Mechanical performance and biocompatibility assessment of Zn-0.05wt%Mg-(0.5, 1 wt%) Ag alloys.

Zn alloys are emerging as promising degradable biomedical materials due to their tailorable mechanical properties and moderate biodegradable rate, compared with conventional biodegradable metallic materials. Ag, as an effective antibacterial and reinforcing element, was incorporated into Zn-0.05Mg alloys. In the present work, the effects of the Ag addition on mechanical, cytotoxic, hemolytic, pyrogenic, histological behaviors of the animal were investigated. The compressive yielding strength is enhanced from 198 MPa for Zn-0.05Mg alloy up to 224 and 234 MPa for Zn-0.05Mg-0.5Ag and Zn-0.05Mg-1Ag alloys, respectively. When the compressive strain was 65%, the strength of the Zn-0.05Mg-1.0Ag alloy reached 833 MPa, which was much higher than that of 721 MPa for Zn-0.05Mg alloy. The relative growth rate (RGR) for the extracts of Zn-0.05Mg-1Ag alloy with the concentrations of 10, 50, and 100% after 5 days incubation reaches 98.5, 95.2, and 94.2%, which are higher than those in extracts of Zn-0.05Mg-0.5Ag alloy (98.2, 93.9, 92.1%). The hemolysis rate of the Zn-0.05Mg alloys with 0.5 and 1 wt% Ag is 2.46 and 2.28%, respectively. The variations of body weight and temperature, postinjection symptoms, pathological morphologies of the visceral organs demonstrate that the alloys are nontoxic according to the toxicity rating standards. Zn-0.05wt%Mg-(0.5, 1 wt%) Ag alloys are experimentally safe materials and promising for the future application as biodegradable medical devices.