In the past decades, metals have been considered as promising materials in the fields of regenerative medicine and tissue engineering. Metallic bio-materials with excellent mechanical strength can effectively support and replace damaged tissue. Hence, metals have been widely used in load-bearing applications for dentistry and orthopedics. cobalt-, iron-, and titanium (Ti)-based alloys are representative bio-metals used in various forms such as vascular stents, hip joints, dental, and orthopedic implants. However, the alloying elements of Co-and Fe-based alloys, Co, Ni, and Cr, induce severe toxicity when ionized in the body, which limits their clinical use.