Department of Chemical Engineering and School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada.
J Biomater Sci Polym Ed. 2013;24(4):497-506. doi: 10.1080/09205063.2012.690286. Epub 2012 Aug 13.
Measurements of platelet adhesion and fibrinogen adsorption from flowing whole blood to a series of polyethylene oxide (PEO)-based materials were carried out. A unique experimental design was used in which both quantities were measured in the same experiment. The materials consisted of a polyurethane (PU) as a matrix into which various triblock copolymers of general structure PEO-PU-PEO were blended; the PU block was the same in all materials but the PEO blocks ranged in molecular weight from 550 to 5000. Platelets were isolated from fresh human blood and labeled with (51)Cr; purified fibrinogen was labeled with (125)I. A whole blood preparation containing these labeled species was used for the adhesion/adsorption studies. The surfaces were exposed to the flowing blood in a cone and plate device at a wall shear rate of 300 s(-1). It was found that both platelet adhesion and fibrinogen adsorption decreased with increasing copolymer content in the blends and with decreasing PEO block size for a given copolymer content. The block size effect was due probably to higher PEO surface coverage for the lower molecular weight blocks. Fibrinogen adsorption and platelet adhesion were linearly and strongly correlated. The best performing materials showed very low fibrinogen adsorption of the order of 25 ng/cm(2), and correspondingly low platelet densities around 10,000 per cm(2), i.e. fractional platelet coverage in the vicinity of 0.2%.
从流动全血到一系列聚环氧乙烷（PEO）基材料的血小板粘附和纤维蛋白原吸附的测量是在独特的实验设计中进行的，其中在同一实验中同时测量了这两个数量。这些材料由一种聚氨酯（PU）作为基质组成，其中混合了各种具有通用结构的嵌段共聚物 PEO-PU-PEO；PU 块在所有材料中都是相同的，而 PEO 块的分子量从 550 到 5000 不等。血小板从新鲜的人血中分离出来并用（51）Cr 标记；纯化的纤维蛋白原用（125）I 标记。将含有这些标记物的全血制剂用于粘附/吸附研究。在 300 s(-1)的壁剪切速率下，将表面暴露在圆锥和板装置中的流动血液中。结果发现，随着共聚物含量的增加和给定共聚物含量下 PEO 块尺寸的减小，血小板粘附和纤维蛋白原吸附都降低了。块尺寸效应可能是由于低分子量块具有更高的 PEO 表面覆盖率所致。纤维蛋白原吸附和血小板粘附呈线性强相关。表现最好的材料显示出非常低的纤维蛋白原吸附，约为 25 ng/cm(2)，相应的血小板密度约为 10,000 个/cm(2)，即附近的血小板覆盖率接近 0.2%。
