Improving the Stability of Amino-Containing Plasma Polymer Films in Aqueous Environments

Plasma surface modification strategies for the preparation of antibacterial biomaterials: A review of the recent literature

Plasma-based strategies offer several advantages for developing antibacterial biomaterials and can be used directly or combined with other surface modification techniques. Direct plasma strategies can be classified as plasma surface modifications that derive antibacterial property by tailoring surface topography or surface chemistry. Nano patterns induced by plasma modification can exhibit antibacterial property and promote the adhesion and proliferation of mammalian cells, creating antibacterial and biocompatible surfaces. Antibacterial effect by tailoring surface chemistry via plasma can be attained by either creating bacteriostatic surfaces or bactericidal surfaces. Plasma-assisted strategies incorporate plasma processes in combination with other surface modification techniques. Plasma coating can serve as a drug-eluting reservoir and diffusion barrier. The plasma-functionalized surface can serve as a platform for grafting antibacterial agents, and plasma surface activation can improve the adhesion of polymeric layers with antibacterial properties. This article critically reviews plasma-based strategies reported in the recent literature for the development of antibacterial biomaterial surfaces. Studies using both atmospheric and low-pressure plasmas are included in this review. The findings are discussed in terms of the trends in material and precursor selection, modification stability, antibacterial efficacy, the choice of bacterial strains tested, cell culture findings, critical aspects of in vitro performance testing and in vivo experimental design.

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.