微流控通道内细胞及其初级纤毛的力传导行为

细胞处于复杂的生理环境之下,附着在细胞表面的初级纤毛被认为是重要的力学信号传感器,其与细胞的代谢、发育、分裂和增殖等生理活动密切相关.为了研究细胞及其初级纤毛在微流体环境下的力传导行为,本文建立了力-电协同驱动下的矩形微流控通道和含有多孔黏弹性属性的贴壁细胞有限元模型系统.考察了细胞的细胞质和细胞核在振荡层流下的应力、应变、孔隙压力和孔隙流速等力学信号响应,量化研究了初级纤毛作为细胞独特的力学感受器的生物力学行为. 结果表明:细胞在振荡层流下的力学响应表现出和外加力-电驱动载荷相同的震荡规律.渗透率是细胞多孔弹性力学行为的主要影响因素. 初级纤毛是细胞主要的力学感受器,细胞可以通过纤毛长度和直径调节其力学感受敏感性(应力影响区域),随着初级纤毛长度的增大, 其纤毛挠曲刚度减小, 但是敏感性增大.模型的建立为进一步研究微流体剪切作用下的细胞生长、分化等微观机理提供基础,同时也为检测细胞微结构器(纤毛等蛋白链)的力学性能提供了理论技术支持. 

MECHANOTRANSDUCTION OF THE CELL AND ITS PRIMARY CILIUM IN THE MICROFLUIDIC CHANNEL 1)

Cells usually live in a complex physiological environment. The primary cilium, which is a an important organelle of the cell, is attached to the cell surface and is regard as an important mechanical signal sensor to help living cell receive various external mechanical signals, the primary cilium is considered to be closely related to physiological activities such as metabolism, development, division and proliferation of the living cell. In order to study the mechanotransduction behavior of the living cell and the primary cilium growing on its surface in a microfluidic environment, this paper established the adherent cells within a rectangular microfluidic control channel model system, cells with poroviscoelastic properties are in a culture solution driven by the pressure gradient and electric field driven loads. The mechanical signal responses of cytoplasm and nucleus of cells such as the stress, strain, pore fluid pressure and pore fluid velocity under oscillatory laminar flow were investigated, as the mechanical signal's receptors of the living cell, the primary cilium's biomechanical behavior was quantitatively investigated. The results show that the mechanical response of the living cell under an oscillating laminar flow field has the same oscillating law as the synchronous external the pressure gradient and electric field driven loads. The permeability of the living cell is one of the most important physical parameters affecting the cell's poroviscoelastic behavior. Primary cilium is the main mechanoreceptor organelle. The living cell can adjust their mechanical sensitivity (stress-affected zone) by changing the length and diameter of its primary cilium. With the increase of the length of the primary cilium, the flexural rigidity of the primary cilium decreases, but the sensitivity increases. The establishment of the model provides a basis for further research on the microscopic mechanisms of cell growth and differentiation under the loading of microfluidic shear stress, and also provides theoretical technical support for testing the microstructure mechanical properties of the cell anticipates (protein chains such as primary cilium).