Abstract: 2-Methacryloyloxyethyl phosphorylcholine(MPC), a hydrophilic monomer mimicking the cell outer membrane structure, was copolymerized with hydrophobic monomer stearyl methacrylate(SMA), lauryl methacrylate(LMA) and n-butyl methacrylate(BMA), respectively, by monomer-starved polymerization technique. By changing the molar ratio of the monomers in feed, a series of amphiphilic biomembrane mimetic copolymers bearing different hydrophobic alkyl chain groups was synthesized. The ¹H NMR and elemental analysis results showed that the compositions of the amphiphilic random bipolymers were similar to the ratios in feed. The DSC results suggested that the glass transition temperature of these copolymers were low. The surface tension measurement indicated that the copolymer coatings rarely dissolved in water. The dynamic contact angles(DCA) of the copolymer coatings in water suggested a changeable surface structure of the coating. When exposed in air, the hydrophobic alkyl chains of the coating oriented onto the surface; while in aqueous conditions, the hydrophilic phosphorylcholine groups migrated and oriented onto the interface to form the cell outer membrane mimetic structure. This study provides theoretical support for improving the biocompatibility of biomaterials simply by immersing in or spraying with the solutions of the cell membrane mimetic amphiphilic copolymers.

Key words: Phosphorylcholine, Amphiphilic copolymer, Biomembrane mimetic structure, Biocompatibility, Contact angle(CA)