Heterogeneity and nonaffinity of cell-induced matrix displacements
Heterogeneity and nonaffinity of cell-induced matrix displacements
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DOI：
10.1103/physreve.98.052410
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发表时间：
2018-11-26
影响因子：
2.4
通讯作者：
Notbohm, Jacob
中科院分区：
文献类型：
--
作者：
Burkel, Brian;Proestaki, Maria;Notbohm, Jacob
细胞收缩力使周围的基质变形和重组，但由于纤维结构带来了一系列复杂的力学特性，力和由此产生的位移之间的关系变得复杂。许多研究已经量化了宏观尺度上的非线性和随时间变化的性质，但尚不清楚宏观性质是否适用于细胞尺度，因为细胞的基质是由不同种类的纤维网络组成的。为了解决这个问题，我们模拟了嵌入纤维胶原基质中的细胞的收缩，并量化了由此产生的位移。数据显示，位移是不均匀的和非仿射的。在循环加载过程中，这种非均质性是可重现的，并且随纤维长度的减小而减小。实验和纤维网络模型都表明，非均匀位移随距离的衰减速度不比平均位移场的速度快，这表明没有过渡到均匀的连续介质行为。细胞完全嵌入胶原基质的实验也揭示了异质移位的存在，暴露了由同一纤维基质中不同位置的细胞诱导的基质重组的显著异质性。
Cell contractile forces deform and reorganize the surrounding matrix, but the relationship between the forces and the resulting displacements is complicated by the fact that the fibrous structure brings about a complex set of mechanical properties. Many studies have quantified nonlinear and time-dependent properties at macroscopic scales, but it is unclear whether macroscopic properties apply to the scale of a cell, where the matrix is composed of a heterogeneous network of fibers. To address this question, we mimicked the contraction of a cell embedded within a fibrous collagen matrix and quantified the resulting displacements. The data revealed displacements that were heterogeneous and nonaffine. The heterogeneity was reproducible during cyclic loading, and it decreased with decreasing fiber length. Both the experiments and a fiber network model showed that the heterogeneous displacements decayed over distance at a rate no faster than the average displacement field, indicating no transition to homogeneous continuum behavior. Experiments with cells fully embedded in collagen matrices revealed the presence of heterogeneous displacements as well, exposing the dramatic heterogeneity in matrix reorganization that is induced by cells at different positions within the same fibrous matrix.