Synergistic antibacterial and osteogenic properties of micro-arc oxidation GO@Ag/SF composite coatings for the repair of infectious bone defects

Background: Bacterial infection and insufficient osseointegration of titanium-based implants remain major clinical challenges. Conventional drug-loaded coatings often fail to simultaneously achieve long-term antibacterial activity and the construction of an osteogenic microenvironment. Methods: volume ratio, the antibacterial and osteogenic performances of the coatings were systematically evaluated. A rat model of infectious bone defect was employed to verify the in vivo therapeutic efficacy. Results: , with inhibition rates up to 98.3 ± 1.2%. The GO@Ag-2/SF coating also promoted osteogenic differentiation by enhancing ALP activity, collagen secretion, calcium mineralization, and the expression of RUNX-2, ALP, COL-I, and OCN. In vivo, GO@Ag-2/SF reduced inflammatory infiltration and improved peri-implant bone regeneration, with increased BIC, BV/TV, and Tb.Th and reduced Tb.Sp. Moreover, pull-out testing demonstrated the highest bone-implant mechanical fixation in the GO@Ag-2/SF group, confirming enhanced functional osseointegration in the infected bone defect model. Conclusion: Through the synergistic effects of its components, the GO@Ag/SF coating established a dynamic antibacterial-osteogenic balance, offering a promising strategy for the repair of infectious bone defects.