壳聚糖静电吸附羧基磷酰胆碱聚合物的研究

Surface modification of chitosan by electrostatic adsorption with polyanion bearing phosphorylcholine groups

采用饥饿法聚合合成了3种不同配比的甲基丙烯酰氧乙基磷酰胆碱-甲基丙烯酸二元共聚物(poly(MPC-co-MA),PMA),并将其静电吸附在壳聚糖表面(CS-PMA)。通过动态接触角(DCA)对影响静电吸附改性的盐及聚合物组成因素进行研究。用X-射线光电子能谱(XPS)、原子力显微镜(AFM)对改性壳聚糖膜的表面元素组成、形貌进行表征,并通过血小板黏附实验对其抗凝血性能进行评价。结果表明,这种利用静电吸附的方式将磷酰胆碱聚合物吸附在壳聚糖表面,可获得具有仿细胞外层膜结构的涂层表面。与壳聚糖相比,改性后壳聚糖可以显著降低对血小板的黏附,抗凝血性能显著提高。该研究为构建仿细胞外层膜结构改善材料血液相容性提供了一种简单、便捷的方法。

Three random copolymers poly (2-methacryloyloxyethyl phosphorylcholine-co-methacrylic acid ) (PMAs)were synthesized by free radical polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid (MA)with different monomer ratios under monomer-starved conditions.The synthesized PMA polyanions were assembled on chitosan (CS)film surfaces via electrostatic adsorption (CS-PMA).The modified surfaces were characterized by dynamic contact angle (DCA),X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM).The anticoagulation property of the surfaces was estimated by platelet ad-hesion measurements.The results indicated that cell outer membrane mimetic structures were formed on the modified surfaces with PMA and the anticoagulation property of the modified surfaces was significantly im-proved.This facile method of fabricating cell outer membrane mimetic surfaces may have potential applications in the fields of hemocompatible coatings,drug delivery,and tissue engineering.