Silk fibroin loaded carbon point-chlorogenic acid complex hydrogel for photothermal/antioxidant therapy of diabetic wound.

Diabetic wound healing poses a significant clinical challenge, primarily due to bacterial infection and persistent inflammation mediated by excessive reactive oxygen species (ROS). To address this issue, we developed a nanocomposite named Carbon quantum dot-chlorogenic acid (CD-C), which integrates synergistic antibacterial and antioxidant functionalities to promote diabetic wound healing. CD were synthesized via a facile method using cost-effective precursors, citric acid and urea, and subsequently combined with chlorogenic acid to form a nanocomposite system capable of simultaneous photothermal sterilization and ROS scavenging. The as-prepared CD exhibited a particle size distribution of 2-10 nm, while CD-C showed an average size between 150 and 250 nm. Furthermore, CD-C demonstrated remarkable photothermal performance, with an impressive conversion efficiency of 40.65 %. At a concentration of 150 μg/mL, CD-C displayed broad-spectrum antibacterial activity against two typical drug-resistant bacterial strains, achieving an inhibition rate exceeding 98 %. It also effectively disrupted bacterial biofilms. Concurrently, CD-C efficiently scavenged ROS, mitigating oxidative stress-induced cellular damage. To enhance its applicability, CD-C was incorporated into a silk fibroin (SF) hydrogel, forming a CD-C@SF composite dressing. This system significantly accelerated diabetic wound healing through combined antibacterial, antioxidant, and anti-inflammatory effects. Animal experiments revealed that nearly complete wound closure was achieved within 10 days following treatment with CD-C@SF. This study not only highlights the promise of integrated nanomaterial platforms for diabetic wound management but also underscores the potential of carbon quantum dot-based composites as an effective biomedical strategy.