Biodegradable Metals: 

After decades of developing strategies to minimize the corrosion of metallic biomaterials, there is now an increasing interest to use corrodible metals in a number of medical device applications. The term “biodegradable metal” (BM) has been used worldwide to describe these new kinds of degradable metallic biomaterials for medical applications and there were many new findings reported over the last decade. The recently-developed representative Mg-based BMs (pure Mg, Mg–Ca alloy, Mg–Zn alloy, etc.), Fe-based BMs (pure Fe, Fe–Mn-based alloys, etc.) and other BMs (pure W, pure Zn and its alloys, Ca-based and Sr-based bulk metallic glasses, etc.) were comprehensively reviewed with emphases on their microstructures, mechanical properties and degradation behaviors, in vitro and in vivo performances, pre-clinical and clinical trials. Moreover, current approaches to control their biodegradation rates to match the healing rates of the host tissues with various surface modification techniques and novel structural designs. BM belongs to “bioactive” biomaterials and its future research and development direction should lean towards “third-generation biomedical materials” with “multifunctional capabilities” in a controllable manner to benefit the local tissue reconstruction.