Surface, antimicrobial, polymeric

Antimicrobials may be incorporated into a plastics formulation to preserve the polymeric material by destroying or inhibiting the growth of microorganisms on the product surface. Antimicrobials should be environmentally safe and non-toxic to humans, easy to store and handle, and compatible with polymers and other formulation ingredients. Recently there has been a demand for antimicrobials in polymer products such as toys, cutting boards, kitchen utensils and hospital faucet and door handles. 

The increasing occurrence of microbial and nosocomial infection has stimulated research activities into antimicrobial polymers and textiles [19, 25, 34]. Most medical textiles and polymeric materials used in hospitals are conductive to crosstransmission of diseases, as most microorganisms can survive on these materials for hours to several months [17, 26]. Thus, it would be advantageous for polymeric surfaces and textile materials to exhibit antibacterial properties so as to reduce and prevent disease transmission and cross-contamination within and from hospitals. N-halamines exhibit a similar antimicrobial potency to chlorine bleach, one of the most widely used disinfectants, but they are much more stable, less corrosive and have a considerably reduced tendency to generate halogenated hydrocarbons, making them attractive candidates for the production of antimicrobial polymeric materials. N-halamine compounds are currently used as antimicrobial additives to produce polymers with antimicrobial and biofilm-limiting activities. 

A new methodology to fabricate antimicrobial polymeric surfaces which exhibit antiadhesive properties has been developed using PP modified by air plasma and has the potential to be an excellent coating surface with activity against several pathogenic bacteria. 

The ability to create essentially irreversible polymeric coatings of cationic silanes on surfaces and the ability of these modified surfaces to kill and/or control microorganisms has been demonstrated in laboratory and real world situations. A large number of microbological techniques have been found useful in determining the antimicrobial activity of a wide variety of surfaces with polymeric antimicrobials. This has provided considerable insight into the mode of antimicrobial action of these compounds. 

Another kind of contact-active antimicrobial surface was achieved by tethering antimicrobial peptides to surfaces [62], If such peptides were exclusively membrane-active they could not work like in solution but would be immobilized via a polymeric spacer that could potentially cross the cell wall. The latter was demonstrated by the group of Dathe, who immobilized cationic antimicrobial peptides on PentaGels [63], Also, the well-known antimicrobial peptide magainin I... 

Gettings RL, White WC (1987) Formation of polymeric antimicrobial surfaces from organofunctional silanes. Polym Mater Sci Eng 57 181-185... 

The present invention provides for medical devices which are antiinfective as a resirlt of antinfective agents impregnated onto their surfaces and/or antinfective activity incorporated into their access sites. It is based, at least in part, on the discovery that certain combinations of antimicrobial agents and solvents change the surface characteristics of polymeric medical devices, thereby facilitating the retention of antimicrobial agents. It is further based on the discovery that the incorporation of antinfective polymeric inserts into the access sites of a medical device provides improved antinfective activity. 

The mechanisms by which microbes attach to surfaces and viability of the microorganisms are discussed. Representative microorganisms (bacteria, algae, fungi, viruses and other microbes) are listed that are problematical from a medical or health perspective and/or that lead to unwanted damage in materials. Adhesion and persistence of microorganisms, methods of decontamination of polymeric substrates, durability of antimicrobial agents on materials, and applieations, are discussed. 19 refs... 

Composites utilizing cellulose fibers have been prepared with many different materials, especially polymers. It has been well demonstrated that these fibers help to alter and in general enhance the physical properties of polymeric composites [140, 149-157]. Additionally, their bio-degradability and biocompatibility enables cellulose-reinforced materials to be suitable for bio-scaffolding in medical applications, if the polymeric component is also biocompatible [140, 158]. Some surface modifications have been performed on cellulose to add selected characteristics, such as antimicrobial properties to polymeric matrixes [140,159]. 

Nanofibrillar chitin hydrogels are biodegradable, biocompatible, and nontoxic, and thus show promise for biomedical applications. The protonation of amino groups on the surface of chitin allows its application in wound dressings due to the antimicrobial properties of cationic gels [130]. Polymeric fibers that mimic the structure and function of the extracellular matrix are also of interest in tissue engineering and cell culture. Chitin nanofibers can promote cell attachment and show potential as extracellular matrix mimics [29, 125]. 

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