Ultrasmall BaTiO ₃ Nanoparticle-Based Piezoelectric Adhesive Bandage for Ultrasound-Driven, Drug-Free Antibacterial Wound Healing

Bacterial infections pose a significant barrier to wound healing, intensifying inflammation, hindering tissue regeneration, and exacerbating antibiotic resistance. Traditional dressings only passively protect or deliver antibiotics but lack dynamic therapeutic capabilities. We present a piezoelectric adhesive bandage integrating ∼6.7 nm BaTiO₃ nanoparticles within biocompatible PVA-agarose hydrogel for ultrasound-driven, drug-free antibacterial wound repair. Under ultrasound, embedded ultrasmall BaTiO₃ nanoparticles generate an internal piezoelectric field, promoting electron-hole separation. These charge carriers react with water and oxygen to produce reactive oxygen species (ROS), eradicating >90% <i>Staphylococcus aureus</i> in vitro in 10 min. The bandage has good mechanical strength, uniform nanoparticle dispersion, and strong piezoelectricity. In vitro, it boosts fibroblast migration and angiogenesis- and matrix-related gene expression. In a rat model of infected wounds, the bandage achieved 92.6% wound closure by day 14, with better epithelial regeneration, collagen deposition, neovascularization, and fewer inflammatory cytokines.