Effect of acidic degradation products of poly(lactic-co-glycolic)acid on the apatite-forming ability of poly(lactic-co-glycolic)acid-siloxane nanohybrid material

The effect of poly(lactic-co-glycolic) acid (PLGA) degradation products on the apatite-forming ability of a PLGA-siloxane nanohybrid material were investigated. Two PLGA copolymer compositions with low and high degradability were used in the experiment. The PLGA-siloxane nanohybrid materials were synthesized by end-capping PLGA with acid end-groups using 3-isocyanatopropyl triethoxysilane following the sol-gel reaction with calcium nitrate tetrahydrate. Two nanohybrid materials that had different degradability were exposed to simulated body fluid (SBF) for 1-28 days at 36.5°C. The low degradable PLGA hybrid showed apatite-forming ability within 3 days of incubation while the high degradable one did not within 28 days testing period. The results were explained in terms of the acidity of the PLGA degradation products, which could directly influence on the apatite dissolution.