A novel porous titanium with engineered surface for bone defect repair in load‐bearing position

Abstract Porous titanium exhibits low elastic modulus and porous structure is thought to be a promising implant in bone defect repair. However, the bioinert and low mechanical strength of porous titanium have limited its clinical application, especially in load‐bearing bone defect repair. Our previous study has reported an infiltration casting and acid corrosion (IC‐AC) method to fabricate a novel porous titanium (pTi) with 40% porosity and 0.4 mm pore diameter, which exerts mechanical property matching with cortical bone and interconnected channels. In this study, we introduced a nanoporous coating and incorporated an osteogenic element strontium (Sr) on the surface of porous titanium (named as Sr‐micro arch oxidation [MAO]) to improve the osteogenic ability of the pTi by MAO. Better biocompatibility of Sr‐MAO was verified by cell adhesion experiment and cell counting kit‐8 (CCK‐8) test. The in vitro osteogenic‐related tests such as immunofluorescence staining, alkaline phosphatase staining and real‐time polymerase chain reaction (RT‐PCR) demonstrated better osteogenic ability of Sr‐MAO. Femoral bone defect repair model was employed to evaluate the osseointegration of samples in vivo. Results of micro‐CT scanning, sequential fluorochrome labeling and Van Gieson staining suggested that Sr‐MAO showed better in vivo osteogenic ability than other groups. Taking results of both in vitro and in vivo experiment together, this study indicated the Sr‐MAO porous titanium could be a promising implant load‐bearing bone defect.