KCS

In recent decades, hydrogels have been extensively investigated as a model platform for drug delivery and controlled release due to their distinctive properties such as swollen controllable, biocompatible and bio-mimetic. Among the others, the environmental-adaptive hydrogels have received a great attention since they have been revealed to change their physiochemical properties and phase states rabidly and controllably toward the versatile stimulations. The photo-responsive hydrogel, which has been of a great interest among those environmental-adaptive hydrogels, has opened a new approach for studying drug delivery. Herein, we introduce a new hydrogel platform for drug delivery based on maleimide functionalized hyaluronic acid (HA-Mal), crosslinked by photo-dissociable dimeric Dronpa green fluorescence protein (pdDronpa). This hydrogel was formed by the Michael-type addition reaction, through the conjugation of maleimide groups bearing on HA chains with the free cysteine sites of pdDronpa. The results demonstrated that the pdDronpa-HA-Mal hydrogel was reversibly and rapidly switched its states between sol and gel upon 500 nm and 400 nm illumination, as a result of the photo-dissociation and re-association of pdDronpa between dimeric and monomeric forms. The response behaviors of the Dronpa-HA-Mal hydrogel to photo-stimulation were further evidenced by SEM imaging and rheological performs, indicating the disintegration and aggression of the crosslinked network of the hydrogel toward 500 nm and 400 nm illumination. Besides, the photo-controlled release of DNA was also investigated using this hydrogel platform, showing the release of DNA from the hydrogel can be simply controlled by adjusting the dose of pdDronpa and illuminations.