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Nishida Erika

Faculty of Dental Medicine　Division of Dental Medicine　Department of Health ScienceAssistant Professor
Hokkaido University HospitalAssistant Professor

Researcher basic information

■ Degree
  • DDS, Ph.D, Hokkaido University, Mar. 2016
■ URL
researchmap URLホームページURL■ Various IDs
Researcher number
  • 50779882
J-Global ID■ Research Keywords and Fields
Research Field
  • Life Science, Conservative dentistry
■ Educational Organization

Career

■ Career
Educational Background
  • 北海道大学大学院, 歯学研究院, Japan

Research activity information

■ Papers
  • Zinc-addition route as a key parameter for forming an antibacterial apatite layer on dentin by a laser-assisted biomimetic process
    Kazuo Onuma; Miyabi Makino; Maki Nakamura; Erika Nishida; Kanako Shitomi; Hirofumi Miyaji; Ayako Oyane
    Surfaces and Interfaces, Sep. 2026
    Scientific journal
  • Antibacterial crystalline bilayers constructed on dentin substrates via laser-assisted mineralization: characterization and functional implications
    Kazuo Onuma; Miyabi Makino; Maki Nakamura; Erika Nishida; Kanako Shitomi; Saori Tanaka; Hirofumi Miyaji; Ayako Oyane
    Applied Surface Science, Dec. 2025
    Scientific journal
  • Sema3A-and ascorbate-functionalized apatite-collagen scaffolds for enhanced bone regeneration
    Kaushita Banerjee; Hanae Ishii; Ayako Oyane; Maki Nakamura; Tomoya Inose; Erika Nishida; Kari Tsukita; Tomoka Hasegawa; Hirofumi Miyaji
    MRS COMMUNICATIONS, 21 Aug. 2025
    English, Scientific journal
  • Integration of dual drugs into a collagen scaffold by a combination of apatite coating and impregnation with apatite particles for periodontal regeneration.
    Kaushita Banerjee; Ayako Oyane; Maki Nakamura; Tomoya Inose; Erika Nishida; Kanako Shitomi; Hirofumi Miyaji
    RSC advances, 15, 24, 19480, 19488, 04 Jun. 2025, [International Magazine]
    English, Scientific journal, Bioresorbable porous scaffolds capable of promoting osteoregeneration while preventing bacterial infection are needed for regenerative periodontal therapy. Previously, a porous collagen sponge coated with low-crystalline apatite has been shown to possess superior bioresorption and osteogenic properties compared to the uncoated sponge. In this study, we integrated osteogenic and antibacterial dual drugs into the sponge utilizing two types of apatite matrices to achieve further functionalization. First, the collagen sponge was coated with apatite loaded with an osteogenic drug, l-ascorbic acid 2-phosphate (AS), using a metastable supersaturated calcium phosphate (CaP) solution supplemented with AS. Second, the coated sponge was impregnated with apatite particles loaded with an antibacterial drug, ciprofloxacin (CF), which were fabricated using a labile supersaturated CaP solution supplemented with CF. The resulting dual drug-immobilized sponge demonstrated biological activities arising from both AS and CF; it enhanced proliferation of osteoblastic MC3T3-E1 cells and exhibited antibacterial activity against the oral bacterium Actinomyces naeslundii. The proposed technique to fabricate multifunctional scaffolds would offer a solution to provide more effective, patient-tailored regenerative periodontal therapy.
  • 酸化グラフェン超薄膜と口腔洗浄含嗽剤による抗菌性耐水コーティング
    西田 絵利香; 金本 佑生実; 石井 花英; 郷田 隼; 宮治 裕史
    日本歯科保存学雑誌, 68, 3, 103, 112, (NPO)日本歯科保存学会, Jun. 2025
    Japanese
  • 【抗菌性・抗ウイルス性バイオマテリアル アップデート】酸化グラフェン超薄膜の導入による抗菌剤の基材定着性の向上
    宮治 裕史; 西田 絵利香; 郷田 隼; 川崎 英也
    バイオマテリアル-生体材料-, 43, 2, 152, 157, 日本バイオマテリアル学会, Apr. 2025
    Japanese
  • Fluoride-incorporated apatite coating on resin-based composite via laser-assisted rapid pseudo-biomineralization
    Nandha Kumar Ponnusamy; Ayako Oyane; Maki Nakamura; Tomoya Inose; Kazuo Onuma; Erika Nishida; Hirofumi Miyaji
    Applied Surface Science, Feb. 2025, [Peer-reviewed]
    Scientific journal
  • Antimicrobial Water-resistant Coating Method by Compositing Graphene Oxide Ultrathin Film and Mouthwash Solution
    西田絵利香; 金本佑生実; 石井花英; 郷田隼; 宮治裕史
    日本歯科保存学雑誌(Web), 68, 3, 2025
  • Ultrafast coating of fluoride-substituted hydroxyapatite layers on teeth by laser-assisted crystallization: Comparison of surface structure and composition among enamel, dentin, and cementum
    Kazuo Onuma; Miyabi Makino; Ikuko Sakamaki; Maki Nakamura; Erika Nishida; Saori Tanaka; Hirofumi Miyaji; Ayako Oyane
    Applied Surface Science, 674, 15 Nov. 2024, [Peer-reviewed]
    English, Scientific journal
  • Fabrication of Ciprofloxacin-Immobilized Calcium Phosphate Particles for Dental Drug Delivery.
    Aniruddha Pal; Ayako Oyane; Tomoya Inose; Maki Nakamura; Erika Nishida; Hirofumi Miyaji
    Materials (Basel, Switzerland), 17, 9, 26 Apr. 2024, [Peer-reviewed], [International Magazine]
    English, Scientific journal, Calcium phosphate (CaP) particles immobilizing antibacterial agents have the potential to be used as dental disinfectants. In this study, we fabricated CaP particles with immobilized ciprofloxacin (CF), a commonly prescribed antibacterial agent, via a coprecipitation process using a supersaturated CaP solution. As the aging time in the coprecipitation process increased from 2 to 24 h, the CaP phase in the resulting particles transformed from amorphous to low-crystalline hydroxyapatite, and their Ca/P elemental ratio, yield, and CF content increased. Despite the higher CF content, the particles aged for 24 h displayed a slower release of CF in a physiological salt solution, most likely owing to their crystallized matrix (less soluble hydroxyapatite), than those aged for 2 h, whose matrix was amorphous CaP. Both particles exhibited antibacterial and antibiofilm activities along with an acid-neutralizing effect against the major oral bacteria, Streptococcus mutans, Porphyromonas gingivalis, and Actinomyces naeslundii, in a dose-dependent manner, although their dose-response relationship was slightly different. The aging time in the coprecipitation process was identified as a governing factor affecting the physicochemical properties of the resulting CF-immobilized CaP particles and their functionality as a dental disinfectant.
  • Fluoride-Incorporated Apatite Coating on Collagen Sponge as a Carrier for Basic Fibroblast Growth Factor.
    Aniruddha Pal; Ayako Oyane; Maki Nakamura; Kenji Koga; Erika Nishida; Hirofumi Miyaji
    International journal of molecular sciences, 25, 3, 25 Jan. 2024, [Peer-reviewed], [International Magazine]
    English, Scientific journal, Coating layers consisting of a crystalline apatite matrix with immobilized basic fibroblast growth factor (bFGF) can release bFGF, thereby enhancing bone regeneration depending on their bFGF content. We hypothesized that the incorporation of fluoride ions into apatite crystals would enable the tailored release of bFGF from the coating layer depending on the layer's fluoride content. In the present study, coating layers consisting of fluoride-incorporated apatite (FAp) crystals with immobilized bFGF were coated on a porous collagen sponge by a precursor-assisted biomimetic process using supersaturated calcium phosphate solutions with various fluoride concentrations. The fluoride content in the coating layer increased with the increasing fluoride concentration of the supersaturated solution. The increased fluoride content in the coating layer reduced its solubility and suppressed the burst release of bFGF from the coated sponge into a physiological salt solution. The bFGF release was caused by the partial dissolution of the coating layer and, thus, accompanied by the fluoride release. The concentrations of released bFGF and fluoride were controlled within the estimated effective ranges in enhancing bone regeneration. These findings provide useful design guidelines for the construction of a mineralized, bFGF-releasing collagen scaffold that would be beneficial for bone tissue engineering, although further in vitro and in vivo studies are warranted.
  • Water-resistant antibacterial properties of a graphene oxide/cetylpyridinium chloride complex formed on medical gauze fibers.
    Yukimi Kanemoto; Hirofumi Miyaji; Erika Nishida; Asako Hamamoto; Tsutomu Sugaya; Syun Gohda; Hironobu Ono
    Journal of oral biosciences, 65, 2, 202, 205, Jun. 2023, [Peer-reviewed], [International Magazine]
    English, Scientific journal, OBJECTIVES: Graphene oxide (GO) is a nanocarbon material with a high aspect ratio (width:thickness) and abundant anionic functional groups on its surface. In this study, we attached GO to the surface of medical gauze fibers, constructed a complex with a cationic surface active agent (CSAA), and demonstrated that the treated gauze exhibits antibacterial activity even after rinsing with water. METHODS: Medical gauze was immersed in GO dispersion (0.001%, 0.01%, and 0.1%), rinsed with water, dried, and subjected to the Raman spectroscopy analysis. Subsequently, the gauze treated with 0.001% GO dispersion was immersed in 0.1% cetylpyridinium chloride (CPC) solution, immediately rinsed with water, and dried. Untreated, GO-only, and CPC-only gauzes were prepared for comparison. Each gauze was placed in a culture well, seeded with Escherichia coli or Actinomyces naeslundii, and turbidity was measured after 24 h of incubation. RESULTS: The Raman spectroscopy analysis of the gauze after immersion and rinsing showed a G band peak, indicating that GO remained on the surface of the gauze. The turbidity measurements indicated that GO/CPC-treated gauze (GO-treated and rinsed, followed by CPC-treatment and rinsing) significantly decreased turbidity compared to the other gauzes (P < 0.05), suggesting that the GO/CPC complex remained on the gauze fibers even after water rinsing and showed antibacterial activity. CONCLUSIONS: The GO/CPC complex imparts water-resistant antibacterial properties to gauze and has the potential to be widely used for the antimicrobial treatment of clothes.
  • 酸化亜鉛ユージノール系ペーストタイプ根管充填シーラーの材料特性ならびに生体親和性評価
    加藤 昭人; 宮治 裕史; 金本 佑生実; 蔀 佳奈子; 岡本 一絵; 吉野 友都; 浜本 朝子; 西田 絵利香; 菅谷 勉; 田中 佐織
    日本歯科保存学雑誌, 66, 2, 114, 123, (NPO)日本歯科保存学会, Apr. 2023
    Japanese
  • Periodontal tissue regeneration by recombinant human collagen peptide granules applied with β-tricalcium phosphate fine particles.
    Yuto Yoshino; Hirofumi Miyaji; Erika Nishida; Yukimi Kanemoto; Asako Hamamoto; Akihito Kato; Tsutomu Sugaya; Tsukasa Akasaka
    Journal of oral biosciences, 65, 1, 62, 71, Mar. 2023, [Peer-reviewed], [International Magazine]
    English, Scientific journal, OBJECTIVES: Recombinant human collagen peptide (RCP) is a recombinantly created xeno-free biomaterial enriched in arginine-glycine-aspartic acid sequences with good processability whose use for regenerative medicine applications is under investigation. The biocompatibility and osteogenic ability of RCP granules combined with β-tricalcium phosphate (TCP) submicron particles (β-TCP/RCP) were recently demonstrated. In the present study, β-TCP/RCP was implanted into experimental periodontal tissue defects created in beagles to investigate its regenerative effects. METHODS: An RCP solution was lyophilized, granulated, and thermally cross-linked into particles approximately 1 mm in diameter. β-TCP dispersion (1 wt%; 500 μL) was added to 100 mg of RCP granules to form β-TCP/RCP. A three-walled intrabony defect (5 mm × 3 mm × 4 mm) was created on the mesial side of the mandibular first molar and filled with β-TCP/RCP. RESULTS: A micro-computed tomography image analysis performed at 8 weeks postoperative showed a significantly greater amount of new bone after β-TCP/RCP grafting (2.2-fold, P < 0.05) than after no grafting. Histological findings showed that the transplanted β-TCP/RCP induced active bone-like tissue formation including tartaric acid-resistant acid phosphatase- and OCN-positive cells as well as bioabsorbability. Ankylosis did not occur, and periostin-positive periodontal ligament-like tissue formation was observed. Histological measurements performed at 8 weeks postoperative revealed that β-TCP/RCP implantation formed 1.7-fold more bone-like tissue and 2.1-fold more periodontal ligament-like tissue than the control condition and significantly suppressed gingival recession and epithelial downgrowth (P < 0.05). CONCLUSIONS: β-TCP/RCP implantation promoted bone-like and periodontal ligament-like tissue formation, suggesting its efficacy as a periodontal tissue regenerative material.
  • Rose bengal-decorated rice husk-derived silica nanoparticles enhanced singlet oxygen generation for antimicrobial photodynamic inactivation.
    Nanase Mori; Hideya Kawasaki; Erika Nishida; Yukimi Kanemoto; Hirofumi Miyaji; Junko Umeda; Katsuyoshi Kondoh
    Journal of materials science, 58, 6, 2801, 2813, 2023, [Peer-reviewed], [International Magazine]
    English, Scientific journal, UNLABELLED: Rice husks are well known for their high silica content, and the RH-derived silica nanoparticles (RH NPs) are amorphous and biocompatible; therefore, they are suitable raw materials for biomedical applications. In this study, rose bengal-impregnated rice husk nanoparticles (RB-RH NPs) were prepared for their potential photosensitization and 1O2 generation as antimicrobial photodynamic inactivation. RB is a halogen-xanthene type's photosensitizer showing high singlet oxygen efficiency, and the superior photophysical properties are desirable for RB in the antimicrobial photodynamic inactivation of bacteria. To enhance the binding of anionic RB to RH NPs, we conducted cationization for the RH NPs using polyethyleneimine (PEI). The control of the RB adsorption state on cationic PEI-modified RH NPs was essential for RB RH-NP photosensitizers to obtain efficient 1O2 generation. Minimizing RB aggregation allowed highly efficient 1O2 production from RB-RH NPs at the molar ratio of RB with the PEI, XRB/PEI. = 0.1. The RB-RH NPs have significant antimicrobial activity against Streptococcus mutans compared to free RB after white light irradiation. The RB-RH NP-based antimicrobial photodynamic inactivation can be employed effectively in treating Streptococcus mutans for dental applications. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10853-023-08194-z.
  • In vivo Assessment of Tissue Compatibility of Root Canal Sealer Containing Surface Pre-reacted Glass-ionomer Fillers
    Saori TANAKA; Hirofumi MIYAJI; Kayoko MAYUMI; Yukimi K ANEMOTO; Erika NISHIDA
    Operative Dentistry, Endodontology and Periodontology, 2, 1, 33, 39, Dec. 2022, [Peer-reviewed]
    English, Scientific journal
  • Sustained antibacterial coating with graphene oxide ultrathin film combined with cationic surface-active agents in a wet environment.
    Hirofumi Miyaji; Yukimi Kanemoto; Asako Hamamoto; Kanako Shitomi; Erika Nishida; Akihito Kato; Tsutomu Sugaya; Saori Tanaka; Natsuha Aikawa; Hideya Kawasaki; Syun Gohda; Hironobu Ono
    Scientific reports, 12, 1, 16721, 16721, 18 Oct. 2022, [Peer-reviewed], [International Magazine]
    English, Scientific journal, Antimicrobial surfactants contained in mouthrinse have excellent efficacy, but are not retained on the tooth surface (are rinsed away) due to their low water resistance and thus do not exhibit sustained antibacterial activity. We have developed a new coating method using graphene oxide (GO) that retains the surfactant on the tooth surface even after rinsing with water, thus providing a sustained antibacterial effect. Ultra-thin films of GO and an antimicrobial agent were prepared by (1) applying GO to the substrate surface, drying, and thoroughly rinsing with water to remove excess GO to form an ultrathin film (almost a monolayer, transparent) on the substrate surface, then (2) applying antimicrobial cationic surface active agents (CSAAs) on the GO film to form a composite coating film (GO/CSAA). GO/CSAA formation was verified by scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and ζ-potential and contact angle measurements. GO/CSAA was effective at inhibiting the growth of oral pathogens for up to 7 days of storage in water, and antibacterial activity was recovered by reapplication of the CSAA. Antibacterial GO/CSAA films were also formed on a tooth substrate. The results suggest that GO/CSAA coatings are effective in preventing oral infections.
  • Fabrication and cell behavior assessment of antibacterial micro/nano-patterned chitosan films
    Erika NISHIDA; Hirofumi MIYAJI; Tsutomu SUGAYA; Tsukasa AKASAKA
    Nano Biomedicine, 14, 1, 1, 8, 2022, [Peer-reviewed], [Lead author]
    English
  • Periodontal tissue engineering using an apatite/collagen scaffold obtained by a plasma- and precursor-assisted biomimetic process.
    Yukimi Kanemoto; Hirofumi Miyaji; Erika Nishida; Saori Miyata; Kayoko Mayumi; Yuto Yoshino; Akihito Kato; Tsutomu Sugaya; Tsukasa Akasaka; Arputharaj Joseph Nathanael; Syama Santhakumar; Ayako Oyane
    Journal of periodontal research, 57, 1, 205, 218, Jan. 2022, [Peer-reviewed], [International Magazine]
    English, Scientific journal, BACKGROUND AND OBJECTIVES: In the treatment of severe periodontal destruction, there is a strong demand for advanced scaffolds that can regenerate periodontal tissues with adequate quality and quantity. Recently, we developed a plasma- and precursor-assisted biomimetic process by which a porous collagen scaffold (CS) could be coated with low-crystalline apatite. The apatite-coated collagen scaffold (Ap-CS) promotes cellular ingrowth within the scaffold compared to CS in rat subcutaneous tissue. In the present study, the osteogenic activity of Ap-CS was characterized by cell culture and rat skull augmentation tests. In addition, the periodontal tissue reconstruction with Ap-CS in a beagle dog was compared to that with CS. METHODS: The plasma- and precursor-assisted biomimetic process was applied to CS to obtain Ap-CS with a low-crystalline apatite coating. The effects of apatite coating on the scaffold characteristics (i.e., surface morphology, water absorption, Ca release, protein adsorption, and enzymatic degradation resistance) were assessed. Cyto-compatibility and the osteogenic properties of Ap-CS and CS were assessed in vitro using preosteoblastic MC3T3-E1 cells. In addition, we performed in vivo studies to evaluate bone augmentation and periodontal tissue reconstruction with Ap-CS and CS in a rat skull and canine furcation lesion, respectively. RESULTS: As previously reported, the plasma- and precursor-assisted biomimetic process generated a low-crystalline apatite layer with a nanoporous structure that uniformly covered the Ap-CS surface. Ap-CS showed significantly higher water absorption, Ca release, lysozyme adsorption, and collagenase resistance than CS. Cell culture experiments revealed that Ap-CS was superior to CS in promoting the osteoblastic differentiation of MC3T3-E1 cells while suppressing their proliferation. Additionally, Ap-CS significantly promoted (compared to CS) the augmentation of the rat skull bone and showed the potential to regenerate alveolar bone in a dog furcation defect. CONCLUSION: Ap-CS fabricated by the plasma- and precursor-assisted biomimetic process provided superior promotion of osteogenic differentiation and bone neoformation compared to CS.
  • Antibacterial coating of tooth surface with ion-releasing pre-reacted glass-ionomer (S-PRG) nanofillers.
    Kayoko Mayumi; Hirofumi Miyaji; Saori Miyata; Erika Nishida; Tomokazu Furihata; Yukimi Kanemoto; Tsutomu Sugaya; Kanako Shitomi; Tsukasa Akasaka
    Heliyon, 7, 2, e06147, Feb. 2021, [Peer-reviewed], [International Magazine]
    English, Scientific journal, OBJECTIVES: Surface pre-reacted glass-ionomer (S-PRG) fillers release antibacterial borate and fluoride ions. We fabricated nanoscale S-PRG fillers (S-PRG nanofillers) for antibacterial coating of tooth surfaces and assessed the antibacterial effects of this coating in vitro. In addition, we creating a canine model of periodontitis to evaluate the effectiveness of S-PRG nanofiller application on tooth roots and improvement of periodontal parameters. METHODS: Human dentin blocks were coated with S-PRG nanofiller (average particle size: 0.48 μm) and then characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDX), and ion-releasing test. Antibacterial effects of dentin blocks coated with S-PRG nanofiller were examined using bacterial strains, Streptococcus mutans and Actinomyces naeslundii. Next, we created an experimental model of periodontitis in furcation of premolars of beagle dogs. Then, S-PRG nanofiller coating was applied onto exposed tooth root surfaces. Periodontal parameters, gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment level (CAL), were measured from baseline until 4 weeks. In addition, bone healing was radiographically and histologically examined. RESULTS: SEM and EDX revealed that S-PRG nanofillers uniformly covered the dentin surface after coating. Dentin blocks coated with S-PRG nanofiller showed ion-releasing property, bacterial growth inhibition, and sterilization effects. In the experimental periodontitis model, S-PRG nanofiller coating significantly reduced clinical inflammatory parameters, such as GI (P < 0.01) and BOP (P < 0.05), compared to uncoated samples. In addition, PPD and CAL significantly decreased by S-PRG nanofiller coating (2 weeks: P < 0.05; 3 and 4 weeks: P < 0.01), suggesting the improvement of periodontitis. Micro-CT and histology revealed that bone healing of furcation defects was enhanced by S-PRG nanofiller coating. CONCLUSION: S-PRG nanofiller coating provides antibacterial effects to tooth surfaces and improves clinical parameters of periodontitis.
  • Evaluation of antibacterial and cytocompatible properties of multiple-ion releasing zinc-fluoride glass nanoparticles.
    Erika Nishida; Hirofumi Miyaji; Kanako Shitomi; Tsutomu Sugaya; Tsukasa Akasaka
    Dental materials journal, 40, 1, 157, 164, 31 Jan. 2021, [Peer-reviewed], [Domestic magazines]
    English, Scientific journal, Zinc-fluoride glass nanoparticles (Zinc-F) release several ions, such as fluoride, zinc and calcium ions, through acid-base reactions. The aim of this study was to evaluate the antibacterial and cytotoxic properties of Zinc-F. Antibacterial tests showed that a Zinc-F eluting solution significantly reduced the turbidity and colony-forming units of Streptococcus mutans and Actinomyces naeslundii, compared to that of calcium-fluoroaluminosilicate glass nanoparticles without zinc ions. In live/dead staining, Zinc-F eluate significantly decreased green-stained bacterial cells, indicating live cells, compared with the control (no application). Human dentin coated with Zinc-F showed suppressed S. mutans and A. naeslundii biofilm formation. Additionally, Zinc-F eluate showed low cytotoxic effects in osteoblastic and fibroblastic cells. Therefore, our findings suggested that Zinc-F exhibits antibacterial and biocompatible properties through multiple-ion release.
  • Bone forming ability of recombinant human collagen peptide granules applied with β-tricalcium phosphate fine particles.
    Tomokazu Furihata; Hirofumi Miyaji; Erika Nishida; Akihito Kato; Saori Miyata; Kanako Shitomi; Kayoko Mayumi; Yukimi Kanemoto; Tsutomu Sugaya; Tsukasa Akasaka
    Journal of biomedical materials research. Part B, Applied biomaterials, 108, 7, 3033, 3044, Oct. 2020, [Peer-reviewed], [International Magazine]
    English, Scientific journal, Recombinant human collagen peptide, developed based on human collagen type I, contains an arginyl-glycyl-aspartic acid (RGD)-rich motif to enhance cell behavior and is anticipated as a xeno-free polymer material for use in tissue engineering. We fabricated granules containing recombinant human collagen peptide (RCP) applied with beta-tricalcium phosphate fine particles (RCP/β-TCP) as bone filling scaffold material and assessed the bone forming ability of RCP/β-TCP. Recombinant peptide was thermal crosslinked and freeze-dried to prepare RCP. An aqueous dispersion of β-TCP fine particles was added to RCP to obtain RCP/β-TCP. Subsequently, RCP/β-TCP were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), and cell culture assessments. Furthermore, RCP/β-TCP were implanted into rat cranial bone defects for radiographic and histological evaluations. In SEM and EDX analyses of RCP/β-TCP, β-TCP particles dose-dependently covered the surface of RCP. Cell culture tests showed that RCP/β-TCP remarkably promoted proliferation and mRNA expression of various genes, such as integrin β1 and osteogenic markers, of osteoblastic MC3T3-E1 cells. Histomorphometric assessment at 4 weeks showed that RCP/β-TCP significantly promoted new skull bone formation compared to RCP (p < 0.05) and control (no application) (p < 0.01). Accordingly, these findings suggest RCP/β-TCP possess bone forming capability and would be beneficial for bone tissue engineering therapy.
  • Comparative biological assessments of endodontic root canal sealer containing surface pre-reacted glass-ionomer (S-PRG) filler or silica filler.
    Hirofumi Miyaji; Kayoko Mayumi; Saori Miyata; Erika Nishida; Kanako Shitomi; Asako Hamamoto; Saori Tanaka; Tsukasa Akasaka
    Dental materials journal, 39, 2, 287, 294, 31 Mar. 2020, [Peer-reviewed], [Domestic magazines]
    English, Scientific journal, Surface pre-reacted glass-ionomer (S-PRG) filler releases several ions, such as fluoride, borate and strontium ions, to exert bioactive effects. We fabricated an endodontic root canal sealer containing S-PRG fillers (S-PRG sealer) and then evaluated the antibacterial and anti-inflammatory properties of S-PRG sealer compared with sealer containing conventional silica fillers (silica sealer). Antibacterial tests showed that S-PRG sealer significantly reduced the turbidity of Enterococcus faecalis compared with silica sealer. Implantation of S-PRG or silica sealer blocks in rat subcutaneous tissue showed that S-PRG sealer decreased the proinflammatory response compared with silica sealer at 10 days post-implantation. In addition, immunostaining revealed that infiltration of CD68- and peroxidase-positive cells around the S-PRG sealer was significantly lower than that in silica sealer. Therefore, it was suggested that S-PRG sealer exhibits antibacterial and anti-inflammatory effects.
  • Human Dentin Coated with Silver Nanoclusters Exhibits Antibacterial Activity against Streptococcus mutans
    Shitomi Kanako; Miyaji Hirofumi; Miyata Saori; Nishida Erika; Mayumi Kayoko; Sugaya Tsutomu; Kawasaki Hideya
    Nano Biomedicine, 11, 1, 21, 28, ナノ・バイオメディカル学会, Jun. 2019, [Peer-reviewed]
    English, 虫歯の病原菌であるStreptococcus mutansに対して審美的(象牙質変色予防)作用と抗菌的作用を持つ成分として、直径2nm未満の銀ナノクラスター(AgNC)を調製した。このAgNCはS.mutansの濁度と生存性を顕著に減少させるだけでなく、LIVE/DEAD染色法にて殺菌効果が認められた。このAgNCをヒト象牙質に適用すると、フッ化ジアミン銀を適用した場合と比べて象牙質の変色は認められず、AgNC-処理象牙質はS.mutansによるコロニー形成に対する阻害効果を示した。これらの結果から、AgNCは抗菌的・審美的基質として、歯科療法で有望と考えられた。
  • Calcium phosphate coating on dental composite resins by a laser-assisted biomimetic process.
    A Joseph Nathanael; Ayako Oyane; Maki Nakamura; Kenji Koga; Erika Nishida; Saori Tanaka; Hirofumi Miyaji
    Heliyon, 4, 8, e00734, Aug. 2018, [Peer-reviewed], [International Magazine]
    English, Scientific journal, OBJECTIVES: Dental composite resins with better biocompatibility and osteoconductivity have been sought in endodontic treatments. This study aimed to develop a technique to produce the osteoconductive resin surfaces through calcium phosphate (CaP) coating using a laser-assisted biomimetic (LAB) process. METHODS: Light-cured, acrylic-based composite resins were used as substrates. The resin substrate was subjected to a LAB process comprising Nd:YAG pulsed laser irradiation in a supersaturated CaP solution. The LAB-processed substrate was immersed for 3 days in a simulated body fluid (SBF) for the preliminary osteoconductivity assessment. RESULTS: After irradiation for 30 min, the resin surfaces were partly coated with a newly formed CaP layer. The coating layer contained hydroxyapatite as the main crystalline phase and the coating coverage depended on the laser wavelength and the type of resin. The LAB-processed CaP-coated surface exhibited apatite-forming ability in SBF. CONCLUSIONS: LAB process is effective for CaP coating on light-cured dental composite resins and improving their osteoconductivity. CLINICAL SIGNIFICANCE: The LAB process is a potential new tool to create a cementum-like osteoconductive surface on dental composite resins.
  • Evaluation of Tissue Behavior on Three-dimensional Collagen Scaffold Coated with Carbon Nanotubes and β-tricalcium Phosphate Nanoparticles
    Hirofumi MIYAJI; Shusuke MURAKAMI; Erika NISHIDA; Tsukasa AKASAKA; Bunshi FUGETSU; Junko UMEDA; Katsuyoshi KONDOH; Tadashi IIZUKA; Tsutomu SUGAYA
    Journal of Oral Tissue Engineering, 15, 3, 123, 130, May 2018, [Peer-reviewed]
  • Near-infrared Irradiation and Graphene Oxide Film Fabricated on Dentin Surface Exhibit Photothermal and Antibacterial Effects
    Nagao Keishi; Miyaji Hirofumi; Nishida Erika; Akasaka Tsukasa; Miyata Saori; Shitomi Kanako; Mayumi Kayoko; Kato Akihito; Sugaya Tsutomu
    Journal of Oral Hygiene & Health, 6, 1, 231, 231, OMICS International, 10 Jan. 2018, [Peer-reviewed]
    English, Scientific journal
  • Bone induction by α-tricalcium phosphate microparticle emulsion containing simvastatin
    Akito Tateyama; Akihito Kato; Hirofumi Miyaji; Erika Nishida; Yasuhiko Iwasaki; Syuji Fujii; Kohei Kawamoto; Kanako Shitomi; Tomokazu Furihata; Kayoko Mayumi; Tsutomu Sugaya
    Nano Biomedicine, 9, 2, 69, 76, National Institute of Informatics, 2018, [Peer-reviewed]
    English, Scientific journal
  • Characterization and evaluation of graphene oxide scaffold for periodontal wound healing of class II furcation defects in dog.
    Kohei Kawamoto; Hirofumi Miyaji; Erika Nishida; Saori Miyata; Akihito Kato; Akito Tateyama; Tomokazu Furihata; Kanako Shitomi; Toshihiko Iwanaga; Tsutomu Sugaya
    International journal of nanomedicine, 13, 2365, 2376, 2018, [Peer-reviewed], [International Magazine]
    English, Scientific journal, INTRODUCTION: The 3-dimensional scaffold plays a key role in volume and quality of repair tissue in periodontal tissue engineering therapy. We fabricated a novel 3D collagen scaffold containing carbon-based 2-dimensional layered material, named graphene oxide (GO). The aim of this study was to characterize and assess GO scaffold for periodontal tissue healing of class II furcation defects in dog. MATERIALS AND METHODS: GO scaffolds were prepared by coating the surface of a 3D collagen sponge scaffold with GO dispersion. Scaffolds were characterized using cytotoxicity and tissue reactivity tests. In addition, GO scaffold was implanted into dog class II furcation defects and periodontal healing was investigated at 4 weeks postsurgery. RESULTS: GO scaffold exhibited low cytotoxicity and enhanced cellular ingrowth behavior and rat bone forming ability. In addition, GO scaffold stimulated healing of dog class II furcation defects. Periodontal attachment formation, including alveolar bone, periodontal ligament-like tissue, and cementum-like tissue, was significantly increased by GO scaffold implantation, compared with untreated scaffold. CONCLUSION: The results suggest that GO scaffold is biocompatible and possesses excellent bone and periodontal tissue formation ability. Therefore, GO scaffold would be beneficial for periodontal tissue engineering therapy.
  • Dose effects of beta-tricalcium phosphate nanoparticles on biocompatibility and bone conductive ability of three-dimensional collagen scaffolds.
    Shusuke Murakami; Hirofumi Miyaji; Erika Nishida; Kohei Kawamoto; Saori Miyata; Hiroko Takita; Tsukasa Akasaka; Bunshi Fugetsu; Toshihiko Iwanaga; Hiromi Hongo; Norio Amizuka; Tsutomu Sugaya; Masamitsu Kawanami
    Dental materials journal, 36, 5, 573, 583, 26 Sep. 2017, [Peer-reviewed], [Domestic magazines]
    English, Scientific journal, Three-dimensional collagen scaffolds coated with beta-tricalcium phosphate (β-TCP) nanoparticles reportedly exhibit good bioactivity and biodegradability. Dose effects of β-TCP nanoparticles on biocompatibility and bone forming ability were then examined. Collagen scaffold was applied with 1, 5, 10, and 25 wt% β-TCP nanoparticle dispersion and designated TCP1, TCP5, TCP10, and TCP25, respectively. Compressive strength, calcium ion release and enzyme resistance of scaffolds with β-TCP nanoparticles applied increased with β-TCP dose. TCP5 showed excellent cell-ingrowth behavior in rat subcutaneous tissue. When TCP10 was applied, osteoblastic cell proliferation and rat cranial bone augmentation were greater than for any other scaffold. The bone area of TCP10 was 7.7-fold greater than that of non-treated scaffold. In contrast, TCP25 consistently exhibited adverse biological effects. These results suggest that the application dose of β-TCP nanoparticles affects the scaffold bioproperties; consequently, the bone conductive ability of TCP10 was remarkable.
  • Antibacterial and cytotoxic effects of photoexcited Au clusters via blue high-power or white low-power light emitting diode irradiation
    Saori Miyata; Hirofumi Miyaji; Hideya Kawasaki; Erika Nishida; Kanako Shitomi; Tsukasa Akasaka; Saori Tanaka; Tadashi Iizuka; Tsutomu Sugaya
    Biology, Engineering and Medicine, 2, 4, 1, 4, Open Access Text, Sep. 2017, [Peer-reviewed]
    English, Scientific journal, The development of photosensitizers and light sources has enabled the use of antimicrobial photodynamic therapy (aPDT) in various dental therapies. In the presentstudy, we compared the antibacterial and cytotoxic effects of Au clusters photoexcited by blue and white LED irradiation. We fabricated novel photosensitizers,captopril-protected gold (Capt-Au) clusters and lysozyme-stabilized gold (Lyz-Au) clusters, for aPDT. Au clusters were then photoexcited by two kinds of lightsources, blue high-power and white low-power light-emitting diodes (LEDs). Since white LED contains a wide spectrum of light (400–750 nm), white LED wouldbe relevant for aPDT even if using a low-power source.The turbidity and viability of Streptococcus mutans were assessed following application of Capt-Au clusters (500 μg/mL) or Lyz-Au clusters (1,000 μg/mL) photoexcitedby a blue high-power LED (1,000 mW/cm2) or white low-power LED (80 mW/cm2). In addition, the cytotoxicity of Au clusters and LED irradiation was evaluatedin NIH3T3 and MC3T3-E1 cells.Au clusters photoexcited by the white low-power LED equally decreased the turbidity and viability of S. mutans compared with blue high-power LED. However,Au clusters photoexcited by white LED irradiation caused decreased cytotoxicity in mammalian cells compared with those photoexcited by blue LED irradiation. Inconclusion, white LEDs possess biosafe properties for aPDT using Au clusters.
  • In Vitro and in Vivo Analysis of Mineralized Collagen-Based Sponges Prepared by a Plasma- and Precursor-Assisted Biomimetic Process.
    A Joseph Nathanael; Ayako Oyane; Maki Nakamura; Ikuko Sakamaki; Erika Nishida; Yukimi Kanemoto; Hirofumi Miyaji
    ACS applied materials & interfaces, 9, 27, 22185, 22194, 12 Jul. 2017, [Peer-reviewed], [International Magazine]
    English, Scientific journal, Three-dimensional (3D) porous scaffolds for supporting cell adhesion and growth play a vital role in tissue engineering applications. In the present study, three different collagen-based 3D sponges were functionalized by apatite coating. The sponges were coated with apatite on their outer and inner surfaces while retaining their interconnecting pores. To achieve this, we employed a vacuum degassing system in our plasma- and precursor-assisted biomimetic process using a supersaturated calcium phosphate solution. The resulting apatite-coated sponges (mineralized sponges) showed better cell adhesion properties in vitro for osteoblast-like MC3T3-E1 cells compared to that of uncoated sponges. The three mineralized sponges were implanted in the subcutaneous tissue of rats. Upon histological evaluation after 10 days, the mineralized sponges showed cell in-growth rates that were approximately 4-fold greater than those of the untreated sponges without any notable inflammatory reactions. As these sponges are composed of clinically approved collagen-based frameworks and possess a 3D porous structure with a mineralized surface appropriate for cell adhesion and internalization, further in vitro and in vivo studies should be conducted regarding tissue engineering applications.
  • Antimicrobial photodynamic activity and cytocompatibility of Au25(Capt)18 clusters photoexcited by blue LED light irradiation.
    Saori Miyata; Hirofumi Miyaji; Hideya Kawasaki; Masaki Yamamoto; Erika Nishida; Hiroko Takita; Tsukasa Akasaka; Natsumi Ushijima; Toshihiko Iwanaga; Tsutomu Sugaya
    International journal of nanomedicine, 12, 2703, 2716, 2017, [Peer-reviewed], [International Magazine]
    English, Scientific journal, Antimicrobial photodynamic therapy (aPDT) has beneficial effects in dental treatment. We applied captopril-protected gold (Au25(Capt)18) clusters as a novel photosensitizer for aPDT. Photoexcited Au clusters under light irradiation generated singlet oxygen (1O2). Accordingly, the antimicrobial and cytotoxic effects of Au25(Capt)18 clusters under dental blue light-emitting diode (LED) irradiation were evaluated. 1O2 generation of Au25(Capt)18 clusters under blue LED irradiation (420-460 nm) was detected by a methotrexate (MTX) probe. The antimicrobial effects of photoexcited Au clusters (0, 5, 50, and 500 μg/mL) on oral bacterial cells, such as Streptococcus mutans, Aggregatibacter actinomycetemcomitans, and Porphyromonas gingivalis, were assessed by morphological observations and bacterial growth experiments. Cytotoxicity testing of Au clusters and blue LED irradiation was then performed against NIH3T3 and MC3T3-E1 cells. In addition, the biological performance of Au clusters (500 μg/mL) was compared to an organic dye photosensitizer, methylene blue (MB; 10 and 100 μg/mL). We confirmed the 1O2 generation ability of Au25(Capt)18 clusters through the fluorescence spectra of oxidized MTX. Successful application of photoexcited Au clusters to aPDT was demonstrated by dose-dependent decreases in the turbidity of oral bacterial cells. Morphological observation revealed that application of Au clusters stimulated destruction of bacterial cell walls and inhibited biofilm formation. Aggregation of Au clusters around bacterial cells was fluorescently observed. However, photoexcited Au clusters did not negatively affect the adhesion, spreading, and proliferation of mammalian cells, particularly at lower doses. In addition, application of Au clusters demonstrated significantly better cytocompatibility compared to MB. We found that a combination of Au25(Capt)18 clusters and blue LED irradiation exhibited good antimicrobial effects through 1O2 generation and biosafe characteristics, which is desirable for aPDT in dentistry.
  • Periodontal tissue engineering by nano beta-tricalcium phosphate scaffold and fibroblast growth factor-2 in one-wall infrabony defects of dogs
    K. Ogawa; H. Miyaji; A. Kato; Y. Kosen; T. Momose; T. Yoshida; E. Nishida; S. Miyata; S. Murakami; H. Takita; B. Fugetsu; T. Sugaya; M. Kawanami
    JOURNAL OF PERIODONTAL RESEARCH, 51, 6, 758, 767, Dec. 2016, [Peer-reviewed]
    English, Scientific journal
  • カーボンナノシート新素材『酸化グラフェン』の歯周病治療への展開
    Hirofumi Miyaji; Erika Nishida
    Nihon Shishubyo Gakkai Kaishi (Journal of the Japanese Society of Periodontology), 58, 2, 65, 71, Japanese Society of Periodontology, Jul. 2016, [Peer-reviewed]
    Japanese, 歯周病治療において、新しい骨補填材やティッシュエンジニアリング法が開発され、多面的に新技術が応用されつつある。グラファイトから生成されるカーボンナノシート「酸化グラフェン」は、安全性が高く優れた理工学的特性を有するとともに、抗菌性やドラッグデリバリー効果、培養細胞へのポジティブな効果が報告されている。酸化グラフェンについて説明し、酸化グラフェンの細胞活性への効果、酸化グラフェンのティッシュエンジニアリングへの応用、酸化グラフェンの抗菌性評価について述べた。
  • Modification of Composite Resin Surface with Carbon Nanotubes Enhances Cell Proliferation
    Saori TANAKA; Hirofumi MIYAJI; Erika NISHIDA; Kana INOUE; Saori MIYATA; Akihito KATO; Izumi KANAYAMA; Shusuke MURAKAMI; Kohei KAWAMOTO; Bunshi FUGETSU; Toru TANAKA; Hiroko TAKITA; Tadashi IIZUKA; Masamitsu KAWANAMI
    Nano Biomedicine, 8, 1, 27, 34, Jun. 2016, [Peer-reviewed]
    English, Scientific journal
  • Preparation of Chitosan-Gelatin Based Sponge Cross-Linked with GlcNAc for Bone Tissue Engineering
    Thitirat Chaochai; Hirofumi Miyaji; Takashi Yoshida; Erika Nishida; Tetsuya Furuike; Hiroshi Tamura
    Journal of Chitin and Chitosan Science, 4, 1, 1, 8, American Scientific Publishers, 01 Mar. 2016, [Peer-reviewed]
    Scientific journal
  • Bone-forming Effects of Collagen Scaffold Containing β-tricalcium Phosphate Nanoparticles on Extraction Sockets in Dogs
    Akihito KATO; Masamitsu KAWANAMI; Hirofumi MIYAJI; Kosuke OGAWA; Takehito MOMOSE; Erika NISHIDA; Syusuke MURAKAMI; Takashi YOSHIDA; Saori TANAKA; Tsutomu SUGAYA
    The Japanese Journal of Conservative Dentistry, 59, 4, 351, 358, The Japanese Society of Conservative Dentistry, 2016, [Peer-reviewed]
    Japanese,

     Purpose: Beta-tricalcium phosphate (β-TCP) exhibits biocompatibility and osteoconductivity and has been used clinically as a bone graft material. However, conventional β-TCP degrades slowly, with residual material frequently inducing aberrant healing. We therefore developed a collagen scaffold containing β-TCP nanoparticles by applying nanoscale dispersing technology. When the nano-β-TCP/collagen scaffold was implanted into rat cranial bone, its degradation and bone augmentation were remarkable when compared with collagen sponge. Accordingly, we evaluated the bone-forming effects of nano-β-TCP/collagen scaffold on extraction sockets in dogs.

     Methods: β-TCP powder (average particle size: 2.3 μm) was pulverized into nanoscale particles and dispersed into distilled water along with the surfactant sodium cholate (0.2 wt%). Collagen sponge was immersed in a dispersion (1 wt%) of β-TCP nanoparticles. This was followed by rinsing and freeze-drying to yield the nano-β-TCP/collagen scaffold. The surface of the scaffold was characterized by SEM. Subsequently, the extraction socket of a maxillary first premolar was filled with nano-β-TCP/collagen scaffold in the experimental group, while collagen sponge was applied to the socket in the control group. Radiographic images of the socket were then obtained at baseline, and at 1, 3 and 5 weeks after surgery. Histological observations were performed at 2 and 5 weeks.

     Results: SEM images showed nanosized (approx. 100 nm) β-TCP particles attached to the fibers of collagen sponge. The interconnected spaces within the collagen sponge were not filled with β-TCP particles. In the experimental group, the extraction socket showed increased radiopacity when compared with the control group. Histological observation at 2 weeks revealed that new bone was present in the socket in the experimental group. In addition, ingrowth of cells and blood vessels was detected in the nano-β-TCP/collagen scaffold. In contrast, only slight new bone growth was seen in the control group. At 5 weeks in the experimental group, the scaffold had disappeared and the extraction socket was fully filled with new bone. In the control group, although new bone was detected, connective tissue and residual collagen sponge were also observed in part of the extraction socket. Newly formed bone area in the experimental group (25.1%) was significantly greater when compared with the control group (7.6%). Residual material area in the experimental group (59.1%) was significantly less when compared with the control group (81.2%).

     Conclusion: Nano-β-TCP/collagen scaffold exhibited high biocompatibility and degradability. New bone formation in tooth extraction sockets of dogs was facilitated by implantation of nano-β-TCP/collagen scaffold.

  • Graphene oxide scaffold accelerates cellular proliferative response and alveolar bone healing of tooth extraction socket.
    Erika Nishida; Hirofumi Miyaji; Akihito Kato; Hiroko Takita; Toshihiko Iwanaga; Takehito Momose; Kosuke Ogawa; Shusuke Murakami; Tsutomu Sugaya; Masamitsu Kawanami
    International journal of nanomedicine, 11, 2265, 77, 2016, [Peer-reviewed], [International Magazine]
    English, Scientific journal, Graphene oxide (GO) consisting of a carbon monolayer has been widely investigated for tissue engineering platforms because of its unique properties. For this study, we fabricated a GO-applied scaffold and assessed the cellular and tissue behaviors in the scaffold. A preclinical test was conducted to ascertain whether the GO scaffold promoted bone induction in dog tooth extraction sockets. For this study, GO scaffolds were prepared by coating the surface of a collagen sponge scaffold with 0.1 and 1 µg/mL GO dispersion. Scaffolds were characterized using scanning electron microscopy (SEM), physical testing, cell seeding, and rat subcutaneous implant testing. Then a GO scaffold was implanted into a dog tooth extraction socket. Histological observations were made at 2 weeks postsurgery. SEM observations show that GO attached to the surface of collagen scaffold struts. The GO scaffold exhibited an interconnected structure resembling that of control subjects. GO application improved the physical strength, enzyme resistance, and adsorption of calcium and proteins. Cytocompatibility tests showed that GO application significantly increased osteoblastic MC3T3-E1 cell proliferation. In addition, an assessment of rat subcutaneous tissue response revealed that implantation of 1 µg/mL GO scaffold stimulated cellular ingrowth behavior, suggesting that the GO scaffold exhibited good biocompatibility. The tissue ingrowth area and DNA contents of 1 µg/mL GO scaffold were, respectively, approximately 2.5-fold and 1.4-fold greater than those of the control. Particularly, the infiltration of ED2-positive (M2) macrophages and blood vessels were prominent in the GO scaffold. Dog bone-formation tests showed that 1 µg/mL GO scaffold implantation enhanced bone formation. New bone formation following GO scaffold implantation was enhanced fivefold compared to that in control subjects. These results suggest that GO was biocompatible and had high bone-formation capability for the scaffold. The GO scaffold is expected to be beneficial for bone tissue engineering therapy.
  • Collagen Hydrogel Scaffold and Fibroblast Growth Factor-2 Accelerate Periodontal Healing of Class II Furcation Defects in Dog.
    Takehito Momose; Hirofumi Miyaji; Akihito Kato; Kosuke Ogawa; Takashi Yoshida; Erika Nishida; Syusuke Murakami; Yuta Kosen; Tsutomu Sugaya; Masamitsu Kawanami
    The open dentistry journal, 10, 347, 59, 2016, [Peer-reviewed], [International Magazine]
    English, Scientific journal, OBJECTIVE: Collagen hydrogel scaffold exhibits bio-safe properties and facilitates periodontal wound healing. However, regenerated tissue volume is insufficient. Fibroblast growth factor-2 (FGF2) up-regulates cell behaviors and subsequent wound healing. We evaluated whether periodontal wound healing is promoted by application of collagen hydrogel scaffold in combination with FGF2 in furcation defects in beagle dogs. METHODS: Collagen hydrogel was fabricated from bovine type I collagen with an ascorbate-copper ion cross-linking system. Collagen hydrogel was mingled with FGF2 and injected into sponge-form collagen. Subsequently, FGF2 (50 µg)/collagen hydrogel scaffold and collagen hydrogel scaffold alone were implanted into class II furcation defects in dogs. In addition, no implantation was performed as a control. Histometric parameters were assessed at 10 days and 4 weeks after surgery. RESULT: FGF2 application to scaffold promoted considerable cell and tissue ingrowth containing numerous cells and blood vessel-like structure at day 10. At 4 weeks, reconstruction of alveolar bone was stimulated by implantation of scaffold loaded with FGF2. Furthermore, periodontal attachment, consisting of cementum-like tissue, periodontal ligament-like tissue and Sharpey's fibers, was also repaired, indicating that FGF2-loaded scaffold guided self-assembly and then re-established the function of periodontal organs. Aberrant healing, such as ankylosis and root resorption, was not observed. CONCLUSION: FGF2-loaded collagen hydrogel scaffold possessed excellent biocompatibility and strongly promoted periodontal tissue engineering, including periodontal attachment re-organization.
  • Friction behavior of network-structured CNT coating on pure titanium plate
    Junko Umeda; Bunshi Fugetsu; Erika Nishida; Hirofumi Miyaji; Katsuyoshi Kondoh
    APPLIED SURFACE SCIENCE, 357, 721, 727, Dec. 2015, [Peer-reviewed]
    English, Scientific journal
  • Biological Response to Nanostructure of Carbon Nanotube/titanium Composite Surfaces
    Erika NISHIDA; Hirofumi MIYAJI; Junko UMEDA; Katsuyoshi KONDOH; Hiroko TAKITA; Izumi KANAYAMA; Saori TANAKA; Akihito KATO; Bunshi FUGETSU; Tsukasa AKASAKA; Masamitsu KAWANAMI
    Nano Biomedicine, 7, 1, 11, 20, Jun. 2015, [Peer-reviewed]
    English, Scientific journal
  • Bone augmentation using a highly porous PLGA/beta-TCP scaffold containing fibroblast growth factor-2
    T. Yoshida; H. Miyaji; K. Otani; K. Inoue; K. Nakane; H. Nishimura; A. Ibara; A. Shimada; K. Ogawa; E. Nishida; T. Sugaya; L. Sun; B. Fugetsu; M. Kawanami
    JOURNAL OF PERIODONTAL RESEARCH, 50, 2, 265, 273, Apr. 2015, [Peer-reviewed]
    English, Scientific journal
  • Graphene oxide coating facilitates the bioactivity of scaffold material for tissue engineering
    Erika Nishida; Hirofumi Miyaji; Hiroko Takita; Izumi Kanayama; Maiko Tsuji; Tsukasa Akasaka; Tsutomu Sugaya; Ryuji Sakagami; Masamitsu Kawanami
    JAPANESE JOURNAL OF APPLIED PHYSICS, 53, 6, 06JD04, Jun. 2014, [Peer-reviewed]
    English, Scientific journal
  • Comparative study of bioactivity of collagen scaffolds coated with graphene oxide and reduced graphene oxide
    Izumi Kanayama; Hirofumi Miyaji; Hiroko Takita; Erika Nishida; Maiko Tsuji; Bunshi Fugetsu; Ling Sun; Kana Inoue; A. Sako Ibara; Tsukasa Akasaka; Tsutomu Sugaya; Masamitsu Kawanami
    INTERNATIONAL JOURNAL OF NANOMEDICINE, 9, 3363, 3373, 2014, [Peer-reviewed]
    English, Scientific journal
  • Bone Augmentation in Rat by Highly Porous β-TCP Scaffolds with Different Open-cell Sizes in Combination with Fibroblast Growth Factor-2
    MIYAJI Hirofumi; YOKOYAMA Hiroyuki; KOSEN Yuta; NISHIMURA Hiroyuki; NAKANE Kazuyasu; TANAKA Saori; OTANI Kaori; INOUE Kana; IBARA Asako; KANAYAMA Izumi; YOSHIDA Takashi; OGAWA Kosuke; NISHIDA Erika; KAWANAMI Masamitsu
    J. Oral Tissue Engin., 10, 3, 172, 181, Japanese Association of Regenerative Dentistry, 2013, [Peer-reviewed]
    English, We prepared highly porous beta-tricalcium phosphate (β-TCP) scaffolds with different open-cell structure sizes. The aim of this study was to examine whether the open-cell size of the scaffold affected osteoinduction in combination with fibroblast growth factor-2 (FGF2) in rats. Polyurethane foam was immersed in β-TCP slurry and sintered in a furnace. Porous β-TCP scaffolds were prepared in three cell sizes (0.6, 0.4 and 0.3 mm) and characterized. Subsequently, each scaffold with FGF2 was implanted to rat cranial bone. Histomorphometric analyses were taken at 35 days post-surgery. The results showed that each β-TCP scaffold exhibited fully interconnected porosity, and frequently allowed bone tissue ingrowth. The 0.4-mm cell sized scaffold significantly promoted bone augmentation compared to the 0.3-mm type. Resorption of the β-TCP scaffold of 0.4-mm cell size was frequently accelerated. In conclusion, FGF2-loaded β-TCP scaffolds with 0.4-mm cell size would be effective for bone tissue engineering.
  • Osteoconductivity and Biodegradability of Collagen Scaffold Coated with Nano-beta-TCP and Fibroblast Growth Factor 2
    Asako Ibara; Hirofumi Miyaji; Bunshi Fugetsu; Erika Nishida; Hiroko Takita; Saori Tanaka; Tsutomu Sugaya; Masamitsu Kawanami
    JOURNAL OF NANOMATERIALS, 2013, [Peer-reviewed]
    English, Scientific journal
■ Other Activities and Achievements
■ Syllabus
  • フロンティア基礎科目, 2024年, 学士課程, 歯学部
■ Research Themes
  • 人工エナメルその場合成による異種接合界面の精密制御と医用展開
    科学研究費助成事業
    26 Jun. 2026 - 31 Mar. 2029
    大矢根 綾子; 中村 真紀; 秋山 陽久; 島本 一正; 宮治 裕史; 西田 絵利香
    日本学術振興会, 挑戦的研究(開拓), 国立研究開発法人産業技術総合研究所, 26K21970
  • レーザーで軟化象牙質をアパタイトに置換する－根面う蝕治療法の新規開発
    科学研究費助成事業
    01 Apr. 2025 - 31 Mar. 2028
    宮治 裕史; 大矢根 綾子; 松田 康裕; 西田 絵利香; 蔀 佳奈子
    日本学術振興会, 基盤研究(B), 北海道大学, 25K02808
  • LABプロセスを用いたインプラント周囲炎の革新的再生治療法創出
    科学研究費助成事業
    01 Apr. 2025 - 31 Mar. 2028
    西田 絵利香; 宮治 裕史; 蔀 佳奈子; 黒嶋 伸一郎; 大矢根 綾子; 島袋 将弥
    日本学術振興会, 基盤研究(C), 北海道大学, 25K13061
  • インプラント周囲炎治療のための抗菌・骨形成促進ナノ粒子の術中3次元デリバリー
    科学研究費助成事業
    01 Apr. 2024 - 31 Mar. 2028
    中村 真紀; 奈良崎 愛子; 宮治 裕史; 西田 絵利香
    日本学術振興会, 基盤研究(B), 国立研究開発法人産業技術総合研究所, 24K03292
  • レーザーによる抗菌加工面が健康長寿に貢献！新たな口腔カンジダ症治療への展開
    科学研究費助成事業
    Apr. 2025 - Mar. 2028
    田中 佐織; 宮治裕史; 大矢根綾子; 西田絵利香
    日本学術振興会, 基盤研究(C), 北海道大学, 25K12999
  • インプラント周囲炎治療のための抗菌・骨形成促進ナノ粒子の術中3次元デリバリー
    科学研究費助成事業
    Apr. 2024 - Mar. 2028
    中村 真紀; 奈良崎 愛子; 宮治 裕史; 西田 絵利香
    日本学術振興会, 基盤研究(B), 国立研究開発法人産業技術総合研究所, 24K03292
  • 人工バイオミネラリゼーションの光制御と歯面機能デザイン
    科学研究費助成事業
    01 Apr. 2024 - 31 Mar. 2027
    大矢根 綾子; 宮治 裕史; 西田 絵利香
    日本学術振興会, 基盤研究(B), 国立研究開発法人産業技術総合研究所, 24K03294
  • ２段階薬剤放出性第４世代スキャフォールドの歯周組織再生への応用
    科学研究費助成事業
    Apr. 2022 - Mar. 2025
    西田 絵利香; 宮治 裕史; 大矢根 綾子; 中村 真紀; 赤坂 司
    アパタイト2層構造化による２段階薬剤放出性第４世代スキャフォールド構築のため，初年度はまず1層目の構築・評価を行った．
    1層目として，アパタイトの難溶化（溶解性低下）と抗菌性の期待される生体微量元素（フッ素）を種々の濃度（0～1000 uM）でCaP過飽和溶液に添加し，スキャフォールド上にフッ素含有アパタイト層を作製した．
    その結果，スキャフォールド内部および外部表面への均一なフッ素含有アパタイト層の生成を確認し，過飽和溶液へのフッ素添加濃度の増加により生成するアパタイト層のフッ素置換率（F/P比で評価）向上が認められた．
    成膜後のスキャフォールドを生食に浸漬して溶解性等を評価したところ，過飽和溶液へのフッ素添加濃度の増加に伴い，生食中へのアパタイトの溶解量（7日後）は減少した．アパタイト結晶にフッ化物イオンが取り込まれることにより，層の難溶化したと考えられる，また，生食中へのフッ素溶出量も増加した．
    以上より，フッ化物イオンをバイオミメティックコーティング法によりアパタイト層に取り込むことに成功した．フッ化物濃度の増加とともにアパタイト層の溶解度が低下し，減少した．
    日本学術振興会, 基盤研究(C), 北海道大学, 22K10012
  • 高周波電流によるファイル未到達根管における歯髄の蒸散と根管の殺菌
    科学研究費助成事業
    Apr. 2021 - Mar. 2024
    菅谷 勉; 西田 絵利香
    牛象牙質にΦ0.1㎜、0.4mmの模擬根管を１つまたは２つ作製し、電圧225Vで通電を行って、各根管壁の焼灼状態をSEMおよびEDSで評価した。その結果、通電時間を長くすると根管壁からCやOの検出が低下し、さらに通電時間をながくするとCaとPのみが検出されるようになって、SEMでは溶岩状に象牙質が溶融凝固した部位が増加した。この焼灼効果はΦ0.1㎜よりΦ0.4mmの方が高く、4秒の通電で根管壁はほぼ全面が溶融凝固した像を示した。Φ0.1mmと0.4mmの2根管モデルでは、それぞれ単根管モデルとほぼ同様の変化を示し、通電時間が2秒ではΦ0.1mmの根管壁に有機質が多量に残存したが、４秒に延長すると80％が蒸散可能であった。さらに、根管壁に炭化物の残存はなく、蒸散と洗浄が同時に行われている可能性が示された。
    一方、イヌの健全歯を髄腔開拡し、高周波電流を通電して歯髄の焼灼状態を病理組織学的に検討した。その結果、ファイルが根尖孔から1-2mm歯冠側で150または225Vを1秒印加することで、主根管および根尖分枝内の歯髄は壊死し、とくに血管は構造を失って研究や血漿の変性が認められた。根尖から4mm歯冠側の位置で225Vを1秒通電しても、概ね同様の結果であったが、根尖分枝内ではわずかに残髄する可能性が見られた。また、歯根膜には225Vを印加した場合にはわずかに蒸散がみられたが、その範囲は10μm程度であり、その周囲に熱変性は見られなかった。しかし、歯根膜にファイルが接した状態で通電すると、歯槽骨吸収も観察された。さらに根尖を穿通してグライドパス後に通電を行うと、歯根膜への機械的損傷による炎症が生じるとともに、根尖分枝内の焼灼がやや不十分になった。
    日本学術振興会, 基盤研究(C), 北海道大学, 21K09908
  • Biomimetic apatite coating on root surface for prevention of root caries
    Grants-in-Aid for Scientific Research
    01 Apr. 2019 - 31 Mar. 2023
    TANAKA SAORI
    The aim of this study was to develop a new method of root surface caries prevention and control by coating antimicrobial apatite on exposed root cementum using a laser-assisted biomimetic technique.
    1.The surface analysis of the laser irradiated cementitious substrate in supersaturated CaP solution with NaF showed that F was detected on the irradiated surface, and the formation of fluorine-containing apatite was confirmed from the increase in the Ca/C element ratio. 2. Cementitious materials in supersaturated solution of CaP with NaF were irradiated with a semiconductor laser. FAp was deposited on the irradiated surface, and a significant increase in Knoop hardness was observed compared to the unirradiated surface. 3. Demineralization inhibiting effect was confirmed. 4. The possibility of intraoral application was found from experiments using beagle dogs.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 19K10103
  • Biomimetic apatite coating on root surface for prevention of root caries
    Grants-in-Aid for Scientific Research
    Apr. 2019 - Mar. 2023
    田中 佐織; 大矢根 綾子; 宮治 裕史; 西田 絵利香; 田中 享
    本研究は，レーザー援用バイオミメティック法により，露出歯根セメント質上にアパタイトをコーティングして，新しい根面う蝕予防法及び進行抑制法を開発，実現することを目的として行われる.(1)セメント質面にアパタイトを析出させることができるか(2)生理活性物質を添加し，セメント質の無機質（アパタイト）及び有機質（コラーゲン）を保護し耐酸性を向上させることができるかを明らかにすることである．
    R1年度はNaFを添加したCaP過飽和溶液中にセメント質基材（直径約5 mm）にNd:YAGナノ秒パルスレーザーの非集光ビーム（355 nm, 6 W/cm2）を10分間照射後，照射面および非照射面を，走査電子顕微鏡（SEM）とエネルギー分散型X線分析装置（EDX）で分析した．EDX分析の結果，照射面にはCaとPに加え新たにFが検出され，Ca/C元素比の上昇が認められた．これらの結果は，照射面にフッ素含有アパタイト（FAp）が生成したことを示した．
    R2～3年度は飽和液中レーザー照射法により、セメント質基材を作製した。基材の表面に、光吸収剤を塗布し、乾燥させた。フッ化ナトリウム（1 mM）を添加したリン酸カルシウム過飽和溶液中に基材を設置し、その表面にレーザー光（昭和薬品化工株式会社製Sレーザー、波長：808 nm）を3分間照射した。照射距離は10 mm、出力は3 Wとした．超純水にて洗浄，風乾し，未照射および照射後の表面のヌープ硬度(KHN)を測定した.照射後のセメント質表面にFApが成膜されたことで，未照射セメント質表面と比較して，KHNの有意な増加が認められた．わずか3分の過飽和液中レーザー照射によってFApを成膜できることを確認した．耐酸性をKHNで測定した結果，測定値にばらつきがみられたため，追加実験の実施のために歯基材を調整している．
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 19K10103
  • Safe and reliable periodontal tissue regeneration using human collagen with nanoceramix.
    Grants-in-Aid for Scientific Research
    Apr. 2018 - Mar. 2022
    Nishida Erika
    Human type I collagen-like recombinant peptides have attracted attention as biomaterials that do not contain animal-derived components. The β-TCP/RCP, which was made by granulating RCP and blending it with β-tricalcium phosphate (β-TCP) particles, showed good biocompatibility and osteogenic potential by in vitro evaluation and evaluation in a rat skull defect model. Next, we examined whether there was a periodontal tissue regenerative effect in beagle dogs. Eight weeks after surgery, the experimental group had 2.2 times more new bone than the control group. In addition, 2.1 times more periodontal ligament-like tissue was formed, and gingival recession was significantly suppressed. These results suggest that β-TCP/RCP is effective as a periodontal tissue regeneration material.
    Japan Society for the Promotion of Science, Grant-in-Aid for Early-Career Scientists, Hokkaido University, 18K17038
  • Fabrication and application of nanomaterial using biomineralization method for periodontal tissue engineering
    Grants-in-Aid for Scientific Research
    Apr. 2016 - Mar. 2019
    Miyaji Hirofumi; OYANE Ayako
    We fabricated the nano-structured apatite scaffold using biomineralization method to imitate the bone formation in the body. The evaluation of biocompatibility, bone inductive effect and periodontal regenerative activity of apatite scaffold were carried out. In addition, we obtained the apatite scaffold loaded with fibroblast growth factor-2 (FGF2) to enhance the bio-properties of scaffold and assessed the bone forming ability.
    The results showed that apatite scaffold exhibited high biocompatibility and bone forming effect in rat cranial bone defect. Apatite scaffold stimulated the periodontal regeneration in class II furcation defect in beagle dogs. In addition, FGF-2 loaded apatite scaffold remarkably promoted the bone augmentation of rat skull bone, compared to pristine apatite scaffold. The nano-structured apatite scaffold would be beneficial for medical application in bone and periodontal tissue engineering.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 16K11822
  • Create periodontal tissue formation on composite resin! for improvement of reliability of bonding treatment
    Grants-in-Aid for Scientific Research
    Apr. 2016 - Mar. 2019
    TANAKA SAORI; OYANE AYAKO; NAKAMURA MAKI; Nathanael AJ; KATO AKIHITO; MIYATA SAORI; MAYUMI KAYOKO
    Composite resin (CR) is applied as a bonding treatment and as a root perforation. However, CR surface rarely reconstructs periodontal attachment apparatus.
    The laser-assisted biomimetic (LAB) process.This may improve the biocompatibility of CR through the surface modification. This study aimed to develop a technique to produce the osteoconductive resin surfaces through calcium phosphate (CaP) coating using LAB process.
    The LAB-processed substrate was immersed for 3 days in a simulated body fluid (SBF) for the preliminary osteoconductivity assessment.According to the results of the microscopic observation and the EDX analysis, nano- and micro-structured CaP layers were formed on the CR surfaces, after the LAB process. Thus,this study might suggest a possibility of the periodontal tissue formation on CR.The LAB process is a potential new tool to create a cementum-like osteoconductive surface on dental composite resins.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 16K11538
  • Evaluationt of regeneration of periodontal tissue of antibacterial scaffold using Ag/nanocarbon and
    Grants-in-Aid for Scientific Research
    Aug. 2016 - Mar. 2018
    Nishida Erika
    In this study, we aimed to demonstrate the periodontal regeneration effect by creating Ag supported nanocarbon scaffold. No cytotoxicity was observed in GO and Ag/GO scaffolds, and bacterial growth inhibitory effect was observed in Ag/GO scaffold in bacterial culture test. In the histological observation in rats, the biocompatibility of GO and Ag/GO scaffolds was better than that of collagen scaffolds. In dog extraction tooth extraction, there was no significant difference in bone regeneration at GO, Ag/GO scaffold.
    From the above, it was suggested that the GO coating improves the properties of the scaffold and that the Ag/GO scaffold could exhibit antibacterial properties.
    Japan Society for the Promotion of Science, Grant-in-Aid for Research Activity Start-up, Hokkaido University, 16H06604
  • Application of emulsion bone paste forming porous structure to periodontal treatment
    Grants-in-Aid for Scientific Research
    Apr. 2014 - Mar. 2017
    KATO Akihito; NISHIDA Erika; TATEYAMA Akito
    We developed bone paste using particle emulsion of α-Tricalcium phosphate (α-TCP) and Poly(lactic-co-glycolic) acid (PLGA), and evaluated the ability as bone regeneration material in vivo and in vitro. As a result, emulsion bone paste showed good biocompatibility in vivo, and more cell invasion into the material was observed by PLGA addition. If this new bone paste can be applied to periodontal disease, it is expected that a large amount of cells in the surrounding will invade the material, and it will be possible to obtain the effect of regeneration over conventional bone graft material.
    Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Hokkaido University, 26870016
  • Novel periodontal therapy using nanocarbon coating procedure
    Grants-in-Aid for Scientific Research
    Apr. 2013 - Mar. 2016
    Miyaji Hirofumi; TANAKA SAORI; KATO AKIHITO; FUGETSU BUNSHI; NISHIDA ERIKA
    Biocompatibility tests were performed to evaluate the biological properties of nanocarbon materials, such as graphene oxide (GO) and carbon nanotube (CNT). In addition, tooth coating procedure using GO and regenerative scaffold including GO were developed for application to periodontal therapy. Low dose of GO and CNT consistently exhibited good biocompatibility, in particular, CNT stimulated cell proliferative activity. The tooth coating procedure using GO solution provided the antimicrobial effect to the tooth surface. GO scaffold exhibited cytocompatibility and promoted tissue healing and bone formation when implanted in tooth extraction socket or furcation periodontal defect in dog. Consequently, nanocarbon materials would be available for medical application in periodontal therapy.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 25463210
  • A development of the bonding treatment of vertically fractured roots with periodontal regeneration on adhesive resin using nanotechnology
    Grants-in-Aid for Scientific Research
    Apr. 2013 - Mar. 2016
    TANAKA SAORI; MIYAJI HIROFUMI; INOUE KANA; TANAKA TORU; TANINO MISHIE; KATO AKIHITO; KANAYAMA IZUMI; NISHIDA ERIKA; MURAKMI SHUSUKE; KAWAMOTO KOHEI; MIYATA SAORI
    Composite resin (CR) is used the bonding treatment of vertically fractured roots and as a retrograde material following apiccectomy. We aimed to the periodontal regeneration on CR. Effective biological modification of the CR surface is thus needed to improve its biocompatibility. Carbon nanotubes (CNT) and β-TCP have useful properties such as promoting cell adhesion and proliferation. CR discs were coated by immersion in a dispersion of CNT and β-TCP. In the cell culture assay, the CNT-CR samples exhibited abundant cells and marked adhesion of filopodia to CNT. Cell proliferation assay indicated that the CNT-CR was significantly higher than the CR . This results showed that coating the surface of CR with CNT improved their biocompatibility. In vivo studies, we observed the bone-like hard tissue formation on a CNT-CR wrapped in cultured bone marrow stromal cell sheets. Thus, this experiment might suggest a possibility of the periodontal regeneration on CR.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 25462943
■ Industrial Property Rights
  • 亜鉛含有抗菌剤
    Patent right, 宮治 裕史; 西田 絵利香; 蔀 佳奈子; 浜本 朝子; 小野 博信; 郷田 隼, 国立大学法人北海道大学, 株式会社日本触媒
    特願2018-207370, 02 Nov. 2018
    特開2020-070277, 07 May 2020
    特許第7190132号
    202203006817539960
  • 抗菌剤組成物
    Patent right, 宮治 裕史; 西田 絵利香; 蔀 佳奈子; 小野 博信; 郷田 隼, 国立大学法人北海道大学, 株式会社日本触媒
    特願2018-207371, 02 Nov. 2018
    特開2020-070278, 07 May 2020
    特許第7177436号
    202203006940233921
  • コラーゲン様ペプチド及びリン酸カルシウムの複合体並びにこれを含む生体組織修復材
    Patent right, 宮治 裕史; 西田 絵利香; 宮田 さほり; 降籏 友和, 国立大学法人北海道大学
    特願2018-217792, 20 Nov. 2018
    特開2020-083796, 04 Jun. 2020
    202003004214421614
  • 亜鉛含有抗菌剤
    Patent right, 宮治 裕史; 西田 絵利香; 蔀 佳奈子; 浜本 朝子; 小野 博信; 郷田 隼, 国立大学法人北海道大学, 株式会社日本触媒
    特願2018-207370, 02 Nov. 2018
    特開2020-070277, 07 May 2020
    202003009450207978
  • 抗菌剤組成物
    Patent right, 宮治 裕史; 西田 絵利香; 蔀 佳奈子; 小野 博信; 郷田 隼, 国立大学法人北海道大学, 株式会社日本触媒
    特願2018-207371, 02 Nov. 2018
    特開2020-070278, 07 May 2020
    202003009691473466
  • 酸化グラフェンを用いた骨再生用又は皮膚再生用スキャフォールド
    Patent right, 宮治 裕史; 西田 絵利香; 川浪 雅光; 新開 妹井子; 三村 邦年, 国立大学法人北海道大学, 三菱瓦斯化学株式会社
    特願2015-037521, 27 Feb. 2015
    特開2016-158680, 05 Sep. 2016
    201603017565151755