倉科　佑太KURASHINA Yutaクラシナ　ユウタ

業績情報

氏名・連絡先

• 氏名

  クラシナ　ユウタ, 倉科　佑太, KURASHINA Yuta

主たる所属・職名

• 工学研究院　機械システム工学部門, 准教授

その他の所属

• 工学部　機械システム工学科

科学研究費助成事業

• 基盤研究（A）
  超高速マイクロ液滴衝突現象解明が拓く液滴衝突の新学理とその展開
  自 2024年, 至 2024年
• 基盤研究（B）
  分散データリザレクション：柔軟性と効率性を兼ね備えた計測情報再構成技術の創出
  自 2024年, 至 2024年
• 基盤研究（A）
  三次元組織の高度成熟化を自律的に達成する知能化培養システム基盤の創出
  自 2024年, 至 2024年
• 基盤研究(B)
  超音波遠心駆動システムによる微小・高粘性のマイクロゲル粒子生成法の構築
  自 2024年, 至 2027年
• 挑戦的研究（萌芽）
  表面弾性波デバイスを用いた細胞の超音波応答性イオンチャネルの可視化
  自 2024年, 至 2025年
• 基盤研究（A）
  三次元組織の高度成熟化を自律的に達成する知能化培養システム基盤の創出
  自 2023年, 至 2023年
• 挑戦的研究（萌芽）
  超音波を用いたポリフェノール配合マイクロニードル薬剤投与の高速化
  自 2022年, 至 2023年
• 国際共同研究加速基金（国際共同研究強化(B)）
  表面弾性波を用いたin situ波形測定による細胞組織の成熟評価AIシステムの構築
  自 2022年, 至 2025年
• 基盤研究(B)
  がん診断治療への最適化を目指したマルチコア構造磁性ナノ粒子の磁化応答モデル構築
  自 2022年, 至 2022年
• 挑戦的研究（萌芽）
  がん転移に関わる細胞分化機構解明を目的とした細胞-細胞間引張強度測定技術の創成
  自 2022年, 至 2022年
• 基盤研究(B)
  重畳化した超音波照射による生体高分子の経皮薬剤送達システムの構築
  自 2021年, 至 2023年
• 基盤研究（A）
  超高速マイクロ液滴衝突現象解明が拓く液滴衝突の新学理とその展開
  自 2025年, 至 2025年
• 基盤研究（A）
  三次元組織の高度成熟化を自律的に達成する知能化培養システム基盤の創出
  自 2025年, 至 2025年

論文

• 超音波アクチュエーション技術によるナノ薬剤投与システムの開発
  倉科佑太
  超音波TECHNO
  2025年09月01日, （MISC）総説・解説（商業誌）
• Enhancement of acoustic cavitation using chitosan nanoparticle-shelled composites
  Xue Xie, Yuta Kurashina, Kyohei Okubo, Hiroyuki Wada, Yoshitaka Kitamoto
  Japanese Journal of Applied Physics
  IOP Publishing Ltd
  Ultrasound cavitation finds diverse applications across biomedical engineering, chemical processes, and industrial systems. Its effects significantly influence the performance of ultrasound imaging and targeted drug delivery. Although microbubbles have been found to enhance cavitation activity, their effect is practically insufficient. To enhance cavitation activity, we introduce a composite structure utilizing chitosan nanoparticles as a stabilizing shell. The relationship between chitosan nanoparticle size and the initial concentrations of chitosan and sodium tripolyphosphate linker is systematically analyzed. The cavitation effect associated with these chitosan nanoparticle-shelled composites is assessed using iodide dosimetry under ultrasonic irradiation at 20 kHz. Composites encapsulated by a positively charged chitosan nanoparticle shell, measuring 23 nm in size, demonstrate significant improvements in hydroxyl radical generation compared to untreated samples, indicating enhanced acoustic cavitation. These findings highlight the potential of combining chitosan nanoparticles with microbubbles for versatile applications ranging from ultrasound imaging to drug delivery.
  2025年02月01日, 研究論文（学術雑誌）, 共同, 64, 2, 0021-4922, DOI(公開)(r-map)
• Hydrogel-polymer hybrid actuator with soft lattice skeleton for excellent connectivity
  Haruna Kozuki, Koki Yoshida, Hiroki Yasuga*, Yuta Kurashina
  Sensors and Actuators B: Chemical
  ELSEVIER SCIENCE SA
  Soft actuators, which integrate stimuli-responsive hydrogels with flexible polymers, have been extensively studied to develop in vivo soft robots for drug delivery systems and non-invasive treatments. However, conventional bilayer actuators, consisting of hydrogel and polymer layers, pose a challenge: the necessity for chemical modification to connect the two layers imposes limitations on the selection of usable materials. This study presents a hydrogel-polymer hybrid actuator comprising a stimuli-responsive hydrogel layer and a hydrogel-polymer hybrid layer with a three-dimensional (3D) porous polymer soft lattice skeleton. The soft lattice skeleton improves connectivity between layers through a mechanical interlock, eliminating the need for chemical modification. A temperature-responsive poly(N-isopropylacrylamide) hydrogel was used as the driving source of the actuator. The soft lattice skeleton was fabricated using multi-directional photolithography. Connectivity improvement was demonstrated by comparing the hybrid actuator to a conventional bilayer actuator after thermal deformation cycles. Specifically, the hybrid actuator maintained connectivity even after multiple cycles, while the bilayer actuator showed complete exfoliation. Deformation behavior was controlled by adjusting the design of the soft lattice skeleton, specifically the width of its constituent micropillars. Curved actuators with various pillar widths exhibited distinct deformation patterns, including bending in the same or opposite direction as the preset curve or twisting. This hybrid actuator design offers improved durability and programmable deformation without chemical modification. It will enable the selection of various hydrogel materials for implementing diverse functions, including pH and glucose sensing. Future research should explore additional structural parameters of the soft lattice skeleton to further control deformation behavior.
  2025年05月01日, 研究論文（学術雑誌）, 共同, 430, DOI(公開)(r-map)
• Hydrogel carrier with bubble vibration enhancer for ultrasound-triggered drug release
  Ryuto Yamakawa, Hiroaki Onoe, Yuta Kurashina
  Ultrasonics Sonochemistry
  2024年11月22日, 研究論文（学術雑誌）, 共同, 112, DOI(公開)(r-map)
• In vitro骨格筋組織の成熟化を促進する電気刺激条件のベイズ最適化による自律的探索
  宮田大輝, 笠原啓太郎, 田口勇仁, 徳岡雄太, 山田貴大, 倉科佑太, 舟橋啓, 尾上弘晃
  電気学会論文誌E
  2025年03月01日, 研究論文（学術雑誌）, 共同, DOI(公開)(r-map)
• Maturation of Human iPSC-Derived Cardiac Microfiber with Electrical Stimulation Device
  Masuda, Akari; Kurashina, Yuta; Tani, Hidenori; Soma, Yusuke; Muramatsu, Jumpei; Itai, Shun; Tohyama, Shugo; Onoe, Hiroaki
  ADVANCED HEALTHCARE MATERIALS
  WILEY
  Here an electrical stimulation system is described for maturing microfiber-shaped cardiac tissue (cardiac microfibers, CMFs). The system enables stable culturing of CMFs with electrical stimulation by placing the tissue between electrodes. The electrical stimulation device provides an electric field covering whole CMFs within the stimulation area and can control the beating of the cardiac microfibers. In addition, CMFs under electrical stimulation with different frequencies are examined to evaluate the maturation levels by their sarcomere lengths, electrophysiological characteristics, and gene expression. Sarcomere elongation (14% increase compared to control) is observed at day 10, and a significant upregulation of electrodynamic properties such as gap junction protein alpha 1 (GJA1) and potassium inwardly rectifying channel subfamily J member 2 (KCNJ2) (maximum fourfold increase compared to control) is observed at day 30. These results suggest that electrically stimulated cultures can accelerate the maturation of microfiber-shaped cardiac tissues compared to those without electrical stimulation. This model will contribute to the pathological research of unexplained cardiac diseases and pharmacologic testing by stably constructing matured CMFs. The electrical stimulation device for cardiac microfibers (CMFs) is designed to promote cardiac tissue maturation. Finite element analysis simulations confirm that a 3D electric field covering whole CMFs is generated in the device. Furthermore, cardiac microfiber cultured under electrical stimulation shows accelerated maturation compared to the nonstimulated group, indicating that this system enables the acquisition of mature cardiac microfibers. image
  2024年10月, 研究論文（学術雑誌）, 共同, 13, 27, 2192-2640, DOI(公開)(r-map)
• Effect of particle size distribution on the transmission efficiency of atomized water to the tracheal tube
  Asakura, Takumi; Yoshioka, Keisuke; Ogawa, Ami; Kurashina, Yuta
  SENSORS AND ACTUATORS A-PHYSICAL
  ELSEVIER SCIENCE SA
  Ultrasonic atomization is a widely used technology. As the atomization device, lead zirconate titanate (PZT) and lithium niobate (LN) are comparatively investigated through experimental and numerical schemes. However, knowledge on a profitable scheme by which to efficiently deliver the atomized particles into the tracheal tube remains unclear. In this study, the physical difference of the transmission efficiency of water particles atomized by PZT and LN devices was measured. The water particles atomized by PZT and LN were injected into a human airway model including a nasal cavity and bronchial tube. The distribution of the amount of transmitted particles deposited at each of the monitoring positions was then estimated using the results of image analysis of color intensity. As a result, the atomized particles of the PZT device, which produced larger particles than the LN device, were more strongly affected by inertia and tended to be deposited at the area closer to the entrance of the nasal cavity. In contrast, the particles produced by the LN device tended to be transmitted deeper into the trachea. The experimental results indicated that the particle size distribution of PZT and LN, which have quite different maximum sizes of particles, largely influences the spatial distribution characteristics of particle deposition along the airway from the nasal cavity to the trachea.
  2024年05月01日, 研究論文（学術雑誌）, 共同, 370, 0924-4247, DOI(公開)(r-map)
• Adeno-Associated Virus-Encapsulated Alginate Microspheres Loaded in Collagen Gel Carriers for Localized Gene Transfer
  Kurashina, Yuta; Kurihara, Sho; Kubota, Takeshi; Takatsuka, Shuhei; Hirabayashi, Motoki; Shimmura, Hajime; Miyahara, Hideo; Hioki, Aiki; Matsushita, Yutaka; Muramatsu, Jumpei; Ogawa, Yuki; Fujioka, Masato; Okano, Hirotaka J.; Onoe, Hiroaki
  ADVANCED HEALTHCARE MATERIALS
  WILEY
  This work reports localized in vivo gene transfer by biodegradation of the adeno-associated virus-encapsulating alginate microspheres (AAV-AMs) loaded in collagen gel carriers. AAV-AMs are centrifugally synthesized by ejecting a mixed pre-gel solution of alginate and AAV to CaCl2 solution to form an ionically cross-linked hydrogel microsphere immediately. The AAV-AMs are able to preserve the AAV without diffusing out even after spreading them on the cells, and the AAV is released and transfected by the degradation of the alginate microsphere. In addition, AAV-AMs can be stored by cryopreservation until use. By implanting this highly convenient AAV-encapsulated hydrogel, AAV-AMs can be loaded into collagen gel carriers to fix the position of the implanted AAV-AMs and achieve localized gene transfer in vivo. In vivo experiments show that the AAV-AMs loaded in collagen gel carriers are demonstrated to release the encapsulated AAV for gene transfer in the buttocks muscles of mice. While conventional injections caused gene transfer to the entire surrounding tissue, the biodegradation of AAV-AMs shows that gene transfer is achieved locally to the muscles. This means that the proposed AAV-loaded system is shown to be a superior method for selective gene transfer. The adeno-associated virus-encapsulated alginate microspheres loaded in collagen gel carrier (AAV-AMs-LCC) are synthesized to control gene transfer of AAV into target tissues. The preservation and release performance of AAV-AMs is demonstrated by spreading AAV-AMs on the cells. Additionally, implantation of AAV-AMs-LCCs in skeletal muscle of mice allows localized gene transfer by releasing AAV through biodegradation of AAV-AMs. image
  2024年05月, 研究論文（学術雑誌）, 共同, 13, 12, 2192-2640, DOI(公開)(r-map)
• Hydrogel-Sheathed Hipsc-Derived Heart Microtissue Enables Anchor-Free Contractile Force Measurement
  Kurashina, Yuta; Fukada, Keisuke; Itai, Shun; Akizuki, Shuichi; Sato, Ryo; Masuda, Akari; Tani, Hidenori; Fujita, Jun; Fukuda, Keiichi; Tohyama, Shugo; Onoe, Hiroaki
  ADVANCED SCIENCE
  WILEY
  In vitro reconstruction of highly mature engineered heart tissues (EHTs) is attempted for the selection of cardiotoxic drugs suitable for individual patients before administration. Mechanical contractile force generated in the EHTs is known to be a critical indicator for evaluating the EHT response. However, measuring contractile force requires anchoring the EHT in a tailored force-sensing cell culture chamber, causing technical difficulties in the stable evaluation of contractile force in long-term culture. This paper proposes a hydrogel-sheathed human induced pluripotent stem cell (hiPSC)-derived heart microtissue (H3M) that can provide an anchor-free contractile force measurement platform in commonly used multi-well plates. The contractile force associated with tissue formation and drug response is calculated by motion tracking and finite element analysis on the bending angle of the hydrogel sheath. From the experiment of the drug response, H3M is an excellent drug screening platform with high sensitivity and early testing capability compared to conventionally anchored EHT. This unique platform would be useful and versatile for regenerative therapy and drug discovery research in EHT.
  2023年12月, 研究論文（学術雑誌）, 共同, 10, 35, DOI(公開)(r-map)
• Spatiotemporal single-cell tracking analysis in 3D tissues to reveal heterogeneous cellular response to mechanical stimuli
  Kasahara, Keitaro; Muramatsu, Jumpei; Kurashina, Yuta; Miura, Shigenori; Miyata, Shogo; Onoe, Hiroaki
  SCIENCE ADVANCES
  AMER ASSOC ADVANCEMENT SCIENCE
  Mechanical stimuli have been recognized as important for tissue maturation, homeostasis and constructing engineered three-dimensional (3D) tissues. However, we know little about the cellular mechanical response in tissues that could be considerably heterogeneous and spatiotemporally dynamic due to the complex structure of tissues. Here, we report a spatiotemporal single-cell tracking analysis of in vitro 3D tissues under mechanical stretch, to reveal the heterogeneous cellular behavior by using a developed stretch and optical live imaging system. The system could affect the cellular orientation and directly measure the distance of cells in in vitro 3D myoblast tissues (3DMTs) at the single-cell level. Moreover, we observed the spatiotemporal heterogeneous cellular locomotion and shape changes under mechanical stretch in 3DMTs. This single-cell tracking analysis can become a principal method to investigate the heterogeneous cellular response in tissues and provide insights that conventional analyses have not yet offered.
  2023年10月13日, 研究論文（学術雑誌）, 共同, 9, 41, 2375-2548, DOI(公開)(r-map)
• Controlled release of adeno-associated virus from alginate hydrogel microbeads with enhanced sensitivity to ultrasound
  Takatsuka, Shuhei; Kubota, Takeshi; Kurashina, Yuta; Kurihara, Sho; Hirabayashi, Motoki; Fujioka, Masato; Okano, Hirotaka James; Onoe, Hiroaki
  BIOTECHNOLOGY AND BIOENGINEERING
  WILEY
  Adeno-associated virus (AAV)-based gene therapy holds promise as a fundamental treatment for genetic disorders. For clinical applications, it is necessary to control AAV release timing to avoid an immune response to AAV. Here we propose an ultrasound (US)-triggered on-demand AAV release system using alginate hydrogel microbeads (AHMs) with a release enhancer. By using a centrifuge-based microdroplet shooting device, the AHMs encapsulating AAV with tungsten microparticles (W-MPs) are fabricated. Since W-MPs work as release enhancers, the AHMs have high sensitivity to the US with localized variation in acoustic impedance for improving the release of AAV. Furthermore, AHMs were coated with poly-l-lysine (PLL) to adjust the release of AAV. By applying US to the AAV encapsulating AHMs with W-MPs, the AAV was released on demand, and gene transfection to cells by AAV was confirmed without loss of AAV activity. This proposed US-triggered AAV release system expands methodological possibilities in gene therapy.
  2023年08月, 研究論文（学術雑誌）, 共同, 120, 8, 0006-3592, DOI(公開)(r-map), 2371, 2377
• Schwann cell-encapsulated chitosan-collagen hydrogel nerve conduit promotes peripheral nerve regeneration in rodent sciatic nerve defect models
  Takeya, Hiroaki; Itai, Shun; Kimura, Hiroo; Kurashina, Yuta; Amemiya, Tsuyoshi; Nagoshi, Narihito; Iwamoto, Takuji; Sato, Kazuki; Shibata, Shinsuke; Matsumoto, Morio; Onoe, Hiroaki; Nakamura, Masaya
  SCIENTIFIC REPORTS
  NATURE PORTFOLIO
  Chitosan has various tissue regeneration effects. This study was designed to investigate the nerve regeneration effect of Schwann cell (SC)-encapsulated chitosan-collagen hydrogel nerve conduit (CCN) transplanted into a rat model of sciatic nerve defect. We prepared a CCN consisting of an outer layer of chitosan hydrogel and an inner layer of collagen hydrogel to encapsulate the intended cells. Rats with a 10-mm sciatic nerve defect were treated with SCs encapsulated in CCN (CCN+), CCN without SCs (CCN-), SC-encapsulated silicone tube (silicone+), and autologous nerve transplanting (auto). Behavioral and histological analyses indicated that motor functional recovery, axonal regrowth, and myelination of the CCN+ group were superior to those of the CCN- and silicone+ groups. Meanwhile, the CCN- and silicone+ groups showed no significant differences in the recovery of motor function and nerve histological restoration. In conclusion, SC-encapsulated CCN has a synergistic effect on peripheral nerve regeneration, especially axonal regrowth and remyelination of host SCs. In the early phase after transplantation, SC-encapsulated CCNs have a positive effect on recovery. Therefore, using SC-encapsulated CCNs may be a promising approach for massive peripheral nerve defects.
  2023年07月24日, 研究論文（学術雑誌）, 共同, 13, 1, 2045-2322, DOI(公開)(r-map)
• Mechanical effect of reconstructed shapes of autologous ossicles on middle ear acoustic transmission
  Asakura, Takumi; Ito, Ryuya; Hirabayashi, Motoki; Kurihara, Sho; Kurashina, Yuta
  FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
  FRONTIERS MEDIA SA
  Conductive hearing loss is caused by a variety of defects, such as chronic otitis media, osteosclerosis, and malformation of the ossicles. In such cases, the defective bones of the middle ear are often surgically reconstructed using artificial ossicles to increase the hearing ability. However, in some cases, the surgical procedure does not result in increased hearing, especially in a difficult case, for example, when only the footplate of the stapes remains and all of the other bones are destroyed. Herein, the appropriate shapes of the reconstructed autologous ossicles, which are suitable for various types of middle-ear defects, can be determined by adopting an updating calculation based on a method that combines numerical prediction of the vibroacoustic transmission and optimization. In this study, the vibroacoustic transmission characteristics were calculated for bone models of the human middle ear by using the finite element method (FEM), after which Bayesian optimization (BO) was applied. The effect of the shape of artificial autologous ossicles on the acoustic transmission characteristics of the middle ear was investigated with the combined FEM and BO method. The results suggested that the volume of the artificial autologous ossicles especially has a great influence on the numerically obtained hearing levels.
  2023年06月22日, 研究論文（学術雑誌）, 共同, 11, 2296-4185, DOI(公開)(r-map)
• Can nanoparticles enhance drug-delivery performance of hydrogels?
  Rossi, Filippo; Kurashina, Yuta; Onoe, Hiroaki
  NANOMEDICINE
  FUTURE MEDICINE LTD
  2023年04月, 研究論文（学術雑誌）, 共同, 18, 8, 1743-5889, DOI(公開)(r-map), 653, 657
• A Novel Rat Model of Embolic Cerebral Ischemia Using a Cell-Implantable Radiopaque Hydrogel Microfiber
  Komatsu, Teppei; Ohta, Hiroki; Takakura, Naoki; Hata, Junichi; Kitagawa, Tomomichi; Kurashina, Yuta; Onoe, Hiroaki; Okano, Hirotaka James; Iguchi, Yasuyuki
  TRANSLATIONAL STROKE RESEARCH
  SPRINGER
  The failure of neuroprotective treatment-related clinical trials, including stem cell therapies, may be partially due to a lack of suitable animal models. We have developed a stem cell-implantable radiopaque hydrogel microfiber that can survive for a long time in vivo. The microfiber is made of barium alginate hydrogel containing zirconium dioxide, fabricated in a dual coaxial laminar flow microfluidic device. We aimed to develop a novel focal stroke model using this microfiber. Using male Sprague-Dawley rats (n=14), a catheter (inner diameter, 0.42 mm; outer diameter, 0.55 mm) was navigated from the caudal ventral artery to the left internal carotid artery using digital subtraction angiography. A radiopaque hydrogel microfiber (diameter, 0.4 mm; length, 1 mm) was advanced through the catheter by slow injection of heparinized physiological saline to establish local occlusion. Both 9.4-T magnetic resonance imaging at 3 and 6 h and 2% 2,3,5-triphenyl tetrazolium chloride staining at 24 h after stroke model creation were performed. Neurological deficit score and body temperature were measured. The anterior cerebral artery-middle cerebral artery bifurcation was selectively embolized in all rats. Median operating time was 4 min (interquartile range [IQR], 3-8 min). Mean infarct volume was 388 mm(3) (IQR, 354-420 mm(3)) at 24 h after occlusion. No infarction of the thalamus or hypothalamus was seen. Body temperature did not change significantly over time (P = 0.204). However, neurological deficit scores before and at 3, 6, and 24 h after model creation differed significantly (P < 0.001). We present a novel rat model of focal infarct restricted to the middle cerebral artery territory using a radiopaque hydrogel microfiber positioned under fluoroscopic guidance. By comparing the use of stem cell-containing versus non-containing fibers in this stroke model, it would be possible to determine the efficacy of pure cell transplantation in treating stroke.
  2023年03月03日, 研究論文（学術雑誌）, 共同, 1868-4483, DOI(公開)(r-map)
• Acoustic-responsive carbon dioxide-loaded liposomes for efficient drug release
  Orita, Yasuhiko; Shimanuki, Susumu; Okada, Satoshi; Nakamura, Kentaro; Nakamura, Hiroyuki; Kitamoto, Yoshitaka; Shimoyama, Yusuke; Kurashina, Yuta
  ULTRASONICS SONOCHEMISTRY
  ELSEVIER
  The role of liposomes as drug carriers has been investigated. Ultrasound-based drug release methods have been developed for on-demand drug delivery. However, the acoustic responses of current liposome carriers result in low drug release efficiency. In this study, CO2-loaded liposomes were synthesized under high pressure from supercritical CO2 and irradiated with ultrasound at 237 kHz to demonstrate their superior acoustic respon-siveness. When liposomes containing fluorescent drug models were irradiated with ultrasound under acoustic pressure conditions that are safe for the human body, CO2-loaded liposomes synthesized using supercritical CO2 had 17.1 times higher release efficiency than liposomes synthesized using the conventional Bangham method. In particular, the release efficiency of CO2-loaded liposomes synthesized using supercritical CO2 and mono-ethanolamine was 19.8 times higher than liposomes synthesized using the conventional Bangham method. These findings on the release efficiency of acoustic-responsive liposomes suggest an alternative liposome synthesis strategy for on-demand release of drugs by ultrasound irradiation in future therapies.
  2023年03月, 研究論文（学術雑誌）, 共同, 94, 1350-4177, DOI(公開)(r-map)
• Near-Infrared-Triggered On-Demand Controlled Release of Adeno-Associated Virus from Alginate Hydrogel Microbeads with Heat Transducer for Gene Therapy
  Takatsuka, Shuhei; Kubota, Takeshi; Kurashina, Yuta; Onoe, Hiroaki
  SMALL
  WILEY
  Gene therapy using adeno-associated virus (AAV) has potential as a radical treatment modality for genetic diseases such as sensorineural deafness. To establish clinical applications, it is necessary to avoid immune response to AAV by controlled release system of AAV. Here, a near-infrared (NIR)-triggered on-demand AAV release system using alginate hydrogel microbeads with a heat transducer is proposed. By using a centrifuge-based microdroplet shooting device, the microbeads encapsulating AAV with Fe3O4 microparticles (Fe3O4-MPs) as a heat transducer are fabricated. Fe3O4-MPs generated heat by NIR enhanced the diffusion speed of the AAV, resulting in the AAV being released from the microbeads. By irradiating the microbeads encapsulating fluorescent polystyrene nanoparticles (FP-NPs) (viral model) with NIR, the fluorescence intensity decreased only for FP-NPs with a diameter of 20 nm and not for 100 or 200 nm, confirming that this system can release virus with a diameter of several tens of nanometers. By irradiating NIR to the AAV-encapsulating microbeads with Fe3O4-MPs, the AAV is released on demand, and gene transfection to cells by AAV is confirmed without loss of viral activity. The NIR-triggered AAV release system proposed in this study increases the number of alternatives for the method of drug release in gene therapy.
  2023年02月, 研究論文（学術雑誌）, 共同, 19, 7, 1613-6810, DOI(公開)(r-map)
• Synthesis and characterization of pH-responsive ferrogels comprising sulfamethazine-based polymer and magnetic nanoparticles for sensing ammonia gas
  JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
  ELSEVIER
  Ferrogels have been widely used in soft actuators and as carriers in drug delivery systems owing to their responsiveness to magnetic stimulus. Herein, a novel ferrogel that exhibits chemically modulated magnetism is synthesized, by dispersing magnetic nanoparticles (MNPs) in a hydrogel produced from a pH-responsive sulfa-methazine-based polymer during polymerization and cross-linking. The MNPs exhibit dynamic rotations or os-cillations in the rheological matrix under alternating current (AC) magnetic fields. The AC magnetization behavior of the incorporated MNPs is modulated by the swelling of the hydrogel in response to changes in pH over the range of 7-12. The ferrogels with larger swelling ratios exhibit enhanced Brownian relaxation during AC magnetization. Based on the pH response of the AC magnetization, the detection of ammonia gas is investigated using the ferrogel as a sensing label, and the sensitivity of 5.3 x 10-6 mol/L or lower has been achieved. Therefore, the as-prepared ferrogel is suitable for use as a sensing label in applications such as the sensing of ammonia emitted from human skin for health monitoring.
  2023年01月01日, 研究論文（学術雑誌）, 共同, 565, 170201, 0304-8853, DOI(公開)(r-map)
• Combined analysis of finite element model and audiometry provides insights into the pathogenesis of conductive hearing loss
  Hirabayashi, Motoki; Kurihara, Sho; Ito, Ryuya; Kurashina, Yuta; Motegi, Masaomi; Okano, Hirotaka James; Yamamoto, Yutaka; Kojima, Hiromi; Asakura, Takumi
  FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
  FRONTIERS MEDIA SA
  The middle ear transmits sound to the inner ear via vibrations in the eardrum and ossicles, and damage to the middle ear results in conductive hearing loss. Although conductive hearing loss can be corrected by surgery, the currently available clinical investigations cannot always diagnose the ossicular chain pathology underlying the conductive hearing loss, and even intraoperative findings can be equivocal. Acoustic analysis using finite element models (FEMs) can simulate the sound pressure change at an arbitrary site for each frequency. FEMs are used in acoustic engineering to simulate the frequency-dependent sound pressure distribution at discrete cells in a simulated model and analyze the effects of specific parameters on the audiogram. However, few reports have compared the numerical results obtained using FEMs with data from clinical cases. We used FEMs to simulate audiograms of the air-bone gap (ABG) for various ossicular chain defects and compared these with preoperative audiograms obtained from 44 patients with a normal tympanic membrane who had otosclerosis, middle ear malformations or traumatic ossicular disruption. The simulated audiograms for otosclerosis and attic fixation of the malleus-incus complex both exhibited an up-slope but could be distinguished from each other based on the ABG at 1000 Hz. The simulated audiogram for incudostapedial joint discontinuity exhibited a peak at around 750 Hz and a down-slope above 1000 Hz. In general, the simulated audiograms for otosclerosis, attic fixation and incudostapedial joint discontinuity were consistent with those obtained from clinical cases. Additional simulations indicated that changes in ossicular mass had relatively small effects on ABG. Furthermore, analyses of combination pathologies suggested that the effects of one defect on ABG were added to those of the other defect. These FEM-based findings provide insights into the pathogenesis of conductive hearing loss due to otosclerosis, middle ear malformations and traumatic injury.
  2022年09月02日, 研究論文（学術雑誌）, 共同, 10, 2296-4185, DOI(公開)(r-map)
• Transdermal delivery of bFGF with sonophoresis facilitated by chitosan nanocarriers
  Xie, Xue; Kurashina, Yuta; Matsui, Makoto; Nomoto, Takahiro; Itoh, Munenari; Okano, Hirotaka J.; Nakamura, Kentaro; Nishiyama, Nobuhiro; Kitamoto, Yoshitaka
  JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY
  ELSEVIER
  The basic fibroblast growth factor (bFGF) is a potent angiogenic growth factor. Supplemental bFGF is essential for healing damaged skin, but its therapeutic use has been limited owing to its inherent instability. In this study, we propose a transdermal delivery system using sonophoresis along with the use of carboxymethyl chitosan nanocarriers which enables the administration of bFGF over a wide area of skin. The transdermal effect of the low-frequency ultrasound-enhanced delivery system was demonstrated in ex vivo experiments using hairless mouse skin. The subcutaneous administration of chitosan nanoparticles was evaluated by using fluorescencelabeled chitosan. To stably load bFGF into chitosan nanoparticles, a carrier with carboxymethyl chitosan was synthesized under a pH of around 7. Based on the results, we evaluated the effectiveness of transdermal drug delivery using sonophoresis. In skin cryosections, bFGF-loaded carboxymethyl chitosan nanocarriers delivered by ultrasound irradiation were present subcutaneously. We analyzed the bFGF content in skin tissue by ELISA and found that bFGF penetration in skin irradiated by ultrasound with nanocarriers. Penetration of bFGF-leaded carboxymethyl chitosan nanocarriers by ultrasound was significantly higher than that by ultrasound irradiation alone. Our results lay the groundwork for further utilization of polymeric nanocarriers using sonophoresis for the administration of biomacromolecules.
  2022年09月, 研究論文（学術雑誌）, 共同, 75, 1773-2247, DOI(公開)(r-map)
• Vascular embolization of radiopaque hydrogel microfiber using ultra-minimally invasive technique for stage-adjustable renal failure model
  Takakura, Naoki; Ohta, Hiroki; Komatsu, Teppei; Kurashina, Yuta; Hiroka, Yuya; Okano, Hirotaka J.; Onoe, Hiroaki
  MATERIALS & DESIGN
  ELSEVIER SCI LTD
  Animal pathology models play an important role in elucidating pathology, evaluating drug efficacy, and studying therapeutic. This paper presents the creation of rats' renal failure model by embolizing the renal artery using radiopaque hydrogel microfibers. By using a dual coaxial laminar flow microfluidic device, barium alginate gel microfibers containing zirconia particles were fabricated. Since the zirconia particles are radiopaque, the microfiber can be delivered and embolized while confirming the position of the microfiber in real-time under X-ray imaging. The delivery of microfibers through a catheter into the renal artery of rats to create a renal failure model was tested. The radiopaque microfibers were visualized by X-ray imaging when delivered by a catheter. Furthermore, the microfibers remained stable for 2 weeks after delivery. In addition, by adjusting the number of microfibers, two different rat models with severe and mild renal failure conditions were created. The proposed delivery of radiopaque hydrogel microfibers to create an embolization model is expected to be an effective approach to control the degree of symptoms and elucidate the pathology. (c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
  2022年07月, 研究論文（学術雑誌）, 共同, 219, 0264-1275, DOI(公開)(r-map)
• A novel fabrication process of up-scalable microfiber-shaped tendon-like tissue with high cell density for uniformed macroscale assembly
  Fukada, Keisuke; Tachibana, Koji; Kurashina, Yuta; Kaneko, Yosuke; Matsumoto, Tatsuaki; Miyamoto, Takeshi; Niki, Yasuo; Nakamura, Masaya; Onoe, Hiroaki
  BIOTECHNOLOGY AND BIOENGINEERING
  WILEY
  This paper describes up-scalable microfiber-shaped tissues for macroscale tendon tissue reconstruction in vitro. C3H10T1/2 cells were encapsulated in a calcium alginate hydrogel microfiber that was fabricated via a double coaxial microfluidic device. The C3H10T1/2 cells gradually merged to construct the microfiber-shaped tendon-like tissue. Our microfiber-shaped tendon-like tissues were alive and maintained their microfiber-shaped morphology over 600 days. Immunostaining and real-time quantitative polymerase chain reaction analyses showed that our fabricated microfiber-shaped tendon-like tissue properly expressed tenomodulin and the orientation of the filaments of actin, which are one of the characteristics of tendon tissue in vivo. Furthermore, a macroscale tendon tissue assembly with similar to 1 cm in length and similar to 200 mu m in thickness was successfully constructed by bundling the microfiber-shaped tendon-like tissues together. This feature enabled us to fabricate a macroscale tendon tissue with uniform cell distribution. We believe that our fabricated microfiber-shaped tendon-like tissue would be a suitable strategy to reconstruct tendon tissue in vitro for the treatments of tendon-related injuries.
  2022年05月, 研究論文（学術雑誌）, 共同, 119, 5, 0006-3592, DOI(公開)(r-map), 1327, 1336
• QUANTITATIVE ANALYSIS OF ACOUSTIC PRESSURE FOR SONOPHORESIS AND ITS EFFECT ON TRANSDERMAL PENETRATION
  Kurashina, Yuta; Asano, Risa; Matsui, Makoto; Nomoto, Takahiro; Ando, Keita; Nakamura, Kentaro; Nishiyama, Nobuhiro; Kitamoto, Yoshitaka
  ULTRASOUND IN MEDICINE AND BIOLOGY
  ELSEVIER SCIENCE INC
  Ultrasound facilitates the penetration of macromolecular compounds through the skin and offers a promising non-invasive technique for transdermal delivery. However, technical difficulties in quantifying ultrasound-related parameters have restricted further analysis of the sonophoresis mechanism. In this study, we devise a bolt-clamped Langevin transducer-based sonophoresis device that enables us to measure with a thin lead zirconate titanate (PZT) sensor. One-dimensional acoustic theory accounting for wave interaction at the skin interface indicates that the acoustic pressure and cavitation onset on the skin during sonophoresis are sensitive to the subcutaneous support, meaning that there is a strong need to perform the pressure measurement in an experimental environment replacing the human body. From a series of the experiments with our new device, the transdermal penetration of polystyrene, silica and gold nanoparticles is found to depend on the size and material of the particles, as well as the hardness of the subcutaneous support material. We speculate from the acoustic pressure measurement that the particles' penetration results from the mechanical action of cavitation.(E-mail: kurashina@mac.titech.ac.jp) (c) 2022 World Federation for Ultrasound in Medicine & Biology. All rights reserved.
  2022年05月, 研究論文（学術雑誌）, 共同, 48, 5, 0301-5629, DOI(公開)(r-map), 933, 944
• Effect of the area of a lithium niobate transducer on the efficiency of ultrasonic atomization driven by resonance vibration
  Yoshioka, Keisuke; Kurashina, Yuta; Ogawa, Ami; Asakura, Takumi
  ULTRASONICS SONOCHEMISTRY
  ELSEVIER
  In recent years, individual control of one's personal environment has been drawing increasing attention due to the growing interest in health care. Wearable devices are especially useful because of their controllability regardless of location. Humidity is one of the inevitable factors in the personal environment as a preventive against infectious diseases. Although atomization devices are commonly used as a method of humidity control, at present, there are no wearable humidity control devices. Vibration of a lithium niobate (LN) device in the thickness mode is a promising piezoelectric method for miniaturization of atomization devices for humidity control. To miniaturize the atomization device, the transducer size needs to be small not so much as to decrease the atomization efficiency. However, the effect of the device area on the atomization efficiency of LN at a size suitable for mounting in wearable devices has not been studied. Here, we conducted an atomization demon-stration of LN devices with different sizes to evaluate particle size and atomization efficiency. Furthermore, to reveal the relationship between vibration behavior and atomization efficiency, resonance vibration in the MHz frequency band was evaluated by the finite element method and an impedance analyzer. The results showed that the peak size of water particles atomized by each device was in the range of 3.2 to 4.2 mu m, which is smaller than particles produced by typical piezoelectric ceramics. Moreover, the best LN size for efficient atomization was found to be 8 mm x 10 mm among the five LN device sizes used in experiments. From the relationship between vibration behavior and atomization efficiency, the size of the transducer was suggested to affect the vibration mode. The obtained result suggested that the LN device is suitable for small wearable nebulizer devices.
  2022年05月, 研究論文（学術雑誌）, 共同, 86, 1350-4177, DOI(公開)(r-map)
• Spheroid Cell Aggregation Enhanced by Enzyme-Free Ultrasound-Detached Cells
  van Delft, Julien; Imashiro, Chikahiro; Kurashina, Yuta; Hirano, Makoto; Homma, Jun; Mochizuki, Shinsuke; Shimozawa, Hideharu; Takemura, Kenjiro
  ADVANCED BIOLOGY
  WILEY-V C H VERLAG GMBH
  Spheroids are being widely studied as potential building blocks for complex organ engineering, tools for drug screening and cancer study. However, formation time has become the bottleneck of applications due to the need for large-scale high-quality spheroids production. Formation time is often dominated by ECM construction and not cell aggregation. Therefore, this study focuses on the influence of ultrasound detachment replacing conventional enzyme detachment on spheroid formation processes. Thanks to cell surface protein preservation in ultrasound detachment, cell aggregation time is reduced while decreasing the formation variabilities. Moreover, it is confirmed that cells are intrinsically more capable of aggregating through enzyme-free detachment. On top of that, transplantations into rats showed equally successful engraftment properties for enzyme-free detached cells. Finally, the impact on the real co-cultured spheroid application was shown to be beneficial through more localized cell groups inside of the spheroids, possibly improving therapeutic effects and vascularization. Through this study, it is proved that ultrasound detachment can replace enzyme detachment without degrading the final spheroid properties but reducing the formation time, and variability and improving robustness and cell distribution. This opens up a new range of applications for better and faster spheroid formation in numerous bioengineering applications.
  2025年08月, 研究論文（学術雑誌）, 共同, 9, 8, 2701-0198, DOI(公開)(r-map)
• Scaling Effects on Single-Cell Manipulation Using Magnetic Forces at Edge of Flat Plate With Elliptically Micro-Projection
  Ota, Satoshi; Yasuga, Hiroki; Akagawa, Takeshi; Kurashina, Yuta; Nakazawa, Kenta; Kikuchi, Shoichi
  BIOTECHNOLOGY AND BIOENGINEERING
  WILEY
  Single-cell manipulation is needed for various cellular analyses and biomedical applications. In the conventional single-cell manipulation methodology, cells are the center of a flat dish or hollow space, where the medium spontaneously penetrates. However, manipulation at the edge of the plate, where the flow of the medium is interrupted by its surface tension, has not yet been shown. In this study, we manipulated single cells labeled with magnetic nanoparticles at the edge of a projecting microfabricated plate under a magnetic field, which offer a less invasive method for cellular analyses, not limited by the shape of the culture devices. As a cell is affected by both the surface tension of the medium and magnetic force, we investigated the effects of the shape and scale of the projection on cell motion. Owing to energy minimization between the liquid-air and solid-liquid interfaces determined by the structure of the projection, the area of solution spreading in the projection converged, and we obtained design guidelines for the projection that enabled cell manipulation. Demonstrating accuracy in single-cell manipulation on a microfabricated flat plate with different projection shapes contributes to developing single-cell analyses, including applications such as single-cell-based polymerase chain reactions.
  2025年12月, 研究論文（学術雑誌）, 共同, 122, 12, 0006-3592, DOI(公開)(r-map), 3355, 3365
• M/G-Ratio-Tuned Calcium Alginate Hydrogel Microcarrier for Controlled Delivery of Adeno-Associated Virus for Gene Therapy
  Hioki, Aiki; Takatsuka, Shuhei; Kurashina, Yuta; Onoe, Hiroaki
  BIOTECHNOLOGY AND BIOENGINEERING
  WILEY
  This paper proposes the controlled release of adeno-associated virus (AAV) by polymer mesh structures of alginate hydrogel microbeads (gel-beads). The polymer mesh structure of alginate hydrogel can be controlled by adjusting the number of cross-linking points depending on the molecular structure (M/G ratio) of the alginate hydrogel. Scanning electron microscopic analysis on the mesh structures of alginate hydrogels with M/G ratios of 0.96 (MG-0.96) and 0.42 (MG-0.42) indicates that the mesh size distribution of MG-0.42 hydrogel was smaller than that of MG-0.96 hydrogel. Using these characteristics, controlled release of AAVs (AAV-1 or AAV-5) from M/G-ratio-tuned gel-beads (MG-0.96 or MG-0.42), Janus-shaped gel-beads consisting of hemispheres of the MG-0.96 and MG-0.42, and MG-0.64 gel-beads consisting of a mixture of MG-0.96 and MG-0.42 were examined with ELISA for AAV capsids and the GFP fluorescent signals from the transfected cells. The precise control of AAV release by the mesh structure of the alginate hydrogels could be an effective method for creating AAV micro-carriers for gene therapy.
  2025年12月, 研究論文（学術雑誌）, 共同, 122, 12, 0006-3592, DOI(公開)(r-map), 3433, 3445
• Influence of Exposure Time and Driving Frequency on Cytotoxicity in In Vitro Ultrasound With Constant Mechanical Indices
  Oyama, Taigo; Imashiro, Chikahiro; Kurashina, Yuta; Ando, Keita; Takemura, Kenjiro
  ENGINEERING IN LIFE SCIENCES
  WILEY
  Sonochemistry has become increasingly important in bioengineering research, and many in vitro and in vivo bioapplications have been developed. Cytotoxicity is always a concern in its implementation. For in vivo treatments and studies, mechanical index (MI) is known to ensure biocompatibility, and even in vitro MI has been used. Because cell characteristics and acoustic phenomena differ in vitro and in vivo, we questioned using MI in vitro. The in vitro cytotoxicity of ultrasound exposure should be investigated to support the development of cutting-edge sonochemistry. In this study, a system for irradiating cultured cells with 1-2 MHz-range ultrasound was developed to demonstrate the invalidity of employing MI alone in vitro. The results showed that cell damage is defined by the MI, ultrasound frequency, and exposure time, which are new indices for quantifying cell damage. Furthermore, cavitation and acoustic streaming are shown to be the main scientific factors that injure cells.
  2025年05月, 研究論文（学術雑誌）, 共同, 25, 5, 1618-0240, DOI(公開)(r-map)
• Synthesis of Hydrogel Microparticles from Ultra-High-Viscosity Pre-Gel Solution by Combining Centrifugal Force and Ultrasonic Vibration
  Bando, Yuta; Kawamae, Ryota; Konno, Ru; Onoe, Hiroaki; Tagawa, Yoshiyuki; Kurashina, Yuta
  SMALL
  WILEY-V C H VERLAG GMBH
  Viscosity is a key physical parameter influencing droplet generation. Herein, the synthesis of hydrogel microparticles from an ultra-high-viscosity pre-gel (UHV-HMPs) solution using a microparticle synthesis device combining centrifugal force with ultrasonic vibration (MSDCU) is reported. The advantage of MSDCU is that it can synthesize closely spherical microparticles from ultra-high-viscosity pre-gel solutions with viscosities exceeding 104 mPas in the air/water method. The ultrasonic droplet-shooting module embedded in the MSDCU ejects an ultra-high-viscosity pre-gel solution of sodium alginate through a capillary under ultrasonic vibration to overcome the viscosity limitations of using only centrifugal force. Based on an evaluation of the vibration modes of a multilayer transducer with a capillary at various resonance frequencies, a vibration mode with longitudinal and lateral vibrations of 100 kHz is selected. The combination of ultrasonic vibration at 100 kHz and a centrifugal force of 230g results in the ejection of pre-gel solution with a maximum viscosity of 1.5 x 105 mPas. At a viscosity of 1.5 x 104 mPas, control of the distance between the capillary and crosslinking solution improves particle circularity, enabling the formation of spherical UHV-HMPs with a diameter of approximate to 140 mu m. With a higher viscosity solution (3.0 x 104 mPas), smaller homogeneous satellite particles with a diameter of approximate to 31 mu m are synthesized after filtering.
  2025年08月, 研究論文（学術雑誌）, 共同, 21, 34, 1613-6810, DOI(公開)(r-map)
• Transdermal administration of macromolecular drugs by multi-frequency sequential ultrasonic irradiation
  Matsubara, Kengo; Konosu, Daichi; Itoh, Munenari; Okano, Hirotaka J.; Nakamura, Kentaro; Kurashina, Yuta
  INTERNATIONAL JOURNAL OF PHARMACEUTICS
  ELSEVIER
  Administration methods of macromolecular drugs with high efficacy and minimal side effects are generally limited to highly invasive injections due to their components and large molecular weight. Here, we propose a sequential ultrasonic irradiation method using multi-frequency for minimally invasive administration of macromolecular drugs. In this demonstration, low-frequency ultrasound (kHz band) and high-frequency ultrasound (MHz band) were sequentially irradiated onto the porcine skin to evaluate the dosing efficiency using fluorescence-modified ovalbumin (Mw = 45 kDa), a macromolecular drug model. Quantitative evaluation of the transdermal dosage by fluorescence intensity measurement shows that the proposed method significantly increased the transdermal dosage by almost double that of the conventional method. In particular, the distance of MHz ultrasonic irradiation is indicated to influence the dosing efficiency. In addition, the evaluation of transdermal permeability by confocal observation of skin sections shows that the macromolecular drug model penetrates through the epidermis of porcine skin, including the stratum corneum, to the dermis layer with the proposed method. The proposed method permeated the drug model with a behavior correlated to the intensity of the MHz ultrasonic beam, as opposed to the discrete penetration of the drug model in the conventional method. Our results provide a minimally invasive method of administering macromolecular drugs as an alternative to injection.
  2025年04月30日, 研究論文（学術雑誌）, 共同, 675, 0378-5173, DOI(公開)(r-map)
• High-resolution pressure imaging via background-oriented schlieren tomography: A spatiotemporal measurement for MHz ultrasound fields and hydrophone calibration
  Ichihara, Sayaka; Yamagishi, Masato; Kurashina, Yuta; Ota, Masanori; Tagawa, Yoshiyuki
  ULTRASONICS
  ELSEVIER
  In this work, the spatiotemporal pressure field of MHz-focused ultrasound is measured using a background- oriented schlieren technique combined with fast checkerboard demodulation and vector tomography (VT-BOS). Hydrophones have been commonly employed to directly measure the local pressure in underwater ultrasound. However, their limitations include that they disturb the acoustic field and affect the measured pressure through the spatial averaging effect. To overcome such limitations, we propose VT-BOS as a non-contact technique for acoustic field measurements using only a background image and a camera. In our experiments, VT-BOS measures focused acoustic fields with a focal width of 1.0 mm and a frequency of 4.55 MHz, capturing traveling, reflected, and standing waves. We discuss three key features of this approach: (1) the temporal evolution of pressure measured by VT-BOS and hydrophones, (2) the differences in computational cost and spatial resolution between VT-BOS and other techniques, and (3) the measurement range of VT-BOS. The results demonstrate that VT-BOS successfully quantifies spatiotemporal acoustic fields and can estimate the hydrophones' spatial averaging effect over a finite area. VT-BOS measures pressure fields of several MPa with high spatiotemporal resolution, requiring less computational and measurement time. It is used to measure pressure amplitudes from 0.4 to 6.4 MPa, with the potential to extend the range to 0.3-201.6 MPa by adjusting the background-to-target distance. VT-BOS is a promising tool for measuring acoustic pressure in the MHz and MPa ranges, critical for applications such as vessel flow measurement and hydrophone calibration.
  2025年08月, 研究論文（学術雑誌）, 共同, 152, 0041-624X, DOI(公開)(r-map)
• Hydrogel carrier with bubble vibration enhancer for ultrasound-triggered drug release
  Yamakawa, Ryuto; Onoe, Hiroaki; Kurashina, Yuta
  ULTRASONICS SONOCHEMISTRY
  ELSEVIER
  Hydrogel-based drug carriers provide on-demand drug release via external stimuli. Ultrasound is a promising method because of the potential for remotely releasing the drug. However, intense ultrasound irradiation has been required in previous studies. This paper reports drug model release from hydrogel carriers encapsulating bubble vibration enhancers (BVEs) consisting of microbubbles coated with a lipid membrane. Vibration of BVEs induced by ultrasound stimulation promoted the release of drug models with ultrasound irradiation controlled to a biologically safe acoustic pressure based on spatial-peak temporal-average intensity ( I SPTA ). The release ratio increased significantly from 2.3 % without BVEs and ultrasound to 10.2 % with both. To evaluate the frequency response, the release ratio was measured at three different ultrasound frequencies (0.3, 1.8, and 2.5 MHz), showing increased efficiency as the frequency approached the resonance frequency of the BVEs. For in vivo applications, hydrogel microspherical carriers with BVEs achieved a 12 % release ratio. Poly-L-lysine coating successfully suppressed the drug release to 0.2 %. The carriers demonstrated repeated responsiveness when ultrasound was applied in three 5-minute intervals. The hydrogel carrier encapsulating BVEs we proposed is a promising in vivo device capable of releasing drugs on demand by ultrasound irradiation based on its high biosafety and acoustic responsiveness.
  2025年01月, 研究論文（学術雑誌）, 共同, 112, 1350-4177, DOI(公開)(r-map)
• Oil-sealed RGD-modified alginate hydrogel microwell array for analysis of single-cell-derived extracellular vesicles and particles
  Yamagata, Chisaki; Hamazaki, Yuto; Nakazato, Tomoharu; Itai, Shun; Honjo, Mai; Kato, Mami; Kurashina, Yuta; Asai, Makoto; Hoshino, Ayuko; Onoe, Hiroaki
  MICROSYSTEMS & NANOENGINEERING
  SPRINGERNATURE
  We propose an oil-sealed, arginine-glycine-aspartic (RGD) -modified alginate hydrogel microwell array for the analysis of single-cell-derived extracellular vesicles and particles (EVPs) secreted by adherent cells cultured in enclosed spaces. Taking advantage of the mesh structure of alginate hydrogel, we developed a microwell array with size-selective permeability that allows nutrients to pass through the hydrogel while preventing EVPs from doing so. Continuous single-cell culture in sealed microwells (>19 days) has been achieved, while retaining the EVPs inside the microwells. The single-cell-derived EVPs were collected from sealed microwells using a glass capillary to analyze surface membrane proteins. We believe that our oil-sealed RGD-modified alginate hydrogel microwell array will contribute to revealing the heterogeneity of cells, thereby advancing our understanding of the mechanisms of various diseases.
  2025年12月04日, 研究論文（学術雑誌）, 共同, 11, 1, 2055-7434, DOI(公開)(r-map)
• Quantitative assessment of signal quality and usability of EEG and EMG recordings with PEDOT:PSS-coated microneedle electrodes
  Yamaguchi, Tomoya; Kurashina, Yuta; Nagahara, Eiji; Oshima, Sota; Kaneko, Naotsugu; Nakazawa, Kimitaka; Tanaka, Hideyuki; Yokoyama, Hikaru
  FRONTIERS IN NEUROSCIENCE
  FRONTIERS MEDIA SA
  Introduction Bioelectrical signals are vital indicators of physiological function, psychological status, and clinical conditions. However, traditional wet electrodes using conductive gel are time-consuming, labor-intensive, and degrade over time due to gel drying. Recently, microneedle (MN) electrodes coated with poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) have been developed for high-quality signal acquisition. Although low electrode-skin impedance has been demonstrated on hairless regions, their use in electroencephalography (EEG) recordings on hairy scalp areas and quantitative comparisons with conventional electrodes in both EEG and electromyography (EMG) remain limited.Methods We fabricated two MN electrode types of different lengths-one for EMG on hairless skin and one for EEG on the hairy scalp-and compared them with conventional wet and dry electrodes. EMG was recorded during a force-matching task; EEG was assessed via somatosensory evoked potentials. We also evaluated setup/cleanup time, comfort, and pain during EEG measurement.Results For EMG, MN electrodes achieved significantly higher signal-to-noise ratios than conventional electrodes. For EEG, they outperformed dry electrodes and matched wet electrodes in signal quality-without using conductive gel. Although additional time was required to part hair, cleanup was faster due to the absence of gel. Pain was comparable to dry electrodes.Discussion PEDOT:PSS-coated MN electrodes provided superior EMG signal quality and high-quality EEG signals comparable to wet electrodes even without gel. These findings suggest that PEDOT:PSS-coated MN electrodes offer a compelling balance of signal quality and user convenience, making them especially advantageous for real-world and clinical applications where time efficiency, minimal discomfort, and gel-free operation are critical.
  2025年12月03日, 研究論文（学術雑誌）, 共同, 19, DOI(公開)(r-map)

研究発表、招待講演等

• 超音波を用いたナノ薬剤投与システムの開発
  日本音響学会第151回(2024年春季)
  2024年03月07日, 口頭発表（招待・特別）
• Cell Culture and Drug Delivery System Using High-Power Ultrasonic Actuators
  2024 IEEE International Conference on Cyborg and Bionic Systems
  2024年11月20日, 口頭発表（招待・特別）
• Study of drug delivery system using powerful ultrasonic actuators
  The official web site for the 9th International Symposium on Biomedical Engineering
  2024年12月03日, 口頭発表（招待・特別）
• Microsphere-like AAV carrier using hydrogel
  AAV researcher meet up in Kitasato
  2023年11月20日, 口頭発表（招待・特別）
• Heart regeneration with iPS cell-derived cardiomyocytes contributed by using ultrasound and hydrogel
  International Conference on Precision Engineering and Sustainable Manufacturing
  2023年07月19日, 口頭発表（招待・特別）

委員歴

• 日本機械学会学術誌 機械力学・計測制御分野特集号
  アソシエイトエディタ
  自 20240401, 至 20250331
• 日本機械学会 マイクロ・ナノ工学部門
  運営委員
  自 20240401, 至 20250331
• 精密工学会 次世代センサ・アクチュエータ委員
  運営委員
  自 20240401, 至 20250331
• 精密工学会 次世代センサ・アクチュエータ委員会
  運営委員
  自 202304, 至 202403
• 日本機械学会 機械力学・計測制御分野
  若手交流実行委員長
  自 202204, 至 202208
• International Workshop on Piezoelectric Materials and Applications in Actuators
  実行委員
  自 202204, 至 202210

メディア報道

• 【科学技術・大学】慶大など心筋細胞 薬物評価で新技術チューブ内で培養 必要細胞数３ケタ減
  慶応大学と農工大の倉科先生らの研究チームが心筋細胞への薬物評価基盤技術を開発したと紹介される。
  日刊工業新聞
  自 2023年11月17日, 至 2023年11月17日
• 令和7年度 科学技術分野の文部科学大臣表彰
  令和7年度 科学技術分野の文部科学大臣表彰で、科学技術賞の科学技術振興部門「低重力環境下での紛粒体挙動観測による国際宇宙探査への貢献」で農工大 前田孝雄准教授らの研究チームが、若手科学者賞に「超音波によるマイクロナノソフトマテリアル操作の研究」で倉科佑太准教授が受賞したと掲載される。
  科学新聞
  自 2025年04月18日, 至 2025年04月18日

受賞

• 化学とマイクロ・ナノシステム学会
  若手優秀賞
  2025年03月12日
• The 37th IEEE International conference on micro electro mechanical systems (MEMS)
  Outstanding Student Oral Presentation Award Finalist
  2024年01月25日
• PRESM 2023
  Young Researcher Award（International Conference on Precision Enginneering and Sustainable Manufacturing）
  若手研究者として精密工学および持続可能な製造の分野に顕著な貢献をした功績を称え、授与される。
  2023年07月14日
• 文部科学省
  令和7年度科学技術分野の文部科学大臣表彰 若手科学者賞
  「超音波によるマイクロナノソフトマテリアル操作の研究」
  文部科学省では、科学技術に関する研究開発、理解増進等において顕著な成果を収めた者を「科学技術分野の文部科学大臣表彰」として顕彰してきており、そのうち「若手科学者賞」は萌芽的な研究、独創的視点に立った研究等、高度な研究開発能力を示す顕著な研究業績をあげた40歳未満（出産・育児により研究に専念できない期間があった場合は、42歳未満）の若手研究者が対象。
  2025年04月15日
• 化学とマイクロ・ナノシステム学会
  2024年度化学とマイクロ・ナノシステム学会若手優秀賞
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  第16回マイクロ・ナノ工学シンポジウムにおいて新規性に優れ創意工夫に富む研究論文を発表した者に授与される。
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