A multi-responsive self-healing hydrogel for controlled release of curcumin†

Curcumin is a traditional herbal medicine with immense therapeutic potential; however, its application is severely limited owing to its poor water solubility. In this study, a multi-responsive self-healing hydrogel for the controlled release of curcumin was developed using dynamic boronic acid ester linkages. A phenylboronic acid-containing polymer was used to conjugate curcumin and generate hydrogels using poly(vinyl alcohol). The synthesized curcumin-loaded hydrogels were self-healing owing to the dynamic nature of the borate linkages; the rate of curcumin release could be modified using multiple stimuli, which resulted in shifting of the equilibrium between borate and boronic acid. The hydrogels were biocompatible and were successfully used to prompt the healing of cell-layer wounds. Our findings provide a novel approach to improve the bioavailability of curcumin using dynamic borate linkages, which may prompt further studies on curcumin and in-depth investigations into the dynamic linkages in the field of polymer chemistry and biomaterials.