Fibroblast growth enhancement and antibiotic-free disinfection via microneedles with self-powered electrical stimulations.

Fibroblast growth and sterilization are two critical factors for tissue repair, particularly in infected chronic wounds. Electrical stimulation improves the efficiency of tissue repair by accelerating the migration and proliferation of fibroblasts, but preventing infection in the tissues typically requires the use of antibiotics. In this work, a self-powered nanodevice is fabricated for producing electrical stimulations for antibiotic-free disinfection. It integrates a triboelectric nanogenerator (TENG) and a PLA-Au-PPY microneedle (MN) array. The TENG generates an output voltage of up to 6 V, which promotes the proliferation of NIH-3T3 fibroblasts by about three times, demonstrating strong cell aggregation capability. The electrical stimulation also doubles the antibacterial efficiency of the PPY layer by improving the charge transfer between PPY molecules and Escherichia coli. Therefore, the designed nanodevice presents promising potential for accelerating infected tissue repair and regeneration by promoting cell viability, accelerating tissue recovery, and offering antibiotic-free sterilization.