Chlorella-embedded hydrogel wound dressing based on carboxymethyl chitosan and κ-carrageenan with oxygen production and antibacterial activity for wound healing.

Hypoxia and bacterial infection synergistically impede skin wound healing, posing significant clinical challenges. Conventional oxygen-releasing agents and antimicrobial agents are constrained by poor biocompatibility and the emergence of drug resistance. Consequently, the development of biocompatible, non-resistance-inducing oxygen-releasing antimicrobial wound dressings is of paramount importance. This study presents a κ-carrageenan (κ-Cr)/carboxymethyl chitosan (CMCS) hydrogel wound dressing loaded with Chlorella and berberine (BBR). Chlorella facilitates stable and sustained oxygen release with excellent biocompatibility, while berberine exhibits broad-spectrum antimicrobial activity without inducing drug resistance. In vitro experiments reveal that under light conditions, the hydrogel releases a cumulative 8 mg/mL of oxygen within 8 h and reduces bacterial viability to 2%, demonstrating excellent sustained oxygen-release and antimicrobial properties. The hydrogel matrix, formed via electrostatic cross-linking of κ-carrageenan and carboxymethyl chitosan, enhances adhesive performance, endowing the dressing with outstanding mechanical properties and skin adhesiveness. In vivo studies using a rat full-thickness skin wound model demonstrate the hydrogel's remarkable wound-healing efficacy: the wound healing rate reaches 98% by day 10, highlighting the hydrogel's ability to accelerate wound repair. Overall, this multifunctional hydrogel wound dressing holds substantial promise in the field of skin wound healing and provides a promising therapeutic strategy for patients with complex healing needs.