Synthetic cationic amphiphiles for liposome-mediated DNA transfection

The compounds with efficient DNA transfection ability into eukaryotic cells were searched from various synthetic amphiphiles which have cationic heads and long saturated hydrocarbon tails. The efficiency of amphiphiles in gene transfer was examined by the transient expression of cytochrome b₅ from its cDNA in COS cells. Among various synthetic amphiphiles, including N-[1-(2,3-dioleyloxy)propyl]-N,N,N-trimethyl-ammonium chloride which is commercially available lipid, O,O'-didodecyl-N-[p-(2-trimethylammonioethyloxy)benzoyl]-(L)-glutamate bromide was highest in efficiency. The optimum condition for the amount of the amphiphile and DNA, and the incubation time were established to be 7.5-15 μg/22 mm dish and 1-10 μg/22 mm dish, and 48-72 h, respectively.