Stable lipid-comprising drug delivery complexes and methods for their production

Abstract

Novel stable, concentrated, biologically active and ready-to-use lipid-comprising drug delivery complexes and methods for their production are described. The biological activity of the complexes produced are comparable to the formulations prepared according to the prior art admixture method and upon purification, the complexes produced by the method of this invention are 50 to 500 fold more concentrated than the complexes formed by admixture. The method described herein provides for the large scale production of lipid-comprising drug delivery systems useful for gene therapy and other applications.

1 : A noncovalent nucleic acid/lipid/polycation complex having a net positive charge at pH 6.0-8.0, the complex comprising a nucleic acid, at least one cationic lipid and a polycation,
 wherein the polycation is a cationic peptide or a polypeptide comprising polylysine, polyornithine, or polyarginine, and   wherein the noncovalent complex is formed by adding a nucleic acid to a solution comprising the at least one cationic lipid and the polycation.   
     
     
         2 : The complex of  claim 1 , wherein the ratio of lipid to nucleic acid ranges from about 0.1 nmol to 200 nmol lipid per 1 μg nucleic acid. 
     
     
         3 : The complex of  claim 1 , wherein the ratio of lipid to nucleic acid ranges from about 1 nmol to about 25 nmol lipid per 1 μg nucleic acid. 
     
     
         4 : The complex of  claim 1 , wherein the polycation:nucleic acid ratio is about 0.01 μg to about 100 μg polycation to 1 μg nucleic acid. 
     
     
         5 - 11 . (canceled) 
     
     
         12 : A noncovalent nucleic acid/lipid/polycation complex having a net positive charge at pH 6.0-8.0, the complex comprising a nucleic acid, at least one cationic lipid and a polycation,
 wherein the polycation is a cationic peptide or polypeptide comprising spermine or spermidine.   
     
     
         13 : The complex of  claim 12 , wherein the complex is formed by adding a nucleic acid to a solution comprising the at least one cationic lipid and the polycation. 
     
     
         14 : The complex of  claim 12 , further comprising a neutral lipid. 
     
     
         15 : The complex of  claim 14 , wherein the neutral lipid is cholesterol or dioleoyl phosphatidylethanolamine (DOPE). 
     
     
         16 : The complex of  claim 12 , wherein the at least one cationic lipid is present as a cationic liposome, wherein the at least one cationic lipid is present in the liposome at a concentration of from about 10 to about 100 mole % of total liposomal lipid. 
     
     
         17 : The complex of  claim 16 , wherein the at least one cationic lipid is present in the liposome at a concentration of from about 20 to about 80 mole % of total liposomal lipid. 
     
     
         18 : The complex of  claim 16 , wherein the at least one cationic lipid is present in the liposome at a concentration of from about 20 to about 60 mole % of total liposomal lipid. 
     
     
         19 : The complex of  claim 12 , wherein the polycation is up to about 500 amino acids in length. 
     
     
         20 : The complex of  claim 12 , wherein the polycation is about 20 to about 100 amino acids in length. 
     
     
         21 : The complex of  claim 12 , wherein the polycation is about 20 to about 35 amino acids in length. 
     
     
         22 : The complex of  claim 12 , wherein the polycation is about 25 to about 50 amino acids in length. 
     
     
         23 : The complex of  claim 1 , wherein the polycation has a molecular weight of from 300 to 200,000 Daltons. 
     
     
         24 : A method for delivering nucleic acid to cells comprising contacting the cells with a noncovalent nucleic acid/lipid/polycation complex having a net positive charge at pH 6.0-8.0, the complex comprising a nucleic acid, at least one cationic lipid and a polycation,
 wherein the polycation is a cationic peptide or a polypeptide comprising polylysine, polyornithine, or polyarginine, and   wherein the noncovalent complex is formed by adding a nucleic acid to a purified solution comprising the at least one cationic lipid and the polycation.   
     
     
         25 - 28 . (canceled)