Correspondence

Biodegradable-polymer stents versus durable-polymer stents – Authors' reply

With a suitable degradation rate, fully bioresorbable degradation products, and excellent biocompatibility, Zn and its alloys are regarded as the most promising biodegradable metallic materials for clinical applications. However, their strength and ductility are generally below the mechanical benchmark for biodegradable implants, such as bone fixtures and stents, which restrict wider applications. Over the past decade, enormous efforts have been dedicated to improving the mechanical performance of Zn alloys, which greatly advance our understanding of Zn alloy development. This review highlights recent progress of biodegradable Zn alloys from the perspective of strengthening and toughening, with an emphasis on the relationship between the microstructure and the mechanical properties of the four major Zn alloy systems: Zn–Mg, Zn–Li, Zn–Mn, and Zn–Cu based alloys. The dominant mechanisms for high strength and high ductility of these alloys are elaborated. Finally, the future challenges and research directions of the field are outlined. This review strives for provide guidance for the future development of high-performance bioresorbable Zn alloys.