A Biodegradable and Bioactive Composite Potentially for Orthopaedic Applications

摘要

Magnesium has shown potential to become a biodegradable implant material for orthopaedic applications. However, it degrades too fast in physiological solutions. Proper alloying can reduce its degradation rate but may introduce cytotoxic elements. Moreover, magnesium itself lacks bioactivity. It was hypothesized that adding bioactive agents to magnesium could induce the formation of a surface mineral layer that could protect it from fast degradation and enhance its surface bioactivity. A mixture of pure magnesium and bioactive glass powders was compacted, sintered and extruded. Full consolidation and uniform distribution of bioactive glass particles were achieved. EDX indicated the lack of interactions between the matrix and bioactive glass. Immersion tests in a cell culture medium showed weight gain, attributed to the formation of a mineralized layer containing O, Ca, P, Na, Si and Mg on composite surface. P/M was found to be a viable route to produce biocomposites with reduced degradation rate and enhanced bioactivity.