Reagents for intracellular delivery of macromolecules
The present invention provides certain cationic lipids containing stigmasterol, ergosterol and cholic acid groups. Compounds of the invention are useful, either alone or in combination with other lipid aggregate-forming components (e.g., DOPE, DOSPA, DOTMA or cholesterol) for formulation into liposomes or other lipid aggregates. Such aggregates are cationic, and able to form stable complexes with anionic macromolecules, such as nucleic acids. The cationic lipids of the invention are useful in methods of transfecting cells, particularly to introduce nucleic acids into cells. The invention also related to kits for the preparation of lipid aggregates and to lipid aggregates and compositions for transfection of cells.
1. A compound having the structure
and salts thereof where:
m of (A) m is 1;
R is R B , where R B is a steroid selected from the group consisting of stigmasterol, ergosterol, and cholic acid;
A is A 3 where:
A 3 is —NH—CH 2 — or —CO—N—R 1 —, where A 3 is —NH—CH 2 — when R is cholic acid and A 3 is —CO—N—R 1 — when R is stigmasterol or ergosterol; where R 1 is an alkyl, alkenyl, alkynl, alkoxy, acyl or alkylthio having from 1 to about 24 carbon atoms; and
where Z is selected from the group consisting of Z 1 -Z 15 or Z 18 ; where:
Z 1 is H;
Z 2 is —(CH 2 ) n —X, where n is 1-24 and X is selected from the group consisting of Br, Cl, I and F;
Z 3 is —(CH 2 ) n —NH 2 , n=1-24;
Z 4 is —CH 2 —NH—(CH 2 ) 3 —NH—(CH 2 ) 4 —NH 2 ;
Z 5 is —CH 2 —NH—(CH 2 ) 3 —NH—(CH 2 ) 3 —NH—(CH 2 ) 3 —NH 2 ;
Z 6 is —CH 2 —NH—(CH 2 ) n —NH 2 , n=2-24;
Z 7 is -L-X where L is selected from the group consisting of branched or straight chain alkyl, alkenyl, cycloalkyl, aryl, alkoxy, thioalkyl and thioether groups having from 1 to about 24 carbon atoms, and X is selected from the group consisting of Br, Cl, I, F, NH 2 and [(NH 2 )—(CH 2 ) n ] m where n is 2-24 and m is 1-24;
Z 8 is
Z 9 is
where n=1-24, D is H or other groups attached by amide or alkyl amino groups;
Z 10 is a reporter molecule;
Z 11 is a protein, peptide or polypeptide;
Z 12 is a polysaccharide;
Z 13 is an amine or halide reactive group;
Z 14 is
Z 15 is
n=1-24, D is H or other groups attached by amide or alkyl amino groups; and
Z 18 is a nucleic acid binding substance.
2. The compound of claim 1 wherein A 3 is —CO—N—R 1 — and R B is stigmasterol.
3. The compound of claim 1 where A 3 is —CO—N—R 1 — and R B is ergosterol.
4. A composition for transfecting a cell with a nucleic acid which comprises a nucleic acid and one or more compounds according to claim 1 .
5. A lipid aggregate which comprises one or more compounds of claim 1 .
6. A kit for preparing a lipid aggregate comprising one or more compounds according to claim 1 .
7. A method for transfecting a cell comprising the step of contacting the cell with a lipid aggregate comprising a nucleic acid and a compound according to claim 1 .
8. A composition for transfecting a cell with a nucleic acid which comprises a compound according to claim 1 capable of complexing said nucleic acid to be transfected into said cell, and a transfection-enhancing agent selected from the group consisting of an enveloped virus, a membrane virus, a viral component, and a non-viral fusagenic compound.
9. A composition according to claim 8 wherein said transfection-enhancing agent is an enveloped virus, and wherein said enveloped virus is an alphavirus.
10. A composition according to claim 9 wherein said alphavirus is Semliki Forest virus.
11. A composition according to claim 8 wherein said transfection-enhancing agent is a viral component and wherein said viral component is selected from the group consisting of viral proteins, envelope fusion peptides, viral spike glycoproteins, viral peptides of viral spike glycoproteins, and viral envelope fragments containing embedded vial protein.
12. A composition according to claim 8 wherein said transfection-enhancing agent is a non-viral fusagenic peptide.
13. A method for transfecting a cell comprising the steps of contacting the cell with a transfection composition of claim 8 .