Developing antibacterial Zn-Cu-Mg alloys with high strength and osteogenic stimulation for osteomyelitis

Biodegradable metals are promising candidates for osteomyelitis management because they can provide mechanical support, enable tunable degradation, display inherent antibacterial effects, and stimulate osteogenesis. Here, Zn alloys incorporating Cu and Mg were designed as multifunctional implant materials to concurrently suppress infection and promote bone regeneration. Equal channel angular pressing (ECAP) was used to refine grains to the submicron scale and substantially fragment secondary phases. Mechanical testing showed that Zn-1Cu-1Mg alloy achieved the highest hardness and tensile strength among the investigated alloys, which is attributed to the combined contributions of grain refinement and second-phase strengthening. Electrochemical and immersion evaluations further indicated that the addition of Cu improved corrosion resistance of Zn-1Mg alloy. The reduced corrosion rate is associated with the formation of compact corrosion layers enriched in Zn, O, C, Ca, P, and Cl. In vitro assays using BMSCs demonstrated high cell viability, meanwhile, osteogenic assessments revealed enhanced ALP activity, increased mineralized nodule formation, and upregulated osteogenic gene expression. All Zn alloys also showed pronounced antibacterial activity against S. aureus and E. coli. Collectively, these results suggest that Zn-1Cu-1Mg alloys offer a multifunctional biodegradable option for osteomyelitis through the integration of infection control and bone regeneration.