Abstract
The incorporation of molecular switches into polymer networks has been a powerful approach for the development of functional poly-mer materials that display macroscopic actuation and function enabled directly by molecular changes.However,such materials sometimes re-quire harsh conditions to perform their functions,and the design of new molecular photoswitches that can function under physiological condi-tions is highly needed.Here,we report the design and synthesis of a spiropyridine-based photoswitchable hydrogel that exhibits light-driven ac-tuation at physiological pH.Owing to its high pKa,spiropyridine maintains its ring-open protonated form at neutral pH,and the resulting hydro-gel remains in a swollen state.Upon irradiation with visible light,the ring closure of spiropyridine leads to a decrease in the charge and a reduc-tion in the volume of the hydrogel.The contracted gel could spontaneously recover to its expanding state in the dark,and this process is highly dynamic and reversible when the light is switched on and off.Furthermore,the hydrogel shows switchable fluorescence in response to visible light.Bending deformation is observed in the hydrogel thin films upon irradiation from one side.Importantly,the independence of this spiropyri-dine hydrogel from the acidic environment makes it biotolerant and shows excellent biocompatibility.This biocompatible spiropyridine hydro-gel might have important biorelated applications in the future.
基金项目
National Natural Science Foundation of China(52373121)
National Key R&D Program of China(2022YFA1305100)
Natural Science Foundation of Anhui Province(2208085MB27)
维普
万方数据