Surface modification of poly(ether ether ketone) with methacryloyl-functionalized phospholipid polymers via self-initiation graft polymerization.

To improve blood compatibility of poly(ether ether ketone) (PEEK), surface modification with methacryloyl-functionalized phospholipid polymers was performed through self-initiation graft polymerization. The copolymers (PMA) of 2-methacryloyloxyethyl phosphorylcholine (MPC) and 2-aminoethyl methacrylate hydrochloride were synthesized by conventional free radical polymerization. The PMA was then immobilized with pentafluorophenyl methacrylate to obtain methacryloyl-functionalized MPC polymers (PMAMA). The degree of substitution of the methacryloyl group into the copolymer was nearly completed. The PMAMA was dissolved in 1-butanol and the solution was dropped on PEEK. UV light (350±50 nm) was subsequently irradiated on PEEK for various periods. Elemental analysis of the PEEK surface was performed by X-ray photoelectron spectroscopy and phosphorus and nitrogen signals due to the MPC units on PEEK were observed. The surface wettability of PEEK was also improved by immobilization of PMAMA. Plasma protein adsorption was effectively reduced on the PMAMA-immobilized surface regardless of the type of protein. Furthermore, PMAMA immobilization was also useful in reducing platelet adhesion on PEEK. In conclusion, methacryloyl-functionalized MPC polymers could be immobilized on PEEK by simple photo-irradiation, resulting in significant improvement in blood compatibility.