In situ growth of Zn-MOFs coating on magnesium implants induced by graphene oxide with synergistic antibacterial, osteogenic, and self-healing properties

Magnesium implants show great promise for treating bone disorders, yet face challenges of rapid corrosion and inadequate biological functionality. The in-situ grown ZIF-8 coating enhances corrosion resistance of magnesium implants by improving interfacial adhesion while achieving biocompatibility and antibacterial activity through Zn 2+ release. Meanwhile, defects on the surface of graphene oxide (GO) adsorb Zn 2+ , triggering the heteroepitaxial growth of ZIF-8 nanoparticles. In this study, a composite coating of GO-doped layered double hydroxides (LDHs) on magnesium alloy micro-arc oxidation (MAO) coating surface was used as the substrate, with zinc phytate (Zn-IP6) as the zinc source, successfully inducing the in situ growth of ZIF-8 coating (ZP/GLDHs coating). The self-healing ZP/GLDHs coating markedly promoted adhesion, spreading, and proliferation of L929 fibroblasts and osteoblasts on its surface. In photothermal antibacterial assays against Staphylococcus aureus ( S. aureus ) and Escherichia coli ( E. coli ), it achieved 98.5% and 94.4% bacterial reduction, respectively. This study presents a novel strategy for the design of multifunctional magnesium implants that integrate antibacterial, osteogenic, and self-healing capabilities.