The effect of the type of HA on the degradation of PLGA/HA composites

Abstract The aim of this study is to explore the importance of the potentially competing effects of buffering effects of the calcium phosphate filler and particle-mediated water sorption on the degradation products of poly( d , l lactide- co -glycolide (50:50))(PLGA)/hydroxyapatite(HA) composites. Further the influence of type of HA on the mechanical properties of the composites was investigated. Phase pure HA was synthesised via a reaction between aqueous solutions of calcium hydroxide and orthophosphoric acid. The powder produced was either used as produced (uncalcined) or calcined in air or calcined in a humidified argon atmosphere. An in-vitro degradation study was carried out in phosphate buffered saline (PBS). The results obtained indicated that the degradation rate of the composite might be better understood if both the buffering effects and the rate of water sorption by the composites are considered.