PREPARATION AND CHARACTERIZATION OF POLY( 2-METHACRYLOYLOXYETHYL PHOSPHORYLCHOLINE-CO-METHYL METHACRYLATE) GRAFT COPOLYETHERURETHANES

In order to improve the biocompatibility of polyurethane, a series of graft copolyurethanes (gPEU-II similar to VI) were prepared by using a macromonomer technique. Dihydroxy-terminated macromonomer, Mac(MPC/MM A), was prepared by radical polymerization of 2-methacryloyloxyethyl p hosphorylcholine (MPC) and methyl methacrylate (MMA) with 2,2'-azobis( isobutyronitrile) (AIBN) in the presence of thioglycerol as a chain tr ansfer agent. Polycondensation of polyethylene glycol (or polypropylen e glycol) and diisocyanate was carried out in the presence of Mac (MPC /MMA) in dimethyl sulfoxide (DMSO) to give gPEU-III similar to VI with [eta] = 0.13 similar to 0.20 dL . g(-1). Diisocyanates used were toly lene 2,4-diisocyanate and 4,4'-diphenylmethane diisocyanate. Graft cop olyurethane gPEU-II as a control was also prepared by using dihydroxy- terminated macromonomer of MMA, Mac(MMA). XPS measurements showed that MPC moieties and polyethylene segments in gPEU-III similar to VI were located on the surface of wet polymer films. It was found that gPEU-I II similar to VI suppresses the adsorption of bovine serum albumin les s than gPEU-II did as the control. In cell culture test, films prepare d from gPEU-III similar to VI showed no adhesiveness of mouse fibrobla st (L-929). These findings indicate that the modification of the surfa ce of polyurethane with MPC moieties is useful for improving biocompat ibility.