Ishijima Ayumu

Research Institute for Electronic Science Biology and Life SciencesAssistant Professor
Last Updated :2025/06/07

■Researcher basic information

Researchmap personal page

Research Keyword

  • 超音波工学
  • 医用工学
  • 光工学

Educational Organization

■Career

Career

  • Dec. 2022 - Present
    Hokkaido University, 大学院情報科学院 情報科学専攻 生体情報工学コース, 助教
  • Sep. 2022 - Present
    Hokkaido University, Research Institute for Electronic Science, 助教
  • Jan. 2024 - Sep. 2024
    The University of Tokyo, The Graduate School of Engineering, 客員研究員
  • Sep. 2022 - Mar. 2023
    Japan Science and Technology Agency, さきがけ研究者(兼任)
  • Aug. 2020 - Sep. 2022
    The University of Tokyo, The Graduate School of Engineering, 特任助教
  • Oct. 2019 - Aug. 2022
    Japan Science and Technology Agency, さきがけ研究者(専任)
  • Apr. 2018 - Jul. 2020
    The University of Tokyo, The Graduate School of Engineering, 特任研究員
  • Apr. 2016 - Mar. 2018
    日本学術振興会, 特別研究員
  • Sep. 2013 - May 2014
    ライス大学Rebecca Richards-Kortum Lab, Visiting research scholar

Educational Background

  • Apr. 2015 - Mar. 2018, The University of Tokyo, The Graduate School of Engineering, Department of Precision Engineering
  • Apr. 2013 - Mar. 2015, The University of Tokyo, The Graduate School of Engineering, Department of Precision Engineering
  • Apr. 2009 - Mar. 2013, The University of Electro-Communications, Faculty of Electro-Communications, Department of Mechanical Engineering and Intelligent Systems

Committee Memberships

  • Apr. 2023 - Present
    応用物理学会北海道支部, 会計幹事, Society
  • Nov. 2024
    第60回応用物理学会北海道支部/第21回日本光学会北海道支部合同学術講演会, 実行委員
  • Jan. 2024
    第59回応用物理学会北海道支部/第20回日本光学会北海道支部合同学術講演会, 実行委員
  • 2024
    生体医工学シンポジウム, 大会実行委員
  • 2023
    The 24th RIES-HOKUDAI International Symposium, Organizing Committee
  • 2022
    The 23rd RIES-HOKUDAI International Symposium, Organizing Committee
  • 2022
    第31回ライフサポート学会フロンティア講演会, 大会実行委員
  • 2020
    16th Asian Conference on Computer Aided Surgery, Organizing Committee
  • 2019
    第58回日本生体医工学大会, 大会実行委員

■Research activity information

Awards

  • Sep. 2023, 日本生体医工学会, 生体医工学シンポジウムベストレビューワーアワード               
  • Mar. 2023, 応用物理学会, 第53回秋季応用物理学会講演奨励賞               
  • 2020, The IFMBE 11th Asian Pacific Conference on Medical and Biological Engineering, Young Investigator Award               
  • 2018, 東京大学, 工学系研究科長賞               
  • 2017, The 17th International Symposium on Therapeutic Ultrasound, Best Student Oral Presentation Award               
  • 2015, 東京大学 大学院工学系研究科 精密工学専攻, 優秀賞               
  • 2015, 日本生体医工学会関東支部若手研究者発表会, 優秀論文発表賞               
  • 2014, The 35th Symposium on Ultrasonic Electronics, Young Scientist Award               
  • 2013, 日本機械学会, 畠山賞               

Papers

  • Compact, widely tunable ultrashort burst pulse generator using four mirrors
    Rikako Tanaka, Keitaro Shimada, Ayumu Ishijima, Etsuko Kobayashi, Hideharu Mikami, Ichiro Sakuma, Keiichi Nakagawa
    Optics Letters, 01 May 2025
    Scientific journal
  • Numerical and Experimental Study of Spectrum Shuttle for Generating GHz Burst Pulses Without Sacrificing Spectral Ranges in Advanced Ultrafast Imaging
    K. Shimada, A. Ishijima, T. Saiki, I. Sakuma, Y. Inada, K. Nakagawa
    2024 Photonics North (PN), 1, 2, IEEE, 28 May 2024
    International conference proceedings
  • Single-shot optical imaging with spectrum circuit bridging timescales in high-speed photography
    Takao Saiki, Keitaro Shimada, Ayumu Ishijima, Hang Song, Xinyi Qi, Yuki Okamoto, Ayako Mizushima, Yoshio Mita, Takuya Hosobata, Masahiro Takeda, Shinya Morita, Kosuke Kushibiki, Shinobu Ozaki, Kentaro Motohara, Yutaka Yamagata, Akira Tsukamoto, Fumihiko Kannari, Ichiro Sakuma, Yuki Inada, Keiichi Nakagawa
    Science Advances, 22 Dec. 2023
    Scientific journal
  • Spectrum shuttle for producing spatially shapable GHz burst pulses
    Keitaro Shimada, Ayumu Ishijima, Takao Saiki, Ichiro Sakuma, Yuki Inada, Keiichi Nakagawa
    Advanced Photonics Nexus, 3, 01, SPIE-Intl Soc Optical Eng, 15 Dec. 2023
    Scientific journal
  • Cytosolic protein delivery using ultrasound‐guided vaporization of perfluorocarbon nano‐droplets
    Satoshi Yamaguchi, Miho Kisaka, Kotaro Higashi, Ayumu Ishijima, Takashi Azuma, Keiichi Nakagawa, Yoshikazu Shibasaki, Ichiro Sakuma, Akimitsu Okamoto
    Biotechnology Journal, Wiley, 07 May 2023
    Scientific journal
  • Measurement of angular correlation changes in double-photon emission nuclides using ultrasound irradiation
    F. Sensui, M. Uenomachi, K. Shimazoe, H. Takahashi, Z. Zhihong, A. Ishijima, K. Nakagawa
    Journal of Instrumentation, 18, 04, C04001, C04001, IOP Publishing, 01 Apr. 2023
    Scientific journal, Abstract

    Our group has been developing DPECT (Double Photon Emission CT) to enhance nuclear medicine diagnostics using cascade nuclides that emit multiple gamma rays simultaneously. It is possible to detect the local environment around the nuclide by examining the angular correlation of the emitted cascade gamma-rays. In this study, with the goal of developing a new imaging method combining ultrasound and nuclear medicine, we investigated the effect of ultrasound on cascade gamma-ray emission and found that the angular correlation could be changed by a micro-electric field around 111In in an aqueous solution caused by ultrasound irradiation. Using 8 × 8 array of GAGG scintillators as a detector and Hamamatsu Photonics 8 × 8 MPPCs as a photomultiplier, eight detectors were used and arranged in a ring shape to surround the point source 111In from 360° direction. For the readout system, using a dynamic ToT board, read out its channel information, energy information as ToT signal, and detection time information simultaneously and independently concerning gamma-ray detection. We measured the angular correlation change with four types of ultrasound intensities of 0.05 V, 0.10 V, 0.15 V, and 0.20 V input voltage, and found that the gamma-ray emission angle distribution decreased by about up to 5% around the 90° direction and increased by about up to 5% around 0° and 180° for an ultrasound with an input voltage of 0.15 V or higher.
  • Dispersive coherent Brillouin scattering spectroscopy
    Ayumu Ishijima, Shinga Okabe, Ichiro Sakuma, Keiichi Nakagawa
    Photoacoustics, Feb. 2023, [Lead author, Corresponding author]
    Scientific journal, Frequency- and time-domain Brillouin scattering spectroscopy are powerful
    tools to read out the mechanical properties of complex systems in material and
    life sciences. Indeed, coherent acoustic phonons in the time-domain method
    offer superior depth resolution and a stronger signal than incoherent acoustic
    phonons in the frequency-domain method. However, it does not allow multichannel
    detection and, therefore, falls short in signal acquisition speed. Here, we
    present Brillouin scattering spectroscopy that spans the time and frequency
    domains to allow the multichannel detection of Brillouin scattering light from
    coherent acoustic phonons. Our technique maps the time-evolve Brillouin
    oscillations at the instantaneous frequency of a chromatic-dispersed laser
    pulse. The spectroscopic heterodyning of Brillouin oscillations in the
    frequency domain enhances the signal acquisition speed by at least 100-fold
    over the time-domain method. As a proof of concept, we imaged heterogeneous
    thin films and biological cells over a wide bandwidth with nanometer depth
    resolution. We, therefore, foresee that our approach catalyzes future phonon
    spectroscopy toward real-time mechanical imaging.
  • Optical design of a laser wavefront sensor applicable under strong diffraction effects by irreproducible microscale high-density plasma
    Keitaro Shimada, Yuki Inada, Ayumu Ishijima, Keiichi Nakagawa
    MEASUREMENT SCIENCE AND TECHNOLOGY, 33, 5, May 2022
    English, Scientific journal
  • Acoustic frequency-dependent physical mechanism of sub-MHz ultrasound neurostimulation
    Haixiao Fan, Kenta Shimba, Ayumu Ishijima, Kenya Sasaoka, Tsuyoshi Takahashi, Chih-Hsiang Chang, Yasuhiko Jimbo, Takashi Azuma, Shu Takagi
    Japanese Journal of Applied Physics, Cold Spring Harbor Laboratory, 13 Sep. 2021, [Corresponding author]
    Scientific journal, Abstract

    Ultrasound is an innovative physical modality allowing non-invasive and reversible modulation of neural circuit activity in the brain with high spatial resolution. Despite growing interest in clinical applications, the safe and effective use of ultrasound neuromodulation has been limited by a lack of understanding of the physical mechanisms underlying its effects. Here, we demonstrate acoustic frequency-dependent physical effects that underlie ultrasound neuromodulation, where cavitation and radiation forces are the dominant sources of low- and high-frequency stimulation, respectively. We used 39.5 kHz and 500 kHz acoustic frequencies to stimulate cultured neural and glial cells, excised from rat cortex, to study acoustic frequency-dependent neural responses. We demonstrate increased evoked responses due to increased cavitation activity at the 39.5 kHz acoustic frequency. In contrast, notable cavitation activity was not detected at 500 kHz despite detection of evoked responses. Our work highlights the dependence of ultrasound neuromodulation on acoustic frequencies, with different physical effects underlying cell responses to low and high sub-MHz acoustic frequency ranges.
  • Acoustic light-sheet microscopy
    S. Wunderl, A. Ishijima, E. A. Susaki, Z. Xu, H. Song, H. Zha, T. Azuma, I. Sakuma, H. Fukuoka, E. Okada, H. R. Ueda, S. Takagi, K. Nakagawa
    Cold Spring Harbor Laboratory, 20 Aug. 2021
    Abstract

    Light-sheet imaging of 3D objects with high spatial resolution remains an open challenge because of the trade-off between field-of-view (FOV) and axial resolution originating from the diffraction of light. We developed acoustic light-sheet microscopy (acoustic LSM), which actively manipulates the light propagation inside a large sample to obtain wide-field microscopic images deep inside a target. By accurately coupling a light-sheet illumination pulse into a planar acoustic pulse, the light-sheet can be continuously guided over large distances. We imaged a fluorescence-labeled transparent mouse brain for the FOVs of 19.3 × 12.4 mm2 and 9.7 × 5.9 mm2 with resolved microstructures and single cells deep inside the brain. Acoustic LSM creates new opportunities for the application of light-sheet in the field of industry to basic science.

    One Sentence Summary

    An acoustic-optical method overcomes a trade-off between field-of-view and axial resolution in light-sheet microscopy.
  • Single-Shot Transmission Spectroscopic Imaging by Two-Color Stretched Pulses
    島田 啓太郎, 石島 歩, 佐伯 峻生, 佐久間 一郎, 稲田 優貴, 中川 桂一
    The review of laser engineering, 49, 4, 240, 244, レーザー学会, Apr. 2021
    Japanese, Scientific journal
  • Immunogenic Cell Death Induced by Selective Intracellular Vaporization in vitro
    Ayumu Ishijima, Satoshi Yamaguchi, Takashi Azuma, Etsuko Kobayashi, Kazuhiro Kakimi, Yoshikazu Shibasaki, Teruyuki Nagamune, Ichiro Sakuma
    IFMBE Proceedings, 82, 278, 283, Springer Science and Business Media Deutschland GmbH, 2021
    English, International conference proceedings
  • Cardiac macrophages prevent sudden death during heart stress
    Sugita, J., Fujiu, K., Nakayama, Y., Matsubara, T., Matsuda, J., Oshima, T., Liu, Y., Maru, Y., Hasumi, E., Kojima, T., Seno, H., Asano, K., Ishijima, A., Tomii, N., Yamazaki, M., Kudo, F., Sakuma, I., Nagai, R., Manabe, I., Komuro, I.
    Nature Communications, 12, 1, 1910, 1910, 2021, [International Magazine]
    English, Scientific journal
  • Spectrum Circuit for Producing Spectrally Separated Nanosecond Pulse Train in Free Space               
    Takao Saiki, Ayumu Ishijima, Ichiro Sakuma, Keiichi Nakagawa
    Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS, 2020-, Institute of Electrical and Electronics Engineers Inc., 01 May 2020
    English, International conference proceedings
  • Investigating the optimum size of nanoparticles for their delivery into the brain assisted by focused ultrasound-induced blood–brain barrier opening
    Ohta, S., Kikuchi, E., Ishijima, A., Azuma, T., Sakuma, I., Ito, T.
    Scientific Reports, 10, 1, Springer Science and Business Media LLC, 2020
    Scientific journal
  • Sequentially timed all-optical mapping photography boosted by a branched 4f system with a slicing mirror
    Saiki, T., Hosobata, T., Kono, Y., Takeda, M., Ishijima, A., Tamamitsu, M., Kitagawa, Y., Goda, K., Morita, S.-Y., Ozaki, S., Motohara, K., Yamagata, Y., Nakagawa, K., Sakuma, I.
    Optics Express, 28, 21, 31914, 31914, The Optical Society, 2020
    Scientific journal
  • Nonlinear photoacoustic waves for light guiding to deep tissue sites
    Ishijima, A., Yagyu, U., Kitamura, K., Tsukamoto, A., Sakuma, I., Nakagawa, K.
    Optics Letters, 44, 12, 2019
    Scientific journal
  • Selective intracellular delivery of perfluorocarbon nanodroplets for cytotoxicity threshold reduction on ultrasound-induced vaporization
    Ishijima, A., Yamaguchi, S., Azuma, T., Kobayashi, E., Shibasaki, Y., Nagamune, T., Sakuma, I.
    Cancer Reports, 2, 4, Wiley, 2019
    Scientific journal
  • Size-dependent delivery of nanoparticles to brain assisted by focused ultrasound-mediated BBB disruption
    Ohta Seiichi, Kikuchi Emi, Ishijima Ayumu, Kobayashi Etsuko, Azuma Takashi, Sakuma Ichiro, Ito Taichi
    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, 256, 19 Aug. 2018, [Peer-reviewed]
    International conference proceedings
  • Antibody-conjugated phase-change nano-droplet for ultrasound therapeutic agent
    Ayumu Ishijima, Shinya Yamahira, Satoshi Yamaguchi, Etsuko Kobayashi, Yoshikazu Shibasaki, Takashi Azuma, Teruyuki Nagamune, Ichiro Sakuma
    IEEE International Ultrasonics Symposium, IUS, IEEE Computer Society, 31 Oct. 2017, [Peer-reviewed]
    English, International conference proceedings
  • Survey on Preclinical Methods to Assess Collateral Thermal Damage to Tissues Caused by Surgical Devices
    Ishijima Ayumu, Koseki Yoshihiko, Azuma Takashi, Yamamoto Keisuke, Tateishi Keisuke, Chinzei Kiyoyuki, Sakuma Ichiro, Kobayashi Etsuko
    Journal of Japan Society of Computer Aided Surgery, 19, 2, 63, 73, The Japan Society of Computer Aided Surgery, 2017
    Japanese,

    Here we review the preclinical evaluation methodologies of thermal induced damage to tissues caused by surgical devices. Many innovative surgical devices based on thermal energy sources have been studied to offer less invasive treatment with fewer complications. Before these devices are used clinically, their safety must be validated using various methods to simulate the clinical situation with reasonable accuracy. We surveyed various preclinical studies and summarized methodologies to evaluate thermal induced damages. All the methodologies were categorized according to their invasiveness and measurement parameters (physical or biological parameters). In these studies, the damage was evaluated by one or more sub-assessments and attempted to clarify effective intensity and distribution of intervention to minimize the damage. For damage evaluation research, choice of techniques is extensive but decisions must be based on the nature of intervention.

  • Selective intracellular vaporisation of antibody-conjugated phase-change nano-droplets in vitro
    Ishijima, A., Minamihata, K., Yamaguchi, S., Yamahira, S., Ichikawa, R., Kobayashi, E., Iijima, M., Shibasaki, Y., Azuma, T., Nagamune, T., Sakuma, I.
    Scientific Reports, 7, 2017
    Scientific journal
  • PCNDの気泡化後の振る舞いと周囲温度の関係性について               
    菊池 健太朗, 田中 純, 石島 歩, 東 隆, 南畑 孝介, 山口 哲志, 長棟 輝行, 佐久間 一郎, 高木 周
    超音波医学, 43, 5, 677, 677, (公社)日本超音波医学会, Sep. 2016
    Japanese
  • The lifetime evaluation of vapourised phase-change nano-droplets
    Ayumu Ishijima, Jun Tanaka, Takashi Azuma, Kosuke Minamihata, Satoshi Yamaguchi, Etsuko Kobayashi, Teruyuki Nagamune, Ichiro Sakuma
    ULTRASONICS, 69, 97, 105, Jul. 2016
    English, Scientific journal
  • Preclinical Methods to Assess Collateral Mechanical Damage to Tissues Caused by Surgical Procedures and Devices
    Ishijima Ayumu, Koseki Yoshihiko, Ando Takehiro, Sakuma Ichiro, Kobayashi Etsuko
    Journal of Japan Society of Computer Aided Surgery, 18, 1, 19, 32, The Japan Society of Computer Aided Surgery, 2016
    Japanese, Many innovative surgical devices based on novel technologies and techniques have been studied to offer secure diagnosis and less invasive treatment with fewer complications. Before these devices are used clinically, their safety must be validated using various methods to simulate the clinical situation with reasonable accuracy. In this paper, we focused on mechanical intervention and surveyed various preclinical studies, which assessed the collateral damage accompanied with the use of these devices. This review paper is especially intended for a reader who (1) develops or researches on surgical devices, (2) intends to implement or commercialize innovative surgical devices or medical technologies to the society, and (3) wants to identify safety validation methods that are an index for surgical devices approval systematically. All studies were categorized according to their types of intervention (grasping, stretching, needle, and shock wave) so that the readers can efficiently find similar or related assessment methods. In these studies, the intervention was applied to a computer model and/or animal model in vivo and/or ex vivo. The damage was evaluated by one or more sub-assessments including tissue function and tissue structure as well as cellular functional and cellular structural assessments such as histological observations. Some of these studies attempted to clarify effective intensity and distribution of intervention, whose collateral damage was acceptably small. Therefore, such procedures or devices were proved to be effective and safe. Finally, considering all studies, we have tried to comment on the future challenges in this field.
  • ナノ液滴気泡化に周囲温度が与える影響の検討               
    田中 純, 石島 歩, 東 隆, 南畑 孝介, 山口 哲志, 長棟 輝行, 佐久間 一郎, 高木 周, 松本 洋一郎
    超音波医学, 42, 3, 374, 374, (公社)日本超音波医学会, May 2015
    Japanese
  • Automated frame selection process for high-resolution microendoscopy
    Ishijima, A., Schwarz, R.A., Shin, D., Mondrik, S., Vigneswaran, N., Gillenwater, A.M., Anandasabapathy, S., Richards-Kortum, R.
    Journal of Biomedical Optics, 20, 4, 2015
    Scientific journal

Other Activities and Achievements

  • 音波が操る生体試料中の光伝播
    石島 歩, Stefan WUNDERL, 宋 航, 中川 桂一, The review of laser engineering, 50, 2, 72, 76, Feb. 2022
    Japanese, Introduction scientific journal
  • Basic study on image reconstruction for wide-field imaging using len s array
    松下香穂, 富井直輝, 野田拓実, 島田啓太郎, 石島歩, 佐久間一郎, 堀崎遼一, 中川桂一, Optics & Photonics Japan講演予稿集(CD-ROM), 2022, 2022
  • Multi-frame single-shot ultrafast interferometry of laser-induced surface acoustic waves
    Takao Saiki, Keitaro Shimada, Ayumu Ishijima, Hang Song, Ichiro Sakuma, Keiichi Nakagawa, The International Conference on Ultrafast Phenomena (UP) 2022, 2022
    We developed a multi-frame single-shot ultrafast interferometry for quantitative measurements of dynamic phenomena. We observed laser-induced surface acoustic waves on a glass plate coated by 100 nm-thick chromium with 7 frames and 2.0 ns interval., Optica Publishing Group
  • 音響技術を用いた生体深部への光導波技術の現状と課題               
    石島歩, 中川桂一, 細胞, 54, 13, 53, 57, 2022
  • パルス音波と生体の相互作用に基づく光バイオ技術の創出
    宋 航, 佐伯 峻生, 石島 歩, 中川 桂一, Optical and electro-optical engineering contact, 59, 10, 45, 52, Oct. 2021
    光学工業技術協会, Japanese, Introduction commerce magazine
  • Magnetic Field Measurement using TMR Sensor for Catheter Tracking
    永野里奈, 赤木友紀, 中川桂一, 山崎正俊, 月原弘之, 石島歩, 小林英津子, 佐久間一郎, 大屋貴志, 精密工学会大会学術講演会講演論文集, 2020, 401, 402, 2020
    口腔癌治療のための超選択的動注化学放射線療法では挿入するカテーテルの位置ナビゲーションが求められており TMR 磁気式カテーテルトラッキングは有効である.本研究ではTMR センサの課題である狭い測定範囲を有効活用した磁場強度測定法の検討を行った.高サンプリングレート・低 SNR を実現するため過渡応答の情報から定常状態の磁場強度を推定する手法を提案し,6 個のコイルを 3 個ずつ時分割で駆動する事が有効である可能性を示した., The Japan Society for Precision Engineering, Japanese
  • In vivo light guiding with acoustic fields
    石島歩, 中川桂一, 細胞, 52, 2, 88, 92, 2020
    ニューサイエンス社, Japanese
  • 集束超音波照射による脳への薬物キャリア送達効率向上のサイズ依存性               
    太田 誠一, 菊地 映美, 石島 歩, 小林 英津子, 東 隆, 佐久間 一郎, 伊藤 大知, 日本DDS学会学術集会プログラム予稿集, 34回, 170, 170, May 2018
    日本DDS学会, Japanese
  • 集束超音波照射による脳への薬物キャリア送達効率向上のサイズ依存性
    太田 誠一, 菊地 映美, 石島 歩, 小林 英津子, 東 隆, 佐久間 一郎, 伊藤 大知, 日本DDS学会学術集会プログラム予稿集, 34回, 170, 170, May 2018
    日本DDS学会, Japanese
  • 金ナノ粒子を用いた超音波による血液脳関門透過性向上機構の検討
    菊地 映美, 石島 歩, 小林 英津子, 東 隆, 佐久間 一郎, 伊藤 大知, 太田 誠一, 日本バイオマテリアル学会大会予稿集, 39回, 146, 146, Nov. 2017
    日本バイオマテリアル学会, Japanese
  • 相変化ナノ液滴気泡化時の周囲温度調節による気泡寿命制御=相変化ナノ液滴気泡化の高速度撮影=
    石島歩, 東隆, 南畑孝介, 山口哲志, 小林英津子, 長棟輝行, 佐久間一郎, 超音波Techno, 28, 6, 89, 96, 2016
    日本工業出版, Japanese

Lectures, oral presentations, etc.

  • Increasing sensitivity of dispersive coherent Brillouin scattering spectroscopy by 4f pulse shaper               
    Ryo Okuyama, Ayumu Ishijima, Hideharu Mikami
    The 25th RIES-HOKUDAI International Symposium, 10 Dec. 2024, English, Poster presentation
  • ホログラフィック時空間集光によるリアルタイム3次元標的光刺激               
    高橋 瑛介, 石島 歩, 宍戸 耀, 広岡 隆, 米山 裕貴, 笠置 歩, 瀧 雅人, 冨菜 雄介, 澁川 敦史, 三上 秀治
    日本光学会年次学術講演会 Optics & Photonics Japan 2024, 29 Nov. 2024, Japanese, Oral presentation
  • 細胞のリアルタイム粘弾性計測に向けた分散コヒーレントブリルアン散乱分光法の高感度化               
    石島 歩, 奥山 亮, 三上 秀治
    第60回応用物理学会北海道支部/第21回日本光学会北海道支部合同学術講演会, 02 Nov. 2024, Japanese, Oral presentation
  • 4f波形整形器による分散コヒーレントブリルアン散乱分光法の高感度化               
    奥山亮, 石島歩, 三上秀治
    第59回応用物理学会北海道支部/第20回日本光学会北海道支部合同学術講演会, 06 Jan. 2024, Oral presentation
  • Opto-Acoustic Technology for Bioimaging               
    Ayumu Ishijima, Hideharu Mikami
    The 2023 RIES-CEFMS Joint International Symposium, 07 Dec. 2023, English, Poster presentation
  • Development of ultrafast multiphoton microscopy for large-scale, single-cell-resolution neural activity recording in the mouse brain               
    Eisuke Takahashi, Yuki Yoneyama, Ayumu Ishijima, Atsushi Shibukawa, Yusuke Tomina, Manami Kanamori, Koyo Kuze, Yuko Murakami, Suzu Oe, Takeshi Ishihara, Yu Toyoshima, Yuichi Iino, Hideharu Mikami
    The 24th RIES-HOKUDAI International Symposium, 06 Dec. 2023, Poster presentation
  • Proposal of a Fast 3D Multi-Cell Search and Tracking Algorithm using Random Access Focusing and Its Validation by Numerical Simulation               
    Ryu Hirooka, Yuki Yoneyama, Ayumu Ishijima, Atsushi Shibukawa, Hideharu Mikami
    The 24th RIES-HOKUDAI International Symposium, 06 Dec. 2023, Poster presentation
  • 〔Major achievements〕音響光技術とバイオイメージング               
    石島 歩
    日本光学会光エレクトロニクス産学連携専門委員会第337回研究会, 04 Dec. 2023
    [Invited]
  • 〔Major achievements〕ブリルアン散乱光の空間多重化計測によるバイオイメージング               
    石島 歩
    Optics & Photonics Japan 2023(レーザ顕微鏡研究会ジョイントシンポジウム), 28 Nov. 2023
    [Invited]
  • 3Dランダムアクセス集光による高速多細胞探索・追跡アルゴリズムの実験的検証               
    米山裕貴、広岡隆、石島歩、澁川敦史、三上秀治
    日本光学会年次学術講演会 Optics & Photonics Japan 2023, 27 Nov. 2023, Poster presentation
  • 3Dランダムアクセス集光による高速多細胞探索・追跡アルゴリズムの提案と数値シミュレーションによる検証               
    広岡隆, 米山裕貴, 石島歩, 澁川敦史, 三上秀治
    日本光学会年次学術講演会 Optics & Photonics Japan 2023, 27 Nov. 2023, Poster presentation
  • マウスの脳神経活動計測の大規模化に向けた超高速多光子励起蛍光顕微鏡法の開発               
    高橋瑛介, 米山裕貴, 石島歩, 澁川敦史, 三上秀治
    第9回北海道大学部局横断シンポジウム, 11 Oct. 2023, Poster presentation
  • 3Dランダムアクセス集光による高速多細胞探索・追跡法の実験的検証               
    米山裕貴, 広岡隆, 石島歩, 澁川敦史, 三上秀治
    第9回北海道大学部局横断シンポジウム, 11 Oct. 2023, Poster presentation
  • 音響光技術のバイオイメージングへの展開               
    石島歩, 冨菜雄介, 澁川敦史, 三上秀治
    日本学術会議公開シンポジウム「光がもたらす未来社会~ICOの新たな発展に向けて~」, 10 Jul. 2023, Poster presentation
  • 〔Major achievements〕ライトシートブリルアン散乱顕微法の原理実証               
    石島歩, 岡部真我, 佐久間一郎, 中川桂一
    第70回応用物理学会春季学術講演会, 15 Mar. 2023, Invited oral presentation
    [Invited]
  • ライトシートブリルアン散乱顕微法の提案と実証               
    石島歩, 岡部真我, 中川桂一, 佐久間一郎
    第83回応用物理学会秋季学術講演会, 20 Sep. 2022
  • 〔Major achievements〕Dispersive coherent Brillouin scattering spectroscopy for biomaterial characterization               
    Ayumu Ishijima
    International Conference on Materials Science, Engineering & Technology 2022, 09 Sep. 2022, English, Invited oral presentation
    [Invited]
  • 〔Major achievements〕超音波刺激による神経細胞活動誘発に対するキャビテーションの影響について               
    高木周, 石島歩, 範海嘯, 榛葉健太, 神保泰彦
    日本超音波医学会第95回学術集会, 21 May 2022, Invited oral presentation
    [Invited]
  • Development of virtual optical waveguide: numerical analysis of focusing underwater shock waves               
    Tetsuro Ikeyama, Hiroshi Fukuoka, Keiichi Nakagawa, Ayumu Ishijima
    The 32th International Symposium on Transport Phenomena, English, Oral presentation
    19 Mar. 2022 - 21 Mar. 2022
  • Multi-frame single-shot ultrafast interferometry of laser-induced surface acoustic waves
    Takao Saiki, Keitaro Shimada, Ayumu Ishijima, Hang Song, Ichiro Sakuma, Keiichi Nakagawa
    The International Conference on Ultrafast Phenomena (UP) 2022, 2022, Optica Publishing Group, English, Oral presentation
    2022 - 2022, We developed a multi-frame single-shot ultrafast interferometry for quantitative measurements of dynamic phenomena. We observed laser-induced surface acoustic waves on a glass plate coated by 100 nm-thick chromium with 7 frames and 2.0 ns interval.
  • Proposal of ultrafast laser diffractometry for analyzing bubble dynamics with sub-diffraction-limit resolution               
    瀬川拓未, 石島歩, 佐伯峻生, 島田啓太郎, SONG Hang, 山口哲志, 佐久間一郎, 小林英津子, 中川桂一
    衝撃波シンポジウム講演論文集(CD-ROM), 2022
    2022 - 2022
  • Acoustic Wave Manipulates Light Propagation Inside Biological Sample               
    石島歩, 石島歩, WUNDERL Stefan, SONG Hang, 中川桂一
    レーザー研究, 2022
    2022 - 2022, [Invited]
  • Measurement of Angular Correlation Changes in Double-Photon Emission Nuclides Using Ultrasound irradiation               
    Fumiki Sensui, Mizuki Uenomachi, Kenji Shimazoe, Zhihong Zhong, Ayumu Ishijima, Keiichi Nakagawa, Hiroyuki Takahashi
    22nd International Workshop on Radiation Imaging Detectors, 29 Jun. 2021
  • Development of an electromagnetic catheter tracking system using TMR sensor for superselective intra-arterial chemotherapy.               
    Rina Nagano, Kazuaki Hara, Ayumu Ishijima, Naoki Tomii, Keiichi Nakagawa, Yuki Akagi, Masatoshi Yamazaki, Hiroyuki Tsukihara, Etsuko Kobayashi, Takashi Ohya, Ichiro Sakuma
    Computer Assisted Radiology and Surgery 2021, Jun. 2021
  • Electron density imaging of ultrafast plasma dynamics with two-color STAMP               
    Keitaro Shimada, Yuki Inada, Ayumu Ishijima, Takao Saiki, Ichiro Sakuma, Keiichi Nakagawa
    OPIC OPTICS & PHOTONICS International Congress 2021, 19 Apr. 2021
  • 〔Major achievements〕音響波による生体試料中の光伝播操作               
    石島歩, Stefan Wunderl, 中川桂一
    レーザー学会学術講演会第41回年次大会, 18 Jan. 2021, Invited oral presentation
    [Invited]
  • Basic study on time-stretch Brillouin spectroscopy for high-speed elasticity measurement               
    岡部真我, 石島歩, 石島歩, 中川桂一, 佐久間一郎
    Optics & Photonics Japan講演予稿集(CD-ROM), 2021
    2021 - 2021
  • Nanosecond single-shot imaging system with a picosecond exposure time for monitoring the shock wave effects on cells               
    佐伯峻生, 石島歩, QI Xinyi, 塚本哲, 佐久間一郎, 中川桂一
    衝撃波シンポジウム講演論文集(CD-ROM), 2021
    2021 - 2021
  • Focusing Behavior of Underwater Shock Wave Utilizing Elliptical Cell               
    伊東聡, 池山哲良, 福岡寛, 矢尾匡永, 石島歩, 中川桂一
    衝撃波シンポジウム講演論文集(CD-ROM), 2021
    2021 - 2021
  • A Studies on Angular Correlation Changes of Double-Photon Emission Nuclides Using Ultrasound               
    泉水史樹, 上ノ町水紀, 島添健次, 高橋浩之, ZHONG Zhihong, 石島歩, 中川桂一
    日本原子力学会春の年会予稿集(CD-ROM), 2021
    2021 - 2021
  • 〔Major achievements〕Immunogenic cell death induced by selective intracellular vaporization in vitro               
    Ayumu Ishijima, Satoshi Yamaguchi, Takashi Azuma, Etsuko Kobayashi, Kazuhiro Kakimi, Yoshikazu Shibasaki, Teruyuki Nagamune, Ichiro Sakuma
    The IFMBE 11th Asian Pacific Conference on Medical and Biological Engineering, 26 May 2020, Oral presentation
  • Spectrum circuit for producing spectrally separated nanosecond pulse train in free space               
    Takao Saiki, Ayumu Ishijima, Ichiro Sakuma, Keiichi Nakagawa
    2020 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO), 2020, English
    2020 - 2020
  • Development of experimental system for elucidating the physical effects of shock waves on cells               
    佐伯峻生, QI Xinyi, 石島歩, 塚本哲, 佐久間一郎, 中川桂一
    衝撃波シンポジウム講演論文集(CD-ROM), 2020
    2020 - 2020
  • Development of an optical system to investigate the relationship between pressure wave with different wavelengths and cell response               
    GAO Hemeng, 石島歩, 佐伯峻生, 塚本哲, 中川桂一, 佐久間一郎
    衝撃波シンポジウム講演論文集(CD-ROM), 2020
    2020 - 2020
  • Behavior of Underwater Shockwave in Elliptical Cell               
    伊東聡, 福岡寛, 石島歩, 中川桂一
    衝撃波シンポジウム講演論文集(CD-ROM), 2020
    2020 - 2020
  • Magnetic Field Measurement using TMR Sensor for Catheter Tracking
    永野里奈, 赤木友紀, 中川桂一, 山崎正俊, 月原弘之, 石島歩, 小林英津子, 佐久間一郎, 大屋貴志
    精密工学会大会学術講演会講演論文集, 2020, The Japan Society for Precision Engineering, Japanese
    2020 - 2020, 口腔癌治療のための超選択的動注化学放射線療法では挿入するカテーテルの位置ナビゲーションが求められており TMR 磁気式カテーテルトラッキングは有効である.本研究ではTMR センサの課題である狭い測定範囲を有効活用した磁場強度測定法の検討を行った.高サンプリングレート・低 SNR を実現するため過渡応答の情報から定常状態の磁場強度を推定する手法を提案し,6 個のコイルを 3 個ずつ時分割で駆動する事が有効である可能性を示した.
  • Optical waveguide inside tissues by laser-induced nonlinear acoustic wave               
    石島歩, 柳生右京, 北村憲太, 佐久間一郎, 中川桂一
    Optics & Photonics Japan講演予稿集(CD-ROM), 2019
    2019 - 2019
  • 相変化ナノ液滴を用いた細胞質内タンパク質デリバリー技術の開発               
    山口哲志, 山口哲志, 木坂美穂, 石島歩, 東隆, 柴崎芳一, 佐久間一郎, 岡本晃充
    化学工学会年会研究発表講演要旨集(CD-ROM), 2019
    2019 - 2019
  • スライスミラーの超精密加工とイメージングシステムへの応用
    佐伯 峻生, 佐久間 一郎, 中川 桂一, 細畠 拓也, 河野 志洋, 竹田 真宏, 石島 歩, 森田 晋也, 尾崎 忍夫, 本原 顕太郎, 山形 豊
    精密工学会学術講演会講演論文集, 2019, 公益社団法人 精密工学会, Japanese
    2019 - 2019,

    分光イメージングに用いられるスライスミラーは,その特殊形状から作製が難しい.本研究では,切削によるスライスミラーの加工を行い,表面粗さと形状および回折光の評価を行った.その結果,一次試作品では工具破損由来で表面に高さ約2.5μmの凹凸がみられ回折光が発生したが,二次試作品では,表面粗さRa < 10 nm, 形状誤差PV < 100 nm, ミラー幅誤差 < ±100 μm,面角度誤差 < ±0.025°という要求仕様を満足し,回折光の発生を抑えることができた.

  • Size-dependent delivery of nanoparticles to brain assisted by focused ultrasound-mediated BBB disruption               
    Seiichi Ohta, Emi Kikuchi, Ayumu Ishijima, Etsuko Kobayashi, Takashi Azuma, Ichiro Sakuma, Taichi Ito
    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, Aug. 2018, AMER CHEMICAL SOC, English
    Aug. 2018 - Aug. 2018
  • 超音波照射による粒径に依存した金ナノ粒子の血液脳関門透過のin vitro,in vivo評価               
    菊地映美, 石島歩, 小林英津子, 東隆, 東隆, 佐久間一郎, 伊藤大知, 伊藤大知, 太田誠一
    化学工学会年会研究発表講演要旨集(CD-ROM), 2018
    2018 - 2018
  • 集束超音波照射による脳への薬物キャリア送達効率向上のサイズ依存性               
    太田誠一, 菊地映美, 石島歩, 小林英津子, 東隆, 東隆, 佐久間一郎, 伊藤大知, 伊藤大知
    日本DDS学会学術集会プログラム予稿集, 2018
    2018 - 2018
  • 超音波照射による粒径に依存したナノ粒子の血液脳関門透過のin vivo評価と数理モデル化               
    太田誠一, 菊地映美, 石島歩, 小林英津子, 東隆, 東隆, 佐久間一郎, 伊藤大知, 伊藤大知
    日本膜学会年会講演要旨集, 2018
    2018 - 2018
  • 相変化ナノ液滴を用いた細胞質内タンパク質導入               
    木坂美穂, 山口哲志, 石島歩, 東隆, 小林英津子, 柴崎芳一, 長棟輝行, 佐久間一郎, 岡本晃充, 岡本晃充
    日本化学会春季年会講演予稿集(CD-ROM), 2018
    2018 - 2018
  • 相変化ナノ液滴を用いた細胞質内タンパク質導入               
    木坂美穂, 山口哲志, 石島歩, 小林英津子, 東隆, 長棟輝行, 柴崎芳一, 佐久間一郎, 岡本晃充, 岡本晃充
    高分子学会予稿集(CD-ROM), 2018
    2018 - 2018
  • 超音波を用いたナノ粒子の血液脳関門透過性向上のin vitro評価               
    菊地映美, 石島歩, 小林英津子, 東隆, 東隆, 佐久間一郎, 伊藤大知, 伊藤大知, 太田誠一
    化学工学会大会(Web), 2017
    2017 - 2017
  • 抗体修飾相変化ナノ液滴による選択的細胞内気泡化               
    石島歩, 東隆, 南畑孝介, 山口哲志, 山平真也, 小林英津子, 飯島麻里子, 柴崎芳一, 長棟輝行, 佐久間一郎
    超音波医学, 2017
    2017 - 2017
  • 超音波照射による金ナノ粒子の血液脳関門透過性向上とその粒径依存性               
    太田誠一, 菊地映美, 石島歩, 小林英津子, 東隆, 東隆, 佐久間一郎, 伊藤大知, 伊藤大知
    膜シンポジウム, 2017
    2017 - 2017
  • 金ナノ粒子を用いた超音波による血液脳関門透過性向上機構の検討               
    菊地映美, 石島歩, 小林英津子, 東隆, 東隆, 佐久間一郎, 伊藤大知, 伊藤大知, 太田誠一
    日本バイオマテリアル学会大会予稿集(Web), 2017
    2017 - 2017
  • 超音波セラノスティクスを志向した相変化ナノ液滴の化学修飾               
    木坂美穂, 山口哲志, 東昂太郎, 石島歩, 東隆, 柴崎芳一, 佐久間一郎, 岡本晃充, 岡本晃充
    日本化学会春季年会講演予稿集(CD-ROM), 2017
    2017 - 2017
  • Mechanism of sonodynamic therapy: radical formation as 'activation' of dye-sensitizer
    Ishijima Ayumu, Azuma Takashi, Yamahira Shinya, Kobayashi Etsuko, Nagamune Teruyuki, Sakuma Ichiro, Kawabat Kenichi
    Transactions of Japanese Society for Medical and Biological Engineering, 2017, Japanese Society for Medical and Biological Engineering, Japanese
    2017 - 2017,

    While sonodynamic therapy is a promising double-targeting cancer therapeutic, its mechanisms are still unclear. We hypothesized that cytotoxic effect of sonodynamic therapy is due to sensitizer radicals generated by electron transfers from cavitation-induced hydroxyl radicals to dye-sensitizers. Carbon-centered radicals derived from dye-sensitizer is expected to proceed oxidation of cellular membrane with high efficiency than hydroxyl radicals because those have longer lifetime than hydroxyl radicals. Here we demonstrated that cytotoxic effect of AAPH derived oxygen-centered radicals to cultured tumour cells was enhanced by presence of Ce6, a typical well-known dye for photo and sonodynamic therapy. In vitro experiments showed that cytotoxic efficacy of 100 mM AAPH was enhanced more than 20-fold in presence of Ce6. Furthermore, phthalocyanine tetrasulfonate, a photosensitizer that possess electronically stable chemical structure, did not enhance cytotoxic efficacy of AAPH. As a future work, we will investigate whether cytotoxic effect by ultrasound exposure is similar trend as AAPH.

  • PCNDの気泡化後の振る舞いと周囲温度の関係性について               
    菊池健太朗, 田中純, 石島歩, 東隆, 南畑孝介, 山口哲志, 長棟輝行, 佐久間一郎, 高木周
    超音波医学, 2016
    2016 - 2016
  • ナノ液滴気泡化に周囲温度が与える影響の検討               
    田中純, 石島歩, 東隆, 南畑孝介, 山口哲志, 長棟輝行, 佐久間一郎, 高木周, 松本洋一郎
    超音波医学, 2015
    2015 - 2015
  • 1J2-1 Lifetime Control of Vaporized Nano Droplets Using Ambient Temperature Conditioning
    Tanaka Jun, Kikuchi Kentaro, Ishijima Ayumu, Azuma Takashi, Minamihata Kosuke, Yamaguchi Satoshi, Nagamune Teruyuki, Sakuma Ichiro, Takagi Shu
    Proceedings of Symposium on Ultrasonic Electronics, 2015, Institute for Ultrasonic Elecronics, English
    2015 - 2015
  • Automated frame selection process for analyzing high resolution microendoscope images
    Ayumu Ishijima, Sharon Mondrik, Richard A. Schwarz, Nadarajah Vigneswaran, Ann M. Gillenwater, Rebecca Richards-Kortum
    TRANSLATIONAL BIOPHOTONICS, 2014, English
    2014 - 2014
  • 2P5-4 Optically and acoustically simultaneous measurement of phase change nano-droplet vaporization(Poster Session)
    Ishijima Ayumu, Tanaka Jun, Azuma Takashi, Maezawa Miyuki, Ando Takehiro, Kobayashi Etsuko, Sakuma Ichiro
    Proceedings of Symposium on Ultrasonic Electronics, 2014, Institute for Ultrasonic Elecronics, English
    2014 - 2014

Courses

  • 情報エレクトロニクス演習(分担)               
    北海道大学工学部情報エレクトロニクス学科
    Apr. 2023 - Present
  • 生体情報工学実験Ⅰ(分担)               
    北海道大学工学部情報エレクトロニクス学科
    Apr. 2023 - Present
  • Freshman Seminar               
    Hokkaido University
    Apr. 2023 - Present
  • 生体情報工学特別演習(分担)               
    北海道大学 大学院情報科学院 情報科学専攻 生体情報工学コース
    2022 - Present
  • English Exercise for Science and Technology               
    Hokkaido University
    2022 - Present
  • Bioinformatics ExperimentsⅡ               
    Hokkaido University
    2022 - Present
  • Introduction to Nanotechnology and Nanoscience I               
    Hokkaido University
    2023

Affiliated academic society

  • Jan. 2022 - Present
    応用物理学会               

Research Themes

  • 高強度音響フォノンによる非接触・非標識・非侵襲バイオイメージング技術の開発               
    自転車等機械振興事業
    Apr. 2025 - Mar. 2026
    公益財団法人JKA, Principal investigator, 2025M-440
  • 新奇分光手法による高速高感度バイオイメージング
    科学研究費助成事業 基盤研究(B)
    01 Apr. 2022 - 31 Mar. 2025
    石島 歩
    日本学術振興会, 基盤研究(B), 東京大学, 22H03933
  • バイオイメージングのための超音波時空間制御手法と高感度検出手法の開発
    科学研究費助成事業
    Jun. 2023 - Mar. 2025
    石島 歩
    日本学術振興会, 挑戦的研究(萌芽), 北海道大学, 23K18584
  • コヒーレント音響フォノンによる力学特性の高速バイオイメージング               
    基礎科学研究助成
    Nov. 2023 - Nov. 2024
    公益財団法人 住友財団, Principal investigator, 2300191
  • コヒーレント音響フォノンの時空間多重化計測で切り拓く細胞力学ダイナミクス               
    研究助成
    Jul. 2023 - Jun. 2024
    石島歩
    公益財団法人村田学術振興財団, 北海道大学, Principal investigator
  • 超高速音響光技術開発               
    文部科学省全国共同利用・共同研究拠点制度
    Apr. 2023 - Mar. 2024
    中川桂一, 石島歩
    物質・デバイス領域共同研究拠点, 基盤共同研究, 東京大学, Others, 20231008
  • 光駆動非線形音響波による生体深部メカノイメージング               
    戦略的創造研究推進事業
    2019 - 2023
    科学技術振興機構(JST), さきがけ
  • Research on a mechanism of ultrasonic mechanotransduction by high-speed strain measurement
    Grants-in-Aid for Scientific Research
    01 Apr. 2019 - 31 Mar. 2022
    Ishijima Ayumu
    While the effectiveness of ultrasonic neuromodulation has been demonstrated in recent years, it is not clear why ultrasound induces mechanotransduction. The main motivation of this study was to clarify the appropriate physical quantities to induce the target biological phenomenon by ultrasound in order to elucidate the mechanism of ultrasonic neuromodulation. As a result of the research, the physical mechanism of the acoustic frequency dependence of ultrasonic stimulation in the sub-MHz region was clarified. In the low-frequency range of ultrasonic stimulation, we found that cavitation evoked cultured neuron cells activity. On the other hand, no significant cavitation activity was detected in the high-frequency range, suggesting that the acoustic radiation force may evoke neural activity.
    Japan Society for the Promotion of Science, Grant-in-Aid for Early-Career Scientists, The University of Tokyo, 19K20662
  • 選択的細胞内気泡化による非侵襲超音波がん治療法の開発
    科学研究費助成事業 研究活動スタート支援
    24 Aug. 2018 - 31 Mar. 2020
    石島 歩
    申請者は,2017年に超音波応答性抗がん薬「標的化PCND (Phase-change nano-droplet)」を用いた非侵襲超音波がん治療技術「選択的細胞内気泡化」を提案し, in vitroでの原理検証結果を発表した.これは抗腫瘍効果が機械的作用という,これまでに無い作用機序により治療を行う薬剤である.本研究課題では,これを臨床応用可能な治療技術として発展させるべく,担癌マウスモデルを用いた有効性の検証に挑んだ.具体的な達成目標として,超音波照射系と二光子イメージング系が統合された実験系を構築し,標的化PCNDの血中から腫瘍への蓄積,気泡化前後における細胞の変化,免疫系の応答を明らかにすることを掲げた.
    本年度は二光子イメージングシステムに統合可能な超音波照射系の構築に取り組んだ.超音波照射系は,顕微鏡システムに容易に搭載可能な,4本の振動子が組みこまれた小型水槽とした.この超音波照射系を設計,構築し,音場をハイドロフォンとシュリーレンイメージングにより評価した結果,音波の集束が確認でき,最大負圧で4 MPaの圧力の出力が可能であることを示した.さらに,この超音波照射系を自作の明視野顕微鏡システムに組み込み,超音波照射により惹起される物理現象の可視化を行った.具体的には,アクリルアミドゲル中に固定したマイクロバブルに超音波を照射し,その振動を高速度撮影した.
    本研究で開発した超音波照射システムを今後,二光子顕微鏡に組み込み,PCND気泡化により引き起こされる生命現象を明らかにしていく予定である.
    日本学術振興会, 研究活動スタート支援, 東京大学, 18H05956
  • 抗体修飾型相変化ナノ液滴と超音波を用いた細胞選択的診断治療の開発
    科学研究費助成事業 特別研究員奨励費
    22 Apr. 2016 - 31 Mar. 2018
    石島 歩
    細胞の中での気泡化と細胞の外での気泡化による傷害作用を比較することにより,細胞内に相変化ナノ液滴を導入する利点を示した.具体的には気泡化に伴う傷害作用を引き起こす超音波の音圧値が低下することを示した.さらに細胞内気泡化により傷害した細胞の免疫原性を評価し,本手法によって引き起こされる細胞死の免疫原性が高いことを示した.下記に具体的な内容について示す.


    抗体修飾された相変化ナノ液滴(9E5修飾PCND)を抗体抗原反応により細胞内に選択的に導入することで液滴同士の凝集が共焦点顕微鏡観察により確認された.9E5修飾PCNDをDLD1細胞(抗原発現がん細胞)に作用させてから1hでは,細胞内における9E5修飾PCND由来の蛍光シグナルは検出されなかったが,細胞膜に介入している9E5修飾PCNDが観察された.9E5修飾PCNDを細胞に作用させてから3hでは,細胞内に移行している9E5修飾PCNDが観察され,6hでは,細胞内移行が顕著であった.24h経過すると,細胞内の数か所で9E5 修飾PCND からの高い蛍光輝度値が検出された.PCNDの細胞内凝集を引き起こした状態とそうでない状態において,超音波照射を行い,生存率測定を行うと,凝集を引き起こした状態において,細胞を傷害するために要する超音波強度が低かった.このことから細胞内に相変化ナノ液滴を導入することで,気泡化による傷害閾値を低下できることを示した.


    また,細胞内気泡化により引き起こされた細胞死において,ATPとHMGB1の細胞外への放出が確認された.これらの物質はDAMPs(damage associated molecular patterns)として知られ,免疫原性を有する.このことから,本手法によって引き起こされる細胞死の免疫原性が高いことが示された.
    日本学術振興会, 特別研究員奨励費, 東京大学, 16J09959

Industrial Property Rights

  • 超音波医療装置
    Patent right, 江幡 定生, 東 隆, 佐久間 一郎, 高木 周, 石島 歩, 田中 純, オリンパス株式会社, 国立大学法人 東京大学
    JP2015081070, 04 Nov. 2015
    WO2017-077605, 11 May 2017
    201803000418045243

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