Injectable biomimetic hydrogels encapsulating Gold/metal–organic frameworks nanocomposites for enhanced antibacterial and wound healing activity under visible light actuation

Abstract

• Biomimetic injectable hydrogel embedded with Au/MOF composites was synthesized. • Au nanoparticles could improve visible light-driven photocatalysis of ZIF-8. • The hydrogel kills bacteria under visible light while promoting wound healing. Antibiotic resistance of bacteria is one of the greatest threats to wound healing, which necessitates the need for alternative strategies to eradicate bacteria in the wound site. Taking advantage of the reactive oxygen species (ROS)-generating capability of photocatalytic semiconductor nanomaterials under light irradiation, here we report a biomimetic injectable double-network hydrogel using oxidized sodium alginate and carbohydrazide-modified methacrylated gelatin that mimics the extracellular matrix, which was further embedded with semiconductor-like metal–organic frameworks (MOFs) encapsulating noble metal nanoparticles (Au@ZIF-8). This composite design substantially improved the ROS generation under visible light actuation (>400 nm) compared with pristine ZIF-8, owing to its reinforced light absorption and charge carrier separation by the Au-mediated surface plasmon resonance (SPR) and Schottky junction. The composite hydrogels not only showed remarkable bactericidal activity against both E. coli and S. aureus , but also significantly accelerated wound healing at optimal safety. Altogether, this injectable double-network hydrogel could simultaneously provide antibacterial and pro-healing capabilities, which may have translational potential as wound dressing materials.