Ishihara K, Shibata N, Tanaka S, Iwasaki Y, Kurosaki T, Nakabayashi N
Institute for Medical and Dental Engineering, Tokyo Medical and Dental University, Japan.
J Biomed Mater Res. 1996 Nov;32(3):401-8. doi: 10.1002/(SICI)1097-4636(199611)32:3<401::AID-JBM13>3.0.CO;2-J.
To improve the blood compatibility of a segmented polyurethane (SPU), phospholipid polymer, i.e., 2-methacryloyloxyethyl phosphorylcholine (MPC) copolymerized with cyclohexyl methacrylate or 2-ethylhexyl methacrylate, was blended into SPU as a polymeric additive. The blending was achieved by a solvent-evaporation technique from a homogeneous solution containing both the SPU and the MPC polymer. Surface analysis of the SPU membrane blended with the MPC polymer (SPU/MPC polymer membrane) revealed that the MPC polymer was concentrated at the surface of the SPU membrane which contacted the substrate, Teflon, compared with that which contacted air during the membrane-formation period. The dispersion state of the MPC polymer in the SPU membrane was evaluated in detail by staining the MPC unit with osmium tetraoxide. When sonication was applied during preparation of the mixed solution containing SPU and the MPC polymer, the dispersion of the MPC polymer in the SPU membrane was different from that without sonication. That is, the size of the domains of the MPC polymer became smaller but the number of the domains increased. The amount of the MPC polymer mixed with SPU affected the dispersion state. Plasma proteins adsorbed on the SPU/MPC polymer membrane surface after contact with human plasma were detected by gold-colloid-labeled immunoassay. Both albumin and fibrinogen were observed on the SPU membrane; however, the amount of these proteins was reduced on the SPU/MPC polymer membrane. Thus it was concluded that the blood compatibility of the SPU was effectively improved by the blending of the MPC polymer.
为提高嵌段聚氨酯（SPU）的血液相容性，将磷脂聚合物，即与甲基丙烯酸环己酯或甲基丙烯酸2-乙基己酯共聚的2-甲基丙烯酰氧基乙基磷酰胆碱（MPC）作为聚合物添加剂混入SPU中。通过溶剂蒸发技术，从含有SPU和MPC聚合物的均匀溶液中实现混合。对混入MPC聚合物的SPU膜（SPU/MPC聚合物膜）进行表面分析发现，与成膜期间接触空气的表面相比，MPC聚合物集中在与基材聚四氟乙烯接触的SPU膜表面。通过用四氧化锇对MPC单元进行染色，详细评估了MPC聚合物在SPU膜中的分散状态。在制备含有SPU和MPC聚合物的混合溶液时施加超声处理，MPC聚合物在SPU膜中的分散情况与未施加超声处理时不同。也就是说，MPC聚合物域的尺寸变小，但域的数量增加。与SPU混合的MPC聚合物的量影响分散状态。通过金胶体标记免疫测定法检测与人体血浆接触后吸附在SPU/MPC聚合物膜表面的血浆蛋白。在SPU膜上观察到白蛋白和纤维蛋白原；然而，在SPU/MPC聚合物膜上这些蛋白质的量减少。因此得出结论，通过混入MPC聚合物可有效提高SPU的血液相容性。
