Figure 5.

Dual stimuli-responsive drug release hydrogel. Optical photographs (A) and schematic illustration for the self-gelation (B) of aqueous 1.0 wt% HA–DOX conjugate solution when exposed to the air at room temperature (23 °C), and (C) pH-triggered drug release profiles of HA–DOX conjugate hydrogel. The photographs (×5) and relative viabilities of human nasopharyngeal carcinoma CNE2 cells: (D) treated with the release media of HA–DOX conjugate hydrogel under various pH conditions without glutathione (GSH) and treated with the release media of HA–DOX conjugate hydrogel in the absence and presence of GSH (10 and 50 mmol/L) when the pH value was kept at 5.0. Individual PBS (pH 7.4) was used as the control. Reproduced from [109], copyright permission by Elsevier 2017.