Formation of a novel Cu-containing bioactive glass nano-topography coating with strong bactericidal capability and bone regeneration

Implant-related infection (IRI) is a disastrous complication after total joint arthroplasty (TJA). Due to its cytocompatibility and mechanically resistance, titanium (Ti) has been recognized as suitable bone implant materials. However, Ti lacks bioactivity and is vulnerable to bacterial infection. In this study, we developed an innovative surface coating using electrophoretic deposition (EPD) to overcome those limitations. The coating was composed of (i) a natural biocompatibility polymer Chitosan (Chit), and (ii) a novel copper-doped bioactive glass nanoparticles (Cu-BGNs) with antibacterial and pro-osteogenic properties. In vitro experiments showed that this coating endowed the Ti surface with the ability to promote macrophage M1 polarization through topography cues and released copper ions. The coating combining immunoregulatory antibacterial effects with transient bactericidal activity led to synergetic effects against IRIs. Furthermore, the coated Ti implants exerted favorable osteo-immunomodulatory effects towards enhanced osteogenic abilities as evidenced in vitro and in vivo. This strategy combining Cu-BGNs-Chit composites and EPD provides novel strategies for designing and fabricating immunomodulatory implants targeting IRIs.