梯度流体剪应力下细胞膜张力的数值模拟

Numerical Simulation of Cell Membrane Tension under Gradient Fluid Shear Stress

目的分析梯度流体剪应力(fluid shear stress,FSS)流场中细胞膜张力分布。方法构建梯度平板流动腔模型,采用流固耦合数值模拟方法,研究不同FSS梯度和幅值、不同静水压下细胞膜的膜张力分布。结果当流动腔入口流量增大时,FSS流场梯度呈正比例增大。梯度FSS流场下,细胞膜张力由贴壁侧向顶部呈先减小后增大的趋势。在正常人体血压下,静水压越大,细胞膜张力越大。当FSS幅值一定时,增加FSS梯度,细胞高、低FSS区域平均膜张力差值增大;当FSS梯度一定时,增加FSS幅值,细胞高、低FSS区域平均膜张力差值增大。结论梯度FSS流场会引起细胞膜张力的局部差异,其可能是破骨前体细胞在梯度流场中定向迁移的重要原因。

Objective To investigate the distribution of cell membrane tension in a gradient fluid shear stress(FSS)field.Methods A gradient plate flow chamber model was constructed.Fluid-solid coupling numerical simulations were conducted to analyze the distribution of membrane tension with different FSS gradients and FSS amplitudes under varying hydrostatic pressures.Results With an increase in the flow rate at the inlet of the flow chamber,the FSS gradient exhibited a proportionally positive increase.Under the gradient FSS field,the cell membrane tension initially decreased and then increased from the bottom to the top of the cell.Under normal blood pressure,higher hydrostatic pressure was correlated with increased membrane tension.Larger FSS amplitudes result ed in higher membrane tension.When the FSS amplitude was constant,the average difference in membrane tension between the high-and low-FSS regions increased with the FSS gradient.Similarly,with a constant FSS gradient,the average difference in membrane tension between the high-and low-FSS regions increased with the FSS amplitude.Conclusions Local variation in cell membrane tension induced by gradient FSS is a crucial factor influencing the directional migration of osteoclast precursors in a gradient FSS field.