Carbon dot crosslinked hydrogel with microenvironment modulation for wound healing via synergistic antibacterial,...

The development of wound dressings that synergistically hemostasis, anti-bacterial, anti-inflammatory, and hypoxia mitigation remains challenging. Herein, a multifunctional hydrogel dressing (DCCG) was fabricated using dextran-derived aldehyde-rich carbon dots (Dex-CDs) and Cu^2 + to crosslink with carboxymethyl chitosan (CMCS) via Schiff base reaction and metal coordination interactions. The DCCG hydrogel with pH/NIR responsive allowed controlled release CDs and Cu²⁺ to eliminate bacteria and destruct biofilms. Moreover, the DCCG hydrogel significantly promoted fibroblast migration, angiogenesis, and collagen deposition to accelerate wound healing. These beneficial effects can be attributed to the regulation of the local microenvironment: CDs efficiently scavenged reactive oxygen species (ROS) to alleviate oxidative stress, Cu²⁺ facilitated oxygen generation to relieve hypoxia and promote neovascularization, thus inducing polarization of macrophages toward the pro-regenerative M2 phenotype to facilitate regeneration. This work offers a multifunctional and promising platform for next-generation intelligent wound management.