Degradable Biomaterials for Temporary Medical Implants

Degradable biomaterials bring possibilities to fabricate medical implants that function for a determined period related to clinical events such as healing. They can be made on the basis of polymers, ceramics and metals. These metals, which are expected to corrode gradually in vivo with an appropriate host response and then dissolve completely upon fulfilling the mission to assist with tissue healing, are known as biodegradable metals. They constitute a novel class of bioactive biomaterials which supports the healing process of temporary clinical problems. Three classes of metals have been explored: magnesium-, zinc- and iron-based alloys. Three targeted applications are envisaged: orthopaedic, cardiovascular and pediatric implants. Three levels of investigations have been conducted: in vitro, in vivo and clinical trials. Discussion on standardization has been initiated since 2013 with representatives from ISO, DIN and ASTM and drafts of comprehensive standards are now under preparation. The field of biodegradable metals is exciting and witnessing more development in the future including new advanced alloys and new real breakthrough that leads to its clinical translation. This chapter starts with a discussion on biodegradable polymers to gain important lessons learned for advancing the research in biodegradable metals, the new emerging research interest in the forefront of biomaterials loaded with full of great expectations.