Polymer micelle complex including nucleic acid
It is an object of the present invention to provide a polyion complex used as a non-viral gene vector, which achieves sufficiently high gene expression efficiency to a target cell. The polyion complex of the present invention comprises a block copolymer formed by binding polyethylene glycol to polycation via a disulfide group and a nucleic acid.
1. A polyion complex, which comprises a block copolymer formed by binding polyethylene glycol to a polycation via a disulfide group, and a nucleic acid, wherein the block copolymer is represented by the following general formula (1):
wherein each of R 1 and R 2 independently represents a a methyl group; R 3 represents —NH—(CH 2 ) 2 —NH—(CH 2 ) 2 —NH 2 ; L 1 represents —(CH 2 ) 2 —NH—
—(CH 2 ) p1 —NH— (4);
m1 represents an integer between 30 and 150; m2 represents an integer of 1; and n represents an integer between 100 and 400.
2. The polyion complex according to claim 1 , wherein m1 represents an integer of 100; and n represents an integer of 227.
3. The polyion complex according to claim 1 , wherein the polycation portion in the block copolymer and the nucleic acid bind to each other by electrostatic interaction.
4. The polyion complex according to claim 1 , wherein the nucleic acid and the polycation portion in the block copolymer form a core portion, and a portion containing polyethylene glycol in the block copolymer forms a shell portion around the core portion.
5. A device for delivering a nucleic acid into a cell, which comprises the polyion complex according to claim 1 .
6. A method for delivering a nucleic acid into a target cell, which comprises:
administering a solution that contains the polyion complex according to any one of claims 1 to 4 to a test animal so that the polyion complex can be introduced into the target cell;
transferring the polyion complex from the endosome to the cytoplasm;
dissociating the polyion complex in the cell; and
releasing the nucleic acid into the cytoplasm.
7. A block copolymer formed by binding polyethylene glycol to polycation via a disulfide group, wherein the block copolymer is represented by the following general formula (1):
wherein each of R 1 and R 2 independently represents a methyl group; R 3 represents —NH—(CH 2 ) 2 —NH—(CH 2 ) 2 —NH 2 ; L 1 represents —(CH 2 ) 2 —NH—; m1 represents an integer between 30 and 150; m2 represents an integer of 1; and n represents an integer between 100 and 400.
8. The block copolymer according to claim 7 , wherein m1 represents an integer of 100; and n represents an integer of 227.