MMA/MPC共聚物膜的制备及其抗凝血性能研究

采用自由基共聚制得了甲基丙烯酸甲酯与2-甲基丙烯酰氧基乙基磷酰胆碱(MPC)的共聚物, 在模板中将溶剂蒸发得到了共聚物膜. 用差示扫描量热仪(DSC)、凝胶渗透色谱(GPC)、元素分析仪(EA)、氢核磁共振(¹H NMR)及扫描电子显微镜(SEM)对共聚物及其膜的结构与形态进行了表征, 并测定了膜的溶胀度与表面的亲水性, 结合对牛血清蛋白(BSA)吸附研究结果表明: 共聚物膜的溶胀度随着MPC含量的增加而逐渐上升, 并且随着温度的升高而逐渐增大; 由动态接触角(DCA)结果可知共聚物膜表面的链段可随着环境的变化而发生重排, MPC链段向膜表面的迁移提高了膜表面的亲水性, 降低了对蛋白质的吸附. 并通过体外血小板粘附试验对膜材料的抗凝血性能进行了评价. 结果表明, 当共聚物膜中w(MPC)＝0.25时, 膜表面吸附的血小板数量明显减少, 共聚物膜表现出良好的抗凝血性能.

Preparation and Blood Anticoagulation Activity of Poly(methylmetha- crylate-co-2-methacryloxyethyl phosphorylcholine) Membranes

The copolymers of methyl methacrylate with 2-methacryloxyethyl phosphorylcholine (MPC) were synthesized by solution polymerization. The copolymer membranes were prepared by a solvent evapo- ration method and characterized by differential scanning calorimeter, gel permeation chromatography, ele- mental analysis, 1H nuclear magnetic resonance, and scanning electron microscopy. The equilibrium water content (EWC) and adsorption of bovine serum albumin (BSA) onto the surface of the copolymer mem- branes were studied, while dynamic contact angle (DCA) was used to monitor hydrophilicity of the mem- brane surfaces. It was found that EWC of the copolymer membranes increased with MPC mass content and system temperature. The results of DCA showed that the surface of the membranes could be mobile and able to rearrange depending on the environment in which the membranes were placed. The adsorbed amount of BSA decreased with the increment of MPC mass content in the copolymer membranes, which was able to improve the anticoagulant activity of the membranes. The blood anticoagulation of the membranes was de- termined by a platelet adhesion experiment. It was shown that the copolymer membranes, in which the mass content of MPC was more than 25%, appeared to be beneficial in improving the anticoagulation that was proved to suppress the platelet adhesion.