Current Advances in the Roles of Doped Bioactive Metal in Biodegradable Polymer Composite Scaffolds for Bone Repair: A Mini Review

The election of bone tissue engineering scaffolds material is mainly based on the bionics of natural bones. Although the content of trace elements in bone is low, the lack of them affects the growth and metabolism of bones, thus increasing the risk of orthopedic diseases caused by the deterioration of bone quality. Therefore, inspired by trace elements in natural bone, biodegradable polymer composite scaffolds doped with bioactive metals such as Mg, Zn, Sr, Fe, Cu, Mn, Co, Li, Ag, Nb, and V have attracted more attention. Herein, the role of bioactive metals doping in biodegradable polymer matrix is mainly reviewed, including improving hydrophilicity, preventing aseptic inflammation caused by acidic degradation products, imparting antibacterial activity, improving mechanical properties, and promoting vascularization of polymer scaffolds. Then, the reasons and solutions for interfacial bonding and cytotoxicity caused by doping bioactive metals are focused on. Bioactive metals are incorporated into a biodegradable polymer bone scaffold. It can not only improve the ability of promoting osteogenic differentiation, but also the hydrophilicity, aseptic inflammation, antibacterial properties, mechanical properties, and vascularization ability of scaffolds. The interfacial bonding and cytotoxicity caused by the introduction of metal components are also discussed.