General solutions of linear poro-viscoelastic materials in spherical coordinates
General solutions of linear poro-viscoelastic materials in spherical coordinates
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DOI：
10.1017/jfm.2022.552
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发表时间：
2022-08
影响因子：
3.7
通讯作者：
M. Moradi;Wenzheng Shi;E. Nazockdast
中科院分区：
文献类型：
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作者：
M. Moradi;Wenzheng Shi;E. Nazockdast
摘要细胞骨架是由半柔性微丝和运动蛋白动态组装而成。细胞骨架力学在细胞分裂、运动和迁移、机械传递和细胞内运输等过程中起着决定性的作用。细胞的机械性质部分由其细胞骨架决定，也被用作疾病诊断和细胞分选的生物标志物。实验研究表明，在全细胞尺度下，细胞骨架及其渗透的胞质溶胶可以模拟为两相多孔粘弹性（PVE）材料，该材料由粘性胞质溶胶渗透的粘弹性（VE）网络组成。我们提出了第一个一般的解决方案，这个两相系统在球坐标系中，我们假设流体和网络相都在其线性响应制度。具体来说，我们使用广义线性不可压缩和可压缩VE本构方程来描述在流体和网络相的应力，分别。我们假设一个恒定的渗透率耦合流体和网络的位移。我们使用这些一般的解决方案来研究运动的刚性球在一个恒定的力在两相系统，由一个线性弹性网络和牛顿流体。结果表明，网络的可压缩性引入了一个缓慢松弛的球和非单调的网络位移随时间沿着方向的作用力。我们的研究结果可以应用于颗粒跟踪微观流变学，以区分PVE和VE材料，并测量流体渗透率以及流体和网络相的VE特性。
Abstract The cell cytoskeleton is a dynamic assembly of semi-flexible filaments and motor proteins. The cytoskeleton mechanics is a determining factor in many cellular processes, including cell division, cell motility and migration, mechanotransduction and intracellular transport. Mechanical properties of the cell, which are determined partly by its cytoskeleton, are also used as biomarkers for disease diagnosis and cell sorting. Experimental studies suggest that in whole cell scale, the cell cytoskeleton and its permeating cytosol may be modelled as a two-phase poro-viscoelastic (PVE) material composed of a viscoelastic (VE) network permeated by a viscous cytosol. We present the first general solution to this two-phase system in spherical coordinates, where we assume that both the fluid and network phases are in their linear response regime. Specifically, we use generalized linear incompressible and compressible VE constitutive equations to describe the stress in the fluid and network phases, respectively. We assume a constant permeability that couples the fluid and network displacements. We use these general solutions to study the motion of a rigid sphere moving under a constant force inside a two-phase system, composed of a linear elastic network and a Newtonian fluid. It is shown that the network compressibility introduces a slow relaxation of the sphere and non-monotonic network displacements with time along the direction of the applied force. Our results can be applied to particle-tracking microrheology to differentiate between PVE and VE materials, and to measure the fluid permeability as well as VE properties of the fluid and the network phases.