A novel biodegradable nanocrystalline Zn alloy with exceptional biocompatible and antibacterial properties

Abstract

The development of biodegradable Zn alloys with comprehensive performance for biomedical applications is still challenging. Hence, the nanocrystalline Zn–Cu–Sr–Li alloys were prepared by alloying design and multi-pass high-speed hot rolling. The Zn–3Cu-0.2Sr-0.4Li alloy achieved nanoscale microstructures, resulting in high strength and an ideal corrosion rate that is more suitable for tissue repair cycles. Scanning Kelvin probe force microscopy analysis revealed the potential from high to low was ranked as: ε phase > SrZn13 phase > Zn grains > β phase. The nanoscale Zn grains and β particles formed numerous microcells, enhancing the microgalvanic corrosion effect. The Sr ions could be released more efficiently during the degradation in Li-containing alloys, which endowed the alloys with outstanding biocompatibility. Besides, the synergistic release of Zn ions and Cu ions during alloy degradation endowed the alloy with excellent antimicrobial ability against Staphylococcus aureus (inhibition zone diameter ≈ 7.5 mm). The antimicrobial ability of Zn–3Cu–0.2Sr–0.4Li alloy was superior among the reported biodegradable Zn alloys. These results demonstrated nanocrystalline Zn–Cu–Sr–Li alloys have comprehensive performance and broad application prospects in biodegradable bone implants, providing the experimental and theoretical basis for future research in the biomedical field.