Physical and biological properties of compound membranes incorporating a copolymer with a phosphorylcholine head group.

A copolymer (PMB) having a polar head group 2-methacryloyloxyethyl phosphorylcholine (MPC) copolymerized with n-butyl methacrylate (BMA) may provide a haemocompatible surface for implantable devices. Pure PMB membranes and compound membranes composed of PMB coated onto polyurethane (PU + PMB) and poly(vinyl chloride) (PVC + PMB) have been prepared. Fundamental studies on these membranes included the analysis of molecular distribution and orientation, the characterization of surface physical properties and the examination of blood membrane interactions. The experimental techniques used were Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM) and scanning electron microscopy (SEM). Significant differences between PU + PMB and PVC + PMB membranes were found. Compound PVC + PMB and pure PMB membranes exhibited favourable surface properties for haemocompatibility and also showed low adhesion of blood components, whereas PU + PMB displayed the contrary. This leads to the hypothesis that the underlying material has a major influence on the surface properties of compound membranes.