Fabrication of PEOT/PBT Nanofibers by Atmospheric Pressure Plasma Jet Treatment of Electrospinning Solutions for Tissue Engineering.

This study focuses on the enhanced electrospinning of 300-Polyethylene oxide-polyethylene oxide terephthalate/polybutylene terephthalate (PEOT/PBT). An atmospheric pressure plasma jet for liquid treatment is applied to a solution with 9 w/v% PEOT/PBT dissolved in either chloroform (CHCl3 ), CHCl3  + N,N-dimethylformamide (DMF), CHCl3  + methanol (MeOH), or CHCl3  + hexafluoroisopropanol (HFIP). For all conditions, the plasma-treated samples present better-quality fibers: less or no-beads and uniform fiber diameter distribution. Except for CHCl3  + DMF, no significant changes to the material bulk are detected, as shown with size exclusion chromatography (SEC). X-ray photoelectron spectroscopy (XPS) spectra performed on nanofibers record an increase in C-C bonds for the CHCl3  + DMF combination upon plasma modification, while a shift and slight increase in oxygen-containing bonds is found for the CHCl3  + HFIP and CHCl3  + MeOH mixtures. MTT assay shows no-cytotoxic effects for CHCl3  + DMF, while a better cellular adhesion is found on nanofibers from CHCl3  + MeOH and CHCl3  + HFIP. Among the examined additives, MeOH is preferable as it produces beadless electrospun nanofibers with an average diameter of 290 ± 100 nm without causing significant changes to the final nanofiber surface properties.