ZnO@PVDF/CS Piezoelectric Nanofibrous Membrane Promotes the Healing of Infected Wounds Stimulated by Low-Intensity Pulsed Ultrasound

As the largest organ interfacing directly with the external environment, skin is highly vulnerable to injuries from trauma (e.g., vehicular accidents, lacerations, burns) or surgical resection. The healing of such defects is frequently protracted and susceptible to microbial infection, which exacerbates recovery timelines. Bioelectric signaling has emerged as a critical modulator of wound repair processes. Concurrently, decades of antibiotic misuse have precipitated widespread bacterial resistance, with biofilm formation further complicating therapeutic efficacy. Consequently, developing safe and effective antimicrobial strategies to shield wounds against drug-resistant pathogens is imperative. Metallic nanoparticles, notably zinc oxide nanoparticles (ZnO-NPs), have garnered significant attention for their potent antibacterial properties. To utilize this advantage, we prepared a piezoelectric nanofibrous membrane via electrospinning. This membrane integrates polyvinylidene fluoride (PVDF) for piezoelectricity, ZnO-NPs for antimicrobial activity, and chitosan (CS) for hemostatic and supplementary antibacterial functions. Bioelectric stimulation was achieved through dual mechanisms: exogenous low-intensity pulsed ultrasound (LIPUS) and endogenous mechanical motion from the rat model. The resulting ZnO@PVDF/CS membrane exhibited excellent material properties, strong antimicrobial efficacy, and accelerated in vivo wound healing in rat models.