Genes biodegradation

All the aforementioned advantages and several additional features apply to ELP-based macromolecular carriers. First, ELP-based carriers are thermally responsive. Second, ELP is a biopolymer and therefore is nontoxic and biodegradable. Third, the gene-based synthesis of ELP allows the creation of genetic fusions with functional peptides and proteins, such as targeting sequences. 

Examples of the Range of Plasmids Carrying Genes Coding Enzymes for the Biodegradation or Biotransformation of Xenobiotics... 

Harwood CS, NN Nichols, M-K Kim, JJ Ditty, RE Parales (1994) Identification of the pcaRKF gene cluster from Pseudomonas putida involvement in chemotaxis, biodegradation, and transport of 4-hydroxyben-zoate. J Bacteriol 176 6479-6488. 

Bosma T, J Damborsky, G Stucki, DB Janssen (2002) Biodegradation of 1,2,3-trichloropropane through directed evolution and heterologous expression of a haloalkane dehalogenase gene. Appl Environ Microbiol 68 3582-3587. 

The pathways for the aerobic biodegradation of alkylated benzenes have been elncidated in extensive investigations and have been discussed in Chapter 8, Part 1, so that only salient featnres are briefly snmmarized here. The genes for the degradation of toluene may be either chromosomal or... 

Panyam J, Labhasetwar V (2003) Biodegradable nanoparticles for drug and gene delivery to cells and tissue. Adv Drug Deliv Rev 55 329-347... 

Lee PW, Peng SF, Su CJ et al (2008) The use of biodegradable polymeric nanoparticles in combination with a low-pressure gene gun for transdermal DNA delivery. Biomaterials 29 742-751... 

A method was recently developed to deliver plasmid DNA locally to cells involved in wound repair (Bonadio et al., 1999 Fang et al., 1996 Shea et al., 1999). The technique involves the introduction of a porous, biodegradable polymer matrix into the wound site (Bonadio et al., 1998). The scaffold (a gene activated matrix, or GAM), in its simplest form comprises plasmid DNA and the polymer matrix (Bonadio, 2000). Naked... 

Wilson and Madsen [152] used the metabolic pathway for bacterial naphthalene oxidation as a guide for selecting l,2-dihydroxy-l,2-dihydronaphthalene as a unique transient intermediary metabolite whose presence in samples from a contaminated field site would indicate active in situ naphthalene biodegradation (Fig. 26). Naphthalene is a component of a variety of pollutant mixtures. It is the major constituent of coal tar [345], the pure compound was commonly used as a moth repellant and insecticide [345], and it is a predominant constituent of the fraction of crude oil used to produce diesel and jet fuels [346]. Prior studies at a coal tar-contaminated field site have focused upon contaminant transport [10,347], the presence of naphthalene catabolic genes [348, 349], and non-metabolite-based in situ contaminant biodegradation [343]. 

Wang J, Guo X, Xu Y, Barron L, Szoka EC Jr. Synthesis and characterization of long chain alkyl acyl carnitine esters. Potentially biodegradable cationic lipids for use in gene delivery. J Med Chem 1998 41(13) 2207-2215. 

Particles from cationic lipids may also be useful for antisense therapy of skin disease — a nontoxic increase in the oligonucleotide uptake by cultivated keratinocytes and a sebocyte cell line has been reported [66]. Moreover, cationic dendri-mers also efficiently transfer reporter gene DNA to human keratinocytes cultivated in vitro. In the skin of hairless mice, in vivo transfection was possible with complexes, yet reporter gene expression was localized to perifollicular areas. Transfection, however, failed with the naked plasmid. For prolonged contact, biodegradable membranes coated with dendrimer/DNA complexes were used [67]. This hints at a follicular uptake of these complexes and indicates that gene transfection also may be possible with human skin, which has a thicker stratum comeum compared with mouse skin (eight to ten vs. two to three layers [58]). 

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