Antimicrobial Coatings with Dual Cationic and N-Halamine Character: Characterization and Biocidal Efficacy

Abstract

A method to prepare an antimicrobial coating for food-handling materials is reported. Alternating layers of branched polyethylenimine and styrene maleic anhydride copolymer were applied onto the surface of polypropylene. The resulting coatings had low surface energy and presented enhanced antimicrobial character due to the presence of both cationic and N-halamine forming structures. In its unchlorinated form, the coating inactivated Listeria monocytogenes by ∼3 logarithmic cycles. In the form of N-halamines >5 logarithmic cycles were reached. Microbial inactivation kinetics showed a Weibullian behavior when the coating was unchlorinated and a sigmoidal behavior when chlorinated. Microscopy confirmed that the reduction in the microbial load was due to biocidal effects of the coating and not bacterial adhesion onto the modified surface. The modified surface was able to be repeatedly rechlorinated. Such rechargeable antimicrobial coatings may support improving food safety by reducing cross-contamination of microorganisms from food-processing equipment.

Cationic Nanostructures against Foodborne Pathogens

“…Alternating layers of branched polyethylenimine and styrene maleic anhydride copolymer were applied onto the surface of polypropylene yielding coatings with low surface energy and enhanced antimicrobial character due to the presence of both cationic and N-halamine moieties; the coating inactivated L. monocytogenes by ~3 logarithmic cycles whereas in the form of N-halamines there was more than 5 logarithmic cycles in the viable cells counting (Bastarrachea and Goddard, 2015). In this respect, it seemed advantageous to introduce PMMA/PDDA NPs as efficient assemblies to reduce L. monocytogenes cell viability by 5 logarithmic cycles (Table 1).…”

Antimicrobial efficacy of N -halamine coatings prepared via dip and spray layer-by-layer deposition

“…PP films and Si wafers were functionalized prior to LbL deposition to improve adhesion of N-halamine coating. Each side of each PP film was exposed to UV-ozone treatment for 15 min with a Jelight Co. model 42 UVO Cleaner (Irvine, CA) to generate amine-reactive carboxylic acid groups (Bastarrachea and Goddard, 2015;Bastarrachea et al, , 2014. Silicon wafers were cleaned and oxidized with piranha solution (30% hydrogen peroxide (Fischer Scientific, Fair Lawn, NJ) and 70% sulfuric acid (Fisher Scientific, Fair Lawn, NJ)) followed by rinsing in copious water.…”

“…A method published recently was followed (Bastarrachea et al, , 2014Bastarrachea and Goddard, 2015). An isolated colony of L. monocytogenes was incubated at 37 • C for 14 h in tryptic soy broth (TSB, Becton, Dickinson and Company Sparks, MD).…”

Antimicrobial properties of bio-inspired poly(4-vinyl-2-pyridone) and itsN-alkylated cationic derivatives

“…A variety of materials has been explored for this purpose and newer strategies and techniques have been developed for the synthesis of more efficient antimicrobial materials to counter drug‐resistance of microbial strains . An extensive literature study of materials with potential antimicrobial applications shows that low‐molecular‐weight compounds have been reported of silver, titanium, copper, phenols, aldehydes, N ‐halamines, etc. But their applications on a large scale are limited due to some serious disadvantages such as high residual toxicity, environmental hazards, easy susceptibility to antimicrobial resistance, etc .…”