Details of a Researcher - Takemura, Kenjiro

Papers - Takemura, Kenjiro

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Enzyme-free release of adhered cells from standard culture dishes using intermittent ultrasonic traveling waves

Yuta Kurashina, Chikahiro Imashiro, Makoto Hirano, Taiki Kuribara, Kiichiro Totani, Kiyoshi Ohnuma, James Friend, Kenjiro Takemura

Communications Biology (Nature Publishing) 2 ( 1 ) 393 2019.10

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted, ISSN 2399-3642

Cell detachment is essential in culturing adherent cells. Trypsinization is the most popular detachment technique, even though it reduces viability due to the damage to the membrane and extracellular matrix. Avoiding such damage would improve cell culture efficiency. Here we propose an enzyme-free cell detachment method that employs the acoustic pressure, sloshing in serum-free medium from intermittent traveling wave. This method detaches 96.2% of the cells, and increases its transfer yield to 130% of conventional methods for 48 h, compared to the number of cells detached by trypsinization. We show the elimination of trypsinization reduces cell damage, improving the survival of the detached cells. Acoustic pressure applied to the cells and media sloshing from the intermittent traveling wave were identified as the most important factors leading to cell detachment. This proposed method will improve biopharmaceutical production by expediting the amplification of tissue-cultured cells through a more efficient transfer process.

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Method of localized removal of cells using a bolt‐clamped Langevin transducer with an ultrasonic horn

T Inui, Y Kurashina, C Imashiro, K Takemura

Engineering in Life Sciences (Wiley) 19 ( 8 ) 575 - 583 2019.08

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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Mechanism of cellular detachment caused by frequency sweep vibration

KURASHINA Yuta, IMASHIRO Chikahiro, TAKEMURA Kenjiro

The Proceedings of the Dynamics & Design Conference (The Japan Society of Mechanical Engineers) 2019 426 2019.08

Research paper (other academic), Joint Work, Last author

Nowadays, innovative therapies for tissue engineering and regenerative medicine have been created and a large number of cells with high viability are cultured for these therapies. In the cell detachment method with common protein-degrading enzymes, the cell membranes are damaged at the detachment. On the other hand, the cell detachment method with ultrasonic vibration can detach without damage of cell membranes. For instance, the adherent cells on the culture dish are detached from the bottom of the dish by using sweep vibration without enzymes. The deformation of the culture dish, the acoustic streaming-driven shear flow, the acoustic pressure on a boundary of different materials having different acoustic impedance, and the sloshing of the liquid are candidates for detachment factor. However, details of the dominant conditions for cell detachment are not obvious. Therefore, in this study, we evaluated the effects of each factor on cell detachment from experiments and theory. As results, the deformation of the culture dish or the acoustic streaming-driven shear flow does not have sufficient force to detach the cells, while the pressure between the different acoustic impedance and the sloshing of the liquid are sufficient to detach the cells from reference. That is, these results indicate that the different acoustic impedance and the sloshing of the liquid are dominant factors for cell detachment with ultrasonic vibration.

Effective and Intact Cell Detachment from a Clinically Ubiquitous Culture Flask by Combining Ultrasonic Wave Exposure and Diluted Trypsin

H Tauchi, C Imashiro, T Kuribara, G Fujii, Y Kurashina, K Totani, ...

Biotechnology and Bioprocess Engineering (Springer) 24 ( 3 ) 536 - 543 2019.06

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted, ISSN 12268372

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シートベルトウェビングの触感の定量化

小山和人, 小ヶ口晃, 嶋崎定幸, 中山正大, 寺井宏樹, 竹村研治郎

第58回日本生体医工学会大会予稿集 (Japanese Society for Medical and Biological Engineering) 57 jsmbe58001-00190 2019.06

Research paper (other academic), Joint Work, Last author, Corresponding author, ISSN 1347-443X

シートベルトウェビング（ベルト部分）は乗車に際して必ず触れるものであり，製品開発において触感の向上が重要な課題のひとつである．シートベルトウェビングの触感向上に関する先行研究の多くは触感を説明する要因として物性値を測定しているが，ヒトが触覚受容器の応答によって触感を知覚することに鑑みると，物性値のみでは必ずしもシートベルトウェビングの触感を言い表せるとは言えない．このため，本研究では物性値だけでなくシートベルトウェビングを触察した際の振動情報も用いて触感を定量化した．被験者に7種類のサンプルをSD法により評価させ，その結果から主成分分析を用いてシートベルトウェビングの触感に関する主成分を求めた．この結果，低次触感では「粗滑感」「硬軟感」「湿感」，高次触感では「高級感」の主成分が抽出された．つぎに，サンプルの物性値および触察時の振動情報を測定し，重回帰分析を用いて，物性値および振動情報と触感に関する主成分の関係を定式化した．この結果，物性値および振動情報から触感を予測する線形モデルを構築した．

内部閉流路の選択的加圧による多自由度ソフトロボットフィンガ

尾﨑晃洋, 新間良平, 竹村研治郎

第58回日本生体医工学会大会 (Japanese Society for Medical and Biological Engineering) 57 ( 0 ) jsmbe58001-00143 2019.06

Research paper (other academic), Joint Work, Last author, Corresponding author, ISSN 1347-443X

近年，柔軟軽量なソフトロボットに関する研究が広く行われており，ロボットハンドもその対象として注目されている．ロボットハンドが様々な形状の物体を把持するには多様な把持姿勢の実現が求められる．すなわち，ロボットハンドを構成するロボットフィンガには，屈曲伸展運動に加えて内転外転運動が必要になる．このため，本研究では，屈曲伸展運動および内転外転運動が可能なソフトロボットフィンガを具現化する．開発したソフトロボットフィンガはアラミド繊維で繊維強化されたシリコーンゴム製のチューブで構成される．チューブ内部には半円筒状の閉流路が2本設けられており，それぞれ独立して内部を加圧できる．閉流路を加圧するとチューブは膨張するが，周方向および手掌側に配置された繊維によって，その膨張は一部拘束される．結果，双方の閉流路を加圧するとフィンガは屈曲し，一方の閉流路を加圧するとフィンガは内転する．本フィンガは，直径7.0 mm，全長60 mm，質量0.70 gであり，上記閉流路を最大14 kPaで加圧した際の最大屈曲角度および内転角度はそれぞれ79°および34°であった．

低濃度のトリプシンと超音波照射による汎用フラスコからの細胞剥離

今城哉裕, 田内葉奈子, 栗原大輝, 倉科佑太, 戸谷希一郎, 竹村研治郎

第58回日本生体医工学会大会 (Japanese Society for Medical and Biological Engineering) 57 ( 0 ) 2-PM-PO-B5 PO-B-110 2019.06

Research paper (other academic), Joint Work, Last author, Corresponding author, ISSN 1347-443X

近年，細胞の医療応用に注目が集まっている．これに伴って効率的な細胞培養法が研究されており，とくに細胞剥離に関する研究が盛んである．一般的にはトリプシンに浸漬した細胞に対してピペッティング等の機械刺激を付与することで細胞を剥離する．トリプシンの毒性を鑑みると，低濃度のトリプシンを用いることが望ましいが，細胞の剥離率が低下してしまう．そこで，本研究では，超音波の併用よって低濃度のトリプシンによる細胞剥離を実現した．汎用フラスコに接着した接着細胞の下方から超音波を付与する装置（図）を開発した．さらに，バースト波を用いた超音波照射によって温度上昇を抑制しつつ，高強度の超音波を細胞に付与した．この結果，ピペッティングでは一部の細胞のみが剥離する低濃度トリプシンを用いた際にも，超音波の照射によって全細胞が剥離した．低濃度トリプシンで細胞剥離を実現したことで細胞の増殖性が向上したこと，超音波照射によるタンパク質発現の変化や代謝に異常がないことを確認した．

Formation of Large Scaffold-Free 3-D Aggregates in a Cell Culture Dish by Ultrasound Standing Wave Trapping

Nakao Misa, Imashiro Chikahiro, Kuribara Taiki, Kurashina Yuta, Totani Kiichiro, Takemura Kenjiro

Ultrasound in medicine and biology (Elsevier) 45 ( 5 ) 1306 - 1315 2019.05

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted, ISSN 0301-5629

Cellular aggregates that mimic cell–cell interactions in vitro are essential for biological research. This study introduces a method to form large scaffold-free 3-D aggregates in a clinically ubiquitous cell culture dish using kilohertz-order ultrasound standing wave trapping (USWT). We fabricated an aggregate formation system in which a 60-mm dish was set above a Langevin transducer via water. The transducer was excited at 110.8 kHz, and then C2C12 myoblasts were injected into the dish and trapped at the node position of the standing wave. The diameter and thickness of the formed aggregate were 8 and 2.7 mm, respectively, which are larger than those of aggregates formed previously by USWT. Moreover, we confirmed that >94% of cells constituting the aggregates survived 9 h, and the protein expression of cells was not altered significantly. This method can be applied to form aggregates with high functionality, which contributes to the development of biological research methodology.

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Ultrasonic motor with embedded preload mechanism

T Kazumi, Y Kurashina, K Takemura

Sensors and Actuators A: Physical (Elsevier) 289 44 - 49 2019.04

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted, ISSN 09244247

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Growth control of leaf lettuce with exposure to underwater ultrasound and dissolved oxygen supersaturation

Yuta Kurashina, Tatsuya Yamashita, Shuichi Kurabayashi, Kenjiro Takemura, Keita Ando

Ultrasonics - Sonochemistry (ELSEVIER) 51 292 - 297 2019.03

Research paper (scientific journal), Joint Work, Accepted, ISSN 13504177

The growth rate of vegetables in plant factories can be regulated by environmental factors including light, temperature, and chemicals, which might give rise to mutation in leaf health. Here, we aim to devise a new way that allows for controlling the growth rate of plants in hydroponics as well as maintaining the product quality; we apply underwater ultrasound and dissolved oxygen supersaturation as external stimuli to plants. As an example, we examine the growth of leaf lettuce in hydroponics with exposure to 28-kHz ultrasound and dissolved oxygen supersaturation up to 36 mg/L at 20 °C. Our results show that exposure to the ultrasound of peak-to-peak pressure at 20 kPa or larger works as the growth inhibitor of the leaves and the roots, while the oxygen supersaturation as the growth promoter, without any degradation of chlorophyll in the leaves. This suggests that these external stimuli can be used in the growth control system of plant factories.

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ECF (electro-conjugate fluid) finger with bidirectional motion and its application to a flexible hand

T Nagaoka, Z Mao, K Takemura, S Yokota, JW Kim

Smart Materials and Structures ( IOP) 28 ( 2 ) 025032 2019.01

Research paper (scientific journal), Joint Work, Accepted, ISSN 0964-1726

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Cell patterning method on a clinically ubiquitous culture dish using acoustic pressure generated from resonance vibration of a disk-shaped ultrasonic transducer

C Imashiro, Y Kurashina, T Kuribara, M Hirano, K Totani, K Takemura

IEEE Transactions on Biomedical Engineering (IEEE) 66 ( 1 ) 111 - 118 2019.01

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted, ISSN 00189294

Cell patterning methods have been previously reported for cell culture. However, these methods use inclusions or devices that are not used in general cell culture and that might affect cell functionality. Here, we report a cell patterning method that can be conducted on a general cell culture dish without any inclusions by employing a resonance vibration of a disk-shaped ultrasonic transducer located under the dish. A resonance vibration with a single nodal circle patterned C2C12 myoblasts into a circular shape on the dish with 10-min exposure of the vibration with maximum peak-peak amplitude of 10 μm${}-{\text{p-p}}$. Furthermore, the relationship between the amplitude distribution of the transducer and the cell density in the patterned sample could be expressed as a linear function, and there was a clear threshold of amplitude for cell adhesion. To evaluate the cell function of the patterned cells, we conducted proliferation and protein assays at 120-h culture after patterning. Our results showed that the cell proliferation rate did not decrease and the expression of cellular proteins was unchanged. Thus, we conclude, this method can successfully pattern cells

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Difference of Tactile Perception Models by Individuals and Dominant Factor of Fabric Hand for Knitted Fabric for Underwear

Iza Husna MOHAMAD HASHIM, Sumi NANAKAMURA, Kenjiro TAKEMURA

Journal of Textile Engineering (The Textile Machinery Society of Japan) 65 ( 1 ) 1 - 10 2019.01

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted, ISSN 13468235

In the textile industry, fabric hand is one of the crucial aspects that influence the value of fabric. However, the judgement of fabric hand may vary across subjects. Thus, this study proposes to group the subjects based on their evaluation of fabric hand, and the tactile sensations that are dominantly related to fabric hand are investigated. First, a sensory evaluation of eight knitted fabric samples was carried out using 14 verbal expressions of tactile sensation. These 14 verbal expressions were hierarchically classified into three stages which were called as low-order of tactile sensation, high-order of tactile sensation and lastly, fabric hand. After grouping the subjects by using cluster analysis, a principal component analysis was conducted in each stage of tactile sensation to gather the strong correlations of the verbal expressions. Then, the correlations between principal components of each stage were determined by multiple regression analysis. As a result, the study showed that the subjects could be mainly grouped into two. The former group expressed fabric hand as good when the fabric is soft and moist. On the other hand, the latter group defined good fabric hand when the fabric is silky and smooth.

Biotechnology and informotion-ultrasonic actuation technology for cell culture process

Y Kurashina, K Takemura

Journal of Japanese Society of Tribologists (Japanese Society of Tribologists) 63 ( 9 ) 599 - 604 2018.09

Research paper (other academic), Joint Work, Last author, Corresponding author, ISSN 09151168

Making cell culture process automated and efficient is one of the biggest challenges for cell therapy including regenerative medicine, drug screening and body-on-chip drug development. Cell culture process with cell seeding, culturing, detaching and collecting processes is in general conducted manually by a technician. To establish an efficient and stable mass culture process of cells, "informotion technology" may play an important role. By automating cell culture process with actuator/sensor technology and networking them online, know-hows to deal with living cells can be shared. By doing so, we may efficiently provide large number of cells, ready for accelerating regenerative medicine spread. Ultrasonic actuation technology has proved its potentials to be used for cell culture automation.

A Cell Aggregation Method using Acoustic Radiation Pressure and Ekman Transport:(Manipulation of cells using ultrasound and flow)

FUKUMA Yuki, TERAO Yusuke, KURASHINA Yuta, TAKEMURA Kenjiro

The Proceedings of the Dynamics & Design Conference (The Japan Society of Mechanical Engineers) 2018 538 2018.08

Research paper (other academic), Joint Work, Last author, Corresponding author

When co-culturing cells outside the body, it is necessary to culture in an environment closer to the living body. In this study, we tried to manufacture a culture vessel and generate three-dimensional tissue of cells by acoustic radiation pressure and Ekman transport. As a result of experiments with particles simulating cells, the particles remained outside the culture surface in the case of only using acoustic radiation pressure. However, by combining Ekman transport and acoustic radiation pressure, particles could be aggregated efficiently. Therefore, three-dimensional tissue of cells can be generated using these techniques.

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Global Regionality of Tactile Perception for Door Armrests

Wada Toshiyuki, Mori Yukio, Mohamad Hashim Iza Husna, Maeno Takashi, Takemua Kenjiro

Transactions of Society of Automotive Engineers of Japan (Society of Automotive Engineers of Japan) 49 ( 4 ) 764 - 771 2018.07

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted, ISSN 0287-8321

Automobile interior is one of the most crucial factors for evaluating products' value. During the evaluation, tactile cue must play an important role in deducing product's quality, however, the regionality of customer's tactile perception is in most cases neglected in previous studies. This study conducted sensory evaluation tests of door armrests in three countries, Japan, USA and Denmark, which are representatives of East Asia, North America and Europe, respectively. Eight samples of door armrests and 29 words expressing tactile sensations were used in the test. 167 participants in total participated in the evaluation test, 53 from Japan, 64 from USA and 50 from Denmark. As results of factor analysis, cluster analysis and multiple regression analysis, the following conclusion can be derived, i.e., although there is no significant difference in preference perception of door armrests, the tactile perception structures are different among three countries.

Selective Cell Elimination Mediated by Ultrasonic Irradiation

Takumi Inui, Yuta Kurashina, Chikahiro Imashiro, Kenjiro Takemura

The 40th International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE) 2018.07

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Efficient electrode configuration for electro-conjugate fluid flow generation with dibutyl decanedioate: Experimental and theoretical investigation

Y.Kuroboshi, K.Takemura, K.Edamura

Sensors and Actuators, A: Physical (ELSEVIER) 279 223 - 228 2018.06

Research paper (scientific journal), Joint Work, Corresponding author, Accepted, ISSN 09244247

Electro-conjugate fluid (ECF) is a functional fluid that can generate a high-power flow induced by a high direct-current voltage. While ECF has been used in various fields, including mechanical, chemical, and biomedical systems, its underlying principles have not been sufficiently understood to be applicable to ECF system design, and the lack of theoretical models hampers further applications of ECF. This study aims to investigate underlying principles of ECF flow generation with a rectangular-slit electrode pair. By analyzing the effect of electrode configuration on the flow generation, this paper proposes a theoretical model for electrode design for efficient flow generation. The proposed model has been validated by comparing the simulation results with the visualized characteristics from flow experiments. The results show that the flow rate can be controlled by changing the electrode configuration with the maximum flow rate with the rectangular-slit electrode gap of 1.0 mm and the slit electrode gap of 5.0 mm.

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The Influence of Touch Speed on Roughness Perception

Takahiko Nakamura, Masahiro Saito, Kenjiro Takemura

EUROHAPTICS2018 2018.06

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Development of Deep Neural Network Models to Mimic Human-Like Classification of Genuine/synthetic Leathers

Masahiro Saito, Shinsuk Park, Kenjiro Takemura

EUROHAPTICS2018 2018.06

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

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