Dual-Dynamic-Bond Cross-Linked Antibacterial Adhesive Hydrogel Sealants with On-Demand Removability for Post-Wound-Closure and Infected Wound Healing

TLDR

Smart bioadhesive hydrogels that self‑heal and possess antibacterial activity are highly desirable for effective wound closure and post‑closure care in clinical settings. The authors designed adhesive antioxidant self‑healing hydrogels via dual‑dynamic‑bond cross‑linking of Fe, protocatechualdehyde, and quaternized chitosan to close skin incisions and aid MRSA‑infected wound healing. The hydrogel employs dual‑dynamic bonds—a pH‑sensitive catechol–Fe coordinate bond and reversible Schiff base linkages—to provide autonomous healing, on‑demand dissolution, injectability, biocompatibility, antibacterial activity, multifunctional adhesiveness, hemostasis, and NIR responsiveness. In vivo studies in rat skin incision and infected full‑thickness wound models showed high wound closure efficacy and post‑closure care, indicating strong potential for treating skin incisions and MRSA‑infected wounds.

Abstract

The design and development of a smart bioadhesive hydrogel sealant with self-healing and excellent antibacterial activity to achieve high wound closure effectiveness and post-wound-closure care is highly desirable in clinical applications. In this work, a series of adhesive antioxidant antibacterial self-healing hydrogels with promising traits were designed through dual-dynamic-bond cross-linking among ferric iron (Fe), protocatechualdehyde (PA) containing catechol and aldehyde groups and quaternized chitosan (QCS) to enable the closure of skin incisions and promotion of methicillin-resistant Staphylococcus aureus (MRSA)-infected wound healing. The dual-dynamic-bond cross-linking of a pH-sensitive coordinate bond (catechol–Fe) and dynamic Schiff base bonds with reversible breakage and re-formation equips the hydrogel with excellent autonomous healing and on-demand dissolution or removal properties. Additionally, the hydrogel presents injectability, good biocompatibility and antibacterial activity, multifunctional adhesiveness, and hemostasis as well as NIR responsiveness. The in vivo evaluation in a rat skin incision model and infected full-thickness skin wound model revealed the high wound closure effectiveness and post-wound-closure care of the smart hydrogels, demonstrating its great potential in dealing with skin incisions and infected full-thickness skin wounds.