Surface-engineered triboelectric nanogenerator patches with drug loading and electrical stimulation capabilities: Toward promoting infected wounds healing

Skin wounds are commonly seen, while their repair can be severely affected due to bacterial infections. Using the wearable triboelectric nanogenerators (TENGs) as miniaturized electrical stimulation (ES) devices at the wound site is an appealing strategy for infected skin wounds repair. However, the development of an integrated TENG patch to achieve in situ ES as well as controlled drug loading/release remains challenging. Herein, a flexible TENG patch is rationally designed with a surface-engineered electrode possessing Mg-Al layered double hydroxide as a smart drug container and friction layer to accelerate infected wounds healing. The surface engineered TENG patch exhibits improved triboelectricity-generation performance and effective delivery of minocycline. In vitro results show that such TENG patches can kill almost 100% of E. coli and S. aureus, and greatly promote the proliferation and migration of fibroblasts. Upon application to the S. aureus-infected wounds with full-thickness skin defect in mice, the patches can inhibit wound bacteria (similar to 96.7%) and facilitate the skin tissue repair process, allowing the infected wound to heal within 10 days. Moreover, a novel antibacterial mechanism of a low-intensity electric field from alternating current is proposed, which can be ascribed to the accumulated electrical breakdown effect and H2O2 produced by ES to rupture the bacterial membranes. This work offers a convenient solution for infected wound treatment and opens a new route for personalized healthcare devices for microbial management.