015年08月, [査読有り]
    英語, 研究論文(学術雑誌), Endothelial damage induced by a highly elevated body temperature is crucial in some diseases including viral hemorrhagic fevers. Here, we report the heat-induced sequential changes of endothelial cells under shear stress, which were determined with a microfluidic culture system. Although live cell imaging showed only minor changes in the appearance of heat-treated cells, Hsp70 mRNA expression analysis demonstrated that the endothelial cells in channels of the system responded well to heat treatment. F-actin staining also revealed clear changes in the bundles of actin filaments after heat treatment. Well-organized bundles of actin filaments in control cells disappeared in heat-treated cells cultured in the channel. Furthermore, the system enabled detection of sequential changes in plasminogen activator inhibitor-1 (PAI-1) secretion from endothelial cells. PAI-1 concentration in the effluent solution was significantly elevated for the first 15 min after initiation of heat treatment, and then decreased subsequently. This study provides fundamental information on heat-induced endothelial changes under shear stress and introduces a potent tool for analyzing endothelial secretions. (C) 2015 Elsevier Ltd. All rights reserved.
  • Arrangement of a Nanostructure Array To Control Equilibrium and Nonequilibrium Transports of Macromolecules
    Takao Yasui, Noritada Kaji, Ryo Ogawa, Shingi Hashioka, Manabu Tokeshi, Yasuhiro Horiike, Yoshinobu Baba
    Nano Letters, 15, 5, 3445, 3451, AMER CHEMICAL SOC, 2015年05月, [査読有り]
    英語, 研究論文(学術雑誌), Exploiting the nonequilibrium transport of macromolecules makes it possible to increase the separation speed without any loss of separation resolution. Here we report the arrangement of a nanostructure array in micro-channels to control equilibrium and nonequilibrium transports of macromolecules. The direct observation and separation of macromolecules in the nanopillar array reported here are the first to reveal the nonequilibrium transport, which has a potential to overcome the intrinsic trade-off between the separation Speed and resolution.
  • A Method of Cryoprotection for Protein Crystallography by Using a Microfluidic Chip and Its Application for in Situ X-ray Diffraction Measurements
    Masatoshi Maeki, Ashtamurthy S. Pawate, Kenichi Yamashita, Masahide Kawamoto, Manabu Tokeshi, Paul J. A. Kenis, Masaya Miyazaki
    Analytical Chemistry, 87, 8, 4194, 4200, AMER CHEMICAL SOC, 2015年04月, [査読有り]
    英語, 研究論文(学術雑誌), We demonstrate a seamless and contactless method from protein crystallization to X-ray analysis using a microfluidic chip with the aim of obtaining a complete crystallographic data set of a protein crystal under cryogenic conditions. Our microfluidics-based approach did not require direct manipulation of the protein crystal. Therefore, the microfluidic chip approach is suitable for novices of X-ray analysis of protein crystals. We also investigated the effect of stepwise cryoprotection on the quality of protein crystals. Protein crystals with cryoprotection via on-chip manipulation did not show deterioration of crystallographic quality of the protein crystal. The complete diffraction data set of a protein crystal, which is required for determining the 3D structure of the target protein, is obtainable by a simple manipulation.
  • Carbon nanotubes and modern nanoagriculture
    Maged F. Serag, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Nanotechnology and Plant Sciences: Nanoparticles and Their Impact on Plants, 183, 201, 2015年01月01日, [査読有り]
    論文集(書籍)内論文, © Springer International Publishing Switzerland 2015. Since their discovery, carbon nanotubes have been prominent members of the nanomaterial family. Owing to their extraordinary physical, chemical, and mechanical properties, carbon nanotubes have been proven to be a useful tool in the field of plant science. They were frequently perceived to bring about valuable biotechnological and agricultural applications that still remain beyond experimental realization. An increasing number of studies have demonstrated the ability of carbon nanotubes to traverse different plant cell barriers. These studies, also, assessed the toxicity and environmental impacts of these nanomaterials. The knowledge provided by these studies is of practical and fundamental importance for diverse applications including intracellular labeling and imaging, genetic transformation, and for enhancing our knowledge of plant cell biology. Although different types of nanoparticles have been found to activate physiological processes in plants, carbon nanotubes received particular interest. Following addition to germination medium, carbon nanotubes enhanced root growth and elongation of some plants such as onion, cucumber and rye-grass. They, also, modulated the expression of some genes that are essential for cell division and plant development. In addition, multi-walled carbon nanotubes were evidenced to penetrate thick seed coats, stimulate germination, and to enhance growth of young tomato seedlings. Multi-walled carbon nanotubes can penetrate deeply into the root system and further distribute into the leaves and the fruits. In recent studies, carbon nanotubes were reported to be chemically entrapped into the structure of plant tracheary elements. This should activate studies in the fields of plant defense and wood engineering. Although, all of these effects on plant physiology and plant developmental biology have not been fully understood, the valuable findings promises more research activity in the near future toward complete scientific understanding of the behavior of carbon nanotubes in plants. This chapter focuses on the impact of carbon nanotubes on plants and the potential use of these unique nanomaterials in crop management and plant biotechnology.
  • A portable liquid chromatograph with a battery-operated compact electroosmotic pump and a microfluidic chip device with a reversed phase packed column
    Akihiko Ishida, Mitsutaka Fujii, Takehiro Fujimoto, Shunsuke Sasaki, Ichiro Yanagisawa, Hirofumi Tani, Manabu Tokeshi
    Analytical Sciences, 31, 11, 1163, 1169, Japan Society for Analytical Chemistry, 2015年, [査読有り]
    英語, 研究論文(学術雑誌), A compact and lightweight liquid chromatography system is presented with overall dimensions of 26 cm width × 18 cm length × 21 cm height and weight of 2 kg. This system comprises a battery-operated compact electroosmotic pump, a manual injector, a microfluidic chip device containing a packed column and an electrochemical detector, and a USB buspowered potentiostat. The pumping system was designed for microfluidic-based reversed-phase liquid chromatography in which an electroosmotically generated water stream pushes the mobile phase via a diaphragm for the output. The flow rate ranged from 0 to 10 μL/min and had a high degree of precision. The pumping system operated continuously for over 24 h with dry batteries. The column formed in the microfluidic device was packed with 3-μm ODS particles with a length of 30 mm and a diameter of 0.8 mm. The results presented herein demonstrate the performance of the pumping system and the column using alkylphenols, catecholamine, catechin, and amino acids.
  • An instrument-free, screen-printed paper microfluidic device that enables bio and chemical sensing
    Saeed Mohammadi, Masatoshi Maeki, Reza M. Mohamadi, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Analyst, 140, 19, 6493, 6499, ROYAL SOC CHEMISTRY, 2015年, [査読有り]
    英語, 研究論文(学術雑誌), This paper describes a simple and instrument-free screen-printing method to fabricate hydrophilic channels by patterning polydimethylsiloxane (PDMS) onto chromatography paper. Clearly recognizable border lines were formed between hydrophilic and hydrophobic areas. The minimum width of the printed channel to deliver an aqueous sample was 600 mu m, as obtained by this method. Fabricated microfluidic paper-based analytical devices (mu PADs) were tested for several colorimetric assays of pH, glucose, and protein in both buffer and artificial urine samples and results were obtained in less than 30 min. The limits of detection (LODs) for glucose and bovine serum albumin (BSA) were 5 mM and 8 mu M, respectively. Furthermore, the pH values of different solutions were visually recognised with the naked eye by using a sensitive ink. Ultimately, it is expected that this PDMS-screen-printing (PSP) methodology for mu PADs can be readily translated to other colorimetric detection and hydrophilic channels surrounded by a hydrophobic polymer can be formed to transport fluids toward target zones.
  • Hydrodynamic nonadhesive cell retention in a microfluidic circuit for stressless suspension culture
    Toyohito Naito, Noritada Kaji, Manabu Tokeshi, Takuya Kubo, Yoshinobu Baba, Koji Otsuka
    Analytical Methods, 7, 17, 7264, 7269, ROYAL SOC CHEMISTRY, 2015年, [査読有り]
    英語, 研究論文(学術雑誌), Cell collection based on deterministic lateral displacement (DLD) and cell circulation with a loop channel are two component technologies for stressless cell retention which have been developed with a view to working toward suspension culture in a microfluidic channel. DLD devices with low array angles collect floating S. cerevisiae through an array effectively. The DLD device with an array angle of 2.6 degrees showed an efficiency of 91.7%. Two types of loop channels with a piezoelectrie pump make a stable two-phase laminar flow of a pre-filled fluid and supplied fluid. A loop channel with a connection between an inlet and outlet on the opposite side replaces a filled fluid in the channel with a supplied fluid, which is essential for supplying nutrient rich medium to cells in microfluidic channels as well as retaining cells in a microenvironment without external stresses.
  • Rapid, highly sensitive, and simultaneous detection of staphylococcal enterotoxins in milk by using immuno-pillar devices
    Toshihiro Kasama, Mai Ikami, Wanchun Jin, Keiko Yamada, Noritada Kaji, Yusuke Atsumi, Makoto Mizutani, Atsushi Murai, Akira Okamoto, Takao Namikawa, Michio Ohta, Manabu Tokeshi, Yoshinobu Baba
    Analytical Methods, 7, 12, 5092, 5095, ROYAL SOC CHEMISTRY, 2015年, [査読有り]
    英語, 研究論文(学術雑誌), Staphylococcal enterotoxins (SEs) have repeatedly caused food poisoning incidents worldwide. Some of the challenges associated with food poisoning outbreaks are that traditional detection methods are expensive and require long processing times and trained technicians. Microchannel devices represent a potential detection method by which these difficulties can be overcome. In this paper, we propose that immuno-pillar devices may represent a rapid, highly sensitive, and low-cost analytical system for the simultaneous detection of staphylococcal enterotoxin types A, B, and D (SEA, SEB, and SED) in milk. To prepare milk samples simulating food contaminated with SEs, commercial milk was spiked with equal amounts of SEA, SEB, and SED. A quantitative analysis of the milk samples was performed within 15 min by using the microchannel device. The analysis required only 0.5 mu L of untreated milk sample. The resultant limit of detection was 15.6 pg mL(-1) for each SE, and the total assay time and sensitivity were markedly shorter and higher, respectively, than those for commercially available assay kits. The detection range of each enterotoxin using these devices was estimated as 15.6 pg mL(-1) to 100 ng mL(-1), which completely covers the SE concentrations that can lead to foodborne diseases based on the U.S. Food and Drug Administration's criterion for the infectious SE dose in SE poisoning (1 mu g SE). Using our devices, frequent assessment of food potentially contaminated with SE is possible.
  • A strategy for synthesis of lipid nanoparticles using microfluidic devices with a mixer structure
    Masatoshi Maeki, Tatsuyoshi Saito, Yusuke Sato, Takao Yasui, Noritada Kaji, Akihiko Ishida, Hirofumi Tani, Yoshinobu Baba, Hideyoshi Harashima, Manabu Tokeshi
    RSC Advances, 5, 57, 46181, 46185, ROYAL SOC CHEMISTRY, 2015年, [査読有り]
    英語, 研究論文(学術雑誌), Formation behavior of lipid nanoparticles (LNPs) in microfluidic devices with a staggered herringbone micromixer (SHM) structure was investigated. The fundamental role for SHMs in LNP formation was demonstrated by determining such factors as the limiting SHM cycle numbers and the effect of flow rate. The SHM cycle numbers and the position of the first SHM were as significant as factors as the flow rate condition for producing the small-size LNPs.
  • イムノピラーデバイスの高性能化:抗体固定化担体の改良
    西脇 奈菜子, 笠間 敏博, 石田 晃彦, 谷 博文, 馬場 嘉信, 渡慶次 学
    分析化学, 64, 5, 329, 335, 日本分析化学会, 2015年, [査読有り]
    日本語, 研究論文(学術雑誌), 著者らはこれまでに,光硬化性樹脂と抗体を固定化したビーズを組み合わせた,イムノアッセイによる疾病マーカー検出のためのイムノピラーデバイスと呼ばれるマイクロデバイスの開発を行ってきた.しかし,臨床診断に応用するためには,さらなる性能の向上が求められていた.そこで,イムノピラーデバイスの高性能化を目指し,抗体固定化担体の改良に取り組んだ.従来のイムノピラーデバイスはポリスチレンビーズに抗体を物理吸着により固定化してきた.本研究では,化学結合によりビーズ表面に抗体を固定化することのできるアフィニティビーズを用いたイムノピラーデバイスを作製し,C反応性タンパク質(CRP)の検出を試みた.インキュベーション時間とピラーの直径の検討を行った結果,全測定時間23分で,検出限界0.1 ng mL-1のCRPを測定することが可能となり,従来のデバイスよりも感度が100倍高いことが明らかとなった.本イムノピラーデバイスの長期保存安定性の評価を行ったところ,9か月以上保存可能であることが分かった.以上により,従来よりも優れた感度を有する,高性能なイムノアッセイ用マイクロデバイスを開発することができた.
  • マイクロ抽出場によるヒト腫瘍細胞由来のマイクロRNA抽出法
    岡本 行広, 日比野 理人, 加地 範匡, 渡慶次 学, 馬場 嘉信
    分析化学, 64, 1, 9, 13, 日本分析化学会, 2015年, [査読有り]
    日本語, 研究論文(学術雑誌), The importance of micro RNA analysis has been significantly increasing because the role of micro RNA in the human body has been gradually revealed. Despite its importance, the analysis has suffered from several troublesome pretreatments, which hamper any easy analysis. Therefore, an easy and high-throughput pretreatment method has been demanded. In this paper, we focused on the great advantages of microchip pretreatments over conventional manual pretreatments and developed a microchip for micro RNA extraction. To simplify microchip fabrication, we adopted poly(dimethyl siloxane) (PDMS) microchip and a silica membrane, which has rolls in RNA extraction fields. With silica membranes and the adhesion nature of PDMS, we could easily fabricate RNA extraction fields in the microchip. With this microchip, we successfully extracted micro RNA from cancer tumor cells. Though this is a preliminary experiment, and still has many improvement points, our device is expected to be applied for easy and fast micro RNA extraction from biological samples.
  • Synthesis and Reactions of Ynolates via a Stop-Flow Method with a Flow Microreactor
    Toshiya Yoshiiwa, Satoshi Umezu, Manabu Tokeshi, Yoshinobu Baba, Mitsuru Shindo
    Journal of Flow Chemistry, 4, 4, 180, 184, AKADEMIAI KIADO RT, 2014年12月, [査読有り]
    英語, 研究論文(学術雑誌), We report a method for the generation and subsequent reaction of ynolates in a flow microreactor via a stop-flow process. This procedure allowed for the synthesis of ynolates at ambient temperature within 11 min via a Li-Br exchange reaction with sec-butyllithium, whereas the corresponding batch process generally requires low temperature control and extended reaction times of up to 1 h. The stop-flow method is especially useful for optimizing the reaction time without having to use various microtube lengths. The resulting ynolates were applied to the olefination of carbonyl compounds and to pyrrole synthesis. These results indicate the practical utility of the ynolate reaction and should contribute to progress in flash chemistry.
  • Bioluminescence immunoassay using luciferase-encapsulated liposome as a label
    Yusuke Nakatani, Chiaki Shido, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Luminescence, 29, 83, 84, WILEY-BLACKWELL, 2014年08月, [査読有り]
    英語
  • Bioluminescence Assay Based on Controlled Inhibitory Effect on Firefly Luciferase
    Ryoko Kurishiba, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi
    Luminescence, 29, 78, 78, WILEY-BLACKWELL, 2014年08月, [査読有り]
    英語
  • Effect of reductants on oscillatory chemiluminescence of fluorescein catalyzed by horseradish peroxidase
    Hirofumi Tani, Ai Masuyama, Akihiko Ishida, Manabu Tokeshi
    Luminescence, 29, 99, 100, WILEY-BLACKWELL, 2014年08月, [査読有り]
    英語
  • Generation of ynolates via reductive lithiation using flow microreactors
    Satoshi Umezu, Toshiya Yoshiiwa, Manabu Tokeshi, Mitsuru Shindo
    Tetrahedron Letters, 55, 10, 1822, 1825, PERGAMON-ELSEVIER SCIENCE LTD, 2014年03月, [査読有り]
    英語, 研究論文(学術雑誌), A new method has been developed for the generation and subsequent reaction of ynolates in a micro flow reactor system. This new procedure allowed for ynolates to be prepared at 0 degrees C or ambient temperature within 1 min via a reductive lithiation reaction, whereas the corresponding batch processes generally require low temperature control and extended reaction times of up to 1 h. The resulting ynolates were applied to the olefination of carbonyl compounds, with the reactions reaching completion in a much shorter reaction time in the continuous flow reactor than the batch reactor. These results highlight the practical utility of the ynolate reaction, and represent the first reported example of the use of lithium naphthalenide in a flow microreactor, which would contribute to progress of the flash chemistry. (C) 2014 Elsevier Ltd. All rights reserved.
  • Microfluidic biosensor for the detection of DNA by fluorescence enhancement and the following streptavidin detection by fluorescence quenching
    Jun Wang, Michihiko Aki, Daisuke Onoshima, Kenji Arinaga, Noritada Kaji, Manabu Tokeshi, Shozo Fujita, Naoki Yokoyama, Yoshinobu Baba
    Biosensors and Bioelectronics, 51, 280, 285, ELSEVIER ADVANCED TECHNOLOGY, 2014年01月, [査読有り]
    英語, 研究論文(学術雑誌), We reported an optical DNA/protein microfluidic sensor which consists of single stranded (ss) DNA-Cy3 probes on gold surface and simple line-shape microfluidic channel. These ssDNA-Cy3 probes with random sequence in bulk solution or on gold surface exhibits fluorescence enhancement after binding with complementary ssDNA (cssDNA) targets. Particularly it did not require complicated design or hairpin-like stem-loop conformation, which made it easier to be made and applied in analytes detection by fluorescence switching techniques. Using ssDNA-cy3 probes attached on gold surface in a microfluidic channel, strong fluorescence enhancement was measured by ssDNA with cssDNA binding or ssDNA with cssDNA-biotin binding. The following introduction of streptavidin resulted in fluorescence quenching (fluorescence decrease) because of the binding of hybridized DNA-biotin with streptavidin. This sensor showed strong affinity and high sensitivity toward the streptavidin, the minimum detectable concentration for streptavidin was 1 pM, equating to an absolute detection limit of 60 amol in this microfluidic channel. Microfluidic channel height and flow rate is optimized to increase surface reaction efficiency and fluorescence switching efficiency. In contrast to previously reported optical molecular beacon approach, this sensor can be used not only for the detection of cssDNA target, but also for the detection of streptavidin. This microfluidic sensor offers the promise of analyzing kinds of molecular targets or immunoreactions. (C) 2013 Elsevier B.V. All rights reserved.
  • Nanopillar array chip integrated with on-line stacking for fast DNA separation with high sensitivity and high resolution
    Takao Yasui, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yasuhiro Horiike, Yoshinobu Baba
    Microfluidics and Nanofluidics, 14, 6, 961, 967, SPRINGER HEIDELBERG, 2013年06月, [査読有り]
    英語, 研究論文(学術雑誌), Recent developments of nanofabrication techniques have created a trend switching from randomly ordered polymeric matrices, such as gel, to highly ordered sieving nanostructures in the separation of biomolecules. These nanostructures have enormous potential for fast separation of biomolecules, while nanostructure-based separation techniques suffer from critical scaling problems; they are efficient in handling less than nanoliter amounts of sample fluids, but most biomolecule samples are available in a liquid volume that is over several microliter, leading to a reduction in sensitivity and resolution. In this study, we developed a nanopillar array chip integrated with an easy and rapid on-line stacking method and achieved fast DNA separation with high sensitivity and high resolution. The developed on-line stacking method is based on the balance of two forces driven by electric fields: electroosmotic flow (EOF) and electrophoresis. The EOF mobility from the microchannel to the nanopillar-channel is drastically decreased, while, on the other hand, electrophoresis has constant mobilities in the whole length of the channels. The on-line stacking was realized at the well-balanced position of the two forces, and the on-line stacking using the nanopillar array chip can also be achieved within 10 s by just applying electric voltages without any other special reagents and materials. After applying on-line stacking using the nanopillar array chip, the relative fluorescence intensity increased 1,000-fold, and the resolution was twice as good as that without on-line stacking.
  • Highly efficient electrochemical valence control of uranium using microfluidic chip equipped with microelectrodes
    Takehiko Tsukahara, Hiroyasu Hotokezaka, Masayuki Harada, Yoshikuni Kikutani, Manabu Tokeshi, Yasuhisa Ikeda
    Microfluidics and Nanofluidics, 14, 6, 989, 994, SPRINGER HEIDELBERG, 2013年06月, [査読有り]
    英語, 研究論文(学術雑誌), We have developed a novel microchip equipped with a microchannel and Pt microelectrode array for electrochemically controlling valences of actinide (An) species. The square wave voltammograms of the redox reaction of potassium hexacyanoferrate(II) in the microchannel were measured. We found that the fabricated Pt microelectrode array has superior performances for the detection of the electrochemically active species in the microchannel. Therefore, the potentiostatic electrolysis experiments of uranium ions were carried out in the microchannel, and the concentration changes of uranium ions accompanied by the potentiostatic electrolysis were examined using thermal lens microscope. The results showed that the redox reactions between U(VI) and U(IV) can be performed completely in a microchannel in a few minutes, that is, the microscale reaction is accelerated by a factor of more than 10 compared with the bulk solution reactions taking hours mostly. The developed microchip was found to have enough performances for realizing rapid and highly efficient redox reactions for An species, which are impossible in the bulk reactions.
  • DNA manipulation and separation in sublithographic-scale nanowire array
    Takao Yasui, Sakon Rahong, Koki Motoyama, Takeshi Yanagida, Qiong Wu, Noritada Kaji, Masaki Kanai, Kentaro Doi, Kazuki Nagashima, Manabu Tokeshi, Masateru Taniguchi, Satoyuki Kawano, Tomoji Kawai, Yoshinobu Baba
    ACS Nano, 7, 4, 3029, 3035, 2013年04月, [査読有り]
    英語, 研究論文(学術雑誌), Electrokinetic manipulations of biomolecules using artificial nanostructures within microchannels have proven capability for controlling the dynamics of biomolecules. Because there is an inherent spatial size limitation to lithographic technology, especially for nanostructures with a small diameter and high aspect ratio, manipulating a single small biomolecule such as in DNA elongation before nanopore sequencing is still troublesome. Here we show the feasibility for self-assembly of a nanowire array embedded in a microchannel on a fused silica substrate as a means to manipulate the dynamics of a single long T4-DNA molecule and also separate DNA molecules. High-resolution optical microscopy measurements are used to clarify the presence of fully elongated T4-DNA molecules in the nanowire array. The spatial controllability of sublithographic-scale nanowires within microchannels offers a flexible platform not only for manipulating and separating long DNA molecules but also for integrating with other nanostructures to detect biomolecules in methods such as nanopore sequencing. © 2013 American Chemical Society.
  • Parallel Real-Time PCR on a Chip for Genetic Tug-of-War (gTOW) Method
    Toyohiro Naito, Ai Yatsuhashi, Noritada Kaji, Taeko Ando, Kazuo Sato, Hisao Moriya, Hiroaki Kitano, Takao Yasui, Manabu Tokeshi, Yoshinobu Baba
    Analytical Sciences, 29, 3, 367, 371, JAPAN SOC ANALYTICAL CHEMISTRY, 2013年03月, [査読有り]
    英語, 研究論文(学術雑誌), A microchip-based real-time polymerase chain reaction (PCR) device has been developed for the genetic tug-of-war (gTOW) method that provides quantitative data for research on biorobustness and systems biology. The device was constructed of a silicon glass chip, a temperature controlling Peltier element, and a microscope. A parallel real-time amplification process of target genes on the plasmids and the housekeeping genes in a model eukaryote Saccharomyces cerevisiae were detected simultaneously, and the copy number of the target genes were estimated. The device provides unique quantitative data that can be used to augment understanding of the system-level properties of living cells.
  • Application of IgY to sandwich enzyme-linked immunosorbent assays, lateral flow devices, and immunopillar chips for detecting staphylococcal enterotoxins in milk and dairy products.
    Wanchun Jin, Keiko Yamada, Mai Ikami, Noritada Kaji, Manabu Tokeshi, Yusuke Atsumi, Makoto Mizutani, Atsushi Murai, Akira Okamoto, Takao Namikawa, Yoshinobu Baba, Michio Ohta
    Journal of Microbiological Methods, 92, 3, 323, 31, 2013年03月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Staphylococcal enterotoxins (SEs), produced by Staphylococcus aureus, are a major cause of staphylococcal food poisoning. Traditionally, sandwich enzyme-linked immunosorbent assay (ELISA) and reverse passive latex agglutination with rabbit antibody IgG have been used to detect SEs. However, most of these kits require a long processing time and there is a risk of false-positive results since IgG reacts nonspecifically with protein A produced by S. aureus. In this study, we prepared antienterotoxin chicken IgY antibodies specific for each SE (SEA to SEE) without reaction to protein A, which enabled a drastic reduction in nonspecific reactions. ELISAs, lateral flow device (LFDs), and IgY-based immunopillar chips were developed for SE detection. All the ELISAs developed were as sensitive as commercially available kits. The SEs in milk were successfully detected by the ELISAs, LFDs, and immunopillar chips without any sample pretreatment. The LFD could detect SEA even at the low concentration of 0.2 ng/ml within 15 min in milk. The detection limit of the immunopillar chips for the SEs ranged from 0.01 to 0.1 ng/ml in milk; the SEs were detected within 12 min and specialized skills were not required. The ELISA and LFD detected SEA in dairy products artificially contaminated with S. aureus, including ice cream, yogurt, and café au lait, in a dose-dependent manner. In conclusion, IgY allows highly specific detection of SEs, and ELISAs, LFDs, and immunopillar chips should be useful tools for screening SEs in milk and dairy products.
  • Quantum Dots Conjugated with Transferrin for Brain Tumor Cell Imaging               
    Hiroshi Yukawa, Ryoko Tsukamoto, Ayano Kano, Yukihiro Okamoto, Manabu Tokeshi, Tetsuya Ishikawa, Masaaki Mizuno, Yoshinobu Baba
    Journal of Cell Science and Therapy, 4, 150-1, 150-7, 2013年, [査読有り]
    英語, 研究論文(学術雑誌)
  • Enzyme-catalysed reaction for long-term fluorescent observation of single DNA molecules
    Takao Yasui, Koki Motoyama, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    RSC Advances, 3, 10, 3237, 3240, ROYAL SOC CHEMISTRY, 2013年, [査読有り]
    英語, 研究論文(学術雑誌), The technical development of long-term fluorescent observation of single DNA molecules is central to fields ranging from molecular biological detection to understanding the physical properties of them under a microscope. Here, we address this challenge using protocatechuic acid and protocatechuate-3,4-dioxygenase (PADase) and demonstrate fluorescent lifetimes of dyed single DNA molecules of 150-180 s, three times longer than those without any treatments.
  • Temperature-driven self-actuated microchamber sealing system for highly integrated microfluidic devices
    Toyohiro Naito, Rerngchai Arayanarakool, Severine Le Gac, Takao Yasui, Noritada Kaji, Manabu Tokeshi, Albert van den Berg, Yoshinobu Baba
    Lab on a Chip, 13, 3, 452, 458, ROYAL SOC CHEMISTRY, 2013年, [査読有り]
    英語, 研究論文(学術雑誌), We present here a novel microchamber sealing valve that is self-actuated by a pressure change during the temperature change in the thermal activation of reactions. Actuation of our valve requires only the use of the same heating device as employed for the reactions. A thermoplastic UV-curable polymer is used as a device material; the polymer allows realization of the temperature-driven valve actuation as well as the fabrication of multi-layered devices. The self-actuated valve achieves effective sealing of the microchamber for the polymerase chain reaction (PCR) even at 90 degrees C, which is essential for developing highly parallel PCR array devices without the need for complicated peripherals to control the valve operation.
  • Establishment of portable immunoassay system for early diagnosis.
    Toshihiro Kasama, Yutaka Hasegawa, Hiroyuki Matsumoto, Haruyasu Kondo, Tsutomu Ozawa, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    2013 International Symposium on Micro-NanoMechatronics and Human Science, MHS 2013, 1, 3, IEEE, 2013年, [査読有り]
    研究論文(国際会議プロシーディングス), We have developed immunopillar devices for rapid and easy-to-use immunoassay with pM-fM detection sensitivity, but long total assay time (sample-in-answer-out) and the compatibility with a portable detection system have still remained as major problems toward the point-of-care testing (POCT). We report here next generation immunopillar devices and portable detection system suitable for them. Thin structure of those devices allowed us to wash nonspecifically bound antigens and fluorescent-labeled secondary antibodies in a minute, resulting in the dramatic reduction in the total assay time. In addition, by using the portable detection system, we gained the concentrations of C-reactive protein in human sera while preserving pM detection sensitivity. The total assay time was 20 minutes per sample. Our immunoassay system possesses the potential for use in POCT. © 2013 IEEE.
  • 超解像顕微鏡の世界 : 波長の壁を超えて見る(新連載・第1回)超解像顕微鏡とは : Abbeの法則への挑戦
    加地 範匡, 渡慶次 学, 馬場 嘉信
    現代化学, 1, 502, 50, 54, 東京化学同人, 2013年01月
    日本語
  • Inkjet Injection of DNA Droplets for Microchannel Array Electrophoresis
    Takao Yasui, Yosuke Inoue, Toyohiro Naito, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Analytical Chemistry, 84, 21, 9282, 9286, AMER CHEMICAL SOC, 2012年11月, [査読有り]
    英語, 研究論文(学術雑誌), We demonstrated DNA droplets could be injected with an inkjet injector for microchannel array electrophoresis and attained high throughput analysis of biomolecules. This injection method greatly reduced both analysis time and sample amount, compared with a conventional microchip electrophoresis method, and allowed high parallelization of a microchannel array on a small substrate. Since we do not need to use complicated electric programs or microchannel design, our injection method should facilitate omics analyses and contribute to high performance clinical assays.
  • Fabrication of Functionalized Double-Lamellar Multifunctional Envelope-Type Nanodevices Using a Microfluidic Chip with a Chaotic Mixer Array
    Katsuma Kitazoe, Yeon-Su Park, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Kentaro Kogure, Hideyoshi Harashima, Yoshinobu Baba
    PLOS ONE, 7, 6, e39057-1, 8, PUBLIC LIBRARY SCIENCE, 2012年06月, [査読有り]
    英語, 研究論文(学術雑誌), Multifunctional envelope-type nanodevices (MENDs) are very promising non-viral gene delivery vectors because they are biocompatible and enable programmed packaging of various functional elements into an individual nanostructured liposome. Conventionally MENDs have been fabricated by complicated, labor-intensive, time-consuming bulk batch methods. To avoid these problems in MEND fabrication, we adopted a microfluidic chip with a chaotic mixer array on the floor of its reaction channel. The array was composed of 69 cycles of the staggered chaotic mixer with bas-relief structures. Although the reaction channel had very large Peclet numbers (>10(5)) favorable for laminar flows, its chaotic mixer array led to very small mixing lengths (<1.5 cm) and that allowed homogeneous mixing of MEND precursors in a short time. Using the microfluidic chip, we fabricated a double-lamellar MEND (D-MEND) composed of a condensed plasmid DNA core and a lipid bilayer membrane envelope as well as the D-MEND modified with trans-membrane peptide octaarginine. Our lab-on-a-chip approach was much simpler, faster, and more convenient for fabricating the MENDs, as compared with the conventional bulk batch approaches. Further, the physical properties of the on-chip-fabricated MENDs were comparable to or better than those of the bulk batch-fabricated MENDs. Our fabrication strategy using microfluidic chips with short mixing length reaction channels may provide practical ways for constructing more elegant liposome-based non-viral vectors that can effectively penetrate all membranes in cells and lead to high gene transfection efficiency.
  • Monitoring transplanted adipose tissue-derived stem cells combined with heparin in the liver by fluorescence imaging using quantum dots
    Hiroshi Yukawa, Masaki Watanabe, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yoshitaka Miyamoto, Hirofumi Noguchi, Yoshinobu Baba, Shuji Hayashi
    Biomaterials, 33, 7, 2177, 2186, ELSEVIER SCI LTD, 2012年03月, [査読有り]
    英語, 研究論文(学術雑誌), Adipose tissue-derived stem cell (ASC) transplantation, when used in combination with heparin, has proven to be an effective treatment for acute liver failure in mice. However, the behavior and organ-specific accumulation of transplanted ASCs alone or in combination with heparin is poorly understood. In this paper, we investigated whether quantum dots (QDs) labeling using octa-arginine peptide (R8) for ASCs could be applied for in vivo fluorescence imaging in mice with acute liver failure, and analyzed the behavior and organ-specific accumulation of ASCs that were transplanted alone or in combination with heparin using an IVIS (R) Spectrum analysis. Almost all of the transplanted ASCs were observed to accumulate in the lungs within 10 min without heparin. However, when heparin was used in combination with the ASCs, the accumulation of the transplanted ASCs was found not only in the lungs but also in the liver. The region of interest (ROI) analysis of ex vivo fluorescence imaging showed that the accumulation rate of transplanted ASCs in the liver increased to about 30%. In the time course analysis, the accumulation rate of ASCs in the liver was about 10% in 1 day and was maintained at that level for at least 2 day. We observed that heparin was effective for increasing the accumulation of transplanted ASCs in the liver using fluorescence imaging technology. We suggest that fluorescence imaging by means of QDs labeling using R8 can be useful for tracing the transplanted cells. (C) 2011 Elsevier Ltd. All rights reserved.
  • Introducing carbon nanotubes into living walled plant cells through cellulase-induced nanoholes
    Maged F. Serag, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    RSC Advances, 2, 2, 398, 400, ROYAL SOC CHEMISTRY, 2012年, [査読有り]
    英語, 研究論文(学術雑誌), Carbon nanotubes can intracellularly transport through different cellular barriers. However, their use in plant cells is limited by the cellulosic cell wall surrounding these cells. Here we show that cup-stacked carbon nanotubes with cellulase immobilized on their sidewalls and tips penetrate the cell wall and transport intracellularly through cellulase-induce nanoholes.
  • Confocal Microscopic Evaluation of Mixing Performance for Three-Dimensional Microfluidic Mixer
    Takao Yasui, Yusuke Omoto, Keiko Osato, Noritada Kaji, Norikazu Suzuki, Toyohiro Naito, Yukihiro Okamoto, Manabu Tokeshi, Eiji Shamoto, Yoshinobu Baba
    Analytical Sciences, 28, 1, 57, 59, JAPAN SOC ANALYTICAL CHEMISTRY, 2012年01月, [査読有り]
    英語, 研究論文(学術雑誌), We developed a confocal microscopic method for a quantitative evaluation of the mixing performance of a three-dimensional microfluidic mixer. We fabricated a microfluidic baker's transformation (MBT) mixer as a three-dimensional passive-type mixer for the efficient mixing of solutions. Although the MBT mixer is one type of ideal mixers, it is hard to evaluate its mixing performance, since the MBT mixer is based on several cycles of complicated three-dimensional microchannel structures. We applied the method developed here to evaluate the mixing of water and a fluorescein isothiocyanate (FITC; diffusion coefficient, 4.9 x 10(-10) m(2) s(-1)) solution by the MBT mixer. This method enables us to capture vertical section images for the fluid distributions of FITC and water at different three-dimensional microchannel structures of the MBT device. These images are in good agreement with those of mixing images based on numerical simulations. The mixing ratio could be calculated by the fluorescence intensity at each pixel of the vertical section image; complete mixing is recognized by a mixing ratio of more than 90%. The mixing ratios are measured at different cycles of the MBT mixer by changing the flow rate; the mixing performance is evaluated by comparisons with the mixing ratio of the straight microchannel without the MBT mixer.
  • The plant cell uses carbon nanotubes to build tracheary elements
    Maged F. Serag, Noritada Kaji, Manabu Tokeshi, Alberto Bianco, Yoshinobu Baba
    Integrative Biology, 4, 2, 127, 131, ROYAL SOC CHEMISTRY, 2012年, [査読有り]
    英語, 研究論文(学術雑誌), Since their discovery, carbon nanotubes (CNTs) have been eminent members of the nanomaterial family. Because of their unique physical, chemical and mechanical properties, they are regarded as new potential materials to bring enormous benefits in cell biology studies. Undoubtedly, the first step to prove the advantages of CNTs is to understand the basic behavior of CNTs inside the cells. In a number of studies, CNTs have been demonstrated as new carrier systems for the delivery of DNA, proteins and therapeutic molecules into living cells. However, post-uptake behavior of CNTs inside the cells has not received much consideration. Utilizing the plant cell model, we have shown in this study that the plant cells, differentiating into tracheary elements, incorporate cup-stacked carbon nanotubes (CSCNTs) into cell structure via oxidative cross-linking of monolignols to the nanotubes surface during lignin biosynthesis. This finding highlights the fate of CNTs inside plant cells and provides an example on how the plant cell can handle internalized carbon nanomaterials.
  • Aqueous Phase Synthesized CdSe Magic-Sized Clusters: Solution Composition Dependence of Adsorption Layer Structure
    Yeon-Su Park, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Journal of Nanoscience and Nanotechnology, 12, 1, 539, 546, AMER SCIENTIFIC PUBLISHERS, 2012年01月, [査読有り]
    英語, 研究論文(学術雑誌), We report dispersion solution composition dependence of the adsorption layer structure and the physical and optical properties of aqueous phase-synthesized semiconductor nanoparticles (NPs). We synthesized cysteine (Cys)-capped CdSe NPs with well-defined core structures, dispersed them in a series of aqueous solutions with different compositions, and then investigated their adsorption layer structure and physical and optical properties. Each CdSe NP consisted of a (CdSe)(33) or (CdSe)(34) magic-sized cluster (d similar to 1.45 nm) core, a ligand-Cys shell, and an adsorption layer. The dispersion solution composition strongly affected the adsorption layer structure of the CdSe NPs. The solution with a composition close to that of the as-prepared solution stabilized the physical and optical properties of the NPs. The solution with a composition different from that of the as-prepared solution, however, resulted in large changes in their adsorption layer structure and thus their physical and optical properties. The solution composed of neutral or weakly charged Cys and Cd-Cys complexes led to the adsorption layer with low charge density and that destabilized the NPs. The solution containing only neutral or weakly charged forms of Cys, without Cd-Cys complexes, was favorable to the formation of a thick adsorption layer with low charge density and that destabilized the NPs. The amount of adsorbed Cys in the adsorption layer depended on the dispersion solution composition. However, the amount of adsorbed Cd-Cys complexes in the adsorption layer was almost constant regardless of the dispersion solution composition.
  • パイこね変換に基づく量産対応・高速ミキサの開発
    尾本 悠輔, 加藤 大香士, 鈴木 教和, 安井 隆雄, 大里 恵子, 加地 範匡, 渡慶次 学, 馬場 嘉信, 酒井 康彦, 社本 英二
    日本機械学会論文集 B編, 78, 788, 762, 768, 一般社団法人 日本機械学会, 2012年, [査読有り]
    日本語, 研究論文(学術雑誌), We developed a new passive-type lamination mixer for high viscosity fluid with a low Reynolds number, based on the baker's transformation (BT). BT is the best transformation for mixing fluids of laminar flow. However, there was difficulty in mass-producing the BT structure especially for micro devices like MicroTAS, Lab-on-a-Chip and Micro-Reactors, because conventional BT mixers require three-dimensional (3D) piping structures. We have successfully developed the easy-to-massproduce BT mixer by changing that concept of 3D piping structures to 3D channel structures. The 3D channel structures are not easy to produce by photolithography unlike the conventional mixers, while they can be easily mass-produced by molding once their 3D molds are produced. In this report, we newly developed a miniature scale BT mixer to meet the needs for mixing high viscosity fluids in food processing, resin blending, etc. An experiment for mixing different colored hardening silicone elastomers was performed by using the prototype mixer made of aluminum alloy, and the good BT mixing result was obtained, with observing several cross sectional patterns. The numerical fluid analysis also gave similar results of the patterns to those observed in the experiment.
  • A deep microfluidic absorbance detection cell replicated from a thickly stacked SU-8 dry film resist mold
    Daisuke Onoshima, Jun Wang, Michihiko Aki, Kenji Arinaga, Noritada Kaji, Manabu Tokeshi, Shozo Fujita, Naoki Yokoyama, Yoshinobu Baba
    Analytical Methods, 4, 12, 4368, 4372, ROYAL SOC CHEMISTRY, 2012年, [査読有り]
    英語, 研究論文(学術雑誌), Dry film resist SU-8 was used to make a thick mold for soft lithography of a poly(dimethylsiloxane) (PDMS) microfluidic chip with deep channels. The stacking of the SU-8 film enabled an ultra-thick (up to 500 mu m) resist process on Si wafer. This process was fast and highly reproducible compared with the conventional liquid SU-8 process. The deep channel in the PDMS chip was utilized as a micro-flow cell for sensitive absorbance measurement. Sunset Yellow FCF dye was used to demonstrate absorption spectroscopy in the deep channel. Since the channel depth was proportional to the optical path length, which was proportional to the absorbance value, the PDMS chip achieved a detection limit (15.9 mu M) comparable to U- or Z-shaped microfabricated absorbance detection cells in glass. Calibration curves for different solution concentrations were obtained with good R-2 values (similar to 1).
  • Size-selective synthesis of ultrasmall hydrophilic CdSe nanoparticles in aqueous solution at room temperature.
    Yeon-Su Park, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Methods in molecular biology (Clifton, N.J.), 906, 125, 41, 2012年, [査読有り], [国際誌]
    英語, Hydrophilic semiconductor nanoparticles are very attractive for various biological applications, such as in optical sensing, tracing, and imaging of biological molecules-of-interest, because of their broad excitation wavelength, tunable emission wavelength, strong photoluminescence, and relatively high stability against photobleaching and chemicals. Compared to organic phase synthesis and subsequent surface modification, aqueous phase synthesis approaches provide multiple advantages for obtaining hydrophilic semiconductor nanoparticles. Here, we describe methods for the size-selective growth and stabilization of ultrasmall hydrophilic CdSe nanoparticles in aqueous solution at room temperature by using amino acid cysteine or one of its derivatives as a surface capping agent.
  • Characterization of low viscosity polymer solutions for microchip electrophoresis of non-denatured proteins on plastic chips
    Takao Yasui, Mohamad Reza Mohamadi, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yoshinobu Baba
    Biomicrofluidics, 5, 4, 044114-1, 9, AMER INST PHYSICS, 2011年12月, [査読有り]
    英語, 研究論文(学術雑誌), In this paper, we study characteristics of polymers (methylcellulose, hypromellose ((hydroxypropyl)methyl cellulose), poly(vinylpyrrolidone), and poly(vinyl alcohol)) with different chemical structures for microchip electrophoresis of non-denatured protein samples in a plastic microchip made of poly(methyl methacrylate) (PMMA). Coating efficiency of these polymers for controlling protein adsorption onto the channel surface of the plastic microchip, wettability of the PMMA surface, and electroosmotic flow in the PMMA microchannels in the presence of these polymers were compared. Also relative electrophoretic mobility of protein samples in solutions of these polymers was studied. We showed that when using low polymer concentrations (lower than the polymer entanglement point) where the sieving effect is substantially negligible, the interaction of the samples with the polymer affected the electrophoretic mobility of the samples. This effect can be used for achieving better resolution in microchip electrophoresis of protein samples. (C) 2011 American Institute of Physics. [doi:10.1063/1.3668233]
  • Estimation of the Distribution of Intravenously Injected Adipose Tissue-Derived Stem Cells Labeled with Quantum Dots in Mice Organs through the Determination of their Metallic Components by ICPMS
    Yuka Takasaki, Masaki Watanabe, Hiroshi Yukawa, Akhmad Sabarudin, Kazumi Inagaki, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yoshitaka Miyamoto, Hirofumi Noguchi, Tomonari Umemura, Shuji Hayashi, Yoshinobu Baba, Hiroki Haraguchi
    Analytical Chemistry, 83, 21, 8252, 8258, AMER CHEMICAL SOC, 2011年11月, [査読有り]
    英語, 研究論文(学術雑誌), Adipose tissue-derived stein cells (ASCs) have shown promise in cell therapy because of their ability to self-renew damaged or diseased organs and easy harvest. To ensure the distribution and quantification of the ASCs injected from tail vein, several whole-body imaging techniques including fluorescence optical imaging with quantum dots (QDs) have been employed, but they may suffer from insufficient sensitivity and accuracy. Here, we report quantitative distribution of ASCs in various organs (heart, lung, liver, spleen, and kidney) of mice, which were intravenously injected with QDs-labeled ASCs (Qps-ASCs), through the detection of QDs-derived metallic components by inductively coupled plasma mass spectrometry (ICPMS). For accurate and precise determination, each organ was harvested and completely digested with a mixture of HNO3 and H2O2 in a microwave oven prior to ICPMS measurement, which was equipped with a microflow injection system and a laboratory-made capillary-attached micronebulizer. After optimization, 16 elements including major components (Cd, Se, and Te) of QDs and essential elements (Na, K, Mg, Ca, P, S, Mn, Fe, Co, Cu, Zn, Se, Sr, and Mo) were successfully determined in the organs. As compared to untreated mice, QDs-ASCs-treated mice showed significantly higher levels of Cd and Te in all organs, and as expected, the molar ratio of Cd to Te in each organ was in good agreement with the molar composition ratio in the QDs. This result indicates that the increment of Cd (or Te) can be used as a tracer for calculating the distribution of ASCs in mice organs. As a result of the calculation, 36.8%, 19.1%, 0.59%, 0.49%, and 0.25% of the total ASCs injected were estimated to be distributed in the liver, lung, heart, spleen, and kidney, respectively.
  • Rapid Qualitative Evaluation of DNA Transcription factor NF-κB by Microchip Electrophoretic Mobility Shift Assay in Mammalian Cells
    Sonoko Inoue, Noritada Kaji, Masatoshi Kataoka, Yasuo Shinohara, Yukihiro Okamoto, Manabu Tokeshi, Yoshinobu Baba
    Electrophoresis, 32, 22, 3241, 3247, WILEY-BLACKWELL, 2011年11月, [査読有り]
    英語, 研究論文(学術雑誌), We have developed a separation technique for DNAprotein complex based on electrophoretic mobility shift assay (EMSA) by microchip electrophoresis, which we call microchip electrophoretic mobility shift assay (mu EMSA). To evaluate the mu EMSA, we employed recombinant human nuclear factor-?B (rhNF-B) and its consensus double-stranded oligonucleotide (dsOligo) fluorescently labeled with Cy5. We carried out the electrophoretic separation of the consensus dsOligo-rhNF-B complex and the unbound dsOligo in methylcellulose solution and confirmed rapid (similar to 200s) and reliable identification and semi-quantitation of the specific interaction between dsOligo and rhNF-B. The binding specificity of rhNF-?B was confirmed by introducing non-fluorescently labeled consensus oligonucleotide as a competitor. The progression of the binding reaction under various incubation times was monitored, and it was found that the dsOligo and rhNF-B complex formation reached equilibrium (ca. 90% of the dsOligo was bound to rhNF-B) after 5min. Furthermore, without any purification process, even crude NF-?B in nuclear extracts from HeLa cells was specifically detected within 120s by the mu EMSA.
  • Functional Platform for Controlled Subcellular Distribution of Carbon Nanotubes
    Maged F. Serag, Noritada Kaji, Enrica Venturelli, Yukihiro Okamoto, Kazuyoshi Terasaka, Manabu Tokeshi, Hajime Mizukami, Kevin Braeckmans, Alberto Bianco, Yoshinobu Baba
    ACS Nano, 5, 11, 9264, 9270, AMER CHEMICAL SOC, 2011年11月, [査読有り]
    英語, 研究論文(学術雑誌), As nanoparticles can cross different cellular barriers and access different tissues, control of their uptake and cellular fate presents a functional approach that will be broadly applicable to nanoscale technologies in cell biology. Here we show that the trafficking of single-walled carbon nanotubes (SWCNTs) through various subcellular membranes of the plant cell is facilitated or inhibited by attaching a suitable functional tag and controlling medium components. This enables a unique control over the uptake and the subcellular distribution of SWCNTs and provides a key strategy to promote their cellular elimination to minimize toxicity. Our results also demonstrate that SWCNTs are involved in a carrier-mediated transport (CMT) inside cells; this is a phenomenon that scientists could use to obtain novel molecular insights into CMT, with the potential translation to advances in subcellular nanobiology.
  • Aqueous phase-synthesized small CdSe quantum dots: adsorption layer structure and strong band-edge and surface trap emission
    Yeon-Su Park, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Journal of Nanoparticle Research, 13, 11, 5781, 5798, SPRINGER, 2011年11月, [査読有り]
    英語, 研究論文(学術雑誌), We synthesized, in aqueous solution at room temperature, small water-soluble CdSe quantum dots (QDs) with strong photoluminescence (PL) and then correlated the PL with their adsorption layer structure. For synthesizing the QDs, their initial synthesis condition was controlled to form small Cd-containing species capable of passivating dangling bonds on the CdSe core surface. Each CdSe QD (d similar to 2.5 nm) consisted of a CdSe core (d similar to 2.1 nm), a cysteine (cys)-ligand shell, and an adsorption layer composed of Cd-cys complexes (mainly CdL(-H)(-), cys a parts per thousand H2L), cys (as L2-), Cd(OH)(2), and CdO (x) (x a parts per thousand yen 1). Our CdSe QDs showed strong blue band-edge PL as well as strong green surface trap PL. Their PL quantum yield (QY) of similar to 18% was unexpectedly high, considering their extremely small core size and their absence of any wide-bandgap inorganic shell. We attributed the QY to their adsorption layer species. The small weakly charged Cd-cys complex and the small neutral cadmium oxides in the adsorption layer could relatively readily diffuse into the unprotected surface sites on the core. These wide-bandgap species coalesced selectively on the unprotected surface sites with minimal spatial disturbance to the preexisting surface Cd-ligand coordination, and passivated them effectively. These decreased nonradiative recombination of the excitons significantly and thus led to the unexpectedly high QYs.
  • Extraction of Am(III) at the Interface of Organic-Aqueous Two-Layer Flow in a Microchannel
    Yasutoshi Ban, Yoshikuni Kikutani, Manabu Tokeshi, Yasuji Morita
    Journal of Nuclear Science and Technology, 48, 10, 1313, 1318, TAYLOR & FRANCIS LTD, 2011年10月, [査読有り]
    英語, 研究論文(学術雑誌), Extraction of Am(III) was performed at the interface of organic-aqueous two-layer flow in a microchannel having an asymmetric cross section. A solution of 3 mol/dm(3) nitric acid containing Am-243(III) and octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphineoxide diluted with n-dodecane were introduced into the microchannel as the aqueous phase and organic phase, respectively. The two phases formed a stable two-layer flow with an interface parallel to the sidewall of the microchannel, and they were separated from each other at the divergence point of the microchannel. The extraction reaction of Am(III) proceeded at the interface of the two phases, and reached the equilibrium state while the two phases passed through the microchannel.
  • A clinical trial for therapeutic drug monitoring using microchip-based fluorescence polarization immunoassay
    Tomoya Tachi, Tetsunari Hase, Yukihiro Okamoto, Noritada Kaji, Takeshi Arima, Hiroyuki Matsumoto, Masashi Kondo, Manabu Tokeshi, Yoshinori Hasegawa, Yoshinobu Baba
    Analytical and Bioanalytical Chemistry, 401, 7, 2301, 2305, SPRINGER HEIDELBERG, 2011年10月, [査読有り]
    英語, 研究論文(学術雑誌), Microchip analysis is a promising method for therapeutic drug monitoring. This led us to evaluate a microchip-based fluorescence polarization immunoassay (FPIA) system for point-of-care testing on patients being treated with theophylline. The sera were collected from 20 patients being treated with theophylline. Fluorescence polarization was measured on the microchip and theophylline concentrations in serum were obtained. Regression analysis of the correlations was done between the results given by the microchip-based FPIA and the conventional cloned enzyme donor immunoassay (CEDIA), and between the results given by the microchip-based FPIA and the conventional particle-enhanced turbidimetric inhibition immunoassay (PETINIA). We successfully carried out a quantitative analysis of theophylline in serum at values near its therapeutic range in 65 s. The results obtained by the microchip-based FPIA correlated well with CEDIA and PETINIA results; the correlation coefficients (R-2) were 0.986 and 0.989, respectively. The FPIA system is a simple and rapid method for point-of-care testing of drugs in serum, and its accuracy is the same as the conventional CEDIA and PETINIA. It is essential to use real samples from patients and to confirm good correlations with conventional methods for a study on the realization of microchip.
  • Electroosmotic Flow in Microchannels with Nanostructures
    Takao Yasui, Noritada Kaji, Mohamad Reza Mohamadi, Yukihiro Okamoto, Manabu Tokeshi, Yasuhiro Horiike, Yoshinobu Baba
    ACS Nano, 5, 10, 7775, 7780, AMER CHEMICAL SOC, 2011年10月, [査読有り]
    英語, 研究論文(学術雑誌), Here we report that nanopillar array structures have an Intrinsic ability to suppress electroosmotic flow (EOF). Currently using glass chips for electrophoresis requires laborious surface coating to control EOF, which works as a counterflow to the electrophoresis mobility of negatively charged samples such as DNA and sodium dodecyl sulfate (SDS) denatured proteins. Due to the Intrinsic ability of the nanopillar array to suppress the EOF, we carried out electrophoresis of SDS-protein complexes In nanopillar chips without adding any reagent to suppress protein adsorption and the EOF. We also show that the EOF profile inside a nanopillar region was deformed to an inverse parabolic flow. We used a combination of EOF measurements and fluorescence observations to compare EOF in microchannel, nanochannel, and nanopillar array chips. Our results of EOF measurements in micro- and nanochannel chips were in complete agreement with the conventional equation of the EOF mobility (mu(EOF-channel) = alpha C-i(-0.5), where C-i is the bulk concentration of the i-ions and alpha differs in micro- and nanochannels), whereas EOF in the nanopillar chips did not follow this equation. Therefore we developed a new modified form of the conventional EOF equation, mu(EOF-nanopillar) approximate to beta[C-i -(C-i(2)/N-i)], where N-i is the number of sites available to i-ions and beta differs for each nanopiliar chip because of different spacings or patterns, etc. The modified equation of the EOF mobility that we proposed here was in good agreement with our experimental results. In this equation, we showed that the charge density of the nanopiliar region, that is, the total number of nanopillars inside the microchannel, affected the suppression of EOF, and the arrangement of nanopillars into a tilted or square array had no effect on it.
  • DNA Separation in Nanowall Array Chips
    Takao Yasui, Noritada Kaji, Ryo Ogawa, Shingi Hashioka, Manabu Tokeshi, Yasuhiro Horiike, Yoshinobu Baba
    Analytical Chemistry, 83, 17, 6635, 6640, AMER CHEMICAL SOC, 2011年09月, [査読有り]
    英語, 研究論文(学術雑誌), A nanowall array structure was fabricated on a quartz chip as a separation matrix of DNA fragments, and a 30 s separation was realized for a mixture of DNA fragments (48.5 and 1 kbp fragments) by applying the electric voltage. A longer DNA fragment migrates faster than a shorter one in a nanowall array chip, and it is completely different from the separation of DNA based on gel electrophoresis, nanopillar chips, and nanoparticle array chips. Although the result is similar to DNA separation by entropic trapping, it could not be fully explained by entropic trapping phenomena. Direct observation of single-DNA molecular dynamics inside a nanowall array structure indicates that both confined elongation and relaxation recoiling of a DNA molecule occur, and an elongated DNA molecule migrates faster than a recoiled DNA molecule. Numerical fitting of DNA molecular dynamics reveals that the balance between times for the transverse of a DNA molecule in the nanowall array chip and the relaxation-recoiling of a DNA molecule governs the separation of DNA.
  • ナノ構造体を用いた無標識検出
    安井 隆雄, 加地 範匡, 岡本 行広, 渡慶次 学, 堀池 靖浩, 馬場 嘉信
    電気学会研究会資料. BMS, バイオ・マイクロシステム研究会 = The papers of Technical Meeting on Bio Micro Systems, IEE Japan, 2011, 8, 43, 45, 2011年06月30日
    日本語
  • Label-Free Detection of DNA-Binding Proteins Based on Microfluidic Solid-State Molecular Beacon Sensor
    Jun Wang, Daisuke Onoshima, Michihiko Aki, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Analytical Chemistry, 83, 9, 3528, 3532, AMER CHEMICAL SOC, 2011年05月, [査読有り]
    英語, 研究論文(学術雑誌), A solid-state molecular beacon using a gold support as a fluorescence quencher is combined with a polydimethylsiloxane (PDMS) microfluidic channel to construct an optical sensor for detecting single-stranded DNA binding protein (SSBP) and histone protein. The single-stranded DNA-Cy3 probe or double-stranded DNA-Cy3 probe immobilized on the gold surface is prepared for the detection of SSBP or histone, respectively. Due to the different quenching ability of gold to the immobilized single-stranded DNA-Cy3 probe and the immobilized double-stranded DNA-Cy3 probe, low fluorescence intensity of the attached single-stranded DNA-Cy3 is obtained in SSBP detection, whereas high fluorescence intensity of the attached double-stranded DNA-Cy3 is obtained in histone detection. The amounts of SSBP in sample solutions are determined from the degree of fluorescence recovery of the immobilized single-stranded DNA-Cy3 probe, whereas that of histone in sample solutions is determined from the degree of fluorescence quenching of the immobilized double-stranded DNA-Cy3 probe. Using this approach, label-free detection of target proteins at nanomolar concentrations is achieved in a convenient, general, continuous flow format. Our approach has high potential for the highly sensitive label-free detection of various proteins based on binding-induced conformation changes of immobilized DNA probes.
  • マイクロTAS技術の最新動向
    渡慶次 学
    電気学会誌 = The journal of the Institute of Electrical Engineers of Japan, 131, 5, 296, 299, The Institute of Electrical Engineers of Japan, 2011年05月01日
    日本語, 本記事に「抄録」はありません。
  • Trafficking and Subcellular Localization of Multiwalled Carbon Nanotubes in Plant Cells
    Maged F. Serag, Noritada Kaji, Claire Gaillard, Yukihiro Okamoto, Kazuyoshi Terasaka, Mohammad Jabasini, Manabu Tokeshi, Hajime Mizukami, Alberto Bianco, Yoshinobu Baba
    ACS Nano, 5, 1, 493, 499, AMER CHEMICAL SOC, 2011年01月, [査読有り]
    英語, 研究論文(学術雑誌), Major barriers to delivery of biomolecules are crossing the cellular membranes and achieving a., high cytoplasmic concentration by circumventing entrapment into endosomes and other lytic organelles. Motivated by such aim, we have investigated the capability of multiwalled carbon nanotubes (MWCNTs) to penetrate the cell membrane of plant protoplasts (plant cells made devoid of their cell walls via enzymatic, treatment) and studied their internalization mechanism via confocal imaging and TEM techniques. Our results indentified an endosome-escaping uptake mode of MWCNTs by plant protoplasts. Moreover, short MWCNTs (<100. nm) were observed to target specific cellular substructures including the nucleus, plastids, and vacuoles. These, findings are expected to have a significant impact on plant cell biology and transformation technologies.
  • Online transient isotachophoresis concentration by the pseudo-terminating electrolyte buffer for the separation of DNA-aptamer and its thrombin complex in poly(methyl methacrylate) microchip
    Jun Wang, Yong Zhang, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Analyst, 136, 6, 1142, 1147, ROYAL SOC CHEMISTRY, 2011年, [査読有り]
    英語, 研究論文(学術雑誌), Online automatic transient isotachophoresis concentration of DNA-aptamer and its thrombin complex by using one kind of pseudo-terminating electrolyte buffer in a cross-channel poly(methyl methacrylate) microchip is reported. Sample injection, transient concentration and separation were done continuously and controlled by a sequential voltage switching program, time-consuming steps and complicated chip design were not required. Peak resolution between DNA-aptamer and its thrombin complex was influenced by this novel pseudo-terminating electrolyte buffer, which was prepared by the addition of chemical component with slow mobility into the same buffer as leading electrolyte buffer. 1100-fold signal enhancement of thrombin complex was achieved by this transient isotachophoresis on a standard cross-form microchip. The concentration effect or standing time of transient isotachophoresis was proved to be influenced by the concentration of leading electrolyte ion and the concentration of pseudo-terminating electrolyte buffer ion (glycine). The transient concentration was followed by on-chip nondenaturing gel electrophoresis in methylcellulose solution for the size-based separation. The detection limit, taken as the lowest thrombin concentration at threefold S/N, was determined to be 0.5 amol in mass by this method.
  • Thermal lens detection device
    Kazuma Mawatari, Toshinori Ohashi, Tomohiko Ebata, Manabu Tokeshi, Takehiko Kitamori
    Lab on a Chip, 11, 17, 2990, 2993, ROYAL SOC CHEMISTRY, 2011年, [査読有り]
    英語, 研究論文(学術雑誌), A thermal lens detection device was developed to realize an easy-to-use, portable and sensitive detector for nonfluorescent molecules. Two laser diodes (658 nm for excitation and 785 nm for probe) were made coaxial in an optical unit and were coupled to a single-mode optical fiber. On a microfluidic chip, a small holder for the optical fiber was fixed, and micro-lenses (numerical aperture of 0.2) were also integrated inside the holder. The micro-lenses were designed to realize an adequate chromatic aberration (50 mm), which was essential for sensitive thermal lens detection. Compared with conventional thermal lens detection systems which required very laborious and accurate optical alignment with the microchannel, the new device needed just attachment-detachment of the optical fiber, which was important for practical application. The lower limit of detection was 10 nM for nickel (II) phthalocyaninetetrasulfonic acid tetrasodium salt solutions (model sample), and the absorbance was 9 x 10(-6) AU. The absolute number of molecules detected was less than 200 zmol. The coefficient of variance for 5-time attachment-detachment of the optical probe was as small as 3.6%. The technical development allowed integration of the thermal lens detection devices inside a microsystem (e. g. enzyme-linked immuno-sorbent assay system), and practical microsystems were realized with sensitivities several-orders higher than absorptiometry.
  • A touch-and-go lipid wrapping technique in microfluidic channels for rapid fabrication of multifunctional envelope-type gene delivery nanodevices
    Katsuma Kitazoe, Jun Wang, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Kentaro Kogure, Hideyoshi Harashima, Yoshinobu Baba
    Lab on a Chip, 11, 19, 3256, 3262, ROYAL SOC CHEMISTRY, 2011年, [査読有り]
    英語, 研究論文(学術雑誌), Multifunctional envelope-type gene delivery nanodevices (MENDs) are promising non-viral vectors for gene therapy. Though MENDs remain strong in prolonged exposure to blood circulation, have low immunogenic response, and are suitable for gene targeting, their fabrication requires labor-intensive processes. In this work, a novel approach has been developed for rapid fabrication of MENDs by a touch-and-go lipid wrapping technique in a polydimethylsiloxane (PDMS)/glass microfluidic device. The MEND was fabricated on a glass substrate by introduction of a condensed plasmid DNA core into microfluidic channels that have multiple lipid bilayer films. The principle of the MEND fabrication in the microfluidic channels is based on electrostatic interaction between the condensed plasmid DNA cores and the coated lipid bilayer films. The constructed MEND was collected off-chip and characterized by dynamic light scattering. The MEND was constructed within 5 min with a narrow size distribution centered around 200 nm diameter particles. The size of the MEND showed strong dependence on flow velocity of the condensed plasmid DNA core in the microfluidic channels, and thus, could be controlled to provide the optimal size for medical applications. This approach was also proved possible for fabrication of a MEND in multiple channels at the same time. This on-chip fabrication of the MEND was very simple, rapid, convenient, and cost-effective compared with conventional methods. Our results strongly indicated that MENDs fabricated with our microfluidic device have a good potential for medical use. Moreover, MENDs fabricated by this microfluidic device have a great potential for clinical use because the devices are autoclavable and all the fabrication steps can be completed inside closed microfluidic channels without any external contamination.
  • Microfluidic baker's transformation device for three-dimensional rapid mixing
    Takao Yasui, Yusuke Omoto, Keiko Osato, Noritada Kaji, Norikazu Suzuki, Toyohiro Naito, Masaki Watanabe, Yukihiro Okamoto, Manabu Tokeshi, Eiji Shamoto, Yoshinobu Baba
    Lab on a Chip, 11, 19, 3356, 3360, ROYAL SOC CHEMISTRY, 2011年, [査読有り]
    英語, 研究論文(学術雑誌), We developed a new passive-type micromixer based on the baker's transformation and realized a fast mixing of a protein solution, which has lower diffusion constant. The baker's transformation is an ideal mixing method, but there is no report on the microfluidic baker's transformation (MBT), since it is required to fabricate the complicated three-dimensional (3D) structure to realize the MBT device. In this note, we successfully fabricate the MBT device by using precision diamond cutting of an oxygen-free copper substrate for the mould fabrication and PDMS replication. TheMBTdevice with 10.4 mm mixing length enables us to achieve complete mixing of a FITC solution (D = 2.6 x 10(-10) m(2) s(-1)) within 51 ms and an IgG solution (D = 4.6 x 10(-11) m(2) s(-1)) within 306 ms. Its mixing speed is 70-fold higher for a FITC solution and 900-fold higher for an IgG solution than the mixing speed by the microchannel without MBT structures. The Peclet number to attain complete mixing in the MBT device is estimated to be 6.9 x 10(4).
  • 紙を使った分析・診断チップの現状と可能性
    渡慶次 学
    機能紙研究会誌, 50, 43, 46, 特定非営利活動法人 機能紙研究会, 2011年
    日本語, Recently, paper-based microfluidic chips have received much attention. These chips are categorized as a new class of point-of-care diagnostic devices that are cheap, easy-to-use, and designed on demand in developing countries. In this paper, we review the fabrication methods, the operation procedures, and the detection methods of paper-based microfluidic chips. Moreover, we describe the present situation and future possibility of paper-based microfluidic chips.
  • A DNA size probe based on energy migration in crosslinked chromatin
    Maged F. Serag, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yoshinobu Baba
    15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011, MicroTAS 2011, 1, 58, 60, 2011年, [査読有り]
    研究論文(国際会議プロシーディングス), DNA sizing has a central role in virtually every aspect of physical genomic analysis. Although capillary gel electrophoresis adequately separates DNA samples, accurate sizing of short sequences is problematic. Here we introduce a simple methodology that affords sizing of short DNA sequences at 2nt resolution via wrapping and linking histone subunits with fluorophore-tagged ssDNA to extract a wrapping and linking ratio that is unique to the reported DNA size. Copyright © (2011) by the Chemical and Biological Microsystems Society.
  • Aqueous Phase Synthesized CdSe Nanoparticles with Well-Defined Numbers of Constituent Atoms
    Yeon-Su Park, Andriy Dmytruk, Igor Dmitruk, Atsuo Kasuya, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Journal of Physical Chemistry C, 114, 44, 18834, 18840, AMER CHEMICAL SOC, 2010年11月, [査読有り]
    英語, 研究論文(学術雑誌), We report aqueous phase synthesized semiconductor nanoparticles with well-defined numbers of constituent atoms. Aqueous phase synthesis provides many advantages over organic phase synthesis for producing such high-quality semiconductor nanoparticles. We synthesized CdSe nanoparticles with excellent colloidal and optical stabilities directly in aqueous solution at room temperature and then identified them as selectively grown (CdSe)(33) and (CdSe)(34) magic-sized clusters. These clusters displayed extremely sharp excitonic absorption and emission peaks because of their practically monodispersed size distribution. Their X-ray diffraction pattern and Raman spectral features were considerably different from the corresponding pattern and features for typical crystalline CdSe nanoparticles. Growth of our magic-sized clusters was very slow and proceeded via the formation of different sizes of progressively larger CdSe nanoparticle intermediates with time. Our results demonstrated that aqueous phase synthetic routes could be successfully adopted for producing high-quality semiconductor nanoparticles.
  • DNA separation by cholesterol-bearing pullulan nanogels
    Keisuke Kondo, Noritada Kaji, Sayaka Toita, Yukihiro Okamoto, Manabu Tokeshi, Kazunari Akiyoshi, Yoshinobu Baba
    Biomicrofluidics, 4, 3, 032210-1, 10, AMER INST PHYSICS, 2010年09月, [査読有り]
    英語, 研究論文(学術雑誌), We present an application of a novel DNA separation matrix, cholesterol-bearing pullulan (CHP) nanogels, for microchip electrophoresis. The solution of the CHP showed a unique phase transition around 30 mg/ml and formed gel phase over this critical concentration. This gel phase consists of the weak hydrophobic interactions between the cholesterols could be easily deformed by external forces, and thus, loading process of the CHP nanogels into microchannels became easier. The high concentration of the CHP nanogels provided excellent resolutions especially for small DNA fragments from 100 to 1500 bp. The separation mechanism was discussed based on Ogston and Reptation models which had developed in gels or polymer solutions. The result of a single molecule imaging gave us an insight of the separation mechanism and the nanogel structures as well. (C) 2010 American Institute of Physics. [doi:10.1063/1.3479997]
  • ナノピラー構造体が電気浸透流に及ぼす影響の評価
    安井 隆雄, 加地 範匡, 岡本 行広, 渡慶次 学, 堀池 靖浩, 馬場 嘉信
    電気学会研究会資料. BMS, バイオ・マイクロシステム研究会 = The papers of Technical Meeting on Bio Micro Systems, IEE Japan, 2010, 7, 33, 35, 2010年06月18日
    日本語
  • Quantum dots labeling using octa-arginine peptides for imaging of adipose tissue-derived stem cells
    Hiroshi Yukawa, Yukimasa Kagami, Masaki Watanabe, Koichi Oishi, Yoshitaka Miyamoto, Yukihiro Okamoto, Manabu Tokeshi, Noritada Kaji, Hirofumi Noguchi, Kenji Ono, Makoto Sawada, Yoshinobu Baba, Nobuyuki Hamajima, Shuji Hayashi
    Biomaterials, 31, 14, 4094, 4103, ELSEVIER SCI LTD, 2010年05月, [査読有り]
    英語, 研究論文(学術雑誌), Quantum dots (QDs) have been used to study the effects of fluorescent probes for biomolecules and cell imaging. Adipose tissue-derived stem cells, which carry a relatively lower donor site morbidity, while yielding a large number of stem cells at harvest, were transduced with QDs using the octa-arginine peptide (R8) cell-penetrating peptide (CPP). The concentration ratio of QDs:R8 of 1 x 10(4) was optimal for delivery into ASCs. No cytotoxicity was observed in ASCs transduced with less than 16 nM of QDs655. In addition, >80% of the cells could be labeled within 1 h and the fluorescent intensity was maintained at least for 2 weeks. The ASCs transduced with QDs using R8 could be differentiated into both adipogenic and osteogenic cells, thus suggesting that the cells maintained their stem cell potency. The ASCs labeled with QDs using R8 were further transplanted subcutaneously into the backs of mice or into mice through the tail vein. The labeled ASCs could be imaged with good contrast using the Maestro in vivo imaging system. These data suggested that QD labeling using R8 could be utilized for the imaging of ASCs. (C) 2010 Elsevier Ltd. All rights reserved.
  • Nanopillar, nanoball, and nanofibers for highly efficient analysis of biomolecules.
    Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yoshinobu Baba
    Chemical Society Reviews, 39, 3, 948, 56, 2010年03月, [国際誌]
    英語, 研究論文(その他学術会議資料等), DNA separation technologies combined with micro- and nanofabrication technologies found a breakthrough in genotyping and DNA sequencing. This tutorial review outlines the fabrication technologies for nano-scaled structures inside microchannels and how the precisely designed structures contribute to obtaining higher performances in DNA separations from the viewpoint of the fabrication process, "top-down" nanofabrication and "bottom-up" molecular self-assembly approaches. It was found that these nanofabricated structures generated the unique separation modes that could not be achieved by random-sized pores of conventional gel or polymer systems. Furthermore, it was found that nanoscale-specific phenomena such as electroosmotic flow should be taken into consideration for further development of nanofabricated structures in DNA analysis. These separation technologies will contribute as a core technology for a future integrated biomolecule anlaysis chip.
  • A Probe Containing Two Base-discriminating Fluorescent (BDF) Nucleosides for SNP Typing
    Yasuko Yoshida, Kousuke Niwa, Kazunari Yamada, Manabu Tokeshi, Yoshinobu Baba, Yoshio Saito, Akimitsu Okamoto, Isao Saito
    Chemistry Letters, 39, 2, 116, 117, CHEMICAL SOC JAPAN, 2010年02月, [査読有り]
    英語, 研究論文(学術雑誌), We have developed a new probe containing two base-discriminating fluorescent (BDF) nucleosides for single nucleotide polymorphism (SNP) typing. It is possible to determine the SNP type using just one probe. We confirmed suitability of the probe from hybridization assay results obtained for the ALDH2 gene.
  • Size-Selective Growth and Stabilization of Small CdSe Nanoparticles in Aqueous Solution
    Yeon-Su Park, Andriy Dmytruk, Igor Dmitruk, Atsuo Kasuya, Motohiro Takeda, Noriaki Ohuchi, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    ACS Nano, 4, 1, 121, 128, AMER CHEMICAL SOC, 2010年01月, [査読有り]
    英語, 研究論文(学術雑誌), Using cysteine and its derivatives as capping molecules, we investigated the influence of the physical structure and chemical nature of capping molecules on the selective growth and stabilization of small CdSe nanoparticles (NPs) in aqueous solution at. room temperature. Our investigations revealed specific roles for each functional group of cysteine, and we could correlate this structure and nature of the capping molecules with the size, size restriction, size distribution, and stability of the NPs. For selective growth and stabilization of the NPs in aqueous solution, their capping molecules should have at least one functional group with strong nucleophilicity as well as another free, charged functional group. Capping molecules acting as a monodentate ligand were more effective than those acting as a bidentate ligand for restricting the NPs to a smaller size, whereas the former was less effective than the latter for getting a narrower NP size distribution. Capping molecules with relatively bulky spatial geometry near the ligand-NP interface resulted In the formation of NPs with poor short and long-term stabilities, whereas those having relatively compact spatial geometry near the interface led to NIPS with at least moderate short-term stability. We saw that capping molecules having relatively compact outermost spatial geometry led to NPs with, excellent long-term stability, whereas those having relatively bulky outermost spatial geometry produced NPs with at most only moderate long-term stability. Our results dearly showed general trends for the possibility of selective growth of stable semiconductor NPs with particular sizes in aqueous solution.
  • 培養チップとアッセイチップを組み合わせた簡便なハイスループット細胞アッセイシステムの開発
    杉浦 佳奈子, 加地 範匡, 岡本 行広, 渡慶次 学, 馬場 嘉信
    電気学会論文誌. E, センサ・マイクロマシン部門誌, 130, 10, 471, 475, 一般社団法人 電気学会, 2010年, [査読有り]
    日本語, 研究論文(学術雑誌), High throughput cell assay is significantly important in drug screening, assessment of toxicity etc. Cell assay with a microchip is one of the candidates for high throughput cell assay. However, reported cell assay system with the microchip requires expensive apparatus for refluxing medium and investigation of optimum experimental condition for steady data. For an inexpensive, easy and high throughput cell assay, we introduce a new cell assay system combined with a culture chip and an assay chip made of poly(dimethyl siloxane). Cell culture chips enabled cell to proliferate along the microchannel without refluxing medium and permitted to prepare cell patterning easily. Also, assay chips formed concentration gradient inside the chip and allowed the cell assay with different concentrations of drug at the same time. Thus, our developed cell assay system can overcome the problems of the present cell assay and would promote the drug discovery, assessment of toxicity etc.
  • Immuno-pillar chip: a new platform for rapid and easy-to-use immunoassay
    Mai Ikami, Ayako Kawakami, Masaya Kakuta, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Lab on a Chip, 10, 24, 3335, 3340, ROYAL SOC CHEMISTRY, 2010年, [査読有り]
    英語, 研究論文(学術雑誌), We present a new rapid and easy-to-use immunoassay chip which we have named the immuno-pillar chip. It has hydrogel pillars, fabricated inside a microchannel, with many antibody molecules immobilized onto 1 mu m diameter polystyrene beads. To evaluate the chip performance, we applied it to the sandwich assay of C-reactive protein (CRP), alpha-fetoprotein (AFP) and prostate-specific antigen (PSA), a cardiac and inflammation marker, tumors and prostate cancer markers, respectively. For detection of disease markers, we confirmed the chip provides rapid analysis (total assay time of about 4 min) with high sensitivity, it is easy-to-use (no special skills are needed), and it uses small volumes of the sample and reagent (0.25 mu L each). Moreover, multiplex assay for three biomarkers was also possible. Additionally, the immuno-pillar chip has a big advantage of having hardly any influence on the assay results even if the introduction quantities of the sample or reagents are different.
  • 電気学会論文誌E
    加地 範匡, 渡慶次 学, 馬場 嘉信
    130巻, 471, 475, 2010年, [査読有り]
    研究論文(学術雑誌)
  • Nano-fabricated structures for biomolecule analysis
    Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yoshinobu Baba
    Bio-Inspired Nanomaterials and Nanotechnology, 41, 58, 2010年01月01日, [査読有り]
    論文集(書籍)内論文, © 2010 Nova Science Publishers, Inc. In this chapter, the recent development of biomolecule analysis, especially biomolecule separation using nano-fabricated structures was reviewed. Fundamental fabrication techniques for micro- and nano-structures on silicon or glass substrates, various approaches for biomolecule separation based on different separation mechanisms, and typical applications such as DNA separation will be included, and practical applications such as DNA separation are described from the aspect of ?nanomaterials and nanotechnology for bio-analytical chemistry.
  • Exceeding 20 000-fold concentration of protein by the on-line isotachophoresis concentration in poly(methyl methacrylate) microchip
    Jun Wang, Yong Zhang, Molhamad Reza Mohamadi, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Electrophoresis, 30, 18, 3250, 3256, WILEY-BLACKWELL, 2009年09月, [査読有り]
    英語, 研究論文(学術雑誌), In this research, a simple on-line microchip gel electrophoresis with ITP was applied for the concentration and separation of BSA and its immunoassay complex with mAb in a single cross form PMMA microchip. We investigated the ITP concentration effect in PMMA MCE using combination of leading electrolytes, terminating electrolytes and other factors. We realized an ITP-based concentration and separation of BSA and its immunoassay complexes in standard cross-channel microchip gel electrophoresis, which exceeded 2000-fold concentration of BSA immunocomplex using Tris-H3PO4 as a leading electrolyte and Tris-gamma-amino butyric acid as a terminating electrolyte. in addition, we also realized concentration of BSA sample in water, which was more than 20 000-fold and was the result of the concentration effect from combining ITP and the sample stacking techniques.
  • Cell separation by the combination of microfluidics and optical trapping force on a microchip
    Masaya Murata, Yukihiro Okamoto, Yeon-Su Park, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Analytical and Bioanalytical Chemistry, 394, 1, 277, 283, SPRINGER HEIDELBERG, 2009年05月, [査読有り]
    英語, 研究論文(学術雑誌), We investigated properties of cells affecting their optical trapping force and successfully established a novel cell separation method based on the combined use of optical trapping force and microfluidics on a microchip. Our investigations reveal that the morphology, size, light absorption, and refractive index of cells are important factors affecting their optical trapping force. A sheath flow of sample solutions created in a microchip made sample cells flow in a narrow linear stream and an optical trap created by a highly focused laser beam captured only target cells and altered their trajectory, resulting in high-efficiency cell separation. An optimum balance between optical trapping force and sample flow rate was essential to achieve high cell separation efficiency. Our investigations clearly indicate that the on-chip optical trapping method allows high-efficiency cell separation without cumbersome and time-consuming cell pretreatments. In addition, our on-chip optical trapping method requires small amounts of sample and may permit high-throughput cell separation and integration of other functions on microchips.
  • Microchip-based homogeneous immunoassay using fluorescence polarization spectroscopy.
    Tomoya Tachi, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Lab on a Chip, 9, 7, 966, 71, 2009年04月07日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), We have realized fluorescence polarization immunoassay (FPIA) on a microchip in about 1 minute. FPIA is a homogeneous competitive immunoassay which is based on measuring fluorescence polarization after competitive binding of an analyte and a tracer to an antibody. We constructed a microfluidic FPIA system composed of a newly designed microchip, a laser, a CCD camera and an optical microscope with two specially installed polarizers-one fixed and one rotatable. Theophylline, a typical small drug molecule, was used as a model analyte. Theophylline and fluorescence-labeled theophylline were introduced through different inlets and combined in a 100 microm-wide microchannel where anti-theophylline antibody was added. To optimize the microchip design for FPIA, we investigated the diffusion time of theophylline and the mixing time of theophylline and antibody in this channel, which were 6 s and 36 s, respectively. We successfully carried out a quantitative analysis of theophylline in serum near the therapeutic range in 65 s. In FPIA, a larger tracer-antibody complex emits more polarized fluorescence than the tracer, and therefore, by increasing the antigen concentration in a sample, more polarization relaxation is observed since the tracer-antibody complex concentration is decreased and the tracer concentration is increased. Tracer binding to an antibody is directly measured by spectroscopic techniques without any separation process.This microchip-based FPIA is very simple and rapid, unlike microchip-based heterogeneous immunoassay, because it does not require several processes such as washing and reflowing and immobilizing of antibodies or antigens in the channel. In the future, microchip-based FPIA should find frequent use for point-of-care testing in the clinical field, where conventional FPIA has been used for laboratory tests.
  • Simultaneous Separation, Metering, and Dilution of Plasma from Human Whole Blood in a Microfluidic System
    Tomoya Tachi, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Analytical Chemistry, 81, 8, 3194, 3198, AMER CHEMICAL SOC, 2009年04月, [査読有り]
    英語, 研究論文(学術雑誌), In about a 3 min period, we have simultaneously separated plasma from human whole blood and metered and diluted the plasma using a microchip with an interchannel microstructure. The plasma separation was based on both cross-flow filtration and sedimentation of red blood cells in the microchannels. Metering and diluting operations of the plasma were based on volume control of liquid in the microchannels by syringe pumps. On this microchip, we produced plasma diluted by a factor of 6 from whole blood containing theophylline and we observed very little hemolysis. It is possible to separate plasma from one or just several drops of whole blood by using this microchip.
  • Phase separation of gas-liquid and liquid-liquid microflows in microchips
    Arata Aota, Kazuma Mawatari, Susumu Takahashi, Teruki Matsumoto, Kazuteru Kanda, Ryo Anraku, Akihide Hibara, Manabu Tokeshi, Takehiko Kitamori
    Microchimica Acta, 164, 3-4, 249, 255, SPRINGER WIEN, 2009年03月, [査読有り]
    英語, 研究論文(学術雑誌), Phase separation of gas-liquid and liquid-liquid microflows in microchannels were examined and characterized by interfacial pressure balance. We considered the conditions of the phase separation, where the phase separation requires a single phase flow in each output of the microchannel. As the interfacial pressure, we considered the pressure difference between the two phases due to pressure loss in each phase and the Laplace pressure generated by the interfacial tension at the interface between the separated phases. When the pressure difference between the two phases is balanced by the Laplace pressure, the contact line between the two phases is static. Since the contact angle characterizing the Laplace pressure is restricted to values between the advancing and receding contact angles, the Laplace pressure has a limit. When the pressure difference between the two phases exceeds the limiting Laplace pressure, one of the phases leaks into the output channel of the other phase, and the phase separation fails. In order to experimentally verify this physical picture, microchips were used having a width of 215 mu m and a depth of 34 mu m for the liquid-liquid microflows, a width of 100 mu m and a depth of 45 mu m for the gas-liquid microflows. The experimental results of the liquid-liquid microflows agreed well with the model whilst that of the gas-liquid microflows did not agree with the model because of the compressive properties of the gas phase and evaporation of the liquid phase. The model is useful for general liquid-liquid microflows in continuous flow chemical processing.
  • Microchip-based homogeneous immunoassay using a cloned enzyme donor.
    Tomoya Tachi, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Analytical Sciences, 25, 2, 149, 51, 2009年02月, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌), We have realized a cloned enzyme donor immunoassay (CEDIA) on a microchip in 96 s. CEDIA is a homogeneous immunoassay, based on the bacterial enzyme beta-galactosidase, which was genetically engineered into two inactive fragments: an enzyme donor and an enzyme acceptor. A model analyte was theophylline, and the detectable concentration range was from 0 to 40 microg mL(-1). Our CEDIA using a microfluidic device was very simple and rapid, unlike microchip-based heterogeneous immunoassays and CEDIA on a well-type microchip.
  • A micro-ELISA system for the rapid and sensitive measurement of total and specific immunoglobulin E and clinical application to allergy diagnosis
    Toshinori Ohashi, Kazuma Mawatari, Kae Sato, Manabu Tokeshi, Takehiko Kitamori
    Lab on a Chip, 9, 7, 991, 995, ROYAL SOC CHEMISTRY, 2009年, [査読有り]
    英語, 研究論文(学術雑誌), We have developed a novel, practical micro-ELISA system for sensitive and rapid allergy diagnosis. The enzymatic reactions occurred under stopped-flow conditions, resulting in both high precision and high sensitivity. A BSA-biotin-avidin linker was introduced for the immobilization of water-soluble allergens on polystyrene microbeads, enabling immobilization of allergens in sufficient density to provide high sensitivity. Evaluation of the system's performance showed a good detection limit (2 ng/mL) for total IgE measurement. In addition, a good correlation with a conventional method (CAP method) was demonstrated using human serum samples from 85 allergy patients. Importantly, sample volumes (5 mu L) were 10 times smaller and analysis time (12 min) was > 20 times faster than the conventional method. All procedures were automatically regulated with our simple microfluidic system, and all the fluidic, optic and electronic components were integrated for portability. We believe that our system has the potential to become a very powerful tool, particularly for point-of-care diagnosis.
  • Electroosmotic flow in nanopillar array structures
    Takao Yasui, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yasuhiro Horiike, Yoshinobu Baba
    Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 174, 176, 2009年, [査読有り]
    研究論文(国際会議プロシーディングス), In this paper, we found that ions in nanospace would be concentrated according to electric field gradient by using nanopillar array structures. Due to the ion-enrichment inside the nanopillar region, electroosmotic flow (EOF) in the nanopillar chip was suppressed dramatically. And also, we revealed that EOF suppression by ion-enrichment generated EOF profile deformation from a plug flow to an inverse parabolic flow. © 2009 CBMS.
  • Quantum Dots for Labeling Adipose Tissue-Derived Stem Cells
    Hiroshi Yukawa, Shogo Mizufune, Chiharu Mamori, Yukimasa Kagami, Koichi Oishi, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Hirofumi Noguchi, Yoshinobu Baba, Michinari Hamaguchi, Nobuyuki Hamajima, Shuji Hayashi
    Cell Transplantation, 18, 5-6, 591, 599, COGNIZANT COMMUNICATION CORP, 2009年
    英語, 研究論文(学術雑誌), Adipose tissue-derived stem cells (ASCs) have a self-renewing ability and can be induced to differentiate into various types of mesenchymal tissue. Because of their potential for clinical application, it has become desirable to label the cells for tracing transplanted cells and for in vivo imaging. Quantum dots (QDs) are novel inorganic probes that consist of CdSe/ZnS-core/shell semiconductor nanocrystals and have recently been explored as fluorescent probes for stem cell labeling. In this study, negatively charged QDs655 were applied for ASCs labeling, with the cationic liposome, Lipofectamine. The cytotoxicity of QDs655-Lipofectamine was assessed for ASCs. Although some cytotoxicity was observed in ASCs transfected with more than 2.0 nM of QDs655, none was observed with less than 0.8 nM. To evaluate the time dependency, the fluorescent intensity with QDs655 was observed until 24 h after transfection. The fluorescent intensity gradually increased until 2 h at the concentrations of 0.2 and 0.4 nM, while the intensity increased until 4 h at 0.8 nM. The ASCs were differentiated into both adipogenic and osteogenic cells with red fluorescence after transfection with QDs655, thus suggesting that the cells retain their potential for differentiation even after transfected with QDs655. These data suggest that QDs could be utilized for the labeling of ASCs.
  • Flow Analysis in Microfluidic Devices
    Manabu Tokeshi, Takehiko Kitamori
    Advances in Flow Analysis, 149, 166, Wiley-VCH Verlag GmbH & Co. KGaA, 2008年09月16日, [査読有り]
    英語, 論文集(書籍)内論文
  • Nanotechnologies in the biosciences
    Manabu Tokeshi, Yoshinobu Baba
    Analytical and Bioanalytical Chemistry, 391, 8, 2693, 2694, 2008年08月, [査読有り]
    研究論文(学術雑誌)
  • On-chip fabrication of mutifunctional envelope-type nanodevices for gene delivery
    Hiroshi Kuramoto, Yeon-Su Park, Noritada Kaji, Manabu Tokeshi, Kentaro Kogure, Yasuo Shinohara, Hideyoshi Harashima, Yoshinobu Baba
    Analytical and Bioanalytical Chemistry, 391, 8, 2729, 2733, SPRINGER HEIDELBERG, 2008年08月
    英語, 研究論文(学術雑誌), Microfluidic devices may be highly beneficial to the rapid fabrication of small quantities of various nonviral vectors with different functionalities, which is indispensable for effective order-made gene therapy. We adapted a microfluidic chip-based approach for fabricating small quantities of nonviral vectors in a short time in preparation for order-made gene therapy applications. This approach permitted us to fabricate multifunctional envelope-type nanodevices (MENDs), composed of a compacted (or condensed) DNA core and a lipid bilayer membrane shell, which are considered as promising nonviral vectors for gene therapy applications. The on-chip fabrication of the MEND was very simple, rapid, convenient, and cost-effective compared with conventional methods. The size of the MEND showed strong dependence on the concentration and flow rate of the reaction precursors and could be controlled to be much smaller than that achievable by conventional methods. This, together with abovementioned merits, makes our microfluidic chip-based approach very attractive for the fabrication of MENDs for effective application to order-made gene therapy.
  • A viscosity-tunable polymer for DNA separation by microchip electrophoresis
    Daisuke Kuroda, Yong Zhang, Jun Wang, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Analytical and Bioanalytical Chemistry, 391, 7, 2543, 2549, SPRINGER HEIDELBERG, 2008年08月
    英語, 研究論文(学術雑誌), A thermo-responsive separation matrix, consisting of Pluronic F127 tri-block copolymers of poly(ethylene oxide) and poly(propylene oxide), was used to separate DNA fragments by microchip electrophoresis. At low temperature, the polymer matrix was low in viscosity and allowed rapid loading into a microchannel under low pressure. With increasing temperatures above 25C, the Pluronic F127 solution forms a liquid crystalline phase consisting of spherical micelles with diameters of 17-19 nm. The solution can be used to separate DNA fragments from 100 bp to 1500 bp on poly(methyl methacrylate) (PMMA) chips. This temperature-sensitive and viscosity-tunable polymer provided excellent resolution over a wide range of DNA sizes. Separation is based on a different mechanism compared with conventional matrices such as methylcellulose. To illustrate the separation mechanism of DNA in a Pluronic F127 solution, DNA molecular imaging was performed by fluorescence microscopy with F127 polymer as the separation matrix in microchip electrophoresis.
  • Flowing thermal lens micro-flow velocimeter
    Yoshikuni Kikutani, Kazuma Mawatari, Kenji Katayama, Manabu Tokeshi, Takashi Fukuzawa, Mitsuo Kitaok, Takehiko Kitamori
    Sensors and Actuators B-Chemical, 133, 1, 91, 96, ELSEVIER SCIENCE SA, 2008年07月, [査読有り]
    英語, 研究論文(学術雑誌), A novel micro-flow velocimeter, the flowing thermal lens micro-flow velocimeter (FTL-MFV) is developed in which a photothermally generated local refractive index change (a thermal lens) is utilized as a micro-tracer of flow. Flow velocity is measured from the time required for the thermal lens to travel between two points. Generation and detection of thermal lenses are carried out optically without contacting the flow. By choosing the wavelength of the excitation beam pulse so that it coincides with the absorption band of the solvent used, thermal lenses can be generated without adding anything to the liquid. Synchronous detection using a lock-in amplifier makes detection of thermal lens with a very small temperature rise possible. Thus, with the FTL-MFV, non-contact in situ measurement of flow can be carried out with only slight disturbance to the microfluid. In order to make the sensor small, optical fibers and SELFOC(TM) microlenses are used in focusing the excitation and probe beams. A dynamic range of 25-300 mu L/min is realized in measurement of flow rates in a microchannel. (C) 2008 Elsevier B.V. All rights reserved.
  • Highly sensitive double-fluorescent dye staining method on microchip electrophoresis for analysis of milk proteins
    Hiroki Okada, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Electrophoresis, 29, 12, 2533, 2538, WILEY-BLACKWELL, 2008年06月, [査読有り]
    英語, 研究論文(学術雑誌), We demonstrated a highly sensitive double-fluorescent dye staining in microchip electrophoresis (ME) for analysis of milk proteins. The detection sensitivity of ME was very limited so far and needed improvement. Our staining method consisted of two steps. First, in sample preparation before electrophoresis, protein was covalently bound to an amine-reactive fluorescent dye, Cy5. Then, the Cy5-attached protein was denatured with SDS and was further stained, during electrophoresis, with Agilent fluorescent dye, which was non-covalently attached to hydrophobic regions of the SDS-protein complexes. This double-fluorescent staining enhanced fluorescent intensity and lowered the detection limit to 200 pg of protein. This provided higher sensitivity than silver- or SYPRO Ruby-staining methods, which have previously given the highest sensitivity in protein staining. In addition, we applied our staining method to analysis of milk proteins and achieved their successful detection, whereas it was difficult to analyze them by the unimproved method.
  • Microchip analysis of plant glucosinolates
    Maged Fouad, Mohammad Jabasini, Noritada Kaji, Kazuyoshi Terasaka, Manabu Tokeshi, Hajime Mizukami, Yoshinobu Baba
    Electrophoresis, 29, 11, 2280, 2287, WILEY-BLACKWELL, 2008年06月, [査読有り]
    英語, 研究論文(学術雑誌), We describe a new and selective analytical method for the separation and quantitation of plant glucosinolates. The new method, which utilizes microchip CE (mu-CE) with fluorescence detection, circumvents the multistep procedures characteristic of conventional methods. Glucosinolates form charge transfer complexes with the xanthene dyes phloxine-B and eosin-B. The glucosinotates-phloxine-B complex cannot be excited at 470 nm. Thus, the decrease in peak intensity of phloxine-B after complex formation is used to quantitatively measure total glucosinolates in Arabidopsis thaliana seeds. For qualitative analysis, complex formation with eosin-B is used. The sensitivity of eosin-B detection at excitation/emission 470 nm/540 nm was low However, sensitivity increased following complex formation with sinigrin (>= 3 mu g/mL). A batch-learning, self-organizing map was applied to visualize and organize analytical data into 2-D matrix with similar and related data clustered together or near each other. This organized matrix was used to optimize electrophoretic conditions for the analysis. This study suggests potential applications of mu-CE in plant metabolomics analyses without use of labeling fluorophores.
  • Numerical analysis of thermal lens effect for sensitive detection on microchips
    Ryo Anraku, Kazuma Mawatari, Manabu Tokeshi, Masatoshi Nara, Takahiro Asai, Akihiko Hattori, Takehiko Kitamori
    Electrophoresis, 29, 9, 1895, 1901, WILEY-V C H VERLAG GMBH, 2008年05月, [査読有り]
    英語, 研究論文(学術雑誌), Thermal lens microscope (TLM) is a sensitive detection method for nonfluorescent molecules and widely applied to detection in a capillary or on a microchip. In this paper, we developed a flexible design tool for TLM systems to meet various applications utilizing a microspace. The TL effect was modeled, including signal processing, and calculated by combining fluidic dynamics and wave optics software. The coincidence of the calculations and experiments was investigated by measuring the effects of optical path length or focus positions of the excitation beams on TL signals which are quite difficult to calculate by a conventional method. Good agreement was shown and the applicability of the TLM design tool was verified.
  • Accurate quantitation of salivary and pancreatic amylase activities in human plasma by microchip electrophoretic separation of the substrates and hydrolysates coupled with immunoinhibition
    Eiki Maeda, Masatoshi Kataoka, Shouki Yatsushiro, Kazuaki Kajimoto, Mami Hino, Noritada Kaji, Manabu Tokeshi, Mika Bando, Jun-Ichi Kido, Mitsuru Ishilkawa, Yasuo Shinohara, Yoshinobu Baba
    Electrophoresis, 29, 9, 1902, 1909, WILEY-BLACKWELL, 2008年05月
    英語, 研究論文(学術雑誌), A high-performance determination system for alpha-amylase isoenzyme activities in human plasma involving microchip electrophoresis with a plastic chip was developed. The combination of microchip electrophoresis for substrate and hydrolysate separation and an immunoinhibition method for the differentiation of isoenzyme activities using antihuman salivary amylase (S-AMY) mAb allowed the highly selective determination of amylase isoenzyme (S-AMY and pancreatic amylase (P-AMY)) activities even in a complex matrix such as a crude plasma sample. We used 8-aminopyrene-1,3,6-trisulfonic acid (APTS)-labeled maltohexaose (G6) as a substrate. Amylase in a human plasma sample hydrolyzed APTS-G6 into APTS-maltotriose (G3) and G3, which was measured as the fluorescence intensity of APTS-G3 on microchip electrophoresis. A double logarithm plot revealed a linear relationship between amylase activity and fluorescence intensity in the range of 5-500 U/L of and the LOD was 4.38 U/L. Amylase activities in 13 amylase activity (r(2) = 0.9995 p < 0.01), subjects determined by the present method were compared with the results obtained by conventional methods with nitrophenylated oligosaccharides as substrates, respectively. Good correlations were observed for each method on simple linear regression analysis (both p < 0.01). The reproducibilities of within-days for total amylase and P-AMY were 2.98-6.27 and 3.83-6.39%, respectively, and these between-days were 2.88-5.66 and 3.64-5.63%, respectively. This system enables us to determine amylase isoenzyme activities in human plasma with high sensitivity and accuracy, and thus will be applicable to clinical diagnosis.
  • Rinse and evaporation coating of poly(methyl methacrylate) microchip for separation of sodium dodecyl sulfate-protein complex
    Hiroki Okada, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Journal of Chromatography A, 1192, 2, 289, 293, ELSEVIER SCIENCE BV, 2008年05月
    英語, 研究論文(学術雑誌), We developed a novel channel wall coating on a poly(methyl methacrylate) (PMMA) microchip using methylcellulose (MC) as a coating reagent to suppress electroosmotic flow (EOF) following the strong analytes adsorption via hydrophobic interaction with channel walls of PMMA. Our coating was obtained by first rinsing channel walls with MC-containing aqueous solution followed by evaporation. The coating made the hydrophilic channel wall lowering EOF by two orders of magnitude (1.2 x 10(-5) cm(2) V-1 s(-1)) as well as reducing the hydrophobic adsorption. On the coated channel walls, we successfully separated sodium dodecyl sulfate-protein complexes with high reproducibility and efficiency using dextran as a lower viscosity protein separation medium. (c) 2008 Elsevier B.V. All rights reserved.
  • Rolling circle amplification and circle-to-circle amplification of a specific gene integrated with electrophoretic analysis on a single chip
    Laili Mahmoudian, Noritada Kaji, Manabu Tokeshi, Mats Nilsson, Yoshinobu Baba
    Analytical Chemistry, 80, 7, 2483, 2490, AMER CHEMICAL SOC, 2008年04月
    英語, 研究論文(学術雑誌), We have developed an integrated platform for rolling circle amplification (RCA) and circle-to-circle amplification (C2CA) of circular probe (padlock probe) and subsequent microchip electrophoretic detection of a specific gene on a poly(methyl methacrylate) microchip. RCA and C2CA were successfully carried out at a steady temperature of 37 degrees C in the sample well of the microchip, and their respective product was detected on the same channel of the microchip, which was prefilled with a polymer separation matrix and fluorescent dye. Using a species-specific padlock probe for bacterial pathogen V. cholerae, a 25-ng bacterial genomic DNA could be detected in less than 65 min (including RCA and microchip electrophoresis) by this platform. Stable dsDNA C2CA product of genomic DNA for V. cholerae can be detected with the introduced integrated platform. Furthermore, the usefulness of this technique for the monitoring of RCA was demonstrated. This integrated platform provides a sensitive, fast, high-throughput, and reproducible method for signal amplification and detection of the padlock probes in the same microchip and is a promising tool for highly specific gene detection strategies.
  • Microchip electrophoresis for specific gene detection of the pathogenic bacteria V-cholerae by circle-to-circle amplification
    Laili Mahmoudian, Jonas Melin, Mohamad Reza Mohamadi, Keiko Yamada, Michio Ohta, Noritada Kaji, Manabu Tokeshi, Mats Nilsson, Yoshinobu Baba
    Analytical Sciences, 24, 3, 327, 332, JAPAN SOC ANALYTICAL CHEMISTRY, 2008年03月
    英語, 研究論文(学術雑誌), We have developed a new method for a fast and precise analysis of circle-to-circle amplification (C2CA) product for specific gene detection by microchip electrophoresis. In this method, we have added a new enzymatic step to the C2CA reaction, which could be carried out isothermally at 37 degrees C. Compared to the original single-stranded DNA, the double-stranded DNA that is produced by this enzymatic reaction is more reliable for analysis by microchip electrophoresis. C2CA product was detected within 55 s with high reproducibility by this method which was successfully applied to the detection of 10-ng genomic DNA of the pathogenic bacteria Vibrio. cholerae within I 10 s. Purification was found to be an indispensable step for the analysis of the C2CA product of genomic DNA samples.
  • Poly(methylmethacrylate) microchip electrophoresis of proteins using linear-poly(acrylamide) solutions as separation matrix
    Hiroki Okada, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Analytical Sciences, 24, 3, 321, 325, JAPAN SOC ANALYTICAL CHEMISTRY, 2008年03月
    英語, 研究論文(学術雑誌), Poly(methylmethacrylate) (PMMA) microchip electrophoresis of sodium dodecyl sulfate-protein complexes (SDS-PC) using linear-poly(acrylamide) (L-PA) as a separation matrix was investigated. Prior to electrophoresis, channel walls of PMMA were modified with methylcellulose (MC) to prevent adsorption between channel walls and SDS-PC. Size-based protein separation (SBPS) was successfully performed using the MC-coated microchips with Ferguson plot-fittings. The entangled L-PA solution provided high resolution of peaks of SDS-PC when the concentration of L-PA was increased. Some investigations into the separation mechanism, such as the plot of the logarithm of mobility of each SDS-PC versus the logarithm of the molecular weight of the complex exhibiting linear behavior, indicated that the separation mechanism was dependent on mass discrimination, in accordance with Ogston model.
  • Quantitative determination of amino acids in functional foods by microchip electrophoresis
    Hiroko Ueno, Jun Wang, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Journal of Separation Science, 31, 5, 898, 903, WILEY-V C H VERLAG GMBH, 2008年03月
    英語, 研究論文(学術雑誌), Microchip electrophoresis (MCE), a first-generation micrototal analysis system, has emerged during the miniaturization phase of food analysis. Based on the micellar electrokinetic chromatography mode, a simple and fast MCE method with light emitting diode-induced fluorescence detection was developed for quantitative analysis of amino acids in three different kinds of functional foods, viz. sports beverages, jelly-form beverages, and tablet-form functional foods. In contrast to the glass microchip, we improved the separation of amino acids on a poly(methyl methacrylate) (PMMA) chip by addition of cationic starch derivatives. 4-Fluoro-7-nitro-2,1,3-benzoxacliazole, which has a short labeling time for amino acids, was used as the fluorescently labeled dye. This NICE method takes less than 10 min of total analysis time including sample preparation and analysis of amino acids in functional foods on a PMMA chip. The results show that this approach has the potential to be a fast and simple method for amino acid analysis in functional foods.
  • Nuclease tolerant FRET probe based on DNA-quantum dot conjugation
    Daisuke Onoshima, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Analytical Sciences, 24, 2, 181, 183, JAPAN SOC ANALYTICAL CHEMISTRY, 2008年02月
    英語, 研究論文(学術雑誌), We,have developed a fluorescence resonance energy transfer (FRET) probe based on the conjugation of a quantum dot (QD) with dye (YOYO-3) intercalated DNA. The FRET-inducing electrostatic coupling of DNA and the QD made structural changes to the QD-DNA conjugates, which significantly prevented an enzymatic reaction between the DNA and a conventional restriction endonuclease (EcoRI).
  • Modification of the microchannel in polymer microchips
    Yukihiro Okamoto, Yeon Su Park, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference, 892, 894, 2008年, [査読有り]
    研究論文(国際会議プロシーディングス), We have developed an easy and versatile method for the surface modification of the microchannels in polymer microchips. Our method employed N-5-azido-2- nitrobenzoyloxysuccinimide, a photo-reactive azide, for the surface modification. Unlike the previously developed methods, it allows us to immobilize biomolecules without sacrificing their activity as well as to coat polymers which inhibit protein adsorption. Moreover, it does not require specific equipment, highly toxic chemicals, or labor-intensive procedures. © 2008 CBMS.
  • Robust surface modification for protein separation chip using a film of a cellulose derivative
    H. Okada, N. Kaji, M. Tokeshi, Y. Baba
    12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference, 251, 253, 2008年, [査読有り]
    研究論文(国際会議プロシーディングス), We developed a new surface modification method using poly(methyl methacrylate) (PMMA) with a film of a cellulose derivative to ensure the long-term stability of the modification. For electrophoretic protein separation using PMMA chips as well as other polymeric chips, protein adsorption is so inevitable that analytical errors (band broadening, low detection sensitivity) are unavoidable. However, our new method overcame these drawbacks of polymeric materials and provided much better analytical performances (higher theoretical plates and consecutive runs in a single channel) than other reported methods of surface modification. © 2008 CBMS.
  • Dynamic cross-linking effect of Mg2+ to enhance sieving properties of low-viscosity poly(vinylpyrrolidone) solutions for microchip electrophoresis of proteins
    Mohamad Reza Mohamadi, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Analytical Chemistry, 80, 1, 312, 316, AMER CHEMICAL SOC, 2008年01月
    英語, 研究論文(学術雑誌), We report a dynamic cross-linking effect of Mg2+ that enhances the sieving properties of low-viscosity poly(vinylpyrrolidone) (PVP) solutions. A low-viscosity PVP solution was applied to nondenaturing microchip electrophoresis of protein samples using microchips made of poly(methyl methacrylate). The separation resolution of nondenatured protein markers in 1.8% PVP solution was improved by adding 1-20 MM MgCl2. We studied the effect of the ratio of cross-linking agent on mobility of protein samples and showed that protein retardation (In mu/mu(0)) is correlated with the ratio of cross-linking agent to PVP ([c(Mg)(2+)/c(PVP)]) as In mu/mu(0) = A'[c(Mg)(2+)/c(PVP)](b'). A' was related to the protein radius (R), and b' was found to be 0.72 for proteins with R = 2.4 nm and 0.82 for proteins with R = 1.85 nm. A structural study of PVP in semidilute solutions using dynamic light scattering showed that incremental increases of Mg2+ ion concentration from 5 to 20 mM in 1.8% PVP solution increased the hydrodynamic radius of PVP polymers by 20%.
  • Channel wall coating on a poly-(methyl methacrylate) CE microchip by thermal immobilization of a cellulose derivative for size-based protein separation.
    Hiroki Okada, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Electrophoresis, 28, 24, 4582, 9, 2007年12月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), We demonstrate channel wall coating using a cellulose derivative on a poly-(methyl methacrylate) (PMMA) CE microchip to eliminate EOF disturbing protein separation. The channel walls were modified by preconditioning with a solution containing the cellulose derivative and then thermally evaporating the solution to produce hydrophilic channel walls which prevent adsorption of analytes via a hydrophobic interaction. When the PMMA substrate was coated with the cellulose derivative hydroxypropylmethylcellulose (HPMC) 90SH, the water contact angle on the coated substrate was decreased (up to 15 degrees ) and EOF was significantly suppressed (up to 4.0 x 10(-6) cm2.V(-1)s(-1)). Three proteins (20.5, 68.0, and 114.6 kDa) were successfully separated on the 0.15% HPMC 90SH-coated channel walls with good reproducibility of migration time (RSD <1.75%) and high efficiency (theoretical plate number per meter: 2.62 x 10(5)).
  • Dynamic modification of poly(methyl methacrylate) chips using poly(vinyl alcohol) for glycosaminoglycan disaccharide isomer separation.
    Yong Zhang, Guichen Ping, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Electrophoresis, 28, 18, 3308, 14, 2007年09月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), We describe a microchip electrophoresis (MCE) method for the assay of unsaturated disaccharides of chondroitin sulfates, dermatan sulfates, and hyaluronic acid (HA). Poly(vinyl alcohol) (PVA) could be irreversibly adsorbed onto poly(methyl methacrylate) (PMMA) substrates and this approach was applicable for dynamic coating. The characteristics of the PMMA surface with PVA coating were evaluated in terms of the wettability, EOF, and adsorption of 2-aminoacridone (AMAC)-labeled disaccharide. The water contact angle decreased from 73 degrees on a pristine PMMA surface to 37.5 degrees on a PVA-coated surface, indicating that the PVA coating increased hydrophilicity. EOF was reduced approximately twofold and was relatively stable. Scanning electron microscopy and fluorescence microscopy images showed that adsorption of AMAC-labeled disaccharides was dramatically suppressed. Using the PVA coating, baseline separation of two pairs of glycosaminoglycan (GAG) disaccharide isomers, DeltaDi-diS(B)/DeltaDi-diS(D) and DeltaDi-0S/DeltaDi-HA, was achieved in Tris-borate buffer within 130 s by MCE.
  • Nanobiotechnology: quantum dots in bioimaging.
    Yong Zhang, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Expert Review of Proteomics, 4, 4, 565, 72, 2007年08月, [査読有り], [国際誌]
    英語, Many biological systems, including protein complexes, are natural nanostructures. To better understand these structures and to monitor them in real time, it is becoming increasingly important to develop nanometer-scale signaling markers. Single-molecule methods will play a major role in elucidating the role of all proteins and their mutual interactions in a given organism. Fluorescent semiconductor nanocrystals, known as quantum dots, have several advantages of optical and chemical features over the traditional fluorescent labels. These features make them desirable for long-term stability and simultaneous detection of multiple signals. Here, we review current approaches to developing a biological application for quantum dots.
  • Online preconcentration by transient isotachophoresis in linear polymer on a poly(methyl methacrylate) microchip for separation of human serum albumin immunoassay mixtures.
    Mohamad Reza Mohamadi, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Analytical Chemistry, 79, 10, 3667, 72, 2007年05月15日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Online preconcentration of human serum albumin (HSA) and its immunocomplex with a monoclonal antibody by on-chip transient isotachophoresis is reported. An 800-fold signal enhancement was achieved following the preconcentration on standard cross-channel microchips made of poly (methyl methacrylate). Sample injection, preconcentration, and separation were done continuously and controlled solely by a sequential voltage switching program. The preconcentration was followed by on-chip nondenaturing gel electrophoresis in methylcellulose solution. The method was applied to microchip electrophoresis immunoassay of HSA. Baseline separation of HSA and its immunocomplex was achieved in 25 s in the first 1 cm of the microchannel. In a direct immunoassay, the minimum detectable concentration of fluorescent labeled HSA by laser-induced fluorescence detection was 7.5 pM.
  • Evaluation of amplified cRNA targets for oligonucleotide microarrays.
    Akihiro Sawada, Shogo Mizufune, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Analytical and Bioanalytical Chemistry, 387, 8, 2645, 54, 2007年04月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Due to their hybridization specificity and capacity for systematic gene discovery, oligonucleotide-based microarray platforms offer numerous advantages over the cDNA microarrays currently widely used for comprehensive analysis of gene expression. Although fluorescently labeled amplified cRNA generated by T7 transcription is generally used in oligonucleotide microarrays, the feasibility of this combination (and that of cDNA microarrays) is yet to be studied systematically. In this paper, we performed a comparative study using a direct labeling method and T7 amplification to evaluate amplified cRNA targets for oligonucleotide microarrays. The efficiency of incorporation of Cy3- and Cy5-CTP into the target preparations, the reproducibility and the number of genes detected were investigated for each labeling approach and compared. The 12 genes that showed different expression profiles in the two labeling methods were evaluated by quantitative real-time PCR. In the 60-mer oligonucleotide microarray, amplified cRNA targets prepared by the T7 amplification method showed higher reproducibility and reliability than targets prepared by the direct labeling method in a comparative analysis of gene expression. This result also suggests the importance of fragmenting cRNA down to lengths of 50-200 bases before the hybridization process.
  • Enhanced electrophoretic resolution of monosulfate glycosaminoglycan disaccharide isomers on poly(methyl methacrylate) chips.
    Yong Zhang, Guichen Ping, Bingmei Zhu, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Electrophoresis, 28, 3, 414, 21, 2007年02月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), To improve the separation of monosulfate glycosaminoglycan disaccharide isomers by microchip electrophoresis, we found that addition of 1,4-dioxane (DO) dramatically improved analyte resolution, probably due to solvation effects. Methylcellulose (MC) was tested for the ability to suppress EOF and analyte adsorption to the chip. To improve analyte resolution, buffer pH, beta-CD, and DO were systematically investigated. Fast separation was achieved by increasing the electric field strength, and field-amplified sample stacking occurred with increasing buffer concentrations. Therefore, based on our findings, we describe an efficient method for the separation of monosulfate and trisulfate unsaturated disaccharides (DeltaDi-UA2S, DeltaDi-4S, DeltaDi-6S, and DeltaDi-triS) derivatized with 2-aminoacridone hydrochloride. A mixture of monosulfate disaccharide isomers (DeltaDi-UA2S, DeltaDi-4S, and DeltaDi-6S) was baseline-separated within 75 s on a poly(methyl methacrylate) chip using a mixed buffer (DO/running buffer 57:43 v:v), 0.5% MC, pH 6.81, with an E(sep) of 558 V/cm. The theoretical plate was in the range of 5 x 10(5) to 1 x 10(6) m-1.
  • Temperature dependent phase behavior of n-cyclohexyl-2-pyrrolidone/water system in a microchannel and phase separation using viscosity difference               
    Yoshikuni Kikutani, Hidematsu Ikeda, Masayuki Harada, Yasuhisa Ikeda, Manabu Tokeshi, Takehiko Kitamori
    Proceedings of the 11th International Conference on Miniaturized Systems for Chemistry and Life Sciences, uTAS 2007, 955, 957, Chemical and Biological Microsystems Society, 2007年
    英語, 研究論文(国際会議プロシーディングス), Aqueous solution of N-cyclohexyl-2-pyrrolidone (NCP), which is known as a selective precipitant for U(VI), changes into two solution phases (NCP-rich and -poor phases) upon heating. Aiming at development of a new actinoid separation method utilizing NCP solutions, we investigated characteristics of NCP solutions. We found that novel phase separation method using microfluidics could be applied to NCP/water system.
  • Solvent extraction on chips               
    Manabu Tokeshi, Takehiko Kitamori
    Handbook of Capillary and Microchip Electrophoresis and Associated Microtechniques, Third Edition, 1021, 1036, CRC Press, 2007年01月01日
    英語, 論文集(書籍)内論文, Solvent extraction is a method capable of separating compounds based on their solution preferences for two different immiscible liquids. In other words, it is the extraction of a substance from one liquid phase into another liquid phase. Solvent extraction is a fundamental technique in chemical/biological laboratories and chemical industries, where it is carried out in the macroscale using separatory funnels. The advantage of doing a solvent extraction in the microspace on a chip is the scale merit of using small dimensions, that is, a large specific interface area (the interface-to-volume ratio) and a short diffusion distance, which together results in a short diffusion time. High speed and high performance solvent extraction systems are possible on chips, without the need for mechanical stirring, mixing, or shaking, all of which are necessary for the conventional method.
  • Determination of total and pancreatic amylase activities in human blood by use of microchip electrophoresis
    Eiki Maeda, Masatoshi Kataoka, Yasuo Shinohara, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Proceedings of the 11th International Conference on Miniaturized Systems for Chemistry and Life Sciences, uTAS 2007, 65, 67, 2007年
    研究論文(国際会議プロシーディングス), In this study, a high-performance determination system for isoenzyme activities of human a-amylase was developed using microchip electrophoresis (ME) with a plastic chip. The combination of ME for substrate/hydrolysate separation and immunomhibition method for differentiation of isoenzymes using anti human salivary amylase (S-AMY) monoclonal antibody, Tu88E8, realized the highly selective determination of amylase isoenzyme activities even in a complex matrix such as a blood sample. This paper demonstrates that this system enables us to determine amylase isoenzyme activities with easy operation and high accuracy, and it will be applicable to clinical diagnosis for acute pancreatic disorders.
  • A more excellent construction method of a multi functional envelope-type nano device on microdevice for gene therapy
    Hiroshi Kuramoto, Noritada Kaji, Kentarou Kogure, Manabu Tokeshi, Yasuo Shinohara, Hideyoshi Harashima, Yoshinobu Baba
    Proceedings of the 11th International Conference on Miniaturized Systems for Chemistry and Life Sciences, uTAS 2007, 781, 783, 2007年
    研究論文(国際会議プロシーディングス), A multifunctional envelope-type nano device (MEND) is an extremely efficient technology for a non-viral gene delivery system. However, the construction processes of the MEND by the existing method are very complicated. Therefore we develop a new method to construct it quickly and easily in the previous work. In this work, we report a new on-chip construction method of the MEND which is much more suitable for the gene therapy.
  • Single DNA/protein interaction analysis using quantum dot conjugates and microfluidic systems
    D. Onoshima, N. Kaji, M. Tokeshi, Y. Baba
    Proceedings of the 11th International Conference on Miniaturized Systems for Chemistry and Life Sciences, uTAS 2007, 1619, 1621, 2007年
    研究論文(国際会議プロシーディングス), We have designed a microfluidic detection platform in which we can monitor and analyze single DNA/protein dynamic interaction using “single-molecule fluorescence tracing”. The use of quantum dot (QD) labelling on DNA, polydimethylsiloxane (PDMS) microchip, micro patterning of active enzymes, and total internal reflection fluorescence (TIRF) microscope was successfully applied for nano-space experiments in micrometer-sized channels. We used this detection platform to observe the enzymatic reaction of restriction endonuclease (EcoRI) and measured the duration of its cleavage reaction.
  • Simulation Examination for Multilayer Flow System
    Ryo Anraku, Takahiro Asai, Kenji Uchiyama, Akihiko Hattori, Manabu Tokeshi, Takehiko Kitamori
    WORLD CONGRESS ON MEDICAL PHYSICS AND BIOMEDICAL ENGINEERING 2006, VOL 14, PTS 1-6, 14, 318, +, SPRINGER-VERLAG BERLIN, 2007年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), In this study, we compared the observation experiment of a liquid-liquid interface with a simulation result about the three-phase micro channel used for an extraction reaction. As a result, each flow rate ratio greatly influences the formation of the three-phase flow. And the result of computing this multiphase flow model is corresponding to the experiment well, so the development of the unit chemistry operation model will become possible with the simulation in the future.
  • Highly sensitive detection of non-labeled peptides using UV excitation thermal lens microscope/liquid chromatography
    Shinichiro Hiki, Manabu Tokeshi, Masaya Kakuta, Kazuma Mawatari, Yoshikuni Kikutani, Kiichi Sato, Akihide Hibara, Kiyohito Shimura, Naoyuki Uchida, Takehiko Kitamori
    Bunseki Kagaku, 56, 1, 1, 7, 2007年, [査読有り]
    日本語, 研究論文(学術雑誌), A UV excitation thermal-lens microscope (UV-TLM) with an excitation beam wavelength of 266 nm and liquid chromatograph (LC) were connected to build a new system (LC/UV-TLM) for the separation and highly sensitive label-free determination of biomolecules, such as peptides. A variation in the composition of the mobile phase with time, as in gradient elution, is very commonly utilized in LC for improved separations. Thermal-lens signals are generally highly dependent on the properties of the media surrounding the photo-absorber. This effect must be carefully considered in such situations where the composition of a solution drastically changes in time. Therefore, we tested the developed LC/UV-TLM system operated in a gradient elution mode, by observing the effects of the variation in the solution composition upon TLM signal intensities. In water/acetonitrile gradient elution, no serious effects were observed as long as the acetonitrile content was less than 40% v/v. We then tested the developed system in the separation of a standard sample solution of mixed synthetic peptides
    we found that the developed system was 10-times more sensitive than a conventional system with the spectrophotometer used as a detector. © 2007 The Japan Society for Analytical Chemistry.
  • Nanoscale DNA analysis
    Laili Mahmoudian, Mohamad Reza Mohamadi, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Handbook of Capillary and Microchip Electrophoresis and Associated Microtechniques, Third Edition, 1527, 1542, 2007年01月01日, [査読有り]
    論文集(書籍)内論文, © 2008 by Taylor & Francis Group, LLC. Microchip electrophoresis has been developed as a promising technology for detection of DNA in samples.1-3 However, the development of systems for the separation of long DNA strands [greater than several kilo basepairs (kbps)] using commercially available media, has not been successful.4 In recent years, efforts have been focused on the overcoming the limitations of current DNA electrophoresis methods. Those limitations largely result from an application base that only required the separation of DNA fragments in a narrow size range, one where using fundamental separation modes based on sieving using conventional methods.5 In conventional gel electrophoresis, DNA molecules move in the electric field based on a size-dependent mobility through pores in a gel matrix.6 However, length-dependent mobility vanishes for DNA molecules longer than 40 kbps, primarily due to tendency of DNA molecules to become stretched and oriented to the direction of electric field.7,8 Buoyed by the knowledge of micro- and nanofabrication technologies, nanotechnology has been shown to be quite successful for long fragment DNA analysis. To achieve the required efficiency needed for this type of DNA electrophoresis, two directions in the field of nanotechnology have been established: one focused on providing artificial gel structures produced with nanofabrication technology, and the other on nanomaterials for DNA separation. In this chapter, we discuss the developments and capabilities of nanoscale methods for DNA electrophoresis, and provide some important technical information for each method. Considering the point that the mechanism of DNA separation in each nanotechnique is different (and sometimes unique) from other better-understood separation modes, these will be explained separately.
  • Single-molecule measurements with a single quantum dot.
    Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Chemical Record (New York, N.Y.), 7, 5, 295, 304, 2007年, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Recent progress of quantum dot (QD) applications in single-molecule measurements are reviewed in this paper. Bright fluorescence and anti-photobleaching properties of QDs have explored the way to conduct long-time trajectory tracking of transmembrane proteins both in vitro and in vivo. Coupled with diversities of chemical and biochemical modifications of QD surfaces, their application fields are expanding to multidiscipline fields including imaging on the basis of a single molecule. Currently, molecular interactions and conformational changes on the QD surface can be detected at a single-molecule level. These expansions of application fields also involve toxicity problems in cells since most commercially available QDs consist of cadmium selenide or cadmium telluride, which are inherently toxic. For widespread applications of QDs including in vivo and therapeutic use in place of current organic fluorophore, cytotoxicity is discussed as well in this paper. 10.1002/tcr.20128.
  • Quantum dots for single bio-molecule imaging.
    Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Analytical Sciences, 23, 1, 21, 4, 2007年01月, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌), The emerging nanomaterial, quantum dots or QDs, offers numerous potential applications in the biological area. As cell labeling probes, QDs become now an alternative of existing organic fluorescent dyes and fluorescent proteins. In this short review, we cover typical and successful applications of QDs as fluorescent probes in cell labeling and genomic diagnosis. As a future important application, biomolecular detection at a single molecule level utilizing QDs is also discussed.
  • Development of the microchip-based repeatable immunoassay system for clinical diagnosis
    M. Kakuta, H. Takahashi, S. Kazuno, K. Murayama, T. Ueno, M. Tokeshi
    Measurement Science and Technology, 17, 12, 3189, 3194, Institute of Physics Publishing, 2006年12月01日, [査読有り]
    英語, 研究論文(学術雑誌), A microchip-based semi-automated heterogeneous immunoassay was developed wherein a flow injection-like system and repeatable-use gel were employed. Microfluidics used a pump with highly accurate control of flow rate, two injector valves and a microchip. The results of a system suitability test based on dye injection for microfluidics including a thermal lens microscope as a detector were good. A regeneration buffer for antigen-antibody interaction of brain natriuretic peptide (BNP) was found which did not lose binding activity of the antibody on the gels and integration of such an immunoassay scheme into a semi-automated microfluidics system would facilitate repeated-use heterogeneous immunoassay. Good reproducibility of BNP assay was obtained with the selected regeneration buffer. The concentration of BNP in the range of 0.1-100 pg mL -1 (n ≤ 3) was successfully determined using the system and protocol developed here. © 2006 IOP Publishing Ltd.
  • Pressure-driven flow control system for nanofluidic chemical process
    Eiichiro Tamaki, Akihide Hibara, Haeng-Boo Kim, Manabu Tokeshi, Takehiko Kitamori
    JOURNAL OF CHROMATOGRAPHY A, 1137, 2, 256, 262, ELSEVIER SCIENCE BV, 2006年12月, [査読有り]
    英語, 研究論文(学術雑誌), We developed a novel flow control system for a nanofluidic chemical process. Generally, flow control in nanochannels is difficult because of its high-pressure loss with very small volume flow rate. In our flow control method, liquid pressure in a microchannel connected to the nanochannels is regulated by utilizing a backpressure regulator. The flow control method was verified by using simple structured microchip, which included parallel nanochannels. We found that the observed flow rate was three times lower than the value expected from Hagen-Poiseuille's equation. That implied a size-dependent viscosity change in the nanochannels. Then, we demonstrated mixing of two different fluorescent solutions in a Y-shaped nanochannel and also a proton exchange reaction in the Y-shaped nanochannel. The flow control method will contribute to further integration of nanochemical systems. (c) 2006 Elsevier B.V. All rights reserved.
  • Study of water properties in nanospace.
    Noritada Kaji, Ryo Ogawa, Akio Oki, Yasuhiro Horiike, Manabu Tokeshi, Yoshinobu Baba
    Analytical and Bioanalytical Chemistry, 386, 3, 759, 64, 2006年10月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Here we report an anomalous behavior of water, especially its viscosity and hydrodynamic flow, in a nanometer-confined space. As a typical model of a nanometer-confined space, the nanopillar chip, which was developed for DNA size-based separation was used, and single-particle tracking (SPT) technique was applied to investigate water viscosity and hydrodynamic flow in the nanopillar chip. The diffusion coefficients of nanospheres were almost one-third of the theoretical value derived from the Stokes-Einstein equation. This result gave indirect proof that water viscosity in a nanometer-confined space is higher than in a bulk solution. In order to improve resolution and throughput of the nanopillar chip for DNA separation, these potential factors affecting performance should be seriously considered.
  • Microchip-based liquid-liquid extraction for gas-chromatography analysis of amphetamine-type stimulants in urine
    Hajime Miyaguchi, Manabu Tokeshi, Yoshikuni Kikutani, Akihide Hibara, Hiroyuki Inoue, Takehiko Kitamori
    JOURNAL OF CHROMATOGRAPHY A, 1129, 1, 105, 110, ELSEVIER SCIENCE BV, 2006年09月, [査読有り]
    英語, 研究論文(学術雑誌), A microchip-based liquid-liquid extraction for the gas chromatography analysis of urine for amphetamine-type stimulants has been developed. Partially modified microchannels with the capillarity restricted modification (CARM) method were employed for stabilizing the interface consisting of 1-chlorobutane and alkalized urine. Reliability of the microchip-based extraction was evaluated with respect to linearity, trueness and precision. As a practical demonstration, methoxyphenamine hydrochloride (50 mg) was administered to three healthy volunteers, and the concentration of methoxyphenamine in their urine was determined by both methods for comparison. This study showed the potential of pressure-driven microfluidics to contribute to the rapid automation analysis in forensic toxicology. (c) 2006 Elsevier B.V. All rights reserved.
  • Rapid multiplexing and simultaneous detection of human spermatogenetic failure with a 12 lane microchip electrophoresis system.
    Mohammad Jabasini, Ashraf Abdulazim Ewis, Maged Fouad, Fuquan Dang, Guichen Ping, Toshikatsu Shinka, Yutaka Nakahori, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Biological & Pharmaceutical Bulletin, 29, 7, 1487, 9, 2006年07月, [査読有り], [国内誌]
    英語, For the amplification and ultrafast separation of the genetic markers and DNA sequences that are related to human male infertility, a multiplex PCR for amplifying three DNA sequence-tagged sites (STS) located on the human Y chromosome with possible roles in the spermatogenesis process has been designed and applied followed by separation on a microchip. First, the optimum T(m) degree for the three DNA markers was optimized and determined experimentally, and the three DNA STS were amplified. These three DNA markers were then separated on a 12-lane microchip electrophoresis system, which can analyze the DNA markers on 12 channels simultaneously. The combination of these two technologies, multiplex PCR and microchip electrophoresis, allows the analysis of 36 DNA markers (12x3) within only 180 s.
  • Electrophoretic behavior of plasmid DNA in the presence of various intercalating dyes.
    Fuquan Dang, Wenhao Li, Lihua Zhang, Mohammad Jabasini, Tatsuhiro Ishida, Hiroshi Kiwada, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Journal of Chromatography. A, 1118, 2, 218, 25, 2006年06月23日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), In the present study, the electrophoretic behavior of linear, supercoiled and nicked circular plasmid DNA in the presence of various intercalating dyes was characterized using pGL3 plasmid DNA as a model. The enzymatic digestion of pGL3 plasmid DNA with HindIIIwas monitored by capillary electrophoresis coupled with laser-induced fluorescence detection (CE-LIF). Nicked circular plasmid DNA was found to be relatively sensitive to enzymes, and was almost digested into the linear conformer after 10-min incubation, indicating that nicked circular plasmid DNA has little chance of targeting and entering the cell nucleus. Partly digested plasmid DNA containing only linear and supercoiled conformers can be used as a standard to confirm the migration order of plasmid DNA. In methylcellulose (MC) solution with YO-PRO-1 or YOYO-1, linear plasmid DNA eluted first, followed by supercoiled and nicked plasmid DNA, and nicked plasmid DNA eluted as a broad peak. With SYBR Green 1, nicked plasmid DNA eluted first as three sharp peaks, followed by linear and supercoiled plasmid DNA. The nuclear plasmid DNA from two transfected cell lines was successfully analyzed using the present procedure. Similar results were obtained with an analysis time of seconds using microchip electrophoresis with laser-induced fluorescence detection (mu-CE-LIF). To our knowledge, these results represent the first reported analysis of nuclear plasmid DNA from transfection cells by CE-LIF or mu-CE-LIF without pre-preparation, suggesting that the present procedure is a promising alternative method for evaluating transfection efficiency of DNA delivery systems.
  • Quantitative detection and fixation of single and multiple gold nanoparticles on a microfluidic chip by thermal lens microscope
    Kazuma Mawatari, Manabu Tokeshi, Takehiko Kitamori
    Analytical Sciences, 22, 5, 781, 784, 2006年05月, [査読有り]
    英語, 研究論文(学術雑誌), A detection and fixation method of single and multiple gold nanoparticles on the wall of a microfluidic channel is demonstrated. A thermal lens microscope (TLM) with continuous-wave excitation (wavelength, 532 nm) and probe (wavelength, 670 nm) laser beams was used to realize the sensitive detection of heat generated by light absorption of individual gold nanoparticles (50 nm in diameter)
    fixation of the individual nanoparticles was realized simultaneously. The fixation mechanism was investigated and attributed to an absorption-based optical force. In addition to single nanoparticle detection, multiple-nanoparticle detection and fixation was demonstrated. An acceleration of fixation was observed when the number of fixed particles was increased. TLM is expected to be a powerful tool for both the quantitative detection and precise fixation of individual nanoparticles. 2006 © The Japan Society for Analytical Chemistry.
  • Circular dichroism thermal lens microscope for sensitive chiral analysis on microchip
    Masayo Yamauchi, Kazuma Mawatari, Akihide Hibara, Manabu Tokeshi, Takehiko Kitamori
    Analytical Chemistry, 78, 8, 2646, 2650, 2006年04月15日, [査読有り]
    英語, 研究論文(学術雑誌), A novel chiral detector, a circular-dichroism thermal lens microscope (CD-TLM), was developed to realize sensitive and selective detection of small volume chiral samples on a microchip. To realize chiral recognition on TLM, an excitation beam was phase-modulated at a frequency of 1.2 kHz, and left-circularly polarized light (LCPL) and right-circularly polarized light (RCPL) were generated. Then, the differential light absorption between LCPL and RCPL, which is the CD effect, was detected as thermal lens signal intensity and phase. As a standard sample, optically active tris(ethylenediamine)cobalt(III) [Co-(en) 3] 3+I 3 - aqueous solutions were used for performance evaluations. First, we verified the basic principle for selective chiral analysis by comparing the signals in intensity-modulation and phase-modulation modes of the excitation beam. Also, we found that the g-factor, which is significant for determining enantiomeric excess, agreed well with the value obtained by the CD spectrometer. The limit of detection (LOD) for enantiopure [Co-(en) 3] 3+I 3 - was 6.3 × 10 -5 M (1.9 × 10 -7 abs) for (-)-Co(en) 3 3+, and the sensitivity in absorbance units was more than 250 times higher than that in a CD spectrophotometer. Finally, we demonstrated enantiomeric excess determination on a microchip. The LOD was 1.7% (8.5 × 10 -7 abs) for (-)-Co(en) 3 3+ and at least one order superior to the LOD of a CD spectrometer. The applicability of CD-TLM for sensitive chiral analysis on a microchip was verified, and CD-TLM is expected to be promising for microchip-based chiral synthesis and analysis systems. © 2006 American Chemical Society.
  • Monitoring of intercellular messengers released from neuron networks cultured in a microchip
    Kiichi Sato, Akiko Egami, Tamao Odake, Manabu Tokeshi, Makoto Aihara, Takehiko Kitamori
    Journal of Chromatography A, 1111, 2, 228, 232, 2006年04月14日, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), A cellular biochemistry analysis system was integrated on a quartz glass microchip with a microchamber for cell culture followed by a microchannel for detecting with a thermal lens microscope (TLM). Nerve cells from rat hippocampus were successfully cultured to form neural networks in the microchip. An aqueous solution of glutamate, which is known as a neurotransmitter, was introduced to stimulate the cultured neuron to release a retrograde messenger, arachidonate which is considered to be critical for neuronal plasticity, especially for long-term potentiation (LTP). After the introduction, the solution that flowed through the culture chamber was analyzed using the UV-TLM (excitation wavelength, 244 nm). The measured signal intensity was dependent on glutamate solution concentration, and the neurons were considered to release the retrograde messenger according to the glutamate concentration. This system is suitable for time-course monitoring of ultra trace amounts of chemicals released from very small amount of cultured cells. © 2005 Elsevier B.V. All rights reserved.
  • Liquid filling method for nanofluidic channels utilizing the high solubility of CO2
    E Tamaki, A Hibara, HB Kim, M Tokeshi, T Ooi, M Nakao, T Kitamori
    ANALYTICAL SCIENCES, 22, 4, 529, 532, JAPAN SOC ANALYTICAL CHEMISTRY, 2006年04月, [査読有り]
    英語, 研究論文(学術雑誌), We developed a fabrication method and a liquid filling method for a nano chemical reactor that used Y-shaped nanochannels specially designed for mixing and reacting. In order to reduce the pressure loss and to utilize the characteristics of the nanochannel, inlet microchannels were fabricated just beside the nanochannels. We investigated all initial liquid filling method into the nanochannels that ensured there were no air bubbles that could cause a flow stack due to the capillary pressure. In our method, the micro- and nanochannels were filled with carbon dioxide and any remaining air during the initial liquid introduction was dissolved utilizing the high solubility of carbon dioxide. We propose that chemical reactions in nanospaces can be realized by utilizing these fabrication and liquid introduction techniques.
  • Total reflection X-ray fluorescence analysis with chemical microchip
    Kouichi Tsuji, Yousuke Hanaoka, Akihide Hibara, Manabu Tokeshi, Takehiko Kitamori
    Spectrochimica Acta - Part B Atomic Spectroscopy, 61, 4, 389, 392, 2006年04月
    英語, 研究論文(学術雑誌), A chemical microchip, which has a flat region on the surface, was recently designed for total reflection X-ray fluorescence (TXRF) analysis. A sample solution was introduced from an inlet by a microsyringe and flowed into a microchannel. Finally it overflowed from the well-type microchannel on the flat region. The sample solution on this region was dried, and then measured by TXRF. The TXRF spectra could be measured with a low background level. This preliminary result indicated that the edge of the well-type channel would not cause a serious problem for TXRF analysis. In addition, a good linear relationship was obtained for Zn Kα in Zn standard solution. This suggests that quantitative analysis by TXRF is feasible in combination with a chemical microchip. © 2006.
  • Low viscous separation media for genomics and proteomics analysis on microchip electrophoresis system.
    Mohammad Jabasini, Yuji Murakami, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Biological & Pharmaceutical Bulletin, 29, 4, 595, 604, 2006年04月, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌), Microchip electrophoresis has widely grown during the past few years, and it has showed a significant result as a strong separation tool for genomic as well as proteomic researches. To enhance and expand the role of microchip electrophoresis, several studies have been proposed especially for the low viscous separation media, which is an important factor for the success of microchip with its narrow separation channels. In this paper we show an overview for the done researches in the field of low viscous media developed for the use in microchip electrophoresis. For genomic separation studies polyhydroxy additives have been used enhance the separation of DNA at low polymer concentration of HPMC (Hydroxypropylmethyl cellulose) which could keep the viscosity low. Mixtures of poly(ethylene oxide) as well as Hydroxyporpyl cellulose have been successfully introduced for chip separation. Furthermore high molecular mass polyacrylamides at low concentrations have been studied for DNA separation. A mixture of polymer nanoparticle with conventional polymers could show a better resolution for DNA at low concentration of the polymer. For the proteomic field isoelectric focusing on chip has been well overviewed since it is the most viscous separation media which is well used for the protein separation. The different types of isoelectric focusing such as the ampholyte-free type, the thermal type as well as the ampholyte-depended type have been introduced in this paper. Isoelectric focusing on chip with its combination with sodium dodecyl sulfate (SDS) page or free solution could give a better separation. Several application for this low viscous separation medias for either genomic or proteomic could clearly show the importance of this field.
  • Rapid analysis of oligosaccharides derived from glycoproteins by microchip electrophoresis.
    Fuquan Dang, Kazuaki Kakehi, Kazuki Nakajima, Yasuo Shinohara, Mitsuru Ishikawa, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Journal of Chromatography. A, 1109, 2, 138, 43, 2006年03月24日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), A novel method for fast profiling of complex oligosaccharides released from glycoproteins based on microchip electrophoresis (mu-CE) is presented here. The characterization of separation conditions, i.e., the composition, concentration and pH of running buffer as well as the applied voltage, has been performed using maltose (G2), cellobiose ( G2'), maltriose (G3) and panose (G3') as oligosaccharide isomer models. In mu-CE, much better separation of oligosaccharide isomers and oligosaccharide ladder was obtained in phosphate buffer than in borate buffer over a wide pH range. Under optimal conditions, high-performance separation of the N-linked complex oligosaccharides released from ribonuclease B, fetuin, alpha1-acid glycoprotein (AGP) and IgG was achieved using polymethylmethacrylate (PMMA) microchips with an effective separation channel of 30 mm. These results represent the first reported analysis of the N-linked oligosaccharides derived from glycoproteins by mu-CE, indicating that the present mu-CE-based method is a promising alternative for characterization of the N-linked oligosaccharides in glycoproteins.
  • Erratum: Development of the innovative nuclide separation system for high-level radioactive waste using microchannel chip - Extraction behavior of metal ions from aqueous phase to organic phase in microchannel (Progress in Nuclear Energy (2005) 47 (439-447) DOI: 10.1016/j.pnucene.2005.05.045)
    Hiroyasu Hotokezaka, Manabu Tokeshi, Masayuki Harada, Takehiko Kitamori, Yasuhisa Ikeda
    Progress in Nuclear Energy, 48, 2, 187, 2006年03月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Miniaturized thermal lens and fluorescence detection system for microchemical chips
    M Yamauchi, M Tokeshi, J Yamaguchi, T Fukuzawa, A Hattori, A Hibara, T Kitamori
    JOURNAL OF CHROMATOGRAPHY A, 1106, 1-2, 89, 93, ELSEVIER SCIENCE BV, 2006年02月, [査読有り]
    英語, 研究論文(学術雑誌), We have developed a miniaturized two-way detection system using thermal lens and fluorescence spectroscopies for microchip chemistry. The system was composed of laser diode (LD) modules, fiber-based optics combined with a gradient index lens. and miniaturized detection units for thermal lens and fluorescence signals. The detection limits in the thermal lens and fluorescence spectroscopies were 6.3 x 10(-9) M for Ni(II) phthalocyanine tetrasulfonic acid and 3.0 x 10(-9) M for cy5, respectively. The performance of the system with the miniaturized thermal lens was equivalent to that of a conventional thermal lens microscope. The fluorescence sensitivity was comparable to sensitivities offered by conventional miniaturized systems. (c) 2005 Elsevier B.V. All rights reserved.
  • Microchip-based rapid sample-preparation for gas-chromatography assay of amphetamine-type stimulants in urine specimens               
    Hajime Miyaguchi, Manabu Tokeshi, Yoshikuni Kikutani, Akihide Hibara, Hiroyuki Inoue, Takehiko Kitamori
    Micro Total Analysis Systems - Proceedings of MicroTAS 2006 Conference: 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 936, 938, Japan Academic Association Inc, 2006年
    英語, 研究論文(国際会議プロシーディングス), As the first application of pressure-driven microfluidics in forensic toxicology, a microchip-based liquid-liquid extraction for the gas-chromatography assay for amphetamine-type stimulants in urine has been developed. The interface consisting of 1-chlorobutane and alkalized urine was stabilized in the asymmetric microchannel modified partially with the capillarity restricted modification (CARM) method. As a practical demonstration, methoxyphenamine hydrochloride was administered to three healthy volunteers, and the concentration of methoxyphenamine in their urine was determined. © 2006 Society for Chemistry and Micro-Nano Systems.
  • Flowing thermal lens micro flow velocimeter with on-chip microlens and detachable optical fibers               
    Yoshikuni Kikutani, Kazuma Mawatari, Kenji Katayama, Yoshinori Matsuoka, Takashi Fukuzawa, Akihiko Hattori, Mitsuo Kitaoka, Manabu Tokeshi, Takehiko Kitamori
    Micro Total Analysis Systems - Proceedings of MicroTAS 2006 Conference: 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1271, 1273, Japan Academic Association Inc, 2006年
    英語, 研究論文(国際会議プロシーディングス), Flowing thermal lens micro flow velocimeter (FTL-MFV) is an optical detector for measurement of flow rate in microchannel without disturbing the microfluid. By using optical fibers and micro rod lenses, we have fabricated a series of small FTL-MFVs. In this paper, we report on a FTL-MFV with an on-chip microlens, that we newly developed to simplify optical alignment process needed for FTL-MFV measurements. Performance of FTL-MFV was also improved by using an on-chip microlens. © 2006 Society for Chemistry and Micro-Nano Systems.
  • Simulation examination for extraction on oil/water surface               
    Ryo Anraku, Takahiro Asai, Kenji Uchiyama, Akihiko Hattori, Manabu Tokeshi, Takehiko Kitamori
    Micro Total Analysis Systems - Proceedings of MicroTAS 2006 Conference: 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 798, 800, Japan Academic Association Inc, 2006年
    英語, 研究論文(国際会議プロシーディングス), In this study, we compared the extraction result on oil/water surface in a microchip between experiment and calculation. As a result, when the model considered flow was given the fitting constant as stopped flow experiment and computed, the extraction in the m-xylene at the channel exit became about half compared with the experiment value. © 2006 Society for Chemistry and Micro-Nano Systems.
  • Flow Analysis in Microchannels Using a Thermal Lens Microscope
    Manabu Tokeshi
    Shinku/Journal of the Vacuum Society of Japan, 49, 7, 400, 403, 2006年, [査読有り]
    英語, 研究論文(学術雑誌)
  • Radiation degradation of microchemical chips and capillary tubes by gamma-ray irradiation
    Hidematsu Ikeda, Manabu Tokeshi, Hiroyasu Hotokezaka, Yasuhisa Ikeda, Takehiko Kitamori
    Transactions of the Atomic Energy Society of Japan, 5, 3, 209, 220, Atomic Energy Society of Japan, 2006年, [査読有り]
    日本語, 研究論文(学術雑誌), Analytical equipment, which consists of a microchemical chip and a desktop-sized thermal lens microscope (DT-TLM), is being developed to analyze solutions in PUREX reprocessing of spent nuclear fuels. Radiation degradation by gamma-rays of the microchemical chip and capillary tubes used in this equipment were studied. The decreased thermal lens signal of a colored microchemical chip made of Pyrex (Corning#7740) glass by the irradiation can be corrected by using empirical correlations of the light transmittance. The usable dose of the EXLON PFA capillary tube was less than 30 kGy. The microchemical chip made of Pyrex (Corning#7740) glass and the EXLON PFA capillary tubes can be applied to the analyses of high radioactivity samples since the sample quantity required for analysis is very small. Radiation degradation of the microchemical chip made of synthetic quartz (SUPRASIL-P) and the VICTREX PEEK capillary tubes was not observed for the dose studied here. © Atomic Energy Society of Japan.
  • Microchemical chip technology and nuclear energy - To develop new analytical system for process control in reprocessing plant
    M Tokeshi, Y Ikeda, T Kitamori
    JOURNAL OF THE ATOMIC ENERGY SOCIETY OF JAPAN, 48, 1, 38, 43, ATOMIC ENERGY SOC JAPAN, 2006年01月, [査読有り]
    日本語, 研究論文(学術雑誌)
  • “UV-excitation thermal lens microscope for non-labeled and ultrasensitive detection of non-fluorescent molecules
    S. Hiki, K.Mawatari, A.Hibara, M.Tokeshi, T.Kitamori
    Analytical Chemistry, 8, 78, 2859, 2863, 2006年, [査読有り]
    英語, 研究論文(学術雑誌)
  • A new exploration in enhancing the resolutionfor high-performance analysis of mono-sulfate glycosaminoglycan disaccharide isomers on a poly(methyl methacrylate) chip
    Yong Zhang, Guichen Ping, Bingmei Zhu, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Micro Total Analysis Systems - Proceedings of MicroTAS 2006 Conference: 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 395, 397, 2006年, [査読有り]
    研究論文(国際会議プロシーディングス), The glycosaminoglycans (GAGs) labeled with 2-aminoacridone, hydrochloride (AMAC) were found to be prevented from adsorption to the surface of polymehylmethacrylate (PMMA) microchips by dynamic coating microchannel with methyl cellulose (MC). To obtain sufficient resolution of mono-sulfate GAG disaccharide isomers on microchip electrophoresis (MCE), buffer pH, β-cyclodextrin (β-CD), and 1,4-dioxane (DO) were systematically investigated. We found that the application of 1,4-dioxane (DO) dramatically improved the resolution of the analytes. ΔDi-triS, ΔDi-UA2S, ΔDi-4S, and ΔDi-6S were baseline separated within 75 sec. The theoretical plate was in the range of 5×105-1×10 6 m-1. © 2006 Society for Chemistry and Micro-Nano Systems.
  • Continuous-flow chemical processing in three-dimensional microchannel network for on-chip integration of multiple reactions in a combinatorial mode
    Yoshikuni Kikutani, Masaharu Ueno, Hideaki Hisamoto, Manabu Tokeshi, Takehiko Kitamori
    QSAR and Combinatorial Science, 24, 6, 742, 757, 2005年08月, [査読有り]
    英語, 研究論文(学術雑誌), Chemical syntheses using microchemical chips have been intensively investigated in recent years, but they have still not fully reached the stage of practical use. Combinatorial synthesis has been expected to be one of their useful applications. Benefits of using microchips, such as reduction in quantity of reagents and wastes, are thought to be suited for combinatorial syntheses, where numerous variations of products have to be synthesized each in small amounts. There are two modes of combinatorial syntheses using microchemical chips. One is sequential synthesis, in which reactant solutions are introduced sequentially in various combinations to a reaction microchannel. The other is parallel synthesis, where the number of reaction channels is the same as the number of final products, and starting materials are distributed to all the reaction channels in different combinations. Sequential synthesis has been considered as the more favorable way, because, especially when libraries of starting materials are large, numerous microchannels and complicated pipings for distribution of reagents to the channels are required for the parallel mode. Therefore, research on parallel microcombinatorial syntheses has been done only rarely, whereas there have been many reports of sequential microcombinatorial syntheses. Against this trend, our research group has taken an alternative path and tried to integrate both parallel reaction microchannels onto a glass microchip and channels for distributing reactant solutions to each reaction channel in a combinatorial mode. Microchips fabricated by laminating multiple layers of glass substrates have been used to construct three-dimensional microchannel networks necessary for mixing reagent flows in different combinations. We utilized low Reynolds number multi-phase laminar flow and developed micro-unit operations (MUOs). By combining MUOs in the multi-phase continuous laminar flows, microchemical systems were constructed. We called this micro-integration methodology "continuous-flow chemical processing (CFCP)", and by using it, a sequence of various operations in chemical syntheses could be integrated on a microchemical chip. Not just simple mixing of two reagents, which was most commonly done in microreactors, but also multi-step processes including other chemical operations, such as extraction and separation, could be carried out via CFCP. In the first part of this short review article, we explain CFCP with an example. Then, a microchemical chip with a three-dimensional microchannel network for a parallel reaction system is introduced. Finally, we present a case in which CFCP was realized in a three-dimensional microchannel network. © 2005 Wiley-VCH Verlag GmbH &
    Co. KGaA.
  • System for high-level radioactive waste using microchannel chip - Extraction behavior of metal ions from aqueous phase to organic phase in microchannel
    Hiroyasu Hotokezaka, Manabu Tokeshi, Masayuki Harada, Takehiko Kitamori, Yasuhisa Ikeda
    Progress in Nuclear Energy, 47, 1-4, 439, 447, 2005年07月, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), In order to clarify the extraction behavior of U(VI) from aqueous phase to organic one in microchannel, we have carried out extraction experiments of U(VI) from HNO3 aqueous solution of 3 M (M = mol/dm3) to 30% or 100% TBP phase in microchannel. From the results of extraction experiments, it was found that the extraction of U(VI) in microchannel could be performed in a short time for approximately 1 s with a good extractability in both organic phases of 30% and 100% TBP, and suggested that the other nuclides could be extracted with high extraction efficiency in microchannel. Furthermore, it is expected that the innovative and sophisticated nuclide separation systems can be developed by using microchannel extraction with selective extractants for specific nuclide. © 2005 Published by Elsevier Ltd. All rights reserved.
  • 集積化ガラスチップ
    渡慶次 学, 菊谷 善国
    表面技術 = The Journal of the Surface Finishing Society of Japan, 56, 3, 132, 137, The Surface Finishing Society of Japan, 2005年03月01日
    日本語
  • Surface modification method of microchannels for gas-liquid two-phase flow in microchips
    Akihide Hibara, Shinobu Iwayama, Shinya Matsuoka, Masaharu Ueno, Yoshikuni Kikutani, Manabu Tokeshi, Takehiko Kitamori
    Analytical Chemistry, 77, 3, 943, 947, 2005年02月01日, [査読有り]
    英語, 研究論文(学術雑誌), A capillarity restricted modification method for microchannel surfaces was developed for gas-liquid microchemical operations in microchips. In this method, a microstructure combining shallow and deep microchannels and the principle of capillarity were utilized for chemical modification of a restricted area of a microchannel. A hydrophobic-hydrophilic patterning in microchannels was prepared as an example for guiding gas and liquid flows along the respective microchannels. Validity of the patterning was confirmed by measuring aqueous flow leak pressure from the hydrophilic microchannel to the hydrophobic one. The leak pressure of 7.7-1.1 kPa agreed well with that predicted theoretically from the Young-Laplace equation for the microchannel depth of 8.6-39 μm. In an experiment to demonstrate usefulness and effectiveness of the method, an air bubble was first introduced into the hydrophilic microchannel and purged from the hydrophobic-hydrophilic patterned microchannels. Next, the patterning structure was applied to remove dissolved oxygen by contacting the aqueous flow with a nitrogen flow. The concentration of dissolved oxygen decreased with contact time, and its time course agreed well with numerical simulation. These demonstrations showed that the proposed patterning method can be used in general microfluidic gas-liquid operations.
  • Development of UV thermal lens microscope (UV-TLM) for ultrasensitive and direct detection of non-labeled biomolecules on a microchip               
    Manabu Tokeshi, Shinichiro Hiki, Kazuma Mawatari, Akihide Hibara, Takehiko Kitamori
    Micro Total Analysis Systems - Proceedings of MicroTAS 2005 Conference: 9th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1, 452, 454, Transducer Research Foundation, 2005年
    英語, 研究論文(国際会議プロシーディングス), This paper describes the development of an ultraviolet thermal lens microscope (UVTLM) that can detect directly non-labeled biomolecules in microchips. The performance of the UV-TLM was evaluated by the limit of detection (LOD) using standard solution of adenine. The LOD for adenine was calculated to be 1.4×10-8 M. This sensitivity was 100 times higher than that obtained by conventional spectrophotometry. Copyright © 2005 by the Transducer Research Foundation, Inc.
  • Development of novel non-contact and in-situ microflow sensor using flowing thermal lens               
    Yoshikuni Kikutani, Kazuma Mawatari, Manabu Tokeshi, Takashi Fukuzawa, Mitsuo Kitaoka, Takehiko Kitamori
    Micro Total Analysis Systems - Proceedings of MicroTAS 2005 Conference: 9th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1, 970, 972, Transducer Research Foundation, 2005年
    英語, 研究論文(国際会議プロシーディングス), Newly developed flowing thermal lens microflow velocimeter, in which photothermally produced local refractive index change was used as a tracer of micro flow, enabled noncontact and in-situ measurement of flow inside a microchemical chip. Characteristics of the flow sensor were investigated. Copyright © 2005 by the Transducer Research Foundation, Inc.
  • Development of hybrid detection system for simultanious detection of thermal lens and fluorescence signals               
    Jun Yamaguchi, Takashi Fukuzawa, Akihiko Hattori, Manabu Tokeshi, Takehiko Kitamori
    Micro Total Analysis Systems - Proceedings of MicroTAS 2005 Conference: 9th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1, 967, 969, Transducer Research Foundation, 2005年
    英語, 研究論文(国際会議プロシーディングス), We developed a sensitive and small detection system which can measure both fluorescence and thermal lens signals at the same time. In the detection system, the object lens has three functions (irradiation lens and condenser lens for fluorescence measurement and object lens for thermal lens measurement). As a result, it became very easy to change the measurement position on the chip. The detection system here had good performance. The limit of determination was 4.7x10-9 mol/L and 4.4x10-9 mol/L respectively. Copyright © 2005 by the Transducer Research Foundation, Inc.
  • Circular dichroism thermal lens microscope for sensitive and selective detection of chiral samples on microchip               
    Kazuma Mawatari, Masayo Yamauchi, Akihide Hibara, Manabu Tokeshi, Takehiko Kitamori
    Micro Total Analysis Systems - Proceedings of MicroTAS 2005 Conference: 9th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1, 1035, 1037, Transducer Research Foundation, 2005年
    英語, 研究論文(国際会議プロシーディングス), Thermal lens microscope (TLM) is a kind of absorption spectrometry with a sensitivity of single molecules in fL detection volume. In this paper, we report a newly functionalized TLM for selective and sensitive detection of chiral samples. We developed a circular dichroism (CD) thermal lens microscope by light phase modulation. We verified the basic principle and achieved two orders higher sensitivity than CD spectrometer. Copyright © 2005 by the Transducer Research Foundation, Inc.
  • Application of flowing thermal lens to flow sensors for microchemical chips
    Yoshikuni Kikutani, Keisuke Morishima, Manabu Tokeshi, Jun Yamaguchi, Takashi Fukuzawa, Akihiko Hattori, Yoshikazu Yoshida, Mitsuo Kitaoka, Takehiko Kitamori
    Digest of Technical Papers - International Conference on Solid State Sensors and Actuators and Microsystems, TRANSDUCERS '05, 1, 380, 383, 2005年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), Flowing thermal lens microflow velocimeter, in which photothermally produced local refractive index change (a thermal lens) was used as a tracer, was developed for microchemical chips made of glass. A laser pulse was focused with a microlens on a liquid flow inside a microchannel, and a thermal lens was produced. The thermal lens drifted downstream and was detected by using another beam. Velocity was calculated from the time required for the thermal lens to travel between the two points. The microflow velocimeters enabled non-contact measurement with only slight disturbance to the microfluid possible and were suitable for microchemical systems. © 2005 IEEE.
  • Tunable thermal lens spectrometry utilizing microchannel-assisted thermal lens spectrometry
    Eiichiro Tamaki, Akihide Hibara, Manabu Tokeshi, Takehiko Kitamori
    Lab on a Chip, 5, 2, 129, 131, Royal Society of Chemistry, 2005年, [査読有り]
    英語, 研究論文(学術雑誌), A tunable thermal lens spectrometry system was developed for microchip analysis. The system utilized a Xe lamp as an excitation source, instead of a laser. The system can measure the absorption spectrum of a turbid solution without disturbance of the light scattering background.
  • Packed channel HPLC on microchips
    K Okubo, M Tokeshi, Y Yoshida, T Kitamori
    Micro Total Analysis Systems 2004, Vol 1, 296, 162, 164, SPRINGER, 2005年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), Integration of HPLC on microchips were tried in a few reports, but it was difficult to realize pressure driven HPLC systems on-chip. We have developed high-pressure proof microfluidic devises and succeeded in integrating packed channel HPLC systems on microchips. Two types of high-pressure proof micro connectors and two types of column termination frits were developed, and performance of packed-channel HPLC systems based on those microfluidic devises was evaluated using standard samples.
  • Continuous flow chemical processing on a microchip using microunit operations and a multiphase flow network
    M Tokeshi, T Kitamori
    PROGRESS IN NUCLEAR ENERGY, 47, 1-4, 434, 438, PERGAMON-ELSEVIER SCIENCE LTD, 2005年, [査読有り]
    英語, 研究論文(学術雑誌), The new methodology for integration of chemical processing on a microchip was proposed. This methodology, continuous flow chemical processing (CFCP), is based on a combination of microunit operations (MUOs) and a multiphase flow network. Chemical operations in microchannels, such as mixing, reaction, and extraction, were classified into several MUOs. The complete procedure for Co(II) wet analysis, including a chelating reaction, solvent extraction, and purification was decomposed into MUOs and reconstructed as CFCP on a microchip. Chemical reaction and molecular transport were realized in and between continuous liquid flows in a multiphase flow network, such as aqueous/aqueous, aqueous/organic, and aqueous/organic/aqueous flows. (C) 2005 Elsevier Ltd. All rights reserved.
  • Optimization of an interface chip for coupling capillary electrophoresis with thermal lens microscopic detection
    K Uchiyama, M Tokeshi, Y Kikutani, A Hattori, T Kitamori
    ANALYTICAL SCIENCES, 21, 1, 49, 52, JAPAN SOC ANALYTICAL CHEMISTRY, 2005年01月, [査読有り]
    英語, 研究論文(学術雑誌), This paper presents a capillary-to-microchip connection, which can be used as an interface for coupling Capillary electrophoresis (CE) with a thermal lens microscope (TLM). It is difficult to directly apply TLM to samples in a capillary with a curved surface, and such an interface chip at the end of a CE separation column is needed for reliable TLM measurements. The dependence of the TLM signal intensity on the TLM detection point in the interface chip and the dependence of the theoretical plate number of CE separation on the channel dimensions of the interface chip were, investigated and optimized with a mixture of 4-dimethylaminoazobenzene-4'-sulfonyl(DABSYL)-derivatized amino acids (glycine, alanine, methionine, and proline) as a model sample. By using an optimized inter-face chip. theoretical plate numbers of DABSYL-glycine, -methionine, -alanine, and -pro line were obtained to be 104000, 95000, 104000, and 95000, respectively.
  • Effect of Korteweg stress in miscible liquid two-layer flow in a microfluidic device
    Y Sugii, K Okamoto, A Hibara, M Tokeshi, T Kitamori
    JOURNAL OF VISUALIZATION, 8, 2, 117, 124, IOS PRESS, 2005年, [査読有り]
    英語, 研究論文(学術雑誌), Miscible liquid two-layer flow in a Y-shaped microfluidic device, which consists of microchannels with 120 mu m in width and 35 mu m in depth, is investigated by particle image velocimetry (PIV) to clarify the flow characteristics at fluid interfaces. The obtained velocities with a spatial resolution of 5.9 x 1.5 mu m(2) around the interface between water and ethanol indicate an imbalance in shear stress at interface. The reason of the imbalance is to be the Korteweg stress generated by interfacial tension gradient due to a concentration gradient by diffusion in a miscible two-layer flow. The stress may cause an interfacial instability and destroy a uniform mixing in two flowing fluids in the case of large concentration gradient.
  • Interchannel microstructure for separation and analyses of plasma from whole blood
    XH Yang, A Hibara, K Sato, M Tokeshi, K Morishima, Y Kikutani, H Kimura, T Kitamori
    Micro Total Analysis Systems 2004, Vol 1, 296, 120, 122, SPRINGER, 2005年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), A microstructure similar to cross-flow micro-filter was developed for separation of plasma from whole blood without centrifugation, which consists of many shallow channels, like micro pores, located between two bigger channels (main channels), and acted as passages of plasma but dams for blood cells. Plasma without obvious hemolysis could be observed in main channels within 3 min. Such a microstructure has the potential to combine or integrate with other types of microstructure to form on-chip blood analyses devices. As a model, integrated with on-chip bead-bed immunoassay, a microchip was used for the determination of human alpha-fetoprotein on the range of 5-600 ng/mL.
  • Experimental and numerical study of korteweg stress in continuous flow chemical processing on microchip
    Y Sugii, K Okamoto, A Hibara, M Tokeshi, T Kitamori
    Micro Total Analysis Systems 2004, Vol 1, 296, 228, 230, SPRINGER, 2005年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), Miscible liquid two-layer flow in a Y-shaped microfluidic device with 120 Pm in width and 33 mu m in depth, is investigated using particle image velocimetry (PIV) to clarify the flow characteristics at fluid interfaces. The obtained velocities with a spatial resolution of 5.9 x 1.5 mu m(2) around the interface between water and ethanol indicate an imbalance in shear stress at interface. The numerical simulation based on the Korteweg stress generated by interfacial tension gradient was carried out. The stress may cause an interfacial instability and destroy a uniform mixing in two flowing fluids in the case of large concatenation gradient.
  • Capillarity-restricted modification method for gas/liquid separation and gas bubble purge in microchannels
    A Hibara, S Iwayama, M Ueno, Y Kikutani, M Tokeshi, T Kitamori
    Micro Total Analysis Systems 2004, Vol 1, 296, 557, 559, SPRINGER, 2005年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), A surface modification control method for microchannels was developed for gas-liquid microchemical operations in microchips. In this method, shallow and deep microchannels were modified with hydrophobic and hydrophilic groups, respectively. This patterning was prepared based on principle of capillarity. Validity of the patterning was confirmed by measuring aqueous flow leak pressure from the hydrophilic microchannel to the hydrophobic one. The leak pressure agreed well with theoretical prediction from Young-Laplace equation. In order to demonstrate usefulness and effectiveness of the method, air bubble was introduced to the hydrophilic microchannel and purged from the hydrophobic-hydrophilic patterned microchannels. Next, the patterning structure was applied to remove dissolved oxygen by contacting the aqueous flow with nitrogen-flow. The concentration of dissolved oxygen decreased with contact time and its time course agreed well with numerical simulation. These demonstrations showed that the proposed patterning method is promising to general microfluidic gas-liquid operations.
  • Thermal lens micro optical systems
    M Tokeshi, J Yamaguchi, A Hattori, T Kitamori
    ANALYTICAL CHEMISTRY, 77, 2, 626, 630, AMER CHEMICAL SOC, 2005年01月, [査読有り]
    英語, 研究論文(学術雑誌), This paper describes two types of miniaturized thermal lens optical systems that use optical fibers, SELFOC microlenses and light sources. The first system consists of a compact diode pumped solid-state laser (532 nm) as an excitation light source, a laser diode (635 nm) as a probe light source, an acoustoptic modulator as an excitation light modulator, fiber-based and conventional optics, and a detection system that combines a pinhole, an interference filter, and a photodiode. The second system consists of two laser diodes as the excitation (658 nm) and probe (780 nm) light sources, fiber-based optics, and the same detection system as the first one. The performance of the two systems was evaluated by the limit of detection (LOD) using standard solutions of sunset yellow (SY) and nickel(II) phthalocyaninetetrasulfonic acid tetrasodium salt (NiP). The LODs of the first system for SY and second system for NiP were calculated to be 3.7 x 10(-8) (1.7 x 10(-6) AU) and 7.7 x 10(-9) M (3.4 x 10(-6) AU), respectively. These results were consistent with the expected values obtained from photothermal parameters.
  • Pressure-driven flow control and chemical reaction in nanochannels
    E Tamaki, A Hibara, HB Kim, M Tokeshi, T Ooi, M Nakao, T Kitamori
    Micro Total Analysis Systems 2004, Vol 1, 296, 318, 320, SPRINGER, 2005年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), A pressure-driven flow control scheme for nano chemical reactor was developed. For control the pressure of flow, we utilized a back pressure regulator and U-shaped microchannel. Based on this scheme, we fabricated a nano chemical reactor including a Y-shaped nanochannel for reaction and an U-shaped microchannel for liquid introduction. After combining the nano chemical reactor and back pressure regulators, we confirmed that the system worked properly with the pressure up to 7 MPa. By utilizing this system, chemical reaction in nanospace is realized.
  • Rapid proton diffusion in microfluidic devices by means of micro-LIF technique
    K Shinohara, Y Sugii, A Hibara, M Tokeshi, T Kitamori, K Okamoto
    EXPERIMENTS IN FLUIDS, 38, 1, 117, 122, SPRINGER, 2005年01月, [査読有り]
    英語, 研究論文(学術雑誌), The micro-LIF (laser-induced fluorescence) technique was applied to the measurement of pH distributions in a chemically reacting flow in a microfluidic device. Two liquid streams were combined at the junction of a Y-shaped microchannel (100-mum width and 33-mum depth), and allowed to diffuse into each other and react. The results for non-reacting fluids (hydrochloric acid and water) show good agreement with theoretical values calculated using conventional diffusion. When a reaction occurred (hydrochloric acid and sodium hydroxide), a large difference between the measurement results and the theoretical values was observed, indicating rapid proton diffusion compared with the theoretically calculated values.
  • Tunable thermal lens spectrometry utilizing microchannel-assisted thermal lens spectrometry
    E Tamaki, A Hibara, M Tokeshi, T Kitamori
    LAB ON A CHIP, 5, 2, 129, 131, ROYAL SOC CHEMISTRY, 2005年, [査読有り]
    英語, 研究論文(学術雑誌), A tunable thermal lens spectrometry system was developed for microchip analysis. The system utilized a Xe lamp as an excitation source, instead of a laser. The system can measure the absorption spectrum of a turbid solution without disturbance of the light scattering background.
  • Individual nano-particles detection on microchip by thermal lens microscope
    K Mawatari, S Hiki, A Hibara, M Tokeshi, T Kitamori
    Micro Total Analysis Systems 2004, Vol 2, 297, 434, 436, ROYAL SOC CHEMISTRY, 2005年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), Thermal lens microscope (TLM) is an ultra-sensitive method for detecting non-fluorescent samples in microspace. TLM is a kind of optical absorption spectrophotometry with comparable sensitivity to the laser induced fluorescence method. In this presentation, the applicability of TLM was extended from visible to ultraviolet (UV) light absorbing samples by UV laser excitation. The flow velocity was investigated for optimizing the sensitivity. The detection limit of 9.2 x 10-7 in absorbance unit was obtained and about 2 orders of magnitude superior to spectrophotometry: In addition, TLM was further developed for individual nanoparticles counting with visible laser excitation. Individual gold nanoparticles of 15 nm in diameter could be detected, and the detection limit of 5 nm, that was about 1 order lower in diameter than laser scattering method, was obtained.
  • Development of a Microchip-Based Bioassay System Using Cultured Cells               
    Makiko Goto, Kiichi Sato, Atsushi Murakami, Manabu Tokeshi, Takehiko Kitamori
    Analytical Chemistry, 77, 2125, 2131, 2005年
  • High-speed micro-PIV measurements of transient flow in microfluidic devices
    K Shinohara, Y Sugii, A Aota, A Hibara, M Tokeshi, T Kitamori, K Okamoto
    MEASUREMENT SCIENCE AND TECHNOLOGY, 15, 10, 1965, 1970, IOP PUBLISHING LTD, 2004年10月, [査読有り]
    英語, 研究論文(学術雑誌), This paper reports a new technique of micro-resolution particle image velocimetry (PIV). To investigate transient phenomena in a microfluidic device, a high-speed micro-PIV technique was developed by combining a high-speed camera and a continuous wave (CW) laser. The technique was applied to a micro counter-current flow, consisting of water and butyl acetate. The velocity fields of water in the micro counter-current flow were visualized for a time resolution of 500 mus and a spatial resolution of 2.2 x 2.2 mum(2). Using the micro-PIV technique, the vortex-like motions of fluorescent particles around the water-butyl acetate interface were captured clearly.
  • Measurement of pH field of chemically reacting flow in microfluidic devices by laser-induced fluorescence
    K Shinohara, Y Sugii, K Okamoto, H Madarame, A Hibara, M Tokeshi, T Kitamori
    MEASUREMENT SCIENCE AND TECHNOLOGY, 15, 5, 955, 960, IOP PUBLISHING LTD, 2004年05月, [査読有り]
    英語, 研究論文(学術雑誌), The interaction between chemical reactions and the flow field in microfluidic devices is investigated by a laser-induced fluorescence technique refined for use at microscopic spatial resolution. The pH distribution of chemically reacting flow at a Y-junction in a neutralization reaction in a microfluidic device is successfully visualized at a spatial resolution of 0.89 mum x 0.89 mum.
  • Thermal lens microscopy and microchip chemistry
    T Kitamori, M Tokeshi, A Hibara, K Sato
    ANALYTICAL CHEMISTRY, 76, 3, 52A, 60A, AMER CHEMICAL SOC, 2004年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Fabrication of bio microactuator using cultured cardiomyocytes and PDMS microstructures
    Y. Tanaka, K. Morishima, M. Ebara, T. Shimizu, M. Yamato, M. Tokeshi, T. Okano, T. Kitamori
    Transactions - 7th World Biomaterials Congress, 1357, 2004年
    研究論文(国際会議プロシーディングス), Microstructures of Poly dimethyl siloxane (PDMS) were driven by cultured cardiomyocytes of neonatal rats. The motion of PDMS micropillars actuated by cardiomyocytes, their force, and the mechanisms by which they attach to pillars were studied. Using scanning electron micrography, it was found that cardiomyocytes attach to the top of a pillar with a beating time of one in three seconds. The force of the cardiomyocytes was found to be about a few μN.
  • Microchip-based enzyme-linked immunosorbent assay (microELISA) system with thermal lens detection
    Kiichi Sato, Maho Yamanaka, Tomokazu Hagino, Manabu Tokeshi, Hiroko Kimura, Takehiko Kitamori
    Lab on a Chip, 4, 6, 570, 575, Royal Society of Chemistry, 2004年, [査読有り]
    英語, 研究論文(学術雑誌), A microchip-based enzyme-linked immunosorbent assay (microELISA) system was developed and interferon-γ was successfully determined. The system was composed of a microchip with a Y-shaped microchannel and a dam structure, polystyrene microbeads, and a thermal lens microscope (TLM). All reactions required for the immunoassay were done in the microchannel by successive introduction of a sample and regents. The enzyme reaction product, in a liquid phase, was detected downstream in the channel using the TLM as substrate solution was injected. The antigen-antibody reaction time was shortened by the microchip integration. The limit of the determination was improved by adopting the enzyme label. Moreover, detection procedures were greatly simplified and required time for the detection was significantly cut. The system has good potential to be developed as a small and automated high throughput analyzer.
  • Micro wet analysis system using multi-phase laminar flows in three-dimensional microchannel network
    Yoshikuni Kikutani, Hideaki Hisamoto, Manabu Tokeshi, Takehiko Kitamori
    Lab on a Chip, 4, 4, 328, 332, Royal Society of Chemistry, 2004年, [査読有り]
    英語, 研究論文(学術雑誌), A three-dimensional microchannel network with two-level crossings of channels was constructed in a glass microchip by sandwiching an insulating glass plate between two glass plates with microchannels followed by thermal bonding. Pressure-driven stable multi-phase laminar flows inside the three-dimensional channel network were realized by balancing flow rates of syringe pumps. Micro unit operations for mixing, reaction, solvent extraction, and detection were properly arranged in the multi-phase laminar flows, so that four parallel analyses, comprising twenty unit operations in total, could be integrated onto a single chip. Two chelating reagents and two sample solutions containing heavy metal ions (Fe(II) or Co(II)) were mixed and reacted in four different combinations using the three-dimensional channel network. After chelating reactions were completed, post processing (solvent extraction or addition of acid) was applied to each solution stream to remove the interferences of coexisting metal ions. Finally, target metal complexes were detected using a thermal lens microscope (TLM). Integrity of the micro system was confirmed by qualitative analysis of Fe(II) and Co(II). This is the first example of continuous flow chemical processing utilizing multi-phase laminar flow realized in a three-dimensional channel network.
  • Gas-liquid crossing flow in microchannel and its application to gas analysis microchip
    H Hachiya, M Tokeshi, Y Yoshida, T Kitamori
    PROCEEDINGS OF THE IEEE SENSORS 2004, VOLS 1-3, 166, 169, IEEE, 2004年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), We developed a novel microchannel structure comprised of deep/shallow/deep three-channels. Each end of the channel was split into three, and supplying and taking of fluids to/from the channels were possible. Aqueous solution tended to fill the shallow channel because of the capillary force. Thus by introducing gas/liquid/gas from one end of the channel, stable laminar three-phase flow was formed throughout the channel. We introduced liquid/gas/liquid to the channels then. The flow became turbulent, near the confluence, and settled into gas/liquid/gas laminar profile at downstream. The channel-design and flow rates were optimized to form this gas-liquid crossing flow continuously. The gas-liquid crossing flow was useful in micro-analysis and synthesis, because efficient gas-liquid contact at the turbulence promote extraction and reaction, and spontaneous separation of the two phases enabled post processes (e.g. detection). The crossing flows were also formed at the other microchannel-structures like a shallow/deep/shallow three channels and a deep/shallow two channels.
    A sensor for low-concentration ammonia gas by using this structure was also reported in this paper.
  • Micro wet analysis system using multi-phase laminar flows in three-dimensional microchannel network
    Y Kikutani, H Hisamoto, M Tokeshi, T Kitamori
    LAB ON A CHIP, 4, 4, 328, 332, ROYAL SOC CHEMISTRY, 2004年, [査読有り]
    英語, 研究論文(学術雑誌), A three-dimensional microchannel network with two-level crossings of channels was constructed in a glass microchip by sandwiching an insulating glass plate between two glass plates with microchannels followed by thermal bonding. Pressure-driven stable multi-phase laminar flows inside the three-dimensional channel network were realized by balancing flow rates of syringe pumps. Micro unit operations for mixing, reaction, solvent extraction, and detection were properly arranged in the multi-phase laminar flows, so that four parallel analyses, comprising twenty unit operations in total, could be integrated onto a single chip. Two chelating reagents and two sample solutions containing heavy metal ions (Fe(II) or Co(II)) were mixed and reacted in four different combinations using the three-dimensional channel network. After chelating reactions were completed, post processing ( solvent extraction or addition of acid) was applied to each solution stream to remove the interferences of coexisting metal ions. Finally, target metal complexes were detected using a thermal lens microscope (TLM). Integrity of the micro system was confirmed by qualitative analysis of Fe( II) and Co( II). This is the first example of continuous flow chemical processing utilizing multi-phase laminar flow realized in a three-dimensional channel network.
  • Spectroscopic analysis of liquid/liquid interfaces in multiphase microflows
    A Hibara, M Nonaka, M Tokeshi, T Kitamori
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 125, 49, 14954, 14955, AMER CHEMICAL SOC, 2003年12月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Development of a desktop-sized thermal lens microscope
    S Hiki, M Tokeshi, A Hibara, T Kitamori
    BUNSEKI KAGAKU, 52, 8, 569, 574, JAPAN SOC ANALYTICAL CHEMISTRY, 2003年08月, [査読有り]
    日本語, 研究論文(学術雑誌), A desktop-sized thermal lens microscope (DT-TLM) having high sensitivity and wide applicability was developed. The operationality of the DT-TLM compared with that of a big-sized TLM has been remarkably improved by simplifying the optics and optimizing the optical configuration. In order to evaluate the performance, the DT-TLM was applied to the ultrasensitive detection of a non-fluorescent molecule (dye: Sunset Yellow) in water. The concentration dependence of the thermal lens signal (calibration curve) showed good linearity in the range of 1 x 10(-8)similar to1 x 10(-7) M. From the value of twice the standard deviation (2sigma) of this calibration curve, the lower limit of the quantitative determination was estimated to be 1.10 x 10(-8) M. The lower limit of detection was estimated as 8.27 x 10(-9) M from the conditions of the signal-to-noise ratio S/N=2. These obtained values were almost the same as that of the big-sized TLM.
  • Optimisation of thermal lens microscopic measurements in a microchip
    Mikhail A. Proskurnin, Maksim N. Slyadnev, Manabu Tokeshi, Takehiko Kitamori
    Analytica Chimica Acta, 480, 1, 79, 95, Elsevier, 2003年03月17日, [査読有り]
    英語, 研究論文(学術雑誌), The thermal lens optical scheme-design was optimised for microscopic measurements in microchannels. The efficient pathlength of the sample, irradiated volume, and the diameter of the thermal lens were estimated. Experimental time curves of development of the thermal lens and periodical oscillations of the signal due to convectional heat transfer are in good agreement with the theoretically expected behaviour. Noise sources (laser noises, instrumental flicker noise, convection, and flow noise) were studied. The possible effect of probe laser power on transient and steady-state thermal lens measurements were estimated. The effect of solvent absorption on the performance characteristics is shown. Under the optimum optical scheme-design, the limits of detection of ferroin and Sunset Yellow FCF at 488.0nm are 1×10-8 and 4×10-9moldm-3, respectively (corresponding quantities in the detection volume are 3×10-21 and 1×10-21mol). The total linear calibration range is n×10-8 to n×10-4moldm-3, the repeatability R.S.D. for this range is 3-7%. The optimised instrument was also used for the determination of characteristic rate constants of formation and dissociation of ferroin at the level of n × 10-8moldm-3. Some analytical applications are discussed. © 2003 Published by Elsevier Science B.V.
  • Microchannel-assisted thermal-lens spectrometry for microchip analysis
    E Tamaki, A Hibara, M Tokeshi, T Kitamori
    JOURNAL OF CHROMATOGRAPHY A, 987, 1-2, 197, 204, ELSEVIER SCIENCE BV, 2003年02月, [査読有り]
    英語, 研究論文(学術雑誌), Microchannel-assisted thermal lens spectrometry (MATLS) was developed for microchip analysis. This method utilized a photothermal effect in a very small space and rapid thermal conduction between a solid-liquid interface to produce a temperature gradient in the microchannel. In order to examine the mechanism experimentally, we constructed a detection system of laser defocus setup in which an excitation beam was not tightly focused, but it irradiated the microchannel homogeneously. The signal intensity dependence on modulation frequency of excitation and on solvent was investigated with the laser defocusing setup. The results of this investigation indicated that the mechanism of MATLS worked as expected. Since the mechanism of MATLS does not require directivity and coherence of the laser beam, other incoherent light sources can be used as excitation light for sensitive detections. Finally, we considered some future applications utilizing the mechanism. (C) 2002 Elsevier Science B.V. All rights reserved.
  • Fundamental Study on the Segmented Flow Injection - Multiphase Flow Formation Towards Microchip-Based Multi-Ion Sensing
    Hideaki Hisamoto, Takayuki Horiuchi, Akihide Hibara, Manabu Tokeshi, Takehiko Kitamori
    IEEJ Transactions on Sensors and Micromachines, 123, 4, 124, 127, 2003年, [査読有り]
    英語, 研究論文(学術雑誌), A new fluid flow inside the microchannel was successfully developed. The flow created here involves segmented flow injection of plural organic phases into a microchannel followed by contact with a single aqueous phase to form stable organic-aqueous two-layer flow inside the microchannel. Fundamental study on the developed flow inside the microchannel was performed by monitoring the dye-doped segmented organic phases by thermal lens microscopy (TLM). Excellent repeatability and very small injection volume in developing segmented flow were realized. The new fluid flow created here is expected to allow us multi-ion sensing, which is not easily demonstrated by conventional ion sensor technology using a solvent polymeric membrane, by combining with neutral ionophore-based ion pair extraction using plural numbers of organic phases containing different ionophore molecules. Keywords : Segmented flow injection, Microchip, μ-TAS, Multi-ion, Multiphase flow. © 2003, The Institute of Electrical Engineers of Japan. All rights reserved.
  • Micro integrated chemical systems for general use
    Yoshikuni Kikutani, Akihide Hibara, Hideaki Hisamoto, Manabu Tokeshi, Takehiko Kitamori
    Lab-on-a-Chip: Miniaturized Systems for (Bio) Chemical Analysis and Synthesis, 285, 307, Elsevier Inc., 2003年, [査読有り]
    英語, 論文集(書籍)内論文, This chapter provides information on micro and nano-fabrication technologies that have been introduced into chemical and biotechnologies. It also explains molecular and energy transport between multiphase laminar flow in a micro channel. As for chemical synthesis, micro reactors with sub-millimeter-sized micro channels are now eagerly investigated. Though there are some examples of electrokinetically-driven flow control in micro reactors, pressure-driven flow control is more commonly used for micro reactors. The aim is to develop methodology to integrate as many chemical processes as possible on microchips and to make full use of characteristics of micro space. Therefore, pressure-driven flow and developed techniques to operate chemical processing in pressure-driven laminar flow in micro channels are selected and for this microchips made of glass are used. Glass vessels are commonly used in many chemical experiments because of their chemical inertness and optical transparency. In order to realize these micro chemical systems based on multiphase laminar flow, some stabilization techniques for the multiphase flow has been inevitable. A micro channel with guide structures and surface modification to stabilize multiphase flows has been used. The chapter also presents a micro integration methodology, continuous flow chemical processing (CFCP), based on spontaneous motion of molecules in multi-phase laminar flow network in micro channel circuits. © 2003 Elsevier B.V. All rights reserved.
  • Chemicofunctional membrane for integrated chemical processes on a microchip
    H Hisamoto, Y Shimizu, K Uchiyama, M Tokeshi, Y Kikutani, A Hibara, T Kitamori
    ANALYTICAL CHEMISTRY, 75, 2, 350, 354, AMER CHEMICAL SOC, 2003年01月, [査読有り]
    英語, 研究論文(学術雑誌), Here we report a design and synthesis of a chemically functional polymer membrane by an interfacial polycondensation reaction and multilayer flow inside a microchannel. Single and parallel dual-membrane structures are successfully prepared by using organic/aqueous two-layer flow and organic/aqueous/organic three-layer flow inside the microchannel followed by an interfacial polycondensation reaction. By using the inner-channel membrane, permeation of ammonia species through the inner-channel membrane is successfully achieved. Furthermore, horseradish peroxidase is immobilized on one side of the membrane surface to integrate the chemical transform function onto the inner-channel membrane. Here substrate permeation through the membrane and subsequent chemical transformation at the membrane surface are realized. The polymer membrane prepared inside the microchannel has an important role in ensuring stable contact of different phases such as gas/liquid or liquid/liquid and the permeation of chemical species through the membrane. Furthermore, membrane surface modification chemistry allows chemical transformation of permeated chemical species. These methods are expected to lead to development of complicated and sophisticated chemical systems involving membrane permeation and chemical reactions.
  • An interface chip connection between capillary electrophoresis and thermal lens microscope
    K Uchiyama, A Hibara, K Sato, H Hisamoto, M Tokeshi, T Kitamori
    ELECTROPHORESIS, 24, 1-2, 179, 184, WILEY-V C H VERLAG GMBH, 2003年01月, [査読有り]
    英語, 研究論文(学術雑誌), A thermal lens microscope (TLM) detection of capillary electrophoresis (CE) utilizing microchip technology was developed. Fused-silica capillaries with an inner diameter of 50 pm were directly connected to a microchannel in a microchip. The detection limit by TLM was estimated as 2.8 x 10(-7) absorbance by measuring pure water. The detection limit of derivatized amino acids determined by CE-TLM was estimated as 2.4 x 10(-8) M, which was 100 times lower than that of conventional absorbance detection.
  • Integrated chemical systems on microchips for analysis and assay. Potential future, mobile high-performance detection system for chemical weapons
    Yoshikuni Kikutani, Manabu Tokeshi, Kiichi Sato, Takehiko Kitamori
    Pure and Applied Chemistry, 74, 12, 2299, 2309, Walter de Gruyter GmbH, 2002年12月01日, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), By analogy to unit operations (e.g., mixers, reactors, etc.) used in conventional chemical engineering, the concept of microunit operations permits the integration of complicated chemical systems onto a small microchip. A protocol for fabrication of such microchips is described, and its use is illustrated in several examples. In addition, the thermal lens microscope, which determines nonfluorescent species at the single-molecule level, is indispensable as an ultrasensitive detector for general use. Applications of microchip technology are given for chemical analysis, immunoassay, and full bioassay. Microchip analysis can provide very large enhancements in sensitivity and substantial reductions in measurement time as compared with conventional analytical methods.
  • Nanochannels on a fused-silica microchip and liquid properties investigation by time-resolved fluorescence measurements
    A Hibara, T Saito, HB Kim, M Tokeshi, T Ooi, M Nakao, T Kitamori
    ANALYTICAL CHEMISTRY, 74, 24, 6170, 6176, AMER CHEMICAL SOC, 2002年12月, [査読有り]
    英語, 研究論文(学術雑誌), We have fabricated nanometer-sized channels, demonstrated a technique for the introduction of liquid into the channels, and carried out time-resolved fluorescence measurements of aqueous solutions. In this study, 330-nm- and 850-nm-sized channels were fabricated on fused-silica substrates by fast atom beam etching and hydrofluoric acid bonding methods. A liquid introduction method utilizing capillary action was demonstrated. The liquid introduction was observed under an optical microscope, and the liquid velocity during the introduction was analyzed by surface energy and macroscale hydrodynamics. The liquid velocity due to capillary action in the nanometer-sized channel seemed more than four times slower than the estimation. Then, aqueous solutions of rhodamine 6G (R6G), sulforhodamine 101 (SR101), and rhodamine B (RB) in the channels were measured by time-resolved fluorescence spectroscopy; spectra of the same solution in a 250-mum-sized channel were also measured as a reference for the macrospace. Although the fluorescence spectra in the 330-nm-, 850-nm- and 250-mum-sized channels agreed with one another, the fluorescent decays in the nanometer-sized channels were faster for R6G and SR101 and slower for RB than the respective decays in the 250-mum-sized channels. The results suggested the solutions had lower dielectric constants and higher viscosities in the nanometer-sized channels.
  • Pile-up glass microreactor
    Yoshikuni Kikutani, Akihide Hibara, Kenji Uchiyama, Hideaki Hisamoto, Manabu Tokeshi, Takehiko Kitamori
    Lab on a Chip, 2, 4, 193, 196, Royal Society of Chemistry, 2002年11月01日, [査読有り]
    英語, 研究論文(学術雑誌), We made a 'pile-up' microreactor in which ten levels of microchannel circuits were integrated to form a single glass entity. Solutions were distributed to each layer via cylindrical holes with a diameter much larger than that of the microchannel. Fabrication of the pile-up reactor was completed using only conventional photolithography, wet etching and thermal bonding techniques, and no special facilities or instruments were required. An amide formation reaction between amine in aqueous solution and acid chloride in organic solution was carried out using the pile-up reactor. The yield of the amide formation reaction is dependent on the size of the specific surface area between the two solutions, and the small space inside the microchannels is good for acquiring a large specific surface area without any stirring processes. The maximum throughput for the ten-layered pile-up reactor was ten times larger than that of a single-layered one, yet the reaction yield was still high. Productivity of the pile-up reactor for the reaction was as high as on a gram per hour scale. This value suggests that many conventional plants producing fine chemicals can be replaced by microreactors through the numbering-up technology.
  • Glass microchip with three-dimensional microchannel network for 2 × 2 parallel synthesis
    Yoshikuni Kikutani, Takayuki Horiuchi, Kenji Uchiyama, Hideaki Hisamoto, Manabu Tokeshi, Takehiko Kitamori
    Lab on a Chip, 2, 4, 188, 192, Royal Society of Chemistry, 2002年11月01日, [査読有り]
    英語, 研究論文(学術雑誌), An integrated multireactor system for 2 × 2 parallel organic synthesis has been developed on a single glass microchip. Three-dimensional channel circuits in the chip were fabricated by laminating three glass plate layers. The fabrication method is a straightforward extension of the conventional one, and topological equivalence for any three-dimensional circuits can be constructed easily with it. 2 × 2 phase-transfer amide formation reactions, which constitute a simple model for combinatorial synthesis, were successfully carried out on the microchip, and the integrity of the three-dimensional circuits was confirmed. Combinatorial chemistry with multi-microreactors, in conjunction with a high-throughput screening method based on μ-TAS technologies, is expected to provide an efficient tool for drug discovery.
  • 分析システムの集積化(30) マルチチャネルマイクロチップを用いたマイクロELISAシステムの開発               
    山中 麻帆, 佐藤 記一, 森島 圭祐, 渡慶次 学, 木村 博子, 北森 武彦
    日本分析化学会講演要旨集, 51年会, 235, 235, (公社)日本分析化学会, 2002年09月
    日本語
  • Stabilization of liquid interface and control of two-phase confluence and separation in glass microchips by utilizing octadecylsilane modification of microchannels
    A Hibara, M Nonaka, H Hisamoto, K Uchiyama, Y Kikutani, M Tokeshi, T Kitamori
    ANALYTICAL CHEMISTRY, 74, 7, 1724, 1728, AMER CHEMICAL SOC, 2002年04月, [査読有り]
    英語, 研究論文(学術雑誌), We demonstrated a liquid/liquid and a gas/liquid two-phase crossing flow in glass microchips. A 250-mum-wide microchannel for aqueous-phase flow was fabricated on a top glass plate. Then, as a way to utilize the surface energy difference for stable phase confluence and separation, a 250-mum-wide microchannel for organic-phase (or gas-phase) flow was fabricated on a bottom glass plate and the wall was chemically modified by octadecylsilane (ODS) group. The top and bottom plates were sealed only by pressure. A microchannel pattern was designed so that the two phases made contact at the crossing point of the straight microchannels. The crossing point was observed with an optical microscope. Results showed that the ODS modification of the microchannel wall clearly improved stability of the interface between the two fluids. Pressure difference between fluids was measured and the interface of water and nitrobenzene was stable for the pressure difference from +300 Pa to -200 Pa. The pressure drop in a countercurrent flow configuration was also estimated, and the pressure difference required to realize the countercurrent flow was less than the allowable pressure range. Finally, we discussed the advantages of utilizing this approach.
  • Single-cell analysis by a scanning thermal lens microscope with a microchip: Direct monitoring of cytochrome c distribution during apoptosis process
    E Tamaki, K Sato, M Tokeshi, K Sato, M Aihara, T Kitamori
    ANALYTICAL CHEMISTRY, 74, 7, 1560, 1564, AMER CHEMICAL SOC, 2002年04月, [査読有り]
    英語, 研究論文(学術雑誌), We developed a microsystem for cell experiments consisting of a scanning thermal lens microscope detection system and a cell culture microchip. The microchip system was good for liquid control in microspace, and this results in secure cell stimulation and coincident in vivo observation of the cell responses. The system could detect nonfluorescent biological substances with extremely high sensitivity without any labeling materials and had a high spatial resolution of similar to1 mum. This system was applied to monitoring of cytochrome c distribution in a neuroblastoma-glioma hybrid cell cultured in the microflask (1 mm x 10 mm x 0.1 mm; 1 muL) fabricated in a glass microchip. Cytochrome c release from mitochondria to cytosol during the apoptosis process was successfully monitored with this system. The cytochrome c detected with this system was estimated to be mu10 zmol. We concluded that the system was suitable for measuring the distribution of chemical substances in a single cell because the microchip is good for liquid handling in microspace and the thermal lens microscope has high sensitivity and spatial resolution.
  • Continuous-flow chemical processing on a microchip by combining microunit operations and a multiphase flow network
    M Tokeshi, T Minagawa, K Uchiyama, A Hibara, K Sato, H Hisamoto, T Kitamori
    ANALYTICAL CHEMISTRY, 74, 7, 1565, 1571, AMER CHEMICAL SOC, 2002年04月, [査読有り]
    英語, 研究論文(学術雑誌), A new design and construction methodology for integration of complicated chemical processing on a microchip was proposed. This methodology, continuous-flow chemical processing (CFCP), is based on a combination of microunit operations (MUOs) and a multiphase flow network. Chemical operations in microchannels, such as mixing, reaction, and extraction, were classified into several MUOs. The complete procedure for Co(II) wet analysis, including a chelating reaction, solvent extraction, and purification was decomposed into MUOs and reconstructed as CFCP on a microchip. Chemical reaction and molecular transport were realized in and between continuous liquid flows in a multiphase flow network, such as aqueous/aqueous, aqueous/organic, and aqueous/organic/aqueous flows. When the determination of Co(H) in an admixture of Cu(II) was carried out using this methodology, the determination limit (2sigma) was obtained as 18 nM, and the absolute amount of Co chelates detected was 0.13 zmol, that is, 78 chelates. The sample analysis time was faster than that of a conventional processing system. Moreover, troublesome operations such as phase separation and acid and alkali washing, all necessary for the conventional system, were simplified. The CFCP methodology proposed here can be applied to various on-chip applications.
  • Microchip-based immunoassay system with branching multichannels for simultaneous determination of interferon-gamma
    K Sato, M Yamanaka, H Takahashi, M Tokeshi, H Kimura, T Kitamori
    ELECTROPHORESIS, 23, 5, 734, 739, WILEY-V C H VERLAG GMBH, 2002年03月, [査読有り]
    英語, 研究論文(学術雑誌), A bead-bed immunoassay system suitable for simultaneous assay of multiple samples was constructed on a microchip. The chip had branching multichannels and four reaction and detection regions; the constructed system could process four samples at a time with only one pump unit. Interferon gamma was assayed by a 3-step sandwich immunoassay with the system coupled to a thermal lens microscope as a detector. The biases of the signal intensities obtained from each channel were within 10%, and coefficients of variation were almost the same level as the single straight channel assay. The assay time for four samples was 50 min instead of 35 min for one sample in the single-channel assay; hence higher throughput was realized with the branching structure chip.
  • Pile-up glass microreactor
    Y Kikutani, A Hibara, K Uchiyama, H Hisamoto, M Tokeshi, T Kitamori
    LAB ON A CHIP, 2, 4, 193, 196, ROYAL SOC CHEMISTRY, 2002年, [査読有り]
    英語, 研究論文(学術雑誌), We made a 'pile-up' microreactor in which ten levels of microchannel circuits were integrated to form a single glass entity. Solutions were distributed to each layer via cylindrical holes with a diameter much larger than that of the microchannel. Fabrication of the pile-up reactor was completed using only conventional photolithography, wet etching and thermal bonding techniques, and no special facilities or instruments were required. An amide formation reaction between amine in aqueous solution and acid chloride in organic solution was carried out using the pile-up reactor. The yield of the amide formation reaction is dependent on the size of the specific surface area between the two solutions, and the small space inside the microchannels is good for acquiring a large specific surface area without any stirring processes. The maximum throughput for the ten-layered pile-up reactor was ten times larger than that of a single-layered one, yet the reaction yield was still high. Productivity of the pile-up reactor for the reaction was as high as on a gram per hour scale. This value suggests that many conventional plants producing fine chemicals can be replaced by microreactors through the numbering- up technology.
  • Integration of photo-thermal spectroscopy detection system on a chip
    A Hattori, J Yamaguchi, M Tokeshi, T Kitamori
    BIOMEDICAL NANOTECHNOLOGY ARCHITECTURES AND APPLICATIONS, 4626, 352, 356, SPIE-INT SOC OPTICAL ENGINEERING, 2002年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), Miniaturization of sensitive detection system is a key factor for integrated chemical systems. Thermal lens microscope can be applied to the ultra-sensitive detection of non-fluorescent molecules in many applications. By using a very small SELFOC(TM) micro lens as an objective, palmtop-sized thermal lens microscope (PTLM) has been constructed. A calibration curve for an aqueous solution in a range of 1.0 x 10(-7)-5.0 x 10(-6) mol/L has been measured in this newly designed PTLM.
  • Fast and high conversion phase-transfer synthesis exploiting the liquid-liquid interface formed in a microchannel chip
    H Hisamoto, T Saito, M Tokeshi, A Hibara, T Kitamori
    CHEMICAL COMMUNICATIONS, 24, 2662, 2663, ROYAL SOC CHEMISTRY, 2001年12月, [査読有り]
    英語, 研究論文(学術雑誌), The large specific interfacial areas and short molecular diffusion distances provided by glass microchips play important roles not only for effective phase-transfer synthetic reaction, but also for avoiding an undesirable side reaction.
  • On-chip integration of sequential ion-sensing system based on intermittent reagent pumping and formation of two-layer flow
    H Hisamoto, T Horiuchi, K Uchiyama, M Tokeshi, A Hibara, T Kitamori
    ANALYTICAL CHEMISTRY, 73, 22, 5551, 5556, AMER CHEMICAL SOC, 2001年11月, [査読有り]
    英語, 研究論文(学術雑誌), A sequential ion-sensing system using a single microchip was successfully realized. The system developed here involves intermittent pumping of plural organic phases into a microchannel, followed by contact with a single aqueous phase to form a stable organic-aqueous two-layer flow inside the microchannel. Because the plural organic phases created by intermittent flow contain the same lipophilic pH indicator dye but different ion-selective neutral ionophores, different ions can be sequentially and selectively extracted into the different organic phases, where they can be determined by thermal lens microscopy (TLM). We used KD-A3 as the lipophilic pH indicator dye and valinomycin and DD16C5 as neutral ionophores to demonstrate sequential ion sensing of potassium and sodium ions by measuring the deprotonated dye caused by the ion extraction. The integrated microfluidic system proposed here allows multi-ion sensing, which is not easily demonstrated by conventional ion sensor technology using a solvent polymeric membrane. The minimum volume of single organic phase needed to obtain an equilibrium response without dilution by cross dispersion of two organic phases was ca. 500 nL in our system, indicating that the required amounts of expensive reagents in one measurement could be reduced to 1.7 ng and 2.8 ng for the dye and ionophore molecules, respectively.
  • Integration of a wet analysis system on a glass chip: Determination of Co(II) as 2-nitroso-1-naphthol chelates by solvent extraction and thermal lens microscopy
    Tomoko Minagawa, Manabu Tokeshi, Takehiko Kitamori
    Lab on a Chip, 1, 1, 72, 75, Royal Society of Chemistry, 2001年09月01日, [査読有り]
    英語, 研究論文(学術雑誌), The integration of a wet analysis system on a glass chip was demonstrated and determination of Co(II) was performed using this system. The Co(II) was extracted into m-xylene from aqueous solution as 2-nitroso-1-naphthol chelates, and colorimetric determination of the: m-xylene phase was applied by a thermal lens microscope. The integration of the chemical operation procedures shown here leads to a considerable reduction in analyzing time. The time for extraction in the integrated system, 10 min, was about tenfold shorter than a conventional system using a separatory funnel and mechanical shaker. Moreover, troublesome operations such as phase separation necessary for the conventional system could be omitted. The determination of Co(II) in the range 2 × 10-7-1 × 10-8 M, which was estimated to be 0.072-1.44 zmol, was achieved.
  • Micro-chip capillary electrophresis - Frontier of m-TAS 2. Integration of combined chemical processes onto microchips
    A Hibara, M Tokeshi, T Kitamori
    ELECTROCHEMISTRY, 69, 8, 620, 623, ELECTROCHEMICAL SOC JAPAN, 2001年08月, [査読有り]
    日本語, 研究論文(学術雑誌)
  • Photothermal temperature control of a chemical reaction on a microchip using an infrared diode laser
    MN Slyadnev, Y Tanaka, M Tokeshi, T Kitamori
    ANALYTICAL CHEMISTRY, 73, 16, 4037, 4044, AMER CHEMICAL SOC, 2001年08月, [査読有り]
    英語, 研究論文(学術雑誌), We have demonstrated that a miniaturized device with IR laser heating of the solvents based on a photothermal effect, is capable of fast and localized control of an enzymatic reaction on a microchip under flow conditions. Using noncontact spectroscopic temperature-sensing techniques, we measured temperature dynamics and spatial distribution and compared the measurements with results of numerical simulation analysis. The device was operated at ultrafast heating and cooling rates of 67 and 53 degreesC/s, respectively, which is 30 times faster than conventional systems and 3-6 times faster than electrothermal miniaturized thermocyclers. The IR laser-mediated heater is characterized by a significantly reduced heated volume of only 5 nL, compared to existing chip-based systems with electrothermal heating. Direct heating of a sample with extremely small heat capacity led us to a fast heating rate, and efficient heat removal through heat transfer to the glass substrate resulted in a fast cooling rate. Reproducible temperature levels with dwell times shorter than 0.5 s were achieved. The enzyme reaction on a chip was successfully controlled with 0.6-s time resolution, using periodic photothermal heating by IR laser. The IR diode laser is compact and thus suits well the miniaturized system design. Our work gives the basis for integration in a chip format of a variety of chemical processes that require fast temperature control.
  • Thermal lens microscope for integrated chemistry laboratory on glass microchips
    A Hibara, K Sato, H Hisamoto, K Uchiyama, MN Slyadnev, M Tokeshi, T Kitamori
    PROGRESS IN NATURAL SCIENCE, 11, S237, S241, TAYLOR & FRANCIS LTD, 2001年05月, [査読有り]
    英語, 研究論文(学術雑誌), Thermal lens microscope (TLM) can be a powerful tool for a detection method for integrated chemistry laboratory (ICL). In spite of great potential of ICL, its application has been restricted due to the lack of highly applicable and sensitive detection methods. TLM developed by our group meets requirements of detection method for ICL, such as high sensitivity, high spatial resolution, and wide applicability. In this review, the principle and characteristics of TLM are introduced and usefulness of TLM in ICL is demonstrated in some analytical applications.
  • Determination of subyoctomole amounts of nonfluorescent molecules using a thermal lens microscope: Subsingle molecule determination
    M Tokeshi, M Uchida, A Hibara, T Sawada, T Kitamori
    ANALYTICAL CHEMISTRY, 73, 9, 2112, 2116, AMER CHEMICAL SOC, 2001年05月, [査読有り]
    英語, 研究論文(学術雑誌), The photothermal effect of an ultratrace amount of non fluorescent molecules in liquid was determined optimizing the optical arrangement for a thermal lens microscope, The optimized experimental setup could be determined from the evaluation of probing volume and the concentration of the sample solutions even when the expectation of the molecule number in the probing region was less than a single molecule. The minimum expectation, which is explained as being the time average, was 0.4 molecule of Pb(II) octaethylporphyrin (OEP) In benzene. The concentrations in the 9.7 x 10(-11)-7.8 x 10(-10) M region used in this work corresponded to the expected number of 0.4 -3.4 molecules, and the calibration curve in this region showed good linearity. Taking into account the enhancement factor of solvent, the molar absorption coefficient of solute, and the optimization of the optical arrangement, the present result, which was the determination limit of 0.34, was consistent with that previously reported. The relation between molecular behavior in the probing volume and the signal was discussed, The average temperature rise in the probing volume by the photothermal effect for the single OEP molecule was estimated as 3.1 muK and this value nas detectable, based on conventional thermal lens measurements for bulk scale sample.
  • Morphological dependence of radiative and nonradiative relaxation energy balance in photoexcited aryl ether dendrimers as observed by fluorescent and thermal lens spectroscopies
    Y Wakabayashi, M Tokeshi, A Hibara, DL Jiang, T Aida, T Kitamori
    JOURNAL OF PHYSICAL CHEMISTRY B, 105, 19, 4441, 4445, AMER CHEMICAL SOC, 2001年05月, [査読有り]
    英語, 研究論文(学術雑誌), Radiative and nonradiative relaxation processes after excitation by ultraviolet light were measured for o-, m-, and p-aryl ether dendrimers of fourth generation (o-, m-, and p-Ar(L4)(2)) by using fluorescent and thermal lens spectroscopies. Samples were dissolved in CH2Cl2 to provide concentrations of a constant absorbance at excitation light wavelength (244 nm). Regarding the nonradiative process, we investigated thermal lens signal dependence on the light modulation frequency to determine the nonradiative relaxation rate. When frequency ranged from 4 to 200 Hz, the thermal lens signal became larger in the order p-, o-, m-Ar(L4)(2), while the fluorescent intensity became larger in the order p-, m-, o-Ar(L4)2. We transformed these results into an energy balance of the radiative and nonradiative relaxation processes. Our analysis showed that 50% of the excitation energy was not released from p-Ar(L4)2 for a 100-ms order. Next, the measured fluorescence decay times of the three Ar(L4)2 were obtained as 1.7 ns which revealed that the anomalous properties of dendrimers did not originate in long-lived electronic excitation states, but in long-term storage of internal energy. To explain this phenomenon, a novel mechanism for intramolecular energy storage with nonergodic energy transfer should be considered. Last, we proposed that the nonlinear conjugated oscillator model of Fermi-Pasta-Ulam theory would be suitable for the intramolecular energy storage.
  • On-chip integration of neutral ionophore-based ion pair extraction reaction
    H Hisamoto, T Horiuchi, M Tokeshi, A Hibara, T Kitamori
    ANALYTICAL CHEMISTRY, 73, 6, 1382, 1386, AMER CHEMICAL SOC, 2001年03月, [査読有り]
    英語, 研究論文(学術雑誌), Integration of a neutral ionophore-based ion pair extraction reaction onto a glass microchip was performed. Since the Liquid microspace provides a short molecular diffusion distance and a large specific interfacial area of the liquid-liquid interface, novel attractive analytical features arise such as extremely fast ion sensing and ultrasmall reagent solution volume. In contrast to the slow response time of a standard ion optode, in which the response time is basically governed by slow diffusion of ionic species in the viscous polymer membrane, that of the on-chip ion-sensing system is clearly faster due to the short molecular diffusion distance and low viscosity of organic solution. In this case, the organic solution containing a neutral ionophore and a lipophilic pH indicator dye and the aqueous solution containing sample ion were independently introduced into microchannel to form an organic-aqueous interface. Then determination of the ion was performed by thermal lens microscopy at the downstream of the organic phase under continuous-now conditions. The response time and minimum required reagent solution volume of the on-chip ion-sensing system are about 8 s and 125 nL, respectively, indicating the advantages of using the liquid microspace. Other advantages of the on-chip ion pair extraction system arising from using the liquid microspace and microfluidic system are also discussed in detail.
  • Determination of carcinoembryonic antigen in human sera by integrated bead bed immunoasay in a microchip for cancer diagnosis
    K Sato, M Tokeshi, H Kimura, T Kitamori
    ANALYTICAL CHEMISTRY, 73, 6, 1213, 1218, AMER CHEMICAL SOC, 2001年03月, [査読有り]
    英語, 研究論文(学術雑誌), A bead-bed immunoassay system was structured on a microchip and applied to determine carcinoembryonic antigen (CEA), which is a commonly used marker of colon cancer. Polystyrene beads precoated with anti-CEA antibody were introduced into a microchannel, and then a serum sample containing CEA, the first antibody, and the second antibody conjugated with colloidal gold were reacted successively, The resulting antigen-antibodies complex, fixed on the bead surface, was detected using a thermal lens microscope (TLM). A highly elective and sensitive determination of an ultratrace amount of CEA in human sera was made possible by a sandwich immunoassay system that needs three antibodies for an assay. A detection limit dozens of times lower than the conventional ELISA was achieved. Moreover, when serum samples for 13 patients were assayed with this system, there was a high correlation (r = 0.917) with the conventional ELISA. The integration reduced the time necessary for the antigen-antibody reaction to similar to1%, thus shortening the overall analysis time from 45 h to 35 min. Moreover, troublesome operations required for conventional heterogeneous immunoassays could be much simplified. This microchip-based diagnosis system is the first microchip-based system that is practically useful for clinical diagnoses with short analysis time, high sensitivity, and easy procedures.
  • Development of high performance immunoassay system using multichannel microchip
    M. Yamanaka, K. Sato, M. Tokeshi, H. Katou, H. Kimura, T. Kitamori
    2001 International Microprocesses and Nanotechnology Conference, MNC 2001, 26, 27, Institute of Electrical and Electronics Engineers Inc., 2001年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), Immunoassay is known as one of the most important analytical methods and widely used in clinical diagnoses and biochemical studies. The conventional immunoassay, however, requires a long assay time. We developed a bead-bed immunoassay system integrated on a microchip which successfully reduces the assay time from 2 days to 30 minutes using simple operations for assay (Sato et al, 2000 and 2001). Here, aiming at high throughput assay, an integrated immunoassay system using a multichannel microchip was developed for simultaneous analyses of multiple samples.
  • Integrating combinatorial synthesis on a single glass microchip
    Y. Kikutani, T. Horiuchi, H. Hisamoto, K. Uchiyama, M. Tokeshi, T. Kitamori
    2001 International Microprocesses and Nanotechnology Conference, MNC 2001, 18, Institute of Electrical and Electronics Engineers Inc., 2001年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), Summary form only given. Combinatorial chemistry is becoming prevalent methodology in preparing samples for high-throughput drug screening. Here we report a prototype of a combinatorial synthetic system integrated on a single glass microchip. By sandwiching a glass plate having pierced holes between two channel-etched glass surfaces, we made a glass chip in which channels in upper and bottom plates can cross without contacting each other (two-level crossing). To check the 3-D channel network, combinatorial amide syntheses by mixing two acid chlorides with two amines were carried out.
  • DNA melting analysis on a microchip after PCR amplification
    M. N. Slyadnev, K. Sato, M. Tokeshi, T. Kitamori
    2001 International Microprocesses and Nanotechnology Conference, MNC 2001, 194, Institute of Electrical and Electronics Engineers Inc., 2001年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), DNA melting analysis requires precise temperature measurement. Since heat capacity of the sample inside microchip is extremely small, a measurement device can affect temperature response. In this paper we report a method of temperature monitoring that was implemented on a chip to overcome this difficulties.
  • Acceleration of an enzymatic reaction in a microchip
    Yuki Tanaka, Maxim N. Slyadnev, Kiichi Sato, Manabu Tokeshi, Haeng-Boo Kim, Takehiko Kitamori
    Analytical Sciences, 17, 7, 809, 810, 2001年, [査読有り]
    英語, 研究論文(学術雑誌)
  • Integration of a wet analysis system on a glass chip: determination of Co(II) as 2-nitroso-1-naphthol chelates by solvent extraction and thermal lens microscopy
    T Minagawa, M Tokeshi, T Kitamori
    LAB ON A CHIP, 1, 1, 72, 75, ROYAL SOC CHEMISTRY, 2001年, [査読有り]
    英語, 研究論文(学術雑誌), The integration of a wet analysis system on a glass chip was demonstrated and determination of Co(II) was performed using this system. The Co(II) was extracted into m-xylene from aqueous solution as 2-nitroso-1-naphthol chelates, and colorimetric determination of the m-xylene phase was applied by a thermal lens microscope. The integration of the chemical operation procedures shown here leads to a considerable reduction in analyzing time. The time for extraction in the integrated system, 10 min, was about tenfold shorter than a conventional system using a separatory funnel and mechanical shaker. Moreover, troublesome operations such as phase separation necessary for the conventional system could be omitted. The determination of Co(II) in the range 2 x 10(-7)-1 x 10(-8) M, which was estimated to be 0.072-1.44 zmol, was achieved.
  • Inner-channel preparation of polymer membrane by interfacial polycondensation
    Y Shimizu, H Hisamoto, A Hibara, M Tokeshi, T Kitamori
    MICROPROCESSES AND NANOTECHNOLOGY 2001, DIGEST OF PAPERS, 20, 21, JAPAN SOCIETY APPLIED PHYSICS, 2001年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス)
  • Optimization of the optical-scheme design for photothermal-lens microscopy in microchips
    MA Proskurnin, M Tokeshi, MN Slyadnev, T Kitamori
    ANALYTICAL SCIENCES, 17, S454, S457, JAPAN SOC ANALYTICAL CHEMISTRY, 2001年, [査読有り]
    英語, 研究論文(学術雑誌), The optical-scheme design for a thermal lens microscope was optimized for the measurements in a microchannel. The actual pathlength, irradiated volume, and the diameter of the thermal lens were estimated The experimental data are in good agreement with the theoretically calculations. The noise sources (laser noises, instrumental flicker noise, convection, and flow noise) were studied, and the possible effects of probe laser on transient and steady-state thermal lens measurements were estimated. The limit of detection of ferroin at 488.0 nm is 1x10(-8) mol dm(-3) (3x10(-21) mol in the detection volume). The linear calibration range is nx 10(-8) - n x 10(-4) mol dm(-3), the repeatability RSD for this range is 3-7%.
  • Infrared absorption characteristics of large-sized spherical aryl-ether dendrimers
    Y Wakabayashi, M Tokeshi, A Hibara, DL Jiang, T Aida, T Kitamori
    ANALYTICAL SCIENCES, 16, 12, 1323, 1326, JAPAN SOC ANALYTICAL CHEMISTRY, 2000年12月, [査読有り]
    英語, 研究論文(学術雑誌), A specially designed experimental setup including a newly constructed KBr cell, a light source, a monochromator and an IR detection system suitable for strictly calibrated IR absorption measurements was constructed in order to elucidate strange phenomenon associated with cis-trans photo-isomerization at 6.26 mum of the azobenzene core located at the center of an aryl-ether dendrimer (L5AZO). The setup used an ordinary Nichrome source to measure the photon flux, irradiation area, and photon absorption rate as exactly as possible. The photon absorption rate was obtained as 1.2 x 10(-3) photons/s molecule and the absorption cross section of L5AZO molecules was estimated to be 3.1 x 10(-19) cm(2)/molecule. Since these values of the absorption rate and absorption cross section are not abnormal, the occurrence of a simultaneous five-photon absorption is almost impossible. Therefore, the five-photon absorption and photo-isomerization shown by L5AZO suggested that the multiphoton process was not simultaneous absorption, but possibly a sequential absorption and energy storage until the equivalent energy of isomerization was reached.
  • Non-contact photothermal control of enzyme reactions on a microchip by using a compact diode laser
    Y Tanaka, MN Slyadnev, A Hibara, M Tokeshi, T Kitamori
    JOURNAL OF CHROMATOGRAPHY A, 894, 1-2, 45, 51, ELSEVIER SCIENCE BV, 2000年10月, [査読有り]
    英語, 研究論文(学術雑誌), Photothermal temperature control of an enzyme-catalyzed reaction in a microchip using a diode laser was demonstrated. A laser beam with energy of 10 mW was used to irradiate an absorbing target placed on top of the microchip cover plate. Theoretical calculations have shown that temperature in the microchannel can be locally increased by 5-7 degrees C during short time intervals, due to heat released by the target. The rate of the enzyme reaction, which was initially inhibited due to cooling of the chip to low temperature, was increased when the target was irradiated. The products were detected by a thermal lens microscope. The product concentration was shown to depend on irradiation time, laser intensity and substrate concentration. Reaction characteristics (rate constant of the reaction) were then derived from these dependencies. The reaction volume and absolute quantity of the reaction product were estimated as 10 nl and 100 fmol, respectively. It was also demonstrated that a direct solvent heating method using infrared radiation could control the reaction in the microchannel. (C) 2000 Elsevier Science B.V. All rights reserved.
  • Integration of a microextraction system - Solvent extraction of a Co-2-nitroso-5-dimethylaminophenol complex on a microchip
    M Tokeshi, T Minagawa, T Kitamori
    JOURNAL OF CHROMATOGRAPHY A, 894, 1-2, 19, 23, ELSEVIER SCIENCE BV, 2000年10月, [査読有り]
    英語, 研究論文(学術雑誌), A newly designed microchannel for solvent extraction was fabricated in a quartz glass chip and applied to solvent extraction of a Co-2-nitroso-5-dimethylaminophenol complex. The aqueous solution of Co complex and toluene were introduced into the microchannel, and the Co complex extracted in toluene was detected by thermal lens microscopy (TLM). The Co complex was quickly extracted into toluene when the flow was stopped. The observed extraction time, ca. 50 s, was almost equivalent to the value calculated using the diffusion distance and diffusion coefficient. The dependence of the TLM signal on the concentration of the Co complex showed good linearity in the range of 1.10(-7)-1.10(-6) M. (C) 2000 Elsevier Science B.V. All rights reserved.
  • 熱レンズ顕微鏡による非蛍光性単一分子計測
    佐藤 記一, 渡慶次 学, 火原 彰秀, 北森 武彦
    生物物理, 40, 4, 262, 265, 一般社団法人日本生物物理学会, 2000年07月25日
    日本語
  • Molecular transport between two phases in a microchannel
    K Sato, M Tokeshi, T Sawada, T Kitamori
    ANALYTICAL SCIENCES, 16, 5, 455, 456, JAPAN SOC ANALYTICAL CHEM, 2000年05月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Integration of a microextraction system on a glass chip: Ion-pair solvent extraction of Fe(II) with 4,7-diphenyl-1,10-phenanthrolinedisulfonic acid and tri-n-octylmethylammonium chloride
    M Tokeshi, T Minagawa, T Kitamori
    ANALYTICAL CHEMISTRY, 72, 7, 1711, 1714, AMER CHEMICAL SOC, 2000年04月, [査読有り]
    英語, 研究論文(学術雑誌), An ion-pair solvent extraction was performed in a microchannel fabricated in a quartz glass chip. The aqueous solution of Fe-bathophenanthrolinedisulfonic acid complex and the chloroform solution of tri-n-octylmethyl-ammonium chloride were introduced into the microchannel, and a parallel two-phase laminar now was formed. The ion-pair product extracted in chloroform was monitored by the thermal lens microscope. The ion-pair product was gradually extracted from aqueous solution into chloroform when the flow was very slow or stopped, while nothing was extracted into chloroform when the flow was fast. The time for extraction in the present 250 mu m microchannel, 45 s, roughly coincided with the molecular diffusion time, and the extraction time was at least 1 order shorter compared with the ordinary extraction time using a separatory funnel and mechanical shaking. The micro-space in the microchannel was characterized by the large specific interface area and short diffusion distance, and these characteristics may contribute to highly efficient extraction without mechanical shaking. The success of this molecular transport may lead to the integration of more complicated separation and chemical operations on a microchip and more applications.
  • Integration of an immunosorbent assay system: Analysis of secretory human immunoglobulin A on polystyrene beads in a microchip
    Kiichi Sato, Manabu Tokeshi, Tamao Odake, Hiroko Kimura, Takeshi Ooi, Masayuki Nakao, Takehiko Kitamori
    Analytical Chemistry, 72, 6, 1144, 1147, 2000年03月15日, [査読有り]
    英語, 研究論文(学術雑誌), An immunosorbent assay system was integrated into a glass microchip. Polystyrene beads were introduced into a microchannel, and then hutnan secretory immunoglobulin A (s-IgA) adsorbed on the bead surface was reacted with colloidal gold conjugated anti-s-IgA antibody and detected by a thermal lens microscope. The scale merits of liquid microspace on the molecular behavior remarkably contributed to reduced assay time. The integration cut the time necessary for the antigen-antibody reaction by 1/90, thus shortening the overall analysis time from 24 h to less than 1 h. Moreover, troublesome operations required for conventional immunosorbent assays could be replaced by simple operations.
  • Integrated micro chemical lab: Detection of biomolecules and expectation to electrochemistry
    M Tokeshi, T Kitamori
    ELECTROCHEMISTRY, 68, 3, 192, 196, ELECTROCHEMICAL SOC JAPAN, 2000年03月, [査読有り]
    日本語, 研究論文(学術雑誌)
  • イムノアッセイシステムのマイクロチップヘの集積化
    佐藤 記一, 渡慶 次学, 木村 博子, 北森 武彦
    生物物理化学, 44, 2, 73, 77, Japanese Electrophoresis Society, 2000年
    日本語, イムノアッセイシステムをガラスマイクロチップ内に集積化した. チップの微細流路内に導入したポリスチレンビーズ表面に分泌型免疫グロブリンAを吸着させ, 金コロイド標識した抗体を反応させた後, 生じた複合体量を熱レンズ顕微鏡で測定した. 集積化により反応が従来法の90分の1の時間で終了したため, 合計の分析時間が24時間から45分程度へと短縮できた. 微小空間のスケールメリットによって反応が効率よく起こり, 時間の短縮につながったものと思われる. さらに従来法で必要であった煩雑な操作が簡便な操作に置き換えられ, 操作性も向上した. 作製した集積化イムノアッセイシステムは医療診断や生化学研究において有効な分析手法であると思われる.
  • Integrated Chemistry -The Present Situation of Integration of Chemical System-
    Manabu Tokeshi, Takehiko Kitamori
    Yosetsu Gakkai Shi/Journal of the Japan Welding Society, 69, 6, 514, 516, 2000年, [査読有り]
    英語, 研究論文(学術雑誌)
  • Integration of flow injection analysis and zeptomole-level detection of the Fe(II)-o-phenanthroline complex
    K Sato, M Tokeshi, T Kitamori, T Sawada
    ANALYTICAL SCIENCES, 15, 7, 641, 645, JAPAN SOC ANALYTICAL CHEM, 1999年07月, [査読有り]
    英語, 研究論文(学術雑誌), Microchannels having a 150x100 mu m cross section were fabricated in a quartz glass chip as a component in an integrated flow injection analysis (FIA) system. They were put to use for flow, mixing, reaction, and detection. The reaction system was a chelating reaction of divalent iron ion with o-phenanthroline (o-phen), and a photothermal microscope was applied for the ultra-sensitive detection of the non-fluorescent reaction product. Nano liter levels of solutions were introduced and transported by capillary action and mixed by molecular diffusion. Zeptomole levels of the reaction product were detected quantitatively. This was the first demonstration of an on-chip chemical determination device which integrates the primitive FIA system without using electroosmotic liquid control or fluorometric determination.
  • Sub-zeptomole detection in a microfabricated glass channel by thermal-lens microscopy
    K Sato, H Kawanishi, M Tokeshi, T Kitamori, T Sawada
    ANALYTICAL SCIENCES, 15, 6, 525, 529, JAPAN SOC ANALYTICAL CHEM, 1999年06月, [査読有り]
    英語, 研究論文(学術雑誌), A thermal-lens microscope which we developed was applied to an ultramicro quantity determination of a dye in an aqueous solution filling a microchannel (150 mu m wide and 100 mu m deep) fabricated in a quartz glass substrate. The detection volume, which corresponded to the confocal volume, was estimated to be 1.3 fl. The detection limit of the dye molecules was 160 ymol, and the calibration line showed good linearity in the sub-zmol-to-zmol region. This detection sensitivity is equivalent to that of laser-induced fluorometry. The thermal-lens signal measured in the microchannel was more stable than that measured in a liquid micro space between a slide glass and a cover glass, which was much wider than the microchannel. This may have been due to a suppression of convection in the microchannel. The thermal lens method can be applied to non-fluorescent chemical species, and is thus very suitable detection method for integrated chemistry systems.
  • Single- And countable-molecule detection of non-fluorescent molecules in liquid phase
    Manabu Tokeshi, Marika Uchida, Kenji Uchiyama, Tsuguo Sawada, Takehiko Kitamori
    Journal of Luminescence, 83-84, 261, 264, Elsevier, 1999年, [査読有り]
    英語, 研究論文(学術雑誌), A thermal lens microscope was applied to ultrasensitive detection of non-fluorescent molecule in liquid. The calibration curve showed good linearity in the 5.4-27 molecules region. The minimum number of molecules detected was 5.4 and the detection limit of Pb(II) octaethylporphyrin in benzene was 0.5 molecules. Our thermal lens microscope is a powerful tool for ultrasensitive detection of non-fluorescent molecules at the single-molecule level and offers a great potential for further applications. © 1999 Elsevier Science B.V. All rights reserved.
  • Long-term energy storage of dendrimers
    Yuki Wakabayashi, Manabu Tokeshi, Dong-Ling Jiang, Takuzo Aida, Takehiko Kitamori
    Journal of Luminescence, 83-84, 313, 315, Elsevier, 1999年, [査読有り]
    英語, 研究論文(学術雑誌), We have recently reported the anomalous cis-trans isomerization, which induced by 5-photon absorption (5-PA) of a spherical azo-dendrimer (L5AZO) by IR radiation from a nichrom source. In this study, we measured absolute absorption of L5AZO using a calibrated detector in order to investigate these anomalous phenomena. The number of infrared photons absorbed by a L5AZO was estimated as only 10-3 (photons s-1). This result suggests that L5AZO absorbs five photons not simultaneously but sequentially, and suggests the possibility of long-term intramolecular energy storage is anticipated. © 1999 Elsevier Science B.V. All rights reserved.

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    野呂田楓, 野呂田楓, 野呂田楓, 石塚宣, 廣瀬みさ, 真栄城正寿, 渡慶次学, 原島秀吉, 山田勇磨, 日本DDS学会学術集会プログラム予稿集, 39th, 2023年
  • 癌光治療用ミトコンドリア標的型ナノカプセルの殺細胞効果向上を目指した試み
    長縄莉奈, 高野勇太, 高野勇太, 趙韓俊, 真栄城正寿, 渡慶次学, 原島秀吉, 山田勇磨, 日本DDS学会学術集会プログラム予稿集, 39th, 2023年
  • セルロースナノファイバシートによる単一細胞外小胞解析
    川口彰太, 安井隆雄, 安井隆雄, 安井隆雄, 嶋田泰佑, 神谷由紀子, 浅沼浩之, 真栄城正寿, 渡慶次学, 古賀大尚, 村上正晃, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム学会研究会講演要旨集(CD-ROM), 47th, 2023年
  • セルロースナノファイバー紙の乾燥収縮を利用した単一細胞外小胞解析
    川口彰太, 安井隆雄, 安井隆雄, 安井隆雄, 嶋田泰佑, 神谷由紀子, 浅沼浩之, 真栄城正寿, 渡慶次学, 古賀大尚, 村上正晃, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会春季年会講演予稿集(Web), 103rd, 2023年
  • 酵素と基質をセルロース媒体に固定化した電気化学ATP-乳酸センサー
    九鬼静香, 石田晃彦, 真栄城正寿, 谷博文, 渡慶次学, 化学系学協会北海道支部冬季研究発表会(Web), 2022, 2022年
  • ルシフェラーゼ発現大腸菌の紙デバイス上での発現誘導
    古坐あすか, 石田晃彦, 真栄城正寿, 谷博文, 渡慶次学, 化学系学協会北海道支部冬季研究発表会(Web), 2022, 2022年
  • 抗SARS-CoV-2抗体およびSARS-CoV-2スパイクタンパク質断片の非競合蛍光偏光免疫分析法
    高橋和希, 福山真央, 粕谷素洋, 真栄城正寿, 石田晃彦, 谷博文, 重村幸治, 火原彰秀, 渡慶次学, 化学系学協会北海道支部冬季研究発表会(Web), 2022, 2022年
  • 薬剤送達ナノ粒子作製用ガラス製マイクロ流体システムの開発
    岡田悠斗, 真栄城正寿, 真栄城正寿, 佐藤悠介, 石田晃彦, 谷博文, 原島秀吉, 渡慶次学, 化学系学協会北海道支部冬季研究発表会(Web), 2022, 2022年
  • タンパク質分析用ペーパー分析デバイスの開発を目的としたろ紙上でのホタルルシフェラーゼ活性の制御
    野中康伸, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 化学系学協会北海道支部冬季研究発表会(Web), 2022, 2022年
  • タンパク質-リガンド複合体解析のためのマイクロ流体デバイスの開発
    舟久保智瑛, 真栄城正寿, 上野剛, 石田晃彦, 谷博文, 渡慶次学, 化学系学協会北海道支部冬季研究発表会(Web), 2022, 2022年
  • マイクロ流体デバイス法による各種ブロックコポリマーナノ粒子の調製と物性および脳内移行性の評価
    吉田圭輝, 金沢貴憲, 飯岡真吾, 真野結奈, 照喜名孝之, 真栄城正寿, 渡慶次学, 近藤啓, 日本薬学会年会要旨集(Web), 142nd, 2022年
  • ミトコンドリア標的型DDSを基盤とした癌光治療の検証
    山田勇磨, 窪田文佳, 高野勇太, BIJU Vasudevanpillai, 真栄城正寿, 渡慶次学, 繁富香織, 宮武由甲子, 原島秀吉, 日本DDS学会学術集会プログラム予稿集, 38th, 2022年
  • コエンザイムQ10搭載ミトコンドリア標的型ナノカプセル注射剤の開発
    日比野光恵, 山田勇磨, 真栄城正寿, 渡慶次学, 原島秀吉, 生体膜と薬物の相互作用シンポジウム講演要旨集, 43rd, 2022年
  • ルシフェラーゼ発現大腸菌の紙デバイスへの固定化と発現誘導
    古坐あすか, 石田晃彦, 真栄城正寿, 谷博文, 渡慶次学, 日本分析化学会年会講演要旨集(Web), 71st, 2022年
  • エクソソームによるリキッドバイオプシーのための標準脂質ナノ粒子の開発
    大山祥大, 丹羽彩由花, 真栄城正寿, 真栄城正寿, 真栄城正寿, 石田晃彦, 谷口正輝, 渡慶次学, 日本分析化学会年会講演要旨集(Web), 71st, 2022年
  • カリウムイオン定量のための距離ベース紙分析デバイスの開発
    才木陸朗, 石田晃彦, 真栄城正寿, 谷博文, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集(CD-ROM), 46th, 2022年
  • 蛍光ナノダイヤモンド搭載セラノスティクス用脂質ナノ粒子の作製
    杉浦魁星, 真栄城正寿, 真栄城正寿, 佐藤悠介, 石田晃彦, 谷博文, 原島秀吉, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集(CD-ROM), 45th, 2022年
  • マイクロ流体デバイスを用いた人工エクソソーム作製法の開発
    丹羽彩由花, 大山祥大, 真栄城正寿, 真栄城正寿, 石田晃彦, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集(CD-ROM), 46th, 2022年
  • タンパク質含有ハイドロゲルによるX線結晶構造解析法の開発
    一町田由貴, 真栄城正寿, 真栄城正寿, 上野剛, 小西真昌, 坂井直樹, 石田晃彦, 谷博文, 山本雅樹, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集(CD-ROM), 45th, 2022年
  • マイクロ流体デバイスを用いた長鎖プラスミドDNA搭載ナノ粒子の作製
    宇野秀哉, 真栄城正寿, 真栄城正寿, 佐藤悠介, 石田晃彦, 原島秀吉, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集(CD-ROM), 46th, 2022年
  • セルロースナノファイバーの乾燥収縮を介した膜融合反応による単一EV統合解析
    川口彰太, 安井隆雄, 安井隆雄, 安井隆雄, 嶋田泰佑, 神谷由紀子, 浅沼浩之, 真栄城正寿, 渡慶次学, 古賀大尚, 村上正晃, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム学会研究会講演要旨集(CD-ROM), 46th, 2022年
  • ミトコンドリア標的型コエンザイムQ10封入ナノカプセル注射剤におけるマイクロ流体デバイスを用いた調製法の構築と治療効果の検証
    日比野光恵, 山田勇磨, 真栄城正寿, 渡慶次学, 原島秀吉, 日本薬学会年会要旨集(Web), 142nd, 2022年
  • ミトコンドリア機能強化を可能とするミトコンドリア成分補充療法の検証
    伊藤百, 山田勇磨, 山田勇磨, 日比野光恵, 佐々木大輔, 真栄城正寿, 渡慶次学, 渡慶次学, 太田善浩, 原島秀吉, 原島秀吉, 日本薬学会年会要旨集(Web), 142nd, 2022年
  • 血中の乳酸とATPの濃度比による重症度診断のための電気化学センサの開発
    九鬼静香, 石田晃彦, 真栄城正寿, 谷博文, 渡慶次学, Chemical Sensors, 37, Supplement B, 2021年
  • ポータブル蛍光偏光測定装置を用いたヒト血清中の抗SARS-CoV-2抗体の検出
    高橋和希, 西山慶音, 福山真央, 粕谷素洋, 真栄城正寿, 石田晃彦, 谷博文, 重村幸治, 火原彰秀, 渡慶次学, 分析化学討論会講演要旨集(Web), 81st, 2021年
  • エタノール混合によるベシクル構造転移:マルチラメラ形成機構
    柴田果奈, 真栄城正寿, 渡慶次学, 篠田渉, 篠田渉, 分子シミュレーション討論会講演要旨集, 35th (CD-ROM), 2021年
  • 血中の乳酸とATPの濃度比による重症度診断のための電気化学センサの開発
    九鬼静香, 石田晃彦, 真栄城正寿, 谷博文, 渡慶次学, 電気化学秋季大会講演要旨集(CD-ROM), 2021, 2021年
  • ミトコンドリア標的型光線力学的療法を可能とするナノキャリアの構築及び機能評価
    窪田文佳, 山田勇磨, SATRIALDI, 高野勇太, 真栄城正寿, 渡慶次学, 原島秀吉, 生体膜と薬物の相互作用シンポジウム講演要旨集, 42nd (CD-ROM), 2021年
  • マイクロ流体デバイスを用いたプラスミドDNA搭載脂質ナノ粒子の作製
    宇野秀哉, 真栄城正寿, 真栄城正寿, 佐藤悠介, 石田晃彦, 谷博文, 原島秀吉, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 43rd, 2021年
  • 蛍光偏光免疫分析法によるオカダ酸の検出
    千田駿亮, 高橋和希, 福山真央, 粕谷素洋, 真栄城正寿, 石田晃彦, 谷博文, ZHERDEV Anatoly V., EREMIN Sergei A., EREMIN Sergei A., 火原彰秀, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集(CD-ROM), 44th, 2021年
  • Affibodyを用いた非競合蛍光偏光免疫分析法によるEGFRの検出
    高橋和希, 福山真央, 粕谷素洋, 真栄城正寿, 石田晃彦, 谷博文, 火原彰秀, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集(CD-ROM), 44th, 2021年
  • ミトコンドリア運搬用DDS(Trans MIT system)の開発
    山田勇磨, 山田勇磨, 日比野光恵, 伊藤百, 荒井愛永, 佐々木大輔, 真栄城正寿, 渡慶次学, 渡慶次学, 太田善浩, 原島秀吉, 原島秀吉, 日本薬剤学会年会講演要旨集(CD-ROM), 36th, 2021年
  • リンパ節送達とリンパ節内分布に影響を与える脂質ナノ粒子特性
    中村孝司, 河合美典, 佐藤悠介, 真栄城正寿, 渡慶次学, 原島秀吉, 日本薬剤学会年会講演要旨集(CD-ROM), 36th, 2021年
  • マイクロ流体デバイスによる高分子ナノ粒子の調製条件に関する基礎的検討
    飯岡真吾, 日比野光恵, 山田勇磨, 真栄城正寿, 渡慶次学, 照喜名孝之, 金沢貴憲, 近藤啓, 日本薬学会年会要旨集(Web), 141st, 2021年
  • 蛍光偏光免疫測定法によるヒト血清中の抗SARS-CoV-2抗体の検出
    高橋和希, 西山慶音, 福山真央, 粕谷素洋, 真栄城正寿, 石田晃彦, 谷博文, 火原彰秀, 渡慶次学, キャピラリー電気泳動シンポジウム講演要旨集, 40th (CD-ROM), 2020年
  • ナノ構造体を用いた脂質ナノ粒子のサイズ分離
    清水一樹, 真栄城正寿, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 分析化学討論会講演要旨集(Web), 80th, 2020年
  • ペーパーデバイスによる懸濁試料の簡易・迅速分析のための前処理ユニットの開発
    前田陵我, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 分析化学討論会講演要旨集(Web), 80th, 2020年
  • 血中リチウムイオン測定のための全自動分析システムの開発
    小松雄士, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 分析化学討論会講演要旨集(Web), 80th, 2020年
  • ポータブルHPLCのためのLEDおよびフォトダイオードを用いた小型吸光検出モジュールの開発
    西村卓馬, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 分析化学討論会講演要旨集(Web), 80th, 2020年
  • ルシフェラーゼの活性制御に基づくオンチップ生物発光アッセイの開発
    野中康伸, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 分析化学討論会講演要旨集(Web), 80th, 2020年
  • 常温X線結晶構造解析のためのマイクロデバイスの開発
    舟久保智瑛, 真栄城正寿, 真栄城正寿, 伊藤翔, 伊藤翔, 上野剛, 石田晃彦, 谷博文, 山本雅貴, 渡慶次学, 分析化学討論会講演要旨集(Web), 80th, 2020年
  • 生物発光分析のためのペーパーデバイスの開発とキナーゼ分析への応用
    高田一生, 渡慶次学, 谷博文, 石田晃彦, 真栄城正寿, 分析化学討論会講演要旨集(Web), 80th, 2020年
  • 高感度免疫分析デバイスの開発とH5型鳥インフルエンザウイルス検出への応用
    西山慶音, RAMOS Kenia Chavez, 真栄城正寿, 石田晃彦, 谷博文, 笠間敏博, 馬場嘉信, 渡慶次学, 分析化学討論会講演要旨集(Web), 80th, 2020年
  • 乳酸/ATPの血中濃度比による重症度診断のための電気化学酵素センサーの開発
    九鬼静香, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 分析化学討論会講演要旨集(Web), 80th, 2020年
  • プロゲステロンの迅速かつ簡便な測定のための紙を基材とするマイクロデバイスの開発
    小松雄士, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 日本化学会春季年会講演予稿集(CD-ROM), 100th, 2020年
  • 紙ベースイムノアッセイのための抗体の簡便な固定化法
    前田陵我, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 42nd (Web), 2020年
  • ナノ構造体搭載デバイスによる脂質ナノ粒子のサイズ分離
    清水一樹, 真栄城正寿, 真栄城正寿, 石田晃彦, 谷博文, 西井準治, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 42nd (Web), 2020年
  • 脂質ナノ粒子のサイズと電荷がリンパ節移行とリンパ節内分布に与える影響
    中村孝司, 河合美典, 佐藤悠介, 真栄城正寿, 渡慶次学, 原島秀吉, 日本薬学会年会要旨集(CD-ROM), 140th (Web), 2020年
  • CRISPR/Casタンパク質搭載脂質ナノ粒子の開発
    佐藤悠介, 鈴木裕一, 小沼はるの, 佐藤里咲, 真栄城正寿, 渡慶次学, 原島秀吉, 日本DDS学会学術集会プログラム予稿集, 36th, 2020年
  • コエンザイムQ10封入ミトコンドリア標的型DDSの開発およびアセトアミノフェン肝障害モデルへの治療効果の検証
    日比野光恵, 山田勇磨, 真栄城正寿, 渡慶次学, 石塚洋一, 原島秀吉, 日本DDS学会学術集会プログラム予稿集, 36th, 2020年
  • ガラス製マイクロ流体デバイスを用いたsiRNA搭載脂質ナノ粒子の作製と大量生産用集積化デバイスの開発
    真栄城正寿, 真栄城正寿, 岡田悠斗, 佐藤悠介, 石田晃彦, 谷博文, 原島秀吉, 渡慶次学, 日本DDS学会学術集会プログラム予稿集, 36th, 2020年
  • DDSナノ粒子作製用ガラス製マイクロ流体デバイスの開発
    岡田悠斗, 真栄城正寿, 真栄城正寿, 佐藤悠介, 石田晃彦, 谷博文, 原島秀吉, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 42nd (Web), 2020年
  • マイクロデバイスを用いたタンパク質結晶の室温複合体構造解析
    竹田怜央, 真栄城正寿, 真栄城正寿, 伊藤翔, 伊藤翔, 上野剛, 石田晃彦, 谷博文, 山本雅貴, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 42nd (Web), 2020年
  • UNDERSTANDING THE LIPID NANOPARTICLES STRUCTURE DYNAMICS USING A TIME-RESOLVED SAXS MEASUREMENT
    Masatoshi Maeki, Niko Kimura, Kazuki Shimizu, Kento Yonezawa, Nobutaka Shimizu, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi, Proc. Micro TAS 2019, 1478, 1479, 2019年10月, [査読有り]
    This paper reports a time-resolved small angle X-ray scattering (SAXS) for understanding lipid nanoparticles (LNPs) structure dynamics. The structure and its dynamics are the indispensable factors to ensure the activity and therapeutic effect of LNP-based nanomedicines. However, the structure dynamics of LNPs are not well understood because of the limitation of measurement methodology. To overcome the problem, we developed microfluidic-based SAXS measurement technique combined with a synchrotron X-ray source. We confirmed the LNPs decomposition process and LNPs aggregation process by pH change of the solution., 英語
  • PORTABLE FLUORESCENCE POLARIZATION ANALYZER FOR ON-SITE MULTISAMPLE IMMUNOASSAY
    Ayano Nakamura, Osamu Wakao, Ken Satou, Mitsutoshi Aoyagi, Kazuhiko Nishimura, Chikaaki Mizokuchi, Ken Sumiyoshi, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Koji Shigemura, Akihide Hibara, Manabu Tokeshi, Proc. Micro TAS 2019, 1393, 1394, 2019年10月, [査読有り]
    This paper reports on a portable fluorescence polarization (FP) analyzer capable of on-site multisample immunoassay. The FP analyzer is small-size (W × D × H = 65 cm3), low cost (< $5,000), and high throughput (96 samples simultaneously). Using this analyzer, we demonstrated FP immunoassay (FPIA) for deoxynivalenol (DON), one of several mycotoxins that frequently infect wheat and other grains, spiked into wheat samples. The assay with the compact FP analyzer had sufficient accuracy to quantify DON in wheat in comparison with LC-MS/MS. Furthermore, multisample immunoassay was conducted by using a microdevice with 96 chambers., 英語
  • DEVELOPMENT OF A THREE-DIMENSIONAL MICROMIXER DEVICE FOR PRODUCTION OF VARIOUS LIPID-BASED NUCLEIC ACID NANOCARRIERS
    Niko Kimura, Masatoshi Maeki, Yusuke Sato, Kosuke Sasaki, Akihiko Ishida, Hirofumi Tani, Hideyoshi Harashima, Manabu Tokeshi, Proc. Micro TAS 2019, 368, 369, 2019年10月, [査読有り]
    This paper describes development of a three-dimensional (3D) baffle mixer device for precise size control of various types of lipid nanoparticles (LNPs) with high encapsulation efficiency of short interfering RNAs (siRNAs). The 3D baffle mixer device achieved more precise size control of various LNPs than that of the conventional micromixer device. In addition, the 3D baffle mixer enabled effective capturing of siRNAs into LNPs without any assistance of electrostatic interaction between lipid molecules and siRNAs. The 3D baffle mixer device is expected to become one of the key platforms for production of novel lipid-based nucleic acid nanocarriers., 英語
  • HIGH-THROUGHPUT X-RAY CRYSTALLOGRAPHY BASED ON THE PROTEIN CRYASTAL ARRAY
    Reo Takeda, Masatoshi Maeki, Sho Ito, Go Ueno, Kunio Hirata, Akihiko Ishida, Hirofumi Tani, Masaki Yamamoto, Manabu Tokeshi, Proc. Micro TAS 2019, 191, 192, 2019年10月, [査読有り]
    This paper reports development of a microfluidic-based high-throughput X-ray crystallography for protein-ligand complex structure analysis. Three-dimensional (3D) structure analysis of a protein-ligand complex requires complicated procedures. To improve the throughput performance, we developed a protein crystal array-based microfluidic device. The microfluidic device can effectively capture protein microcrystals into the microarray and continuously prepare protein-ligand complex samples. We determined lysozyme- p-toluenesulfonic acid complex and thaumatin-selenourea complex structures by serial on-chip X-ray diffraction measurement at room temperature., 英語
  • FLUORESCENCE SIGNAL AMPLIFICATION FOR SENSITIVE ENZYME IMMUNOASSAY UTILIZING AN IMMUNO-WALL
    Keine Nishiyama, Toshihiro Kasama, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Yoshinobu Baba, Manabu Tokeshi, Proc. Micro TAS 2019, 689, 690, 2019年10月, [査読有り]
    This paper reports a novel method of signal amplification based on the accumulation of enzymatic fluorescent products at a wall-like structure (immuno-wall) in a microchannel for sensitive immunoassay. We found the function of an immuno-wall as a media for the enrichment of fluorescence molecules. We combined this function with the amplification of the fluorescence signal by an enzymatic reaction to produce a synergistic effect. The performance of the device was evaluated with human C-reactive protein (CRP) as a model target. The limit of detection of CRP was 2.5 pg/mL. This value was approximately 3 orders of magnitude lower than that obtained with a fluorescent dye-labeled antibody (1.7 ng/mL)., 英語
  • 実験計画法によるmRNA送達キャリアの効率的な最適化
    橋場月, 佐藤悠介, 真栄城正寿, 渡慶次学, 原島秀吉, 日本核酸医薬学会年会講演要旨集, 5th, 2019年
  • メタン代謝酵素を用いたメタン特異的な分析手法の開発
    清田雄平, 真栄城正寿, 渡慶次学, 宮崎真佐也, 分析化学討論会講演要旨集, 79th, 2019年
  • フローデバイスを用いたフルオレセイン振動化学発光
    池田晋吾, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 分析化学討論会講演要旨集, 79th, 2019年
  • ゲノム編集タンパク質搭載脂質ナノ粒子の開発
    佐藤悠介, 鈴木裕一, 佐藤里咲, 真栄城正寿, 渡慶次学, 原島秀吉, 日本核酸医薬学会年会講演要旨集, 5th, 2019年
  • マイクロデバイスを用いたタンパク質-リガンド複合体構造解析
    真栄城正寿, 真栄城正寿, 竹田怜央, 伊藤翔, 伊藤翔, 上野剛, 平田邦生, 石田晃彦, 谷博文, 山本雅貴, 渡慶次学, 分析化学討論会講演要旨集, 79th, 2019年
  • 電気浸透流ポンプとオンチップカラムに基づく可搬型イオンクロマトグラフの開発
    石田晃彦, 西村卓馬, 真栄城正寿, 谷博文, 渡慶次学, イオンクロマトグラフィー討論会講演要旨集, 36th, 2019年
  • マイクロ流体デバイス:薬剤学研究・開発のツールとして
    西山慶音, 木村笑, 真栄城正寿, 渡慶次学, 薬剤学(Web), 79, 3, 2019年
  • 核酸搭載脂質ナノ粒子の動的構造解析
    真栄城正寿, 真栄城正寿, 木村笑, 清水一樹, 石田晃彦, 谷博文, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 40th, 2019年
  • 核酸ナノキャリア製造のための新規バッフルデバイスの開発
    木村笑, 真栄城正寿, 真栄城正寿, 石田明彦, 谷博文, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 40th, 2019年
  • 蛍光偏光免疫分析法によるH5亜型鳥インフルエンザウイルスの検出
    西山慶音, 武田洋平, 真栄城正寿, 石田晃彦, 谷博文, 重村幸治, 火原彰秀, 小川晴子, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 40th, 2019年
  • マイクロデバイスを用いたX線結晶構造解析の高速化とリガンドスクリーニングへの応用
    竹田怜央, 真栄城正寿, 真栄城正寿, 伊藤翔, 伊藤翔, 上野剛, 平田邦夫, 石田晃彦, 谷博文, 山本雅貴, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 39th, 2019年
  • 脂質ナノ粒子形成後の二次希釈操作が粒子サイズへ与える影響の解明
    木村笑, 真栄城正寿, 岡部奈々, 佐藤悠介, 石田晃彦, 谷博文, 原島秀吉, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 39th, 2019年
  • マイクロ流路デバイスによるメタン分析のための新規メタン特異的検出法の開発
    清田雄平, 真栄城正寿, 渡慶次学, 宮崎真佐也, 宮崎真佐也, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 39th, 2019年
  • 小角X線溶液散乱法による脂質ナノ粒子の動的構造解析法の開発
    真栄城正寿, 木村笑, 石田晃彦, 谷博文, 渡慶次学, 日本分析化学会年会講演要旨集(Web), 68th, 2019年
  • 電気浸透流ポンプとオンチップカラムに基づくオールインワンコンパクトLCシステムの開発
    石田晃彦, 西村卓馬, 真栄城正寿, 谷博文, 渡慶次学, 日本分析化学会年会講演要旨集(Web), 68th, 2019年
  • Bioanalysis: Applications of Microfluidic Systems in Biology and Medicine               
    Tokeshi Manabu, Daisuke Onoshima, Hiroshi Yukawa, Yoshinobu Baba, Bioanalysis: Applications of Microfluidic Systems in Biology and Medicine, 7, 275, 300, 2019年
    英語, その他
  • Microfluidic stepwise and rapid ethanol dilution for precise size control of lipid nanoparticles               
    Niko Kimura, Masatoshi Maeki, Nana Okabe, Yusuke Sato, Akihiko Ishida, Hirofumi Tani, Hideyoshi Harashima, Manabu Tokeshi, Proc. Micro TAS 2018, 1404, 1405, 2018年11月, [査読有り]
    英語
  • MICROSCOPIC REAL-TIME MEASUREMENT OF PROTEIN CRYSTAL GROWTH IN MICROFLUIDIC DEVICES
    Masatoshi Maeki, Shohei Yamazaki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi, Proc. Micro TAS 2018, 4, 2192, 2193, 2018年11月, [査読有り]
    This paper reports a microscopic real-time measurement of protein crystal growth in microfluidic devices to understand the effect of micro space on the protein crystal growth. Lysozyme crystallization behavior was observed using an optical microscope and we found that the orientation percentage of the (1 1 0) phase was depending on the depth of the crystallization chambers. The concentration profile and growth rate of lysozyme crystal in the microfluidic device was determined by in situ Raman spectroscopy and laser confocal microscopy-combined with differential interference contrast microscopy (LCM-DIM). The crystal growth rate in 10 and 20 μm depth crystallization chamber was 10 times slower than that of the other devices., 英語
  • ナノピラーデバイスを用いたDNAのサイズ分離と無標識検出               
    阿尻 大雅, 安井 隆雄, 笠 晴也, 真栄城 正寿, 石田 晃彦, 谷 博文, 西井 準治, 馬場 嘉信, 渡慶次 学, 日本分析化学会講演要旨集, 67年会, 125, 125, 2018年08月
    (公社)日本分析化学会, 日本語
  • 電気化学検出液体クロマトグラフィーチップの開発とその尿中シュウ酸分析への応用
    藤井大地, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 化学系学協会北海道支部冬季研究発表会(Web), 2018, 2018年
  • マイクロ流体デバイスにおけるルミノール化学発光の増感効果
    菊地優仁, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 化学系学協会北海道支部冬季研究発表会(Web), 2018, 2018年
  • マイクロデバイスを用いた小麦中デオキシニバレノールの多サンプル同時蛍光偏光免疫分析
    中村彩乃, 若尾摂, 佐藤憲, 住吉研, 真栄城正寿, 石田晃彦, 谷博文, 重村幸治, 火原彰秀, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 37th, 2018年
  • 微小空間内におけるリゾチームの結晶化制御および晶析挙動解析
    山崎翔平, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 化学系学協会北海道支部冬季研究発表会(Web), 2018, 2018年
  • マイクロデバイスを用いた小麦中デオキシニバレノールの多サンプル同時蛍光偏光免疫分析
    中村彩乃, 若尾摂, 佐藤憲, 住吉研, 真栄城正寿, 石田晃彦, 谷博文, 重村幸治, 火原彰秀, 渡慶次学, 化学とマイクロ・ナノシステム, 17, 2, 2018年
  • オンチップ液体クロマトグラフィーのためのウォールジェット式電気化学検出器の開発
    干川晃生, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 日本分析化学会年会講演要旨集, 67th, 2018年
  • マイクロデバイスを用いた小型蛍光偏光測定装置の開発とその応用
    中村彩乃, 若尾摂, 佐藤憲, 溝口親明, 住吉研, 黒澤文夫, 真栄城正寿, 石田晃彦, 谷博文, 重村幸治, 火原彰秀, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 38th, 2018年
  • ペーパーデバイスによるPOCTのための高感度競合イムノアッセイの実現
    前田陵我, 小松雄士, 佐藤優樹, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 38th, 2018年
  • ハイスループット蛍光偏光イムノアッセイデバイスの開発
    若尾摂, 中村彩乃, 佐藤憲, 溝口親明, 住吉研, 黒澤文夫, 真栄城正寿, 石田晃彦, 谷博文, 重村幸治, 火原彰秀, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 38th, 2018年
  • シクロデキストリンと両親媒性物質を用いたホタルルシフェラーゼの活性制御と生物発光分析法への応用
    工藤裕貴, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 分析化学討論会講演要旨集, 78th, 2018年
  • 固定化酵素の再活性化法の開発とマイクロリアクターへの応用
    清田雄平, 山口浩, 真栄城正寿, 渡慶次学, 宮崎真佐也, 宮崎真佐也, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 38th, 2018年
  • 酵素免疫測定法を利用した高感度イムノウォールデバイスの開発
    西山慶音, 笠間敏博, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 38th, 2018年
  • ペーパーデバイスによるリチウムイオン濃度測定
    小松雄士, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 化学系学協会北海道支部冬季研究発表会(Web), 2018, 2018年
  • 微小空間におけるタンパク質結晶成長のリアルタイム計測
    竹田怜央, 山崎翔平, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 38th, 2018年
  • イムノウォールデバイスの開発と遺伝子変異たんぱく質の検出
    中股征哉, 笠間敏博, 笠間敏博, 長谷哲成, 與語直之, 與語直之, 小沢直也, 真栄城正寿, 石田晃彦, 佐藤光夫, 加地範匡, 谷博文, 長谷川好規, 馬場嘉信, 馬場嘉信, 渡慶次学, 化学系学協会北海道支部冬季研究発表会(Web), 2018, 2018年
  • iLiNPデバイスによるpH応答性カチオン性脂質ナノ粒子の粒径制御
    木村笑, 真栄城正寿, 岡部奈々, 佐藤悠介, 石田晃彦, 谷博文, 原島秀吉, 渡慶次学, 渡慶次学, 渡慶次学, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 37th, 2018年
  • 新規製造現場での基盤技術 脂質ナノ粒子作製用マイクロ流体デバイス
    木村笑, 真栄城正寿, 渡慶次学, ケミカルエンジニヤリング, 63, 6, 2018年
  • Microfluidic immunoassay devices as next-generation cancer and medical diagnostics platform
    Toshihiro Kasama, Yoshinobu Baba, Manabu Tokeshi, Next Generation Point-of-care Biomedical Sensors Technologies for Cancer Diagnosis, 305, 322, 2017年12月30日
  • A Small-Sized Lipid Nanoparticles Production Method Using Microfluidic Devices with Baffle Structures
    N. Kimura, M. Maeki, Y. Sato, A. Ishida, H. Tani, H. Harashima, M. Tokeshi, Proc. Micro TAS 2017, 965, 966, 2017年10月
    This paper reports a lipid nanoparticles (LNP) production method and its formation behavior using microfluidic devices with baffle structures. The microfluidic devices showed great mixing efficiency at 500 μL/min, and we achieved 20 nm-sized LNPs production that chaotic micromixers were not able to produce at the same flow rate condition. Additionally, we found that the smaller-sized LNPs/siRNA prepared by baffle structures have higher penetration efficiency than that of the larger-sized LNPs, but all of them showed the gene silencing activity. The microfluidic devices with baffle structures are expected to be a practicable apparatus for DDSs application., 英語
  • High-Throughput Fluorescence Polarization Measurement System Towards Molecular Interaction Analysis
    O. Wakao, M. Maeki, A. Ishida, H. Tani, A. Hibara, M. Tokeshi, Proc. Micro TAS 2017, 557, 558, 2017年10月, [査読有り]
    This report demonstrated simultaneous fluorescence polarization (FP) measurement for 100 samples. The measurement was based on the synchronization detection between the switching of a liquid crystal (LC) layer and the sampling rate of an image sensor. This offered captured FP signals from multisample as single FP image, and the values of FP signals were obtained separately by image analysis. The results showed the analytical performance of our system was comparable to that of conventional apparatus and which implies our system can be applicable to molecular interaction analysis., 英語
  • A Microfluidic-Based Technique for Creating Amyloid Nanostructures and Its Application to Enzyme Reaction
    M. Maeki, S. Sato, A. Ishida, H. Tani, M. Tokeshi, Proc. Micro TAS 2017, 1279, 1280, 2017年10月, [査読有り]
    This paper reports a bottom-up fabrication technique of amyloid nanostructures and its application to an enzyme immobilized microfluidic device. The process consists 3 steps: (1) immobilization of lysozymes, (2) denaturation and growth of amyloid fibrils, and (3) immobilization of enzymes on the amyloid fibrils. The growth of amyloid fibrils was able to control by the concentration of lysozyme solution and incubation time. We evaluated the performance of enzyme immobilized amyloid fibrils by hydrolysis reaction. As a results, synthetic peptides and proteins were effectively digested compared with conventional method., 英語
  • 分子間相互作用測定のための多サンプル同時蛍光偏光測定システムの開発
    若尾摂, 住吉研, 溝口親明, 真栄城正寿, 石田晃彦, 谷博文, 重村幸治, 火原彰秀, 渡慶次学, センサ・マイクロマシンと応用システムシンポジウム(CD-ROM), 34th, 2017年
  • 小型蛍光偏光イムノアッセイ装置の開発
    若尾摂, 住吉研, 溝口親明, 真栄城正寿, 石田晃彦, 谷博文, 重村幸治, 火原彰秀, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 36th, 2017年
  • 微小空間によるタンパク質結晶化制御と分光法を用いた晶析挙動解析
    山崎翔平, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 36th, 2017年
  • マイクロデバイスを用いたアミロイド構造体作製法の開発と酵素反応への応用
    真栄城正寿, 佐藤紗耶, 石田晃彦, 谷博文, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 36th, 2017年
  • 高効率免疫分析を可能とするイムノウォールデバイスの開発
    中股征哉, 笠間敏博, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 36th, 2017年
  • DNA分離のためのナノピラーデバイス作製の簡便化とその応用
    阿尻大雅, 安井隆雄, 安井隆雄, 笠晴也, 真栄城正寿, 石田晃彦, 谷博文, 西井準治, 馬場嘉信, 馬場嘉信, 渡慶次学, 渡慶次学, キャピラリー電気泳動シンポジウム講演要旨集, 37th, 2017年
  • バッフル構造を配置した流路デザインによる粒径の精密制御
    木村笑, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 35th, 2017年
  • マイクロデバイスを用いた脂質ナノ粒子作製と生体内動態挙動
    真栄城正寿, 木村笑, 佐藤悠介, 石田晃彦, 谷博文, 原島秀吉, 渡慶次学, 化学工学会秋季大会研究発表講演要旨集(CD-ROM), 49th, 2017年
  • バッフル構造を配置した流路デザインによる粒径の精密制御
    木村笑, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 化学とマイクロ・ナノシステム, 16, 2, 2017年
  • Nanopillars, Nanowires and Nanoballs for DNA and Protein Analysis
    Noritada Kaji, Takao Yasui, Manabu Tokeshi, Yoshinobu Baba, RSC Nanoscience and Nanotechnology, 2017-January, 41, 76, 98, 2017年
    © The Royal Society of Chemistry 2017. Recent development of nanofluidic devices using nanopillars, nanowires, and nanoballs for high-performance biomolecules analysis are reviewed in this chapter. Two approaches, "top-down" fabrication techniques and "bottom-up" self-assemble techniques, were applied to construct nanospace inside microchannels, and various biomolecules including DNA, RNA and proteins were successfully separated within a few seconds. These separation techniques enabled high throughput analysis that had never achieved by natural or synthetic polymers and explored a new bioanalytical field based on molecular dynamics in nanospace. Hybrid use of the both approaches might be promising for future home diagnostic devices and clinical applications.
  • Development of a New Technique for Washing Steps in Multistep Assays Using Microfluidic Paper-based Analytical Devices
    Saeed Mohammadi, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Manabu Tokeshi, Proceedings of MicroTAS 2016, 970, 971, 2016年10月, [査読有り]
    This paper presents a novel washing technique for microfluidic paper-based analytical devices (μPADs) to remove unbound antigen or antibodies from paper substrates in multistep assays and achieve higher sensitivity and reproducibility relying on spontaneous capillary force of the paper., 英語, 記事・総説・解説・論説等(国際会議プロシーディングズ)
  • Fluorescence Polarization-based Multiple Samples Detection Using Microchamber Array Towards High-throughput Molecular Interaction Analysis
    Osamu Wakao, Masatoshi Maeki, Akihiko Ishida, Hirofumi Tani, Akihide Hibara, Manabu Tokeshi, Proceedings of MicroTAS 2016, 1400, 1401, 2016年10月, [査読有り]
    We report a new high-throughput homogeneous assay format using a microchamber array towards molecular interactions analysis. The assay format is based on the fluorescence polarization (FP) detection using liquid-crystal display (LCD) that can switches a direction of FP by changing its images. In this work, we demonstrate a multiple sample FP immunoassay (FPIA) of prostaglandin E2 in a microchamber array to simultaneously analyze 25 samples. FP signals were imaged simultaneously and their values were acquired separately. This result showed our format with high-throughput had a measurement performance comparable to that of a conventional apparatus designed to single analysis., 英語, 記事・総説・解説・論説等(国際会議プロシーディングズ)
  • Micro/Nano Devices for Chemical Analysis
    Manabu Tokeshi, Kiichi Sato, MICROMACHINES, 7, 9, 2016年09月
    MDPI AG, 英語, その他
  • マイクロ分析チップの新たな可能性               
    渡慶次学, 真栄城正寿, JPCA NEWS, 576, 8, 13, 2016年09月, [招待有り]
    日本語, 記事・総説・解説・論説等(商業誌、新聞、ウェブメディア)
  • がん診断のためのエクソソーム分析法の開発               
    阿尻 大雅, 安井 隆雄, 真栄城 正寿, 石田 晃彦, 谷 博文, 馬場 嘉信, 渡慶次 学, 日本分析化学会講演要旨集, 65年会, 165, 165, 2016年08月
    (公社)日本分析化学会, 日本語
  • マイクロ流体デバイスによる脂質ナノ粒子作製とDDSへの応用
    真栄城正寿, 佐藤悠介, 原島秀吉, 渡慶次学, 機能材料, 36, 7, 15, 21, 2016年07月, [招待有り]
    シーエムシー出版, 日本語, 記事・総説・解説・論説等(商業誌、新聞、ウェブメディア)
  • 分子間相互作用測定のための蛍光偏光イメージングシステムの開発
    若尾摂, 真栄城正寿, 石田晃彦, 谷博文, 火原彰秀, 渡慶次学, 分析化学討論会講演要旨集, 76th, 2016年
  • マイクロデバイスを用いたクロラムフェニコールの蛍光偏光免疫測定
    青木琴, 若尾摂, 真栄城正寿, 石田晃彦, 谷博文, EREMIN Sergei, 渡慶次学, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 33rd, 2016年
  • 蛍光偏光イメージングによる複数サンプルの同時イムノアッセイ
    若尾摂, 真栄城正寿, 石田晃彦, 谷博文, 火原彰秀, 渡慶次学, 化学系学協会北海道支部冬季研究発表会講演要旨集(CD-ROM), 2016, 2016年
  • ATP測定のための電気化学酵素センサーの開発
    西山慶音, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 化学系学協会北海道支部冬季研究発表会講演要旨集(CD-ROM), 2016, 2016年
  • マイクロチップ電気化学検出LCデバイスの生体試料分析への応用
    藤井大地, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 日本分析化学会年会講演要旨集, 65th, 2016年
  • ルシフェラーゼ内封リポソームを用いたオンチップイムノアッセイ
    中谷友祐, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 化学系学協会北海道支部冬季研究発表会講演要旨集(CD-ROM), 2016, 2016年
  • マイクロデバイスによるタンパク質の立体構造解析
    真栄城正寿, 真栄城正寿, 山崎翔平, 杉島正一, 渡邉啓一, 石田晃彦, 谷博文, 宮崎真佐也, 渡慶次学, 分析化学討論会講演要旨集, 76th, 2016年
  • PDMS製チップホルダーを用いたペーパーマイクロ分析チップの開発
    MOHAMMADI Saeed, BUSA Lori Shayne Alamo, 真栄城正寿, 石田晃彦, 谷博文, 渡慶次学, 渡慶次学, 渡慶次学, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 34th, 2016年
  • 脳腫瘍の完全切除を目指した術中遺伝子変異診断
    笠間敏博, 笠間敏博, 笠間敏博, 山道茜, 山道茜, 大岡史治, 加藤幸成, 加藤彰, 平野雅規, LUSHUN Chalise, 栗本路弘, 近藤五郎, 青木恒介, 鈴木啓道, 本村和也, 加地範匡, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 渡慶次学, 松原年生, 鈴木秀鎌, 若林俊彦, 夏目敦至, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 34th, 2016年
  • 新規迅速解析デバイスを用いたグリオーマIDH1遺伝子変異の術中診断とその応用
    山道茜, 山道茜, 大岡史治, 笠間敏博, 笠間敏博, 鈴木啓道, 青木恒介, 本村和也, 平野雅規, RANJIT Melissa, CHALISE Lushun, 栗本路弘, 近藤五郎, 加地範匡, 渡慶次学, 松原年生, 鈴木秀謙, 馬場嘉信, 加藤幸成, 木村晋也, 若林俊彦, 夏目敦至, 日本脳腫瘍学会プログラム・抄録集, 34th, 2016年
  • がん診断のためのエクソソームの無標識検出
    阿尻大雅, 安井隆雄, 安井隆雄, 石田晃彦, 谷博文, 真栄城正寿, 馬場嘉信, 馬場嘉信, 渡慶次学, 渡慶次学, 化学系学協会北海道支部冬季研究発表会講演要旨集(CD-ROM), 2016, 2016年
  • Immuno-wall lab-on-a-chip protein analysis devices for high precision surgery of gliomas
    T. Kasama, A. Yamamichi, F. Ohka, Y. Kato, H. Suzuki, A. Kato, K. Motomura, M. Hirano, M. Ranjit, L. Chalise, M. Kurimoto, G. Kondo, K. Aoki, N. Kaji, T. Matsubara, H. Suzuki, M. Tokeshi, T. Wakabayashi, A. Natsume, Y. Baba, 20th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2016, 651, 652, 2016年, [査読有り]
    In the present study, we propose immuno-wall lab-on-a-chip protein analysis devices for ultrarapid detection of R132H mutant isocitrate dehydrogenase 1 (IDH1) that we identified as a specifically and commonly expressed gene in diffusely infiltrative gliomas1. In 9 min immunoassay, we successfully carried out specific detection of R132H mutant IDH1 in a lysate of glioma tissue, which is much faster than intraoperative pathological diagnosis. Moreover, clinical samples from 10 patients with gliomas were analyzed by using the immuno-wall devices. These results were consistent with those of PCR-based genetic mutation detection method. Our devices realize point-of-care tumor testing, resulting in the high precision surgery of gliomas., 英語, 速報,短報,研究ノート等(学術雑誌)
  • Effects of the grooved structures and the ethanol concentration on the small-sized lipid nanoparticles formation
    Y. Fujishima, M. Maeki, Y. Sato, T. Yasui, A. Ishida, H. Tani, Y. Baba, H. Harashima, M. Tokeshi, 20th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2016, 1412, 1413, 2016年, [査読有り]
    This paper describes lipid nanoparticles (LNPs) formation behavior in microfluidic devices equipped with the staggered herringbone micromixers (SHM) in order to control the LNPs size precisely. Three types of microfluidic devices with different heights of mixer structures were fabricated to examine the effect of mixer structure on the LNPs formation behavior. We found the height of the grooved structures, the lipid concentration, and the ethanol concentration were significant factors for controlling LNPs size and its distribution., 英語, 記事・総説・解説・論説等(国際会議プロシーディングズ)
  • 液晶ディスプレイを利用した蛍光偏光イメージング
    若尾摂, 真栄城正寿, 火原彰秀, 渡慶次学, ケミカルエンジニアリング, 6, 1, 12, 17, 2016年01月, [招待有り]
    化学工業社, 日本語, 記事・総説・解説・論説等(商業誌、新聞、ウェブメディア)
  • マイクロ化学チップの最新動向:紙チップとタンパク質結晶構造解析チップ               
    真栄城正寿, 渡慶次学, クリーン・テクノロジー, 25, 11, 1, 4, 2015年11月, [招待有り]
    日本語, 記事・総説・解説・論説等(商業誌、新聞、ウェブメディア)
  • Fluorescence Polarization Imaging for Multisample Immunoassay
    若尾摂, 真栄城正寿, 石田晃彦, 谷博文, 火原彰秀, 渡慶次学, Proceedings of MicroTAS 2015, 1816, 1818, 2015年10月, [査読有り]
    This paper reports a unique fluorescence polarization (FP) imaging system with a microchip applicable to multisample simultaneous FP immunoassay. The measurement principle of the system has already been reported [1]. In this work, we present a FP imaging immunoassay for multisample of physiologically active substances (prostaglandin E2, PGE2). FP signals of all samples in the captured by an image sensor were imaged simultaneously, and their values were acquired separately from the image analysis. The analytical performance of this assay system was comparable to that of conventional apparatus. The result is the first demonstration of the multisample FP imaging immunoassay., 英語, 記事・総説・解説・論説等(国際会議プロシーディングズ)
  • W221004 マイクロ流体デバイスを利用した医療応用
    渡慶次 学, 年次大会 : Mechanical Engineering Congress, Japan, 2015, "W221004, 1"-"W221004-4", 2015年09月13日
    Microfluidic devices have great potential for medical and life science applications. Recent progresses in microfluidic devices have enabled precise analysis of a small amount of proteins and drugs in blood or urine, and preparation of highly functional nanoparticles. We have developed that several immunoassay systems using the microfluidic devices for rapid diagnosis of biomakers, and have fabricated a novel non-viral gene delivery vector, lipid nanoparticles using the microfluidic devices. In this presentation, I will present about several topics: on-chip immunoassay using hydrogel pillars, fabrication of functional nanoparticles for drug delivery system, and so forth. Moreover, future challenges and potentials of microfluidic devices for biotechnology, medicine, and clinical diagnostics will be also discussed, 一般社団法人日本機械学会, 日本語
  • Development of Microfluidic Devices for Rapid, Low-Cost Detection of EGFR Mutations in Cytological Samples from Patients with Lung Cancer
    Tetsunari Hase, Toshihiro Kasama, Nanako Nishiwaki, Naoyuki Yogo, Mitsuo Sato, Noritada Kaji, Masashi Kondo, Manabu Tokeshi, Yoshinobu Baba, Yoshinori Hasegawa, JOURNAL OF THORACIC ONCOLOGY, 10, 9, S585, S585, 2015年09月, [査読有り]
    ELSEVIER SCIENCE INC, 英語, 研究発表ペーパー・要旨(国際会議)
  • 紙を利用した分析・診断チップ               
    真栄城正寿, 渡慶次学, 紙パルプ技術タイムス, 58, 37, 42, 2015年08月, [招待有り]
    日本語, 記事・総説・解説・論説等(商業誌、新聞、ウェブメディア)
  • 脂質ナノ粒子の粒径制御のためのマイクロ流体デバイス設計
    真栄城正寿, 藤島由佳, 佐藤悠介, 石田晃彦, 谷博文, 原島秀吉, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 32nd, 2015年
  • バイオミメティック・ケミストリーによる単一細胞からのRNA抽出法の創成
    岡本行広, 大川智生, 小野島大介, 湯川博, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 95th, 1, 2015年
  • バイオミメティック・ケミストリーによる単一細胞からのRNA抽出法の創成
    岡本行広, 大川智生, 小野島大介, 湯川博, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 95th, 3, 2015年
  • バイオミメティックな手法によるマイクロチップ表面の改質および分離への応用
    岡本行広, 渡慶次学, 馬場嘉信, 分析化学討論会講演要旨集, 75th, 2015年
  • 肺癌体細胞遺伝子変異の免疫学的診断デバイスの開発
    笠間敏博, 笠間敏博, 長谷哲成, 石川広弥, 石川広弥, 與語直之, 近藤征史, 加地範匡, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 渡慶次学, 長谷川好規, 長谷川好規, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 32nd, 2015年
  • Immuno-wallマイクロ免疫診断チップによるIDH1遺伝子変異の迅速診断
    山道茜, 山道茜, 大岡史治, 笠間敏博, 加藤幸成, 栗本路弘, 近藤五郎, 青木恒介, 鈴木啓道, 本村和也, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 鈴木秀謙, 若林俊彦, 夏目敦至, 日本脳腫瘍学会プログラム・抄録集, 33rd, 2015年
  • Immuno-wall lab-on-chip companion diagnostic devices for rapid and low-cost detection of mutant epidermal growth factor receptors (EGFR) from cytological samples in lung cancer patients
    T. Kasama, T. Hase, N. Nishiwaki, N. Yogo, M. Sato, M. Kondo, N. Kaji, M. Tokeshi, Y. Hasegawa, Y. Baba, MicroTAS 2015 - 19th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 925, 927, 2015年, [査読有り]
    © 15CBMS-0001. In the present study, we propose immuno-wall lab-on-a-chip companion diagnostic devices for epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) such as erlotinib and gefitinib. The lysates of cytological samples including pleural effusion in lung cancer patients were successfully analyzed within 20 minutes. This is the first experiment demonstrating the detection of mutated EGFRs in the pleural effusion by microdevices. Our devices have a great potential to become the next generation companion diagnostic devices which overcome the problems of currently available methods., 英語, 速報,短報,研究ノート等(学術雑誌)
  • Label-free detection of extracellular vesicles for cancer diagnosis
    Taiga Ajiri, Takao Yasui, Akihiko Ishida, Hirofumi Tani, Yoshinobu Baba, Manabu Tokeshi, MicroTAS 2015 - 19th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1789, 1791, 2015年, [査読有り]
    © 15CBMS-0001. We have developed a label-free detection method of biomolecules using nanostructures [1]. The principle of this method is based on intensity changes of diffracted light derived from the nanostructures. This method is very simple and useful for label-free detection of biomolecules, but further improvement in sensitivity was necessary to apply it to clinical applications. In this paper, we optimized optical system and device design to improve the sensitivity, and applied it to measure extracellular vesicles for cancer diagnosis. These results showed that our method had a potential to be a first screening method for cancer diagnosis., 英語, 速報,短報,研究ノート等(学術雑誌)
  • Microfluidic approach for production of lipid nanoparticles-based nano medicine
    M. Maeki, T. Saito, Y. Node, Y. Sato, T. Yasui, N. Kaji, A. Ishida, H. Tani, Y. Baba, H. Harashima, M. Tokeshi, MicroTAS 2015 - 19th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 838, 840, 2015年, [査読有り]
    © 15CBMS-0001. This paper described a simple preparation method for small-size and monodispersed lipid nanoparticles (LNPs) by using microfluidic devices. The fundamental role and importance of chaotic micromixer in the microfluidic device was demonstrated. The suitable cycle number of chaotic micromixer was confirmed for precise controlling LNPs size with narrow distribution under the any flow rate conditions. In addition, LNPs containing siRNA was synthesized for evaluation of penetration efficiency via in vivo experiment. The PEGylated LNPs containing siRNA with a diameter of 30 nm could penetrate to the mouse parenchymal liver cells rather than the LNPs with a diameter of 50 nm., 英語, 記事・総説・解説・論説等(国際会議プロシーディングズ)
  • 2014年ノーベル化学賞 超解像蛍光顕微鏡の開発
    加地 範匡, 渡慶次 学, 馬場 嘉信, 現代化学 = Chemistry today, 525, 31, 34, 2014年12月
    東京化学同人, 日本語
  • 超解像蛍光顕微鏡の開発               
    加地範匡, 渡慶次学, 馬場嘉信, 現代化学, 12, 31-34, 2014年12月01日
    日本語, 速報,短報,研究ノート等(学術雑誌)
  • LCD-CCD Synchronization Detection for Fluorescece Polarization Immunoassay               
    Osamu Wakao, Yusaku Fujii, Akihiko Ishida, Hirofumi Tani, Akihide Hibara, Manabu Tokeshi, Proceedings of the Micro TAS 2014 Symposium, 2271, 2273, 2014年10月, [査読有り]
    英語, 記事・総説・解説・論説等(国際会議プロシーディングズ)
  • Crystal Habit Modification of Protein by Using Microfluidic Chip
    Masatoshi Maeki, Ashtamurthy P. Pawate, Keiichi Watanabe, Manabu Tokeshi, Paul J. Kenis, Masaya Miyazaki, Proceedings of the Micro TAS 2014 Symposium, 1083, 1085, 2014年10月, [査読有り]
    We demonstrate a novel method for controlling morphology and aggregation of protein crystals by focusing on the depth of microchannel. The microfluidic chip with normally closed valves was fabricated for crystallization experiments and in-situ X-ray analysis. Crystal habit of protein was dramatically changed by depth of crystallization chamber. We found the potential of microfluidic chip for controlling crystal habit as well as aggregation of protein crystals., 英語, 記事・総説・解説・論説等(国際会議プロシーディングズ)
  • 細胞表層改質による単一細胞抽出法の創成               
    岡本 行広, 大川 智生, 小野島 大介, 湯川 博, 渡慶次 学, 馬場 嘉信, 日本分析化学会講演要旨集, 63年会, 37, 37, 2014年09月
    (公社)日本分析化学会, 日本語
  • マイクロリアクタを用いたカリックスアレーン誘導体による希少金属分離プロセスの最適化
    RAO Sathuluri. R., 真栄城正寿, 真栄城正寿, KIM Jee Young, 上田祐生, 大渡啓介, 渡慶次学, 宮崎真佐也, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 30th, 2014年
  • マイクロ流体デバイスによるタンパク質の結晶化制御技術
    真栄城正寿, 真栄城正寿, PAWATE Ashtamurthy S., 渡邉啓一, 渡慶次学, KENIS Paul J. A., 宮崎真佐也, 日本結晶学会年会講演要旨集, 2014, 2014年
  • マイクロ流路を用いたタンパク質結晶の晶癖制御
    真栄城正寿, 真栄城正寿, 真栄城正寿, PAWATE Ashtamurthy, 渡邉啓一, 渡慶次学, KENIS Paul J. A., 宮崎真佐也, 宮崎真佐也, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 29th, 2014年
  • 簡便な稀少細胞同定・回収方法の創成
    岡本行広, 湯川博, 渡慶次学, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 94th, 1, 2014年
  • 無動力駆動抽出法の創成
    岡本行広, 湯川博, 渡慶次学, 馬場嘉信, 馬場嘉信, 分析化学討論会講演要旨集, 74th, 2014年
  • 無動力抽出法の創成
    岡本行広, 湯川博, 渡慶次学, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 94th, 2, 2014年
  • ナノバイオデバイスを用いたmicro-RNAの高速抽出
    WU Qiong, WU Qiong, 安井隆雄, 安井隆雄, SAKON Rahong, 長島一樹, 柳田剛, 金井真樹, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 川合知二, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 94th, 2, 2014年
  • ナノ構造体を用いた無標識DNAの高感度検出
    阿尻大雅, 安井隆雄, 安井隆雄, 石田晃彦, 谷博文, 馬場嘉信, 馬場嘉信, 渡慶次学, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 29th, 2014年
  • 治療標的としての上皮成長因子受容体遺伝子変異の特異的検出
    笠間敏博, 笠間敏博, 長谷哲成, 近藤征史, 加地範匡, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 渡慶次学, 長谷川好規, 長谷川好規, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 30th, 2014年
  • マイクロ流路内におけるリポソーム形成メカニズムの考察
    齋藤竜亮, 真栄城正寿, 安井隆雄, 安井隆雄, 石田晃彦, 谷博文, 馬場嘉信, 馬場嘉信, 渡慶次学, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 30th, 2014年
  • ナノ構造体の光回折を利用した高感度無標識検出法の開発
    阿尻大雅, 安井隆雄, 安井隆雄, 石田晃彦, 谷博文, 馬場嘉信, 馬場嘉信, 渡慶次学, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 30th, 2014年
  • イムノウォールデバイスによる疾病マーカーのマルチプレックスアッセイ
    西脇奈菜子, 笠間敏博, 石田晃彦, 谷博文, 馬場嘉信, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 30th, 2014年
  • オンチップ制限酵素反応における遭遇複合体形成過程の1分子解析
    小野島大介, 加地範匡, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 94th, 2, 2014年
  • 小型・低コストな疾病マーカー定量分析装置の開発
    笠間敏博, 笠間敏博, 長谷川寛, 近藤治靖, 小澤勉, 加地範匡, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 94th, 2, 2014年
  • 迅速・簡便疾患診断のためのイムノピラーデバイスの形状最適化
    笠間敏博, 笠間敏博, 長谷川寛, 長谷川寛, 近藤治靖, 近藤治靖, 小澤勉, 小澤勉, 加地範匡, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 29th, 2014年
  • ナノ構造体を利用した生体由来物質の高感度無標識測定法の開発
    渡慶次 学, 旭硝子財団助成研究成果報告, 1, 6, 2014年
    旭硝子財団, 日本語
  • On-Chip Analysis of Intermittent Molecular Encounters in Nuclease Digestion of Specific DNA Sequence
    Daisuke Onoshima, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, BIOPHYSICAL JOURNAL, 106, 2, 699A, 699A, 2014年01月
    CELL PRESS, 英語, 研究発表ペーパー・要旨(国際会議)
  • Development of immuno-wall devices and a mobile fluorescence reader for on-site sample-to-answer immunoassay
    Toshihiro Kasama, Yutaka Hasegawa, Haruyasu Kondo, Tsutomu Ozawa, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014, 935, 937, 2014年, [査読有り]
    © 14CBMS. We have developed a novel immunoassay device which has a long and thin wall structure inside a microchannel, hence the name 'immuno-wall device'. Unreacted antigens and antibodies were completely removed by just immersing the device in a washing buffer for 1 minute. The long structure also allowed us to analyze fluorescence intensity by using inexpensive desktop fluorescence reader ($6,000) instead of expensive fluorescence microscopes. By using the immuno-wall devices and the fluorescence reader, the high-sensitivity C-reactive protein assays were performed with sample-in-answer-out in 15 minutes., 英語, 記事・総説・解説・論説等(国際会議プロシーディングズ)
  • A millisecond micro-RNA extraction technique for nanopore-based nucleic acid sequencing
    Qiong Wu, Takao Yasui, Sakon Rahong, Takeshi Yanagida, Masaki Kanai, Noritada Kaji, Manabu Tokeshi, Kazuki Nagashima, Tomoji Kawai, Yoshinobu Baba, 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014, 233, 235, 2014年, [査読有り]
    © 14CBMS. A ms(millisecond) miRNA(micro RNA) extraction from a mixture of total RNA and genomic DNA was successfully achieved by the combination of nanopillar and nanoslit structures inside a microchannel. This ultra-fast miRNA extraction technique especially useful for exosome-derived miRNA sequencing by nanopore-based RNA sequencer since exosomes contain miRNA and mRNA., 英語, 記事・総説・解説・論説等(国際会議プロシーディングズ)
  • 量子スイッチング効果による脳腫瘍細胞の高感度検出手法の構築
    湯川 博, 塚本 涼子, 岡本 行広, 水野 正明, 加地 範匡, 渡慶次 学, 馬場 嘉信, Organ Biology, 20, 3, 105, 105, 2013年10月
    (一社)日本臓器保存生物医学会, 日本語
  • ナノワイヤデバイスを用いた細胞破砕               
    安井 隆雄, 伊藤 聡, 柳田 剛, 加地 範匡, Yong He, Rahong Sakon, 金井 真樹, 長島 一樹, 渡慶次 学, 川合 知二, 馬場 嘉信, 日本分析化学会講演要旨集, 62年会, 145, 145, 2013年08月
    (公社)日本分析化学会, 日本語
  • Application of IgY to ELISA, LFDs, and immunopillar chips for detecting staphylococcal enterotoxins in milk and dairy products
    W. Jin, K. Yamada, M. Ikami, N. Kaji, M. Tokeshi, Y. Atsumi, M. Mizutani, A. Murai, A. Okamoto, T. Namikawa, Y. Baba, M. Ohta, INTERNATIONAL JOURNAL OF ANTIMICROBIAL AGENTS, 42, S46, S47, 2013年06月
    ELSEVIER SCIENCE BV, 英語, 研究発表ペーパー・要旨(国際会議)
  • Nano Packagingが拓く次世代核酸医療
    松尾保隆, 加地範匡, 畠山浩人, 渡慶次学, 小暮健太朗, 馬場嘉信, 原島秀吉, 表面, 51, 5, 227-240, 240, 2013年05月, [査読有り]
    広信社, 日本語, 速報,短報,研究ノート等(学術雑誌)
  • ICP-MS連結マイクロ流路による1細胞レベルでの金属元素検出システムの開発
    宮崎義之, 安井隆雄, 宮下振一, 稲垣和三, 加地範匡, 梅村知也, 渡慶次学, 馬場嘉信, 化学とマイクロ・ナノシステム研究会誌,, 12, 1, 16-21, 2013年03月29日
    日本語, 速報,短報,研究ノート等(学術雑誌)
  • 小型・高感度マイクロチップ用蛍光検出システムの構築と評価
    長谷川寛, 長谷川寛, 松本浩幸, 笠間敏博, 笠間敏博, 加地範匡, 加地範匡, 加地範匡, 近藤治靖, 近藤治靖, 小澤勉, 小澤勉, 渡慶次学, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 93rd, 1, 2013年
  • 超高性能無動力in situ抽出法の創成
    岡本行広, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 93rd, 1, 2013年
  • 細胞の表層改質を利用したマイクロデバイスによる単一細胞解析
    日比野理人, 岡本行広, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 93rd, 2, 2013年
  • ナノ構造体を用いたDNA増幅のリアルタイム無標識検出
    安井隆雄, 安井隆雄, 小川謙亮, 小川謙亮, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 堀池靖浩, NILSSON Mats, 馬場嘉信, 馬場嘉信, 馬場嘉信, 分析化学討論会講演要旨集, 73rd, 2013年
  • リアルタイムDNA増幅の高感度無標識検出法
    小川謙亮, 小川謙亮, 安井隆雄, 安井隆雄, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 堀池靖浩, NILSSON Mats, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 93rd, 2, 2013年
  • 血中希少循環腫瘍細胞の簡便・安価な非標識検出法および回収法の創成
    岡本行広, 長谷哲成, 渡慶次学, 長谷川好規, 馬場嘉信, 日本化学会講演予稿集, 93rd, 1, 2013年
  • 単一細胞解析のためのバイオミメティック細胞表層改質法の創成
    岡本行広, 渡慶次学, 馬場嘉信, 馬場嘉信, 分析化学討論会講演要旨集, 73rd, 2013年
  • 遺伝子治療用ナノ構造体精製のためのフリーフロー電気泳動マイクロデバイスの開発
    重中大輔, 鵜川真美, 加地範匡, 渡慶次学, 秋田英万, 原島秀吉, 馬場嘉信, 日本化学会講演予稿集, 93rd, 2, 2013年
  • ナノバイオデバイスを用いた生体分子の超高速分離
    WU Qiong, WU Qiong, 安井隆雄, 安井隆雄, SAKON Rahong, 長島一樹, 柳田剛, 金井真樹, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 川合知二, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 93rd, 2, 2013年
  • 細胞の物理的破砕のためのナノワイヤデバイスの開発
    安井隆雄, 安井隆雄, 伊藤聡, 伊藤聡, 柳田剛, 加地範匡, 加地範匡, HE Yong, RAHONG Sakon, 金井真樹, 長島一樹, 渡慶次学, 渡慶次学, 川合知二, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 27th, 2013年
  • 音を利用したマイクロ流体デバイスへの小型電力供給システム
    内藤豊裕, 内藤豊裕, 内藤豊裕, 加地範匡, 加地範匡, LE GAC Severine, 安井隆雄, 安井隆雄, 渡慶次学, 渡慶次学, VAN DEN BERG Albert, 久保拓也, 大塚浩二, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 27th, 2013年
  • ベッドサイド診断を目的としたイムノピラーデバイスの可搬型検出器の開発
    笠間敏博, 笠間敏博, 長谷川寛, 長谷川寛, 松本浩幸, 近藤治靖, 近藤治靖, 小澤勉, 小澤勉, 加地範匡, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 27th, 2013年
  • マイクロ流体デバイスを用いるDDSナノキャリアの作製
    齋藤竜亮, 安井隆雄, 安井隆雄, 石田晃彦, 谷博文, 加地範匡, 加地範匡, 馬場嘉信, 馬場嘉信, 渡慶次学, 渡慶次学, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 28th, 2013年
  • 単一細胞解析のためのバイオミメティック細胞表層改質法の創成
    岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 高分子学会予稿集(CD-ROM), 62, 1, 2013年
  • 積層厚膜SU-8ドライフィルムレジストで成形した深型流路を持つ吸光測定用マイクロフローセル
    小野島大介, WANG Jun, 安藝理彦, 有永健児, 加地範匡, 渡慶次学, 藤田省三, 横山直樹, 馬場嘉信, 日本化学会講演予稿集, 93rd, 2, 2013年
  • 自己組織化ナノワイヤ構造体を利用したDNAの分離解析
    安井隆雄, 安井隆雄, SAKON Rahong, 柳田剛, 加地範匡, 加地範匡, 金井真樹, 長島一樹, 渡慶次学, 渡慶次学, 川合知二, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 93rd, 2, 2013年
  • イムノピラーデバイスを用いたその場診断システム
    笠間敏博, 加地範匡, 馬場嘉信, 長谷川寛, 松本浩幸, 近藤治靖, 小澤勉, 渡慶次学, 電気学会バイオ・マイクロシステム研究会資料, BMS-13, 35-47, 2013年
  • 高感度CRP分析のための小型診断システム
    笠間敏博, 笠間敏博, 長谷川寛, 長谷川寛, 近藤治靖, 近藤治靖, 小澤勉, 小澤勉, 加地範匡, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 28th, 2013年
  • イムノピラーチップの高性能化
    西脇奈菜子, 石田晃彦, 谷博文, 笠間敏博, 笠間敏博, 馬場嘉信, 馬場嘉信, 馬場嘉信, 渡慶次学, 渡慶次学, 渡慶次学, 化学とマイクロ・ナノシステム学会研究会講演要旨集, 27th, 2013年
  • High-speed micro-RNA isolation from DNA fragments by nanopiller array chip
    Qiong Wu, Takao Yasui, Sakon Rahong, Takeshi Yanagida, Masaki Kanai, Noritada Kaji, Manabu Tokeshi, Kazuki Nagashima, Tomoji Kawai, Yoshinobu Baba, 17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013, 2, 1206, 1208, 2013年, [査読有り]
    A novel nanopillar chip, which combines pillar structures (nanopillars) and dammed structures (nanoslits) at the nanometer scale inside a microchannel, was fabricated and applied to micro-RNA isolation from a mixture of nucleic acids. Electrophoretic behaviors of micro-RNA and DNA fragments in the nanopillar chip were carefully investigated and the isolation condition was optimized for the mixture of 10-kbp, lambda (48.5-kbp) and T4 DNA (165.5-kbp)., 英語, 記事・総説・解説・論説等(国際会議プロシーディングズ)
  • High throughput purification devices for in vivo applications of gene-delivery multifunctional envelope-type nanodevices
    Noritada Kaji, Daisuke Shigenaka, Masami Ukawa, Manabu Tokeshi, Hidetaka Akita, Hideyoshi Harashima, Yoshinobu Baba, 17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013, 2, 1170, 1172, 2013年, [査読有り]
    We developed microfluidic continuous purification devices based on free-flow electrophoresis for gene-delivery multifunctional envelope-type nanodevices (MEND) which consists of DNA core and phospholipid bilayer envelope. Various impurities, such as DNA, DNA-peptide complex, and liposomes, produced during the fabrication process were removed in an efficient manner and over 75% collection of the input plasmid DNA which corresponds to purified MEND was achieved., 英語, 記事・総説・解説・論説等(国際会議プロシーディングズ)
  • Development of 3RD generation immuno-pillar device for high sensitive detection of disease markers
    N. Nishiwaki, T. Kasama, A. Ishida, H. Tani, Y. Baba, M. Tokeshi, 17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013, 2, 1164, 1166, 2013年, [査読有り]
    We previously developed immuno-pillar devices for rapid and easy-to-use immunoassay [1-3]. However, improvement in the detection sensitivity (nM-pM) has still remained as a problem toward the screening test for disease markers with low cut-off values. We report here a third-generation immuno-pillar device in which the primary antibodies are covalently bounded to polymers on microbeads. By using this device we achieved pM-fM detection sensitivity of C-reactive protein (CRP) spiked in human serum. Moreover, we demonstrated that the device has long-term stability. From these results, it was proved that the third-generation device has capability required for practical use., 英語, 記事・総説・解説・論説等(国際会議プロシーディングズ)
  • Label-free detection and quantification of real-time DNA amplification using one-dimensional photonic crystal
    Takao Yasui, Kensuke Ogawa, Noritada Kaji, Mats Nilsson, Manabu Tokeshi, Yasuhiro Horiike, Yoshinobu Baba, 17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013, 2, 1123, 1125, 2013年, [査読有り]
    We could achieve label-free detection and quantification of real-time DNA amplification using a one-dimensional (1D) photonic crystal embedded in microchannels. Our method could be applicable to ultra-highly sensitive detection of human papillomavirus (HPV) and tubercle bacillus (TB) from 1 zmol to 1 amol. The limit of detection (LOD) of TB sequence in our system was around 500 ymol., 英語, 記事・総説・解説・論説等(国際会議プロシーディングズ)
  • Microfluidic single-molecule nuclease digestion reveals rate-enhancing off-and-on molecular encountering function for site-specific DNA break
    D. Onoshima, N. Kaji, M. Tokeshi, Y. Baba, 17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013, 2, 820, 822, 2013年, [査読有り]
    An intermittent molecular encounter leading to a site-specific DNA-break was unveiled under a limited protein's sliding-free condition. It reflects a transient molecular action by which the reaction rate and efficiency of restriction enzyme in bacterial cells is enhanced. This was experimentally verified for the first time in the world by using our microfluidic device., 英語, 記事・総説・解説・論説等(国際会議プロシーディングズ)
  • 連載 超解像顕微鏡の世界:波長の壁を超えて見る(1) 超解像顕微鏡とは:Abbeの法則への挑戦               
    加地範匡, 渡慶次学, 馬場嘉信, 現代化学, 502, 1, 50-54, 2012年12月
    日本語, 記事・総説・解説・論説等(学術雑誌)
  • Portable Liquid Chromatography System Based on Battery-Powered Electroosmotic Pump and Microchip with Packed Column and Electrochemical Detector               
    Akihiko Ishida, Takehiro Fujimoto, Satoshi Yokokawa, Hirofumi Tani, Manabu Tokeshi, Ichiro Yanagisawa, Proceedings of the MicroTAS 2012 Symposium, 1183, 1185, 2012年10月, [査読有り]
    英語, 研究発表ペーパー・要旨(国際会議)
  • On-Chip Bioluminescence Assay of ATP and Kinases Using Immobilized Firefly Luciferase in Three-Dimensional Microfluidic Chip               
    Hirofumi Tani, Atsuki Morisaki, Akihiko Ishida, Manabu Tokeshi, Proceedings of the MicroTAS 2012 Symposium, 1618, 1620, 2012年10月, [査読有り]
    英語, 研究発表ペーパー・要旨(国際会議)
  • エピジェネティクス解析のための一分子DNAメチル化検出技術の開発               
    岡本 行広, 佐野 竜輝, 加地 範匡, 渡慶次 学, 馬場 嘉信, 日本分析化学会講演要旨集, 61年会, 68, 68, 2012年09月
    (公社)日本分析化学会, 日本語
  • ナノワイヤデバイスによる生体分子解析               
    大塚 康平, 安井 隆雄, Rahong Sakon, 柳田 剛, 加地 範匡, 金井 真樹, 長島 一樹, 渡慶次 学, 谷口 正輝, 川合 知二, 馬場 嘉信, 日本分析化学会講演要旨集, 61年会, 191, 191, 2012年09月
    (公社)日本分析化学会, 日本語
  • マイクロ流体チップによる多機能性エンベロープ型ナノ構造体の作製               
    加地 範匡, 北添 雄眞, 重中 大輔, 小暮 健太朗, 秋田 英万, 原島 秀吉, 渡慶次 学, 馬場 嘉信, 日本DDS学会学術集会プログラム予稿集, 28回, 182, 182, 2012年06月
    日本DDS学会, 日本語
  • ナノ構造体を用いたリアルタイムDNA増幅の無標識検出法
    小川謙亮, 小川謙亮, 安井隆雄, 安井隆雄, 加地範匡, 加地範匡, 岡本行広, 渡慶次学, 渡慶次学, 堀池靖浩, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 92nd, 2, 2012年
  • フリーフロー電気泳動法を用いた遺伝子治療用ナノデバイスの精製
    重中大輔, 鵜川真美, 加地範匡, 岡本行広, 渡慶次学, 秋田英万, 原島秀吉, 馬場嘉信, 日本化学会講演予稿集, 92nd, 2, 2012年
  • ナノピラー境界面でのDNAトラッピング現象を用いたDNA分離
    本山高貴, 安井隆雄, 加地範匡, 岡本行広, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 92nd, 2, 2012年
  • PMMA製マイクロピラーアレイデバイスによる血球分離
    伊藤聡, 伊藤聡, 安井隆雄, 安井隆雄, 岡本行広, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 25th, 2012年
  • マイクロデバイスとICP-MSを組み合わせた単一細胞解析法の開発
    宮崎義之, 宮崎義之, 安井隆雄, 安井隆雄, 稲垣和三, 岡本行広, 加地範匡, 加地範匡, 梅村知也, 渡慶次学, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 92nd, 1, 2012年
  • ナノワイヤデバイスを用いた生体分子の分離
    WU Qiong, WU Qiong, 本山高貴, 本山高貴, 安井隆雄, 安井隆雄, SAKON Rahong, 柳田剛, 金井真樹, 岡本行広, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 長島一樹, 川合知二, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 92nd, 1, 2012年
  • ナノ構造体による回折現象を用いたDNAの無標識検出
    安井隆雄, 小川謙亮, 加地範匡, 岡本行広, 渡慶次学, 堀池靖浩, 馬場嘉信, 日本化学会講演予稿集, 92nd, 2, 2012年
  • ナノ構造体を用いたDNA無標識検出法
    安井隆雄, 安井隆雄, 小川謙亮, 小川謙亮, 加地範匡, 加地範匡, 岡本行広, 渡慶次学, 渡慶次学, 渡慶次学, 堀池靖浩, 馬場嘉信, 馬場嘉信, 馬場嘉信, 分析化学討論会講演要旨集, 72nd, 2012年
  • ナノピラーとナノスリットを組み合わせた新規ナノ構造体による生体分子の超高速分離
    呉瓊, 呉瓊, 安井隆雄, 安井隆雄, RAHONG Sakon, 柳田剛, 金井真樹, 長島一樹, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 川合知二, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 25th, 2012年
  • 迅速・簡便なエピジェネティクス解析のためのマイクロ流体デバイスを利用した1分子DNAメチル化検出
    佐野竜輝, 小野島大介, 岡本行広, 加地範匡, 近藤豊, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 92nd, 2, 2012年
  • マイクロ血球分離デバイスの開発
    伊藤聡, 伊藤聡, 安井隆雄, 安井隆雄, 岡本行広, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 92nd, 1, 2012年
  • 1分子DNAのマイクロ流体制御下における酵素分解反応の運動学的解析
    小野島大介, 加地範匡, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 92nd, 2, 2012年
  • 浮遊細胞培養のための環流培養チップの開発
    内藤豊裕, 内藤豊裕, 加地範匡, 加地範匡, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム, 11, 1, 2012年
  • ミドリムシによる細胞分離法の創成
    岡本行広, 中北行紀, 佐野貴大, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 92nd, 3, 2012年
  • 高集積化マイクロ化学チップのための自律駆動型マイクロバルブの開発
    内藤豊裕, 内藤豊裕, 加地範匡, 加地範匡, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 92nd, 2, 2012年
  • 機能性ユーグレナの創成および分離手法への応用
    岡本行広, 中北行紀, 佐野貴大, 加地範匡, 加地範匡, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 分析化学討論会講演要旨集, 72nd, 2012年
  • ナノワイヤデバイスによる1分子DNA解析
    本山高貴, 本山高貴, 安井隆雄, 安井隆雄, RAHONG Sakon, 柳田剛, 加地範匡, 加地範匡, 金井真樹, 長島一樹, 岡本行広, 渡慶次学, 渡慶次学, 渡慶次学, 川合知二, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 25th, 2012年
  • ICP-MSを用いた単一がん細胞内金属元素量解析のための微粒子挙動制御デバイスの作製
    宮崎義之, 宮崎義之, 安井隆雄, 安井隆雄, 稲垣和三, 岡本行広, 加地範匡, 加地範匡, 梅村知也, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 25th, 2012年
  • ハイスループット血漿分離のための渦巻き型マイクロチャネル
    森川純平, 森川純平, 加地範匡, 加地範匡, 岡本行広, 渡慶次学, 渡慶次学, 坪田一男, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 92nd, 2, 2012年
  • バイオミメティックプロセスを利用した単一細胞解析手法の開発
    日比野理人, 岡本行広, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 92nd, 2, 2012年
  • パイこね変換に基づく量産対応・高速ミキサの開発
    尾本悠輔, 加藤大香士, 鈴木教和, 安井隆雄, 大里恵子, 加地範匡, 渡慶次学, 馬場嘉信, 酒井康彦, 社本英二, 日本機械学会論文集 B編(Web), 78, 788, 2012年
  • カーボンナノウォールの細胞培養基材への応用
    岡本行広, 久保和稔, 久保和稔, 渡邊均, 近藤博基, 渡慶次学, 渡慶次学, 堀勝, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 92nd, 3, 2012年
  • 量子ドットを用いた腫瘍細胞イメージング
    中尾早織, 中尾早織, PARK Yeon-Su, 岡本行広, 加地範匡, 加地範匡, 水野正明, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 92nd, 2, 2012年
  • イムノピラーチップを用いた尿中の糖尿病性腎症マーカーの高感度・高速検出
    笠間敏博, 笠間敏博, SUN Miaomiao, 秋山真一, 加地範匡, 加地範匡, 湯澤由紀夫, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 92nd, 2, 2012年
  • マイクロチップを用いた分析手法のための蛍光検出システムの構築と評価
    長谷川寛, 長谷川寛, 長谷川寛, 松本浩幸, 笠間敏博, 笠間敏博, 加地範匡, 加地範匡, 加地範匡, 近藤治靖, 近藤治靖, 小澤勉, 小澤勉, 渡慶次学, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, キャピラリー電気泳動シンポジウム講演要旨集, 32nd, 2012年
  • On-Chip Electric Power Generation System from Sound of Portable Music Players and Smartphones Toward Portable μTAS
    Toyohiro Naito, Noritada Kaji, Séverine Le Gac, Manabu Tokeshi, Albert van den Berg, Yoshinobu Baba, Proceedings of the MicroTAS 2012 Symposium, 1852, 1854, 2012年, [査読有り]
    This paper demonstrates electric generation from sound to minimize and integrate microfluidic systems for point of care testing or in-situ analysis. In this work, 5.4 volts and 50 mW DC was generated from sound through an earphone cable, which is a versatile system and able to actuate small size and low power consumption devices like an electro osmotic pump., 英語, 研究発表ペーパー・要旨(国際会議)
  • Identification of single molecular DNA methylation points by microfluidic DNA molecule stretching and quantum dot detection
    Yukihiro Okamoto, Tatsuki Sano, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012, 1939, 1941, 2012年, [査読有り]
    We report a rapid and simple epigenetic analysis based on microfluidic single DNA molecular methylation detection. We developed a microfluidic device to stretch a single DNA molecule and subsequent detection of a methylated DNA base by quantum dot (QD)-immobilized methyl binding domain (MBD) protein. A QD-MBD complex specifically bound to a methylated base of stretched DNA and was detected by a total internal reflection fluorescence microscope (TIRFM). Our method enables us to detect a number of methylation site and identify the methylated positions simultaneously in the simple and rapid manner compared with the conventional methods., 英語, 研究発表ペーパー・要旨(国際会議)
  • Label-free detection of real-time DNA amplification using nanowall array structures
    Kensuke Ogawa, Takao Yasui, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yasuhiro Horiike, Mats Nilsson, Yoshinobu Baba, Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012, 25, 27, 2012年, [査読有り]
    We performed label-free detection of real-time DNA amplification inside nanowall array structures, which have never realized in other techniques. The label-free and real-time detection of linear amplification of DNA molecules by circle-to-circle amplification (C2CA) was achieved because our label-free detection system could recognize the length of DNA molecules., 英語, 研究発表ペーパー・要旨(国際会議)
  • Single DNA manipulation in sublithographic nanowire array chips
    Takao Yasui, Sakon Rahong, Takeshi Yanagida, Noritada Kaji, Masaki Kanai, Kentaro Doi, Manabu Tokeshi, Satovuki Kawano, Tomoji Kawai, Yoshinobu Baba, Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012, 228, 230, 2012年, [査読有り]
    We show the feasibility of self-assembled nanowire post-array embedded in niicrochamiels to manipulate the dynamics of single long T4-DNA molecule. DNA molecules in the spot-array of nanowires are fully elongated, and interestingly they exhibit not only the dynamics inside nanopillar array but also that inside gel matrix., 英語, 研究発表ペーパー・要旨(国際会議)
  • Plasma separation from human blood using spiral microchannels for dry eye treatment
    Jumpei Morikawa, Takao Yasui, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Kazuo Tsubota, Yoshinobu Baba, Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012, 464, 466, 2012年, [査読有り]
    We demonstrated that spiral microchannels could efficiently separate plasma from whole human blood toward autologous serum eye drop, which provides benefits for all dry eye patients. The optimized spiral microchannels realized 100% separation of 10 μm particles and over 90% separation of blood samples., 英語, 研究発表ペーパー・要旨(国際会議)
  • Sub-millisecond separation of DNA and micro-RNA by nanopillar array chips
    Qiong Wu, Koki Motoyama, Takao Yasui, Sakon Rahong, Takeshi Yanagida, Masaki Kanai, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Kazuki Nagashima, Tomoji Kawai, Yoshinobu Baba, Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012, 599, 601, 2012年, [査読有り]
    In this study, we fabricated a novel nanostructure that combined the pillar structures (nanopillar) and dammed structures (nanoslit) in nanometer-scale inside microchannels to realize ultra-fast separation. Nanopilliar chips were fabricated by using electron-beam lithography, photolithography and plasma etching. We used the nanopillar chip to realize ultra-fast separation of T4 DNA (165.5 kbp) and microRNA (22 b). By decreasing height down to 100 nm, we succeeded in separating DNA and microRNA in sub-milliseconds., 英語, 研究発表ペーパー・要旨(国際会議)
  • A highly efficient 3D micromixer fabricated by standard soft-lithography equipment
    Toyohiro Naito, Rerngchai Arayanarakool, Noritada Kaji, Séverine Le Gac, Manabu Tokeshi, Albert Van Den Berg, Yoshinobu Baba, Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012, 662, 664, 2012年, [査読有り]
    This paper reports a stereolithography-like 3D fabrication method based on soft-lithography techniques. It only requires standard equipment for photolithography, but it makes true 3D structures fabrication possible. We developed a rotating partition by this method in a microfluidic channel, which cannot be achieved by conventional soft-lithography, and demonstrated a prototyping three-dimensional flow mixer., 英語, 研究発表ペーパー・要旨(国際会議)
  • Detection of metallic elements in a single cancer cell using microfluidic devices coupled with ICP-MS
    Yoshiyuki Miyazaki, Takao Yasui, Kazumi Inagaki, Yukihiro Okamoto, Noritada Kaji, Tomonari Umemura, Manabu Tokeshi, Yoshinobu Baba, Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012, 767, 769, 2012年, [査読有り]
    This paper presents a new single cancer cell analysis technique to combine microfluidic devices with inductively coupled plasma-mass spectrometry (ICP-MS). Inherent signals of cancer cells were quantitatively evaluated by launching the cells into ICP-MS via the microfluidic devices., 英語, 研究発表ペーパー・要旨(国際会議)
  • Rapid urine-based clinical diagnosis of diabetic nephropathy with femto-molar sensitivity by immuno-pillar devices
    Miaomiao Sun, Toshihiro Kasama, Noritada Kaji, Shin Ichi Akiyama, Yukio Yuzawa, Seiichi Matsuo, Manabu Tokeshi, Yoshinobu Baba, Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012, 812, 814, 2012年, [査読有り]
    We have developed immuno-pillar devices for rapid and easy-to-use immunoassay, but to improve the speed of assay (5-10 min) and the detection sensitivity (nM-pM level) has still remained as major problems toward the clinical applications of immuno-pillar devices. We report here the second-generation immuno-pillar devices with faster assay within 2 min and pM-fM detection sensitivity. New devices enable us to apply them to the clinical trials for the detection of multiple biomarkers (monocyte chemotactic protein 1 (MCP-1), angiotensinogen (AGT), liver-type fatty acid binding protein (L-FABP)) of diabetic nephropathy in human urine without any pretreatments., 英語, 研究発表ペーパー・要旨(国際会議)
  • Microfluidic rare cancer cell collection with anti-EpCAM antibody modified euglena by phototaxis inside microchannels
    Yukihiro Okamoto, Yukinori Nakakita, Takahiro Sano, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012, 1108, 1110, 2012年, [査読有り]
    We develop a microfluidic cell separation method which combined microfluidic devices and multifunctional Euglena. Multifunctional Euglena for cell separation was successfully prepared by the surface modification of Euglena cell membrane and its performances were confirmed. Mutlifunctional Euglena in the inlet attached cells, migrated inside the microchannel by phototaxis towards the outlet chamber, and brought specific cells to the outlet. After moving to the outlet, cells in the outlet were detached from Euglena. Since it is based on the unique characters of Euglena, our method needs only simple device and can deal with small to large amount variety kinds of samples including cells., 英語, 研究発表ペーパー・要旨(国際会議)
  • Develpoement of novel circulating tumor cells separation and non-labeling detection by circulating tumor cells' specific properties
    Kouhei Ootsuka, Yukihiro Okamoto, Tetsunari Hase, Manabu Tokeshi, Noritada Kaji, Yoshinori Hasegawa, Yoshinobu Baba, Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012, 1123, 1125, 2012年, [査読有り]
    We developed non-labeling detection and easy separation method of circulating tumor cells (CTCs) based on CTCs' specific properties. Our developed method requires no special apparatus and tedious pretreatment before separation and detection of CTCs. In addition, our methods can also separate and detect epithelial cell adhesion molecule (EpCAM) negative CTCs, which cannot be attained by present methods. Therefore, our method would become accurate CTCs' analysis method and useful for point-of-care testing of CTCs., 英語, 研究発表ペーパー・要旨(国際会議)
  • Nanopillar parallel-array structure with DNA trapping and torque-assisted escape mode for DNA separation
    Takao Yasui, Koki Motoyama, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yasuhiro Horiike, Yoshinobu Baba, Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012, 1186, 1188, 2012年, [査読有り]
    We revealed that the nanopillar parallel-array structure has two modes for DNA separation; DNA trapping and torque-assisted escape mode. Single DNA molecule observation revealed that the separation of DNA molecules could be achieved by two modes in the wide range of DNA molecules; 166 kbp to 100 bp., 英語, 研究発表ペーパー・要旨(国際会議)
  • Fabrication of PMMA micropillars by reactive ion etching towards separation of white and red blood cells
    Satoru Ito, Takao Yasui, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012, 1234, 1236, 2012年, [査読有り]
    Fine, high aspect ratio, and smooth surface micropillars, which never realized by conventional hot-embossing fabrication method, were fabricated on poly(methyl methacrylate) (PMMA) substrates by reactive ion etching (RIE). The separation ability of PMMA micropillars for microbeads as pseudo erythrocytes and leukocytes are comparable to Si micropillars, while the features of PMMA are superior to Si in terms of disposability, cost, and surface treatment., 英語, 研究発表ペーパー・要旨(国際会議)
  • High throughput purification device for gene delivery multifunctional envelope-type nanodevice
    Daisuke Shigenaka, Masami Ukawa, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Hidetaka Akita, Hideyoshi Harashima, Yoshinobu Baba, Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012, 1546, 1548, 2012年, [査読有り]
    Multifunctional envelope-type nanodevices (MEND) developed by Harashima et al. is one of the novel non-viral DNA vectors expected as a safe gene delivery system. Our group has already attained fast and easy preparation of MEND by using the microfluidic device. However, purification of MEND should be performed in a high-throughput manner because prepared MEND contains impurities such as plasmid-cationic polymer complex. In this paper, we report a novel purification method for MEND by free flow electrophoresis based on microfluidic device, which purification principle is based on the zeta potential difference between MEND and impurities., 英語, 研究発表ペーパー・要旨(国際会議)
  • Graphene forest devices as cell scaffolds for stem cells
    Yukihiro Okamoto, Hitoshi Watanabe, Kazutoshi Kubo, Hiroki Kondo, Noritada Kaji, Manabu Tokeshi, Masaru Hori, Yoshinobu Baba, Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012, 1633, 1635, 2012年, [査読有り]
    We developed carbon nanowalls devices (CNWs), on which graphenes vertically stand in the nanometer spacing like "graphene forest", with different wettability. CNWs permitted cell adhesion and proliferation, and especially super hydrophobic CNWs enabled easy and less invasive cell collection. Furthermore, collagen coated CNWs successfully enhanced the differential ability of the human mesenchymal stem cells (hMSC) to osteoblast cells compared to collagen coated polystyrene culture dishes. Thus, CNWs have superior many properties as cells scaffolds and are expected to be useful for regenerative medicine., 英語, 研究発表ペーパー・要旨(国際会議)
  • ナノ構造体による回折現象を利用した無標識検出法
    安井隆雄, 加地範匡, 岡本行広, 渡慶次学, 堀池靖浩, 馬場嘉信, 化学とマイクロ・ナノシステム研究会誌,, 10, 2, 22-23, 2011年11月
    日本語, 速報,短報,研究ノート等(学術雑誌)
  • Electroosmotic Flow in Nanopillar Chips               
    Takao Yasui, Noritada Kaji, M. Reza Mohamadi, Yukihiro Okamoto, Manabu Tokeshi, Yasuhiro Horiike, Yoshinobu Baba, ACS Nano, 5, 10, 7775-80, 2011年10月25日, [査読有り]
    英語, 速報,短報,研究ノート等(学術雑誌)
  • 急性肝不全マウスにおける移植幹細胞のIn vivoイメージング               
    湯川 博, 渡辺 将生, 宮本 義孝, 岡本 行広, 加地 範匡, 渡慶次 学, 野口 洋文, 馬場 嘉信, 林 衆治, JSMI Report, 4, 2, 57, 57, 2011年05月
    日本分子イメージング学会, 日本語
  • 急性肝不全マウスにおける移植幹細胞のIn vivoイメージング               
    湯川 博, 渡辺 将生, 宮本 義孝, 岡本 行広, 加地 範匡, 渡慶次 学, 野口 洋文, 馬場 嘉信, 林 衆治, JSMI Report, 4, 2, 167, 167, 2011年05月
    日本分子イメージング学会, 日本語
  • ナノ構造体上での幹細胞挙動の観察
    久保和稔, 岡本行広, 山本雅哉, 加地範匡, 渡慶次学, 田畑泰彦, 馬場嘉信, 日本化学会講演予稿集, 91st, 3, 716, 2011年03月11日
    日本語
  • Tracking Degradations of Single DNA and Protein Molecules in Fluid               
    D. Onoshima, N. Kaji, M. Tokeshi, Y. Baba, Biophysical Society 55th Annual Meeting, 100, 3, 151a-152a, 2011年03月, [査読有り]
    英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • 量子ドットによる幹細胞のin vivoイメージング               
    渡辺将生, 湯川博, 鏡味幸真, 加地範匡, 宮本義孝, 岡本行広, 渡慶次学, 林衆治, 馬場嘉信, 生命化学研究レター, 35, 38-42, 2011年02月01日
    日本語, 記事・総説・解説・論説等(学術雑誌)
  • 量子ドットを用いた移植幹細胞のin vivoイメージング
    渡辺将生, 渡辺将生, 湯川博, 加地範匡, 加地範匡, 宮本義孝, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 林衆治, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 91st, 2, 2011年
  • ナノ空間中のDNAダイナミクス制御に基づく長鎖DNA分離
    本山高貴, 本山高貴, 安井隆雄, 安井隆雄, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 23rd, 2011年
  • 治療薬物モニタリングチップ:血清サンプルの1ステップ分析
    杉浦佳奈子, 岡本行広, 加地範匡, 渡慶次学, 馬場嘉信, 杉浦佳奈子, 岡本行広, 加地範匡, 渡慶次学, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 91st, 2, 2011年
  • ミドリムシを利用した細胞分離法の開発(2)
    岡本行広, 中北行紀, 佐野貴大, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本分析化学会年会講演要旨集, 60th, 2011年
  • マイクロ化学チップの高集積化に向けた熱応答性バルブの開発
    内藤豊裕, 内藤豊裕, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 91st, 2, 2011年
  • マイクロ・ナノ構造体による1分子酵素反応解析
    飯嶋和樹, 飯嶋和樹, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 91st, 2, 2011年
  • ナノ構造体を用いた新規無標識バイオセンサの開発
    安井隆雄, 加地範匡, 岡本行広, 渡慶次学, 堀池靖浩, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 91st, 2, 2011年
  • 浮遊細胞培養のための還流培養チップの開発
    内藤豊裕, 内藤豊裕, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 24th, 2011年
  • 磁気ビーズによるイムノピラーチップのマイクロ流路内攪拌
    笠間敏博, 笠間敏博, 渡慶次学, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 24th, 2011年
  • 熱応答性自立駆動型マイクロバルブの開発
    内藤豊裕, 内藤豊裕, ARAYANARAKOOL Rerngchai, LE GAC Severine, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, VAN DEN BERG Albert, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 23rd, 2011年
  • ミドリムシによる細胞分離法の創成
    岡本行広, 岡本行広, 佐野貴大, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 91st, 3, 2011年
  • マイクロ流体制御下におけるプロテアーゼ反応の分子的検出
    小野島大介, 加地範匡, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 91st, 2, 2011年
  • Label-free detection of DNA using diffracted laser in nanowall array structures
    Takao Yasui, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yasuhiro Horiike, Yoshinobu Baba, 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011, MicroTAS 2011, 1, 54, 56, 2011年, [査読有り]
    We developed a new label-free system using nanowall array structures and realized label-free detection of small molecules and DNA. For the achievement of label-free detection, we used the diffracted laser beam, which was produced by the nanowall array structures when the laser was passed through the nanowall array structures perpendicularly. The diffracted signals showed a good linear relationship between the signal intensity and refractive indices, concentrations of molecules, or DNA length. Copyright © (2011) by the Chemical and Biological Microsystems Society., 英語
  • Single molecule enzymatic kinetics in subcellularsized nanospaces using pneumatic valve-assisted atto-liter chamber array devices
    K. Iijima, N. Kaji, Y. Okamoto, M. Tokeshi, Y. Baba, 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011, MicroTAS 2011, 2, 1092, 1094, 2011年, [査読有り]
    We developed the pneumatic valve-assisted atto-liter chamber array devices for quantitative investigation of enzymatic kinetics at the single molecular level. We fabricated chambers in the size ranges from a cell (fL) down to the subcellular organelle (aL) with and without inner-surface coating. The devices enable us to investigate quantitatively the effects of molecular confinement and surface coating on the single molecular enzymatic kinetics even at aL level. Copyright © (2011) by the Chemical and Biological Microsystems Society., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • DNA trapping at the interface of nanopillar and nanopillar-free regions for long DNA separation
    Koki Motoyama, Takao Yasui, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yoshinobu Baba, 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011, MicroTAS 2011, 1, 647, 649, 2011年, [査読有り]
    We report a technique of DNA separation based on DNA dynamics at the interface of nanopillar and nanopillar-free regions in nanopillar array chips. We investigated the residence time of DNA molecules at the interface of nanopillar and nanopillar-free regions, and revealed that DNA molecules were trapped at the interface by entirely introducing DNA molecules from nanopillar-free to nanopillar regions. The separation of DNA molecules could be achieved within five seconds based on the difference of residence time of each DNA. Copyright © (2011) by the Chemical and Biological Microsystems Society., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Epigenetic analysis of a single DNA molecule by microfluidic device with quantum dot
    Tatsuki Sano, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011, MicroTAS 2011, 1, 299, 301, 2011年, [査読有り]
    We report a rapid and simple epigenetic analysis based on microfluidic single DNA molecular methylation detection. We developed a microfluidic device to stretch a single DNA molecule and subsequent detection of a methylated DNA base by quantum dot (QD)-immobilized methyl binding domain (MBD) protein. A QD-MBD complex specifically bound to a methylated base of stretched DNA and was detected by a total internal reflection fluorescence microscope (TIRFM). Our method enables us to detect a number of methylation sites and identify the positions methylated simultaneously in the simple and rapid manner compared with the conventional methods. Copyright © (2011) by the Chemical and Biological Microsystems Society., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Microfluidic cell separation with antibody modified euglena by using phototaxis mediated migration
    Yukihiro Okamoto, Yukinori Nakakita, Takahiro Sano, Jumpei Morikawa, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011, MicroTAS 2011, 3, 1909, 1911, 2011年, [査読有り]
    We develop a microfluidic cell separation method which combined microfluidic devices and multifunctional Euglena. Multifunctional Euglena for cell separation was successfully prepared by the surface modification of Euglena cell membrane and its performances were confirmed. Mutlifunctional Euglena in the inlet attached cells, migrated inside the microchannel by phototaxis towards the outlet chamber, and brought specific cells to the outlet. After moving to the outlet, cells in the outlet were detached from Euglena. Since it is based on the unique characters of Euglena, our method needs only simple device and can deal with small to large amount variety kinds of samples including cells., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Long-time stress less cell culture chips for non-adhesive cells
    Toyohiro Naito, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yoshinobu Baba, 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011, MicroTAS 2011, 2, 816, 818, 2011年, [査読有り]
    We present a novel non-adhesive cell culture microdevice that has a loop channel with a micropost array for cell handling. Non-adhesive cells are focused on the upper side in the channel by the tilted micropost array, and they circulate around the same channel while medium was exchange. Our device enables us to culture non-adhesive cells for longer-term without stressful cell trapping. Copyright © (2011) by the Chemical and Biological Microsystems Society., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Temperature-driven self-actuated microvalve for PCR
    Toyohiro Naito, Rerngchai Arayanarakool, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Séverine Le Gac, Albert Van Den Berg, Y. Baba, 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011, MicroTAS 2011, 1, 248, 250, 2011年, [査読有り]
    We report here a novel chamber-sealing valve that is self-actuated by pressure change during the cyclic temperature changes in PCR processes. Actuation of our valve requirs only a heating device employed for PCR. An UV-curable polymer is used as a device material and it allowed us to realize temperature-driven valve actuation as well as to fabricate a 3D device. The self-actuated microvalve achieves the effective sealing of microchamber for PCR even at 90°C, which is essential to develop highly parallel PCR array device without any complicated actuator circuits. Copyright © (2011) by the Chemical and Biological Microsystems Society., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Nanowall array chips for DNA separation
    Takao Yasui, Noritada Kaji, Ryo Ogawa, Shingi Hashioka, Manabu Tokeshi, Yasuhiro Horiike, Yoshinobu Baba, 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011, MicroTAS 2011, 1, 638, 640, 2011年, [査読有り]
    A 25 s separation of DNA fragments (48.5 and 1 kbp fragments) was achieved by a nanowall array structure, although the separation of 1 kbp and 100 bp DNA fragments was not. Direct observation of a single DNA molecule indicates that it takes over 20 s for an elongated DNA molecule to relax inside the nanowall array structure. Numerical fitting of DNA molecular dynamics reveals that the balance between times for the transverse of an elongated DNA molecule and the relaxation process of a DNA molecule inside the nanowall array structure governs the separation of DNA. Copyright © (2011) by the Chemical and Biological Microsystems Society., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Microfluidic visualization of encounter complex in enzymatic digestion of single DNA molecule by dual molecular tagging
    D. Onoshima, N. Kaji, M. Tokeshi, Y. Baba, 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011, MicroTAS 2011, 3, 2061, 2063, 2011年, [査読有り]
    We combined molecular tagging with microfluidics to study kinematics in a single DNA molecular digestion. Moving tags of both DNA ends revealed initial breakup of a single DNA molecule into fragments induced by limited enzymatic digestion and subsequent rapid formation of transient structure in encounter complex. The method enables us to analyze rapid dissociation of weakly bound complexes derived from intramolecular transfer., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • ナノ構造体上での培養が幹細胞の増殖と分化へ及ぼす影響
    久保和稔, 岡本行広, 山本雅哉, 加地範匡, 渡慶次学, 田畑泰彦, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 22nd, 31, 2010年11月17日
    日本語
  • 量子ドットによる細胞移植後の幹細胞イメージング               
    渡辺将生, 湯川博, 鏡味幸真, 加地範匡, 宮本義孝, 岡本行広, 渡慶次学, 林衆治, 馬場嘉信, ナノ学会会報, 9, 1, 7-12, 2010年10月
    日本語, 機関テクニカルレポート,技術報告書,プレプリント等
  • ICP-MSによるマウスに静注した量子ドット標識化脂肪組織由来幹細胞の体内動態の精密測定               
    高崎 裕加, 渡辺 将生, 湯川 博, 梅村 知也, 加地 範匡, 岡本 行広, 宮本 義孝, 野口 洋文, 渡慶次 学, 林 衆治, 馬場 嘉信, 日本分析化学会講演要旨集, 59年会, 153, 153, 2010年09月
    (公社)日本分析化学会, 日本語
  • 幹細胞治療に対する量子ドットを用いたin vivoイメージング               
    湯川 博, 渡辺 将生, 鏡味 幸真, 宮本 義孝, 加地 範匡, 渡慶次 学, 野口 洋文, 馬場 嘉信, 林 衆治, JSMI Report, 3, 2, 49, 49, 2010年05月
    日本分子イメージング学会, 日本語
  • 高感度脳腫瘍細胞イメージング方法の開発               
    岡本 行広, 中尾 早織, 水野 正明, 加地 範匡, 渡慶次 学, 川西 悟基, 榊 裕之, 馬場 嘉信, JSMI Report, 3, 2, 157, 157, 2010年05月
    日本分子イメージング学会, 日本語
  • 幹細胞治療に対する量子ドットを用いたin vivoイメージング               
    湯川 博, 渡辺 将生, 鏡味 幸真, 宮本 義孝, 加地 範匡, 渡慶次 学, 野口 洋文, 馬場 嘉信, 林 衆治, JSMI Report, 3, 2, 166, 166, 2010年05月
    日本分子イメージング学会, 日本語
  • 新たな高性能分離分析法の提案
    岡本 行広, 加地 範匡, 渡慶次 学, 馬場 嘉信, 電気学会研究会資料. BMS, バイオ・マイクロシステム研究会 = The papers of Technical Meeting on Bio Micro Systems, IEE Japan, 2010, 1, 21, 25, 2010年01月29日
    日本語
  • 間隔の異なるナノピラーを集積化したナノバイオデバイスの開発
    安井隆雄, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 堀池靖浩, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 90th, 2, 2010年
  • イムノピラーチップ:血液中の疾病マーカーの多項目同時検出
    川上亜矢子, 岡本行広, 岡本行広, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 90th, 2, 2010年
  • ナノピラーチップを用いた簡便なスタッキング法の開発
    安井隆雄, 加地範匡, 岡本行広, 渡慶次学, 堀池靖浩, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 21st, 2010年
  • マイクロ構造体を用いた1分子酵素反応解析
    飯嶋和樹, 飯嶋和樹, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 21st, 2010年
  • 治療薬物モニタリングのための集積マイクロチップの開発
    杉浦佳奈子, 杉浦佳奈子, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, Chromatography, 31, Supplement 2, 2010年
  • マイクロバイオデバイスを用いた血漿中DNAの高効率抽出
    佐野竜輝, 岡本行広, 加地範匡, 渡慶次学, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 22nd, 2010年
  • マイクロ構造体を用いた1分子酵素反応解析
    飯嶋和樹, 飯嶋和樹, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 22nd, 2010年
  • ナノ構造体を用いた新規無標識検出法の開発
    安井隆雄, 加地範匡, 岡本行広, 渡慶次学, 堀池靖浩, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 22nd, 2010年
  • ナノ構造体を利用した新規無標識検出法の開発
    安井隆雄, 加地範匡, 岡本行広, 渡慶次学, 堀池靖浩, 馬場嘉信, 馬場嘉信, キャピラリー電気泳動シンポジウム講演要旨集, 30th, 2010年
  • CEDIA法を利用した治療薬物モニタリングチップの開発
    杉浦佳奈子, 杉浦佳奈子, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 21st, 2010年
  • 治療薬物モニタリングチップの開発:反応試薬の集積化と試料の定量採取
    杉浦佳奈子, 杉浦佳奈子, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 22nd, 2010年
  • ヒト全血から血漿の同時分離,定容,希釈を可能とするマイクロ流体システムの開発
    森川純平, 森川純平, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 22nd, 2010年
  • 細胞濃縮のためのマイクロ流体デバイスの開発
    内藤豊裕, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 90th, 2, 2010年
  • マイクロ流体制御下における核酸分解酵素反応の分子的検出
    小野島大介, 加地範匡, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 90th, 2, 2010年
  • 血中薬物濃度分析のためのマイクロ流体デバイスの開発
    杉浦佳奈子, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 90th, 2, 2010年
  • マイクロ流体デバイスを用いたDNA高次構造転移の1分子解析
    鈴木博詞, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本分析化学会年会講演要旨集, 59th, 2010年
  • マイクロ流体デバイスを利用したDNAコンフォメーション変化の1分子解析
    鈴木博詞, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 90th, 2, 2010年
  • ミドリムシが細胞を分離する
    岡本行広, 岡本行広, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 日本分析化学会年会講演要旨集, 59th, 2010年
  • ヒト全血から血漿の同時分離,定容,希釈を可能とするマイクロ流体システムの開発
    森川純平, 森川純平, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, Chromatography, 31, Supplement 2, 2010年
  • 温度応答性マイクロバルブの開発
    内藤豊裕, 内藤豊裕, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 22nd, 2010年
  • イムノピラーチップを用いた甲状腺刺激ホルモンの検出
    孫苗苗, 孫苗苗, 川上亜矢子, 川上亜矢子, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 22nd, 2010年
  • マイクロバイオデバイスを用いた血漿中DNAの高効率捕捉
    佐野竜輝, 佐野竜輝, 岡本行広, 岡本行広, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 東京コンファレンス講演要旨集, 2010, 2010年
  • 光硬化性樹脂を用いたダイヤフラム型ニューマティックバルブの作製法
    内藤豊裕, 内藤豊裕, ARAYANAKOOL Rerngchai, LE GAC Severine, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, VAN DEN BERG Albert, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 21st, 2010年
  • マイクロバイオデバイスを用いた血中DNAの高効率捕捉
    佐野竜輝, 岡本行広, 岡本行広, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 90th, 1, 2010年
  • 高感度脳腫瘍細胞検出の試み
    岡本行広, 中尾早織, 水野正明, 加地範匡, 渡慶次学, 川西悟基, 榊裕之, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 分析化学討論会講演要旨集, 71st, 2010年
  • 量子ドット内包リポソームの作製と特性評価
    中尾早織, 岡本行広, 岡本行広, 水野正明, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 川西悟基, 榊裕之, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 90th, 1, 2010年
  • 膜タンパク質解析のための脂質二重膜構築
    西川勝彦, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 90th, 3, 2010年
  • マイクロ構造体を利用した微小空間における1分子酵素反応解析
    飯嶋和樹, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 90th, 2, 2010年
  • 非標識型タンパク質検出手法を適用した毒素タンパク質の検出
    安藝理彦, WANG Jun, 小野島大介, 吉瀬智康, JIN Wanchun, 藤原健志, 有永健児, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 山田景子, 山田景子, 藤田省三, 馬場嘉信, 馬場嘉信, 太田美智男, 太田美智男, 横山直樹, 応用物理学関係連合講演会講演予稿集(CD-ROM), 57th, 2010年
  • マイクロ流体デバイスによる遺伝子治療用ナノデバイスの高速作製
    北添雄眞, 岡本行広, 岡本行広, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 小暮健太郎, 原島秀吉, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 90th, 3, 2010年
  • ミドリムシが細胞を分離する
    岡本行広, 岡本行広, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 東京コンファレンス講演要旨集, 2010, 2010年
  • 膜タンパク質解析のためのマイクロチャンバーアレイデバイス
    西川勝彦, 西川勝彦, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 22nd, 2010年
  • ミドリムシによる細胞分離の試み
    中北行紀, 中北行紀, 岡本行広, 岡本行広, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 22nd, 2010年
  • プロテアーゼ反応の分子的リアルタイムトラッキング
    小野島大介, 小野島大介, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 22nd, 2010年
  • Tracking of single DNA and protein molecules undergoing enzymatic degradation in fluid
    D. Onoshima, N. Kaji, M. Tokeshi, Y. Baba, 14th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2010, MicroTAS 2010, 3, 1439, 1441, 2010年, [査読有り]
    Here we demonstrate that a molecular motion detector in microfluidic channel can track nucleolytic and proteolytic degradations at a single molecule level. Central to these results is our observation that the microfluidic control worked well to visualize transient molecular processes clearly. A geometric analysis of the time course of molecular trajectories indicated hydrolysis rates and induction periods of each reaction., 英語
  • 国際会議 microTAS2010               
    渡慶次学, 馬場嘉信, 次世代センサ, 20, 15-18, 2010年
    日本語, 機関テクニカルレポート,技術報告書,プレプリント等
  • A microdevice with chaotic mixer to constract multifunctional envelope-type nanodevice for delivery system
    K. Kitazoe, Y. Okamoto, N. Kaji, M. Tokeshi, K. Kogure, H. Harashima, Y. Baba, 14th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2010, MicroTAS 2010, 2, 827, 829, 2010年, [査読有り]
    We report a new microdevice with a chaotic mixer for preparing multifunctional envelope-type nanodevice (MEND) for gene delivery system. Our developed device affords MEND with narrow size distribution, needs no troublesome procedures, and greatly reduces preparation time from 3 hours to 30 minutes compared to conventional MEND preparation method. Therefore, MEND prepared with our microdevice is expected to be applied in clinical use., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Development of three-step consolidating microchip for therapeutic drug monitoring
    K. Sugiura, N. Kaji, Y. Okamoto, M. Tokeshi, Y. Baba, 14th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2010, MicroTAS 2010, 2, 806, 808, 2010年, [査読有り]
    We developed easy-to-use microchip for therapeutic drug monitoring (TDM). Our assay platform consolidates three steps; preparation of reagents, quantitative liquid dispensing of sample and assay. The assay platform uses cloned enzyme donor immunoassay (CEDIA). The structure of the microchip permit liquid reagents and samples to be dispensed quantitatively [1]. Assay reagents were dispensed and lyophilized in the microchip. This microchip would permit one-step and rapid (5 min) assay, requiring only small volumes of reagent and sample (1.5 μl)., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Real-time observation of dna comformational transitions at a single-molecule level by microfluidic devices
    H. Suzuki, N. Kaji, Y. Okamoto, M. Tokeshi, Y. Baba, 14th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2010, MicroTAS 2010, 3, 1880, 1882, 2010年, [査読有り]
    We have developed a precise fluid control and a solution exchange system by a combination of novel microchannel designs and electroosmotic pumps for real-time observation of DNA conformational transitions at a single-molecule level. By using the microfluidic devices, we revealed the stepwise conformational transitions induced by ethanol solution., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Microfluidic sensor for the detection of DNA or protein by hybridization-based fluorescence enhancement or immunoassay-based fluorescence quenching
    J. Wang, M. Aki, D. Onoshima, K. Arinaga, N. Kaji, M. Tokeshi, S. Fujita, N. Yokoyama, Y. Baba, 14th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2010, MicroTAS 2010, 3, 1514, 1516, 2010年, [査読有り]
    We have developed a novel optical DNA/protein sensor which consists of single-stranded (ss) DNA-Cy3 probes on gold surface and one line-shape polydimethylsiloxane (PDMS) microfluidic channel. This novel ssDNA-Cy3 probes, which does not require hairpin-like stem-loop conformation, show similar advantages as traditional molecular beacon technique in this microfluidic sensor. This chip-based optical sensor showed strong fluorescence enhancement by the binding of cDNA or cDNA-biotin. After introduction of cDNA-biotin, streptavidin can be determined by fluorescence quenching. This sensor showed strong affinity and high sensitivity toward streptavidin, the minimum detectable concentration for streptavidin was 1 pM, equating to an absolute detection limit of 50 amol in this sensor., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Influence of nanostructure on proliferation and differentiation processes of stem cell
    Kazutoshi Kubo, Yukihiro Okamoto, Masaya Yamamoto, Noritada Kaji, Manabu Tokeshi, Yasuhiko Tabata, Yoshinobu Baba, 14th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2010, MicroTAS 2010, 1, 181, 183, 2010年, [査読有り]
    In this work, we used nanometer sized grooves which fabricated by nano imprinting method combined with a sol-gel process and observed the effect of nanostructure on mesenchymal stem cells (MSCs). MSCs on the nanostructures spread along the grooves in the first stage of proliferation, and then aggregated after differentiation to osteoblasts. In addition, the proliferation rate of MSCs on the nanostructures was suppressed compared to that on the flat surfaces. These results indicate that nanostructures change the environment around MSCs and affect the behavior of MSCs., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Label-free detection of biomolecules with nanowall arrays
    Takao Yasui, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yasuhiro Horiike, Yoshinobu Baba, 14th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2010, MicroTAS 2010, 1, 485, 487, 2010年, [査読有り]
    In this paper, we developed a new method for label-free detection of biomolecules by using the nanowall array chips. Our method is based on the detection of diffracted light by nanostructures inside a microchannel, and also has a great potential not only to distinguish the difference between water and buffer solution but detect biomolecules without any fluorescent molecules. Moreover, as for the detection limit, DNA molecules as much as zepto-mole level could be detected by using our label-free method., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • BIOINDUSTRY センシングバイオロジー-生命科学そして医療を支えるセンシング技術 量子ドットを用いた脂肪組織由来幹細胞のバイオイメージング
    鏡味幸真, 渡辺将生, 湯川 博, 加地範匡, 岡本行広, 渡慶次学, 林 衆治, 馬場嘉信, BIOINDUSTRY センシングバイオロジー-生命科学そして医療を支えるセンシング技術 量子ドットを用いた脂肪組織由来幹細胞のバイオイメージング, 26, 12, 14, 18, 2009年12月
    シーエムシー出版, 日本語, その他
  • 量子ドットを用いた脂肪組織由来幹細胞のバイオイメージング               
    鏡味幸真, 渡辺将生, 湯川博, 加地範匡, 岡本行広, 渡慶次学, 林衆治, 馬場嘉信, Bioindustry, 309, (5), 14-18, 2009年12月
    日本語, 機関テクニカルレポート,技術報告書,プレプリント等
  • マイクロチップを利用した簡易細胞アッセイ技術の開発               
    岡本 行広, 杉浦 佳奈子, 加地 範匡, 渡慶次 学, 馬場 嘉信, 日本バイオマテリアル学会大会予稿集, 31回, 316, 316, 2009年11月
    日本バイオマテリアル学会, 日本語
  • 臨床応用が始まるチップ疾患診断               
    渡慶次学, 舘知也, 馬場嘉信, 現代化学, 464, (11), 34-38, 2009年10月
    日本語, 機関テクニカルレポート,技術報告書,プレプリント等
  • 非標識型タンパク質検出手法の迅速化と高感度化 毒素タンパク質検出への応用               
    安藝 理彦, 汪 俊, 小野島 大介, 吉瀬 智康, 金 万春, 藤原 健志, 有永 健児, 加地 範匡, 渡慶次 学, 山田 景子, 藤田 省三, 馬場 嘉信, 太田 美智男, 横山 直樹, 日本分析化学会講演要旨集, 58年会, 52, 52, 2009年09月
    (公社)日本分析化学会, 日本語
  • ANYL 226-Micro- and nanostructures for DNA and protein analysis
    Noritada Kaji, Y. Okamoto, Manabu Tokeshi, Yoshinobu Baba, ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, 238, ., 2009年08月, [査読有り]
    AMER CHEMICAL SOC, 英語, 研究発表ペーパー・要旨(国際会議)
  • 【ますます重要になる細胞周辺環境(細胞ニッチ)の最新科学技術 細胞の生存、増殖、機能のコントロールから創薬研究、再生医療まで】細胞周辺環境のための材料加工・利用技術 医療に貢献するナノバイオ技術               
    岡本 行広, 加地 範匡, 渡慶次 学, 馬場 嘉信, 遺伝子医学MOOK, 別冊, ますます重要になる細胞周辺環境(細胞ニッチ)の最新科学技術, 161, 168, 2009年08月
    大きさや形状を厳密に制御した様々なナノ構造体の作製が可能となっており,近年これを生体試料へ適用する試みが行われている。なかでもナノピラー構造体を用いてDNAあるいは細胞の分離,細胞培養を行うと従来法をしのぐ性能を得ることが可能である。一方,ナノ材料の中でナノファイバーは生体試料の高性能分離媒体として利用可能であり,量子ドットは微量な生体試料の高感度検出試薬に加えて,癌細胞のみにアポトーシス誘起可能な治療材料としての利用も期待される。このようにナノテクノロジーを用いて細胞あるいは分子周辺環境を適切に整備すると,従来では見受けられない現象が観測されるとともに,従来法をしのぐ機能を生み出し,医療への多大な貢献が期待される。(著者抄録), (株)メディカルドゥ, 日本語
  • マイクロ流体デバイスを利用した血中薬物定量分析
    舘 知也, 加地 範匡, 渡慶次 学, 馬場 嘉信, TDM研究, 26, 3, s134, s134, 2009年06月
    (一社)日本TDM学会, 日本語
  • カップ積層型カーボンナノチューブの発光現象とマイクロチップ電気泳動への応用
    井上陽介, 岡本行広, 加地範匡, 渡慶次学, 馬場嘉信, 分析化学, 58, 6, 517, 521, 2009年06月
    Microchip electrophoresis (MCE) is one of the most suitable methods for biomolecular separation and analysis because of its superior characteristics. In biomolecular separation and analysis, laser induced fluorescent (LIF) detection is frequently employed in MCE and attains high sensitive detection. However, LIF detection requires the labeling of analytes, which contains troublesome procedures and results in decreasing of the separation efficiency. In addition, the labeling reaction at low concentration is significantly difficult, and thus trite high sensitive detection is not easily attained and has been desired. Here, we report on the possibility of cup-stacked carbon nanotubes (CSCNTs) for high sensitive label-free detection and high separation efficiency. At first we investigated fluorescence properties of CSCNTs. Our investigation revealed that supernatant solution of CSCNTs after centrifugation had fluorescence at around 500 rim, while CSCNTs Suspension did not. The application of CSCNTs for MCE enabled its to successfully separate and detect DNA without labeling it. Compared to the direct detection method, our method resulted in poor separation efficiency. However, by controlling of the CSCNTs' aspect ratio and the immobilization of functional molecules on the CSCNTs surfaces, we could improve separation efficiency and attain the separation of various samples without labeling samples., JAPAN SOC ANALYTICAL CHEMISTRY, 日本語, 速報,短報,研究ノート等(学術雑誌)
  • 実用化を目指したイムノアッセイチップの開発
    渡慶次 学, 電気学会研究会資料. OQD, 光・量子デバイス研究会, 2009, 42, 31, 32, 2009年05月07日
    日本語
  • Velocity gap theory developed for magnifying resolutions without changing separation mechanisms or separation lengths
    Yong Zhang, Jun Wang, Yukihiro Okamoto, Manabu Tokeshi, Noritada Kaji, Yoshinobu Baba, Analytical Chemistry, 81, 7, 2745, 2750, 2009年04月, [査読有り], [国際誌]
    Separation techniques, such as chromatography and electrophoresis, form the basis in many fields and are continually developed for better separation efficiency. The efforts normally involve a new mechanism together with sufficient separation length. We develop a velocity gap theory to make things simple. The theory is based on the discovery that the velocity gap (VG) effect could enlarge the distance between two moving objects. Mathematical deduction certified that the resolution may be magnified infinitely without changing the separation mechanism or the separation length. DNA separation confirmed its practical feasibility by achieving 2-5 times higher resolution on a microchip. Our results indicate that VG effect could enlarge the distance between two moving objects and may potentially be utilized to ameliorate separation efficiency. © 2009 American Chemical Society., 英語
  • ナノ構造体を用いたDNA解析               
    安井隆雄, 加地範匡, 岡本行広, 渡慶次学, 馬場嘉信, NEW GLASS, 24, (1), 22-27, 2009年03月
    日本語, 機関テクニカルレポート,技術報告書,プレプリント等
  • 新しい感染症検査の動向 マイクロ流路とIgY抗体を用いた黄色ブドウ球菌エンテロトキシンの微量・迅速・超高感度の検出
    金 万春, 山田 景子, 岡本 陽, 太田 美智男, 伊神 舞, 渡慶次 学, 加地 範匡, 馬場 嘉信, 木下 圭司, 水谷 誠, 村井 篤嗣, 並河 鷹夫, 日本細菌学雑誌, 64, 1, 106, 106, 2009年02月
    日本細菌学会, 日本語
  • ナノピラー中における非平衡輸送原理を利用したDNA分離
    安井隆雄, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 堀池靖浩, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 20th, 2009年
  • リアルタイムPCRチップの開発(2)
    内藤豊裕, 八橋愛, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 20th, 2009年
  • 細胞パターニングと濃度勾配を利用した細胞アッセイシステムの開発
    杉浦佳奈子, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 19th, 2009年
  • リアルタイムPCRのためのマイクロチップの開発
    八橋愛, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 89th, 2, 2009年
  • 免疫磁性ビーズを用いた簡便・迅速・高感度なメチシリン耐性黄色ブドウ球菌検出法の開発
    川上亜矢子, 岡本行広, 岡本行広, 加地範匡, 加地範匡, 山田景子, 山田景子, 渡慶次学, 渡慶次学, 太田美智男, 太田美智男, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 89th, 2, 2009年
  • 細胞パターニングとマイクロ流体チャネル内における濃度勾配を利用した細胞分析
    杉浦佳奈子, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 89th, 2, 2009年
  • インクジェット技術による新規試料導入法の開発
    井上陽介, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 89th, 1, 2009年
  • ナノ構造体での特異的な輸送現象を応用したDNA高速分離
    安井隆雄, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 堀池靖浩, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 89th, 2, 2009年
  • マイクロ流体デバイスを利用したDNA構造転移の1分子解析
    鈴木博詞, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 20th, 2009年
  • リアルタイムPCRチップの開発
    八橋愛, 内藤豊裕, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 19th, 2009年
  • ナノピラーチップ中での電気浸透流の解析
    安井隆雄, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 堀池靖浩, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 19th, 2009年
  • 細胞内におけるカチオン性リポソームの量子ドットによる動態可視化
    渡辺将生, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 89th, 2, 2009年
  • マイクロ流体デバイスを用いた多機能性エンベロープ型ナノ構造体の高速構築
    北添雄眞, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 小暮健太郎, 原島秀吉, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 89th, 2, 2009年
  • マイクロフルイディクスを用いた血液成分の網羅的解析-細胞・DNA・タンパク質-
    渡慶次学, 渡慶次学, 舘知也, 岡本行広, 岡本行広, 加地範匡, 加地範匡, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 東京コンファレンス講演要旨集, 2009, 2009年
  • 簡便・迅速なマルチプレックスイムノアッセイチップの開発
    渡慶次学, 渡慶次学, 伊神舞, 加地範匡, 加地範匡, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 89th, 1, 2009年
  • ヌクレアーゼ相互作用のマイクロ流体制御と1分子リアルタイム計測
    小野島大介, 加地範匡, 渡慶次学, 馬場嘉信, 中部化学関係学協会支部連合秋季大会講演予稿集, 40th, 2009年
  • マイクロ流路と1分子追跡法を用いたDNA結合タンパク質の反応機構解析
    小野島大介, 加地範匡, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 89th, 2, 2009年
  • DNAハイブリダイゼーションにより最適化した流路構造~たんぱく質検出への応用~
    安藝理彦, WANG Jun, 小野島大介, 有永健児, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 藤田省三, 馬場嘉信, 馬場嘉信, 横山直樹, 日本化学会講演予稿集, 89th, 1, 2009年
  • 新規膜タンパク質解析デバイスの開発
    西川勝彦, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 日本化学会講演予稿集, 89th, 2, 2009年
  • ナノデバイスによる生体分子解析
    安井隆雄, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 堀池靖浩, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 東京コンファレンス講演要旨集, 2009, 2009年
  • DNAハイブリダイゼーションにより最適化した流路構造~たんぱく質検出への応用~
    安藝理彦, WANG Jun, 小野島大介, 有永健児, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 藤田省三, 馬場嘉信, 馬場嘉信, 横山直樹, 応用物理学関係連合講演会講演予稿集, 56th, 3, 2009年
  • イムノピラーチップ:血液中の疾病マーカーの検出
    川上亜矢子, 田澤英克, 江端智彦, 岡本行広, 岡本行広, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 20th, 2009年
  • マイクロ流体デバイスを利用した多機能性エンベロープ型ナノ構造体の高速作製
    北添雄眞, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 小暮健太朗, 原島秀吉, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 20th, 2009年
  • Nanopillars and Nanoballs for DNA Analysis
    Kaji Noritada, Tokeshi Manabu, Baba Yoshinobu, NANOFLUIDICS: NANOSCIENCE AND NANOTECHNOLOGY, 179, 6, 179-191, 2009年, [査読有り]
    RSC Publishing, 英語, 速報,短報,研究ノート等(学術雑誌)
  • On-chip real-time PCR for genetic tug-of-war (g-TOW) experiment
    Toyohiro Naito, Ai Yatsuhashi, Noritada Kaji, Taeko Ando, Kazuo Sato, Hisao Moriya, Hiroaki Kitano, Yukihiro Okamoto, Manabu Tokeshi, Yosinobu Baba, Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 627, 629, 2009年, [査読有り]
    A micro-chip based real-time PCR device has been developed for biorobustness research and systems biology. The device is constructed of a silicon-glass chip, a Peltier element and a microscopy. With the device, amplification of target gene on a plasmid and housekeeping gene were detected simultaneously, and the copy number of the plasmid could be estimated. We had optimized the device, and achieved detection of fluorescent intensity increase in reaction channels. © 2009 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Poly (methyl methacrylate) microchip gel electrophoresis for the concentration and separation of aptamer and aptamer-thrombin complex with discontinuous buffers
    Jun Wang, Yong Zhang, Yeon Su Park, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 791, 793, 2009年, [査読有り]
    A simple continuous isotachophoresis (ITP)-based microchip gel electrophoresis (MGE) was firstly applied for the concentration and separation of aptamer and its thrombin complex in a single cross-form poly (methyl methacrylate) (PMMA) microchip. The aptamer and its thrombin complex can be simultaneously concentrated and separated by this method which does not require time-consuming steps and complicated chip design. We found that different terminating electrolyte (TE) ions lead to different concentration enhancement factors and that lower mobility of TE ions can get higher concentration results. After optimization of various impact factors, we successfully achieved about 2000-fold concentration of aptamer-thrombin complex. © 2009 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Non-equilibrium DNA transport in nanopillar array structures
    Takao Yasui, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yasuhiro Horiike, Yoshinobu Baba, Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1198, 1200, 2009年, [査読有り]
    In this paper, a novel DNA separation mechanism by nanopillar array structures was elucidated via single DNA molecule observation. We revealed that this new separation mechanism was based on non-equilibrium DNA transport under high electric field conditions. In fact, 10 seconds DNA separation was achieved without any loss of resolution. © 2009 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Easy cell assay device using two microchannels
    Kanako Sugiura, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yoshinobu Baba, Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1243, 1245, 2009年, [査読有り]
    We developed a new cell assay device. The assay device consists of two microchennels; a culture channel and a assay channel. In the culture channel, cells proliferated without continuous medium exchange and formed spots in line. And in the assay channel, a concentration gradient of reagent was formed by diffusion and the observation of cell spots permits cell assays with different concentration reagent at the same time. This device would permit easy and high throughput cell assay. © 2009 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Precisely size controlled liposome formation with a microfluidic device
    Mitsuru Shibata, Yukihiro Okamoto, Kaji Noritada, Manabu Tokeshi, Yoshinobu Baba, Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 624, 626, 2009年, [査読有り]
    We greatly improved our previous liposome preparation method [1] in terms of the flow direction and liposome solvent, and could prepare precisely size controlled liposomes (97-139 nm in diameter) with narrow size distribution (2.9-6.5% CV) easily and rapidly, which cannot be attained with conventional bulk methods and our previous one. Liposomes with specific sizes and narrow size distribution would greatly enhance drug delivery and gene therapy efficacy. © 2009 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • High-throughput microchip electrophoresis analysis with inkjet-injection method
    Yukihiro Okamoto, Yousuke Inoue, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 794, 796, 2009年, [査読有り]
    We established an inkjet injection method for robust microchip electrophoresis (MCE) separation and attained high-throughput analysis of biomolecules by automated inkjet injector for microchannel array. This injection method greatly reduces both analysis time and sample amount compared with conventional microchip electrophoresis, and allows us to realize highly parallelization of microchannel array on a smaller chip, since we do not need to use complicated arrays of cross channel sample injection [1]. Our method would facilitate omics and contribute to the highperformance clinical assay. © 2009 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Simultaneous separation, metering and dilution of plasma from human whole blood using a microchip with an interchannel microstructure
    Tomoya Tachi, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yoshinobu Baba, Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 427, 429, 2009年, [査読有り]
    In this research, we designed and operated a microchip with an interchannel microstructure for separation of plasma from human whole blood and for metering and diluting the plasma. The plasma separation was based on both cross-flow filtration and sedimentation of red blood cells in the microchannels. Metering and diluting the plasma was based on volume control of liquid in the microchannels by syringe pumps. Simultaneous operations to separate, meter and dilute plasma obtained from whole blood were done in microchannels using this microchip, and plasma precisely diluted by a factor of 6 was generated without hemolysis in the microchannels in about 3 minutes. This microchip is easily connected with other microchannels and microfluidic devices for quantitative analyses. © 2009 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Immuno-pillar chip: Multiplex detection of proteins in real samples
    Ayako Kawakami, Mai Ikami, Yukihiro Okamoto, Noritada Kaji, Jin Wanchun, Keiko Yamada, Michio Ohata, Hidekatsu Tazawa, Tomohiko Ebata, Manabu Tokeshi, Yoshinobu Baba, Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 436, 438, 2009年, [査読有り]
    We present a multiplex detection of Staphylococcus aureus enterotoxins (SEA, SEB and SED) in milk and disease markers (α-fetoprotein (AFP), C-reactive protein (CRP) and prostate-specific antigen (PSA)) in whole blood using immuno-pillar chips within 12 min or less. © 2009 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • A single molecule analysis for the conformational transition of DNA using microfluidics
    Hiroshi Suzuki, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yoshinobu Baba, Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 827, 829, 2009年, [査読有り]
    We have developed a real time monitoring system of DNA conformational transition at a single molecule level by using a microfluidic device. We revealed that the conformational transition process of a DNA induced by ethanol solution is totally depending on the concentration of ethanol. © 2009 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • A new microdevice to rapidly constract Multifunctional Envelope-type Nanodevice for gene therapy
    Katsuma Kitazoe, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Kentaro Kogure, Hideyoshi Harashima, Yoshinobu Baba, Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1267, 1269, 2009年, [査読有り]
    Multifunctional Envelope-type Nanodevice (MEND) is a promising gene delivery system. However, the application of MEND for the medical use has been prevented due to labor-intensive and time-consuming procedures in the preparation of MEND. In this paper, we report a microfluidic device which realizes to prepare MEND with narrow size distribution in 5 min (the conventional method needs 2 days). Our results strongly indicate that MEND prepared with our microfluidic device has a potential for medical use. © 2009 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Velocity gap theory developed for magnifying resolutions without changing separation mechanisms or separation lengths
    Yong Zhang, Jun Wang, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 788, 790, 2009年
    We developed velocity gap theory for enhancing separation resolutions. The theory is based on the discovery that velocity gap (VG) effect could enlarge the distance between two moving objects. DNA separation confirmed its practical feasibility by achieving 2-5 times higher resolution on a microchip. Our results indicate that VG effect could enlarge the distance between two moving objects and may potentially be utilized to ameliorate separation efficiency. © 2009 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • A simple and low-cost technique for fabricating microchannels and microstructures with high aspect ratio
    Daisuke Onoshima, Jun Wang, Michihiko Aki, Kenji Arinaga, Noritada Kaji, Manabu Tokeshi, Shozo Fujita, Naoki Yokoyama, Yoshinobu Baba, Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1587, 1589, 2009年, [査読有り]
    We developed a simple method for creating high-aspect-ratio (> 4) structures with sharp edge by using the lamination forming of a commercially available dry film photoresist in a conventional photolithography process. This type of fluidic structure is attractive to achieve a good separation and an ultra-sensitive detection of the liquid in microchannels readily. © 2009 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Atto- and femto-litre microfabrcated structures for investigating depression of enzyme activity at a single molecule reaction
    Kazuki Iijima, Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yoshinobu Baba, Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 854, 856, 2009年, [査読有り]
    In this work, we successfully measured a single enzyme reaction in a microfabricated chamber -(510 aL, 7.2 fL, 61 fL and 624 fL) and estimated the effect of enzyme adsorption and denaturation on the reaction rate with inner-surface coated and non-coated chambers. Our results indicate that a single enzyme reaction rate decreased with decreasing the chamber size and that reaction rate in coating chambers slightly increased compared to that in non-coated one. © 2009 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • A versatile method for the surface modification of the microchannels in polymer microchips               
    Yukihiro Okamoto, Yeon-Su Park, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Micro Total Analysis System 2008, 892-894, 2008年10月, [査読有り]
    英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • COLL 134-Aqueous phase fabrication of CdSe-based nanoparticles and their application for cancer cell imaging
    Yeon-Su Park, Yukihiro Okamoto, Jun Wang, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, 236, ., 2008年08月, [査読有り]
    AMER CHEMICAL SOC, 英語, 研究発表ペーパー・要旨(国際会議)
  • 治療薬物モニタリングのためのマイクロ化学システムの開発               
    渡慶次 学, 舘 知也, 加地 範匡, 馬場 嘉信, 日本分析化学会講演要旨集, 57年会, 63, 63, 2008年08月
    (公社)日本分析化学会, 日本語
  • 量子ドットを用いた非ウイルスベクターの細胞内トラフィッキングの可視化               
    水船 祥吾, 加地 範匡, 渡慶次 学, 馬場 嘉信, 日本分析化学会講演要旨集, 57年会, 98, 98, 2008年08月
    (公社)日本分析化学会, 日本語
  • マイクロ化学チップの医療応用
    渡慶次 学, 加地 範匡, 馬場 嘉信, 電気学会研究会資料. BMS, バイオ・マイクロシステム研究会 = The papers of Technical Meeting on Bio Micro Systems, IEE Japan, 2008, 1, 21, 24, 2008年02月12日
    日本語
  • ナノデバイスによるDNA解析
    安井 隆雄, 加地 範匡, 渡慶次 学, 馬場 嘉信, 電気学会研究会資料. OQD, 光・量子デバイス研究会, 2008, 1, 13, 16, 2008年02月08日
    日本語
  • square型ナノピラーチップデバイスを用いたrod-like-DNAの分離
    安井隆雄, 加地範匡, 加地範匡, 小川涼, 橋岡真義, 渡慶次学, 渡慶次学, 堀池靖浩, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 17th, 2008年
  • マイクロチップ電気泳動によるニューキノロン系耐性菌のSNPs解析
    吉川枝里, 加地範匡, 加地範匡, 川村久美子, 川村久美子, 太田美智男, 太田美智男, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 17th, 2008年
  • 浮遊細胞のためのマイクロ細胞培養チップの開発
    内藤豊裕, 加地範匡, 加地範匡, 安藤妙子, 橋岡真義, 佐藤一雄, 堀池靖浩, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 17th, 2008年
  • インクジェット技術を用いた超高性能マイクロチップ電気泳動法の開発
    井上陽介, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 中部化学関係学協会支部連合秋季大会講演予稿集, 39th, 2008年
  • ナノ構造体を用いた生体分子解析
    安井隆雄, 加地範匡, 加地範匡, 小川涼, 橋岡真義, 渡慶次学, 渡慶次学, 堀池靖浩, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 分析化学討論会講演要旨集, 69th, 2008年
  • ナノピラーチップデバイスによるDNA分離
    安井隆雄, 加地範匡, 小川涼, 橋岡真義, 堀池靖浩, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 88th, 2, 2008年
  • 高電場下におけるナノピラーチップ中でのDNAの泳動挙動解析
    安井隆雄, 加地範匡, 加地範匡, 小川涼, 橋岡真義, 渡慶次学, 渡慶次学, 堀池靖浩, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 中部化学関係学協会支部連合秋季大会講演予稿集, 39th, 2008年
  • 光圧力とシースフローを利用したマイクロ流路内における生死細胞分離
    村田聖弥, 加地範匡, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 88th, 2, 2008年
  • マイクロチャネルを利用したDNA凝縮の1分子リアルタイム観察
    藤吉健太郎, 加地範匡, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 88th, 2, 2008年
  • マイクロフルイディクスを利用した制限酵素反応の1分子トラッキング
    小野島大介, 加地範匡, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 88th, 2, 2008年
  • マイクロチャネルを利用したDNA凝縮過程の1分子観察
    藤吉健太郎, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 17th, 2008年
  • 分子トラッキングによる制限酵素反応のケモメトリック解析
    小野島大介, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 17th, 2008年
  • B型・C型エンテロトキシンの迅速検出
    渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 加地範匡, 加地範匡, 伊神舞, 分析化学討論会講演要旨集, 69th, 2008年
  • マイクロ化学チップを用いた新規リポソーム合成法の開発
    柴田充, 加地範匡, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 88th, 2, 2008年
  • マイクロ化学チップを用いたリポソーム新規作製法の開発
    柴田充, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 中部化学関係学協会支部連合秋季大会講演予稿集, 39th, 2008年
  • あらゆるポリマー製マイクロチップに適用可能な簡易表面改質法の開発
    岡本行広, 岡本行広, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 分析化学討論会講演要旨集, 69th, 2008年
  • 迅速診断のためのイムノアッセイデバイスの開発
    伊神舞, 山田景子, 渡慶次学, 加地範匡, 太田美智男, 馬場嘉信, 日本化学会講演予稿集, 88th, 1, 2008年
  • 量子ドットによる遺伝子の細胞内トラフィッキングイメージング
    間森千春, 加地範匡, 加地範匡, 岡本行広, 岡本行広, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 中部化学関係学協会支部連合秋季大会講演予稿集, 39th, 2008年
  • タンパク質解析チップ用セルロースフィルムコーティング
    岡田浩樹, 加地範匡, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 88th, 1, 2008年
  • 微小空間における1分子酵素反応の解析
    加地範匡, 加地範匡, 村原寿, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 分析化学討論会講演要旨集, 69th, 2008年
  • マイクロ化学デバイスによるタンパク質無細胞合成系の構築
    川名隆, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 17th, 2008年
  • 汎用ポリマー製マイクロチップへの簡易表面改質の試み
    岡本行広, 岡本行広, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 17th, 2008年
  • セルロース誘導体フィルムを用いた電気泳動チップへのコーティング法の開発とタンパク質解析への応用
    岡田浩樹, 岡田浩樹, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, バイオメディカル分析科学シンポジウム講演要旨集, 21st, 2008年
  • Microfluidic device to construct multifunctional envelope-type nanodevice for gene therapy
    K. Kitazoe, N. Kaji, Y. Okamoto, M. Tokeshi, K. Kogure, H. Harashima, Y. Baba, 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference, 1891, 1893, 2008年, [査読有り]
    In this paper, a new method to construct a multifunctional envelope-type nano device (MEND) on a chip is described. MEND is an extremely efficient non-viral vector for a gene delivery system, which is composed of a condensed DNA and a lipid envelope. Using the microfluidic device, MEND we constructed had stable size distribution for gene therapy. We also could make the volume of accessory product lower. © 2008CBMS., 英語
  • 最新のキャピラリー電気泳動とチップ電気泳動 キャピラリー・マイクロチップ電気泳動のための粘性可変分離媒体
    加地 範匡, 岡本 行広, 渡慶次 学, 馬場 嘉信, 生物物理化学, 52, 3, 95, 99, 2008年
    Various kinds of functional polymers have been developed for capillary and microchip electrophoresis. A versatile alternative to entangled and random-coiled polymers, Pluronic F127, is a typical functional polymer for a DNA separation matrix in microchip electrophoresis. This temperature-sensitive and viscosity-tunable polymer provided excellent resolutions over a wide range of DNA sizes based on a different separation mechanism compared with conventional polymers such as cellulose-derivatives. In this review, we will describe different type of viscosity-tunable polymers as well as our recent work using Pluronic F127.
    , 日本電気泳動学会, 日本語
  • Quantitative evaluation of dynamic coating on plastic microchips for preventing protein adsorption
    M. R. Mohamadi, T. Yasui, N. Kaji, M. Tokeshi, Y. Baba, 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference, 495, 497, 2008年, [査読有り]
    In the current research we studied coating efficiency of series of water soluble polymers with different hydrophilicity on microchip made of Poly(methyl methacrylate) (PMMA). Various characteristics of the dynamic coatings such as the efficiency for suppression of protein adsorption and electroosmotic flow (EOF), improving hydrophilicity of the microchannel surface and resolution for separation of protein samples were studied. The results give a better understanding of the interaction of protein samples to the PMMA surface. © 2008 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Nanotechnology meets plant biotechnology: Carbon nanotubes deliver DNA and incorporate into the plant cell structure
    Maged Fouad, Noritada Kaji, Mohammad Jabasini, Manabu Tokeshi, Yoshinobu Baba, 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference, 227, 229, 2008年, [査読有り]
    Carbon nanotubes (CNT) can intracellulary traffic through different cellular barriers and deliver biomolecules into living cells. However, their use in plants is limited by the cellulosic wall surrounding the plant cell. Here we show that CNT with immobilized cellulase can serve as an efficient DNA delivery system for plant cells. Tracking the cellular fate of nanotubes revealed two novel phenomena: (1)A possible nuclear localization and (2)When the transfected cell decides to differentiate into tracheary cell (water conducting cell), nanotubes were observed to incorporate into cellular structure. Our work aims at methodological development that paves the way toward on-chip-nanoscale-gene delivery applications. © 2008 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Liposome formation by counter-current flows in microchannels
    Mitsuru Shibata, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference, 1426, 1428, 2008年, [査読有り]
    In this paper, a new method to form liposomes in microfluidic device is presented. We demonstrated a novel formation method of liposomes by using counter-current flows in an asymmetric microfluidic device. We revealed that the counter-current flows enabled the liposome formation, which weren't based on diffusive mechanism of organic solvent and the control of size and size distribution of liposomes. We investigated the formation efficiency of liposomes of counter-current flows and co-current flows., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • External force responsible Nanogels for microchip electrophoresis of DNA
    K. Kondo, N. Kaji, S. Toita, K. Akiyoshi, M. Tokeshi, Y. Baba, 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference, 1132, 1134, 2008年, [査読有り]
    This paper describes a novel DNA separation matrix, nanogels, for microchip electrophoresis of DNA. This small (~30 nm in diameter) but multi-functional nanogels enabled easy loading into microchannels and provided excellent resolutions especially in the relatively small DNA fragments. © 2008 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Real-time monitoring of conformational transition of DNA at a single molecule level in microfluidic devices
    K. Fujiyoshi, N. Kaji, M. Tokeshi, Y. Baba, 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference, 441, 443, 2008年, [査読有り]
    In this paper, we successfully observed dynamics of conformational transition of DNA induced by ethanol and histone using microfluidic devices. Real-time monitoring of DNA contour length gave different contraction profiles in ethanol and histone solution at a single DNA molecule level. © 2008 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Inkjet-based DNA injector for microchip electrophoresis
    Yousuke Inoue, N. Kaji, Y. Okamoto, M. Tokeshi, Y. Baba, 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference, 1456, 1458, 2008年, [査読有り]
    We developed an inkjet-based DNA injector for microchip electrophoresis system based on a straight microchannel. The inkjet-based DNA injector enables us to precisely control injection volume of DNA and to use a simple straight microchannel for chip electrophoresis, whereas we need cross channel injector or T injector as well as complicated voltage programming for conventional chip electrophoresis. In this paper, microchip electorophoresis with inkjet injection (MCE-wii) for DNA separation was demonstrated. MCE-wii could reduce the sample volume by 0.1 % compared to that of the conventional cross injection., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Rapid and easy-to-use multiplex immunoassay device
    Mai Ikami, Manabu Tokeshi, Yukihiro Okamoto, Noritada Kaji, Yoshinobu Baba, 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference, 1111, 1113, 2008年, [査読有り]
    We developed a new rapid and easy-to-use immunoassay platform to simultaneously evaluate multiple biomarkers in a single sample. As proof of principle, we demonstrated a multiplex assay measuring three biomarkers: α-fetoprotein (AFP), C-reactive protein (CRP), and prostate-specific antigen (PSA). The assay was completed within 12 min, and the limit of detections (LODs) were several tenths of pg/ml for the three biomarkers. © 2008 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Nanopillar chips arranged in tilted array pattern for fast separation of DNA and proteins
    Takao Yasui, Noritada Kaji, Mohamad Reza Mohamadi, Ryo Ogawa, Shingi Hashioka, Manabu Tokeshi, Yasuhiro Horiike, Yoshinobu Baba, 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference, 432, 434, 2008年, [査読有り]
    In this paper, EOF mesurement and biomolecular separation (21-340 kDa in proteins, 1-48.5 kbp in DNA) were carefully studied by using nanopillar chips arranged in tilted array pattern with 100-nm spacing. We revealed that the nanopillar chips had an intrinstic function to suppress electro-osmotic flow (EOF), and as a result, DNA and SDS-protein complexes could be separated without any sieving matrices and surface coatings. © 2008 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • A microfluidic molecular tracking system detects a time-to-search DNA sequence to be cleaved by restriction enzymes
    D. Onoshima, N. Kaji, M. Tokeshi, Y. Baba, 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference, 18, 20, 2008年, [査読有り]
    A microfluidic analytical system, which uses simple technique to pick reacting DNA molecules out of a crowd of molecules during enzymatic reaction, was developed on the basis of single-molecule imaging. Restriction enzymes EcoR I and Not I with their target and non-target DNA were analyzed. With this system, we measured the duration difference of restriction-site-searching by these enzymes at the single-molecule level. © 2008 CBMS., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • マイクロ化学チップを用いた微小流路内におけるTODGAのNd(III)抽出分離特性
    伴康俊, 森田泰治, 菊谷善国, 原田雅幸, 池田泰久, 渡慶次学, 日本原子力学会秋の大会予稿集(CD-ROM), 2007, H59, 2007年09月07日
    日本語
  • Determination of Human Blood Sugar Level Using Microchip Electrophoresis
    E. Maeda, M. Kataoka, M. Hino, K. Kajimoto, N. Kaji, M. Tokeshi, Y. Shinohara, Y. Baba, Electrophoresis, 28, 16, 2927, 33, 2007年08月, [査読有り], [国際誌]
    A high-performance monitoring system for human blood glucose levels was developed using microchip electrophoresis with a plastic chip. The combination of reductive amination as glucose labeling with fluorescent 2-aminoacridone (AMAC) and glucose-borate complex formation realized the highly selective detection of glucose even in a complex matrix such as a blood sample. The migration time of a single peak, observed on an electropherogram of AMAC-labeled plasma, closely resembled that of glucose standard solution. The treatment of plasma with hexokinase or glucokinase for glucose phosphorylation resulted in a peak shift from approximately 145 to 70 s, corresponding to glucose and glucose-6-phosphate, respectively. A double-logarithm plot revealed a linear relationship between glucose concentration and fluorescence intensity in the range of 1-300 microM of glucose (r(2) = 0.9963; p <0.01), and the detection limit was 0.92 microM. Furthermore, blood glucose concentrations estimated from the standard curves of three subjects were compared with results obtained by conventional colorimetric analysis using glucose dehydrogenase. Good correlation was observed between methods according to simple linear regression analysis (p <0.05). The reproducibility of the assay was about 6.3-9.1% (RSD) and the within-days and between-days reproducibility were 1.6-8.4 and 5.2-7.2%, respectively. This system enables us to determine blood glucose with high sensitivity and accuracy, and will be applicable to clinical diagnosis., 英語
  • Microchip-based immunoassay
    Tomoya Tachi, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, BUNSEKI KAGAKU, 56, 7, 521, 534, 2007年07月
    Microchip-based immunoassay, which is immunoassay performed on a microchip, has recently been used in various fields owing to its advantages, such as reduction in sample and reagent consumption, short analysis time and simple operation. Different types of immunoassay have been applied to the miniaturization on a microchip. Material and surface modifications of a microchip, introducing and moving samples and detection must be taken into consideration in order to realize a microchip-based immunoassay. Also, the microchip system should be designed according to a type of immunoassay. In the present review article, we explain the types and classifications of immunoassays and describe important points for developing a microchip-based immunoassay. We then introduce several examples of microchip-based immunoassay., JAPAN SOC ANALYTICAL CHEMISTRY, 日本語, 書評論文,書評,文献紹介等
  • Microchip electrophoresis for detection of circle-to-circle amplification products towards sensitive and rapid DNA analysis
    Laili Mahmoudian, Jonas Melin, Mohamad Reza Mohamadi, Keiko Yamada, Michio Ohta, Noritada Kaji, Manabu Tokeshi, Mats Nilsson, Yoshinobu Baba, Chemistry Letters, 36, 3, 396, 397, 2007年03月05日, [査読有り]
    A new method for fast and precise analysis of circle-to-circle amplification (C2CA) products by microchip electrophoresis has been developed. Stable C2CA products were produced by applying a new enzymatic step to C2CA. Detection was carried out within 55s with RSD of migration time of 3.6% (n = 6) enabling reproducibility and high speed. A real sample of bacterial pathogen (V. Cholerae) at single nucleotide level was detected successfully based on this method. Copyright © 2007 The Chemical Society of Japan., 英語, 速報,短報,研究ノート等(学術雑誌)
  • 新しい抗体固定化法を用いたマイクロチップイムノアッセイの開発
    渡慶次 学, 角田 正也, 宮川 堅次, 塗料の研究, 147, 41, 44, 2007年03月
    関西ペイント, 日本語
  • Rapid bonding of Pyrex glass microchips
    Yoshitake Akiyama, Keisuke Morishima, Atsuna Kogi, Yoshikuni Kikutani, Manabu Tokeshi, Takehiko Kitamori, ELECTROPHORESIS, 28, 6, 994, 1001, 2007年03月
    A newly developed vacuum hot press system has been specially designed for the thermal bonding of glass substrates in the fabrication process of Pyrex glass microchemical chips. This system includes a vacuum chamber equipped with a high-pressure piston cylinder and carbon plate heaters. A temperature of up to 900 degrees C and a force of as much as 9800 N could be applied to the substrates in a vacuum atmosphere. The Pyrex substrates bonded with this system under different temperatures, pressures, and heating times were evaluated by tensile strength tests, by measurements of thickness, and by observations of the cross-sectional shapes of the microchannels. The optimal bonding conditions of the Pyrex glass substrates were 570 degrees C for 10 min under 4.7 N/mm(2) of applied pressure. Whereas more than 16 h is required for thermal bonding with a conventional furnace, the new system could complete the whole bonding processes within just 79 min, including heating and cooling periods. Such improvements should considerably enhance the production rate of Pyrex glass microchemical chips. Whereas flat and dust-free surfaces are required for conventional thermal bonding, especially without long and repeated heating periods, our hot press system could press a fine dust into glass substrates so that even the areas around the dust were bonded. Using this capability, we were able to successfully integrate Pt/Ti thin film electrodes into a Pyrex glass microchip., WILEY-BLACKWELL, 英語
  • バイオ関連トピックス (特集 第10回化学・生命科学マイクロシステム国際会議(μTAS2006)) -- (研究概要)
    渡慶次 学, 馬場 嘉信, 化学とマイクロ・ナノシステム, 6, 1, 5, 7, 2007年03月
    化学とマイクロ・ナノシステム研究会, 日本語
  • Dynamic coating using methylcellulose and polysorbate 20 for nondenaturing electrophoresis of proteins on plastic microchips.
    Mohamad Reza Mohamadi, Laili Mahmoudian, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Electrophoresis, 28, 5, 830, 6, 2007年03月, [査読有り], [国際誌]
    A dynamic coating using methylcellulose (MC) and a nonionic detergent (polysorbate 20) was developed, which controlled protein adsorption onto the surface of microchannels on a microchip made of poly(methyl methacrylate) (PMMA). Optimum concentration of polysorbate 20 in combination with the range of MC concentrations controlled the protein adsorption onto the microchannel surface, and increased the solubility of the protein samples while facilitating the injection of high concentrations of MC solutions into the microchannels. Higher concentrations of nonionic detergent increased the EOF mobility as opposed to the electrophoretic mobility and caused the electrophoresis to fail. Nondenaturing microchip electrophoresis of protein samples with molecular masses ranging from 20 to 100 kDa were completed in 100 s. Also, successful separation of a BSA sample and its complex with anti-BSA mAb ( 220 kDa) was achieved on a PMMA microchip. The separation exhibited high reproducibility in both migration time (RSD = 1%) and peak area (RSD = 10-15%)., 英語
  • 量子ドットによる細胞イメージング
    加地 範匡, 渡慶次 学, 馬場 嘉信, 電気学会研究会資料. BMS, バイオ・マイクロシステム研究会 = The papers of Technical Meeting on Bio Micro Systems, IEE Japan, 2007, 1, 25, 28, 2007年01月30日
    日本語
  • Rapid and simultaneous multiple genotyping of human Y chromosome from a human blood sample by on-chip enzymatic digestion and microchannel array electrophoresis coupled with blood sample pretreatment, and microscale PCR
    Lihua Zhang, Toshikatsu Shinka, Yutaka Nakahori, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Sensors and Actuators, B: Chemical, 121, 1, 124, 128, 2007年01月30日, [査読有り]
    In this paper, with distinct six DNA markers, 47z, SRY, YAP, 12f2, TB4Y and UTY, as the judgement standard, a combined technique for the rapid haplotyping (multiple genotyping) of human Y chromosome was developed by a DNA analysis system. By Generation capture disk, 5 min were enough to extract and purify DNA from five samples with only 4.5 L blood for each one. Consequently, LightCycler was chosen for the amplification of the six fragments of each sample. Under the optimized conditions, the simutaneous amplification of DNA extracted from five samples could be finished within 25 min. Among the six genomic fragments of each sample, the polymorphisms of YAP and 12f2 could be distinguished directly from PCR products. The other four were single nucleotide polymorphisms. Therefore, microchip-based restriction fragment length polymorphism analysis was carried out. With a 12-channel microchip, in 8 min, two blood samples could be analyzed at the same time through on-chip digestion and the subsequent separation of DNA fragments in the channel. In summary, with the above-mentioned technique, microscale haplotyping of human Y chromosome could be finished at the average speed of 10 min/sample with only 4.5 μL blood. © 2006 Elsevier B.V. All rights reserved., 英語, 速報,短報,研究ノート等(学術雑誌)
  • DNA分離に対するナノピラーデバイスの特性解析と最適化
    安井隆雄, 加地範匡, 加地範匡, 小川涼, 橋岡真義, 渡慶次学, 渡慶次学, 堀池靖浩, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 16th, 2007年
  • マイクロチャネルを利用したB型からA型DNAへのコンフォメーション変化の1分子計測
    藤吉健太郎, 加地範匡, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 87th, 2, 2007年
  • ナノ構造体を用いた分離分析法
    加地範匡, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 分析化学討論会講演要旨集, 68th, 2007年
  • 量子ドット複合体による非ウイルス性ベクターの細胞内導入過程の可視化
    水船翔悟, 加地範匡, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 87th, 2, 2007年
  • 光硬化性樹脂を用いた新規イムノアッセイデバイスの開発
    伊神舞, 渡慶次学, 渡慶次学, 加地範匡, 加地範匡, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 15th, 2007年
  • 3次元構造を利用したマイクロミキサー
    大里恵子, 渡慶次学, 渡慶次学, 加地範匡, 加地範匡, 尾本悠輔, 鈴木教和, 酒井康彦, 社本英二, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 15th, 2007年
  • マイクロ流体デバイスを用いた無細胞タンパク質合成系の構築
    川名隆志, 加地範匡, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 87th, 2, 2007年
  • 量子ドットをプローブとしたDNAの1分子相互作用解析
    小野島大介, 加地範匡, 渡慶次学, 馬場嘉信, 日本化学会講演予稿集, 87th, 2, 2007年
  • 新規イムノアッセイデバイスの開発
    渡慶次学, 渡慶次学, 伊神舞, 加地範匡, 加地範匡, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 高分子学会予稿集(CD-ROM), 56, 2 Disk1, 2007年
  • ナノデバイスによる1分子バイオ計測
    小野島大介, 加地範匡, 渡慶次学, 馬場嘉信, 高分子学会予稿集(CD-ROM), 56, 2 Disk1, 2007年
  • 微小空間内における酵素反応のモレキュラークラウディング効果
    村原寿, 加地範匡, 加地範匡, 渡慶次学, 渡慶次学, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 16th, 2007年
  • 光硬化性樹脂を用いた新規イムノアッセイデバイスの評価
    伊神舞, 渡慶次学, 渡慶次学, 加地範匡, 加地範匡, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 16th, 2007年
  • A New On-Chip Platform For Rapid And Easy-To-Use Immunoassay
    Mai Ikami, Manabu Tokeshi, Noritada Kaji, Yoshinobu Baba, Micro Total Analysis System 2007, 2007, 655-657, 657, 2007年
    英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Development of new microfluidic immunoassay chips
    Tokeshi Manabu, Ikami Mai, Kaji Noritada, Baba Yoshinobu, PROCEEDINGS OF THE FIRST SHENYANG INTERNATIONAL COLLOQUIUM ON MICROFLUIDICS, 199-200, 200, 2007年, [査読有り]
    This paper reports a new platform for chip-based immunoassay using photopolymer and antibody-immobilized small-sized polystyrene beads (1 mu m phi). Hydrogel pillars, which contain the antibody-immobilized polystyrene beads, in microchannels were fabricated by photolithography. By using this format, we realized (i) rapid analysis (a few minutes), (ii) easy handling (no need pump and valve), (iii) low-cost (disposable), (iv) small volume (1 droplets (0.25 mu L) of sample and reagents), and (v) high sensitivity., NORTHEASTERN UNIV SHENGYANG, 英語, 速報,短報,研究ノート等(学術雑誌)
  • A novel high efficient and speed construction method of a multi functional envelope-type nano device on microdevice               
    Hiroshi Kuramoto, Noritada Kaji, Kentarou Kogure, Manabu Tokeshi, Yasuo Shinohara, Hideyoshi Harashima, Yoshinobu Baba, Micro Total Analysis System 2007, 2007, 781-783, 2007年
    英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Cell Sorting Of Live And Dead Cells By Laser Radiation Pressure And Sheath Flow In Microchannel
    Masaya Murata, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Micro Total Analysis System 2007, 2007, 116-118, 118, 2007年, [査読有り]
    We have developed a novel cell sorting technique for live and dead cells by using optical tweezers (1064 nm Nd; YAG Laser) and sheath flow in a PDMS microchip. The dead cells stained by Trypan Blue have low refraction index than the live cells. Therefore, by using appropriate laser power and flow rate only, the live cells could be trapped by optical tweezers., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Molecular Crowding Effect On Enzymatic Reaction In A Fl-Microchamber To Mimic Crowded Intracellular Enviromnent
    Hisashi Murahara, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Micro Total Analysis System 2007, 2007, 1003-1005, 1005, 2007年
    In this work, we investigated how the size of reaction space would affect enzyme activities to understand intracellular enzyme kinetics. Two approaches were used to create pseudo-intracellular environments: a high concentration of polymers in bulk state and microfabricated chambers. Both approaches were carefully compared and we found that an enzyme activity was inhibited in 7.2 fL chamber by molecular crowding effect as in the case of highly concentrated polymer solution., 日本語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Dna Separation By Square Patterned Nanopillar Chips
    Takao Yasui, Noritada Kaji, Ryo Ogawa, Shingi Hashioka, Manabu Tokeshi, Yasuhiro Horiike, Yoshinobu Baba, Micro Total Analysis System 2007, 2007, 1207-1209, 1209, 2007年
    In this paper, the mechanism of DNA separation by different array-pattern nanopillar chips and the effect of nanopillar spacing were carefully studied. We revealed that array-pattern of nanopillars and nanopillar spacing dominates the separation mode, and furthermore, the square patterned nanopillar chips could achieve a high-resolution and high-speed separation., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Viscosity-Tunable Polymer For Microchip Electrophoresis
    Daisuke Kuroda, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Micro Total Analysis System 2007, 2007, 841-843, 843, 2007年
    A versatile alternative to entangled and random-coiled polymers, Pluronic F127, has been developed for a DNA separation matrix in microchip electrophoresis. This temperature-sensitive and viscosity-tunable polymer provided excellent resolutions over a wide range of DNA sizes based on a different separation mechanism compared with conventional polymers such as cellulose-derivatives., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Quantum-Dot-Connected Dna For Single-Molecular Nanobiodevices               
    Daisuke Onoshima, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Micro Total Analysis System 2007, 2007, 1619-1621, 2007年
    英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • 800 Fold Signal Enhancements By Transient Isotachophoresis In Linear Polymer Solution For Immunoassay Of Hsa On Standard Cross Channel Microchips
    Mohamad Reza Mohamadi, Laili Mahmoudian, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Micro Total Analysis System 2007, 2007, 1402-1404, 1404, 2007年
    A fully automated preconcentration and stacking method based on transient isotachophoresis (ITP) on a standard cross channel microchip made of poly (methylmethacrylate) PMMA has been reported. Previously reported ITP has been either on a special chip design or required a hydrodynamic pressure for sample injection and a pause in the electrophoresis process which caused low reproducibility in analysis. In this work sample injection, preconcentration and separation are done continuously and are controlled solely by a sequential voltage switching program. The ITP followed by nondenaturing gel electrophoresis was applied for immunoassay of HSA., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Dynamics Measurement Of Structural Change Of Helical Polymer Using Thermal Lens Microscopy And Microfluidic Technique
    Keiko Osato, Manabu Tokeshi, Noritada Kaji, Kazuma Mawatari, Takehiko Kitamori, Eiji Yashima, Yoshinobu Baba, Micro Total Analysis System 2007, 2007, 1565-1567, 1567, 2007年
    In this paper, we report a new on-chip system for dynamics measurement of structural change of polymer. This experimental system consists of a thermal lens microscope (TLM) and a microchip. Using this system, we demonstrated that it can measure dynamically molecular structural change in a microchannel by time-resoled measurement., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Micromixer Based On Baker'S Transformation
    Keiko Osato, Manabu Tokeshi, Noritada Kaji, Yusuke Omoto, Yasuhiko Sakai, Eiji Shamoto, Yoshinobu Baba, Micro Total Analysis System 2007, 2007, 309-311, 311, 2007年
    Herein we report the development of a new passive micromixer with 3-D structure based on Baker's transformation. The 3-D structure was fabricated on an oxygen-free copper block by using an ultrasonic elliptical vibration cutting method [1] and was used as a mold master. Using this master mold, we fabricated a PDMS micromixer chip. The mixing efficiency of the micromixer was evaluated by measuring the fluorescence image that results from mixing of two liquids (FITC solution and water). From these measurements, we found that the mixing efficiency at relatively high flow rate conditions is much better than that of low flow rate conditions. The mixing behavior in the microchannel was observed by a confocal fluorescence microscopy., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Fast Differentiative Quantitation Of Salivary And Pancreatic Amylase Activities In Human Blood By Microchip Electrophoretic Separation Of Substrate/Hydorlysate Coupled With Immunoinhibition               
    Eiki Maeda, Masatoshi Kataoka, Yasuo Shinohara, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Micro Total Analysis System 2007, 2007, 65-67, 2007年
    英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • マイクロチップイムノアッセイ               
    舘知也, 加地範匡, 渡慶次学, 馬場嘉信, 分析化学, 56, 7, 521-534, 2007年, [招待有り]
    日本語, 速報,短報,研究ノート等(学術雑誌)
  • Nanotechnology in Proteome Analysis               
    Y. Zhang, N. Kaji, M. Tokeshi, Y. Baba, Expert Review of Proteomics, 4, 4, 565-572, 2007年, [査読有り]
    英語, 速報,短報,研究ノート等(学術雑誌)
  • Influences of electroosmotic flows in nanopillar chips on DNA separation: Experimental results and numerical simulations
    Noritada Kaji, Akio Oki, Ryo Ogawa, Yuzuru Takamura, Takahiro Nishimoto, Hiroaki Nakanishi, Yasuhiro Horiike, Manabu Tokeshi, Yoshinobu Baba, Israel Journal of Chemistry, 47, 2, 161, 169, 2007年, [査読有り]
    The various potential factors affecting the performance of nanopillar chips on DNA separation were investigated from the viewpoints of both numerical calculations and actual experiments. To yield higher performance and replace the conventional DNA separation techniques such as microchip electrophoresis, the phenomenon specific to the nanopillar chips should be deeply understood. In this paper, although various factors affecting the performance of the nanopillar chips are considered, we focused on the effect of electroosmotic flow, which is particularly noticeable in quartz-made nanopillar chips. High-resolution separation of DNA was realized when an electroosmotic flow was suppressed by simply using a higher concentration of buffer, but DNA separation failed in the presence of an electroosmotic flow. It was confirmed from the numerical simulations and the direct observations that the deformation of DNA band during the injection process was induced by electroosmotic flow and consequently led to a poor resolution., 英語, 速報,短報,研究ノート等(学術雑誌)
  • マイクロリアクターを用いた高効率化学合成               
    渡慶次学, 菊谷善国, バイオインダストリー, 24, 2, 53-58, 2007年, [招待有り]
    日本語, 速報,短報,研究ノート等(学術雑誌)
  • 【ナノテクノロジーとバイオセンサ】マイクロチップ分析関連 マイクロ・ナノバイオデバイスによるDNA・蛋白質解析
    渡慶次 学, 加地 範匡, 馬場 嘉信, 臨床検査, 50, 12, 1567, 1575, 2006年11月
    (株)医学書院, 日本語
  • マイクロ・ナノデバイスによる生体分子解析と疾患診断
    加地 範匡, 渡慶次 学, 馬場 嘉信, 現代化学, 425, 31, 38, 2006年08月, [招待有り]
    東京化学同人, 日本語, 速報,短報,研究ノート等(学術雑誌)
  • Nanotechnology for genomics & proteomics
    Mohamad Reza Mohamadi, Laili Mahmoudian, Noritada Kaji, Manabu Tokeshi, Hiroshi Chuman, Yoshinobu Baba, Nano Today, 1, 1, 38, 45, 2006年02月, [査読有り]
    This review, though not comprehensive, looks at recent developments in nanodevices for genomics and proteomics and some of the new applications in biomedicine. © 2006 Elsevier Ltd. All rights reserved., 英語, 速報,短報,研究ノート等(学術雑誌)
  • マイクロチャネルを利用したB型からA型DNAへのコンフォメーション変化の直接観察
    加地範匡, 藤吉健太郎, 渡慶次学, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 13th, 2006年
  • マイクロチップゲルシフトアッセイによるDNAとタンパク質の相互作用解析
    井上園子, 片岡正俊, 片岡正俊, 篠原康雄, 加地範匡, 渡慶次学, 馬場嘉信, 馬場嘉信, 日本分析化学会年会講演要旨集, 55th, 2006年
  • マイクロチップ電気泳動による糖鎖解析
    Fuquan Dang, 掛樋一晃, 石川満, 加地範匡, 渡慶次学, 馬場嘉信, 馬場嘉信, 日本分析化学会年会講演要旨集, 55th, 2006年
  • マイクロチャネルを用いた無細胞タンパク質合成系の構築
    川名隆志, 加地範匡, 渡慶次学, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 13th, 2006年
  • 量子ドットを用いた1分子DNA-タンパク質間相互作用のオンチップ計測
    小野島大介, 加地範匡, 渡慶次学, 馬場嘉信, 日本化学会バイオテクノロジー部会シンポジウム講演要旨集, 9th, 2006年
  • マイクロチップゲルシフトアッセイを用いたDNA-NFκBの相互作用に関する研究
    井上園子, 片岡正俊, 片岡正俊, 篠原康雄, 加地範匡, 渡慶次学, 馬場嘉信, 馬場嘉信, 化学とマイクロ・ナノシステム研究会講演要旨集, 13th, 2006年
  • Continuous flow chemical processing on a microchip using microunit operations and a multiphase flow network (vol 47, pg 434, 2005)
    M Tokeshi, T Kitamori, PROGRESS IN NUCLEAR ENERGY, 48, 2, 182, 182, 2006年
    PERGAMON-ELSEVIER SCIENCE LTD, 英語, その他
  • On-chip construction of a multifunctional envelope-type nano device for a non-viral gene delivery system
    Hiroshi Kuramoto, Noritada Kaji, Kentarou Kogure, Manabu Tokeshi, Yasuo Shinohara, Hideyoshi Harashima, Yoshinobu Baba, Micro Total Analysis Systems - Proceedings of MicroTAS 2006 Conference: 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences, μTAS2006, 1005, 1007, 2006年, [査読有り]
    We developed a simple microdevice to construct a multifunctional envelope-type nano device (MEND) on a chip. MEND is an extremely efficient technology for a non-viral gene delivery system, however, the existing method to construct it is time-consuming, labor intensive, and tedious task. In the simple microdevice developed here, just by changing flow rate and concentrations of materials in microchip, we succeeded to construct MEND efficiently and easily. © 2006 Society for Chemistry and Micro-Nano Systems., 英語
  • Direct monitoring of B- to a-DNA conformational transition at a single molecule level induced by ethanol in microfluidic devices
    Kentaro Fujiyoshi, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Micro Total Analysis Systems - Proceedings of MicroTAS 2006 Conference: 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences, μTAS2006, 1396, 1398, 2006年, [査読有り]
    This paper presents the development of a direct monitoring system of conformational transition from B- to A-DNA in microfluidics devices. Well-controlled laminar flows produced elongated large single DNA molecules onto chemically modified surfaces, and furthermore, ease of liquid-exchange operation of microfluidics devices enabled dynamic observation of B- to A-DNA conversion. © 2006 Society for Chemistry and Micro-Nano Systems., 英語
  • ナノバイオデバイスのバイオ応用               
    渡慶次 学, 加地範匡, 細胞工学, 25, 873-877, 2006年, [招待有り]
    日本語, 速報,短報,研究ノート等(学術雑誌)
  • Microchip electrophoretic mobility shift assay for detecting interactions of DNA-transcription factor NFκB
    Sonoko Inoue, Masatoshi Kataoka, Yasuo Shinohara, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Micro Total Analysis Systems - Proceedings of MicroTAS 2006 Conference: 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences, μTAS2006, 903, 905, 2006年
    Microchip electrophoretic mobility shift assay (μEMSA) has been developed for DNA-protein interaction study, and finally, we succeed in detecting the interaction of DNA and Nuclear Factor κB (NFκB) within only 200 s. Since the method provides quantitative data simultaneously, kinetics data analysis of DNA-protein interaction was also conducted. © 2006 Society for Chemistry and Micro-Nano Systems., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • A microchip-based fluorescence polarization immunoassay
    Tomoya Tachi, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Micro Total Analysis Systems - Proceedings of MicroTAS 2006 Conference: 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences, μTAS2006, 816, 818, 2006年
    A simple and rapid immunoassay on a microchip has been developed by using fluorescence polarization measurement. We here report a microchip-based quantitative analysis of a kind of bronchodilator, theophylline, which is important for the treatment of asthma. © 2006 Society for Chemistry and Micro-Nano Systems., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Determination of blood sugar using microchip electrophoresis
    Eiki Maeda, Masatoshi Kataoka, Yasuo Shinohara, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Micro Total Analysis Systems - Proceedings of MicroTAS 2006 Conference: 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences, μTAS2006, 813, 815, 2006年
    In this study, high-performance monitoring system for blood sugar was developed by using microchip electrophoresis with a plastic chip. A combination of a reductive amination as sugar labeling and sugar-borate complex formation realized highly selective detection of blood sugar even in a blood sample. This paper demonstrates that this system enables us to determine blood sugar with high sensitivity and high accuracy, and it will be applicable to clinical diagnosis. © 2006 Society for Chemistry and Micro-Nano Systems., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Novel physically adsorbed polymer coating on PMMA microchip with multi channel array for high-throughput protein analysis
    Hiroki Okada, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Micro Total Analysis Systems - Proceedings of MicroTAS 2006 Conference: 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences, μTAS2006, 401, 403, 2006年
    For protein analysis, polymeric microchip was extremely incompatible with protein samples. To overcome the incompatibility, we developed a novel physically adsorbed polymer coating, which was a new approach and different from conventional coating methods, on PMMA microchip using cellulose derivatives as the coating reagents. The coating method remarkably progressed analytical performance and we could successfully separate 5 proteins dependent of their own sizes with high reproducibility (RSD; within 3 %, n=12) on coated PMMA microchip with 12 channels array. © 2006 Society for Chemistry and Micro-Nano Systems., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • APPLICATION OF 1,4-DIOXANE TO ENHANCING SELECTIVITY IN ANALYSIS OF GLYCOSAMINOGLYCAN DISACCHARIDES BY MICROCHIP ELECTROPHORESIS               
    Yong Zhang, Guichen Ping, Bingmei Zhu, Hiroshi Chuman, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba, Micro Total Analysis System 2006, μTAS2006, 2006年
    英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • Electrokinetic preconcentration and highly stacking gel electrophoresis for analysis of high molecular weight protein complexes on a plastic microchip
    Mohamad Reza Mohamadi, Laili Mahmoudian, Noritada Kaji, Manabu Tokeshi, Hiroshi Chuman, Yoshinobu Baba, Micro Total Analysis Systems - Proceedings of MicroTAS 2006 Conference: 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences, μTAS2006, 353, 355, 2006年
    An efficient dynamic coating using methylcellulose and a non-ionic detergent (Tween-20) was developed which controlled protein adsorption onto the surface of microchannels on a microchip made of poly (methyl methacrylate), PMMA. Highly stacking microchip electrophoresis under non-denaturing condition was used for analyzing high molecular weight protein complexes on a plastic microchip. The method has the efficiency of 6*10 6 plate/m for a complex of mAb-HSA with MW of ∼220kDa and with the detection limit of few pM. © 2006 Society for Chemistry and Micro-Nano Systems., 英語, 研究発表ペーパー・要旨(全国大会,その他学術会議)
  • 細胞培養のためのマイクロチップ温度制御装置の開発
    田中有希, 西中正弘, 馬渡和真, 渡慶次学, 渡慶次学, 北森武彦, 北森武彦, 分析化学討論会講演要旨集, 66th, 16, 2005年04月30日
    日本語
  • マイクロチャネル内気液二相流を利用した化学プロセス
    渡慶次 学, 北森 武彦, 混相流, 19, 1, 25, 30, 2005年03月15日
    日本混相流学会, 日本語
  • 熱レンズ顕微鏡
    馬渡 和真, 比企 伸一郎, 福澤 隆, 山口 淳, 服部 明彦, 渡慶次 学, 北森 武彦, 光学, 33, 12, 708, 714, 2004年12月10日
    応用物理学会分科会日本光学会, 日本語
  • 単一分子計測法
    馬渡 和真, 渡慶次 学, 北森 武彦, ぶんせき, 357, 506, 512, 2004年09月05日
    日本分析化学会, 日本語
  • マイクロ流路内の物質拡散・反応解析
    河村勉, 山内雅世, 渡慶次学, 北森武彦, 化学とマイクロ・ナノシステム研究会講演要旨集, 10th, 2004年
  • 超微量分析・精密合成を可能にするマイクロ化学チップ (特集1 バイオとガラス)
    渡慶次 学, 火原 彰秀, 上野 雅晴, ニュ-ガラス, 19, 3, 5, 13, 2004年
    ニュ-ガラスフォ-ラム, 日本語
  • 非蛍光性分子の超高感度検出
    渡慶次学, 馬渡和真, 火原彰秀, 北森武彦, 応用物理, 73, 6, 741, 748, 2004年
    応用物理学会, 日本語
  • High Throughput Bonding Technique of Pyrex Chip using Hot Pressing               
    Keisuke Morishima, Yoshitake Akiyama, Manabu Tokeshi, Takehiko Kitamori, Proceedings of the Micro Total Analysis Systems, Malmö, Sweden, (2004)., 410, 412, 2004年
  • Chemical processing on microchips for analysis, synthesis, and bioassay
    M Tokeshi, Y Kikutani, A Hibara, K Sato, H Hisamoto, T Kitamori, ELECTROPHORESIS, 24, 21, 3583, 3594, 2003年11月
    This review describes our recent research on miniaturization of chemical systems. We have developed a miniaturization methodology based on pressure-driven multiphase laminar flow and a highly sensitive detection tool, the thermal lens microscope. Some representative applications of the methodology in the fields of analysis, synthesis, and bioassay are described., WILEY-V C H VERLAG GMBH, 英語, 書評論文,書評,文献紹介等
  • マイクロ流体デバイス内の化学反応流における3次元的流れ場による拡散評価
    篠原 恭介, 杉井 康彦, 岡本 孝司, 火原 彰秀, 渡慶次 学, 北森 武彦, 可視化情報学会誌. Suppl. = Journal of the Visualization Society of Japan, 23, 2, 113, 116, 2003年10月15日
    可視化情報学会, 日本語
  • マイクロチップを用いたイムノアッセイシステム
    渡慶次 学, 佐藤 記一, 北森 武彦, バイオサイエンスとインダストリー = Bioscience & industry, 61, 7, 449, 454, 2003年07月01日
    バイオインダストリ-協会, 日本語
  • マイクロPIV法を用いたマイクロチップ内の水-油流場の可視化
    杉井 康彦, 岡本 孝司, 火原 彰秀, 渡慶次 学, 北森 武彦, 可視化情報学会誌. Suppl., 23, 1, 301, 304, 2003年07月01日
    可視化情報学会, 日本語
  • マイクロPIVとマイクロLIF法を用いたマイクロチップ内の化学反応流場の可視化・計測
    篠原 恭介, 杉井 康彦, 岡本 孝司, 火原 彰秀, 渡慶次 学, 北森 武彦, 可視化情報学会誌. Suppl., 23, 1, 297, 300, 2003年07月01日
    可視化情報学会, 日本語
  • Microchip-based chemical and biochemical analysis systems
    K Sato, A Hibara, M Tokeshi, H Hisamoto, T Kitamori, ADVANCED DRUG DELIVERY REVIEWS, 55, 3, 379, 391, 2003年02月
    This review focuses on chemical and biochemical analysis systems using pressure-driven microfluidic devices or microchips. Liquid microspace in a microchip has several characteristic features, for example, short diffusion distances, high specific interfacial area and small heat capacity. These characteristics are the key to controlling micro unit operations and constructing new integrated chemical systems. By combining multiphase laminar flow and the micro unit operations, such as mixing, reaction, extraction and separation, continuous flow chemical processing systems are realized in the microchip format. By applying these concepts, several different analysis systems were successfully integrated on a microchip. In this paper, we introduce the microchip-based chemical systems for wet analysis of cobalt ion, multi-ion sensors, immunoassay, and cellular analysis. (C) 2002 Elsevier Science B.V. All rights reserved., ELSEVIER SCIENCE BV, 英語, 書評論文,書評,文献紹介等
  • マイクロ化学システム
    渡慶次 学, 火原 彰秀, 北森 武彦, 計測と制御 = Journal of the Society of Instrument and Control Engineers, 42, 1, 29, 32, 2003年01月10日
    日本語
  • ミクロ空間における分子輸送と溶媒抽出--マイクロ化学システムの鍵
    久本 秀明, 渡慶次 学, 火原 彰秀, 日本イオン交換学会誌, 14, 1, 38, 43, 2003年01月
    日本イオン交換学会, 日本語
  • Integration of chemical and biochemical analysis systems into a glass microchip
    K Sato, A Hibara, M Tokeshi, H Hisamoto, T Kitamori, ANALYTICAL SCIENCES, 19, 1, 15, 22, 2003年01月
    This review focuses on the integration of chemical and biochemical analysis systems into glass microchips for general use. By combining multiphase laminar flow driven by pressure and micro unit operations, such as mixing, reaction, extraction and separation, continuous-flow chemical processing systems can be realized in the microchip format, while the application of electrophoresis-based chip technology is limited. The performances of several analysis systems were greatly improved by microchip integration because of some characteristics of microspace, i.e., a large specific interface area, a short molecular diffusion time, a small heat capacity and so on. By applying these concepts, several different analysis systems, i.e., wet analysis of cobalt ion, multi-ion sensor, immunoassay, and cellular analysis, were successfully integrated on a microchip. These microchip technologies are promising for meeting the future demands of high-throughput chemical processing., JAPAN SOC ANALYTICAL CHEMISTRY, 英語, 書評論文,書評,文献紹介等
  • Multichannel Micro ELISA System               
    Kiichi Sato, Maho Yamanaka, Manabu Tokeshi, Keisuke Morishima, Takehiko Kitamori, Proceedings of the Micro Total Analysis Systems,Squaw Valley, USA, (2003)., 781, 784, 2003年
  • マイクロチップ抽出場の創製からマイクロチップ化学へ
    渡慶次 学, 火原 彰秀, 久本 秀明, 北森 武彦, ぶんせき, 329, 257, 262, 2002年05月05日
    日本分析化学会, 日本語
  • Development of Integration ELISA System Using a Multichannel Microchip               
    Maho Yamanaka, Kiichi Sato, Manabu Tokeshi, Keisuke Morishima, Hajime Katou, Takehiko Kitamori, 25th International Symposium on Capillary Chromatography, Riva del Garda, Italy, (2002), -, -, 2002年
  • Microchip-Based Enzyme-Linked Immunosorbent Assay (ELISA) System               
    Kiichi Sato, Maho Yamanaka, Manabu Tokeshi, Keisuke Morishima, Takehiko Kitamori, Proceedings of the Micro Total Analysis Systems,Nara, Japan, (2002)., 311, 312, 2002年
  • サロン マイクロチップに集積したミクロ実験室
    火原 彰秀, 渡慶次 学, 北森 武彦, 固体物理, 36, 12, 883, 889, 2001年12月
    アグネ技術センタ-, 日本語
  • マイクロ分析システム
    佐藤 記一, 久本 秀明, 渡慶次 学, 木村 博子, 北森 武彦, BME : bio medical engineering, 15, 10, 24, 30, 2001年10月10日
    日本語
  • 複合化学プロセスのマイクロチップ集積化
    火原 彰秀, 渡慶次 学, 北森 武彦, 電気化学および工業物理化学 : denki kagaku, 69, 8, 620, 623, 2001年08月05日
    電気化学会, 日本語
  • インテグレーテッド・ケミストリー - 化学技術のオーダーシフト革命 -
    久本 秀明, 渡慶次 学, 北森 武彦, 化学と工業 = Chemistry and chemical industry, 54, 5, 564, 568, 2001年05月01日
    日本化学会, 日本語
  • 熱レンズ顕微鏡 (特集 新しい顕微鏡)
    火原 彰秀, 渡慶次 学, 北森 武彦, 光技術コンタクト, 39, 4, 212, 219, 2001年04月
    日本オプトメカトロニクス協会, 日本語
  • マイクロチップ分析システムを用いた超微量物質の超高感度・高速分析
    渡慶次 学, 佐藤 記一, 木村 博子, 北森 武彦, Biomedical research on trace elements, 12, 1, 85, 90, 2001年03月31日
    日本微量元素学会, 日本語
  • Integrated multilayer flow system on a microchip
    A Hibara, M Tokeshi, K Uchiyama, H Hisamoto, T Kitamori, ANALYTICAL SCIENCES, 17, 1, 89, 93, 2001年01月
    We utilized microchip technology and found that the multilayer flow of liquids can be formed in microchannels. Liquid/liquid interfaces were formed parallel to the side wall of the microchannels, because the surface tension and friction force are stronger than the force of gravity. A water/ethylacetate/water interface was formed in a 70-mum-wide and 30-mum-deep channel. The interface was observed to be quite stable and to be maintained for a distance of more than 18 cm. As an example of a multilayer flow application, we demonstrated the liquid/liquid extraction of Co-dimethylaminophenol complex in a microchannel. The solvent-extraction process of the complex into m-xylene in the multilayer flow was found to reach equilibrium in 4 s, while it took 60 s in a simple two-phase extraction., JAPAN SOC ANALYTICAL CHEMISTRY, 英語
  • 一分子をはかる
    火原 彰秀, 渡慶次 学, 北森 武彦, ぶんせき, 310, 591, 596, 2000年10月05日
    日本分析化学会, 日本語
  • Sub-single molecule determination of non-fluorescent species by scanning thermal lens microscope and its application to single cell measurement
    T Kitamori, M Uchida, A Egami, K Sekiguchi, JJ Zheng, T Sawada, M Tokeshi, K Sato, H Kimura, SCANNING AND FORCE MICROSCOPIES FOR BIOMEDICAL APPLICATIONS II, 3922, 67, 72, 2000年
    We have developed a thermal lens microscope which induces and detects photothermal effect at sub-single molecules level in/on liquids and condensed media. The thermal lens microscope can determine non-fluorescent molecules without receiving serious effect of light scattering in/on various condensed phase substances, and it can be applied to imaging of the distribution of non-fluorescent molecules by scanning on the sample. These characteristics of the thermal lens microscope are suitable for ultra sensitive analysis and imaging of biomedical substance in/on a single cell, separation media, and microfabricated chemical devises. We applied the thermal lens microscope to determine an ultratrace chemical species in various media., SPIE-INT SOC OPTICAL ENGINEERING, 英語
  • Doppler Profiles of the Balmer-α and -β Lines of the Excited Hydrogen Atoms(n=3, 4) Produced in Ar^+-C_2H_6 Collisions
    TOKESHI Manabu, NAKASHIMA Keiji, OGAWA Teiichiro, Chemistry letters, 1996, 11, 943, 944, 1996年11月
    日本語

書籍等出版物

  • AI・ナノ・量子による超高感度・迅速バイオセンシング               
    笠間敏博, 渡慶次学, マイクロ流体デバイスによる超早期がん診断
    シーエムシー出版, 2021年08月, [分担執筆]
  • 分析化学実技シリーズ機器分析編19 マイクロ流体分析               
    渡慶次学, 真栄城正寿, 佐藤記一, 佐藤香枝, 火原彰秀, 石田晃彦, 序論, 免疫分析(イムノアッセイ), デジタルマイクロフルイディクス
    共立出版, 2020年10月, [共著]
  • Microfluidic Technologies and Platform for Protein Crystallography: Applications of Microfluidic Systems in Biology and Medicine (Manabu Tokeshi, ed.)               
    Maeki Masatoshi, Manabu Tokeshi
    Springer, 2019年05月, [共著]
  • Applications of Microfluidic Systems in Biology and Medicine               
    Manabu Tokeshi
    Springer, 2019年05月, [編者(編著者)]
  • Microfabrication and Microfluidic Devices for Drug Delivery: Microfluidics for Pharmaceutical Applications (Hélder A. Santos, Dongfei Liu, Hongbo Zhang, Eds.)               
    Niko Kimura, Masatoshi Maeki, Manabu Tokeshi
    Elsevier, 2019年01月, [共著]
  • Micro/Nano Devices for Chemical Analysis               
    Manabu Tokeshi, Kiichi Sato
    MDPI, 2017年, [共編者(共編著者)]
  • 紙を使った分析・診断チップの現状と可能性/機能紙最前線, NPO法人機能紙研究会編集, 第1部進化し続ける機能紙               
    真栄城正寿, 渡慶次学
    加工技術研究会, 2017年, [共著]
  • Fabrication and Evaluation of Microfluidic Immunoassay Devices with Antibody-Immobilized Micrbeads Retained in Porous Hydrogel Micropillars: Microchip Diagnostics in Methods in Molecular Biology (Valérie Taly, Jean-Louis Viovy, Stéphanie Descroix eds.)               
    Toshihiro Kasama, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Springer, 2017年, [共著]
  • Nanopillars, Nanowires and Nanoballs for DNA and Protein Analysis: Nanofluidcs, 2nd Edition, RSC Nanoscience & Nanotechnology No.41 (Joshua Edel, Aleksandar Ivanov, MinJun Kim, eds.)               
    Noritada Kaji, Takao Yasui, Manabu Tokeshi, Yoshinobu Baba
    RSC Publishing, 2016年, [共著]
  • 診断・分析機能を集積した免疫分析チップ/バイオチップの基礎と応用               
    笠間敏博, 渡慶次学
    シーエムシー出版, 2015年, [共著]
  • Carbon Nanotubes and Modern Nanoagriculture/Nanotechnology and Plant Sciences: Nanoparticles and Their Impact on Plants (Manzer H. Siddiqui, Mohamed H. Al-Whaibi, Mohammad Firoz, Eds.)               
    Maged F. Serag, Naritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Springer, 2015年, [共著]
  • Size-Selective Synthesis of Ultrasmall Hydrophilic CdSe Nanoparticles in Aqueous Solution at Room Temperature/Nanoparticles in Biology and Medicine: Methods and Protocols, Methods in Molecular Biology(Mikhail Soloviev, Ed.)               
    Yeon-Su Park, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    Humana Press, 2012年, [共著]
  • ナノピラーデバイス・ナノウォールデバイス/ナノ融合による先進バイオデバイス(民谷栄一監修)               
    安井隆雄, 渡慶次学, 馬場嘉信
    シーエムシー出版, 2011年, [共著]
  • マイクロ分析, 光熱変換分析/改訂六版分析化学便覧               
    渡慶次 学
    丸善, 2011年, [単著]
  • PCR内蔵型DNAチップ/試料分析講座1巻DNA/RNA               
    岡本行広, 加地範匡, 渡慶次学, 馬場嘉信
    丸善, 2011年, [共著]
  • DNA前処理/PCR・チップ/バイオチップ実用化ハンドブック               
    加地範匡, 岡本行広, 渡慶次学, 馬場嘉信
    エヌ・ティー・エス, 2010年, [共著]
  • 医療に貢献するナノバイオ技術/遺伝子医学「ますます重要になる細胞周辺環境の科学技術-細胞の生存、増殖、機能のコントロールから再生医療まで」               
    岡本行広, 加地範匡, 渡慶次学, 馬場嘉信
    メディカルドゥ, 2009年, [共著]
  • 熱レンズ顕微鏡/分光測定入門シリーズ第10巻顕微分光法-ナノ・マイクロの世界をみる分光法(日本分光学会編)               
    渡慶次学, 火原彰秀
    講談社サイエンティフィク, 2009年, [共著]
  • 蛍光計測/MEMS/NEMS工学全集               
    渡慶次学, 馬場嘉信
    テクノシステム, 2009年, [共著]
  • ナノテクノロジーを利用した超高性能DNA解析手法/マイクロ・ナノ化学チップと医療・環境・バイオ分析, 第5編応用技術               
    岡本行広, 加地範匡, 渡慶次学, 馬場嘉信
    技術教育出版, 2009年, [共著]
  • マイクロ化学チップの特性と動作性/マイクロ・ナノ化学チップと医療・環境・バイオ分析, 第2編マイクロ化学チップの動作と原理               
    渡慶次学
    技術教育出版, 2009年, [単著]
  • Nano-Fabricated Structures for Biomolecule Analysis/Bio-Inspired Nanomaterials and Nanotechnology(Yong Zhou, Ed.)               
    Noritada Kaji, Yukihiro Okamoto, Manabu Tokeshi, Yoshinobu Baba
    Nova Publisher, 2009年, [共著]
  • Nanopillars and Nanoballs for DNA Analysis/Nanofluidcs(J. Edel, A. J. deMello, Eds.)               
    Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    RSC Publishing, 2009年, [共著]
  • ガラスのウェットエッチング-マイクロ化学チップの作製法/ウェットエッチングのメカニズムと処理パラメーターの最適化               
    渡慶次学, 菊谷善国
    サイエンス&テクノロジー, 2008年, [共著]
  • Flow Analysis in Microfluidic Devices/Advances in Flow Methods of Analysis(M. Trojanowicz, Ed.)               
    Manabu Tokeshi, Takehiko Kitamori
    Wiley-VCH, 2008年, [共著]
  • ナノバイオデバイス/ナノバイオ計測の実際               
    馬場嘉信, 渡慶次学, 加地範匡
    講談社, 2007年, [共著]
  • ミクロ相分離/ナノバイオ辞典               
    渡慶次学
    テクノシステム, 2007年, [単著]
  • Solvent Extraction on Chips               
    Manabu Tokeshi, Takehiko Kitamori
    CRC Press, 2007年, [共著]
  • Nanoscale DNA Analysis               
    Laili Mohmoudian, Moham, Reza Mohamadi, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba
    CRC Press, 2007年, [共著]
  • 化学反応高度分析のためのマイクロ化学チップ~熱レンズ分光分析装置の開発/マイクロリアクターテクノロジー               
    渡慶次学
    NTS, 2005年, [単著]
  • 分子輸送制御, 化学システム設計/マイクロ化学チップの技術と応用(化学とマイクロ・ナノシステム研究会監修)               
    渡慶次学
    丸善, 2004年
  • マイクロケミカルテクノロジー/コンビナトリアルテクノロジー:明日を開く‘もの作り’の新世界(鯉沼秀臣, 川崎雅司監修)               
    渡慶次学, 北森武彦
    丸善, 2004年, [共著]
  • マイクロチップ化学プロセスの設計, 超高感度検出器, マイクロ分析化学システム/インテグレーテッド・ケミストリー(北森武彦編)               
    渡慶次学
    シーエムシー出版, 2004年
  • マイクロ流路による微小バイオテクノロジー/バイオエンジニアリングマテリアル(石原一彦編)               
    渡慶次学, 佐藤記一, 北森武彦
    フロンティア出版, 2004年, [共著]
  • マイクロ分析チップ/ナノテクノロジーハンドブックIV編 バイオ・化学を使う               
    渡慶次学
    オーム社, 2003年, [単著]
  • ナノ・マイクロテクノロジー/第6版化学便覧応用化学編I, II編基盤的化学技術, 11章次世代基盤化学技術               
    金幸夫, 渡慶次学
    丸善, 2003年, [共著]
  • ヨクト分析-ナノをはるかに超えて/基礎から学ぶナノテクノロジー(平尾一之編)               
    渡慶次学, 北森武彦
    東京化学同人, 2003年, [共著]
  • Micro Integrated Chemical Systems for General Use/Lab-On-A-Chip: Miniaturized Systems for (Bio) Chemical Analysis and Synthesis(R.E.Oosterbroek, A.van den Berg, Eds.)               
    Yoshikuni Kikutani, Akihide Hibara, Hideaki Hisamoto, Manabu Tokeshi, Takehiko Kitamori
    Elsevier, 2003年, [共著]

所属学協会

  • アメリカ化学会               
  • 化学とマイクロ・ナノシステム学会               
  • 日本分光学会               
  • 日本分析化学会               
  • 日本化学会               
  • Japan Society of Molecular Science               
  • American Chemical Society               
  • The Institute of Electrical Engineering of Japan               
  • The Spectroscopical Society of Japan               
  • The Japan Society for Analytical Chemistry               
  • The Chemical Society of Japan               
  • 英国王立化学会               

共同研究・競争的資金等の研究課題

  • エンジニアード脂質粒子の創成とその応用
    科学研究費助成事業
    2024年04月01日 - 2029年03月31日
    渡慶次 学, 真栄城 正寿, 篠田 渉
    日本学術振興会, 基盤研究(S), 北海道大学, 24H00038
  • 化学テロ発生現場において神経剤を検知する紙製流体デバイスの創製
    科学研究費助成事業
    2020年04月01日 - 2023年03月31日
    宮口 一, 渡慶次 学, 山口 晃巨
    吸水性の高い紙を基材とした紙製流体デバイスは、浸潤により自律的に液体が移動するため、電源やポンプが不要であり、リソースが限られるテロ現場における危険物質の検知に適していると考えられる。また、安価で大量生産が可能であることも、実用化のためには利点となる。
    令和3年度は、前年度に設計・最適化した紙製流体デバイスについて、種々の化学剤及び有機リン系農薬に対する応答性能を評価した。その結果、神経剤(サリン、タブン、VX及びRVX)は、有機リン系農薬(ジクロルボス、パラオキソン)より約1000倍高感度であることが明らかとなった。さらに、実際の現場資料において想定される有機溶媒等の妨害物質の影響についても検討した結果、種々の有機溶媒共存下においても正しく検知可能であり、かつ偽陽性を生じないことが明らかとなった。なお、DMSOで偽陽性を生じたものの、水で20倍に希釈した場合は偽陽性を生じなかったことから、測定前の希釈が偽陽性の防止及び有機リン系農薬との識別に有効であることが明らかとなった。
    さらに、ドアノブやスイッチからの難揮発性神経剤の検知を想定して、ステンレス板及びプラスチック板上に残ったVXを展開液を浸潤させた綿で拭き取り、その展開液をそのまま紙製検査チップに導入して検査した。その結果、約5 ngのVXが検知可能であった。
    以上のことから、検出性能の点においては実用化の域に達したと考え、これまでの成果をまとめて論文公表及び特許出願を行った。
    日本学術振興会, 基盤研究(C), 科学警察研究所, 20K09279
  • 育種・染色体操作を用いたサケ科魚類の魚卵アレルゲン性低減化の試み
    科学研究費助成事業
    2020年04月01日 - 2023年03月31日
    清水 裕, 笹岡 友季穂, 藤本 貴史, 平松 尚志, 石田 晃彦, 渡慶次 学, 佐伯 宏樹
    進捗状況を3項目に分けて述べる。
    1.不妊魚の作出:ニジマスの卵と凍結保存したブラウントラウトあるいはサクラマスの精子を受精し、第二極体放出阻止処理により作出された雑種三倍体候補(A:ニジマス×ブラウントラウト、B:ニジマス×サクラマス)の倍数性を調査した。その結果、候補Aでは全25個体で、候補Bでは1個体を除く30個体が三倍体であった。これらの個体はPITタグで標識し、現在も継続して飼育している。(藤本)
    2.魚卵アレルゲン検知系の構築:引き続き、ニジマス卵アレルゲンであるβ’-component(BC)のペーパー免疫分析デバイスの構築に取り組んだ。デバイスは濾紙にインクを印刷して加熱する常法により作製し、インクで囲まれた領域を分析反応ゾーンとした。分析は、反応ゾーンに新規作製した抗BC抗体を固定化して試料、酵素標識抗BC抗体、発色試薬を順に加えて行う手順とした。本手法では、従来並みの感度(検出感度:約1 ng/mL)の分析が従来の1/100の時間(約20分)で可能となった。(渡慶次、石田)
    加えて、交雑種に対応した検知系に使用する抗体の作成のため、サクラマス排卵からBCを精製し、これを家兎に免疫し抗血清を作製した。(平松)
    3.不妊化魚の魚卵アレルゲン性の調査:全23個体の不妊化三倍体ニジマスの内臓組織に含まれるBCを測定したが、全個体の筋肉には魚卵アレルギー発症リスクが認められなかった。しかし、5個体において生殖線から少量のBCが検出されたが、その内3個体は目視にて明確な生殖腺の発達が観られた。目視で生殖線の発達が確認できなかった20個体について、生殖腺の組織切片を作製・観察し、その発達状況を確認した。その結果、3個体で発達中の卵母細胞が散在しているのが確認され、生殖腺の外観だけでアレルギー発症リスクの有無を見分けるのは困難であることが判明した。(清水、佐伯、笹岡、平松)
    日本学術振興会, 基盤研究(C), 北海道大学, 20K05903
  • 高性能紙デバイスの開発とその応用展開
    科学研究費助成事業
    2020年04月01日 - 2023年03月31日
    渡慶次 学, 谷 博文
    本研究では、①分析性能の高い紙デバイスの研究、②免疫分析デバイスの開発、③細胞アッセイ及び細胞分離デバイスの開発、④教育ツール用デバイスの開発に取り組む。本年度は、この中の①、②、④に取り組んだ。
    ①双極性障害の治療薬であるリチウム製剤の血中濃度測定をモデル系として、高性能紙デバイスシステムを構築した。血漿分離と血漿中のリチウムイオンの検出を性質の異なる紙を利用することで、わずか1滴(20マイクロリットル)の試料量で1分以内に測定することに成功した。検出性能は、遠心分離と吸光光度計による従来法と同等であった。
    ②競合免疫分析が可能な3次元紙デバイスを開発した。流路を3次元化することで流路長を短くすることが可能となり、アッセイ時間を短縮することができた。デバイスは3層構造になっており、反応領域と検出領域を別の層にすることで、分析性能を向上させることができた。さらに、非競合免疫分析の酵素免疫分析法(ELISA)の基礎検討も実施した。
    ③紙デバイスは、安価で簡便ということから、教育ツールとして適している。しかし、濃度定量するためには、マイクロピペットによる試料導入が必要である。そこでマイクロピペット等を用いずに、サンプルに浸漬するだけで、サンプル中の測定対象の濃度を定量できる紙デバイスを開発した。アスコルビン酸とpHの同時測定が可能なデバイスを開発し、測定結果の浸漬時間依存性を評価したところ、測定結果は浸漬時間(3秒から1分)に依存しないことも確認した。測定性能も従来法を同等であることを確認した。
    日本学術振興会, 基盤研究(B), 北海道大学, 20H02760
  • 国際連携によるハイブリッドエクソソーム創製に向けたコンバージェンス研究の展開
    科学研究費助成事業
    2019年10月07日 - 2023年03月31日
    加地 範匡, 渡慶次 学, 真栄城 正寿
    本国際共同研究では、日本・オランダ・シンガポールの各研究グループが独自に有するマイクロ・ナノテクノロジー、デバイス技術、エクソソーム分離・解析、エクソソーム高機能化、単一細胞アッセイ、細胞スフェロイドアッセイの各要素技術を結集して融合することで、再生医療やがん免疫療法に応用可能な高機能ハイブリッドエクソソームの創製を目的とする。本研究期間中、世界屈指の超微細加工技術とそれを可能とする施設を有するトウェンテ大学、基礎研究から臨床研究まで包括的に研究を行う体制が整っているシンガポール国立大学に若手研究者が3ヶ月以上滞在し、超微細加工技術から細胞スフェロイドアッセイ技術までを習得することで、エクソソームの選択的捕捉・分離・解析・高機能化から単一細胞・細胞スフェロイドアッセイが可能な統合型デバイスの研究開発をおこなうことを目指した。
    本研究の当初計画では、参画研究者がトウェンテ大学に長期滞在してデバイス作製技術の習得並びに作製と評価を行う予定であったが、昨年度に引き続いて今年度もコロナ禍のために海外渡航が叶わず、また国内での移動も多くの制限が課されていたため、オンラインディスカッションと各研究室で実施可能な基礎検討を中心に研究を行った。具体的には、外部バルス電界によるエクソソームへの外来物質導入やデバイスを用いた精製・評価法の検討を行い、最適な粒子濃度・電場強度を見出すとともに、長期保存における安定性についても評価を行った。その結果、牛乳由来エクソソームに関しては、粒子濃度が高く、電場強度が強いほど、外来物質の導入効率が高まることを明らかとした。また3ヶ月間の凍結保存においては、エクソソームの粒径などの正常に影響がないことも分かった。
    日本学術振興会, 国際共同研究加速基金(国際共同研究強化(B)), 九州大学, 19KK0140
  • オンサイト蛍光偏光イムノアッセイ装置の開発               
    先端計測分析技術・機器開発プログラム
    2016年10月 - 2021年03月
    渡慶次 学
    JST, 研究代表者, 競争的資金
  • マイクロチップによる同位体分離
    科学研究費助成事業
    2011年04月28日 - 2017年03月31日
    硲 隆太, 緒方 良至, 渡慶次 学, 三宅 亮, 佐久間 洋一
    1987年のノーベル賞となったクラウンエーテル(CE)を用い、その溶媒抽出法がイオンの分離だけでなく同位体分離にも適用出来ることを実証した。逆抽出法では、これまでの化学法による濃縮の中で最大の濃縮度(液液抽出3段目:LLE3で8%濃縮)の結果を得たが、Ca濃度は4段目以降は6桁落ちのため、多段化は実質困難であった。そこで、Ca濃度を維持(約2~3割減)し、高価なCE有機相を水のみで再生し繰り返し使用可能な新手法を開発した。このCa濃度(分配係数)と分離係数のトレードオフの関係は追認され、本新手法での分離係数は、1.0010±0.0003と逆抽出法の1/10となったが多段化への障壁はクリアした。
    日本学術振興会, 基盤研究(C), 23561013
  • 小型蛍光偏光測定デバイスの開発               
    科学研究費補助金挑戦的萌芽研究
    2012年 - 2015年03月
    渡慶次 学
    JSPS, 研究代表者, 競争的資金
  • 次世代診断チップの開発とその臨床診断への応用               
    科学研究費補助金基盤研究A
    2012年 - 2015年03月
    渡慶次 学
    JSPS, 研究代表者, 競争的資金
  • 半導体ナノ結晶と中空ファイバを活用した脳腫瘍の診断・治療一体型デバイスの開発
    科学研究費助成事業
    2011年04月01日 - 2014年03月31日
    水野 正明, 渡慶次 学, 岡本 行広, 朴 蓮洙, 湯川 博, 大森 雅登
    本研究では、悪性脳腫瘍の完治を目指し、MRI では検出できない腫瘍摘出腔の辺縁から1-3 cm の領域に残存する浸潤がん細胞を、細胞レベルで正確に検出し、取り除く技術の開発を行った。その結果、半導体ナノ結晶(トランスフェリン固定化量子ドット(QD-Tf))をリポソームに包埋し、中空ナノファイバーを活用することで脳腫瘍細胞の選択的高感度検出を可能にした。合わせて可視化に使用する半導体ナノ結晶から自由電子、ラジカル、イオン等を発生させ、細胞死を誘導する技術を確立し、診断・治療一体化医療デバイスの開発につながる基盤を作り上げた。
    日本学術振興会, 基盤研究(B), 名古屋大学, 23390346
  • MENDで拓く遺伝子治療への道:遺伝子の運び屋からナノマシンへ
    科学研究費助成事業
    2010年05月31日 - 2014年03月31日
    原島 秀吉, 山田 勇磨, 中村 孝司, 兵藤 守, 馬場 嘉信, 篠原 康雄, 小暮 健太朗, 紙谷 浩之, 渡慶次 学, 松尾 保孝, 秋田 英万
    パッチワーク法による新しいMEND構築方法を確立し一枚膜でコア粒子をパッケージする新しい方法を開発し、平均粒子径が25nm程度でゼータ電位が-40mV程度の構造体を得ることに成功し、P-MENDと命名した。D-MEND法と組み合わせることでPD- MEND(3枚膜構造)を構築したところ、市販の試薬より高い活性を示した。マイクロ流体デバイスを開発し、最小粒径30nmのMENDを作製することに成功した。一方でマイクロ流路作製についての検討し、ナノインプリント手法によりガラスマイクロ流路の量産が可能であることをしめした。また、シースフローと電場を利用したマイクロフリーフロー電気泳動デバイスの構造・分離条件の最適化を行い、MEND精製に適用することでMENDの定性的かつ定量的評価法を確立した。KALAペプチドを導入した脂質膜封入型ナノ粒子にがん抗原等をコードした遺伝子を封入することで、抗腫瘍活性を得ることに成功した。また、本粒子は細胞に対し免疫活性化効果を有することを示し、その機構に細胞質内DNAセンサーが関与することを示唆する結果を得た。酵素耐性RNAアプタマーの単離に世界で始めて成功した。Mt移行性ペプチドを搭載したMTS-MITO-Porterを構築し、生細胞内での選択的Mt送達システムを開発し、MTS-MITO-Porterは従来型MITO-Porterと比較してミトコンドリア移行能が飛躍的に上昇した。GAL4とVP16の融合蛋白質を用いる自己活性化システムを構築し、reporterプラスミドDNAの単独投与に比べて数十倍にルシフェラーゼ活性が上昇した。アンチセンスRNA (ASO)をMITO-Porterを用いて細胞Mtに送達し、ミトコンドリアmRNAを40%抑制し、さらに標的mRNAがコードする内因性Mtタンパク質の発現量が低下した。
    日本学術振興会, 基盤研究(S), 北海道大学, 22229001
  • 食品中の抗生物質検出のためのマイクロチップ蛍光偏光免疫分析法の開発               
    二国間交流事業
    2012年 - 2014年03月
    渡慶次 学
    JSPS, 研究代表者, 競争的資金
  • 超高性能マイクロチップ電気泳動による糖たんぱく質のアイソフォーム解析               
    二国間交流事業
    2011年 - 2013年03月
    渡慶次 学
    JSPS, 研究代表者, 競争的資金
  • 細胞アッセイ用マイクロデバイスの開発
    科学研究費補助金基盤研究B
    2008年 - 2011年03月
    渡慶次 学
    細胞培養から遺伝子発現解析までの一連のバイオアッセイが可能なマイクロバイオデバイスの開発を行った。浮遊性細胞(酵母)を培地交換をしながら還流培養を可能とするデバイスと、遺伝子解析(リアルタイムPCR)が可能な分析・解析デバイスを開発した。これら二つのデバイスを統合した統合デバイスを試作し、その性能評価・最適化を行い、当初目的を達成することに成功した。
    JSPS, 基盤研究(B), 名古屋大学, 研究代表者, 競争的資金, 20310072
  • 流路型免疫分析チップの開発               
    産業技術研究助成事業費助成金
    2007年 - 2011年03月
    渡慶次 学
    NEDO, 研究代表者, 競争的資金
  • エピジェネティクス解析のための1分子ゲノムDNAメチル化検出デバイスの開発
    科学研究費助成事業
    2008年 - 2011年
    馬場 嘉信, 渡慶次 学, 加地 範匡, 岡本 行広, 張 勇, 汪 俊, 安井 隆雄
    現状では達成不可能なPCR不要、超簡便、超高感度メチル化DNA検出方法の開発に成功した。具体的にはマイクロ・ナノデバイスにより単一DNA伸長方法を開発し、メチル化領域の高感度検出のために量子ドット-メチル化認識タンパク複合体の合成に成功した。これらを併用した手法の開発により現状では達成不可能な、PCR不要、簡便、超高感度かつ、メチル化部位の位置特定まで可能とする手法の開発に成功した。
    日本学術振興会, 基盤研究(A), 名古屋大学, 20241032
  • クラウンエーテル・マイクロチップ化学プラントによる二重ベータ崩壊同位元素濃縮
    科学研究費助成事業
    2007年 - 2010年
    硲 隆太, 岸本 忠史, 佐久間 洋一, 谷水 雅治, 渡慶次 学, 岸本 忠史, 佐久間 洋一, 谷水 雅治, 渡慶次 学
    ニュートリノの質量の絶対値及びマヨラナ性を検証できる二重ベータ崩壊は最も重要な研究の一つで、最大のQ値を持つ^<48>Caを含むCaF_2結晶300kgからなるCANDLES実験を近く開始する。Ca同位体濃縮はガスによる遠心・拡散分離法が不可でこれまで電磁法による高価で数十グラムの生産量に限られていた。我々は、クラウンエーテル液液抽出により化学法による濃縮の中で最大の分離係数1.012(常温20℃)~1.014(低温2℃)を得(Jepson(1.008)の約2倍、樹脂法(1.003)の約5倍)、気液2層同位体交換反応・乳化液滴形成マイクロチップにより抽出工程におけるマイクロチップの有効性を示した。
    日本学術振興会, 基盤研究(C), 広島大学, 19540300
  • 実診断を目指したマイクロチップ免疫分析システムの研究
    科学研究費補助金基盤研究B
    2006年 - 2009年03月
    渡慶次 学
    本研究では、平成17年度〜19年度の研究期間の中で、新しい3種のイムノアッセイシステムを構築した。平成17年度は、ビーズ表面に固定化した1次抗体を繰り返し使用することができる連続測定型酵素免疫(ELISA)分析システムを開発した。これにより、チップを交換することなく、連続測定が可能となった。平成18年度および19年度は、簡便かつ迅速、高感度、微量試料を実現した不均一系イムノアッセイシステムと、簡便かつ迅速な均一系医務の亜アッセイシステムを開発した。前者は、抗体を固定化した直径1μmのポリスチレンビーズと光硬化性樹脂を用いて、流路内にドット状の反応場を構築した流路を用いる。従来のビーズパック型の反応場とは異なり、流路内にドット状の反応場を作製することで、試料・試薬等の導入はキャピラリーフォースで行うことができ、簡便かつ迅速のアッセイが可能となった。これを用いてAFP(α-フェトプロテイン:腫瘍マーカー)の定量を行ったところ、分析時間約4分で1ng/mlの検出限界を実現した。アッセイに必要な試料量は僅か0.25μlである。後者は、溶液中で試料とキャプチャー抗体を反応させる不均一系イムノアッセイで、不均一系に比較すると分析時間が短いのが特徴である。マイクロフルイディクスによる高速混合と蛍光偏光検出を組み合わせることで、僅か1分程度でアッセイすることができ、信号のばらつきが小さく、再現性が高い。テオフィリン(気管支喘息の治療薬)をモデル試料して、本法の性能を評価したところ、良好な結果を得ることができた。
    JSPS, 基盤研究(B), 研究代表者, 競争的資金, 17310087
  • マイクロ・ナノ反応場を利用した革新的アクチノイド分離法の開発               
    原子力システム開発事業
    2005年 - 2008年03月
    渡慶次 学
    文部科学省, 研究代表者, 競争的資金
  • ファンクショナル熱レンズ顕微鏡               
    先端計測分析技術・機器開発事業
    2005年 - 2008年03月
    渡慶次 学
    JST, 研究代表者, 競争的資金
  • マイクロ空間における新規免疫化学反応場の創出               
    川崎市新技術・新製品開発等支援事業補助金
    2006年 - 2007年03月
    渡慶次 学
    川崎市, 研究代表者, 競争的資金
  • 心筋細胞の駆動力を電気エネルギーに変換するナノファイバー型バイオ発電素子の開発
    科学研究費補助金萌芽研究
    2004年 - 2006年03月
    渡慶次 学
    本研究は、生物の最小単位である細胞というパーツを用いて、微小機械及びナノ材料と結びつけるという全く新しい概念に基づいて、デバイス設計を行う斬新な試みである。これまでに様々なMEMSデバイス、発電素子、燃料電池が提案されてきたが、提案するデバイスは従来とは全く異なるアプローチによる独創的な新原理デバイスである。細胞と無機材料を融合させ、生体自ら発生するエネルギーやリズムを運動エネルギー、電気エネルギーに変換するという生体融合機能デバイスの創成である。
    そこで、心筋細胞を駆動源として、細胞を用いた柔らかいマイクロアクチュエータを実現できると考え,デバイスの設計及び基礎実験を行ってきた。細胞そのものを材料として、力学的機能と化学的機能を持ち合わせた新規なアクチュエータであり、構想及びデバイスの基本原理は非常に独創的である。基礎実験により、化学エネルギー(グルコース・酸素供給)だけで動作するアクチュエータを既に確認しており、試作したバイオマイクロアクチュエータの発生力は細胞あたり数nNから数十μNという大きな力を発生することが分かった。そこで、ナイロン糸上での心筋細胞の接着性をみるために,ナイロン糸上での心筋細胞培養実験を行った。ナイロン糸に接着している心筋細胞が観察でき,培養2日後には,拍動も確認できた。圧電ファイバーの伸縮応答実験より,心筋細胞を効率よくナイロン糸上に配向させることができれば,電圧が得られることがわかった。
    JSPS, 萌芽研究, (財)神奈川科学技術アカデミー, 研究代表者, 競争的資金, 16651081
  • マイクロチップを用いた再処理工場用分析装置の開発               
    革新的実用原子力技術開発費補助金
    2003年 - 2005年03月
    渡慶次 学
    経済産業省, 研究代表者, 競争的資金
  • 簡易型マイクロチップの実用化研究               
    基盤技術研究促進事業
    2001年 - 2004年03月
    渡慶次 学
    NEDO, 研究代表者, 競争的資金
  • 暗視野およびパームトップ熱レンズ顕微鏡の開発
    科学研究費助成事業
    2000年 - 2002年
    北森 武彦, 火原 彰秀, 久本 秀明, 渡辺 訓行, 渡慶次 学
    本研究は熱レンズ顕微鏡の更なる超高感度化と実用化を視野に入れ、暗視野光熱変換顕微鏡と可搬性の高いパームトップサイズ熱レンズ顕微鏡を開発することを目的とする。
    1.暗視野光熱変換顕微鏡の開発
    市販の生物顕微鏡を励起光と検出光の2本のレーザー光を導入できるように改良して、暗視野型光熱変換顕微鏡を作製した。作製した暗視野光熱変換顕微鏡を用いて励起光吸収用色素を内包したポリスチレン(80nm)粒子分散水を測定したところ、セル壁面で光が散乱され、原理的にバックグランドフリーである暗視野配置で高いバックグランド信号が発生していることがわかった。これを解決するために対物レンズと光検出器の間にピンホールユニットを作製し、セル壁面からの散乱光を排除して焦点付近からの光のみを通過・検出する(擬似共焦点配置)ようにした。これによりバックグランドを4桁低減することに成功した。
    2.パームトップサイズ熱レンズ顕微鏡の開発
    熱レンズ顕微鏡を小型化するためには、光源や光学系の小型化が必要である。熱レンズ顕微鏡の構成要素である励起光と検出光の焦点差を調整する機構と対物レンズを、色収差を持つ円筒形微小レンズに置き換えた新しい光学システムを設計し、作製した。既存のシステムと比較し、作製したシステムを評価したところ、小型レンズを用いた場合に特有のノイズが発生することを見いだした。今後、微小レンズ固定法の改良によりこのノイズを低減する予定である。
    日本学術振興会, 基盤研究(B), 東京大学, 12555233
  • マイクロチップを用いた高速高感度な内分泌拡散物質および関連物質の分析
    科学研究費助成事業
    2001年 - 2001年
    北森 武彦, 渡慶次 学, 木村 博子, 久本 秀明, 佐藤 記一
    マイクロチップを用いた高速高感度な内分泌撹乱物質および関連化合物の簡便迅速な分析システムを開発することを目標として、マイクロチップを用いたアッセイシステムの開発を行った。モデルケースとして小型海産巻き貝一個体中に微量含まれる性ホルモン17β-estradiolの定量を目標にした。
    数cm角のパイレックスガラス基板中に、深さ100μm、幅250μmで、中央部のみビーズをせき止めるために深さを10μmにしたマイクロチャネルを作製した。このチップに反応固相として直径15-50μm程度のポリスチレンビーズを導入し、ここに試料および各種試薬溶液を添加し、チップ内でそのまま抗原抗体反応および洗浄操作、酵素反応などを行った。生じた酵素反応生成物の検出には高感度な分析法である熱レンズ顕微鏡を用いた。
    作製したチップにあらかじめ抗17β-estradiol抗体を吸着させたビーズを導入した後、シリンジポンプを用いて17β-estradiolを含む試料と一定量のペルオキシダーゼ標識した17β-estradiolを混合した溶液を流し入れ、競合的に抗原抗体反応させた。未反応物を洗浄後、酵素基質を導入して酵素反応させ、そこで生成する発色物質を下流部で検出することにより定量を試みた。
    その結果、再現性はやや悪いものの、1-1,000pg/mLの比較的低濃度の濃度範囲で検量線を作成することが出来た。アッセイに必要な試料体積が極めて少量であることとあわせると、小型の巻き貝一個体からの抽出液から測定するのに充分な感度を有していることが明らかとなった。開発した方法では半日以上かかっていた分析を30分程度で終えることができ、分析時間の短縮も実現した。本システムは生体中の微量な環境ホルモン及び関連化合物の迅速簡便な分析手法として極めて有効な手法となることが期待できる。
    日本学術振興会, 特定領域研究(A), 東京大学, 13027219
  • 液相マイクロキャビティリングダウン分光法の開発と液相微小空間の超高感度検出
    科学研究費助成事業
    2000年 - 2001年
    渡慶次 学
    本年度は研究実施計画に基づけば、昨年度作製した微細流路(マイクロチャネル)を利用したキャビティ(多重反射セル)を用いてキャビティリングダウン(CRD)測定システムを評価する予定になっていた。しかし、昨年度作製したキャビティは測定条件を満足させるに至らなかったので、本年度の最初はキャビティの作製を行なった。
    1.キャビティの作製
    昨年度は、加熱式真空蒸着器でガラス基板にクロムを蒸着してキャビティを作製したが、クロムの膜厚にばらつきがあり、キャビティ表面で光散乱され、透過率が悪かった。そこで、本年度はスパッタリングによって、精密に膜厚を制御してガラス表面にクロム薄膜を作製した。これにより、キャビティ表面における光散乱が抑えられ、キャビティを作製することができた。
    2.測定システムの評価
    昨年度試作した顕微CRD測定システムを用いて液相CRD測定を行なった。試料はサンセットイエロー(色素)水溶液を用いた。キャビティ長が50〜100μmの場合、溶媒の散乱が大きく、測定はできなかった。キャビティ長が10μmの場合は、CRD信号が得られ、原理的に液相CRD測定が可能であることが実証できた。感度に関しては、吸光法とほとんど変わらず、今後キャビティ長をさらに短くするなどの改良を加えれば、高感度が可能だと考えられる。
    日本学術振興会, 奨励研究(A), (財)神奈川科学技術アカデミー, 12750720
  • 人工ナノメートル空間中液相分子の高速分光法および反応ダイナミクス制御法の開発
    科学研究費助成事業
    2000年 - 2001年
    北森 武彦, 火原 彰秀, 渡慶次 学
    本研究では、溶液を特長づけるの最小構成単位と考えられているクラスターの反応ダイナミクス計測を光熱変換分光法とマイクロチップ技術の利点を活用して実現することを目指している。溶液クラスターの大きさの数倍から数百倍の大きさと考えられる10〜数100nmの微小空間に液体を閉じこめ、測定することより、通常の大きさでは困難なバルク液体との情報を分離することを着想した。
    1.ナノ空間の作製 ナノ空間の作製には、電子線リソグラフィー・高速原子線加工法を用いた。また、溶液の導入路として幅190μmのチャネルをサンドブラストエッチングで作製した。ナノ空間として完成させるために、厚さ170μmの石英基板をふっ酸接合法にて接合した。溶液の導入には毛細管現象を利用する方法を利用した。ナノ空間として、幅330nm・深さ220nmの流路(330nm空間)・幅850nm・深さ620nmの流路(850nm空間)を、対照のバルク空間として幅250μm・深さ100μmの流路(250,000nm空間)を測定に用いた。
    2.蛍光寿命測定と空間サイズ効果 ローダミンB(RB)水溶液、スルホローダミン101(SR101)水溶液、ローダミン6G(R6G)水溶液を測定した。どの色素の場合もサイズに依存して波形が変化した。RBの場合には空間が小さくなるほど寿命が長くなり、SR101・R6Gの場合には、330nm空間のみ寿命が短くなることがわかった。寿命のサイズ依存は溶液の濃度にはほとんど依存せず、人工ナノ空間の溶媒物性を示していると考えられる。過去の文献等の知見より、SR101・R6Gの寿命の変化は誘電率変化に、RBの寿命変化は粘性変化に対応づけられると考えた。この変化の原因について、ガラス壁面の電荷などの影響により溶液クラスターの性質が顕在化してきているのではないかと考えられる。
    ナノメートルサイズの空間を人工的に加工し、その中で溶液の分光測定した例はこれまでになく、世界にさきがけナノ空間の液相化学が実現できたといえる。
    日本学術振興会, 特定領域研究(A), 東京大学, 12042218
  • ガラスチップに集積したミクロ生化学分析実験システムの構築と単一細胞生化学
    科学研究費助成事業
    1999年 - 2000年
    山崎 素直, 中尾 政之, 庄子 習一, 北森 武彦, 渡慶次 学, 木村 博子, 久本 秀明
    (財)神奈川科学技術アカデミーの研究開発プロジェクトと連携し、生化学分析をマイクロチャネル上で実現するために不可欠な要素技術を確立し、生化学分析へと応用した。本研究により、マイクロチップを用いた溶媒抽出とそれを利用したイオン分析、混合・反応を利用したフローインジェクション分析、レーザーを用いた反応温度制御と酵素反応解析、イムノアッセイ、超高感度検出器である熱レンズ顕微鏡と、その単一細胞イメージングへの応用などを実現した。
    マイクロチップ内の微小空間では分子拡散による移動距離が著しく短く、比界面積が大きいという特長があるため、溶媒抽出や溶液の混合が通常の実験系に比べて飛躍的に短い時間で分析することが可能であることを明らかにした。この現象を利用することにより、内径100ミクロンオーダーのマイクロチャネルを持つチップを用いてコバルトや鉄などの重金属イオンの湿式分析を従来法よりはるかに短い時間で実現することに成功した。加えて、チップ内部に固定した微小固相表面で行うイムノアッセイについても同様に効率よく短時間で分析可能であることを明らかにした。モデル試料の分析だけではなく、従来法では2日程度かかっていた腫瘍マーカーCEAの定量をわずか35分にまで短縮することができ、実際の患者血清を用いた分析において従来法と高い相関を得ることができ、実用性も高いと考えられる。
    一方チップ内で分析する場合には微小領域で測定可能な検出器が必要であり、それに適した超高感度検出器として熱レンズ顕微鏡を開発した。熱レンズ顕微鏡は1ミクロンオーダーの空間分解能で非蛍光性分子を単一分子レベルの高感度定量することが可能である。この特長を生かし、チップ内に培養した単一細胞内のシトクロームcのイメージングとアポトーシス過程における分布変化の計測に成功した。
    本研究をさらに発展させることによりマイクロチップはバイオ研究を飛躍的に発展させる新たな手法となると期待できる。
    日本学術振興会, 地域連携推進研究費, 東京大学, 11794006

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