Patent ID: 8541628

Claim:
A method of delivering an anionic molecule into a cell, comprising: (a) forming a lipid complex by contacting the anionic molecule with a composition comprising an effective amount of a compound according to the formula: wherein R 1 and R 2 are identical and are selected from the group consisting of C 14 H 29 and C 12 H 25 ; R 3 and R 4 are independently H; linear or branched, unsubstituted or substituted C 1-23 alkyl, acyl, alkenyl, or C 1 -C 5 heteroalkyl group having one heteroatom; or a cyclic or aryl group comprising from 0 to 5 heteroatoms wherein said heteroatoms are not the first atoms in said heteroalkyl, cyclic and aryl groups, wherein the substituent groups are selected from the group consisting of —O—(CH 2 ) k —CH 3 , —S—(CH 2 ) k —CH 3 , and X—(CH 2 ) k —, wherein X is a halide, and k is 0 to 4; R 5 has the structure wherein Z is selected from the group consisting of NR 1 , NH, and Se; R 6 is selected from the group consisting of H, R 3 , and R 4 , or when Z is NH, or NR 1 , R 6 can be an amino acid, peptide, polypeptide, protein, or mono-, di- or polysaccharide and wherein Z is NH, or NR 1 , contained therein said amino acid, peptide, polypeptide, protein, or mono-, di- or polysaccharide; n is 1 to 6; m is 1 to 10; Y is a pharmaceutically acceptable anion; and (b) contacting a cell with the lipid complex formed in step (a); whereby a biologically effective amount of the anionic molecule is delivered into the cell.