Kulik E, Ikada Y
Research Center for Biomedical Engineering, Kyoto University, Japan.
J Biomed Mater Res. 1996 Mar;30(3):295-304. doi: 10.1002/(SICI)1097-4636(199603)30:3<295::AID-JBM4>3.0.CO;2-L.
To investigate in vitro platelet adhesion to hydrogels, using electron-beam irradiation, polymer reaction, and radical polymerization, hydrogels were synthesized to have a wide range of water content. The nonionic synthesized hydrogels include polyacrylamide (PAAm), poly(vinyl alcohol) (PVA), poly(ethylene glycol) (PEG), poly(N-vinyl pyrrolidone), and poly(methoxy-PEG methacrylate) while the ionic hydrogels were crosslinked poly(AAm-acrylic acid) and poly(AAm-dimethylaminoethyl methacrylate) copolymers. Adhesion of washed rabbit platelets to these hydrogels were studied in phosphate-buffered saline for 30 min. In the case of PVA and PAAm hydrogels, platelet adhesion also was conducted in the presence of proteins. The protein sorption into PVA hydrogel was studied by fluorescent spectroscopy. It was found that all the nonionic hydrogels exhibited a lower level of platelet adhesion than did conventional hydrophobic polymers, such as medical-grade poly(vinyl chloride), polyurethane, and silicone, and they exhibited the minimum platelet adhesion at a water content of around 90%. PAAm and PEG hydrogels had the weakest interaction with platelets when the water content was lower than 90%. PVA hydrogel showed the highest platelet adhesion in the low-water-content region, but the platelet adhesion was greatly reduced in the presence of proteins. Significant protein sorption was noted when the water content of PVA hydrogel was as high as 80%. Introduction of a positive charge into the PAAm hydrogel promoted platelet adhesion whereas the negative charge introduced into the hydrogel slightly reduced the number of adhered platelets.
为了研究体外血小板对水凝胶的黏附情况，通过电子束辐照、聚合物反应和自由基聚合合成了具有广泛含水量的水凝胶。合成的非离子水凝胶包括聚丙烯酰胺（PAAm）、聚乙烯醇（PVA）、聚乙二醇（PEG）、聚N-乙烯基吡咯烷酮和聚（甲氧基-PEG甲基丙烯酸酯），而离子水凝胶是交联的聚（AAm-丙烯酸）和聚（AAm-甲基丙烯酸二甲氨基乙酯）共聚物。在磷酸盐缓冲盐溶液中研究了洗涤后的兔血小板对这些水凝胶的黏附情况，持续30分钟。对于PVA和PAAm水凝胶，还在有蛋白质存在的情况下进行了血小板黏附实验。通过荧光光谱研究了蛋白质在PVA水凝胶中的吸附情况。结果发现，所有非离子水凝胶的血小板黏附水平均低于传统的疏水性聚合物，如医用级聚氯乙烯、聚氨酯和硅酮，并且它们在含水量约为90%时表现出最小的血小板黏附。当含水量低于90%时，PAAm和PEG水凝胶与血小板的相互作用最弱。PVA水凝胶在低含水量区域表现出最高的血小板黏附，但在有蛋白质存在的情况下，血小板黏附大大降低。当PVA水凝胶的含水量高达80%时，观察到显著的蛋白质吸附。向PAAm水凝胶中引入正电荷促进了血小板黏附，而向水凝胶中引入负电荷则略微减少了黏附的血小板数量。
