Flexible nano-piezoelectric membranes with spontaneous electric field generation for bacteria elimination and wound healing

Electrical stimulation therapy has attracted widespread attention for its advantages of promoting cell proliferation and tissue regeneration, accelerating skin barrier restoration, and reducing scars. Its effect on accelerating wound healing has been clinically proven. However, traditional electrical stimulation therapy requires large power supply devices, which are inconvenient to carry and use. Therefore, self-powered flexible nano-piezoelectric membranes were developed in this work, which can generate electric field under mechanical stimulation to effectively eliminate bacteria and accelerate wound healing. In this work, poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) piezoelectric membranes were fabricated by electrospinning, and better piezoelectric properties were obtained by adding tetrabutylammonium chloride (TBAC), and their antibacterial and pro-healing effects were investigated with or without mechanical stimulation. Results showed that the output voltage of P(VDF-TrFE)/TBAC piezoelectric membrane was about 5.3 times higher than that of P(VDF-TrFE). Furthermore, the P(VDF-TrFE)/TBAC piezoelectric membrane had excellent antibacterial effect against both Escherichia coli and Staphylococcus aureus after mechanical stimulation, and the inhibition rates of Staphylococcus aureus and Escherichia coli were 71.43% and 97.25%, respectively. Meanwhile, the results of in vivo and in vitro healing promotion experiments showed that P(VDF-TrFE)/TBAC piezoelectric membrane was effective in promoting cell growth and wound healing after mechanical stimulation, the wound was almost completely healed on the 7th day, and the healing rate was increased by about 37% compared with the blank. The P(VDF-TrFE)/TBAC flexible piezoelectric membrane is effective in electrical stimulation for wound healing, and it has potential applications in wound treatment. Graphical abstract