Biodegradable shape-memory poly(ε-caprolactone)/polyhedral oligomeric silsequioxane nanocomposites: sustained drug release and hydrolytic degradation

Biodegradable shape-memory poly(ε-caprolactone) (PCL)/trisilanolphenyl polyhedral oligomeric silsequioxane (TspPOSS) nanocomposite films loaded with drug (theophylline) were prepared by a solution blending followed by solvent casting method. PCL/TspPOSS nanocomposite (90 wt/10 wt) loaded with 10 wt% drug exhibited fairly good thermally-triggered shape memory behavior with a shape fixity ratio of 81% and shape recovery ratio of 85%. In vitro drug release studies in the phosphate buffer solution (PBS; pH=7.4) revealed that the TspPOSS nanocrystals caused sustained release of the drug for the nanocomposites. It was also shown that TspPOSS enhanced the hydrolytic degradation rate of the PCL matrix.