UV-triggered thiol–disulfide exchange reaction towards tailored biodegradable hydrogels

We report a method of utilizing a UV-triggered thiol–disulfide exchange reaction for constructing biodegradable hydrogels with tailored properties from a water-soluble comb-like polymer of P(EMA-SS-PEG), a polyethylene glycol grafted poly(ethyl methacrylate) derivative with the disulfide linkage as the grafting point. This photochemical method provides precise spatiotemporal control over the structures and properties of disulfide-crosslinked hydrogels. By varying the irradiation time, we facilely adjust the crosslinking degree of hydrogels, thereby regulating their morphology, mechanical properties, hydrophilic properties, and swelling ratio. The photochemical method can easily fabricate macro-/micro-customized patterned hydrogels, indicating its precise spatial control on the photochemical gelation process. In addition, the tailor-made biodegradable hydrogels can achieve tunable absorption and release behaviors of RB dyes, proving their potential application in controlled drug delivery.