Stiffening of Individual Fibrin Fibers Equitably Distributes Strain and Strengthens Networks
Stiffening of Individual Fibrin Fibers Equitably Distributes Strain and Strengthens Networks
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DOI：
10.1016/j.bpj.2009.12.4312
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发表时间：
2010-04-21
影响因子：
3.4
通讯作者：
Falvo, Michael R.
中科院分区：
文献类型：
--
作者：
Hudson, Nathan E.;Houser, John R.;Falvo, Michael R.
作为血凝块的结构骨架，纤维蛋白网络执行在血管损伤部位阻塞血流的机械任务。这些网络表现出丰富的一套显着的机械性能，但详细的图片有关的微观力学的个别纤维的整体网络性能尚未完全开发。特别是，单根纤维的高应变和失效特性如何影响网络的整体强度尚不清楚。使用组合的荧光/原子力显微镜纳米操纵系统，我们将2-D纤维蛋白网络拉伸到失效点，同时记录单个纤维的应变。我们的研究结果进行了比较，一对模型网络：一个组成的线性响应元件和第二个非线性，应变硬化元素。我们发现，个别纤维的应变硬化是必要的，以解释我们在实验中观察到的整个网络的应变传播模式。纤维应变硬化的作用是在网络内更公平地分布应变，减少应变最大值，并增加网络强度。沿着其生理意义，详细了解这种强化机制可能会导致工程聚合物材料的新设计策略。
As the structural backbone of blood clots, fibrin networks carry out the mechanical task of stemming blood flow at sites of vascular injury. These networks exhibit a rich set of remarkable mechanical properties, but a detailed picture relating the microscopic mechanics of the individual fibers to the overall network properties has not been fully developed. In particular, how the high strain and failure characteristics of single fibers affect the overall strength of the network is not known. Using a combined fluorescence/atomic force microscope nanomanipulation system, we stretched 2-D fibrin networks to the point of failure, while recording the strain of individual fibers. Our results were compared to a pair of model networks: one composed of linearly responding elements and a second of nonlinear, strain-stiffening elements. We find that strain-stiffening of the individual fibers is necessary to explain the pattern of strain propagation throughout the network that we observe in our experiments. Fiber strain-stiffening acts to distribute strain more equitably within the network, reduce strain maxima, and increase network strength. Along with its physiological implications, a detailed understanding of this strengthening mechanism may lead to new design strategies for engineered polymeric materials.