A mussel-inspired hydrogel matrix with photothermal activity and phycocyanin-modified cerium oxide nanoparticles with antioxidant activity for synergistic infected wound healing.

The ability of hydrogels to promote wound healing has been extensively studied. Developing multifunctional hydrogel dressings to address the complex microenvironment of infected wounds remains a significant challenge and focus in current research. Herein, inspired by adhesion chemistry, we constructed a multifunctional composite hydrogel (GelDA/OPL) with excellent adhesion, self-healing properties, injectability, and photothermal antibacterial activity through Schiff base crosslinking between dopamine-modified gelatin (GelDA) and oxidized pullulan (OPL). By varying the concentration of OPL, the mechanical and rheological properties of GelDA/OPL can be appropriately adjusted. Furthermore, by introducing phycocyanin-modified CeO2@PC NPs, we endowed GelDA/OPL with remarkable antioxidant characteristics capable of rapidly scavenging ˙OH, ABTS˙+, and DPPH˙ radicals. The results indicate that the incorporation of catechol groups not only enhanced the adhesive performance of GelDA/OPL/CeO2@PC hydrogels but also imparted exceptional photothermal conversion efficiency under 808 nm laser irradiation, effectively inhibiting Staphylococcus aureus and Escherichia coli. The applicability of GelDA/OPL/CeO2@PC hydrogels in promoting wound healing in vivo was further validated using a full-thickness skin defect infection model in rats. Overall, the prepared GelDA/OPL/CeO2@PC hydrogel represents a promising multifunctional wound dressing that contributes to accelerating the healing process for infected wounds.