Gemmell C H
Department of' Medicine, University of Toronto, Ontario, Canada.
J Biomater Sci Polym Ed. 2001;12(8):933-43. doi: 10.1163/156856201753113114.
Non-adherent platelets and plasma were analyzed for evidence of platelet activation after whole blood contact with materials under conditions of low shear for one hour at 37 degrees C. The contact involved adding heparinized whole blood to small diameter tubes that were connected to two arms extending from a rocking platform. For all surfaces (polyethylene, polypropylene, Silastic, PVA hydrogel) tested there was strong evidence of platelet activation in the bulk blood: platelet-derived microparticles, procoagulant platelet membranes and soluble P-selectin levels. Flow cytometric quantification of microparticles (MPs) was highly sensitive and entailed the direct determination of microparticle concentrations as opposed to the traditional quantification of microparticle percentages (relative to total number of MPs and platelets). Whole blood contact with polypropylene surfaces led to the greatest drops in bulk platelet counts and also to the lowest increases in microparticle concentrations. Flow cytometry was also used to assess procoagulant levels (annexin V binding) within a light scatter region known to contain platelets and some large microparticles. All surfaces were noted to generate a significant procoagulant population that was, based on forward light scatter, mostly very small platelets or large microparticles. In contrast, most of the P-selectin positive platelets were averaged sized. Lastly. all surfaces generated soluble P-selectin levels that were approximately double the level (25 ng ml(-1)) noted in the resting whole blood samples. In addition to our previous reports, these findings support the observation that there is strong evidence of platelet activation in the bulk that we anticipate will ultimately lead to more relevant in vitro testing of the compatibility of platelets towards materials.
在37摄氏度下，将全血与材料在低剪切条件下接触一小时后，对非黏附血小板和血浆进行分析，以寻找血小板激活的证据。这种接触是通过将肝素化全血添加到连接到从摇摆平台伸出的两个臂的小直径管中来实现的。对于所有测试表面（聚乙烯、聚丙烯、硅橡胶、聚乙烯醇水凝胶），在全血中均有强有力的证据表明存在血小板激活：血小板衍生的微粒、促凝血小板膜和可溶性P-选择素水平。微粒（MPs）的流式细胞术定量非常灵敏，与传统的微粒百分比定量（相对于微粒和血小板总数）不同，它直接测定微粒浓度。全血与聚丙烯表面接触导致全血血小板计数下降幅度最大，微粒浓度增加幅度最小。流式细胞术还用于评估已知含有血小板和一些大微粒的光散射区域内的促凝水平（膜联蛋白V结合）。所有表面均产生了大量促凝物质，根据前向光散射，这些物质大多是非常小的血小板或大微粒。相比之下，大多数P-选择素阳性血小板大小平均。最后，所有表面产生的可溶性P-选择素水平约为静息全血样本中水平（25 ng ml(-1)）的两倍。除了我们之前的报告外，这些发现支持了这样的观察结果，即有强有力的证据表明全血中存在血小板激活，我们预计这最终将导致对血小板与材料相容性进行更相关的体外测试。
