Mussel-inspired adhesive carboxymethyl chitosan-based hydrogel with hemostatic and photothermal antimicrobial properties for rapid hemostasis and wound healing.

The development of wound dressings with hemostatic and antimicrobial properties has garnered considerable interest in biomedical research. In this study, adhesive hydrogels composed of carboxymethyl chitosan (CMC) and polydopamine (PDA) crosslinked with iron ions (Fe3+) were synthesized. Leveraging the intrinsic coagulant activity of Fe3+ as a crosslinking agent, the hydrogels were fabricated via in situ ligand polymerization of CMC and PDA. Firstly, structural characterization revealed the hydrogel formed through Fe3+-mediated coordination bonds, exhibiting robust physicochemical properties and strong adhesion. In addition, photothermal experiments under near-infrared (NIR) irradiation showed that the hydrogel had a high photothermal conversion efficiency (warming >30 °C) and could inhibit bacterial infection. Meanwhile, the CMC-Fe3+-PDA hydrogel also demonstrated notable antioxidant and immunomodulatory activities. In addition, adhering to the wound was more conducive to hemostasis (hemostasis time was 11 ± 3 s for the liver injury model and 10.6 ± 3 s for the tail injury model). Finally, experiments on a rat model of whole-layer skin defects showed that CMC-Fe3+-PDA hydrogel promoted the crawling of traumatized granulation tissues and accelerated wound repair. Immunofluorescence staining experiments showed that hydrogel enhanced angiogenesis by up-regulating the expression of CD31. Collectively, these results demonstrate that the CMC-Fe3+-PDA hydrogel exhibits desirable adhesion, hemostasis, antibacterial efficacy, antioxidant capacity, and pro-healing performance, highlighting its potential for clinical wound management applications.