Patent ID: 7531693

Claim:
A lipid having the formula: wherein X 1 is selected from the group consisting of (CH 2 ) n , (CHOH) n , —NH—, —O—, a polyether, an ester linkage —S—, CONH, NHCO, a polyamide —NHCONH—, and NHC (═NH) NH, Y 1 is selected from the group consisting of (CH 2 ) n , a polyether, NHCO, —CO—, and a polyamide, Y 2 is selected from the group consisting of (CH 2 ) n , —NH—, —O—, a polyether, an ester linkage, —S—, CONH, NHCO, a polyamide —NHCONH—, and NHC (═NH) NH, Z 1 and Z 2 are independently selected from the group consisting of primary alkylamine, secondary alkylamine, tertiary alkyl amine, quaternary alkylamine, alkyl amino alcohol, alkyl polyamine, spermidine, spermine, carboxy spermine, guanidinium, pyridinium, pyrollidinium, piperidinyium amino acyl, peptidyl, and protein, R 8 and R 9 are independently selected from the group consisting of straight chain C 1 -C 20 alkyl, branched alkyl, cycloalkyl, straight chain alkenyl, branched alkenyl, cyclo alkenyl, and optionally substituted aryl, wherein said optional substitution, when present, comprises at least one functional group selected from the group consisting of —OH, NH 2 , —COOH, ester, amide, alkylamino, —NHCONH—, and NHC (═NH) NH], R 10 and R 11 are independently absent or selected from the group consisting of hydrogen, straight chain C 1 -C 20 alkyl, branched alkyl, cycloalkyl, straight chain alkenyl, branched alkenyl, cyclo alkenyl, and optionally substituted aryl, wherein said optional substitution, when present, comprises at least one functional group selected from the group consisting of —OH, NH 2 , —COOH, ester, amide, alkylamino, —NHCONH—, and NHC (═NH) NH], and n=1-12.