BSA-modified polyethersulfone membrane: preparation, characterization and biocompatibility.

A polyethersulfone (PES) membrane was modified by blending with a co-polymer of acrylic acid (AA) and N-vinyl pyrrolidone (VP), followed by immobilization of bovine serum albumin (BSA) onto the surface. The scanning electron microscopy results showed that PES had good miscibility with the co-polymer. X-ray photoelectron spectroscopy confirmed the existence of P(VP-AA) co-polymer on the surface of the blended membrane and the existence of BSA after the immobilization process. The amount of BSA immobilized on the surface of the membranes was determined. It was found that the protein adsorption amounts from BSA, human plasma fibrinogen and diluted human plasma solutions decreased significantly after modification. According to the circular dichroism results, the proteins kept more alpha-helix conformation in the modified membranes than in the pure PES membrane. The number of the adhered platelets was reduced, and the morphology change for the adherent platelets was also suppressed by the modification with BSA. The SEM morphological observation of the cells and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay demonstrated that the BSA-modified PES membrane surface promoted endothelial cell adhesion and proliferation.