Development of a natural small molecules composite based photothermal-responsive hydrogel dressing system for infected diabetic wound healing

Given the challenges posed by persistent bleeding, easy bacterial infections, high oxidative stress, and vascular damage within diabetic wounds, it is highly necessary to develop multifunctional wound dressings for wound healing in diabetic patients. Here, a injectable hydrogel wound dressing was developed by self-assembling chlorogenic acid (CA) and tobramycin (TOB) to chelate Fe³⁺ with the catechol part of the bioactive complex in Gelatin methacrylate (GelMA). The Fe-CA-TOB/GelMA integrated photothermal, antibacterial, and antioxidant functions. The resulting Fe-CA-TOB/GelMA hydrogel demonstrated sterilization efficacy of 99% against S. aureus and 95% against E. coli. The Fe-CA-TOB/GelMA also exhibited enhanced antioxidant capabilities. Notably, the Fe-CA-TOB/GelMA hydrogels were also capable of sustaining the release of both CA and TOB. The Fe-CA-TOB/GelMA hydrogels can also maintain a moist wound environment to facilitate re-epithelialization by eradicating bacteria, reducing excess reactive oxygen species (ROS), promoting macrophage polarization, and enhancing angiogenesis. This study introduces a novel approach for the incorporation of self-assembled bioactive complexes into hydrogels for the treatment of diabetic infected wounds, potentially advancing the application of high-performance hydrogels in biomedical contexts.