Cationic lipids for intracellular delivery of biologically active molecules

A composition having the structure ##STR15## wherein Y.sup.1 and Y.sup.2 are the same or different and are, --O--C(O)--, or --O--;

• R.sup.1 is H, or C.sub.1 to C.sub.24 alkyl or alkenyl;
• R.sup.2 is C.sub.1 to C.sub.24 alkyl or alkenyl;
• R.sup.3 and R.sup.4 are the same or different and are C.sub.1 to C.sub.24 alkyl, or H;
• R.sup.5 is C.sub.1 to C.sub.24 alkyl straight chain or branched chain;
• R.sup.6 is --C(O)--(CH.sub.2).sub.m --NH--, a diaminocarboxylate ester group which is alkyl, aryl, or aralkyl, or --C(O)--(CH.sub.2).sub.m --NH-- linked to said diaminocarboxylate ester group, or is absent;
• R.sup.7 is H, spermine, spermidine, a histone, or a protein with DNA-binding specificity, or the same groups wherein the amine functionalities of the R.sup.7 moiety are quaternized with R.sup.3, R.sup.4, or R.sup.5 groups;
• or
• R.sup.7 is an L- or D-alpha amino acid having a positively charged group on the side chain, said amino acids comprising arginine, histidine, lysine or ornithine or analogues thereof, or wherein the amine of the R.sup.7 moiety is quaternized with R.sup.3, R.sup.4 or R.sup.5 groups;
• or
• R.sup.7 is a polypeptide selected from the group consisting of L-or D-alpha amino acids, wherein at least one of the amino acids residues comprises arginine, histidine, lysine, ornithine, or analogues thereof;
• n is 1 to 8;
• m is 1 to 18;
• and
• X is a non-toxic anion.