Iwasaki Y, Ijuin M, Mikami A, Nakabayashi N, Ishihara K
Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10, Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
J Biomed Mater Res. 1999 Sep 5;46(3):360-7. doi: 10.1002/(sici)1097-4636(19990905)46:3<360::aid-jbm8>3.0.co;2-z.
Omega-Methacryloyloxyalkyl phosphorylcholine (MAPC) polymer, which has various methylene chain lengths between the phosphorylcholine group and the backbone, was synthesized with attention to formation of the biomembrane. The effect of water-soluble poly(MAPC) on the function and activation of blood cells was evaluated to determine the interaction between blood cells and the MAPC polymer. The poly(MAPC) and the MAPC copolymer with a small amount of fluorescent units were synthesized by a conventional radical polymerization technique. Using a fluorescence spectrometer, it was determined that the MAPC polymer was adsorbed on the plasma membrane of platelets when the platelets were suspended in an aqueous solution of the MAPC copolymer. The hemolytic activity of poly(MAPC) was less than that of other water-soluble polymers, such as poly(ethylene glycol) and poly(1-vinyl-2-pyrrolidone) (PVPy). The change in the plasma membrane fluidity of platelets on contact with poly(MAPC) was determined with 1,6-diphenyl-1,3,5,-hexatriene. The plasma membrane fluidity of platelets decreased with an increase in the methylene chain length of the MAPC unit. The aggregation activity of platelets after contact with poly(MAPC) was also evaluated, but no significant difference between that of polymer-contacted platelets and native platelets was observed. Finally, the activity of platelets on contact with poly(MAPC) was determined by measuring the cytoplasmic calcium ion concentration ([Ca2+]i) in platelets. The increase in [Ca2+]i in the platelets after contact with poly(MAPC) was similar to that of native platelets. We conclude that the poly(MAPC) reduced platelet activation even though the poly(MAPC) adsorbed on the membrane surface of the platelets. In particular, poly(10-methacryloyloxydecyl phosphorylcholine) significantly reduced platelet activation compared with PVPy.
ω-甲基丙烯酰氧基烷基磷酰胆碱（MAPC）聚合物在磷酰胆碱基团与主链之间具有不同的亚甲基链长度，其合成过程着重考虑了生物膜的形成。评估了水溶性聚（MAPC）对血细胞功能和活化的影响，以确定血细胞与MAPC聚合物之间的相互作用。通过常规自由基聚合技术合成了聚（MAPC）和带有少量荧光单元的MAPC共聚物。使用荧光光谱仪测定，当血小板悬浮于MAPC共聚物的水溶液中时，MAPC聚合物吸附在血小板的质膜上。聚（MAPC）的溶血活性低于其他水溶性聚合物，如聚乙二醇和聚（1-乙烯基-2-吡咯烷酮）（PVPy）。用1,6-二苯基-1,3,5-己三烯测定了血小板与聚（MAPC）接触后质膜流动性的变化。血小板的质膜流动性随着MAPC单元亚甲基链长度的增加而降低。还评估了血小板与聚（MAPC）接触后的聚集活性，但未观察到接触聚合物的血小板与天然血小板之间存在显著差异。最后，通过测量血小板中的细胞质钙离子浓度（[Ca2+]i）来确定血小板与聚（MAPC）接触后的活性。与聚（MAPC）接触后血小板中[Ca2+]i的增加与天然血小板相似。我们得出结论，尽管聚（MAPC）吸附在血小板的膜表面，但它降低了血小板的活化。特别是，与PVPy相比，聚（10-甲基丙烯酰氧基癸基磷酰胆碱）显著降低了血小板的活化。
