Sulfonated porous surface of tantalum pentoxide/polyimide composite with micro-submicro structures displaying antibacterial performances and stimulating cell responses

To improve the surface bio-performances of polyimide (PI), tantalum pentoxide (Ta 2 O 5 )/PI composites (TPC) were prepared, and concentrated sulfuric acid was utilized to modify TPC surface. The results revealed that sulfonated TPC (STPC) exhibited microporous surface with pores size of about 3 μm, and sulfonic acid (-SO 3 H) groups were introduced onto the microporous surface. In addition, many Ta 2 O 5 submicro particles appeared on the microporous surface, which formed micro-submicro structures. Compared with PI, the surface roughness, hydrophilicity, surface energy and protein adsorption as well as apatite mineralization of STPC in simulated body fluid were obviously enhanced, which increased with Ta 2 O 5 content increasing. In addition, STPC exhibited antibacterial performances due to the presence of -SO 3 H groups and Ta 2 O 5 . Furthermore, the responses (adhesion, proliferation and differentiation) of rat bone marrow mesenchymal stem cells to STPC were remarkably promoted with the increase of Ta 2 O 5 content. In short, STPC with 50w% Ta 2 O 5 content (STPC 50) with sulfonated microporous surface contained micro-submicro structures, which exhibited antibacterial performances and stimulated cell responses. STPC50 with improved surface properties and cytocompatibility might have large potentials for bone repair applications.