A biological cell migrates on the scaffold. In several cases, cells are exposed to the shear stress both in vivo and in vitro. The direction of the shear stress field might affect the direction of the migration. The hysteresis also might affect the direction of the migration. The behavior of each cell might depend on the initial state. In the most of tests in vitro, cells are incubated for several hours for adhesion to the scaffold before flow stimulation. Each cell can make division under the wall shear stress field. Is the effect maintained in each cell after division? The adhesion status of the cell is controlled by itself after division. In the present study, the migration of each cell is tracked at the division in the shear stress field of the medium.The effect of the shear flow on the endothelial cells, which are exposed to the blood flow on the inner surface of the vessel wall, were investigated in many studies. In the previous study with the vortex flow by the swinging plate in vitro, C2C12 (mouse myoblast cell line originated with cross-striated muscle of C3H mouse) made orientation perpendicular to the direction of the flow, although HUVEC (Human Umbilical Vein Endothelial Cells) made orientation along the streamline of the flow. The orientation of each cell in the tissue depends on that of adjacent cell.At the wall shear stress, a cell might show the following responses: elongation, tilting to the streamline, migration, deformation to be rounded, proliferation, and exfoliation from the wall of the scaffold. In the Poiseuille type of flow, the shear rate depends on the distance from the wall: highest at the wall. In the Couette type of flow, on the other hand, the shear rate is constant regardless of the distance from the wall.In the present study, an experimental system of the Couette type flow in the constant gap with a rotating disk has been designed to apply the shear stress quantitatively on the cell during incubation at the microscopic observation in vitro, and the effect of the shear stress field (1 Pa) on each cell at division has been studied about migration.The experimental results show the following behavior of each cell type. The deformation of HUVEC is larger than that of the other cell type. The shape index decreases much before division, and increases much after division. The deformation of C2C12 is smaller than that of the other cell type. After division, C2C12 tends to return to the same direction as that of before division under the shear stress field of 1 Pa. After division, 3T3-L1 (mouse fat precursor cells, a cell line derived from cells of mouse 3T3) tends to change the deformation direction different from that of before division under the shear stress field of 1 Pa.

Cell Activity Change After Division Under Wall Shear Stress Field

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

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