Challenges and opportunities for biodegradable magnesium alloy implants

Abstract

Magnesium (Mg) and its alloys posse’s great potential for the application of biodegradable medical implants. It is due to their unique properties like low density and elastic modulus, good biocompatibility, etc. But still there are many challenges for Mg alloy based implants. Due to rapid degradation of Mg and its alloys in biological fluid, it loses its mechanical integrity and fails to perform before the complete healing of bone fracture (in orthopedics application) or removal of plaque in arteries (in case of vascular implants). Using suitable alloying elements mechanical strength and corrosion resistance of Mg-alloys can be enhanced but cytotoxicity and long term inflammatory consequences of these elements are the major concern. Further modifying the surface characteristics of Mg-alloy through various surface coating, machining, mechanical working, etc., corrosion behaviour can be manipulated. In this field of biodegradable implants, the various opportunities are yet to be explored in detail to improve the clinical performance of Mg alloy implants for orthopedics and vascular applications. This review paper summarises the various challenges and opportunities in design and development of biodegradable Mg alloy implants.