Multifunctional carbon quantum dots decorated self-healing hydrogel for highly effective treatment of superbug infected wounds

Rapid healing of wounds infected by bacteria, especially multidrug-resistant bacteria, is a common clinical challenge. Local bacterial infection causes excessive reactive oxygen species (ROS) that further induce oxidative stress and inflammatory responses, which impairs cell migration, angiogenesis and delays cutaneous regeneration. Herein, we designed a novel type of carbon quantum dots (CQDs) derived from herbal medicines. The CQDs are able to against gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA), and possessed SOD-like as well as CAT-like activities for scavenging ROS. The biocompatible CQDs could protect HUVECs migration and angiogenesis from oxidative stress damage. Moreover, the expression of NO and pro-inflammatory cytokines (TNF-α and IL-6) of LPS-induced macrophages could be downregulated by the CQDs. Besides, the self-healing hydrogel decorated with multifunctional CQDs were prepared via the reaction between OSA and CMCS through Schiff base linkage for better wound management. The CQDs/hydrogel could continuously eliminate bacteria and scavenge ROS to modulate the complex oxidative stress microenvironment. The results of animal experiments demonstrated that the CQDs/hydrogel exerted the effects of eliminating MRSA, anti-inflammation, and promoting angiogenesis, which was manifested in enhancing wound healing, epithelial regeneration and collagen disposition. Therefore, the CQDs/hydrogel is excellent candidate for MRSA-infected skin wound healing.