Injectable and self-healing adhesive chitosan-based hydrogels for infected wound healing via anti-bacteria,...

Traditional dressings are struggle to conform to irregular wounds, which can easily lead to bacterial infections and delay wound healing. To overcome these limitations, an injectable, self-healing, and antibacterial adhesive hydrogel was developed through the incorporation of strontium-doped bioactive glass (wrapped with tannic acid/iron, TF@SBG) into a quaternized chitosan network that was functionalized with caffeic acid and oxidized hyaluronic acid via dynamic imine bonds. The hydrogel could be easily extruded through a 20 G syringe and has an adhesive strength (40.8 kPa) on porcine skin. Moreover, the hydrogel could achieve 99.9 % bactericidal efficiency within 6 min under NIR irradiation. Additionally, it eliminated the intracellular overexpression of ROS. The hydrogel promoted the migration tube of HUVECs cells with released Ca²⁺ and Si⁴⁺ from TF@SBG. The closure rate of S. aureus-infected wounds reached 94.3 % on day 11 after hydrogel treatment. This treatment effectively achieved bacterial eradication, suppressed inflammation, promoted blood vessel formation, and improved collagen deposition, significantly outperforming the blank group.