The Effect of Plasma Pretreatment and Cross-Linking Degree on the Physical and Antimicrobial Properties of Nisin-Coated PVA Films

Abstract

Stable antimicrobial nisin layers were prepared on the carrying medium-polyvinyl alcohol (PVA) films, crosslinked by glutaric acid. Surface plasma dielectric coplanar surface barrier discharge (DCSBD) modification of polyvinyl alcohol was used to improve the hydrophilic properties and to provide better adhesion of biologically active peptide-nisin to the polymer. The surface modification of films was studied in correlation to their cross-linking degree. Nisin was attached directly from the salt solution of the commercial product. In order to achieve a stable layer, the initial nisin concentration and the following release were investigated using chromatographic methods. The uniformity and stability of the layers was evaluated by means of zeta potential measurements, and for the surface changes of hydrophilic character, the water contact angle measurements were provided. The nisin long-term stability on the PVA films was confirmed by tricine polyacrylamide gel electrophoresis (SDS-PAGE) and by antimicrobial assay. It was found that PVA can serve as a suitable carrying medium for nisin with tunable properties by plasma treatment and crosslinking degree.

Developments in 4D-printing: a review on current smart materials, technologies, and applications

“…In addition to sequential folding and multi-stage folding, cross-folding is needed for complex designs where the folding edges can pass through each other. Teoh et al proved the effectiveness of printing a stress-releasing hole at the intersection of two folding edges where cracks were greatly reduced, as shown in Figure 3(f) [76]. Also, thicker sheets survived longer in cyclic cross-folding in their experiments.…”

“…(e) Self-nested boxes whose joints are printed with SMPs in different colors, adapted from [46]. (f) Cross-folding test specimens with and without a stress release hole, adapted from [76]. (g) Conceptual design of a material with tunable lattice structure that permits bandgap control, adapted from [77].…”

Degradable Poly(ethylene oxide)-Like Plasma Polymer Films Used for the Controlled Release of Nisin

“…Polymer materials with antimicrobial properties are of the interests to many industrial and scientific sectors. For this purpose, a number of methods aiming at biomolecules’ attachment to polymer surfaces have been developed, such as adsorption, graft polymerization, or the formation of self-assembled monolayers [ 1 , 2 , 3 , 4 ]. Noncovalent interactions can occur at some types of interfaces; however, these are often not strong enough and other ways have to be applied to increase the coating stability [ 5 ].…”

“…Plasma technologies are clean, environmentally favourable methods that allow for the chemical and mechanical properties of polymers to be controlled. Plasma can be used for surface activation of a polymer substrate or by creating a thin, polymer-like layer on the surface [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ]. So called “plasma polymerization” or plasma enhanced chemical vapor deposition (PECVD) uses plasma to activate and fragment an organic precursor in order to deposit a thin film.…”

“…Polyester-based copolymers treated by two plasma methods, a diffuse coplanar surface barrier discharge (DCSBD) and capacitively coupled radio frequency discharge plasma under an argon atmosphere, were studied by Stloukal et al [ 9 ] in order to eliminate the burst effect of the drug Temozolomide. The DCSBD technique was also used by Kolarova et al [ 3 ] to modify the surface of a polyvinyl alcohol films crosslinked by glutaric acid and study its potential as a nisin carrier. The films prepared from polyethylene and polyethylene oxide (PE + PEO) enriched with nisin proved to be more effective against selected Gram-positive bacteria than systems without PEO [ 17 ].…”