A CONCENTRATED AND STABLE AEROSOL FORMULATION OF CATIONIC LIPID - DNACOMPLEXES GIVING HIGH-LEVEL GENE-EXPRESSION IN MOUSE LUNG

Advances in gene therapy vectors and techniques hold promise for treat ment of many inherited and acquired diseases, For lung indications, es pecially those involving the epithelium, delivery of the gene therapy vehicle ideally will involve the use of an aerosol, Aerosol delivery o f transgenes using cationic lipids is currently limited by the ability to generate highly concentrated formulations of lipid:DNA complexes t hat are stable and retain their activity following aerosolization, We have examined many of the variables inherent in aerosolizing cationic lipid gene delivery vehicles and have devised a new formulation that i ncorporates small amounts of a polyethylene glycol-containing lipid, T his formulation has allowed the preparation of concentrated dispersion s of cationic lipid:plasmid DNA (pDNA) complexes (>20 mM pDNA) at appr oximately 10-fold higher concentrations than previously reported, Most of the pDNA in these formulations was bound to the lipid component an d thereby protected from nebulizer-induced shearing; the pDNA also mai ntained full biological activity both in vitro and in vivo, This new f ormulation thus represents a significant improvement over current meth ods to prepare concentrated, active cationic lipid gene delivery vecto rs, and provides a new tool with which to test gene transfer to the lu ng.