Cationic lipid

Bilayer phase transitions are sensitive to the presence of solutes that interact with lipids, including multivalent cations, lipid-soluble agents, peptides, and proteins. 

S., Hamer, )., Escobedo, J., Cohen, F., Radhakrishnan, R., Dwarki, V, and ZuCKERMANN, R.N. Lipitoids — novel cationic lipids for cellular delivery of plasmid DNA in vitro. Chem. Biol. 1998, 5, 345-354. 

Subramanian G, Hjehn RP, Deming TJ, Smith GS, Li Y, Safinya CR (2000) Structure of complexes of cationic lipids and poly(glutamic acid) polypeptides a pinched lamellar phase. J Am Chem Soc 122 26-34... 

FIG. 7 Electron micrograph of cationic lipid/DNA complexes (example of striated lamellae). (Reprinted from Ref. 117, copyright 1999 Biophysical Society.)... 

FIG. 15 Cellular entry and intracellular kinetics of the cationic lipid-DNA complexes. Cationic lipid-DOPE liposomes form electrostatic complexes with DNA, and, in this case, also transferrin (Tf) is incorporated. Cellular uptake by endoc5dosis and endosomal acidification can be blocked with cytochaiasin B and bafilomycin Aj, respectively. DNA is proposed to be released at the level of endosomal wall after fusion of the carrier lipids with endosomal bilayer. This process is facilitated by the formation of inverted hexagonal DOPE phase as illustrated in the lower corner on the right. After its release to the C5doplasm DNA may enter the nucleus. (From Ref. 253. By permission of Nature Publishing Group.)... 

Plasmid DNA can be complexed electrostatically with cationic polymers. These complexes can be used for gene transfer [241]. Like the complexes of DNA with cationic lipids these complexes adhere to the cell surface with their cationic surface charges. Thereafter, they are internalized, presumably by adsorptive endocytosis. 

However, Emi et al. [50] have prepared LS with a method established in their laboratory using a solvent extraction. In particular, the method is based on the dissolution of the triglyceride (i.e., tripalmitin) and the cationic lipid in the organic solvent (i.e., dichloromethane), and on the addition of an aqueous polyvinyl alcohol (PVA)... 

In contrast, solid lipid microparticles consisting of a tripalmitin matrix and cationic lipids prepared using the micromixer-based solvent extraction process as described by Emi et al. [50] were of monomodal size, showing a narrow size distribution in the submicrometer range (Table 8.1). 

FIGURE 8.1 Percentages of DFT association to CLS containing as cationic lipid. (A) DDAB18 prepared in the presence of PVA (open diamonds) or gelatin (closed diamonds) (B) DDAB12 (open circles) or CTAB (open squares). 

Bennett, M.J., Aberle A.M., Balasubramaniam R.P., Malone, J.G., Malone, R.W., and Nantz, M.H., Cationic lipid-mediated gene delivery to murine lung correlation of lipid hydration with in vivo transfection activity, Journal of Medicinal Chemistry, 1997, 40, 4069 1078. 

Filion, M.C., and Philips, N.C., Toxicity and immunomodulatory activity of liposomal vectors formulated with cationic lipids toward immune effector cells, Biochimica et Biophysica Acta, 1997, 1329, 345-356. 

Several enveloped viruses, and some physical gene transfer techniques such as electroporation, deliver the nucleic acid into the cell by direct crossing of the cell membrane. Lipid-based, enveloped systems can do this by a physiological, selfsealing membrane fusion process, avoiding physical damage of the cell membrane. For cationic lipid-mediated delivery of siRNA, most material is taken up by endo-cytotic processes. Recently, direct transfer into the cytosol has been demonstrated to be the bioactive delivery principle for certain siRNA lipid formulations [151]. 

Lu JJ, Langer R, Chen J (2009) A novel mechanism is involved in cationic lipid-mediated functional siRNA delivery. Mol Pharmaceutics 6 763-771... 

Martin B, Sainlos M, Aissaoui A, Oudrhiri N, Hauchecome M, Vigneron JP, Lehn JM, Lehn P (2005) The design of cationic lipids for gene delivery. Curr Pharm Des 11 375-394... 

Tousignan JD, Gates AL, Ingram LA et al (2002) Comprehensive analysis of the acute toxicities induced by systemic administration of cationic lipid Plasmid DNA complexes in mice. Hum Gene Ther 11 2493-2513... 

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