BaTiO<sub>3</sub> Doping Enhances Ultrasound-Driven\nPiezoelectric Bactericidal Effects of Fibrous Poly(L‑Lactic\nAcid) Dressings to Accelerate Septic Wound Healing

Bacterial\ninvasion in infected skin wounds triggers inflammation\nand impedes healing. Current therapeutic strategies incorporating\ndrug interventions within wound dressings often result in drug resistance\nand delayed healing. Here, we developed a comprehensive therapeutic\nmodality integrating piezoelectric fibrous dressing with controlled\nultrasound stimulation for efficient healing in an infected wound\nmodel. The electrospun fibrous dressings composed of barium titanate\n(BaTiO<sub>3</sub>) doped poly(L-lactic acid) (PLLA) possess\nimproved piezoelectric properties due to the aligned structure and\nhigh crystallinity, which achieved superior bactericidal efficacy\nupon ultrasound-mechanical-electric conversion that results in the\nproduction of reactive oxygen species (ROS). There were 88.72% and\n90.43% killing rates of <i>Staphylococcus aureus</i> and <i>Escherichia coli</i> respectively upon ultrasound stimulation\nwithout any need for exogenous drugs, and a wound closure rate of\n95.5% within 10 days. The <i>in vivo</i> results confirmed\nthat this dressing effectively shortened wound closure time by about\n2 days, with a much-improved healing rate of 14% compared with previously\nreported therapeutic strategies. This was accompanied by reduced inflammation\nand increased re-epithelialization and angiogenesis. Hence, our synergistic\ntreatment by piezoelectric materials and controlled ultrasound stimulation\nprovides a drug-free alternative approach in regenerative tissue engineering\nfor simultaneously enhancing antibacterial effects and promoting wound\nhealing.