A biodegradable in situ Zn-Mg2Ge composite for bone-implant applications

Zinc (Zn)-based composites have received extensive attention as promising biodegradable materials due to their unique combination of moderate biodegradability, biocompatibility, and functionality. Nevertheless, the low mechanical strength of as-cast Zn-based composites impedes their practical clinical application. Here we reported the mechanical properties, corrosion behavior, wear properties, and cytotoxicity of in situ synthesized biodegradable Zn-xMg 2 Ge ( x = 1, 3, and 5 wt.%) composites for bone-implant applications. The mechanical properties of Zn-xMg 2 Ge composites were effectively improved by alloying and hot-rolling due to particle reinforcement of the Mg 2 Ge intermetallic phase and dynamic recrystallization. The hot-rolled (HR) Zn-3Mg 2 Ge composite exhibited the best mechanical properties, including a yield strength of 162.3 MPa, an ultimate tensile strength of 264.3 MPa, an elongation of 10.9%, and a Brinell hardness of 83.9 HB. With an increase in Mg 2 Ge content, the corrosion and degradation rates of the HR Zn-xMg 2 Ge composites gradually increased, while their wear rate decreased and then increased in Hanks' solution. The diluted extract (12.5% concentration) of the HR Zn-3Mg 2 Ge composite showed the highest cell viability compared to the other HR composites and their as-cast pure Zn counterparts. Overall, the HR Zn-3Mg 2 Ge composite can be considered a promising biodegradable Zn-based composite for bone-implant applications.

Automated summary

This study investigates the mechanical properties, corrosion behavior, wear properties, and cytotoxicity of biodegradable Zn-xMg 2 Ge composites. The results show that the mechanical properties of the composites can be effectively improved by alloying and hot-rolling, with the Zn-3Mg 2 Ge composite exhibiting the best performance. However, an increase in Mg 2 Ge content leads to higher corrosion and degradation rates.