Piezoelectric and Dielectric Electrospun Fluoropolymer Membranes for Oral Mucosa Regeneration: A Comparative Study

Wound healing of the oral mucosa is an urgent problem in modern dental surgical practice. This research article presents and compares the findings of the investigations of the structural, physicochemical, and biological characteristics of two types of polymeric membranes used for the regeneration of oral mucosa. The membranes were prepared from poly(tetrafluoroethylene) (PTFE) and a copolymer of vinylidene fluoride and tetrafluoroethylene (VDF-TeFE) and analyzed via scanning electron microscopy, atomic force microscopy, X-ray diffraction analysis, and Fourier transform infrared spectroscopy. Investigation results obtained indicate that both types of membranes are composed of thin fibers: (0.57 ± 0.25) μm for PTFE membranes and (0.43 ± 0.14) μm for VDF-TeFE membranes. Moreover, the fibers of VDF-TeFE membranes exhibit distinct piezoelectric properties, which are confirmed by piezoresponse force microscopy and X-ray diffraction. Both types of membranes are hydrophobic: (139.7 ± 2.5)° for PTFE membranes and (133.5 ± 2.0)° for VDF-TeFE membranes. In vitro assays verify that both membrane types did not affect the growth and division of mice fibroblasts of the 3T3-L1 cell line, with a cell viability in the range of 88-101%. Finally, in vivo comparative experiments carried out using Wistar rats demonstrate that the piezoelectric VDF-TeFE membranes have a high ability to regenerate oral mucosa.

Brief Review of PVDF Properties and Applications Potential

Currently, there is an ever-growing interest in carbon materials with increased deformation-strength, thermophysical parameters. Due to their unique physical and chemical properties, such materials have a wide range of applications in various industries. Many prospects for the use of polymer composite materials based on polyvinylidene fluoride (PVDF) for scientific and technical purposes explain the plethora of studies on their characteristics "structure-property", processing, application and ecology which keep appearing. Building a broader conceptual picture of new generation polymeric materials is feasible with the use of innovative technologies; thus, achieving a high level of multidisciplinarity and integration of polymer science; its fundamental problems are formed, the solution of which determines a significant contribution to the natural-scientific picture of the modern world. This review provides explanation of PVDF advanced properties and potential applications of this polymer material in its various forms. More specifically, this paper will go over PVDF trademarks presently available on the market, provide thorough overview of the current and potential applications. Last but not least, this article will also delve into the processing and chemical properties of PVDF such as radiation carbonization, β-phase formation, etc.

Antibacterial Ferroelectric Hybrid Membranes Fabricated via Electrospinning for Wound Healing

In 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 wounds.

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.