Grafting of a novel phosphorylcholine-containing vinyl monomer onto poly-carbonateurethane surfaces by ultraviolet radiation grafting polymerization

An original phosphorylcholine (PC) containing vinyl monomer (compound 1) was grafted onto the surface of polycarbonate urethane (PCU) films by ultraviolet (UV) initiated polymerization. The vinyl monomer was synthesized from 2-hydroxyethyl methacrylate (HEMA), hexamethylene diisocyanate (HDI) and L-alpha-glycerylphosphorylcholine (GPC) by two relative reactions through the coupling of the isocyanate groups in HDI with the hydroxyl groups in HEMA and GPC, respectively. The existence of phosphorylcholine groups on the surface of compound 1-grafted PCU films was verified by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and water contact angle measurements. The surfaces of the grafted PCU films showed lower water contact angles than did the surfaces of non-grafted PCU films. Furthermore, the surface morphology of a grafted PCU film was observed using scanning electrical microscopy (SEM), which showed that the grafted polymer film exhibits a rough and pinhole-free surface. In addition, the blood compatibility of the compound 1-grafted PCU films was evaluated by platelet adhesion studies using the non-grafted PCU film as a reference. It was found by SEM that fewer platelets adhered to the surfaces of the grafted PCU films compared to the reference. The high PC-grafted PCU film did not show any substantial platelet attachment on its surface. These results indicated that these compound 1-grafted polymers may have potential application as biomaterials for vascular grafts and some subcutaneously implanted devices.