Low-drug resistance carbon quantum dots decorated injectable self-healing hydrogel with potent antibiofilm property and cutaneous wound healing

Local bacterial infection remains an increasingly severe threat to human health worldwide, and infection control is still a challenging task in clinics. Systemic administration of antibiotics usually causes adverse effects and bacterial resistance. Multi-functions hydrogel without drug-resistance is highly desired. Herein, we first synthesize antibacterial carbon quantum dots (CQDAG) with low-drug resistance using gentamicin sulfate and diammonium citrate as precursors. Then carboxymethyl chitosan (CMCS)-mixed CQDAG is reacted with oxidized dextran (ODex) through the Schiff base linkage to yield hydrogel network. Hydrogel decorated with 2 mg/mL CQDAG (CQDAG2-hydrogel) shows multi-functions including inherent self-healing, injectable, stretchable, compressive property, pH-dependent release of CQDAG and especially inhibiting biofilm formation, which are beneficial for treating bacterial infections. Besides, it is important that CQDAG2-hydrogel exhibits good cytocompatibility while sterilizing. In vivo antibacterial and wound healing evaluations demonstrate CQDAG2-hydrogel have the effect of anti-inflammation and promoting wound repair, which is manifested in wound healing rate, granulation tissue thickness and collagen disposition. The result indicates that the CQDAG2-hydrogel is excellent candidate for full-thickness skin wound healing.