Nanozyme-Crosslinked Poly(Thioctic Acid)-Based Hydrogel Adhesives with Coral-Like Structure for Promoting Wet Adhesion, Antibacterial Active, and Wound Healing.

Uncontrolled traumatic hemorrhage in emergency and surgical settings frequently leads to prolonged bleeding time, increased infection risks, and delayed wound healing. To overcome these issues, a novel multifunctional biomimetic PTALi-SCAA hydrogel adhesive is prepared by crosslinking caffeic acid-Ag (CAA) nanozyme with the double network of poly(thioctic acid)Li+-sericin (PTALi-S). The introduction of CAA nanozyme significantly promoted wet tissue adhesion (48.26 kPa), hemostatic efficacy (within 30 s), and antibacterial properties (>99%) of the PTALi-SCAA hydrogel adhesives. On the one hand, the CAA nanozyme can regulate the oxidation process of the catechol groups of caffeic acid (CA) by electron transfer and maintain the quantity of catechol groups via enzyme-like catalytic activity to enhance long-term wet adhesiveness and rapid hemostasis abilities of the hydrogel adhesives. On the other hand, the CAA nanozyme may generate reactive oxygen species (ROS) and control the release of Ag+ to improve the antibacterial properties of the hydrogel adhesives. In vivo studies confirmed that the hydrogel adhesives effectively sealed skin incisions, accelerated blood clotting, and inhibited wound infection. Histological analysis (H&E and Masson's strichrome staining) combined with CD3l immunofluorescence demonstrated that the hydrogel adhesives reinforced re-epithelialization, collagen deposition, and angiogenesis. These results highlighted the PTALi-SCAA hydrogels as a versatile bioadhesive platform for facilitating wound healing.