Heparin-like surface modification of polyethersulfone membrane and its biocompatibility.

Sulfonated polyethersulfone (SPES) and poly (acrylonitrile-co-acrylic acid-co-vinyl pyrrolidone) (P(AN-AA-VP)), which provided sulfonic acid (-SO(3)H) and carboxylic acid groups (-COOH), respectively, were used to modify polyethersulfone (PES) membrane with a heparin-like surface by blending method. The SPES was prepared by sulfonation of PES using chlorosulfonic acid as the sulfonating agent, while the P(AA-AN-VP) was prepared through a free radical polymerization. The PES and modified PES membranes were prepared by a phase-inversion technique; the modified membranes showed lowered protein (bovine serum albumin, BSA; bovine serum fibrinogen, FBG) adsorption and suppressed platelet adhesion. For the modified membranes, significant decreases in thrombin-antithrombin (TAT) generation, percentage platelets positive for CD62p expression, and the complement activation on C3a and C5a levels were observed compared with those for the pure PES membrane. Due to the similar negatively charged groups as heparin, the modified membranes effectively prolonged the activated partial thromboplastin time (APTT). Furthermore, the modified membranes showed good cytocompatibility. Hepatocytes cultured on the modified materials exhibited improved functional profiles in terms of scanning electron microscope (SEM) observation and 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay compared with those on the pure PES membrane. It could be concluded that the modified membranes with sulfonic acid and carboxylic acid groups were endowed with excellent biocompatibility, and the heparin-like surface modification seemed to be a promising approach to improve the biocompatibility of materials.