Conclusion
The bionic insect wing AgNPs-PDA@TNN coating exhibited bactericidal property, immunomodulatory ability, and enhanced osteointegration. Thus, this multidimensional bionic implant surface holds promise as a novel strategy to prevent periprosthetic infection.
Methods
We used the hydrothermal method to fabricate a bionic insect wing with the disordered titanium dioxide nanoneedle (TNN) coating. The mussel-inspired poly-dopamine (PDA) and antibacterial silver nanoparticles (AgNPs) were coated on TNN, named AgNPs-PDA@TNN, to improve the biocompatibility and long-lasting bactericidal capacity. The physicochemical properties of the engineered specimen were evaluated with SEM, AFM, XPS spectrum, and water contact assay. The biocompatibility, bactericidal ability, and the effects on macrophages and osteogenic differentiation were assessed with RT-qPCR, Western blotting, live/dead staining, immunofluorescent staining, etc.
Results
The AgNPs-PDA@TNN were biocompatible with macrophages and exhibited immunomodulatory ability to promote M2 macrophage polarization. In addition, AgNPs-PDA@TNN ameliorated the cytotoxicity caused by AgNPs, promoted cell spreading, and increased osteogenesis and matrix deposition of BMSCs. Furthermore, AgNPs-PDA@TNN exhibited bactericidal ability against E. coli and S. aureus by the bionic nanostructure and coated AgNPs. Various imaging analyses indicated the enhanced bactericidal ability and improved new bone formation by AgNPs-PDA@TNN in vivo. H&E, Gram, and Masson staining, verified the improved bone formation, less inflammation, infection, and fibrosis encapsulation. The immunofluorescence staining confirmed the immunomodulatory ability of AgNPs-PDA@TNN in vivo.