Combinatorial Microfluidic Devices for Studying Thrombosis

描述（由申请人提供）：描述。拟议研究的目的是了解血小板表面凝血酶的生成如何稳定血凝块。凝血酶在凝块形成中的主要作用是催化纤维蛋白聚合和激活血小板。这两种机制中哪一种对凝块稳定性最负责，以及在何种流动条件下最负责，目前尚不清楚。本研究的中心假设是，在静脉剪切应力下，稳定的血块可以在没有血小板激活的情况下形成，但在动脉剪切应力下，血小板激活是稳定血块的主要机制。为了研究凝块的稳定性，我们将使用一种新型的微流体工具将可溶性因子引入流动的血液中。这种方法的基本原理是血液在体内是一种移动的生物流体，因此在生理相关的流动条件下研究体外血液表型是重要的。所产生的凝块的形成和形态将通过相衬、荧光和电子显微镜方法来测量。通过分析其在高剪切应力作用下的破碎情况，可以确定凝块的稳定性。这一创新方法预计将产生以下结果。在具体目标1中，我们将确定凝血酶通量如何。影响纤维蛋白聚合，这是重要的，因为它将确定所需的凝血酶的量下流动形成纤维蛋白凝块。在具体目标2中，我们将分离纤维蛋白聚合和血小板活化，以确定这两种机制在形成稳定凝块中的相对作用。通过分离不同血流条件下导致凝块稳定性的机制，我们期望进一步了解出血性疾病和栓塞的病理。总结。这项研究的目的是了解形成稳定血凝块的机制。凝块稳定性差是血友病等出血性疾病的结果，也是由先前存在的凝块脱落的栓塞引起中风的原因。通过揭示凝块稳定性的机制，本研究将为患有这些疾病的个体确定新的治疗靶点。

DESCRIPTION (provided by applicant): DESCRIPTION. The goal of the proposed research is to understand how the generation of thrombin at the surface of platelets stabilizes blood clots. The primary roles of thrombin in clot formation are to catalyze fibrin polymerization and activate platelets. Which of these two mechanisms is most responsible for clot stability and under what flow conditions is unknown. The central hypothesis for the proposed research is that at venous shear stresses, stable clots can form in the absence of platelet activation but at arterial shear stress, platelet activation is the predominant mechanism for stabilizing clots. To study clot stability, we will use a novel microfluidic tool to introduce soluble factors into flowing blood. The rationale for this approach is that blood is a moving biological fluid in vivo, and therefore it is important to study blood phenotype in vitro under physiologically relevant flow conditions. The formation and morphology of the resultant clots will be measured by phase contrast, fluorescence, and electron microscopy methods. The stability of clot will be determined by analyzing its fragmentation under high shear stress. This innovative approach is expected to yield the following outcomes. In specific aim 1, we will determine how thrombin flux.affects fibrin polymerization, which is important because it will identify the amount of thrombin generation needed under flow to form a fibrin clot. In specific aim 2, we will decouple fibrin polymerization from platelet activation to determine the relative role of these two mechanisms in forming stable clots. By isolating the mechanism(s) that are responsible for clot stability at different flow conditions we expect to gain further insight into the pathology of bleeding disorders and embolism. LAY SUMMARY. The goal of this research is to understand the mechanisms responsible for forming stable blood clots. Poor clot stability is the result of bleeding disorders like hemophilia and the cause of stroke by emboli shedding from preexisting clots. By unraveling the mechanisms responsible for clot stability, this research will identify new therapeutic targets for individuals who suffer from these diseases.