Rahman Shekh Mojibur, Hlady Vladimir
Department of Chemical Engineering, University of Utah, Salt Lake City, UT 84112, USA.
Lab Chip. 2021 Jan 5;21(1):174-183. doi: 10.1039/d0lc00756k.
We have developed a microfluidic system to perfuse whole blood through a flow channel with an upstream stenotic region and a downstream protein capture region. This flow-based system was used to assay how effectively antiplatelet agents suppress shear-induced platelet adhesion and activation downstream of the stenotic region. Microcontact printing was used to covalently attach one of three platelet binding proteins [fibrinogen, collagen, or von Willebrand factor (vWf)] to the surface of the downstream capture region. Whole blood with an antiplatelet agent was transiently exposed to an upstream high wall shear rate (either 4860 s-1 or 11 560 s-1), and subsequently flowed over the downstream capture region where the platelet adhesion was measured. Several antiplatelet agents (acetylsalicylic acid, tirofiban, eptifibatide, anti-vWf, and anti-GPIbα) were evaluated for their efficacy in attenuating downstream adhesion. Following antibody blocking of vWf or GPIbα, downstream platelet activation was also assessed in perfused blood by flow cytometry using two activation markers (active GPIIb/IIIa and P-selectin). Acetylsalicylic acid demonstrated its inability to diminish shear-induced platelet adhesion to all three binding proteins. GPIIb/IIIa inhibitors (tirofiban and eptifibatide) significantly reduced platelet adhesion to fibrinogen. Antibody blocking of vWf or GPIbα effectively diminished platelet adhesion to all three capture proteins as well as platelet activation in perfused blood, indicating an essential role of vWf-GPIbα interaction in mediating shear-induced platelet aggregation.
我们开发了一种微流控系统，用于使全血通过一个带有上游狭窄区域和下游蛋白质捕获区域的流动通道。这个基于流动的系统被用于测定抗血小板药物在狭窄区域下游抑制剪切诱导的血小板黏附和激活的效果。微接触印刷被用于将三种血小板结合蛋白之一（纤维蛋白原、胶原蛋白或血管性血友病因子（vWf））共价连接到下游捕获区域的表面。含有抗血小板药物的全血短暂暴露于上游高壁剪切速率（4860 s-1或11560 s-1），随后流过下游捕获区域，在那里测量血小板黏附情况。评估了几种抗血小板药物（乙酰水杨酸、替罗非班、依替巴肽、抗vWf和抗GPIbα）在减弱下游黏附方面的效果。在用抗体阻断vWf或GPIbα后，还通过流式细胞术使用两种激活标记物（活性GPIIb/IIIa和P-选择素）在灌注血液中评估下游血小板激活情况。乙酰水杨酸显示出无法减少剪切诱导的血小板与所有三种结合蛋白的黏附。GPIIb/IIIa抑制剂（替罗非班和依替巴肽）显著降低了血小板与纤维蛋白原的黏附。用抗体阻断vWf或GPIbα有效地减少了血小板与所有三种捕获蛋白的黏附以及灌注血液中的血小板激活，表明vWf-GPIbα相互作用在介导剪切诱导的血小板聚集中起重要作用。
