In vitro and in vivo evaluation of hierarchical porous structure for osteogenic differentiation promotion

The hierarchical micro-nano porous structure in this study was prepared on the surface of Ti-3Zr-2Sn-3Mo-25Nb (TLM) titanium alloy by electrochemical dealloying process, in which the size of the micro-grooves was 2.42 ± 0.83 μm in length and 0.58 ± 0.12 μm in width, and the size of the nanopores was 14.6 ± 0.57 nm. The hierarchical porous structure was detected to significantly reduce the surface roughness and enhance wettability, which is beneficial for the adhesion and spreading of cells. Notably, the hierarchical porous structure remarkably up-regulated osteogenic differentiation and inhibited adipogenic differentiation. The relevant mechanism can be explained as micro-scale grooves induced cell morphology and then guided differentiation behavior. In addition, the hierarchical porous structure also increased the contact area between the bone and the implant, and induced more new bone formation.