阅读说明：本技术 核酸投递用聚合物 (Polymers for nucleic acid delivery ) 是由 H.卡布拉尔 内田智士 宫崎拓也 于 2019-02-01 设计创作，主要内容包括：本发明提供用于投递核酸的聚合物。本发明提供选自下述均聚物(a)和嵌段共聚物(b)的聚合物：均聚物(a),其包含具有含伯胺侧链的聚缩水甘油基链；嵌段共聚物(b),其为具有含伯胺侧链的聚缩水甘油基链与聚乙二醇链的嵌段共聚物。(The present invention provides polymers for delivering nucleic acids. The present invention provides a polymer selected from the following homopolymers (a) and block copolymers (b): a homopolymer (a) comprising a polyglycidyl chain having a side chain containing a primary amine; a block copolymer (b) having a polyglycidyl chain having a side chain containing a primary amine and a polyethylene glycol chain.)

1. A polymer selected from the following homopolymers (a) and block copolymers (b):

a homopolymer (a) comprising a polyglycidyl chain having a side chain containing a primary amine;

a block copolymer (b) having a polyglycidyl chain having a side chain containing a primary amine and a polyethylene glycol chain.

2. The polymer of claim 1, wherein,

the homopolymer is represented by the following formula I,

[ chemical formula 35]

In the formula, R¹Represents a primary amine via a methylene or ester bond, R^5aAnd R^5bEach independently represents a hydrogen atom, a halogen atom or-OCOCH (NH)₂)R³A group shown, m represents 2An integer of about 5000 a to,

R³represents a hydrogen atom or a group represented by the following chemical formula 36,

[ chemical formula 36]

In the formula, R⁴Represents an optionally substituted hydrocarbon group having 1 to 20 carbon atoms or an optionally substituted heterocyclic functional group, and j represents an integer of 1 to 5.

3. The polymer of claim 2, wherein,

the primary amine via a methylene or ester bond is represented by the following chemical formula 37,

[ chemical formula 37]

In the formula, R³Represents a hydrogen atom or a group represented by the following chemical formula 38, or R³And R⁴Each independently represents the side chain structure of any amino acid in the protein, R⁶Represents a hydrogen atom or 1 or more arbitrary amino acids, k represents an integer of 1 to 5,

[ chemical formula 38]

In the formula, R⁴Represents an optionally substituted hydrocarbon group having 1 to 20 carbon atoms or an optionally substituted heterocyclic functional group, and j represents an integer of 1 to 5.

4. The polymer of claim 1, wherein,

the block copolymer is represented by the following formula II,

[ chemical formula 39]

In the formula, R¹Represents a primary amine via a methylene or ester bond, R^2aAnd R^2bEach independently represents a hydrogen atom or a group represented by the following chemical formula 40, L^1aAnd L^1bEach independently represents a linking group, m represents an integer of 2 to 5000,

[ chemical formula 40]

In the formula, R²⁰Represents a ligand molecule or-O-CH₃A group shown, L²Represents a linking group, and n represents an integer of 5 to 20000.

5. The polymer of claim 4, wherein,

the primary amine via a methylene or ester bond is represented by the following chemical formula 41,

[ chemical formula 41]

In the formula, R³Represents a hydrogen atom or a group represented by the following chemical formula 42, or R³And R⁴Each independently represents the side chain structure of any amino acid in the protein, R⁶Represents a hydrogen atom or 1 or more arbitrary amino acids, k represents an integer of 1 to 5,

[ chemical formula 42]

In the formula, R⁴Represents an optionally substituted hydrocarbon group having 1 to 20 carbon atoms or an optionally substituted heterocyclic functional group, and j represents an integer of 1 to 5.

6. The polymer according to any one of claims 2 to 5, wherein,

R¹is-CH₂NH₂or-CH₂CH₂CH₂CH₂NH₂The groups shown.

7. The polymer according to any one of claims 2 to 5, wherein,

R¹is a group represented by the following chemical formula 43,

[ chemical formula 43]

In the formula, R³Represents a hydrogen atom or a group represented by the following chemical formula 44,

[ chemical formula 44]

-CH₂-R⁴

In the formula, R⁴Represents a propyl group, an indolyl group optionally having a substituent, or a phenyl group optionally having a substituent.

8. The polymer according to any one of claims 4 to 7,

L^1aand/or L^1bis-CH₂CH₂O-is a group represented by.

9. The polymer according to any one of claims 4 to 8,

R²is a group represented by the following chemical formula 45,

[ chemical formula 45]

Wherein n represents an integer of 5 to 20000.

10. A polyion complex comprising the polymer of any one of claims 1 to 7 and a nucleic acid.

11. The polyion complex of claim 10, wherein,

the nucleic acid is RNA or DNA.

12. The polyion complex of claim 11, wherein,

the RNA is siRNA, mRNA, antisense RNA, RNA aptamer, self-replicating RNA (self-replicating RNA), miRNA (micro RNA) or long non-coding RNA (incRNA).

13. The polyion complex of claim 11, wherein,

the DNA is antisense DNA, DNA aptamer, pDNA (plasmid DNA) or MCDNA (mini circle DNA).

14. A kit for preparing a device for delivering a nucleic acid to a target cell or tissue, wherein,

the kit comprises the polymer of any one of claims 1 to 9.

15. A device for delivering a nucleic acid to a target cell or tissue comprising the polyion complex of any one of claims 10-13.

16. A method for producing a block copolymer having a polyglycidyl chain having a primary amine-containing side chain and a polyethylene glycol chain, the method comprising:

after dehydrating polyethylene glycol, epoxy ring-opening polymerization is performed to obtain a block copolymer of polyethylene glycol and a polyglycidyl chain having a side chain, and a primary amine is introduced into the side chain of the polyglycidyl chain.

17. The method of claim 16, wherein,

dehydration was carried out using toluene.

18. The method of claim 16 or 17,

the epoxy ring-opening polymerization is carried out using 1, 2-epoxy-5-hexene or epichlorohydrin.

Technical Field

The present invention is in the field of techniques related to the delivery of nucleic acids to target cells or tissues, and more particularly, the present invention relates to the use of polycationic charged polymers as carriers for nucleic acid delivery and novel polycationic charged polymers.

Background

mRNA has attracted attention as a nucleic acid drug in terms of translation of a therapeutic protein in the cytoplasm. In addition, regarding plasmid DNA, which is one of nucleic acid drugs, the superiority of mRNA over plasmid DNA has been confirmed in terms of the necessity of insertion into host genomic DNA and transport to the nucleus (for example, non-patent document 1). However, even when mRNA monomers are administered systemically, it is necessary to develop an mRNA transport carrier because they are rapidly decomposed by enzymes, are hardly taken up into cells due to negative charges derived from phosphate groups, and cause immune reactions (for example, non-patent document 2).

As one of mRNA delivery vehicles, development of polyion complex (PIC) type polymeric micelles has been advanced. For example, it has been confirmed that when a block copolymer containing polyethylene glycol and polycation is used as a carrier for transport and mRNA is added thereto, the block copolymer and the mRNA form a polymer micelle by electrostatic interaction, and the mRNA can be contained in the core (for example, non-patent document 3). Further, by using a block copolymer containing polyethylene glycol and polyamino acid as the block copolymer, inhibition of enzymatic hydrolysis of mRNA, increase in the amount of cellular uptake by charge neutralization, and high gene expression level are achieved (for example, non-patent document 3).

However, for application to living bodies, it is important to further improve the stability of polyanions, which are abundant in living bodies, against enzymatic degradation.

Disclosure of Invention

Technical problem to be solved by the invention

It is an object of the present invention to provide polymers for the delivery of nucleic acids such as RNA.

As a result of intensive studies to solve the above problems, the present inventors have succeeded in solving the above problems by designing a block copolymer comprising polyethylene glycol and polyglycidyl amine and introducing a primary amine into a side chain of a polyglycidyl chain.

Means for solving the problems

Namely, the present invention is as follows.

(1) Selected from the following homopolymers (a) and block copolymers (b):

a homopolymer (a) comprising a polyglycidyl chain having a side chain containing a primary amine;

a block copolymer (b) having a polyglycidyl chain having a side chain containing a primary amine and a polyethylene glycol chain.

(2) The polymer according to (1), wherein,

the homopolymer is represented by the following formula I,

[ chemical formula 1]

In the formula, R¹Represents a primary amine via a methylene or ester bond, R^5aAnd R^5bEach independently represents a hydrogen atom, a halogen atom or-OCOCH (NH)₂)R³M represents an integer of 2 to 5000,

R³represents a hydrogen atom or a group represented by chemical formula 2,

[ chemical formula 2]

In the formula, R⁴Represents an optionally substituted hydrocarbon group having 1 to 20 carbon atoms or an optionally substituted heterocyclic functional group, and j represents an integer of 0 to 5.

(3) The polymer according to (2), wherein,

the primary amine via a methylene or ester bond is represented by the following chemical formula 3,

[ chemical formula 3]

In the formula, R³Represents a hydrogen atom or a group represented by chemical formula 4, or R³And R⁴Each independently represents the side chain structure of any amino acid in the protein, R⁶Represents a hydrogen atom or 1 or more arbitrary amino acids, k represents an integer of 0 to 5,

[ chemical formula 4]

In the formula, R⁴Represents an optionally substituted hydrocarbon group having 1 to 20 carbon atoms or an optionally substituted heterocyclic functional group, and j represents an integer of 0 to 5.

(4) The polymer according to (1), wherein,

the block copolymer is represented by the following formula II,

[ chemical formula 5]

In the formula, R¹Represents a primary amine via a methylene or ester bond, R^2aAnd R^2bEach independently represents a hydrogen atom or a group represented by chemical formula 6, L^1aAnd L^1bEach independently represents a linking group, m represents an integer of 2 to 5000,

[ chemical formula 6]

In the formula, R²⁰Represents a ligand molecule or-O-CH₃Shown inRadical, L²Represents a linking group, n represents an integer of 5 to 20000,

(5) the polymer according to (4), wherein,

the primary amine via a methylene or ester bond is represented by the following chemical formula 7,

[ chemical formula 7]

In the formula, R³Represents a hydrogen atom or a group represented by chemical formula 8, or R³And R⁴Each independently represents a side chain of an arbitrary amino acid, R⁶Represents a hydrogen atom or 1 or more arbitrary amino acids, k represents an integer of 0 to 5,

[ chemical formula 8]

In the formula, R⁴Represents an optionally substituted hydrocarbon group having 1 to 20 carbon atoms or an optionally substituted heterocyclic functional group, and j represents an integer of 0 to 5.

(6) The polymer according to any one of (2) to (5), wherein,

R¹is-CH₂NH₂or-CH₂CH₂CH₂CH₂NH₂The groups shown.

(7) The polymer according to any one of (2) to (5), wherein,

R¹is a group represented by the chemical formula 9,

[ chemical formula 9]

In the formula, R³Represents a hydrogen atom or a group represented by chemical formula 10,

[ chemical formula 10]

-CH₂-R⁴

In the formula, R⁴Represents a propyl group, an indolyl group optionally having a substituent, or a phenyl group optionally having a substituent.

(8) The polymer according to any one of (4) to (7), wherein,

L^1aand/or L^1bis-CH₂CH₂O-is a group represented by.

(9) The polymer according to any one of (4) to (8), wherein,

R²is a group represented by the chemical formula 11,

[ chemical formula 11]

Wherein n represents an integer of 5 to 20000.

(10) A polyion complex comprising the polymer according to any one of (1) to (7) and a nucleic acid.

(11) The polyion complex according to (10), wherein,

the nucleic acid is RNA or DNA.

(12) The polyion complex according to (11), wherein,

the RNA is siRNA, mRNA, antisense RNA, RNA aptamer, self-replicating RNA (self-replicating RNA), miRNA (micro RNA) or long non-coding RNA (incRNA).

(13) The polyion complex according to (11), wherein,

the DNA is antisense DNA, DNA aptamer, pDNA (plasmid DNA) or MCDNA (minicir cle DNA).

(14) A kit for preparing a device for delivering a nucleic acid to a target cell or tissue, wherein,

the kit comprises the polymer according to any one of (1) to (9).

(15) A kit for preparing a device for delivering a nucleic acid to a target cell or tissue, wherein,

the kit comprises the polyion complex according to any one of (10) to (13).

(16) A process for producing a block copolymer having a polyglycidyl chain having a side chain containing a primary amine and a polyethylene glycol chain, wherein,

after dehydrating polyethylene glycol, epoxy ring-opening polymerization is performed to obtain a block copolymer of polyethylene glycol and a polyglycidyl chain having a side chain, and a primary amine is introduced into the side chain of the polyglycidyl chain.

(17) The method according to (16), wherein,

dehydration was carried out using toluene.

(18) The method according to (16) or (17), wherein,

the epoxy ring-opening polymerization is carried out using 1, 2-epoxy-5-hexene or epichlorohydrin.

Effects of the invention

The RNA drug can be applied to medical treatment by the invention. For example, siRNA can suppress gene expression that causes in vivo diseases, and mRNA can supply therapeutic proteins safely and continuously. In addition, the enzymolysis of RNA can be obviously inhibited, and the RNA introduction efficiency is improved.

Drawings

FIG. 1 shows the results of stability tests of polymer micelles comprising PEG-PLL, PEG-PGBA, PEG-PGMA, and PEG-PG Leu against degrading enzymes.

FIG. 2 shows the results of experiments for introducing genes into cultured cells using PEG-PLL, PEG-PGBA, and PEG-PGMA.

FIG. 3 shows the results of polyanion resistance tests in heparins using PEG-PLL, PEG-PGBA, PEG-PGMA, PEG-PGGly, PEG-PGLeu, PEG-PGTry and PEG-PGTyr.

FIG. 4 shows the results of polyanion resistance tests in heparins using PEG-PLL, PEG-PGBA, PEG-PGMA, PEG-PGGly, PEG-PGLeu, PEG-PGTry and PEG-PGTyr.

FIG. 5 shows the results of in vivo stability tests using PEG-PLL, PEG-PGBA and PEG-PGMA.

FIG. 6 shows the results of hydrolysis test using PEG-PLL and PEG-PGLeu.

FIG. 7 shows the results of toxicity tests on cultured cells using PEG-PLL and PEG-PGLeu.

FIG. 8 is a diagram showing the heat of reaction accompanying micelle formation.

FIG. 9 is a graph showing fluorescence intensities of PEG-PGTrp polymers and micelles.

FIG. 10 is a graph showing fluorescence intensities of PEG-PGTyr polymers and micelles.

FIG. 11 shows the stability of mRNA micelles against digestion in serum.

FIG. 12 shows the introduction of luciferase gene into cultured cells in mRNA micelles.

FIG. 13 is a diagram showing the retention of mRNA-containing micelles in blood.

FIG. 14 shows the introduction of luciferase gene into mRNA-containing micelles.

FIG. 15 shows the introduction of luciferase gene into mRNA-containing micelles.

FIG. 16 is a graph showing the amount of primary amine in a polymer under physiological salt conditions.

FIG. 17 is a graph showing the amount of primary amine in a polymer under physiological salt conditions.

Detailed Description

The present invention relates to a block copolymer comprising polyethylene glycol and polyglycidyl amine or a homopolymer comprising polyglycidyl amine, wherein a primary amine is introduced into a side chain of a polyglycidyl chain.

The present inventors have focused on the chemical structure of the main chain of the block copolymer. It is considered that, in a polyion complex comprising a double-stranded nucleic acid having low flexibility such as plasmid DNA and a polyamino acid having low flexibility, no change in entropy is observed before and after formation of a polymer micelle, but in a polyion complex comprising a single-stranded nucleic acid having high flexibility such as mRNA and a polyamino acid having low flexibility, movement of mRNA is greatly restricted by the polyamino acid after formation of the polymer micelle, thereby greatly reducing entropy (for example, k. hayas hi et al., macromol. rapid commu.37 (2016) 486-493.).

Therefore, the present inventors considered whether the mobility of mRNA after formation of a polymer micelle can be improved and the decrease in entropy can be reduced by a block copolymer having high flexibility. Specifically, a block copolymer having high flexibility is designed by constituting a main chain structure of a polycationic chain as a polyglycidyl chain containing ether bonds. Further, by designing a block copolymer having a small number of side chain methylene groups in the polycationic chain, the influence of the number of side chain methylene groups on the stability was confirmed. In addition, biodegradable polymers have been designed for medical applications in living bodies. Specifically, an amino acid is introduced into the side chain structure of the polyglycidyl chain via a biodegradable ester bond.

1. Polymer and method of making same

The present invention provides a polymer selected from the following homopolymers (a) and block copolymers (b):

a homopolymer (a) comprising a polyglycidyl chain having a side chain containing a primary amine;

a block copolymer (b) having a polyglycidyl chain having a side chain containing a primary amine and a polyethylene glycol chain.

The polymer of the present invention is represented by, for example, the following formula I or II.

A homopolymer (a) comprising a polyglycidyl chain having a side chain containing a primary amine:

a homopolymer represented by the following formula I:

[ chemical formula 12]

In the formula, R¹Represents a primary amine via a methylene or ester bond, R^5aAnd R^5bEach independently represents a hydrogen atom, a halogen atom or-OCOCH (NH)₂)R³M represents an integer of 2 to 5000,

R³represents a hydrogen atom or a group represented by the following chemical formula 13,

[ chemical formula 13]

In the formula, R⁴Represents an optionally substituted hydrocarbon group having 1 to 20 carbon atoms or an optionally substituted heterocyclic functional group, and j represents an integer of 0 to 5.

In the polymer represented by the formula I, examples of the primary amine via a methylene group or the primary amine via an ester bond include those represented by the following formulae:

[ chemical formula 14]

R³Represents a hydrogen atom or a group represented by the following chemical formula 15, or R³And R⁴Each independently represents the side chain structure of any amino acid in the protein, R⁶Represents a hydrogen atom or 1 or more arbitrary amino acids, k represents an integer of 0 to 5,

[ chemical formula 15]

In the formula, R⁴Represents an optionally substituted hydrocarbon group having 1 to 20 carbon atoms or an optionally substituted heterocyclic functional group, and j represents an integer of 0 to 5.

R³And R⁴For example, the side chain structure of any amino acid (for example, 20 kinds of amino acids) in a protein.

Further, in the present invention, -NHR⁶R of (A) to (B)⁶Any amino acid (e.g., 20 kinds of natural amino acids or artificial amino acids), dipeptide, tripeptide, tetrapeptide, etc. can be used. In addition, in the reaction of R⁶When the amino acid is 1 or more arbitrary amino acids, the amino acid can be added to the reaction mixture to form an amide bond.

For example, cysteine, histidine, or other basic amino acids (e.g., lysine and arginine) may be used instead of leucine and tryptophan in PGLeu and PGGTry described in the examples. When cysteine is used, a disulfide bond can be formed, and when histidine is used, endosomal escape ability can be imparted to the polymer. When a basic amino acid is used, the cationic charge can be increased. Further, a dipeptide in which tryptophan is bonded to PGLeu (PGLeu-Trp), a dipeptide in which cysteine is bonded to PGLeu (PGLeu-Cys), and a dipeptide in which histidine is bonded to PGLeu (PGLeu-His) may be used.

When any amino acid is bonded, -NHR⁶The NH moiety of (a) becomes not a primary amine, but the bonded amino acids have a primary amine, and therefore these compounds are also included in the "primary amine via an ester bond" in the present invention.

In the present invention, -NHR⁶R of (A) to (B)⁶May be mentioned- (COCR)³NH)_p-H represents a group. R³As described above. p is a repeating unit and represents an integer of 1 to 10000.

Here, as the heterocyclic functional group optionally having a substituent, for example, there may be mentioned: indole ring, pyrrolidinone group, furan ring, pyridine ring, morpholine ring, epoxy ring, purine ring, pyrimidine ring, etc.

In the formula I, examples of the halogen atom include F, Cl, Br, I and the like.

In the polymer represented by formula I, R^5aAnd R^5bBr (bromine) in the case of a primary amine via a methylene group, and-OCOCH (NH) R in the case of a primary amine via an ester bond³The structure of (1).

A block copolymer (b) having a polyglycidyl chain having a primary amine-containing side chain and a polyethylene glycol chain:

[ chemical formula 16]

In the formula II, R¹The primary amine through a methylene group or the primary amine through an ester bond is shown, and the details of these primary amines are the same as those described above.

R^2aAnd R^2bEach independently represents a hydrogen atom or a hydrophilic group. Examples of the hydrophilic group include:

a group represented by the following chemical formula 17 (e.g., polyethylene glycol):

[ chemical formula 17]

In the formula, R²⁰represents-O-CH₃A group or ligand molecule represented by, L²Represents a linking group, and n represents an integer of 5 to 20000.

R^2aAnd R^2bIn addition to the group represented by the above formula (polyethylene glycol), other hydrophilic groups (hydrophilic polymers) may be used. Examples of such hydrophilic groups include: polyethyleneimine, 2-methacryloyloxyethyl phosphorylcholine, 2-acryloyloxyethyl phosphorylcholine, N- (2-methylacrylamide) ethyl phosphorylcholine, 4-methacryloyloxybutyl phosphorylcholine, and the like.

The ligand molecule refers to a compound used for targeting a specific biomolecule, and examples thereof include antibodies, proteins, amino acids, low molecular weight drugs, and monomers of biopolymers.

In the present invention, L^1aAnd L^1bEach independently represents a linking group, and m represents an integer of 2 to 5000. The linking group represents a spacer between the blocks of the block copolymer and may, for example, represent a single bond or-CH₂CH₂A group represented by O-.

As R¹For example, may include-CH₂NH₂or-CH₂CH₂CH₂CH₂NH₂The group shown. Furthermore, R¹There may be mentioned a group represented by the following chemical formula 18:

[ chemical formula 18]

In the formula, R³Represents a hydrogen atom or a group represented by the following chemical formula 19,

[ chemical formula 19]

-CH₂-R⁴

In the formula, R⁴Represents a propyl group, an indolyl group optionally having a substituent, or a phenyl group optionally having a substituent.

R^2aAnd/or R^2bExamples thereof include groups represented by the following formulae:

[ chemical formula 20]

Wherein n represents an integer of 5 to 20000.

< As to hydrocarbon groups, substituents, etc. >

The hydrocarbon group may be saturated or unsaturated, acyclic or cyclic. When the hydrocarbon group is acyclic, it may be linear or branched. The hydrocarbyl group comprises: 1 to 20 carbon atoms (described as "C_1-20". The same applies to other carbon atoms) alkyl, C_2-20Alkenyl radical, C_2-20Alkynyl, C_4-20Alkyldienyl radical, C_6-18Aryl radical, C_7-20Alkylaryl group, C_7-20Arylalkyl radical, C_3-20Cycloalkyl radical, C_3-20Cycloalkenyl radical, C_1-20Alkoxy radical, C_6-20Aryloxy radical, C_7-20Alkylaryloxy radical, C_2-20Alkoxycarbonyl groups, and the like.

As C_1-6Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group.

As C_1-20Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group.

As C_2-20Examples of the alkenyl group include a vinyl group, an allyl group, a propenyl group, an isopropenyl group, a 2-methyl-1-propenyl group, a 2-methallyl group, and a 2-butenyl group.

As C_2-20Examples of the alkynyl group include ethynyl, propynyl and butynyl.

As C_4-20Alkyldienyl radicals, examples being 1, 3-butanediylAlkenyl groups, and the like.

As C_6-18Examples of the aryl group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an indenyl group, a biphenyl group, an anthryl group, and a phenanthryl group.

As C_7-20Examples of the alkylaryl group include an o-tolyl group, an m-tolyl group, a p-tolyl group, a 2, 3-xylyl group, a 2, 5-xylyl group, an o-isopropylphenyl group, an m-isopropylphenyl group, an p-isopropylphenyl group, and a mesityl group.

As C_7-20Examples of the arylalkyl group include a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-phenylethyl group, a phenylpropyl group, a phenylbutyl group, a phenylpentyl group, a phenylhexyl group, a methylbenzyl group, a dimethylbenzyl group, a trimethylbenzyl group, an ethylbenzyl group, a methylphenylethyl group, a dimethylphenylethyl group, and a diethylbenzyl group.

As C_3-20Examples of the cycloalkyl group include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl.

As C_3-20Examples of the cycloalkenyl group include a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclopentadienyl group, and a cyclohexenyl group.

As C_1-20Examples of the alkoxy group include methoxy, ethoxy, propoxy, butoxy, and pentyloxy.

As C_6-20Examples of the aryloxy group include a phenoxy group, a naphthoxy group, and a biphenyloxy group.

As C_7-20Examples of the alkylaryloxy group include a methylphenoxy group, an ethylphenoxy group, a propylphenoxy group, a butylphenoxy group, a dimethylphenoxy group, a diethylphenoxy group, a dipropylphenoxy group, a dibutylphenoxy group, a methylethylphenoxy group, a methylpropylphenoxy group, and an ethylpropylphenoxy group.

As C_2-20Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a 2-methoxycarbonyl group, and a tert-butoxycarbonyl group.

Specific examples of the substituent in the hydrocarbon group optionally having a substituent and the heterocyclic functional group optionally having a substituent include, for example, a halogen atom (F, Cl, Br)I), hydroxyl, thiol, nitro, cyano, formyl, carboxyl, amino, silyl, methanesulfonyl, C)_1-6Alkyl radical, C_2-6Alkenyl radical, C_2-6Alkynyl, C_3-8Cycloalkyl radical, C_6-10Aryl radical, C_1-6Alkoxy radical, C_1-7Acyl or C_2-7Alkoxycarbonyl groups, and the like.

In the present invention, a phenyl group optionally having a substituent, a heterocyclic functional group optionally having a substituent are preferable, but not limited thereto.

The molecular weight (Mn) of the polymer represented by formula I is not limited, and may be 200 to 500000, preferably 1000 to 100000.

The molecular weight (Mn) of the block copolymer represented by formula II is not limited, but may be 400 to 1400000, preferably 1000 to 144000. In each block portion, the molecular weight of the PEG portion is, for example, 200 to 200000, preferably 200 to 44000. The molecular weight of the polyglycidyl chain moiety is, for example, 200 to 500000, preferably 1000 to 100000.

2. Production of polymers

(1) Production of the Polymer represented by formula I

The method for producing the polymer represented by formula I is as follows.

A homopolymer comprising a polyglycidyl chain having a side chain is obtained by ring-opening polymerization of epoxy using tetra-n-octylammonium bromide as an initiator. The ring-opening polymerization of epoxy is not particularly limited as long as the structure having an epoxy group is used as a polymerization monomer, and examples thereof include: epichlorohydrin, 1, 2-epoxy-5-hexene, 1-allyl-2, 3-epoxypropane, epibromohydrin, 3, 4-epoxy-1-butane, 1, 2-epoxy-9-decene, 2, 3-epoxypropylpropargylether, and the like.

After polymerization, the molecular weight distribution and the degree of polymerization of the block copolymer obtained by chemical synthesis are preferably analyzed.

In addition, in order to prepare a polymer by electrostatic interaction with RNA, a primary amine is introduced into the side chain of the polyglycidyl chain of the obtained block copolymer. Introduction of a primary amine into a side chain of a polyglycidyl chain can be achieved in high yield by appropriately selecting a solvent in hydroboration amination. The thus-obtained polyglycidyl chain having a primary amine introduced into the side chain is also referred to as polyglycidyl amine.

(2) Production of Polymer represented by formula II

The method for producing the polymer represented by formula II is as follows.

In the case of chemical synthesis of a block copolymer, it is considered that water absorption of the polyethylene glycol chain as an initiator hinders polymerization. Thus, the polyethylene glycol is dehydrated by azeotropy before polymerization. Then, the ring-opening polymerization of epoxy is carried out to obtain a block copolymer comprising polyethylene glycol and a polyglycidyl chain having a side chain. In this case, the polyethylene glycol is dehydrated with toluene or the like to perform ring-opening polymerization of epoxy, thereby synthesizing a block copolymer having controlled molecular weight distribution and polymerization degree. The ring-opening polymerization of epoxy is not particularly limited as long as the structure having an epoxy group is used as a polymerization monomer, and examples thereof include: epichlorohydrin, 1, 2-epoxy-5-hexene, 1-allyl-2, 3-epoxypropane, epibromohydrin, 3, 4-epoxy-1-butane, 1, 2-epoxy-9-decene, 2, 3-epoxypropylpropargylether, and the like.

After polymerization, the molecular weight distribution and the degree of polymerization of the block copolymer obtained by chemical synthesis are preferably analyzed.

In order to produce a polymer micelle by electrostatic interaction with RNA, a primary amine is introduced into the side chain of the polyglycidyl chain of the obtained block copolymer. Introduction of a primary amine into a side chain of a polyglycidyl chain can be achieved in high yield by appropriately selecting a solvent in hydroboration amination. The thus obtained polyglycidyl chain having a primary amine introduced into the side chain thereof is also referred to as polyglycidyl amine.

In the present invention, specific examples of the polymer represented by the formula II include polymers described in production examples 2 to 7 described later.

3. Polyion complexes

The polyion complex (polymer complex) of the present invention is a complex of a polymer compound obtainable by mixing a nucleic acid and the polymer of the present invention in a buffer solution, and is also referred to as polyion complex (PIC) or polyion complex-type polymer micelle (PIC micelle).

In the case where the polymer forming the polyion complex of the present invention is a block copolymer comprising PEG and polyglycidylamine, the nucleic acid and polycationic moiety electrostatically interact to form a core moiety, the outside of which is coated with PEG.

The polymer complex of the present invention can be easily prepared, for example, by mixing a nucleic acid and a polymer in an arbitrary buffer solution.

The size of the PIC of the present invention is, for example, 60 to 80nm in particle size by dynamic light scattering measurement (DLS).

The mixing ratio of the polymer and the nucleic acid is not limited, and for example, the ratio (N/P ratio) of the total number (N) of cationic groups (for example, amino groups) in the block copolymer to the total number (P) of phosphate groups in the nucleic acid is preferably 1 to 30, more preferably 1 to 10, and still more preferably 1 to 3.

As a specific example of the production method, reference may be made to the synthetic diagrams described in the examples below.

In the polyion complex of the present invention, the function as a nucleic acid delivery carrier can be evaluated by using the stability in serum and the protein translation efficiency as indexes. Further, evaluation of the stability of polyanions abundantly present in vivo or the function as a carrier for delivery in an in vivo (in vivo) environment can be carried out by using the retention in blood as an index.

In another embodiment of the present invention, in order to design a biodegradable delivery vehicle for clinical use, a biodegradable block copolymer having an amino acid introduced into a side chain of a polyglycidyl chain via an ester bond can be designed. In this case, the toxicity of the polymer in the living body is reduced due to cleavage of the ester bond. Cleavage of the ester bond can be evaluated by quantifying the primary amine in the polymer under physiological salt conditions. The evaluation of the toxicity of the polymer can be carried out using living cells.

For example, in the case of a biodegradable polymer into which leucine, which is one of amino acids, is introduced, polyanions that are present in abundance in vivo and stability in serum are evaluated as functional evaluations of a carrier for transporting RNA. Here, hydrophobic interaction of the polyion complex is increased due to isobutyl in leucine.

When the stability of the micelle of the present invention in serum was evaluated, the micelle exhibited higher stability than that of a micelle composed of polylysine chains, and as a result, high translation efficiency was exhibited. In addition, from the viewpoint of also improving stability against polyanions abundantly present in vivo, it is expected that high stability is exhibited in vivo. The retention in blood in an in vivo (vivo) environment was evaluated using mRNA, which has a large problem particularly in enzyme resistance. In this case, the micelle of the present invention exhibits more excellent retention in blood than a micelle having a polylysine chain. Thus, by introducing a polyglycidyl chain having an ether bond with low strain, the resistance of mRNA in vivo to enzymatic hydrolysis is improved.

In the case of the biodegradable delivery vehicle, when the cleavage of the ester bond between the introduced polymer and the amino acid under physiological salt conditions was evaluated, it was confirmed that the primary amine involved in the hydrolysis was reduced and the toxicity to the cultured cells was reduced. In addition, when the stability of a polyanion abundantly present in vivo is evaluated, a polymer micelle composed of a biodegradable polymer into which leucine, which is one of hydrophobic amino acids, is introduced exhibits higher stability than a polymer not having isobutyl as a hydrophobic functional group. Thus, delivery vehicles having high stability and low toxicity in vivo have been successfully developed.

4. Nucleic acids

In the polyion complex of the present invention, the nucleic acid contained as a constituent of the core portion is, in one embodiment, DNA or RNA. Examples of RNA include: mRNA, siRNA (small interfering RNA), antisense nucleic acid (antisense RNA), aptamer (RNA aptamer), self-replicating RNA (self-replicating RNA), mirna (micro RNA), long non-coding RNA (incrna, long non-coding RNA), and the like. Examples of the DNA include antisense nucleic acid (antisense DNA), aptamer (DNA aptamer), pDNA (plasmid DNA), MCDNA (minicircle DNA), and the like.

The siRNA may be a substance that can suppress the expression of a target gene by RNA interference (RNAi), and examples of the target gene include a cancer (tumor) gene, an anti-apoptotic gene, a cell cycle-related gene, and a proliferation signal gene. The base length of the siRNA is not limited, and is usually less than 30 bases (for example, 19 to 21 bases).

The nucleic acid molecule such as siRNA is polyanion and thus can be bound (associated) with the side chain of the polycationic portion of the block copolymer by electrostatic interaction.

5. Kit for nucleic acid delivery device

The kit for a nucleic acid delivery device of the invention comprises a polymer of the invention. The kit can be preferably used for gene therapy using RNAi for various target cells and protein therapy using mRNA.

In the kit of the present invention, the storage state of the polymer is not limited, and a solution state, a powder state, or the like can be selected in consideration of stability (storage property), ease of use, and the like.

The kit of the present invention may contain other components in addition to the polymer. Examples of other components include: nucleic acids to be introduced into cells, various buffers for lysis, dilution, etc., a lysis buffer, various proteins, instructions for use (manual), etc., can be appropriately selected depending on the purpose of use and the type of polymer to be used.

The kit of the present invention is used for preparing a polyion complex (PIC) having a core portion of a desired nucleic acid (e.g., mRNA or siRNA) to be introduced into a target cell, and the prepared PIC can be effectively used as a means for delivering the nucleic acid to the target cell.

6. Nucleic acid delivery device

In the present invention, a nucleic acid delivery device comprising the polyion complex is provided. The delivery device of the present invention can be used to prepare a nucleic acid, which is difficult to deliver in a stable state into a target cell, into a stabilized state in which the resistance to enzymatic hydrolysis is improved.

The delivery device of the present invention is applicable to various animals such as humans, mice, rats, rabbits, pigs, dogs, cats and the like, without limitation. The administration method to the animal to be tested is generally a non-oral method such as intravenous drip, and the respective conditions such as the dose amount, the number of times of administration, and the administration period can be appropriately set according to the type and state of the animal to be tested.

The delivery device of the present invention can be used in therapy (gene therapy) for introducing a desired nucleic acid into cells causing various diseases. Accordingly, the present invention can also provide a pharmaceutical composition for the treatment of various diseases containing the polymer, a gene therapeutic agent for various diseases containing the pharmaceutical composition as an active ingredient, and a method for the treatment of various diseases (particularly, a gene therapy method) using the PIC.

The method and conditions of administration are the same as described above. Examples of the various diseases include, but are not particularly limited to, cancers (e.g., lung cancer, pancreatic cancer, brain cancer, liver cancer, breast cancer, colon cancer, neuroblastoma, bladder cancer, etc.), cardiovascular diseases, motility diseases, central nervous system diseases, and the like.

For the pharmaceutical composition, excipients, fillers, extenders, binders, wetting agents, disintegrants, lubricants, surfactants, dispersing agents, buffers, preservatives, solubilizers, preservatives, flavoring agents, soothing agents, stabilizers, tonicity agents and the like, which are generally used in the manufacture of medicaments, can be appropriately selected and used, and the preparation can be carried out by a conventional method. The form of the pharmaceutical composition is usually provided in the form of an intravenous injection (including drip injection), for example, in the form of a unit dose ampoule or a multi-dose container.