Blood-responsive mussel-inspired hydrogels for hemostasis, antibacterial action, and wound healing

Rapid hemostasis, potent antimicrobial activity, and efficient wound management are critical factors in enhancing the survival of trauma patients. Chitosan, as a green and sustainable biomaterial with low cost, degradability and biocompatibility, is widely used in the biomedical field. However, chitosan dissolves in an acidic environment, which is not conducive to wound healing. In this study, chitosan was chemically modified to address this limitation. A mussel-inspired hydrogel composed of caffeic acid-grafted chitosan, gallic acid-grafted chitosan, and oxidized microcrystalline cellulose (CHI-C/CSG/OMCC) was designed. This hydrogel exhibits blood-responsive gelation behavior and offers a synergistic combination of tissue adhesion, antimicrobial properties, and tissue repair capabilities. The carboxyl, hydroxyl, phenolic hydroxyl and aldehyde groups within the hydrogel system endowed the hydrogel with excellent adhesion properties (53.1 kPa adhesion strength to porcine skin-adherent tissues), biocompatibility, and excellent antimicrobial properties. Surprisingly, this hydrogel not only achieved rapid and effective hemostasis, but also effectively promoted wound healing in a mouse skin injury model. In addition, its remarkable efficacy in stopping bleeding within approximately 2 min without rebleeding was demonstrated in a porcine model of acute gastrointestinal hemorrhage in the esophagus, stomach, and intestines. This blood-responsive ternary hydrogel offers a promising alternative to wound management materials due to its excellent overall performance and superior efficacy in all phases of wound healing.