Efficient gene transfer with less cytotoxicity by means of cationic multilamellar liposomes.

A simple procedure for the preparation of cationic multilamellar vesicles (MLV) consisting of N-(alpha-trimethylammonioacetyl)-didodecyl-D-glutamate chloride, dilauroyl phosphatidylcholine, and dioleoyl phosphatidylethanolamine in a molar ratio of 1:2:2 was devised. When bacteriophage lambda DNA was encapsulated into these liposomes, entrapment efficiency was found to be nearly 100%, and digestibility of the DNA was less than 10%. Upon encapsulation of the plasmid pCH110 into cationic MLV, efficient expression was comparable to that obtained with cationic vesicles prepared by reverse-phase evaporation method (REV). Cytotoxicity of the present liposomes was less than that of cationic REV and far less than that of Lipofectin.