Tutwiler Valerie, Wang Hailong, Litvinov Rustem I, Weisel John W, Shenoy Vivek B
Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; School of Biomedical Engineering, Sciences and Health Systems, Drexel University, Philadelphia, Pennsylvania.
Department of Modern Mechanics, CAS Key Laboratory of Mechanical Behavior and Design of Materials, University of Science and Technology of China, Hefei, Anhui, China; Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania.
Biophys J. 2017 Feb 28;112(4):714-723. doi: 10.1016/j.bpj.2017.01.005.
Blood clot contraction (retraction) is driven by platelet-generated forces propagated by the fibrin network and results in clot shrinkage and deformation of erythrocytes. To elucidate the mechanical nature of this process, we developed a model that combines an active contractile motor element with passive viscoelastic elements. Despite its importance for thrombosis and wound healing, clot contraction is poorly understood. This model predicts how clot contraction occurs due to active contractile platelets interacting with a viscoelastic material, rather than to the poroelastic nature of fibrin, and explains the observed dynamics of clot size, ultrastructure, and measured forces. Mechanically passive erythrocytes and fibrin are present in series and parallel to active contractile cells. This mechanical interplay induces compressive and tensile resistance, resulting in increased contractile force and a reduced extent of contraction in the presence of erythrocytes. This experimentally validated model provides the fundamental mechanical basis for understanding contraction of blood clots.
血凝块收缩（回缩）由血小板产生的力驱动，该力通过纤维蛋白网络传播，导致血凝块收缩以及红细胞变形。为阐明这一过程的力学本质，我们开发了一个模型，该模型将主动收缩运动元件与被动粘弹性元件相结合。尽管血凝块收缩对血栓形成和伤口愈合至关重要，但人们对其了解甚少。该模型预测了由于主动收缩的血小板与粘弹性材料相互作用而导致的血凝块收缩，而非由于纤维蛋白的多孔弹性性质，并解释了观察到的血凝块大小、超微结构和测量力的动态变化。机械上被动的红细胞和纤维蛋白与主动收缩细胞串联和平行存在。这种机械相互作用产生压缩和拉伸阻力，导致在存在红细胞的情况下收缩力增加而收缩程度降低。这个经过实验验证的模型为理解血凝块收缩提供了基本的力学基础。
