Preparation and property of coating on degradable Mg implant

To be an implant material,it is necessary to have good corrosion resistance for magnesium and magnesium alloy in the period of tissue healing process.To improve corrosion resistance of pure magnesium,dipping technology was employed in the present work to prepare the poly(lactic acid) coating on Mg implant.Different molecular mass poly(lactic acid) and a surface pretreatment technology applying silane coupling agents on Mg implant was used to improve adhesion strength between Mg implant and poly lactic acid.Scanning electron microscopy(SEM) was used to gain the effect of dipping time,polymer concentration and dipping times for the thickness of coating.The results show that poly(DL-lactide-co-glycolide)(PLGA) with relative molecular mass of 200 thousand can meet the need of degradation condition and strength adhesion of biodegradable implant.The mass loss of PLGA film coated Mg implant is decreased obviously after they are immersed in Hank’s solution.It can be concluded that PLGA coating can effectively protect magnesium from corrosion in simulation biology solution.