Structural Hierarchy Governs Fibrin Gel Mechanics
Structural Hierarchy Governs Fibrin Gel Mechanics
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DOI：
10.1016/j.bpj.2010.01.040
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发表时间：
2010-05-19
影响因子：
3.4
通讯作者：
Koenderink, Gijsje H.
中科院分区：
文献类型：
--
作者：
Piechocka, Izabela K.;Bacabac, Rommel G.;Koenderink, Gijsje H.
纤维蛋白凝胶负责血凝块的机械强度，血凝块是自然界中最具弹性的蛋白质材料之一。在这里，我们通过对重构的纤维蛋白凝胶进行流变学测量来研究这种机械行为的物理起源。我们发现，剪切应变水平的增加会引起一系列不同的弹性响应，反映不同长度尺度上的拉伸过程。我们提出了一个理论模型，根据纤维独特的层次结构解释了这些观察结果。纤维是半柔性原纤维束，通过柔性连接链松散地连接。这种结构使光纤的弯曲柔韧性比基于其大直径的预期高出 100 倍。此外，与其他生物聚合物相比，纤维蛋白纤维在拉伸时本质上会变硬。由此产生的弹性体系层次解释了纤维蛋白凝块对大变形的令人难以置信的弹性。
Fibrin gels are responsible for the mechanical strength of blood clots, which are among the most resilient protein materials in nature. Here we investigate the physical origin of this mechanical behavior by performing rheology measurements on reconstituted fibrin gels. We find that increasing levels of shear strain induce a succession of distinct elastic responses that reflect stretching processes on different length scales. We present a theoretical model that explains these observations in terms of the unique hierarchical architecture of the fibers. The fibers are bundles of semiflexible protofibrils that are loosely connected by flexible linker chains. This architecture makes the fibers 100-fold more flexible to bending than anticipated based on their large diameter. Moreover, in contrast with other biopolymers, fibrin fibers intrinsically stiffen when stretched. The resulting hierarchy of elastic regimes explains the incredible resilience of fibrin clots against large deformations.