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.