Optimization of PVDF-TrFE Based Electro-Conductive Nanofibers: Morphology and In Vitro Response

Abstract

In this study, morphology and in vitro response of electroconductive composite nanofibers were explored for biomedical use. The composite nanofibers were prepared by blending the piezoelectric polymer poly(vinylidene fluoride–trifluorethylene) (PVDF-TrFE) and electroconductive materials with different physical and chemical properties such as copper oxide (CuO), poly(3-hexylthiophene) (P3HT), copper phthalocyanine (CuPc), and methylene blue (MB) resulting in unique combinations of electrical conductivity, biocompatibility, and other desirable properties. Morphological investigation via SEM analysis has remarked some differences in fiber size as a function of the electroconductive phase used, with a reduction of fiber diameters for the composite fibers of 12.43% for CuO, 32.87% for CuPc, 36.46% for P3HT, and 63% for MB. This effect is related to the peculiar electroconductive behavior of fibers: measurements of electrical properties showed the highest ability to transport charges of methylene blue, in accordance with the lowest fibers diameters, while P3HT poorly conducts in air but improves charge transfer during the fiber formation. In vitro assays showed a tunable response of fibers in terms of viability, underlining a preferential interaction of fibroblast cells to P3HT-loaded fibers that can be considered the most suitable for use in biomedical applications. These results provide valuable information for future studies to be addressed at optimizing the properties of composite nanofibers for potential applications in bioengineering and bioelectronics.

Optimization of Polyvinyl Alcohol-Based Electrospun Fibers with Bioactive or Electroconductive Phases for Tissue-Engineered Scaffolds

“…In this view, incorporating electroactive phases-i.e., conductive polymers (CPs)-into PVA fibers can be a promising strategy to support the electroconductive mechanisms that regulate cellular adhesion and proliferation. To date, various CPs such as polypyrrole (PPy), poly(3,4-ethylene dioxythiophene) (PEDOT, conductivity up to 10 3 S/cm [44]), and polyaniline (PANi) were found to be particularly suitable for biomedical use [45][46][47] and electrospinning was successfully employed for the manufacture of composite or blended fibers based on CPs [48][49][50]. Moreover, polyvinylpyrrolidone (PVP) has been studied before in order to improve the conductive properties of PVA as polymer coatings around 0.30 S/cm [51] and there are studies reported in the literature that focused on the effects of CPs to promote the regeneration of electroactive tissues (i.e., muscles, nerves, brain) [52].…”