Antimicrobial polymer coatings

Antimicrobial polymer coatings are intended for modification of packaging materials to inhibit spoilage of foodstuffs (bakery, confectionery, dairy, meat, fish, fruit and vegetables) [95], for which they are filled with antimicrobial components [96] such as ... 

Formation and protective mechanisms of antimicrobial polymer coatings are in principal the same as in inhibited paint-and-varnish coats [97],... 

Eknoian MW, Worley SD, Bickert J et al. (1998) Novel antimicrobial iV-halamine polymer coatings generated by emulsion polymerization. Polymer 40 1367-1371... 

Kristinsson KG, Jansen B, Treitz U et al. (1991) Antimicrobial activity of polymers coated with iodine-complexed polyvinylpyrrolidone. J Biomater Appl 5 173-184... 

The use of polymeric ammonium salts and a sulfonic acid salt of sodium is an easy and efficient way of coating fabrics furthermore, employing the layer-by-layer (LbL) deposition technique can broaden the application of N-halamine biocides in other polar substances for use as antimicrobial coatings. Branched PEI, polypropylene (PP) and styrene maleic anhydride copolymers are a very good coating for food packaging materials, possibly due to the presence of both cationic- and N-halamine-forming structures. N-halamine cationic antimicrobial polymers based on (acrylamidopropyl)trimethylammonium chloride, PDDA chloride and poly(2-acrylamido-2-methylpropane sulfonic acid sodium salt) have been synthesised and coated onto cotton fabrics via an LbL deposition technique. 

Functionalised antimicrobial polymers can be developed by chain transfer (reversible addition-fragmentation transfer) polymerisation involving amino derivatives of methacrylate containing polydimethylsiloxane, which are further quarternised to yield new cationic polymers and are useful as antimicrobial coatings. 

Another sector clearly benefiting from smart polymers is the food industry as smart micro- or nanoparticles have been used for incorporating active ingredients (e.g., ascorbic add (Devi and Kakati, 2013) or olive oil (Devi et al, 2012)) in food or antimicrobial polymers such as chitosan, which have been used to fabricate edible coatings (Femandez-Saiz et al, 2010). 

Although a few mechanisms have so far been proposed to explain the antimicrobial properties exhibited by proanthocyanidins (e.g., inhibition of extracellular enzymes) [86], Jones et al. [83] postulated that their ability to bind bacterial cell coat polymers and their abihty to inhibit cell-associated proteolysis might be considered responsible for the observed activity (Table 1). Accordingly, despite the formation of complexes with cell coat polymers, proanthocyanidins penetrated to the cell wall in sufficient concentration to react with one or more ultra-structural components and to selectively inhibit cell wall synthesis. Decreased proteolysis in these strains may also reflect a reduction of the export of proteases from the cell in the presence of proanthocyanidins [83]. 

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