A bioelectronic nanopillar patch for drug-free antibacterial eradication and oxidative stress-regulated wound repair

Abstract

The escalating antimicrobial resistance crisis necessitates drug-free strategies, yet nature-inspired nanopillar arrays exhibit limited efficacy (≤55%) against Gram-positive pathogens. Herein, we present a flexible bioelectronic patch (ES-NP) that achieves broad-spectrum bactericidal efficacy by synergistically coupling electrical stimulation (ES) with nanostructured mechanical disruption. The ES-NP comprises polypyrrole/polylactic acid nanopillar arrays (Ppy/PLA NP) integrated with a wire-free microampere circuit, maintaining stable conductivity under deformation. Applying ultra-low ES (~20 μA cm−2) dynamically modulates the biointerface, shifting Zeta potential and altering wettability to facilitate charge transfer. Crucially, the ES-NP exhibits a cell-type-selective dual-modulatory effect on reactive oxygen species (ROS): it significantly elevates intracellular ROS in bacteria, contributing to synergistic mechano-electrical antibacterial activity, while reducing ROS accumulation and restoring redox homeostasis in mammalian cells to attenuate inflammation. Consequently, the ES-NP achieves potent in vitro activity against E. coli (100%), S. aureus (98.22%), and MRSA (99.18%), substantially outperforming standalone nanopillar arrays. In a murine model, the ES-NP suppressed infection-induced inflammation and accelerated tissue regeneration, achieving collagen deposition-a 7.5-fold increase over controls. By integrating electrically tunable biointerfacial properties with cell-type-selective oxidative stress regulation, this drug-free platform offers a powerful solution for combating recalcitrant infections and promoting wound healing.