Transfection conjugates

Biju, V, Muraleedharan, D., Nakayama, K, Shinohara, Y., Itoh, T., Baba, Y. and Ishikawa, M. (2007) Quantum dot-insect neuropeptide conjugates for fluorescence imaging, transfection, and nucleus targeting of living cells. Langmuir, 23, 10254-10261. 

Zhou L, Erickson RR, Hardwick JP, Park SS, Wrighton SA, et al. 1997a. Catalysis of the cysteine conjugation and protein binding of acetaminophen by microsomes from a human lymphoblast line transfected with the cDNAs of various forms of human cytochrome P450. J Pharmacol Exp Ther 281 785-790. 

Rejman J, et al. Characterization and transfection properties of lipoplexes stabilized with novel exchangeable polyethylene glycol-lipid conjugates. Biochim Biophys Acta 2004 1660 41. 

Based on the intrinsic mitochondriotropism of dequalinium and its unique self-assembly behavior, we have developed a strategy for direct mitochondrial transfection (47-49), which involves the transport of a DNA-mitochondrial leader sequence (MLS) peptide conjugate to mitochondria using DQAsomes, the liberation of this conjugate from the cationic vector upon contact with the mitochondrial outer membrane followed by DNA uptake via the mitochondrial protein import machinery. We have demonstrated that DQAsomes fulfill all essential prerequisites for a mitochondria-specific DNA delivery system they bind and condense pDNA (24), protect it from... 

The ability of the series to induce beta-galactosidase transgene expression in COS-7 cells was measured and compared with Lipofectin (quaternary ammonium salt lipid). The transfection activity of the bile acid conjugates ranged from low (38%) in product 2c to 1000% in product 4c, as compared to Lipofectin , which was ranked as 100%. The in vitro success of these unusual cationic facial amphiphiles is inspiring for the development of more efficient chemical methods based on tissue/cell targeting enabled by the polar face of the amphiphile. 

Chloroquine drastically improves the transfection of cells when DNA/polylysine conjugates are used (Zenke et al., 1990 Midoux et al., 1993). So far, the mechanism of action of chloroquine has not been completely elucidated. Chloroquine is supposed to protect the internalized plasmid from intracellular degradation as a result of the neutralization of acidic compartments and the inhibition of endosome fusion with lysosomes. Furthermore, the swelling of vesicles can be induced when the concentration of chloroquine is high enough. However, there is no direct relationship between the neutralization of the acidic cell compartments and the transfection efficiency (Erbacher et al., 1996a). Once taken up by the cells, chloroquine accumulates inside acidic vesicles where it can reach a concentration more than 50 mM, based on the estimated volume of the vesicular compartments. At physiological pH, 82% of chloroquine is protonated and can bind to nucleic acids. Therefore, the interaction of chloroquine with DNA appears to be... 

Artificial peptides, such as GALA and JTS-1, and the sequence of the /V-terminal segment of VP1 of HRV2 rhinovirus, have also been found to enhance the transfection efficiency of polylysine conjugates/ DNA complexes (Table 16.1). These peptides, which contain acid residues (mainly glutamate) were shown to induce membrane fusion and permeabilization at pH lower than 6. Permeabilization and fusion activities... 

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