Surface functionalization of styrenic block copolymer elastomeric biomaterials with hyaluronic acid via a "grafting to" strategy.

As a biostable elastomer, the hydrophobicity of styrenic block copolymer (SBC) intensely limits its biomedical applications. In order to overcome such shortcoming, the SBC films were grafted with hyaluronic acid (HA) using a coupling agent. The surface chemistry of the modified films was examined by ATR-FTIR and XPS techniques, and the surface morphology was visually described by AFM. The biological performances of the HA-modified films were evaluated by a series of experiments, such as protein adsorption, platelet adhesion, and in vitro cytocompatibility. It was found that the HA-modified samples showed a low adhesiveness to fibroblast at the initial stage; however, it stimulated the growth of fibroblast. The L929 fibroblast growth presented a strong dependence on the molecular weight (MW) of HA. The samples modified with 17kDa HA exhibited the worst wettability and platelet adhesion, while providing the best results of supporting fibroblast proliferation.