Hydrogel redox-responsive degradation: rheological experiments were carried out to demonstrate the disassociation of the gel matrix in the presence of a reducing agent. 17 and the amount of API released in the supernatant was determined using a UV-vis spectrophotometer at 495 nm and 280 nm for FITC-BSA and vancomycin respectively. For the on-demand release study, hydrogels were treated with 100 mM GSH and 100 mM DTT after 3 h of passive release. The release experiment was repeated 3 times for each set of hydrogels.