Metal–Polyphenol–Collagen Self-Assembled Bioadhesive with Immune Regulation for Infected Wound Healing

Destroyed skin barriers for extensive cutaneous wounds often bring about delayed healing and even systemic complications. Multifunctional dressing materials targeting different stages of the healing process have drawn growing concerns to obtain desirable tissue repair. In this study, a self-assembled collagen/tannic acid–zinc (ColTA-Zn) bioadhesive powder with a dual cross-linking network was developed for infected wound healing. The hydrogen bonds between collagen chains and tannic acid, together with the metal coordination formed by Zn²⁺ and tannic acid, mainly contribute to the adhesion performances and mechanical properties of the bioadhesive. Furthermore, the biocompatible ColTA-Zn powder exerts antimicrobial effects on Staphylococcus aureus. Crucially, the ColTA-Zn powder can absorb blood or exudate quickly along with a rapid gelation and adhere to the wound surface once contacting the wounds, playing the roles of adsorption, convergence, and adhesion. During the healing process, the self-gelled ColTA-Zn dressing exhibits an immunomodulatory effect on macrophage polarization and ultimately accelerates wound healing. Therefore, the self-assembled, accessible, and user-friendly ColTA-Zn adhesive might be a potential candidate for wound dressings with adhesive, anti-infectious, and conglutinant functions.