(1. Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China) (2. BioMedX Center, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China)
Since the beginning of the 21st century, biodegradable metals have become a hot spot in the field of metallic biomaterials. Magnesium and its alloys are representative biodegradable metals that have been studied over the past decade. According to the search results of Web of Science, more than three thousand SCI articles have been published on the basic research work in the past ten years. With depthunderstanding of interaction mechanisms between degradable magnesium alloys and mechanics, chemistry and biology of host, some basic scientific problems have been preliminarily studied, such as “the composition design and performance optimization of biomedical magnesium alloys”, “the degradation mechanism of magnesium alloy in vivo and its regulation methods”, “the biosafety and metabolic pathways of degradation product of magnesium alloys” and “the degeneration of mechanical properties during the degradation process of magnesium alloys”, etc. Although a large number of magnesium alloys have been designed and studied for biomedical applications, they did not seem to be satisfactory for the medical device companies. Until now, there are only two magnesium alloys used as implanted medical devices that marketed worldwide—the WE43 series alloy from Germany, and Mg-Zn-Ca alloys from South Korea. Currently two products that have entered the innovative medical device in China are made of high purity magnesium. Therefore, in this paper, the preliminary screening of elements which are suitable for degradable metals in the periodic table are made by dual criteria: biodegradability and biocompatibility. On this basis, the promising alloying elements for biomedical magnesium alloys are proposed. It is supposed to provide a new direction for the material design of future medical magnesium alloys from a different perspective, with better biosafety and biofunction.