Structure And Corrosion Resistance Of NHA/PLGA/Mg Biocomposites

Magnesium as a new material with suitable mechanical strength and elasticmodulus. It can withstand a certain pressure, and it can avoid the stress shieldingeffect; magnesium percesses biocompatible biodegradable; magnesium can promotebone healing. So magnesium alloy as bone graft in the repair of oral mandibulardefects has great potential.However, magnesium has rapid degradation of magnesiumin the body.So it can not play a good part in supporting bone tissuedefects.Therefore,the present experiment studied nHA and PLGA on magnesium withalloying and surface modification method,geting a new bio-composite material inorder to improve the internal structure and corrosion resistance of magnesium,andslow down the rate of degradation of magnesium.In this experiment,we mixed nano-hydroxyapatite into magnesium powder toprepare nHA/Mg alloy by powder metallurgy method.The PLGA and nHA whichwere dissolved in chloroform were used to prepare PLGA and nHA/PLGA coatingswith dipping pulling method.By means of SEM we analysisd the surface morphologyof composites and morphology after etching patterns.Then we studied the relationshipbetween the degradation rate and time,and explored the pH value of the compositevariation in the corroding solution.NHA/Mg alloys obtained by powder metallurgy method have idealorganizational structure.Coatings obtained by dipping pulling method have roughsurface,uniform thickness,and no obvious cracks and other holes.With increasing thenumber of coating, thickness and quality of coating increased.There is a positiverelationship between them.Static corrosion tests showed that the coating canefficiently slow down the corrosion rate of the composite materials,extend theresidence time in the body,reduce the PH value of the etchant materials and improvethe biocompatibility of the composite. NHA/PLGA/Mg biocomposite materialobtained by this experiment has reasonable space structure, favorable biocompatibilityand biodegradability.The degradation products can be fully absorbed by the body.It isa safe and pollution-free materials.The experimental results provides a theoreticalbasis and experimental basis for the clinical application of magnesium alloy onmandibular defect repair.NHA/PLGA/Mg biocomposite material has good prospectsfor clinical application.