Antimicrobials and Biocides - March 2010

This month we're looking at the use of antimicrobials and biocides in polymer products.

Antimicrobials and other biocides are chemicals that are used to selectively kill living organisms like bacteria, fungus and other micro-organisms. They have experienced a huge surge in use in recent years in a number of different environments, for example in the medical industry where hygiene is of particular importance on all surfaces, products and equipment. They are also popular in food contact and food packaging areas, household goods and, for their preservative qualities, they are used in many building materials.

Unfortunately, as with any technology, the potential is there for overuse and this can lead to a build-up of potentially dangerous chemicals within the environment, along with much more resilient bacteria. However, the benefits they offer are important; careful use of these biocides does indeed protect vulnerable members of the community and considerably extends the lifetime of many of the materials in our built environment.

Abstracts

Please see below a selection of abstracts highlighted in the March Newsletter. These are records which relate to antimicrobials or biocides that have been recently added to the Polymer Library.

Click on the 7-digit accession numbers to find out about ordering a copyright-cleared full text copy of the items shown.

1056866 - SILVER ION RELEASE FROM ANTIMICROBIAL ACRYLATE PHOTOPOLYMER LAYERS (downloadable pdf available)
Crosslinked, silver-filled, trifunctional acrylate photopolymer layers on PEEK films were prepared by a heterogeneous photocatalytic polymerisation initiation using silver-coated titanium dioxide for polymerisation initiation. The morphology of, release of silver ions from and antimicrobial efficacy of the photopolymer layers were investigated and the effect of water diffusion on silver ion release from the photopolymer layers evaluated. The amount of silver ions released from the photopolymer layers required to eliminate E coli completely within 24 h was determined. 27 refs.
Polymers and Polymer Composites, 17, No.9, 2009, p.535-543, ISSN: 0967-3911
Damm C; Muenstedt H

1056356 - STUDY OF COLORATION AND ANTIBACTERIAL EFFICIENCY OF CORONA ACTIVATED DYED POLYAMIDE AND POLYESTER FABRICS LOADED WITH AG NANOPARTICLES
The influence of dyeing on antibacterial efficiency of corona-activated polyamide and polyester fabrics loaded with colloidal Ag nanoparticles was studied as well as the influence of the presence of Ag nanoparticles on the colour change of dyed fabrics. C.I. Acid Green 25 and C.I. Disperse Blue 3 were used for dyeing of polyamide fabrics and C.I. Disperse violet 8 for polyester fabrics. The colour change of polyamide fabrics depended on the dye type, which was generally lower compared with polyester fabrics. Antibacterial efficiency of Ag-loaded fabrics was tested against Gram-positive bacterium Staphylococcus aureus and Gram-negative bacterium Escherichia coli. Corona-activated polyester and polyamide fabrics showed excellent antibacterial efficiency independently of order of dyeing and Ag loading. The morphology of fibres loaded with Ag nanoparticles was assessed by SEM and by atomic absorption spectroscopy for elemental analysis. 24 refs.
Fibers and Polymers, 10, No.5, Oct.2009, p.650-656, ISSN: 1229-9197, DOI: 10.1007/s12221-010-0650-3
Ilic V; Saponjic Z; Vodnik V; Mihailovic D; Jovancic P; Nedeljkovic J; Radetic M

1056160 - SYNTHESIS AND CHARACTERIZATION OF ACETOPHENONE BASED POLYMERIC LIGAND AND ITS POLYCHELATES WITH LN(III): THERMAL, CATALYTIC AND ANTIMICROBIAL STUDY
Lanthanum(III) polychelates were prepared using an acetophenone-based polymeric ligand and characterised by elemental analysis, electronic spectroscopy, magnetic susceptibilities, FTIR spectroscopy, NMR spectroscopy and thermogravimetry. The morphology of the polymeric ligand and polychelates was studied by scanning electron microscopy and catalytic activities of selected polychelates for the synthesis of pharmaceutical compounds investigated. The antimicrobial activity of isolated polychelates against E coli, Bacillus subtilis, Staphylococcus aureus and Saccharomyces cerevisiae was also investigated and the suitability of the polychelates as catalysts and as antifungal and antifouling coatings considered. 37 refs.
Journal of Inorganic and Organometallic Polymers and Materials, 19, No.4, Dec.2009, p.473-484, ISSN: 1574-1443, DOI: 10.1007/s10904-009-9293-5
Kapadia M; Patel M; Joshi J

1055778 - FULL OF FRAGRANCE
Exilica has found a way of incorporating volatile organic compounds, such as fragrances, flavours and antimicrobials, into thermoplastics. The company claims that typical polymer processing temperatures cause organic compounds to evaporate. It has overcome this by shielding the compounds so that they survive two exposures to heat of 220 deg.C. The team uses u-Sq beads that act as microsponges and can absorb every metal of the periodic table as well as organics such as fragrances. The size, shape and robustness allow them to be mixed into polymers, acting as a delivery vehicle to carry chemical actives. So far the beads have been added to PP, polyester, nylon 6 and EPDM, with fragrances such as almond, rosehip and jojoba oil. The company has also managed to process the polymer into fibres to be woven. Markets include automotive or aerospace, in a cabin environment. The technique would be used to mask the smell of the polymer or introduce a fragrance into the environment. Another use is for tubing that needs to be antibacterial.
Materials World, 18, No.1, Jan.2010, p.15, ISSN: 0967-8638
Connolly R

1055777 - CLEAN BILL OF HEALTH? (short article)
A polymer that combines drug-eluting and self-cleansing agents could reduce the risk of bacterial infection through urinary catheters, say researchers at Queen's University Belfast. The material, derived from esters of acrylic and methacrylic acid, is melt-extruded in a confidential multilayer extrusion mechanism to produce a catheter surface that continuously delivers antimicrobial agents over prolonged periods, minimising bacterial colonisation. The team believes its concept is unique as the material has been designed to respond intelligently in vivo to minimise the likelihood of microbial biofilm formation and encrustation on the device surface. Should the prevention mechanism fail, a patent pending self-cleansing technology involves the production of self-shedding layers manufactured from pH-erodible polymers. During the process of infection, urea is broken down by urease-producing bacteria. This produces ammonia that elevates urinary pH, triggering the surface-shedding of the material. The shedded material would be passed out with the urine so there is no issue with breakdown of materials.
Materials World, 18, No.1, Jan.2010, p.13, ISSN: 0967-8638
Price G

1055580 - TECHNOLOGICAL CHALLENGES OF ADDRESSING NEW AND MORE COMPLEX MIGRATING PRODUCTS FROM NOVEL FOOD PACKAGING MATERIALS
The challenges of addressing new and increasingly complex migration products from novel food packaging technologies are reviewed. Particular attention is paid to components of the risk assessment of packaging materials, threshold of regulation, evaluation of the Threshold of Toxicological Concern concept for application to substances in food, novel packaging materials/systems (active packaging, oxygen scavengers, ethylene scavengers, carbon dioxide scavengers/emitters, antimicrobial films), challenges with active packaging, challenges with nanotechnology, risk assessment and reports of effects of food-contact substances at very low doses (including new concerns with old constituents (bisphenol A). 98 refs. (The International Life Sciences Institute's International Symposium on 'Food Packaging: Scientific Developments supporting Safety and Quality', Prague, Czech Republic, Nov.2008)
Food Additives and Contaminants, 26, No.12, Dec.2009, p.1534-1546, ISSN: 0265-203X, DOI: 10.1080/02652030902995277
Munro I C; Haighton L A; Lynch B S; Tafazoli S

1055202 - ANTIBACTERIAL OIL-BASED POLYURETHANE FILMS FOR WOUND DRESSING APPLICATIONS
Use of a linseed oil based polyol with either/or hexamethylene diisocyanate or methylene diphenyl diisocyanate in the synthesis of a polyurethane films for application in wound dressing applications was examined and discussed. Polymers and films were characterised using Fourier transform infrared and nuclear magnetic resonance spectroscopies, gel permeation chromatography, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, contact angle measurements, dynamic mechanical analysis, water absorption properties, in-vitro degradation tests, cytotoxicity and antibacterial ability. Films prepared using mixed diisocyanates had higher glass transition temperatures, better thermal properties and lower degradation rates. Films were shown to be non cytotoxic and had antibacterial activity whether loaded with a commercial silver biocide or not. 38 refs.
Journal of Applied Polymer Science, 115, No.3, 5th Feb.2010 p.1347-1357, ISSN: 0021-8995, DOI: 10.1002/app.30788
Yucedag F; Atalay-Oral C; Erkal S; Sirkecioglu A; Karasartova D; Sahin F; Tantekin-Ersolmaz S B; Guner F S

Offer

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Also...

Why not find out more about our Biocides in Synthetic Materials Conference on 28th-29th September 2010...