The elasticity of an individual fibrin fiber in a clot
The elasticity of an individual fibrin fiber in a clot
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DOI：
10.1073/pnas.0504120102
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发表时间：
2005-06-28
影响因子：
11.1
通讯作者：
Weisel, JW
中科院分区：
文献类型：
--
作者：
Collet, JP;Shuman, H;Weisel, JW
血栓需要有适当程度的硬度和可塑性来阻止血液流动，但又能被溶解的酶消化，以免形成血栓，导致心脏病发作、中风或肺血栓，但这些机械特性的来源尚不清楚。凝块是由纤维蛋白纤维的三维网络组成的，纤维纤维通过转谷氨酰胺酶XIIIA因子连接而稳定。我们开发了一种方法来测量纤维蛋白凝块中单个纤维纤维的弹性系数，无论有没有结扎，使用光学镊子捕捉附着在纤维上的珠子，纤维的作用是弯曲或拉伸纤维。在这里，我们报告了对这种聚合物的微观机械性能的直接测量。从纤维的直径和长度来看，纤维在拉伸时比弯曲时要硬得多。血浆凝块中单个纤维的弹性模数未结扎纤维为1.7+/-1.3，结扎纤维为14.5+/-3.5 Mpa。其他独立的方法也得到了类似的值，包括分析由于布朗运动引起的珠子力波动的测量结果。这些结果为理解血栓弹性的起源提供了基础。
A blood clot needs to have the right degree of stiffness and plasticity to stem the flow of blood and yet be digestable by lytic enzymes so as not to form a thrombus, causing heart attacks, strokes, or pulmonary emboli, but the origin of these mechanical properties is unknown. Clots are made up of a three-dimensional network of fibrin fibers stabilized through ligation with a transglutaminase, factor XIIIa. We developed methods to measure the elastic moduli of individual fibrin fibers in fibrin clots with or without ligation, using optical tweezers for trapping beads attached to the fibers that functioned as handles to flex or stretch a fiber. Here, we report direct measurements of the microscopic mechanical properties of such a polymer. Fibers were much stiffer for stretching than for flexion, as expected from their diameter and length. Elastic moduli for individual fibers in plasma clots were 1.7 +/- 1.3 and 14.5 +/- 3.5 MPa for unligated and ligated fibers, respectively. Similar values were obtained by other independent methods, including analysis of measurements of fluctuations in bead force as a result of Brownian motion. These results provide a basis for understanding the origin of clot elasticity.