Vancomycin-encapsulated hydrogel loaded microarc-oxidized 3D-printed porous Ti6Al4V implant for infected bone defects: Reconstruction, anti-infection, and osseointegration.

Abstract

Infected bone defect is a formidable clinical challenge. Conventional approaches to prevention and treatment for infected bone defects are unsatisfactory. The key elements of the treatment are bone defect reconstruction, anti-infection, and osteogenesis. Conventional treatment methods remain unsatisfactory owing to the absence of composite integrating materials with anti-infective, and osteogenic activities as well as proper mechanical strength at the same time. In this study, we fabricated a vancomycin-encapsulated hydrogel with bacteria-responsive release properties combined with a shaved porous (submicron-micron) three-dimensional-printed Ti6Al4V implant. The implant surface, modified with submicron-sized pores through microarc oxidation (MAO), showed enhanced osteogenic activity and integrated well with the hydrogel drug release system, enabling sustained vancomycin release. <i>In vitro</i> experiments underscored the commendable antibacterial ability, biosafety, and osteoinductive potential. Effective antibacterial and osteogenic abilities of the implant were further demonstrated <i>in vivo</i> in infected rabbit bone defects. These results showed that the vancomycin-encapsulated hydrogel-loaded microarc-oxidized 3D-printed porous Ti6Al4V can repair the infected bone defects with satisfactory anti-infection and osseointegration effects.