Antibacterial coating

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

In other cases fullerene antibacterial action takes place after photoirradiation of fulleropyrrolidinium salts. It is not yet clear if the photodynamic action implies the participation of superoxide and hydroxyl radicals (type I mechanism) or singlet oxygen (type II mechanism) but the efficacy is really interesting with the death of more than 99.9% of bacterial and fungal cells and a special selectivity for microbes over mammalian cells (Tegos et al., 2005). Also a sulfobutyl fullerene derivative is able to inhibit environmental bacteria after photoirradiation and it exerts its action on E. coli even if incorporated in coated polymer (Yu et al., 2005). 

There are many applications in the medical and food sanitization fields for which antimicrobial surface coatings are needed. There are commercially available products making antibacterial claims, but they are limited in their applications by such factors as a poor spectra of activity, high cost, and toxicity. Work in the laboratories at Auburn Uifiversity over the past two decades has established a novel class of heterocyclic orgaific compounds termed A-halamines that have been demonstrated to be excellent antimicrobial materials for a broad variety of applications. 

Photocatalysis based on TiO has attracted much attention for enviromnental cleaning and antibacterial applications [1-3], In order to synthesize TiO nanoparticles, various modification of the sol-gel method have been widely used. However, sol-gel prepared TiO requires a post-calcination process for crystallization [4], which limits the applicability of TiO coatings to temperatnre resistant substrates. On the other hand, the solvothermal method, which does not need to be followed... 

Nablo BJ, Rothrock AR, Schoenfisch MH. Nitric oxide-releasing sol-gels as antibacterial coatings for orthopedic implants. Biomaterials 2005, 26, 917-924. 

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

Fig. 10 Example of a contact-killing and microbe-releasing surface. The scheme shows the design of a two-level dual-functional antibacterial coating containing both quarternary ammonium salts and silver. The coating process begins with LbL deposition of a reservoir made of bilayers of PAH and PAA. (A) Cap region made of bilayers of PAH and SiC>2 nanoparticles (NP) is added to the top. (B) The SiC>2 nanoparticle cap is modified with a quarternary ammonium silane (QAS) PEM polyelectrolyte multilayer. (C) Ag+ is loaded into the coating using the available unreacted carboxylic acid groups in the LbL multilayers. Scheme was reproduced from [138]...

Gollwitzer H, Ibrahim K, Meyer H et al. (2003) Antibacterial poly(D,L-lactic acid) coating of medical implants using a biodegradable drug delivery technology. J Antimicrob Chemother 51 585-591... 

Li Z, Lee D, Sheng XX et al. (2006) Two-level antibacterial coating with both release-killing and contact-killing capabilities. Langmuir 22 9820-9823... 

Guyomard A, De E, Jouenne T et al. (2008) Incorporation of a hydrophobic antibacterial peptide into amphiphilic polyelectrolyte multilayers a bioinspired approach to prepare biocidal thin coatings. Adv Funct Mater 18 758-765... 

Silver coated textiles Recently, a new mode of antibacterial/antimicrobial therapy in AD has been introduced the use of antibacterial silver coated textiles. In an open-labeled controlled side-to-side comparative trial, silver-coated textiles were able to reduce S. aureus-colonization significantly already two days after initiation lasting until the end of the treatment. Even seven days after cessation, S. aureus-density remained significantly lower compared to the baseline. Clinical improvement paralleled with reduction of 5. aw/mv-colonization.105... 

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