著者

日野 遥 杉本 大己 高橋 優輔 橋本 成広

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.858, pp.17-00202-17-00202, 2018 (Released:2018-02-25)

参考文献数

16

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Mechanical stimulation affects cell behaviors (proliferation, orientation, migration and differentiation) in vivo, and a lot of models of experiments on mechanical stimulation in vitro have been reported. The development of control technique on cell is important in the field of regenerative medicine. Recently, skeletal myoblasts have been applied for cardiac repair. In the previous study, C2C12 (mouse myoblast cell line) made orientation perpendicular to the streamlines in the donut shape flow channel. In the present study, C2C12 has been cultured in the Couette type of the shear field between the rotating disk and the stationary culture plate to study quantitatively the effect of shear stress (for 24 hours, < 2 Pa) on orientation of myoblasts in vitro. The time lapse image of myoblasts shows that C2C12 tilts perpendicularly against the flow direction at the wall shear stress of 2 Pa and that C2C12 tends to migrate to the lower wall shear stress region of 0.4 Pa.

著者

日野 遥 田村 卓也 杉本 大己 高橋 優輔 橋本 成広

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.858, pp.17-00368-17-00368, 2018 (Released:2018-02-25)

参考文献数

9

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It is already known that micro gravity affects astronaut’s body. In contrary, hyper-gravity might affect myoblasts. In the present study, mouse muscle cells (C2C12) were cultured four five hours in hyper-gravitational environment (50 G, 100 G) using the centrifugal machine placed in the incubator. Cells were observed at the incubator microscope for 24 hours after stopping centrifugation. The contour of each cell at the time-lapse images was approximated to the ellipsoid and several parameters were calculated: the angle, the area, and the aspect ratio. Each cell tends to shrink from the extended shape under hyper-gravitational environment. The directions of the major axis at 50% of cells tilt to the parallel direction to the hypergravity. After 24 hours, 51% of cells tilt to the perpendicular direction of the hypergravity in the 50 G group. The result shows that the history of hyper-gravitational environment affects the shape of cells.

著者

日野 遥 杉本 大己 篠崎 祐輔 高橋 優輔 橋本 成広

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.858, pp.17-00166-17-00166, 2018 (Released:2018-02-25)

参考文献数

18

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A parallel-piped flow channel with micro-striped patterns has been designed to study the effect of the shear field on the myoblast in vitro. The micro-pattern was manufactured with the photolithography technique and used for the scaffold of the cell culture in the flow chamber placed in the incubator on the microscope. Variation was made on the angle between the stripe of the pattern and the flow direction: 0, 45, and 90 degrees. After cultivation for 4 hours, C2C12 (mouse myoblast cell line) adhered on the micro-pattern was exposed to the shear flow for 4 hours. The wall shear stress is estimated from the parabolic velocity profile in the medium between the parallel walls. With the experimental system, the following tendencies of responses (deformation, orientation, and migration) of each cell was observed. Under the wall shear stress of < 3 Pa, each cell deforms to the round shape at first, and extends again along the stripe-pattern. Orientation of each cell is collapsed during exposure to the wall shear stress of 3 Pa, and is recovered after stopping exposure to the shear field. The results show that the experimental system is available to investigate quantitatively the effect of mechanical stress field on the oriented cell.

著者

高橋 優輔 杉本 健太 日野 遥 橋本 成広

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.854, pp.17-00178-17-00178, 2017 (Released:2017-10-25)

参考文献数

10

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Control technique of orientation of a biological cell is expected to be applied to tissue engineering. It is known that morphology of the scaffold affects the cell behavior. For example, the micro stripe pattern can control cell orientation. The effect of aspect ratio of the micro checkered pattern on cell orientation has been investigated in the present study. The dimension of each unit of the micro checkered pattern is as follows: the length is 10 μm, and the height is 0.7 μm. Variation has been made on the width of the micro pattern: 5 μm (A), 8 μm (B) and 10 μm (C). Each type of repeated micro pattern was formed in the square area of 500 μm × 500 μm. The micro pattern was made of the negative photoresist material (SU-8 2) coated on a glass plate by the photolithography technique. C2C12 (mouse myoblast cell) was cultured for 24 hours on the micro pattern. The angle between the longitudinal axis of each cell and the width of the micro pattern was measured on the microscopic image. In each pattern, the average angle was as follows: 62.8 degrees on A, 50.2 degrees on B and 41.2 degrees on C. The experimental results show that the aspect ratio of micro checkered pattern controls cell orientation.

著者

高橋 優輔 吾妻 樹 溝井 篤志 日野 遥 橋本 成広

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.854, pp.16-00110-16-00110, 2017 (Released:2017-10-25)

参考文献数

19

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Separation technique of the circulating tumor cell (CTC), which would be a sample for diagnostics of cancer, is important. In the present study, a micro flow device, which has gaps between micro-cylinders, has been fabricated by photolithography technique to distinguish between cancer cells and red blood cells. Two kinds of cells were used in the test: Hepa1-6 and swine red blood cell. The mean diameters of two kinds of cells measured by ImageJ were 21 μm and 6 μm. Variation was made on the dimension of the gap: 10, 15, 20 and 25 μm. The micro cylindrical pattern was fabricated on the slide glass with a photomask of titanium film. The negative resist material (SU-8) was coated on the glass plate to make the 60 μm height of the micro cylindrical pattern. A micro flow channel was made between the glass plate with the micro cylindrical pattern and the flat polydimethylsiloxane (PDMS) disk. Swine blood was diluted 100 times by the saline solution. The concentration of Hepa1-6 was adjusted to 5000 cells/ml by the physiological saline solution or by the swine blood. The cell suspension of 30 μl was injected into the channel by a micropipette, and the trap rate at the gap of the micro pattern was measured. The experimental result shows that trap rates of micro cylindrical pattern gap of 10, 15, 20 and 25 μm are 100, 80, 37 and 26%, respectively. Most of the swine red blood cells can pass through the 10 μm gap. The result shows that the microchannel device developed in the present study is effective for the separation of the CTC.