Injectable Adhesive Self-Healing Multiple-Dynamic-Bond Crosslinked Hydrogel with Photothermal Antibacterial Activity for Infected Wound Healing

The development of multifunctional injectable adhesive hydrogels with self-healing capacity, shape adaptability, on-demand removability, and excellent photothermal antibacterial activity to promote bacteria-infected wound healing is highly recommended in practical applications. In this work, an injectable adhesive self-healing multiple-dynamic-bond crosslinked hydrogel was formed by a multiple-dynamic-bond crosslinked network of dynamic borate/didiol interactions, hydrogen bonding, and Schiff base bond. The introduction of Mussel-inspired catechol groups into the hydrogels could endow tissues with adhesive properties, and the hydrogel could adhere well to the skin under water with good shape adaptability under bent and twisted states. The mechanical and adhesive properties improved through the introduction of borate/didiol interactions into the catechol-modified hydrogel with dynamic Schiff base crosslinking at low cost and easy preparation, and the adhesive hydrogel could be removed without second damage to the wound. Moreover, polydopamine nanoparticles (PDA NPs) were introduced into the hydrogels through Schiff base reactions between the quinone group on PDA NPs and the primary amine in glycol chitosan (GC), resulting in an efficient photothermal antibacterial activity with uniformly dispersed PDA NPs in the hydrogel. And the hydrogels illustrated good cytocompatibility and hemocompatibility. Finally, they could be injected to fully fill irregular wounds and significantly promote bacteria-infected wound healing by reducing the inflammatory response, accelerating collagen deposition, and promoting blood vessel reconstruction. Therefore, this demonstrated their superiority in serving as multifunctional dressings for treating a bacteria-infected wound.