PNNL

Abstract

Here we report the design of injectable and thermosensitive hydrogel composites comprised of poly(lactic acid-co-glycolic acid)-g-poly(ethylene glycol)(PLGA-g-PEG) containing hydroxyapatite (HA) for potential application in bone tissue engineering. Inclusion of HA into the hydrogels would provide both enhanced mechanical strength and bioactivity to the composites. The effects of HA on the properties of the hydrogels were investigated in terms of mechanical strength, sol-gel transition properties, pH, and in vitro dye release behavior. The results revealed that hydrogel composites preserved their sol-gel transition properties in the presence of HA. The maximum mechanical strength of the hydrogels was enhanced in a HA-content dependent manner, and the acidic pH environment of the hydrogel was neutralized by HA. Furthermore, the presence of HA had little influence on the model dye release kinetics from the hydrogels. The current hydrogel composites showed a sustained release of a small molecular weight dye model for up to 2 weeks and thus may find application in drug delivery for bone tissue engineering.