Stretchable and Self-Healing Conductive Composite Hydrogel Dressings Based on Cross-Linked Gelatin for Wound Closure Under Electrical Stimulation

Hydrogels possessing both conductive characteristics and notable self-healing to achieve high wound closure effectiveness is highly desirable in clinical applications. In this work, the stretchable and self-healing conductive hydrogel dressings were designed through dual-dynamic-bond cross-linking. A stable tricomplex molecule (PA@Fe) could be formed by the pH-sensitive coordinate bond (catechol-Fe) between catechol groups in PA and ferric ions (Fe³⁺). And the conductive hydrogels with stretchable and self-healing properties could be fabricated by cross-linking of aldehyde groups in PA@Fe with gelatin through dynamic Schiff base bonds and integration of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). The as-prepared hydrogels exhibited good self-healing, adhesive ability, biocompatibility, hemostatic, and electrical conductivity. The in vivo evaluation in a 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 full-thickness skin wounds.