Reprogrammed Implant Surfaces Combat Infection and Boost Bone Integration

Implant-associated infection (IAI) is a major complication that can lead to implant failure. Neutrophils are critical for fighting infection, but their function is impaired by bacterial aggregates and hypoxia. We engineered a new implant surface using phytic acid-Zn2+ nanopillars (PA-Zn@TiNPs) and oxygen-releasing nanoparticles. PA-Zn@TiNPs have a superhydrophilic surface that inhibits bacterial adhesion, nanopillars that kill bacteria, and Zn2+ that eradicates bacteria and prevents biofilm formation. This approach minimizes neutrophil requirements for effective bacterial elimination. Continuous oxygen release from the implant surface fuels neutrophils with reactive oxygen species, enhancing intracellular sterilization. Alleviating hypoxia accelerates neutrophil apoptosis, creating an immunomodulatory osteogenic environment and promoting bone-implant integration. This reprogrammed implant interface empowers neutrophils to prevent IAI and enhance bone integration.