Gene transfer methods

Classical gene transfer methods still in use today are diethylamino ethyl (DEAE)-dextran and calcium phosphate precipitation, electroporation, and microinjection. Introduced in 1965, DEAE-dextran transfection is one of the oldest gene transfer techniques [2]. It is based on the interaction of positive charges on the DEAE-dextran molecule with the negatively charged backbone of nucleic acids. The DNA-DEAE-dextran complexes appear to adsorb onto cell surfaces and be taken up by endocytosis. 

Agrobacterium-mQdi iQd DNA transfer technique and direct gene transfer into protoplasts on the basis of the electroporation technique have frequently been used for the gene transfer methods in plants. However, these methods were hardly adapted to monocotyledonous plants or to varieties in which regeneration system was not established. These deficiencies found in gene transfer techniques will be largely overcome if pollen could be used as a DNA vector. 

Lindell J, Girard P, Muller N, Jordan M, Wurm FM (2004), Calfection a novel gene transfer method for suspension cells, Biochim. Biophys. Acta 1676 155-161. 

Between the methods of Agrobacterium and microprojectile transfer, nearly every plant species can be transformed effectively [35]. However, these methods are covered by patent claims and may result in limited transformation efficiency for some cell types. For this reason, the use of alternative gene-transfer methods is an active area of research for all cell types. Alternative gene-transfer techniques include electroporation, microinjection, liposome fusion, direct transfer into protoplasts, and laser treatment [38]. In electroporation, DNA is transferred into the cell using a high-voltage electrical pulse [39]. Standard... 

Laparra, H., Burrus, M., Hunold, R., Damm, B., Bravo-Angel, A.-M., Bronner, R., and Hahne, G., Expression of foreign genes in sunflower (Helianthus annuus L.) evaluation of three gene transfer methods, Euphytica, 85, 63-74, 1995. 

Development of gene transfer methods into algal cells and cloning of genes for producing useful materials will extend the possibilities of microalgal CO2 mitigation. 

Williams DA, Smith FO. Progress in the use of gene transfer methods to treat genetic blood diseases. Hum Gene Ther 2000 11 2059-2066. 

Tab. 1 Gene transfer methods (vectors/delivery systenns)...

A number of clinical trials show promising results (see Table 2). In the past few years, it has become increasingly clear that for each disease, the development of a particular and specific gene transfer method in connection with a particular treatment approach will probably be necessary. The first standard use of an approved gene transfer medicinal product is to be expected within the next seven years since approximately 1% of the clinical gene therapy studies are in an advanced stage of phase II or phase III clinical trial. 

From the economic point of view, procedures for the manufacture of therapeutic DNA must be scalable and efficient, and, at the same time, simple and robust. Manufacturing processes are as manifold as the gene transfer methods used in gene therapy. As an example, manufacture of plasmid DNA for naked nucleic acid transfer can be briefly described as follows [26]. The methods available for plasmid production today largely originate from lab procedures for the production of DNA for analytical... 

The development of somatic gene therapy is still in its infancy. A number of theoretical risks of gene therapy have been listed, and numerous approaches and gene transfer methods are being developed in the clinic, even more in preclinical experiments. 

Lauer U, Burgelt E, Squire Z, Messmer K, Hofschneider PH, Gregor M, Delius M. Shock wave permeabilization as a new gene transfer method. Gene Ther 1997 4 710-715. 

Hand-held devices similar in principle to the original Biolistics and AcceU instruments are also in use. The most widely-used device is the Biolistics apparatus marketed by Bio-Rad, Inc., but Accell-based methodology has been particularly useful in developing variety-independent gene transfer methods for the more recalcitrant cereals and legumes. Detailed descriptions of the various acceleration devices, principles of operation, and other details may be found in the primaiy references. 

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