Antibacterial film

Antibacterial film for medical applications. [Data fromKimuni,R. ishizuka,H. Shibasaki, J., US Patent 7,279,509, Oct. 9,2007.]... 

The Japanese company Sinanen markets a zeolite called Zeomic that has been used in medical devices, refrigerators and polyurethane foam. Zeolites are also widely used in antibacterial films in Japan, whereas Technion of Israel has said it will use herbal extracts from basil instead. Another Japanese company, Toa Gohsei, has introduced a biocide called Novaron, with a zirconium phosphate base, used in plastic film, coatings, fibres and other products. Both these products have obtained US FDA and EPA safety certification. Milliken Chemical offers a zirconium phosphate-based ceramic ion-exchange polymer, AlphaSan . 

As a result of hospital infections caused by the increased resistance of bacterial strands to antibiotics inducing infections for which they are not effective, such as methiciUin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and certain strands of Escherichia coli, there is a need to develop new robust antibacterial films.These films should reduce or abate pathogenic bacteria resistant to synthetic antibiotics when administered for a long time. The films should have fast bacterial reduction kinetics, be uniform, adhese to the support, and have low cytotoxicity. That is the focus of this study addressing silver (Ag)-nitride/oxynitride bacterial inactivation films. Nitrides/oxynitrides have been shown to be resistant composites and have no or extremely low cytotoxic activity. 

Phillips, L.G. and Barbano, D.M., The influence of fat substitutes based on protein and titanium dioxide on the properties of low fat milks, J. Dairy Sci., 80, 2726, 1997. Choi, J.Y. et ah, Photocatalytic antibacterial effect of TiOj film formed on Ti and TiAg. J. Biomed. Mater. Res. B Appl. Biomater., epub., 2006. 

Figure 10.10 Antibacterial coatings and nanoparticle-embedded films obtained by cross-linking of double bonds by autoxidation.

Maizura M, Fazilah A, Norziah MH and Karim AA. 2007. Antibacterial activity and mechanical properties of partially hydrolyzed sago starch-alginate edible film containing lemongrass oil. J Food Sci 72(6) 324—330. 

Most active principles and pharmaceutical forms are processed in the presence of organic solvents or reagents. The current regulations on products generally restrict to a few p.p.m. the amount of residual solvent. This very low concentration level could favour the CO2 utilization when non-polar compounds have to be eliminated. On the other hand, the elimination of residual solvents from tablets, films or other pharmaceutical preparations in which organic solvent are involved has been addressed [15]. Another application is related to the removal of residues from medical materials such as monomers, additives or polymerization residues from polymers or elastomers. Purification of active principles includes elimination of other undesired molecules pesticides from some vegetal extracts, and antibacterials suspected of toxic co-extracts from natural sources. 

Potential applications of the LbL films as antibacterial coatings have also been reported. Multilayers of albumin/heparin can significantly reduce bacterial adhesion... 

Malcher M, Volodkin D, Heurtault B et al (2008) Embedded silver ions-containing liposomes in polyelectrolyte multilayers cargos films for antibacterial agents. Langmuir 24 10209-10215... 

Kanazawa A, Ikeda T, Endo T (1993) Polymeric phosphonium salts as a novel class of cationic biocides. III. Immobilization of phosphonium salts by surface photografting and antibacterial activity of the surface-treated polymer films. J Poly Sci A Poly Chem 31 1467-1472... 

Shieh K-J, Li M, Lee Y-H, Sheu S-D, Liu Y-T, Wang Y-C. Antibacterial performance of photocatalyst thin film fabricated by defection effect in visible light. Nanomed Nanote-chnol Biol Med 2006 2 121-6. 

TABLE 23.2. Antibacterial activity of alginate film with and without salmon testis DNA. 

Kitamura, H., Kondo, Y., Sakairi, N., and Nishi, N. 1997. Preparation and characterization of antibacterial alginate film containing DNA as a carrier of silver ion. Nucleic Acids (Symposium Series), 37,273. 

Recently, film dressings impregnated with an antibacterial (silver) for the management of infected wounds or a deodorizer (charcoal) for malodorous wounds have been introduced. 

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