Short-chain cationic polyamino acid and use thereof

摘要

The present invention provides a cationic polyamino acid suitable for a carrier that can form a stable complex with a nucleic acid under a physiological condition and release the nucleic acid in cells suitably. The cationic polyamino acid can associate with a nucleic acid and includes a cationic amino acid residue having a cationic group in a side chain and a hydrophobic amino acid residue having a hydrophobic group in a side chain. The cationic polyamino acid includes 1 to 20 units of the cationic amino acid residue and is represented by the following formula (1).;
The meaning of each symbol in the formula is as shown in the description.

主权项

1. A cationic polyamino acid capable of associating with a nucleic acid, the cationic polyamino acid comprising:
1 to 20 units of one or more cationic amino acid residue(s) having a cationic group in a side chain; and a plurality of hydrophobic amino acid residues having a hydrophobic group in a side chain, wherein the cationic polyamino acid has the following formula (1): where: R1 is a hydroxyl group or an unsubstituted or substituted linear or branched alkyloxy group having 1 to 12 carbon atoms, an unsubstituted or substituted linear or branched alkenyloxy group having 2 to 12 carbon atoms, an unsubstituted or substituted linear or branched alkynyloxy group having 2 to 12 carbon atoms, or an unsubstituted or substituted linear or branched alkyl-substituted imino group having 1 to 12 carbon atoms; R2 is a hydrogen atom, an unsubstituted or substituted linear or branched alkyl group having 1 to 12 carbon atoms, or an unsubstituted or substituted linear or branched alkylcarbonyl group having 1 to 24 carbon atoms; R3a, R3b, R4a, and R4b are each independently a methylene group or an ethylene group; R5a and R5b are each independently —O— or —NH—; R6a and R6b are each independently a saturated or unsaturated linear or branched aliphatic hydrocarbon group having 6 to 27 carbon atoms, an aromatic hydrocarbon group having 6 to 27 carbon atoms, or a sterol group derived from a sterol; R7a and R7b are each independently selected from the group consisting of: —NH—(CH2)p1—[NH—(CH2)q1—]r1NH2 (i); —NH—(CH2)p2—N[—(CH2)q2—NH2]2 (ii); —NH—(CH2)p3—N{[—(CH2)q3—NH2][—(CH2)q4—NH—]r2H} (iii); and —NH—(CH2)p4—N{—(CH2)q5—N[—(CH2)q6—NH2]2}2 (iv), where: p1 to p4, q1 to q6, and r1 and r2 are each independently an integer of 1 to 5; R8 is a side chain of an amino acid selected from the group consisting of lysine, ornithine, arginine, homoarginine, and histidine; m is an integer of 5 to 80; n is an integer of 0 to m; x is an integer of 1 to 20; y is an integer of 0 to x; and z is an integer of 0 to 20, with the proviso that: 1≦x+z≦20, repeating units having the groups R6a, R6b, R7a, and R7b and R8 may be bound to each other in any order, and each of R6a, R6b, R7a, R7b and R8 is arbitrarily selectable for each respective amino acid residue of the cationic polyamino acid.