Multiscale simulation of erythrocyte membranes.
Multiscale simulation of erythrocyte membranes.
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DOI：
10.1103/physreve.81.031904
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发表时间：
2010-03
期刊：
影响因子：
--
通讯作者：
Zhu Q
中科院分区：
文献类型：
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作者：
Peng Z;Asaro RJ;Zhu Q
为了定量预测红细胞的机械响应和机械诱导的重塑，我们开发了一种多尺度方法，将内应力的分布与整体细胞变形相关联。该方法包括三个不同长度尺度的模型：在完整的单元层次上，用有限元方法将膜模拟为两层不同的连续壳（III级），其中双分子-双层相互作用被描绘为横向图中的幻灯片。（即面内）方向（由双分子层钉扎点的移动性引起）和法向接触力;内层本构关系（蛋白质骨架）是从分子模型中获得的（二级）;血影蛋白的力学性质（SP，骨架的关键组成部分），包括其折叠/展开反应，得到的应力-应变模型（I级）。模型验证是通过与现有的数值和实验研究的细胞的静止形状以及细胞变形引起的微量移液器和光镊方面的比较。详细的分布之间的相互作用力的脂质双层和骨架，可能会导致他们的解离，并导致的现象，如囊泡的预测。具体而言，我们的模型预测SP展开的发生和增加的机械负荷后，个人的双分子层钉扎点之间的相关性。最后，颈缩过程的模拟后，双分子层解离，囊泡化的前体，进行。
To quantitatively predict the mechanical response and mechanically induced remodeling of red blood cells, we developed a multiscale method to correlate distributions of internal stress with overall cell deformation. This method consists of three models at different length scales: in the complete cell level the membrane is modeled as two distinct layers of continuum shells using finite element method (Level III), in which the skeleton-bilayer interactions are depicted as a slide in the lateral (i.e. in-plane) direction (caused by the mobility of the skeleton-bilayer pinning points) and a normal contact force; the constitutive laws of the inner layer (the protein skeleton) are obtained from a molecular-based model (Level II); the mechanical properties of the spectrin (Sp, a key component of the skeleton), including its folding/unfolding reactions, are obtained with a stress-strain model (Level I). Model verification is achieved through comparisons with existing numerical and experimental studies in terms of the resting shape of the cell as well as cell deformations induced by micropipettes and optical tweezers. Detailed distributions of the interaction force between the lipid bilayer and the skeleton that may cause their dissociation and lead to phenomena such as vesiculation are predicted. Specifically, our model predicts correlation between the occurrence of Sp unfolding and increase in the mechanical load upon individual skeleton-bilayer pinning points. Finally a simulation of the necking process after skeleton-bilayer dissociation, a precursor of vesiculation, is conducted.