Bioinspired Mechano-Chemical Titanium Interfaces With Potential for Infection-Resistant Osseointegration

Bacterial colonization and insufficient osseointegration remain major challenges for titanium-based orthopedic and dental implants. Here, we developed a bioinspired mechano-chemical titanium interface by combining an anodization-derived micro-/nano-pitted topography with a polydopamine-citric acid-quercetin (PCQ) functional layer. Inspired by dragonfly-wing micro-/nanostructures, the resulting OPT@PCQ interface exhibited hierarchical topography, enhanced hydrophilicity, and preserved overall mechanical response. OPT@PCQ showed favorable cytocompatibility and significantly promoted osteogenic differentiation of bone marrow-derived mesenchymal stromal cells, with increased alkaline phosphatase activity, matrix mineralization, and RUNX2, COL1A1, and OCN expression. It also displayed pronounced antibacterial activity against Staphylococcus aureus and Escherichia coli, accompanied by bacterial morphological deformation and reduced viability. Transcriptomic analysis of S. aureus revealed broad perturbation of central carbon metabolism, glycolysis/gluconeogenesis, ribosome-associated processes, and stress-response pathways. In vivo, OPT@PCQ promoted wound closure and markedly enhanced new bone formation and trabecular reconstruction in a noninfected rat femoral defect model. Qualitative hemolysis assessment and major-organ histology provided preliminary evidence of hemocompatibility and systemic biosafety under the tested conditions. Collectively, these findings support OPT@PCQ as a multifunctional titanium interface with potential for infection-resistant osseointegration; however, direct validation in an infected bone-defect model remains necessary.