Herein, we report on the design and synthesis of a novel nontoxic cationic amphiphile N,N-di-n-tetradecyl-N-[2-[N',N'-bis(2-hydroxyethyl)amino]ethyl]-N-(2-hydroxyethyl)ammonium chloride (lipid 1) whose in vitro gene transfer efficacies in CHO, COS-1, MCF-7, and HepG2 cells are remarkably enhanced when used in combination with 30 mole percent added myristic acid. Reporter gene expression assay using p-CMV-SPORT-beta-gal reporter gene revealed poor gene transfer properties of the cationic liposomes of lipid 1 and cholesterol (colipid). However, the in vitro gene delivery efficacies of lipid 1 were found to be remarkably enhanced when the cationic liposomes of lipid 1 and cholesterol were prepared in the presence of 30 mole percent added myristic acid (with respect to lipid 1) as the third liposomal ingredient.
View Article and Find Full Text PDFIn vitro gene delivery efficacies of cationic amphiphiles 1-7 (Scheme 1) were measured by both the reporter gene expression assays in CHO, COS-1, HepG2, and MCF7 cells and by the whole cell histochemical X-gal staining of representative Chinese hamster ovary cells. Our results demonstrated that in vitro gene delivery efficiencies of cationic lipids with hydroxyalkyl headgroups are adversely affected by increased covalent distances between the hydroxyl functionality and the cationic centers. Findings in the DNase I protection experiments and transmission electron microscopic study support the notion that such compromised gene delivery efficacies may originate from poor lipid-DNA binding interactions and significantly increased lipoplex nanosizes.
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