Effects of fibrinogen residence time and shear rate on the morphology and procoagulant activity of human platelets adherent to polymeric biomaterials
Effects of fibrinogen residence time and shear rate on the morphology and procoagulant activity of human platelets adherent to polymeric biomaterials
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DOI：
10.1097/00002480-200107000-00012
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发表时间：
2001-07-01
期刊：
影响因子：
4.2
通讯作者：
Slack, SM
中科院分区：
文献类型：
--
作者：
Balasubramanian, V;Slack, SM
纤维蛋白原容易吸附到生物材料的表面上，并且由于其被证明具有支持血小板粘附和聚集的能力，在与人体内合成材料的植入相关的血栓形成事件中起作用。因此，了解影响纤维蛋白原与生物材料相互作用的因素，以及血小板反应如何受到影响，对于开发具有改善血液相容性的合成材料至关重要。在这项研究中，纤维蛋白原停留时间和剪切速率的影响，粘附血小板的促凝活性，沿着与他们的形态状态，从扫描电子显微镜推断，进行了研究。为了检查粘附的血小板是否促进凝血酶的产生，将用纤维蛋白原预吸附的聚合物材料（聚四氟乙烯、聚乙烯和硅橡胶）以不同的壁剪切速率暴露于血小板悬浮液，然后在静态条件下与凝血因子孵育5分钟。由通过加入底物S-2238显色的光密度计算每个血小板产生的凝血酶量。血小板的扫描电子显微镜图像显示，血小板表现出不同的形态，这取决于吸附的纤维蛋白原的剪切速率和停留时间，血小板的范围从它们的正常盘状形状主要在静态条件下观察到的，完全展开的血小板。从这项研究的结果表明，血小板，在剪切力的存在下，进行活化暴露于表面上吸附的纤维蛋白原已驻留短的停留时间，而不是长的停留时间。有趣的是，检查这种粘附血小板的促凝血反应的研究表明，粘附于纤维蛋白原包被材料的血小板不会促进显著的凝血酶生成。粘附血小板的这种低凝血酶原酶活性表明，吸附的纤维蛋白原虽然能够支持血小板在生物材料上粘附和铺展，但不一定增强粘附血小板的促凝血活性。
fibrinogen readily adsorbs to the surface of biomaterials and, because of its demonstrated ability to support platelet adhesion and aggregation, plays a role in thrombotic events associated with the implantation of synthetic materials in the human body. Thus, understanding the factors influencing the interactions of fibrinogen with biomaterials, and how platelet responses are affected, is crucial for the development of synthetic materials exhibiting improved blood compatibility. In this study, the effects of fibrinogen residence time and shear rate on the procoagulant activity of adherent platelets, along with their morphologic status, as deduced from scanning electron microscopy, were investigated. To examine whether adherent platelets promoted the generation of thrombin, polymeric materials (polytetrafluoroethylene, polyethylene, and silicone rubber) preadsorbed with fibrinogen were exposed to platelet suspensions at different wall shear rates and then incubated with clotting factors for 5 minutes under static conditions. The amount of thrombin generated per platelet was calculated from the optical density of the color developed by adding substrate S-2238. Scanning electron microscopy images of the platelets revealed that the platelets exhibited different morphologies, depending on the shear rate and residence time of the adsorbed fibrinogen, Platelets ranged from their normal discoid shape observed primarily under static conditions, to that of fully spread platelets. Results from this study show that platelets, in the presence of shear forces, undergo activation on exposure to surfaces on which adsorbed fibrinogen has resided for short residence times rather than long residence times. Interestingly, studies examining the procoagulant responses of such adherent platelets demonstrated that the platelets attached to the fibrinogen coated materials did not promote significant thrombin generation. Such low prothrombinase activity of adherent platelets suggests that adsorbed fibrinogen, while capable of supporting platelet adhesion and spreading on biomaterials, does not necessarily enhance the procoagulant activity of adherent platelets.