Marine-tolerant bioadhesive gel with hydrophobic microdomain-multicrosslinked network for seawater-immersed wound management.

Current gel dressings face significant challenges in seawater-immersed wound management due to their marine-intolerance, poor bioadhesion and non-antibacterial properties. Herein, we develop a multifunctional gel that integrates marine-tolerance, wet adhesion, non-invasive detachment, good antibacterial properties to resist bleeding and promote wound healing in marine environments. Our design strategy employs solvent-exchange-induced self-assembly of hydrophobic segments to engineer hydrophobic microdomains, coupled with the synergistic effects of hydrogen/ionic/coordination bonds as multicrosslinked networks, resulting in a marine-tolerant hydrogel with a "hydrophobic microdomain-multicrosslinked" network structure. An "interfacial drainage-multivalent bonding" dual-effect adhesion strategy is proposed: the interfacial drainage effect induced by silicone oil and hydrophobic microdomains enables tight tissue-gel anchoring, while the cooperative interactions of hydrogen/carbon-nitrogen/carbon-sulfur bonds synergistically achieve strong interfacial adhesion, achieving stable wet adhesion in marine environments. Furthermore, glutathione can cleave the disulfide bonds within the gel and the carbon-sulfur bonds between the gel and tissue, facilitating non-invasive detachment. Besides, the incorporation of zinc oxide nanoparticles provides broad-spectrum antibacterial functionality. Comparative animal experiments demonstrate superior performance over commercial glue in hemostatic efficiency and wound regeneration under marine conditions. This multifunctional hydrogel system establishes a new paradigm for developing advanced marine medical biomaterials through the rational integration of structural engineering and functional components.