Antibacterial ferroelectric hybrid membranes fabricated via electrospinning for wound healing

n the present study, wound healing ferroelectric membranes doped with zinc oxide nanoparticles were fabricated from vinylidene fluoride-tetrafluoroethylene copolymer and polyvinylpyrrolidone using the electrospinning technique. Five different ratios of vinylidene fluoride-tetrafluoroethylene to polyvinylpyrrolidone were used to control the properties of the membranes at a constant zinc oxide nanoparticle content. It was found that an increase of polyvinylpyrrolidone content leads to a decrease of the spinning solution conductivity and viscosity, causing a decrease of the average fiber diameter and reducing their strength and elongation. By means of X-ray diffraction and infrared spectroscopy, it was revealed that increased polyvinylpyrrolidone content leads to difficulty in crystallization of the vinylidene fluoride-tetrafluoroethylene copolymer in the ferroelectric β-phase in membranes. Changing the ratio of vinylidene fluoride-tetrafluoroethylene copolymer and polyvinylpyrrolidone with a constant content of zinc oxide nanoparticles is an effective approach to control the antibacterial properties of membranes towards Staphylococcus aureus. After carrying out in vivo experiments, we found that ferroelectric hybrid membranes, containing from five to ten mass percent of PVP, have the greatest wound-healing effect for the healing of purulent wound

Effect of heat treatments and aggressive media on mechanical properties of porous polytetrafluoroethylene membranes fabricated via electrospinning

Electrospinning is a modern alternative to the expanded method for producing porous polytetrafluoroethylene membranes. High strength and relative elongation, as well as the ability to maintain these properties for a long time when exposed to aggressive media at high temperatures, determine the application scope of the electrospun polytetrafluoroethylene membranes. Herein, we report the effect of Polytetrafluoroethylene/Polyvinyl alcohol ratio in the electrospinning solution, heat treatment mode (quenching and annealing) and aggressive media at high temperatures on the shrinkage, tensile strength and relative elongation of electrospun polytetrafluoroethylene membranes. We found that decreased Polytetrafluoroethylene/Polyvinyl alcohol ratio in the electrospinning solution increases shrinkage, but improves tensile strength and relative elongation of polytetrafluoroethylene membranes. Quenching of membranes after heating is a more preferable treatment option than annealing as it allows to obtain the membrane with less shrinkage and better mechanical properties. Exposure of electrospun polytetrafluoroethylene membranes to concentrated mineral acids and alkalis, a bipolar aprotic solvent, engine oil and deionized water at 100 degrees C for 48 h did not deteriorate their tensile strength and relative elongation

Composite Ferroelectric Membranes Based on Vinylidene Fluoride-Tetrafluoroethylene Copolymer and Polyvinylpyrrolidone for Wound Healing

Wound healing is a complex process and an ongoing challenge for modern medicine. Herein, we present the results of study of structure and properties of ferroelectric composite polymer membranes for wound healing. Membranes were fabricated by electrospinning from a solution of vinylidene fluoride/tetrafluoroethylene copolymer (VDF–TeFE) and polyvinylpyrrolidone (PVP) in dimethylformamide (DMF). The effects of the PVP content on the viscosity and conductivity of the spinning solution, DMF concentration, chemical composition, crystal structure, and conformation of VDF–TeFE macromolecules in the fabricated materials were studied. It was found that as PVP amount increased, the viscosity and conductivity of the spinning solutions decreased, resulting in thinner fibers. Using FTIR and XRD methods, it was shown that if the PVP content was lower than 50 wt %, the VDF–TeFE copolymer adopted a flat zigzag conformation (TTT conformation) and crystalline phases with ferroelectric properties were formed. Gas chromatography results indicated that an increase in the PVP concentration led to a higher residual amount of DMF in the material, causing cytotoxic effects on 3T3L1 fibroblasts. In vivo studies demonstrated that compared to classical gauze dressings impregnated with a solution of an antibacterial agent, ferroelectric composite membranes with 15 wt % PVP provided better conditions for the healing of purulent wounds