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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. [ABSTRACT FROM AUTHOR]

Wound healing is a complicated process that can be susceptible toward infection caused by bacteria. The surging drug resistance has become one of the biggest challenges to the treatment of these infections in public health. Herein, a new asymmetrical aza-boron-dipyrromethene (ABDP) probe is prepared and encapsulated with cholesterol-modified polyethylene glycol polymer (Chol-PEG 2000-NH 2) to construct a PTT/PDT dual-modality antibacterial agent (the ABDP NPs) and provide a new material for the treatment of MRSA-based infections. The ABDP NPs show remarkable wide UV–Vis absorption at 300–850 nm and superior bactericidal effects against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Methicillin-resistant S. aureus (MRSA), which can be controlled by a phototheranostic antibacterial switch (808 nm laser). Histological analysis indicates that wounds treated by the ABDP NPs plus NIR laser irradiation exhibit more complete re-epithelialization, abundant collagen fibers, and higher hair follicle numbers than the vancomycin-treated group. This study provides a promising perspective using aza-BODIPY dye for the treatment of multidrug-resistant bacteria-based infections and clinical applications in the future. [ABSTRACT FROM AUTHOR]

As one of the components of the lithium ion batteries (LIBs), the separator plays a vital part in the safety and electrochemical performance. In this work, a ZrO2-ceramic-coated polyvinylidene fluoride (PVDF) nanofibrous separator for LIBs was successfully prepared by electrospinning, subsequent dopamine hydrophilic modification and biomimetic mineralization process. These preparation processes were environmentally friendly and simple. The ZrO2-ceramic coating endows the separator with outstanding electrolyte wettability and thermal stability. To be specific, the separator exhibits higher ionic conductivity (2.261 mS cm−1), high porosity (85.1%) and favorable electrolyte wettability (352%), and lower interfacial impedance (220 Ω). Compared with commercial polyolefin separator and PVDF nanofibrous separator, the ZrO2-ceramic-coated PVDF nanofibrous separator exhibits excellent rate performance and well cyclic stability. Most importantly the ZrO2–PDA/PEI–PVDF separator can still maintain a complete structure even at a high temperature of 300 °C. Compared with commercial separators, it greatly improves the safety of lithium ion batteries at high temperature. Therefore, this separator has far-reaching prospects for improving lithium ion safety and cycle stability. [ABSTRACT FROM AUTHOR]