An Integrated Zn Battery‐Powered Iontophoresis Patch Enhances Healing of Radiation‐Induced Skin Injury by Inhibiting Ferroptosis

ABSTRACT Ferroptosis induced by ionizing radiation impairs the healing of radiation‐induced skin injury (RISI). However, conventional topical drug therapies rely primarily on passive diffusion and lack an active driving force for drug delivery, making it difficult to maintain an effective local drug concentration in the wound bed to suppress ferroptosis. Here, we developed a wound exudate‐activated iontophoresis patch with a built‐in Zn battery, termed the epigallocatechin gallate (EGCG)‐loaded MXene/poly(vinyl alcohol) battery (EMPB). An integrated porous EGCG/MXene/PVA (EMP) conductive hydrogel serves as both the Zn battery cathode and the drug reservoir, reducing interfacial resistance at the junction between the electrode layer and the drug‐loaded reservoir. When placed on the wound bed, the EMPB patch uses wound exudate as the electrolyte to activate the battery and generate a stable direct‐current microelectric field that drives iontophoresis, thereby promoting efficient EGCG delivery through electroosmotic flow. In vitro, the electrical stimulation generated by the patch accelerated cell migration, while the actively delivered EGCG upregulated the NRF2/SLC7A11/GPX4 axis to suppress radiation‐induced ferroptosis. In vivo, EMPB inhibited ferroptosis and inflammation, alleviated oxidative injury, promoted angiogenesis and collagen remodeling, and accelerated wound closure to 89.3% by day 14. Collectively, EMPB represents a promising bioelectronic platform for accelerating RISI healing.