Patent ID: 7678415

Claim:
A method for coating a complex of a nucleic acid and a liposome with closed vesicles of a lipid bilayer, the liposome comprising cationic lipid, the complex obtained by mixing the nucleic acid and the liposome in water, which consists of the steps of (i) and (ii): (i) suspending the complex in an aqueous solution consisting essentially of: water, polar organic solvent(s) selected from an alcohol, a glycol and a polyalkylene glycol, and lipid(s) selected from phospholipid, glyceroglycolipid, sphingoglycolipid, cholesterol and synthetic lipid, excluding a cationic lipid, wherein the complex has a diameter of 10 nm to 1,000 nm, and wherein the lipid(s) is dissolved in the aqueous solution; and (ii) adding water to the aqueous solution in which the complex is suspended, so as to decrease the vol % concentration of the polar organic solvent(s) in the aqueous solution, whereby the complex is coated with closed vesicles of the lipid bilayer formed of the lipid(s).