A novel biodegradable Mg-1Zn-0.5Sn alloy: Mechanical properties, corrosion behavior, biocompatibility, and antibacterial activity

To meet the growing demand for antibacterial implants for bone-implant-associated infection therapy and avoid the adverse effects of secondary surgery, a degradable platform with pH responsiveness and ion-associated antibacterial properties was constructed. A small amount of Sn added to Mg-1Zn alloy reduces the biocorrosion rate, which can be attributed to Sn participation in outer-layer film formation, significantly reducing the biocorrosion rate and hydrogen evolution rate after implantation in vivo. These Mg alloys, which are susceptible to degradation in the acidic bacterial microenvironment, degrade by releasing Mg, Zn and Sn, producing favorably alkaline and antibacterial conditions. Samples with the composition of Mg-1Zn-0.5Sn were found to be beneficial for promoting initial cell adhesion and proliferation, resulting in improved biocompatibility and biosafety. The biocompatibility of this alloy was confirmed by the healthy behavior of animals and the absence of acute or chronic toxicity in the liver, spleen, and kidneys. Our results demonstrate that Mg-1Zn-0.5Sn is safe for biological systems, enabling its efficacious use in biomedical applications. (C) 2020 Published by Elsevier B.V. on behalf of Chongqing University.