Abstract: XPEO-MDI-PEOX"-type pentablock coupling copolymers were specially designed as the surface additives for poly(ether urethane)(PEU). When the pentablock coupling polymers were blended with PEU, ATR-FTIR indicates that the middle blocks(diphenylmethane diisocyanate(MDI) of the pentablock copolymers could incorporate with the hard blocks of PEU chains through hydrogen binding, which improved the stability of the "XPEO-MDI-PEOX". Based on the special hydrogen binding stabilization and self-migration of "XPEO-MDI-PEOX", RGD presenting surfaces were developed via two different methods. The first approach involved directly blending of RGD-tethered poly(ethylene oxide)-MDI-poly(ethylene oxide)-RGD in PEU. In the second approach, the mesyl-PEO-MDI-PEO mesyl were non-covalently introduced onto the PEU surfaces by dip coating, upon which the RGD was covalently immobilized in situ by cleavage of the original mesyl end groups. The human endothelial cell tests indicate that the RGD presenting films modified by both method could promote endothelial cells attachment and growth significantly. And the cytocompatibility of PEU modified by the first method was better than that by the second method. The two simple methods of surface treatment may have a potential for tissue engineering and other biomedical applications.

Key words: Hydrogen binding, RGD, Poly(ether urethane), Surface modification, Cytocompatibility