Abstract: Novel lipid-nucleic acid particulate complexes which are useful for in vitro or in vivo gene transfer are described. The particles can be formed using either detergent dialysis methods or methods which utilize organic solvents. Upon removal of a solubilizing component (i.e., detergent or an organic solvent) the lipid-nucleic acid complexes form particles wherein the nucleic acid is serum-stable and is protected from degradation. The particles thus formed have access to extravascular sites and target cell populations and are suitable for the therapeutic delivery of nucleic acids.

Abstract: Particle aggregation of lipid:nucleic acid complex particles is prevented by incorporating a non-cationic lipid into lipid:nucleic acid complex particles containing a cationic lipid and a nucleic acid polymer. The non-cationic lipid is a polyethylene glycol-based polymer.

Abstract: Novel lipid-nucleic acid particulate complexes which are useful for in vitro or in vivo gene transfer are described. The particles can be formed using either detergent dialysis methods or methods which utilize organic solvents. Upon removal of a solubilizing component (i.e., detergent or an organic solvent) the lipid-nucleic acid complexes form particles wherein the nucleic acid is serum-stable and is protected from degradation. The particles thus formed have access to extravascular sites and target cell populations and are suitable for the therapeutic delivery of nucleic acids.

Abstract: Particle aggregation of lipid:nucleic acid complex particles is prevented by incorporating a non-cationic lipid into lipid:nucleic acid complex particles containing a cationic lipid and a nucleic acid polymer. The non-cationic lipid is a polyethylene glycol-based polymer.

Abstract: Novel lipid-nucleic acid particulate complexes which are useful for in vitro or in vivo gene transfer are described. The particles can be formed using either detergent dialysis methods or methods which utilize organic solvents. Upon removal of a solubilizing component (i.e., detergent or an organic solvent) the lipid-nucleic acid complexes form particles wherein the nucleic acid is serum-stable and is protected from degradation. The particles thus formed have access to extravascular sites and target cell populations and are suitable for the therapeutic delivery of nucleic acids.

Abstract: Methods of forming cationic liposome/nucleic acid complexes in which the complexes have a mean diameter of about 200 to about 300 nm are provided. The complexes are formed by combining a first solution of preformed cationic unilamellar liposomes with a mean diameter of from 100 to 150 nm, with a second solution of nucleic acid. Each of the solutions are equilibrated prior to mixing to temperatures of from 0.degree. C. to about 12.degree. C., preferably about 2.degree. C. to about 7.degree. C. The preformed cationic liposomes are typically prepared from an unsaturated cationic lipid, for example DODAC, DOTAP, DOTMA, DODAP, DMRIE, DORI, DOSPA and combinations thereof, and a neutral lipid, for example DOPE or cholesterol. The combination of the first and second solutions is typically carried out by gentle mixing over ice for a period of time of from about 10 to about 60 minutes.

Abstract: Novel, hydrophobic lipid-nucleic acid complexes. The complexes are charge-neutralized and contain the nucleic acid in a non-condensed form. Manipulation of these complexes in either detergent-based or organic solvent-based systems leads to particle formation. Thus, the present invention also provides methods of preparing lipid-nucleic acid particles which are useful for the therapeutic delivery of nucleic acids. The particles are constructed via hydrophobic lipid-nucleic acid intermediates (or complexes). Upon removal of a solubilizing component (i.e., detergent or an organic solvent) the nucleic acid forms a particle with lipids and is protected from degradation. The particles thus formed are suitable for use in intravenous nucleic acid transfer as they are stable in circulation, of a size required for pharmacodynamic behavior resulting in access to extravascular sites and target cell populations.