Cationic lipid
Provided are a cationic lipid which facilitates the introduction of a nucleic acid into, for example, a cell or the like; a composition containing the cationic lipid and a nucleic acid; a method for introducing a nucleic acid into a cell by using a composition containing the cationic lipid and the nucleic acid; and the like. The cationic lipid is, for example, a cationic lipid represented by formula (A): formula (A): (wherein R 1 is alkenyl or the like, R 2 is alkenyl or the like, R 3 and R 4 are each alkyl, or are combined together to form alkylene, or R 3 and R 5 are combined together to form alkylene, R 5 is a hydrogen atom or the like, or is combined together with R 3 to form alkylene, X 1 is alkylene, and X 2 is a single bond or alkylene).
1. A cationic lipid represented by:
formula (C):
wherein:
R 8 is linear alkenyl having 12 to 24 carbon atoms,
R 9 is linear or branched alkyl or alkenyl, each having 8 to 24 carbon atoms,
X 3 is alkylene having 1 to 3 carbon atoms, and
R 10 is a hydrogen atom,
with the provisos that R 8 is not (Z)-octadec-9-enyl, R 9 is not (Z)-octadec-9-enyl and X 3 is not methylene at the same time,
R 8 is not (Z)-octadec-9-enyl, R 9 is not (Z)-octadec-9-enyl and X 3 is not ethylene at the same time, and
R 8 is not (Z)-octadec-9-enyl, R 9 is not octadecyl and X 3 is not methylene at the same time.
2. The cationic lipid according to claim 1 , wherein R 8 is (Z)-tetradec-9-enyl, (Z)-hexadec-9-enyl, (Z)-octadec-6-enyl, (Z)-octadec-9-enyl, (E)-octadec-9-enyl, (Z)-octadec-11-enyl, (9Z,12Z)-octadeca-9,12-dienyl, (9Z,12Z,15Z)-octadeca-9,12,15-trienyl, (Z)-icos-11-enyl, (11Z,14Z)-icosa-11,14-dienyl, or (Z)-docos-13-enyl.
3. The cationic lipid according to claim 1 , wherein R 8 is (Z)-hexadec-9-enyl, (Z)-octadec-6-enyl, (Z)-octadec-9-enyl, (9Z,12Z)-octadeca-9,12-dienyl, (Z)-icosa-11-enyl, or (11Z,14Z)-icosa-11,14-dienyl.
4. The cationic lipid according to claim 1 , wherein X 3 is methylene or ethylene.
5. A composition comprising: a cationic lipid represented by formula (C):
wherein:
R 8 is linear or branched alkenyl having 8 to 24 carbon atoms,
R 9 is linear or branched alkyl or alkenyl, each having 8 to 24 carbon atoms,
X 3 is alkylene having 1 to 3 carbon atoms, and
R 10 is a hydrogen atom, and a nucleic acid.
6. The composition according to claim 5 , wherein the cationic lipid and the nucleic acid form a complex, or a combination of a neutral lipid and/or a polymer with the cationic lipid and the nucleic acid form a complex.
7. The composition according to claim 5 , wherein the cationic lipid and the nucleic acid form a complex, or a combination of a neutral lipid and/or a polymer with the cationic lipid and the nucleic acid form a complex, and the composition comprises a lipid membrane which encapsulates the complex.
8. The composition according to claim 5 , wherein the nucleic acid is a nucleic acid which has an activity of suppressing the expression of a target gene by utilizing RNA interference (RNAi).
9. The composition according to claim 8 , wherein the target gene is a gene which is expressed in the liver, lung, kidney, or spleen.
10. A pharmaceutical composition for use in the treatment of a disease, comprising the composition according to claim 8 .
11. The pharmaceutical composition according to claim 10 , which is for intravenous administration.
12. The pharmaceutical composition according to claim 10 , wherein the disease is associated with the liver, lung, kidney, or spleen.