Light-Triggered Cross-Linking of Linear Poly(ethylene glycol) Hydrogels for Enhanced Antibacterial Delivery

Due to the limited functional groups on poly(ethylene glycol) (PEG) terminals, hydrogels are usually prepared by PEG chains with multiple arms. It is challenging for the preparation of hydrogels using linear PEG. Herein, we report the light-triggered synthesis of hydrogels composed of linear PEG with bis-maleimide groups. In the presence of a photoinduced catalyst, the α-C-H bonds on the PEG chain are cleaved, allowing the maleimide groups to be incorporated into the main chain, forming a cross-linked structure. The cleavage of the unstable C-O bonds could result in degradation of hydrogels. The release of encapsulated tobramycin from degradable hydrogels shows better antibacterial properties compared to undegradable hydrogels, which results in highly effective antimicrobials at the wound site. This work presents a method for the preparation of degradable hydrogels using linear PEG as a component for biological applications.