Additive manufacturing of biodegradable magnesium-based materials: Design strategies, properties, and biomedical applications

Magnesium (Mg)-based materials are a new generation of alloys with the exclusive ability to be biodegradable within the human/animal body. In addition to biodegradability, their inherent biocompatibility and similar-to-bone density make Mg-based alloys good candidates for fabricating surgical bioimplants for use in orthopedic and traumatology treatments. To this end, nowadays additive manufacturing (AM) along with three-dimensional (3D) printing represents a promising manufacturing technique as it allows for the integration of bioimplant design and manufacturing processes specific to given applications. Meanwhile, this technique also faces many new challenges associated with the properties of Mg-based alloys, including high chemical reactivity, potential for combustion, and low vaporization temperature. In this review article, various AM processes to fabricate biomedical implants from Mg-based alloys, along with their metallic microstructure, mechanical properties, biodegradability, biocompatibility, and antibacterial properties, as well as various post-AM treatments were critically reviewed. Also, the challenges and issues involved in AM processes from the perspectives of bioimplant design, properties, and applications were identified; the possibilities and potential scope of the Mg-based scaffolds/implants are discussed and highlighted.