A Triboelectric‐Hydrogel System for Mechano‐Metabolic Re‐Coupling in Skin Expansion: Recharging From Energy Crisis

Skin expansion is an effective technique for reconstructing large skin defects, yet its clinical utility is constrained by a progressive decline in regenerative capacity of skin, largely due to an underlying cellular energy crisis. Electrical stimulation enhances mitochondrial energy production, while mechanical regulation optimizes energy allocation. We designed a biocompatible composite system (TP‐PAM/G) capable of synergistic electro‐mechanical regulation to re‐energize tissue. The system comprises a triboelectric nanogenerator layer fabricated from thermoplastic polyurethane and poly(vinylidene fluoride) that harnesses the ubiquitous mechanical forces of expansion to generate sustained mild electrical stimulation, and a hydrogel layer synthesized from polyacrylamide and gelatin that redistributes heterogeneous stresses. TP‐PAM/G exhibits excellent mechanical compliance and tissue adhesion, enabling stable, long‐lasting electric stimulation in response to expander stretching. In vitro results demonstrated that this electrical stimulation promotes the proliferation and migration of fibroblasts and endothelial cells and enhances collagen synthesis and angiogenesis. These effects were underpinned by upregulated mitochondrial activity. In vivo studies on rats revealed that TP‐PAM/G augmented energy supply by promoting mitochondrial oxidative phosphorylation, accelerating vascularization, pro‐regenerative macrophage formation, collagen deposition, and tissue maturation of expanded skin. By transforming a pathological mechanical environment into a therapeutic resource, this electro‐mechanical platform holds significant potential for clinical translation.