CONTROLLING THE BIODEGRADATION OF MAGNESIUM IMPLANTS THROUGH NANOSTRUCTURED COATINGS

摘要

Magnesium (Mg) alloys, a novel class of degradable, metallic biomaterials, have attracted growing interest as a promising alternative for medical implant and device applications due to their advantageous mechanical and biological properties. Moreover, magnesium is biodegradable in the physiological environments. The major obstacle for Mg to be used as medical implants is its rapid degradation in physiological fluids. Therefore, the present key challenge lies in controlling Mg degradation rate in the physiological environment. The objective of this study is to develop a nanostructured-hydroxyapatite (nHA) coating on Mg implants to control the degradation and bone tissue integration of the implants. Nanostructured-HA coatings are deposited on magnesium using the Spire's patented TPA process to moderate the aggressive degradation of magnesium and to improve fast osteointegration between magnesium and natural bone. Morphology and element compositions were characterized using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis. The degradation of nHA coated Mg and uncoated Mg was investigated by incubating samples in phosphate buffered saline (PBS) under standard cell culture conditions. The degradation results suggest the nanocoatings positively mediated magnesium degradation. Therefore, nHA coatings are promising for controlling the biodegradation of magnesium-based orthopedic implants and devices.