Influence of hierarchical hybrid micro/nano-structured surface on biological performance of titanium coating

In this article, hierarchical hybrid micro/nano-structured titanium surface was obtained by alkali treating the vacuum plasma sprayed titanium coating following hot water immersing for 24 h. The influences of the surface microstructure on the in vitro and in vivo biologic performance of titanium coating were studied. Human bone marrow-derived stromal cells (hBMSCs) were used for in vitro cytocompatibility evaluation. Compared with the rough titanium coating surface, cell behaviors, such as spread and proliferation were apparently enhanced by mimicking the hierarchical hybrid structure of bone tissue, while ALP expression was lower at days 4 and 7. With the expanding of induction time, the ALP activity rapidly increased on the hierarchical surface. After 10 days induction, it became much higher than that on the rough titanium surface. A canine model was applied for an in vivo evaluation of the bone bonding ability. Histologic examination demonstrated that new bone was formed more rapidly on the hierarchical surface implants than that on the rough titanium surface. All these results indicate that the hierarchical surface is favorable for the response of hBMSCs and early bone bonding.