Disclosed are cationic lipid compounds and compositions of lipid aggregates for delivery of macromolecules and other compounds into cells. The compounds can be used alone or in combination with other compounds to prepare liposomes and other lipid aggregates suitable for transfection or delivery of compounds to target cells, either in vitro or in vivo. The compounds are preferably polycationic and preferably form highly stable complexes with various anionic macromolecules, particularly polyanions such as nucleic acids. These compounds have the property, when dispersed in water, of forming lipid aggregates which associate strongly, via their cationic portion, with polyanions. Also disclosed are intermediates for preparing the compound and compositions of the invention and methods of using the compounds to introduce other compounds into cells.
