Ultratough,\nSelf-Healing, and Tissue-Adhesive Hydrogel for Wound Dressing

Abstract

A hydrogel\nfor potential applications in wound dressing should possess several\npeculiar properties, such as efficient self-healing ability and mechanical\ntoughness, so as to repair muscle and skin damage. Additionally, excellent\ncell affinity and tissue adhesiveness are also necessary for the hydrogel\nto integrate with the wound tissue in practical applications. Herein,\nan ultratough and self-healing hydrogel with superior cell affinity\nand tissue adhesiveness is prepared. The self-healing ability of the\nhydrogel is obtained through hydrogen bonds and dynamic Schiff cross-linking\nbetween dopamine-grafted oxidized sodium alginate (OSA-DA) and polyacrylamide\n(PAM) chains. The covalent cross-linking is responsible for its stable\nmechanical structure. The combination of physical and chemical cross-linking\ncontributes to a novel hydrogel with efficient self-healing ability\n(80% mechanical recovery in 6 h), high tensile strength (0.109 MPa),\nand ultrastretchability (2550%), which are highly desirable properties\nand are superior to previously reported tough and self-healing hydrogels\nfor wound dressing applications. More remarkably, due to plenty of\ncatechol groups on the OSA-DA chains, the hydrogel has unique cell\naffinity and tissue adhesiveness. Moreover, we demonstrate the practical\nutility of our fabricated hydrogel via both <i>in vivo</i> and <i>in vitro</i> experiments.