Carbon Dot-Capped Silver Nanoparticle-Embedded Double-Network Chitosan Hydrogel as a Multifunctional Biomaterial for Antibacterial, Hemostasis, and Wound Dressing

Bioinspired double-network (DN) hydrogels are generally considered superior to single-network hydrogels due to their ability to mimic the structure and mechanical behavior of tissues. Using DN hydrogels eventually overcomes the key limitations of single-network hydrogels, such as insufficient mechanical strength, poor adhesion, self-healing, and suboptimal biocompatibility. The fundamental aim of our work is to integrate well-characterized multifunctional materials into a single DN hydrogel to support diverse biomedical uses. Therefore, we have developed a double-network (DN) hydrogel, CG_CasK@CDs_AgNp, by incorporating carbon dot-capped silver nanoparticles (CasK@CDs_AgNp) into an acrylic acid hydrogel cross-linked with hydrocaffeic acid-modified chitosan via a polymerization reaction. The functionalization of hydrocaffeic acid endows higher adhesive strength. Carbon dot-capped silver nanoparticles induce additional physical cross-linking, antibacterial properties, and self-healing behavior of the matrix. CasK@CDs_AgNp exhibited minimum inhibitory concentrations (MICs) against E. coli and S. aureus of 8 μg/mL and 16 μg/mL, respectively. The synthesized hydrogels, CG_CasK@CDs_AgNp, exhibited excellent stretchability, viscoelastic nature, and good adhesive properties against human and pig skin. A time-kill study has demonstrated that CG_CasK@CDs_AgNp exhibits bactericidal activity within 9 h, achieving maximum killing, excellent hemostatic activity, promoting wound healing, and good cytocompatibility. Given its admirable antibacterial activity and good physicochemical nature, broad application in bacterial wound infections can be anticipated.