Past, Present, and Future of Fe-Mg Bioresorbable Alloys for Medical Applications

The search for biocompatible and bioabsorbable metallic materials for temporary medical implants dates back to the late nineteenth century. Interest in these materials arises from their potential social and medical benefits. However, extensive research did not start until the early twentieth century, primarily focusing on magnesium (Mg), iron (Fe), and zinc (Zn) as biocompatible and biodegradable base metals. In this work, we explore the combination of two of these metals, Fe and Mg, and the opportunity to investigate Fe-Mg alloys as potential candidates for biomedical applications through a review of their development from their initial production to the present, as well as their future prospects. A distinctive characteristic of Fe-Mg systems is their mutual immiscibility in thermodynamic equilibrium, which poses significant processing challenges and explains why Fe-Mg alloys have been relatively unexplored. However, it is precisely this immiscibility that offers the opportunity to achieve a metastable state that potentiates degradation. As evidenced by the review of recent research on bioabsorbable Fe-Mg alloys developed specifically for biomedical applications, given their promising properties and potential applications, a more comprehensive exploration of this alloy system appears warranted.