阅读说明：本技术 高分子化合物及使用了该高分子化合物的细胞内化合物导入促进剂 (Polymer compound and intracellular compound introduction promoter using same ) 是由 佐久间信至 鹈川真实 高日俊辅 福岛一范 武藤美音 宫田康平 田崎晃子 松本萤 于 2019-07-11 设计创作，主要内容包括：本发明的目的在于提供一种通用性高、安全性更高的药物的膜穿透促进技术。所述技术问题能够通过本发明的高分子化合物解决,所述高分子化合物的分子量为1000以上,且其侧链的末端具有一个精氨酸或者具有含一个以上精氨酸且链长为2～6的碱性肽,并且含有0.5～20mmol/g来自于精氨酸的胍基。(The purpose of the present invention is to provide a membrane penetration promoting technique for a drug which has high versatility and higher safety. The polymer compound has a molecular weight of 1000 or more, has one arginine or a basic peptide having 2 to 6 chain lengths and containing one or more arginines at the end of a side chain, and contains 0.5 to 20mmol/g of a guanidine group derived from arginine.)

1. A polymer compound having a molecular weight of 1000 or more, having one arginine or a basic peptide having 2 to 6 chain lengths and containing one or more arginines at the end of a side chain, and containing 0.5 to 20mmol/g of a guanidino group derived from arginine.

2. The polymer compound according to claim 1, wherein the main chain of the polymer compound is one or a combination of two or more selected from the group consisting of a hydrophilic polymer, an anionic polymer, and a polysaccharide derivative.

3. The polymer compound according to claim 1 or 2, wherein the arginine or the basic peptide is terminated with-CONH₂And (4) a base.

4. The polymer compound according to any one of claims 1 to 3, wherein the basic peptide is composed of arginine and glycine.

5. A cell-specific compound introduction promoter comprising the polymer compound according to any one of claims 1 to 4.

6. A pharmaceutical composition comprising the polymer compound according to any one of claims 1 to 4 and a drug.

Technical Field

The present invention relates to a polymer compound and an intracellular compound introduction promoter using the same. According to the present invention, a compound such as a drug can be efficiently introduced into a cell.

Background

Biopharmaceuticals such as peptides, proteins, antibodies, and nucleic acids have extremely high specificity for target molecules causing diseases, and are considered to be effective for the treatment of diseases. About half of the new drugs marketed in 2015 are biological drugs, and are expected to increase further in the future. Examples of the pharmacokinetic properties of the biopharmaceutical include low membrane permeability. Due to the above-mentioned properties resulting from high water solubility and high molecular weight, many biopharmaceuticals have been developed as highly invasive injections. Therefore, there are problems such as administration management by doctors, high production cost, etc. in addition to the pain of patients, and injection of biopharmaceuticals is a cause of an increase in medical costs.

However, the development of a technique for promoting membrane penetration of a drug at a local administration site, migration of the drug in the systemic blood, and promotion of absorption to effectively reach a target site is one of the main fields in the DDS research. Typical techniques include prodrugs for improving lipid solubility or for transporter recognition, but these are mainly low-molecular organic compounds and have not been successfully used in biopharmaceuticals. As a typical absorption enhancer, there is an example in which sodium caprate is used as an additive to ampicillin suppositories, but this is extremely limited. There is an ongoing need to develop a DDS technique that can improve the absorption of biopharmaceuticals, enable self administration management of patients such as oral administration or nasal administration, and control medical costs.

For the research of the HIV infection organization, a protein having high cell membrane permeability and a membrane penetration promoting technique using the protein are being researched. Specifically, as a DDS vector, research and development of a cell-penetrating peptide based on the primary structure of the HIV viral protein have been actively conducted. The membrane-penetrating peptide is a side chain oligopeptide of about 10 residues rich in basic amino acids such as arginine and lysine, and as a representative membrane-penetrating peptide, oligoarginine, Penetratin, and the like are known.

The present inventors have disclosed a polymer compound and a polysaccharide derivative which are applied to a cell-penetrating peptide technique and which can introduce a water-soluble polymer substance such as a nucleic acid or a protein, or a drug into a cell or a mucosal membrane easily and efficiently (patent documents 1 and 2). By using these high molecular weight compounds and polysaccharide derivatives, the low membrane-permeability compounds can be efficiently introduced into cells or mucous membranes without complicated pretreatment.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2016/136707

Patent document 2: international publication No. 2016/136708

Disclosure of Invention

Technical problem to be solved by the invention

The polymer compounds and polysaccharide derivatives described in patent documents 1 and 2 are expensive in the form of a cell-penetrating peptide having a chain length of 8 amino acids as the center or a longer-chain cell-penetrating peptide, and it is difficult to develop the peptide into a pharmaceutical additive unless the cost is reduced.

In addition, since it still has little toxicity, it is desired to develop a membrane penetration promoting technique of a drug which is safer for cells.

The purpose of the present invention is to provide a membrane penetration promoting technique for a drug which has high versatility and higher safety.

Means for solving the problems

The present inventors have conducted extensive studies on a technique for promoting membrane penetration of a highly safe drug, and as a result, have surprisingly found that the above-mentioned technical problems can be solved by a polymer compound containing a basic peptide having a chain length of 6 or less amino acids at the end of a side chain.

The present invention has been completed based on this finding.

Namely, the present invention relates to:

[1] a polymer compound having a molecular weight of 1000 or more, having one arginine or a basic peptide containing one or more arginines and having a chain length of 2 to 6 at the end of a side chain thereof, and containing 0.5 to 20mmol/g of a guanidino group derived from arginine;

[2] the polymer compound according to [1], wherein a main chain of the polymer compound is one or a combination of two or more selected from the group consisting of a hydrophilic polymer, an anionic polymer and a polysaccharide derivative;

[3]according to [1]Or [2]]The polymer compound wherein the arginine or basic peptide is terminated with-CONH₂A group;

[4] the polymer compound according to any one of [1] to [3], wherein the basic peptide is composed of arginine and glycine;

[5] a cell-specific compound introduction promoter comprising the polymer compound according to any one of [1] to [3 ]; and

[6] a pharmaceutical composition comprising the polymer compound according to any one of [1] to [3] and a drug.

The present specification discloses:

[7] a method for administering a drug, which comprises a step of mixing the polymer compound according to any one of [1] to [4] with a drug (particularly a low-membrane-permeability drug), and a step of administering an effective amount of the drug to a subject;

[8] use of the polymer compound according to any one of [1] to [4] for administration of a drug (particularly, a low membrane permeability drug);

[9] use of the polymer compound according to any one of [1] to [4] for producing a pharmaceutical composition.

Effects of the invention

According to the polymer compound of the present invention, the effect of the present invention can be obtained even when the basic peptide of the side chain has a chain length of 6 or less amino acids, for example, 1 amino acid, and therefore, the compound introduction promoter can be produced at a lower cost than a conventional long-chain cell-penetrating peptide such as an octaamino acid. Further, the polymer compound of the present invention can be safely introduced because it can efficiently introduce a compound such as a drug into a cell and has low cytotoxicity.

Detailed Description

[1] Polymer

The polymer compound has a molecular weight of 1000 or more, has one arginine or a basic peptide containing one or more arginines and having a chain length of 2 to 6 at the end of a side chain, and contains 0.5 to 20mmol/g of a guanidine group derived from arginine.

< molecular weight > <

The molecular weight of the polymer compound is not particularly limited as long as the effect of the present invention can be obtained, and the lower limit is, for example, 1000 or more, preferably 5000 or more, more preferably 1 ten thousand or more, further preferably 5 ten thousand or more, further preferably 10 ten thousand or more, further preferably 20 ten thousand or more, and further preferably 30 ten thousand or more. The upper limit of the molecular weight is, for example, 5000 ten thousand or less, preferably 4000 ten thousand or less, more preferably 3000 ten thousand or less, further preferably 2000 ten thousand or less, and further preferably 1000 ten thousand or less. The molecular weight can be measured in any combination of the upper limit and the lower limit of the molecular weight. When the molecular weight of the polymer compound is too small or too large, the effects of the present invention may not be sufficiently obtained.

In the present specification, the molecular weight is a weight average molecular weight. The weight average molecular weight refers to a weight average molecular weight when GPC analysis is performed using an aqueous solvent, and is a weight average molecular weight in terms of pullulan, polyethylene glycol (PEG), or polyethylene oxide (PEO).

< an arginine or basic peptide >)

The polymer compound of the present invention has one arginine at the end of a side chain, or has a basic peptide having 2 to 6 chain lengths containing one or more arginines at the end of a side chain. The polymer compound of the present invention can effectively introduce a compound such as a drug into a cell by having an arginine or a basic peptide.

The basic peptide having a chain length of 2 to 6 contains at least one arginine, and the lower limit of the number of arginines is preferably 2 or more, and more preferably 3 or more. The upper limit is 6 or less, preferably 5 or less, and more preferably 4 or less. The 2 or more arginines contained in the basic peptide may be contained in the basic peptide continuously or discontinuously. The present invention can be carried out in any combination of the upper limit and the lower limit of arginine contained in the basic peptide, as long as the effect of the present invention is obtained.

The chain length of the basic peptide having a chain length of 2 to 6 is not particularly limited as long as it is a chain length of 2 to 6, and is 2 to 6 in an embodiment, 2 to 5 in an embodiment, 2 to 4 in an embodiment, 2 to 3 in an embodiment, 3 to 6 in an embodiment, 3 to 5 in an embodiment, 3 to 4 in an embodiment, 4 to 6 in an embodiment, and 4 to 5 in an embodiment. In these basic peptides, all amino acids may be arginine, or one or more amino acids other than arginine (e.g., glycine) may be contained.

The basic peptide may contain an amino acid other than arginine as long as the basic peptide is a general basic peptide. Examples of the amino acid other than arginine include basic amino acids (e.g., ornithine, lysine, hydroxylysine, or histidine), neutral amino acids (e.g., alanine, asparagine, cysteine, glutamine, glycine, isoleucine, leucine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, or valine), and acidic amino acids (e.g., aspartic acid or glutamic acid). The number of amino acids other than arginine is preferably 5 or less, more preferably 4 or less, further preferably 3 or less, further preferably 2 or less, further preferably 1 or less, and most preferably 0.

The amino acid contained in the basic peptide may be either L-type or D-type, and may be appropriately selected depending on the cell and the water-soluble high-molecular weight substance to be introduced. In addition, when an amino acid is described in the present specification, it is an α -amino acid unless otherwise specified.

Examples of the basic peptide having a chain length of 2 to 6 include RR (R represents arginine, the same applies hereinafter), RRR, RRRR, rrrrrrr, or rrrrrrrr, or a basic peptide having a chain length of 2 of a combination of 1 arginine and 1 glycine, a basic peptide having a chain length of 3 of 2 arginine and 1 glycine, a basic peptide having a chain length of 4 of 3 arginine and 1 glycine, a basic peptide having a chain length of 4 of 2 arginine and 2 glycine, a basic peptide having a chain length of 5 of 4 arginine and 1 glycine, a basic peptide having a chain length of 5 of 3 arginine and 2 glycine, a basic peptide having a chain length of 6 of 5 arginine and 1 glycine, a basic peptide having a chain length of 6 of 4 arginine and 2 glycine, or a peptide having a chain length of 6 of 3 arginine and 3 glycine. The arrangement of glycine and arginine is not particularly limited, but arginine is preferably located at the terminal of the side chain.

The basic peptide may be represented by the following general formula (1) or the following general formula (2):

[ chemical formula 1]

Wherein, X¹Represents a residue obtained by removing a terminal amino group and a terminal carboxyl group from arginine, a basic amino acid, a neutral amino acid, or an acidic amino acid, and X¹At least one of the two is an arginine residue, and a is an integer of 2-6;

[ chemical formula 2]

Wherein, X¹Represents a residue obtained by removing a terminal amino group and a terminal carboxyl group from arginine, a basic amino acid, a neutral amino acid, or an acidic amino acid, and X¹At least one of the above groups is an arginine residue, and a is an integer of 2 to 6.

The terminal of the basic peptide represented by the formula (1) is-CONH₂And (4) a base. The terminal of the basic peptide may be-COOH (carboxyl group), but the terminal may be-CONH₂Radical (or NH)₂Basal), the dispersibility of the resulting intracellular compound introduction promoter or pharmaceutical composition is improved.

< Main chain >

The main chain of the polymer compound in the present specification means a portion other than a side chain containing one arginine or a portion other than a side chain containing one or more basic peptides containing one or more arginines and having a chain length of 2 to 6. Specifically, the main chain may be a one-chain main chain or a main chain obtained by graft polymerization. The main chain generally refers to the longest carbon chain within the compound, which may be partially substituted with heteroatoms. The main chain may have a ring structure having the longest line as the main chain.

The polymer compound of the present invention can be produced, for example, by bonding a side chain containing one arginine at the end or a side chain containing one or more basic peptides containing one or more arginines and having a chain length of 2 to 6 to a polymer compound or graft polymer having one chain (hereinafter, sometimes collectively referred to as a main chain polymer).

The main chain polymer is not particularly limited, and examples thereof include a hydrophilic polymer, an anionic polymer, and a polysaccharide derivative, but a hydrophilic polymer or a polysaccharide derivative is preferable. In the present specification, the hydrophilic polymer refers to a water-soluble polymer or a polymer that swells in water. The water-soluble polymer is a polymer which is uniformly dissolved in water at 25 ℃ in an amount of 0.1 mass% or more under normal pressure.

The hydrophilic polymer is not particularly limited, and examples thereof include polysaccharides or modified polysaccharides such as guar gum, agarose, mannan, glucomannan, polydextrose, lignin, chitin, chitosan, carrageenan, pullulan, chondroitin sulfate, cellulose, hemicellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, starch, cationic starch, and dextrin; water-soluble proteins or water-soluble polypeptides such as albumin, casein, gelatin, polyglutamic acid (poly-gamma-glutamic acid or poly-alpha-glutamic acid), polylysine, and the like; polyacrylic acid, polymethacrylic acid, poly (hydroxyethyl acrylate), polyacrylamide, polymethacrylamide, poly (N-vinylacetamide), polyvinylpyrrolidone, polyvinyl alcohol, poly (2-aminoethyl acrylate), poly (2-aminoethyl methacrylate), acrylic acid/acrylamide copolymer, methacrylic acid/acrylamide copolymer, acrylic acid/N-isopropylacrylamide copolymer, methacrylic acid/N-isopropylacrylamide copolymer, acrylic acid/N-vinylacetamide copolymer, methacrylic acid/N-vinylacetamide copolymer, acrylic acid/maleic acid copolymer, methacrylic acid/maleic acid copolymer, acrylic acid/fumaric acid copolymer, methacrylic acid/fumaric acid copolymer, poly (hydroxyethyl acrylate), poly (acrylamide), poly (N-vinylacetamide), poly (2-aminoethyl methacrylate), poly (, Vinyl-based hydrophilic polymers such as ethylene/maleic acid copolymers, isobutylene/maleic acid copolymers, styrene/maleic acid copolymers, alkyl vinyl ether/maleic acid copolymers, and alkyl vinyl ether/fumaric acid copolymers; water-soluble polyurethanes, and the like.

The polysaccharide derivative is not particularly limited, and examples thereof include carboxymethylated polysaccharide derivatives such as carboxymethylated starch, carboxymethylated cellulose, and carboxymethylated β -glucose, pectin, pectic acid, hyaluronic acid, and alginic acid.

The anionic polymer is a polymer having an anionic group in a side chain. The "anionic group" in the anionic polymer may be appropriately selected from the anionic groups described above for the amphoteric polymer.

As one form of the anionic group, a carboxyl group, a phosphoric acid group, a sulfonic acid group, a nitric acid group, a boric acid group are included. Specific examples of the anionic polymer are not particularly limited, and examples thereof include polyacrylic acid, polymethacrylic acid, polyglutamic acid, carboxymethylated polyhistidine, hyaluronic acid, alginic acid, and polyaspartic acid.

The main chain polymer may be one or a combination of two or more of the above hydrophilic polymer, anionic polymer and polysaccharide derivative.

In order to facilitate bonding of arginine or a basic peptide (or a side chain containing arginine or a side chain containing a basic peptide), the main chain polymer is preferably a main chain polymer having a carboxyl group or an amino group. Having a carboxyl group allows easy bonding to an amino group of an amino acid such as arginine. Further, the amino group can be easily bonded to a carboxyl group of an amino acid such as arginine.

The main chain polymer is not particularly limited, but a polymer having no film-permeability is preferable, and a polymer having no guanidine groups is preferable. It is considered that the polymer compound of the present invention itself is not easily incorporated into cells and only compounds such as drugs loosely coexisting with non-covalent bonds are easily incorporated into cells by making the backbone polymer have no guanidine groups or no membrane permeability.

< side chain >)

The side chain of the polymer compound of the present invention is not particularly limited as long as it contains one arginine or a basic peptide having a chain length of 2 to 6 and containing one or more arginines at the terminal side. That is, in the present specification, the side chain refers to a chain containing one arginine at the terminal side or a chain containing a basic peptide having a chain length of 2 to 6 and containing one or more arginines. Further, the terminal of the side chain means a terminal portion of a branch chain branching from the main chain and no longer bonded to the main chain.

The side chain containing one arginine at the terminal side and the side chain containing one or more basic peptides having a chain length of 2 to 6 at the terminal side may contain any chain at the main chain side of the arginine or the basic peptide. Any chain is not particularly limited, and examples thereof include linker peptides (linker peptides).

Examples of the amino acid constituting the connecting peptide include neutral amino acids and ω -aminoalkanoic acids. Examples of the neutral amino acid include alanine, asparagine, cysteine, glutamine, glycine, isoleucine, leucine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, hydroxyproline, and the like, and examples of the ω -aminoalkanoic acid include 3-aminopropionic acid, 4-aminobutyric acid, 5-aminopentanoic acid, 6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminocaprylic acid, 9-aminononanoic acid, 10-aminodecanoic acid, and 11-aminoundecanoic acid, and any combination thereof may be used. From the viewpoint of improving the efficiency of introducing the compound into the cells, glycine, alanine, valine, isoleucine, leucine, serine, threonine, and phenylalanine are preferable, glycine, alanine, and serine are more preferable, and glycine is most preferable.

The chain length of the linker peptide is not particularly limited as long as the effect of the present invention can be obtained, and is, for example, 1 to 30, preferably 1 to 20, more preferably 1 to 10, and still more preferably 1 to 5.

< guanidino >

The polymer compound of the present invention contains 0.5 to 20.0mmol/g, preferably 1.0 to 10.0mmol/g, more preferably 1.0 to 8.0mmol/g, and further preferably 1.5 to 8.0mmol/g of a guanidino group derived from arginine and represented by the following formula (3). If the amount is less than 0.5mmol/g, the effect of the present invention cannot be obtained, and if the amount is more than 20.0mmol/g, toxicity increases depending on the subject to be introduced. When the content of guanidino is in the above range, a compound such as a drug can be efficiently introduced into a cell.

[ chemical formula 3]

For the content of guanidino group in the polymer compound of the present invention, for example, by measuring the guanidino group content in the polymer compound¹H-NMR was performed, and hydrogen atoms derived from the main chain and hydrogen atoms derived from arginine in the polymer were measured to calculate the content of the group derived from arginine, but the present invention is not limited thereto. From the results, the density of guanidine groups per polymer compound can be calculated. The specific measurement method is as shown in examples.

< preparation method of Polymer Compound >)

The method for producing the polymer compound of the present invention is not particularly limited, and for example, the polymer compound can be produced by polymerizing a polymerizable monomer having a side chain containing one arginine or a polymerizable monomer having a side chain containing one or more basic peptides having a chain length of 2 to 6 and containing one or more arginines. The side chain may be prepared by introducing the side chain containing one arginine (for example, one arginine) or the side chain containing a basic peptide having one or more arginines and a chain length of 2 to 6 (for example, a basic peptide having one or more arginines and a chain length of 2 to 6) into the main chain polymer. However, from the viewpoint of easy preparation, it is preferable to prepare the polymer by introducing the side chain containing one arginine (for example, one arginine) or the side chain containing one or more basic peptides containing one or more arginines and having a chain length of 2 to 6 (for example, one or more basic peptides containing one or more arginines and having a chain length of 2 to 6) into the main chain polymer.

When the main chain polymer has a carboxyl group, a peptide-forming reaction is performed between an amino group of arginine or a basic peptide and the carboxyl group, whereby a polymer compound can be produced. The reaction between the carboxyl group and the amino group may be carried out by a known method, and for example, a method in which a carboxyl succinimide is esterified with an N-hydroxysuccinimide and then reacted with an amino group is mentioned.

On the other hand, when the main chain polymer has an amino group, it can be obtained by subjecting the carboxyl group of arginine or a basic peptide to a peptide-forming reaction with the amino group. The method for immobilizing the side chain containing arginine or the side chain containing a basic peptide having a chain length of 2 to 6 and containing at least one arginine is not limited to this method, and immobilization can be performed by a generally known chemical reaction.

When the main chain polymer is a main chain polymer having a side chain having a carboxyl group or an amino group at the end, the polymer compound of the present invention can also be produced by bonding one arginine or a basic peptide having 2 to 6 chain lengths and containing one or more arginines to the carboxyl group or the amino group.

The polymer compound of the present invention can be used for the preparation of a compound introduction promoter or a pharmaceutical composition described later. Therefore, the use of the present invention is an application for producing a compound introduction promoter or a drug for treating or preventing a disease.

[2] Compound introduction accelerator

The compound introduction promoter of the present invention contains the polymer compound of the present invention. By containing the polymer compound, a compound such as a drug can be efficiently introduced into a cell.

< Compound introduced into cells >)

The compound to be introduced into a cell by the compound introduction promoter of the present invention is not particularly limited, and examples thereof include proteins (peptides), DNA, RNA, lipids, sugars, and low molecular weight compounds. In particular, it is useful for introducing a low membrane-permeable compound having a low introduction rate into cells.

Examples of the low membrane permeability compound include peptide/protein drugs such as insulin and insulin secretion promoters (e.g., Exendin-4 and GLP-1), steroid hormones, non-steroidal analgesic and anti-inflammatory agents, psychotropic agents, antihypertensive agents, ischemic heart disease therapeutic agents, antihistamines, anti-asthmatic agents, anti-parkinson agents, cerebral circulation improving agents, antiemetics, antidepressants, antiarrhythmics, anticoagulants, anti-gout agents, antifungal agents, anti-dementia agents, sjogren syndrome therapeutic agents, narcotic analgesics, beta receptor blockers, beta 1 receptor agonists, beta 2 receptor agonists, parasympathetic nerve agonists, antitumor agents, diuretics, antithrombotic agents, histamine H1 receptor antagonists, histamine H2 receptor antagonists, antiallergic agents, smoking cessation aids, vitamins; nucleic acid compounds such as deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) and analogs or derivatives thereof (e.g., Peptide Nucleic Acid (PNA), phosphorothioate DNA, and the like); peptide compounds such as enzymes, antibodies, glycoproteins, and transcription factors; polysaccharide derivatives such as pullulan, amylose, glycogen, cyclodextrin, dextran, hydroxyethyldextran, mannan, cellulose, starch, alginic acid, chitin, chitosan, hyaluronic acid, and derivatives thereof.

The cells to which the compound introduction promoter of the present invention is applied may be any of animal, plant, or bacterial cells, but from the viewpoint of the efficiency of introduction of the low membrane permeability compound, cells of a odontolite (for example, human, monkey, dog, cat, ferret, cow, horse, goat, sheep, guinea pig, hamster, gerbil, mouse, or rat) are preferable. Compounds can be introduced into cells in vivo or in vitro.

The compound introduction promoter of the present invention may contain a diluent, an additive, or the like in addition to the polymer compound. Examples of the diluent include purified water, alcohols (e.g., ethanol), distilled water for injection, physiological saline, propylene glycol, polyethylene glycol, vegetable oils (e.g., olive oil), and polysorbate 80. In addition, as an additive other than the diluent, a wetting agent, a suspending agent, a sweetener, a fragrance, or a preservative, an emulsifier, a dispersant, a stabilizer, a solubilizer, a solubilizing aid, or the like may be contained.

The compound introduction promoter of the present invention can be used for introducing a compound (particularly, a low membrane permeability compound) into a cell. That is, the application of the present invention is an application of a compound introduction promoter for introducing a compound (particularly, a low membrane permeability compound) into a cell.

[ pharmaceutical composition ]

The pharmaceutical composition of the present invention contains a drug and the polymer compound of the present invention. By containing the polymer compound, a drug can be efficiently introduced into a cell.

< medicine >

The drug contained in the pharmaceutical composition of the present invention is not particularly limited, examples of the drug include peptide/protein drugs such as insulin and insulin secretion promoters (e.g., Exendin 4 and GLP-1), steroid hormones, non-steroidal analgesic and anti-inflammatory agents, psychotropic agents, antihypertensive agents, ischemic heart disease therapeutic agents, antihistamines, anti-asthmatic agents, anti-parkinson agents, cerebral circulation improving agents, anti-emetics, antidepressants, antiarrhythmics, anticoagulants, anti-gout agents, antifungal agents, anti-dementia agents, therapeutic agents for sjogren's syndrome, narcotic analgesics, beta-receptor blockers, beta 1 receptor agonists, beta 2 receptor agonists, parasympathetic agonists, antitumor agents, diuretics, antithrombotic agents, histamine H1 receptor antagonists, histamine H2 receptor antagonists, antiallergic agents, smoking-cessation aids, and vitamins; antibody drugs, and the like.

The pharmaceutical composition of the present invention may contain a diluent, an additive, or the like in addition to the drug and the polymer compound. Examples of the diluent include purified water, alcohols (e.g., ethanol), distilled water for injection, physiological saline, propylene glycol, polyethylene glycol, vegetable oils (e.g., olive oil), and polysorbate 80. In addition, as an additive other than the diluent, a wetting agent, a suspending agent, a sweetener, a fragrance, or a preservative, an emulsifier, a dispersant, a stabilizer, a solubilizer, a solubilizing aid, or the like may be contained.

The dose of the pharmaceutical composition of the present invention can be determined as appropriate in consideration of the activity intensity of the active ingredient, symptoms, age or sex of the subject to be administered, and the like. For example, in the case of oral administration, the amount of the drug to be administered to an adult (in terms of body weight 60 kg) is usually about 0.1 to 100mg, preferably 0.1 to 50mg per day. In the case of parenteral administration, the dose is 0.01 to 50mg, preferably 0.01 to 10mg per day in the case of injection.

< method of administering drug >)

The method of administering the medicament of the present invention comprises: a step of mixing the polymer compound and a drug (particularly a low-membrane-permeability drug), and a step of administering an effective amount of the drug to a subject. The method of administering the drug of the present invention is not limited, and the drug to be administered is not particularly limited. Further, according to the method for administering a drug of the present invention, the drug can be efficiently introduced into cells.

< Polymer Compound for drug administration >

The polymer compound of the present invention is a polymer compound used for administration of a drug (particularly, a low membrane permeability drug). That is, the polymer compound of the present invention is a polymer compound for drug administration, and the polymer compound and the drug can be used without limitation. The polymer compound of the present invention enables effective administration of a drug to cells.

< application in the preparation of pharmaceutical compositions >

The application of the invention is the application of the macromolecular compound in preparing a pharmaceutical composition. In the preparation of the pharmaceutical composition, a pharmaceutical composition containing a polymer compound and a drug is prepared. In the preparation of a pharmaceutical composition, a pharmaceutical composition can be prepared according to a known method for preparing a pharmaceutical composition, in addition to using the polymer compound of the present invention.

< action >

The mechanism by which the polymer compound of the present invention can efficiently introduce a compound such as a drug into a cell is not specifically defined. However, the following inference can be made. However, the present invention is not limited by the following inference.

The polymer compound of the present invention has a side chain containing one arginine or a side chain containing a basic peptide having one or more arginines and a chain length of 2 to 6. Arginine contained in the side chain has guanidino, and the macromolecular compound contains 0.5-20 mmol/g guanidino. It is considered that the macromolecular compound induces macropinocytosis (macropinocytosis) of cells when it approaches the cell membrane due to having a guanidine group within the above range. Cells are difficult to introduce macromolecular compounds that are macromolecules, because they introduce macromolecular compounds that contain arginine and the like through macropinocytosis. On the other hand, compounds such as drugs coexisting in the polymer compound have a smaller molecular weight than the polymer compound, and therefore are introduced into cells. That is, it is presumed that the polymer compound of the present invention contains 0.5 to 20mmol/g of guanidino group, and therefore, it induces megalocytosis of cells, and thus, the coexisting compounds such as drugs are introduced into the cells. On the other hand, it is presumed that macropinocytosis can be induced and the effects of the present invention can be exerted if the main chain polymer of the polymer compound has a side chain containing one arginine or a side chain containing one or more basic peptides having a chain length of 2 to 6 and containing one or more arginines bonded thereto. Therefore, in the polymer compound of the present invention, the main chain polymer is not limited to a specific main chain polymer.

Examples

The present invention will be specifically described below with reference to examples, but these examples do not limit the scope of the present invention. In the examples, "part(s)" or "%" are based on mass unless otherwise specified.

< example 1>

In this example, a polymer compound having one arginine in the side chain was prepared using an acrylic acid/N-vinylacetamide copolymer as the main chain polymer.

(Synthesis of succinimide body of acrylic acid/N-vinylacetamide copolymer)

Referring to example 14 of Japanese Kokai publication Hei-08-081428, a copolymer (NVA-AANa polymer) was synthesized in accordance with a conventional method, starting with 30.0g of sodium acrylate and 70.0g of N-vinylacetamide.

Subsequently, the column tube was packed with a cation exchange resin (IR120B, manufactured by ORGANO CORPORATION), and 130.0g of a 5.0 wt% aqueous NVA-AANa polymer solution was passed through the column tube at 2.6mL/min to obtain an aqueous NVA-AANa polymer solution. The resulting aqueous NVA-AANa polymer solution was freeze-dried to obtain 5.7g of NVA-AANa polymer.

A300 mL five-necked flask was charged with NVA-AANa polymer (5.0g) and DMF (142.0g), and cooled to 10 ℃ or below using an ice-water bath. To this solution was added dropwise a DMF solution of 58.2g (0.2g/mL) of N-hydroxysuccinimide at 2.0 mL/min. A DMF solution of 66.2g (0.4g/mL) of N, N' -dicyclohexylcarbodiimide was further added dropwise at 1.0 mL/min. After stirring for 1 hour in an ice-water bath, the temperature was raised to room temperature and stirred for 24 hours. The reaction solution was filtered with suction and the filtrate was recovered, and reprecipitation was carried out using 2L of acetonitrile. The precipitate was then washed with 2L of acetone and the solid recovered by suction filtration. The resulting solid was dried under reduced pressure to obtain 5.4g of a succinimide-esterified NVA-AA polymer (NVA-AA polymer OSu body).

(introduction of basic peptide)

10.0mg of the NVA-AA polymer OSu was dissolved in 1.0mL of DMF. To this solution, 0.2mL of mono-L-arginine (NH) was mixed₂R1/L Merck) (77.5mg/mL) and 0.02mL of triethylamine (manufactured by TCI), and stirred at 50 ℃ for 24 hours. Then, the mixture was diluted with 1.0mL of ion-exchanged water, added to a cellulose dialysis tube (a seamless cellulose tube, manufactured by SPECTRUM Inc.), the both ends of the tube were pulled up, and then dialyzed with ion-exchanged water for 5 days. After purification, the liquid in the tube was lyophilized to obtain 11.5mg of a polymer compound (hereinafter, may be referred to as NVA-AA-R1/L) into which mono-L-arginine was introduced. The molecular weight was 375000(PEG/PEO conversion) by GPC.

(measurement of guanidyl group)

The obtained polymer compound was measured¹H-NMR was conducted to determine the content of the group derived from arginine, and from the result, the guanidine group of each polymer was calculatedDensity.

¹H-NMR(400MHz，D₂O)：δ＝4.16-3.75(br，1H)，3.50-3.31(br，0.67H)

Specifically, the procedure was as follows. First, by measuring NVA-AA polymer before introduction of arginine¹H-NMR was carried out to calculate the ratio of x/(y + z) of the "repeating unit" of the following structural formula (4).

Next, x/z is calculated from the integrated value of one hydrogen atom (× 1) and two hydrogen atoms (× 2) in the following formula (4). From these results, the ratio of x/y/z (14/1.32/4.68 in example 1) was obtained.

The "repeating unit" herein refers to a repeating structure based on the structural ratio of the monomer units constituting the main chain of the polymer compound (in example 1, a moiety derived from N-vinylacetamide, a moiety derived from acrylic acid, and a moiety derived from acrylic acid bonded to a peptide chain). When the main chain is a random copolymer, a structure in which a block-like arrangement based on the structure ratio is repeated is regarded as a "repeating unit" for convenience.

The number of moles of guanidine groups contained in one repeating unit (composed of 14/1.32/4.68 in x/y/z in example 1) can be calculated by multiplying z by the number of repetitions of arginine contained in the basic peptide, thereby calculating the number of moles of guanidine groups contained in the unit structural formula (in this example, the number of repetitions of arginine is 1 because arginine is 1).

The density of guanidine groups of the polymer was calculated by dividing the "number of moles of guanidine groups" obtained by the molecular weight (weight for convenience) of the unit structural formula having the above-mentioned x/y/z. The results are shown in Table 1.

[ chemical formula 4]

< example 2>

In this example, a polymer compound having 2 arginines in the side chain was prepared using an acrylic acid/N-vinylacetamide copolymer as a main chain polymer.

Except that a basic peptide (NH) consisting of 2L-arginines is used₂-R2/L) instead of mono-L-arginine, the procedure of example 1 was repeated to obtain 16.5mg of a polymer compound having 2 arginines introduced thereinto (hereinafter, may be referred to as NVA-AA-R2/L). The molecular weight was 482000(PEG/PEO conversion) by GPC. The density of guanidine groups was calculated in the same manner as in example 1. The results are shown in Table 1.

< example 3>

In this example, a polymer compound having 4 arginines in the side chain was prepared using an acrylic acid/N-vinylacetamide copolymer as a main chain polymer.

Except that a basic peptide (NH) consisting of 4L-arginines is used₂-R4/L) instead of mono-L-arginine, the procedure of example 1 was repeated to obtain 20.3mg of a polymer compound having 4 arginines introduced thereinto (hereinafter, may be referred to as NVA-AA-R4/L). The molecular weight was 531000(PEG/PEO conversion) by GPC. The density of guanidine groups was calculated in the same manner as in example 1. The results are shown in Table 1.

< comparative example 1>

In this comparative example, a polymer compound having 8 arginines in the side chain was prepared using an acrylic acid/N-vinylacetamide copolymer as the main chain polymer.

Except that a basic peptide (NH) consisting of 8L-arginines is used₂-R8/L) instead of mono-L-arginine, the procedure of example 1 was repeated to obtain 17.8mg of a polymer compound having 8L-arginines introduced therein (hereinafter, may be referred to as NVA-AA-R8/L). The molecular weight was 671000(PEG/PEO conversion) by GPC. The density of guanidine groups was calculated in the same manner as in example 1. The results are shown in Table 1.

< comparative example 2>

In this comparative example, a polymer compound having 8 arginines in the side chain was prepared using an acrylic acid/N-vinylacetamide copolymer as the main chain polymer.

The procedure of example 1 was repeated except that a basic peptide consisting of 8D-arginines was used in place of the mono-L-arginine to obtain 17.8mg of a polymer compound having 8D-arginines introduced therein (hereinafter, may be referred to as NVA-AA-R8/D). The molecular weight was 611000(PEG/PEO conversion) by GPC. The density of guanidine groups was calculated in the same manner as in example 1. The results are shown in Table 1.

< evaluation of introduction into cells >

The introduction of FITC-OVA into cells was measured using the polymer compounds obtained in examples 1 to 3 and comparative examples 1 to 2.

mu.L of Ham's F12 medium suspension (2X 10) of Chinese hamster ovary-derived cells (CHO cells) was seeded into each well of a 24-well plate⁵Individual cells/mL), in a carbon dioxide incubator (37 ℃, 5% CO)₂) Pre-culture for 24 hours. After removing the supernatant and washing twice with 500. mu.L of phosphate buffered saline, 250. mu.L of Ham's F12 medium solution (final concentration 5. mu.g/mL) of fluorescein-labeled-ovalbumin (FITC-OVA; manufactured by Thermo Fisher Scientific, Inc.) was added. Then, 250. mu.L of a solution (final concentration: 1. mu.g/mL) obtained by dissolving the polymer compounds obtained in examples 1 to 3 and comparative examples 1 to 2 in Ham's F12 medium solution was added thereto, and the mixture was cultured in a carbon dioxide incubator for 2 hours. After removing the supernatant medium solution and washing twice with 500. mu.L of phosphate buffered saline, 100. mu.L of trypsin EDTA solution (manufactured by Life Technologies) was added, and the cultured CHO cells were detached from the plate and dispersed. Subsequently, 400. mu.L of Trypan Blue (Trypan Blue) was added to suspend the cells, and the cells were collected in a microtube. The recovered cell suspension was passed through a cell filter, and MFI (mean fluorescence intensity) was measured by a flow cytometer. As a control, an example of adding only an acrylic acid/N-vinylacetamide copolymer (backbone polymer), an example of adding only a basic peptide consisting of 4 arginines (R4/L), an example of adding only FITC-OVA (FITC-OVA), and an example of adding only cells (cells) were carried out. The results are shown in Table 1.

Extracellular FITC-OVA was quenched by trypan blue and did not fluoresce, and only FITC-OVA introduced into cells fluoresced. MFI represents the average value of fluorescence intensity per cell, and therefore, the larger the MFI value, the more FITC-OVA as a water-soluble polymer compound has been introduced into cells.

The "introduction rate" of FITC-OVA was calculated by flow cytometry analysis. The "introduction rate" is a value obtained by measuring the ratio of the number of cells larger than a reference value when FITC-OVA is introduced into cells, based on the maximum value of autofluorescence when only cells are measured.

The results are shown in table 1.

< evaluation of cytotoxicity >)

Cytotoxicity was determined using the cytotoxin LDH Assay Kit-WST (Homond chemistry).

100 μ L of Ham's F12 medium suspension of CHO cells (2X 10) were seeded into each well of a 96-well plate⁵Individual cells/mL), in a carbon dioxide incubator (37 ℃, 5% CO)₂) Pre-culture for 24 hours. To the cells were added 220. mu.L of a solution (final concentration: 5. mu.g/mL) obtained by dissolving the polymer compounds obtained in examples 1 to 3 and comparative examples 1 to 2 in Ham's F12 medium solution, 220. mu.L of Ham's F12 medium was added to the low control well, 200. mu.L of the medium was added to the high control well, 220. mu.L of the medium was added to the background blank well (cell-free well), and the cells were cultured in a carbon dioxide incubator for 1.5 hours. Then 20. mu.L of Lysis Buffer was added to the high control wells and further incubated for 30 minutes in a carbon dioxide incubator. 100. mu.L of the supernatant was removed from each well and transferred to a 96-well microplate for assay. To all wells, 100. mu.L of Working Solution was added, and a color reaction was performed at room temperature for 30 minutes in the dark, and then to all wells, 50. mu.L of Stop Solution was added. The absorbance at 490nm was measured using a plate reader, and the cytotoxicity (%) was calculated. The results are shown in table 1.

[ Table 1]

The crude protein is the following components: FITC-OVA (1 mu g/mL)

The concentrations of the polymer compounds, the main chain polymer and R4/L of examples 1 to 3 and comparative examples 1 to 2 added during measurement are as follows: 5 μ g/mL

When the polymer compounds obtained in examples 1 to 3 were used, they showed a high MFI of 30.13 to 166.7 as compared with the MFI of 4.04 to 4.36 of the control. In addition, with respect to the rate of introduction into cells, the polymer compounds of examples 2 and 3 showed almost the same introduction rate as that of comparative example 1, and the polymer compound of example 1 was also introduced into 76% of the cells. On the other hand, regarding cytotoxicity, the polymer compounds of examples 1 to 3 exhibited low cytotoxicity of 1.5% to 6.9% as compared with 8.7% and 8.9% of comparative examples 1-1 and 1-2.

< example 4>

In this example, a polymer compound having 2 glycines and 2 arginines in the side chains was prepared using hyaluronic acid (molecular weight 30,000) as a main chain polymer.

20.0mg of hyaluronic acid (manufactured by TCI, average molecular weight: 30,000) was dissolved in 0.8mL of dimethyl sulfoxide (DMSO) at 60 ℃ with stirring. To this solution, 18mg of N-hydroxysuccinimide dissolved in 0.15mL of DMSO was added, and 34.0mg of Dicyclohexylcarbodiimide (DCC) dissolved in 0.15mL of DMSO was further added, and the mixture was stirred at room temperature for 24 hours. The precipitated solid was filtered off by filtration to give a DMSO solution of succinimide-esterified hyaluronic acid. To the DMSO solution of the succinimide-esterified hyaluronic acid was mixed 0.40mL (116mg/mL) of a basic peptide (NH) composed of 2 glycines and 2L-arginines₂G2R2/L, SIGMA) and 0.04mL triethylamine (manufactured by TCI), and stirred at room temperature for 24 hours. After the reaction, the reaction solution was diluted with 1mL of ion-exchanged water, added to a cellulose dialysis tube (a seamless cellulose tube, manufactured by SPECTRUM Inc.), both ends of the tube were pulled up, and then dialyzed with ion-exchanged water for 5 days. The liquid in the tube was then lyophilized to obtain 14.0mg of a polymer compound (hereinafter, sometimes referred to as HA (30k) -G2R2/L) into which 2 arginines were introduced.

(measurement of guanidyl group)

The obtained polymer compound (HA-G2R2/L) was measured¹H-NMR was carried out to determine the content of the arginine-derived group, and from the result, guanidine per polymer compound was calculatedDensity of the radicals.

¹H-NMR(400MHz，D₂O)：δ＝3.45-3.34(br，1.64H)，2.26-2.12(br，3H)

Specifically, the procedure was as follows.

First, the 1/m ratio is calculated from the integrated values of 3 hydrogen atoms (× 3) and 2 hydrogen atoms (× 4) of the following formula (5). (0.41/0.59 in example 4).

The number of moles of guanidine groups contained in the unit structural formula can be calculated by multiplying 1 by the number of moles of arginine contained in the basic peptide for one repeating unit (in example 4, 1/m is 0.41/0.59) (the number of arginine repeats is 2 in example 4).

The density of guanidine groups of the polymer compound was calculated by dividing the obtained "number of moles of guanidine groups" by the molecular weight (weight for convenience) of the unit structural formula having the following 1/m ratio. The results are shown in Table 2.

[ chemical formula 5]

< example 5>

In this example, a polymer compound having 2 glycines and 2 arginines in the side chains was prepared using hyaluronic acid having a molecular weight of 22 ten thousand as a main chain polymer.

The procedure of example 4 was repeated except that hyaluronic acid having a molecular weight of 22 ten thousand was used instead of hyaluronic acid having a molecular weight of 3 ten thousand, to obtain 21.0mg of a polymer compound (hereinafter, may be referred to as HA (220k) -G2R2) into which 2 glycines and 2L-arginines were introduced.

In this example, two HA (220k) -G2R2/L with different guanidino concentrations were obtained. Table 2 shows examples 5-1 and 5-2. The density of guanidine groups was calculated in the same manner as in example 4. The results are shown in table 2.

< evaluation of introduction into cells >

The introduction of FITC-BSA into cells was measured using the polymer compounds obtained in examples 4 to 5. The procedure for evaluating the intracellular introduction of the polymer compound obtained in examples 1 to 3 and comparative examples 1 to 2 was repeated except that fluorescein-labeled bovine serum albumin (FITC-BSA, manufactured by Thermo Fisher Scientific, inc.) was used instead of FITC-OVA, and the concentrations of the polymer compound, the backbone polymer, G2R2, and FITC-BSA added in examples 4 to 5 were changed. The results are shown in Table 2.

[ Table 2]

The crude protein is the following components: FITC-BSA (10. mu.g/mL)

The concentrations of the polymer compound, the main chain polymer and G2R2 in examples 4 to 5 in the measurement are as follows: 5 μ g/mL

When the polymer compounds obtained in examples 4 to 5 were used, they showed a high MFI of 42.71 to 1761.48, compared with the MFI of 4.26 to 5.05 of the control.

< example 6>

In this example, a polymer compound having 1 arginine in the side chain was prepared using γ -polyglutamic acid (hereinafter abbreviated as γ -PGA) as a main chain polymer.

(Synthesis of succinimide Compound of γ -PGA)

10mg of gamma-PGA (produced by Wako Pure Chemical Industries, Ltd., average molecular weight 200,000 to 500,000) and 1.0mL of DMSO were added, and the mixture was dissolved at 70 ℃ with stirring and then cooled to room temperature. To this solution, 248.8mg (0.12g/mL) of a DMSO solution of N, N' -dicyclohexylcarbodiimide and 236.3mg (0.067g/mL) of a DMSO solution of N-hydroxysuccinimide were mixed, and the mixture was stirred at room temperature for 24 hours. Subsequently, the reaction solution was collected by suction filtration to obtain a DMSO solution of succinimidized γ -PGA (γ -PGA-OSu).

(introduction of basic peptide)

Mixing 4 with DMSO solution of γ -PGA-OSu body28.9mg of mono-L-arginine (NH)₂R1/L, manufactured by Merck) in DMSO (72.3mg/mL) and 0.02mL of triethylamine (manufactured by TCI), and stirred at room temperature for 24 hours. Then, the mixture was diluted with 2.0mL of ion-exchanged water, added to a cellulose dialysis tube (a seamless cellulose tube, manufactured by SPECTRUM Inc.), the both ends of the tube were pulled up, and then dialyzed for 5 days using ion-exchanged water. After purification, the liquid in the tube was lyophilized to obtain 8.8mg of a polymer compound into which di-L-arginine was introduced (hereinafter, may be referred to as γ -PGA-R2/L). The molecular weight was 7,180(PEG/PEO conversion) by GPC.

(measurement of guanidyl group)

The obtained polymer compound (. gamma. -PGA-R1/L) was measured¹H-NMR was carried out to determine the content of the arginine-derived group, and from the result, the density of the guanidine group was calculated for each polymer compound.

¹H-NMR(400MHz，D₂O)：δ＝3.20-3.05(br，0.67H)，2.49-2.19(br，1H)

Specifically, the procedure was as follows.

First, the p/q ratio was calculated from the integrated values of 2 hydrogen atoms (. about.5) and 2 hydrogen atoms (. about.6) of the following formula (6) (0.33/0.67 in example 6).

The number of moles of guanidine groups contained in the unit structural formula can be calculated by multiplying the number of repetitions of arginine contained in the basic peptide by q for one repeating unit (in example 6, p/q is 0.33/0.67) (in example 6, the number of repetitions of arginine is 1 because arginine is 1).

The density of guanidine groups of the polymer compound was calculated by dividing the "number of moles of guanidine groups" obtained by the molecular weight (weight for convenience) of the unit structural formula having the following p/q ratio. The results are shown in Table 3.

[ chemical formula 6]

< example 7>

In this example, a polymer compound having 2 arginines in the side chain was prepared using γ -PGA as a main chain polymer.

Except that a basic peptide (NH) consisting of 2L-arginines is used₂-R2/L) instead of mono-L-arginine, the procedure of example 6 was repeated to obtain 20.2mg of a polymer compound having 2 arginines introduced thereinto (hereinafter, may be referred to as. gamma. -PGA-R2/L). The molecular weight by GPC was 13,900(PEG/PEO conversion). The density of guanidine groups was calculated in the same manner as in example 6. The results are shown in Table 3.

< example 8>

In this example, a polymer compound having 4 arginines in the side chain was prepared using γ -PGA as a main chain polymer.

Except that a basic peptide (NH) consisting of 4L-arginines is used₂-R4/L) instead of mono-L-arginine, the procedure of example 6 was repeated to obtain 21.1mg of a polymer compound into which 4 arginines were introduced (hereinafter, may be referred to as. gamma. -PGA-R4/L). The molecular weight was 7,630(PEG/PEO conversion) by GPC. The density of guanidine groups was calculated in the same manner as in example 6. The results are shown in Table 3.

< example 9>

In this example, γ -PGA was used as a main chain polymer to prepare a polymer compound having 1 glycine and 2 arginines in side chains.

Except that a basic peptide (NH) consisting of 1 glycine and 2L-arginines was used₂-G1R2/L) instead of mono-L-arginine, the procedure of example 6 was repeated to obtain 29.3mg of a polymer compound into which 1 glycine and 2 arginines were introduced (hereinafter, may be referred to as γ -PGA-G1R 2/L). The molecular weight measured by GPC was 14,000(PEG/PEO conversion). The density of guanidine groups was calculated in the same manner as in example 6. The results are shown in Table 3.

< evaluation of introduction into cells >

Using the polymer compounds obtained in examples 6 to 10, the introduction of FITC-OVA into cells was measured.

mu.L of Ham's F12 medium suspension (2X 10) from Chinese hamster ovary cells (CHO cells) was seeded into each well of a 24-well plate⁵Individual cells/mL), in a carbon dioxide incubator (37 ℃, 5% CO)₂) Pre-culture for 24 hours. After removing the supernatant and washing twice with 500. mu.L of phosphate buffered saline, 250. mu.L of Ham's F12 medium solution (final concentration 1. mu.g/mL) of fluorescein-labeled-ovalbumin (FITC-OVA; manufactured by Thermo Fisher Scientific, Inc.) was added. Then, 250. mu.L of a solution (final concentration: 5. mu.g/mL) obtained by dissolving the polymer compound obtained in examples 6 to 10 in Ham's F12 medium solution was added thereto, and the mixture was cultured in a carbon dioxide incubator for 2 hours. After removing the medium solution of the supernatant and washing twice with 500. mu.L of phosphate buffered saline, 100. mu.L of trypsin EDTA solution (manufactured by Life Technologies) was added, and the cultured CHO cells were detached from the plate and dispersed. Subsequently, 400. mu.L of trypan blue was added to suspend the cells, and the cells were collected in a microtube. The recovered cell suspension was passed through a cell filter, and MFI (mean fluorescence intensity) was measured by a flow cytometer. As a control, the case of adding only γ -PGA (backbone polymer), the case of adding only basic peptide consisting of 4 arginines (R4/L), the case of adding only FITC-OVA (FITC-OVA), and the case of adding only cells (cells) were carried out. The results are shown in Table 3.

Extracellular FITC-OVA was quenched by trypan blue and did not fluoresce, and only FITC-OVA introduced into cells fluoresced. MFI represents the average value of fluorescence intensity per cell, and therefore, the larger the MFI value, the more FITC-OVA as a water-soluble polymer compound has been introduced into cells.

The "introduction rate" of FITC-OVA was calculated by flow cytometry analysis. The "introduction rate" is a value obtained by measuring the ratio of the number of cells larger than a reference value when FITC-OVA is introduced into cells, based on the maximum value of autofluorescence when only cells are contained.

The results are shown in table 3.

< evaluation of cytotoxicity >)

Cytotoxicity was determined using the cytotoxin LDH Assay Kit-WST (Homond chemistry).

100 μ L of Ham's F12 medium suspension of CHO cells (2X 10) were seeded into each well of a 96-well plate⁵Individual cells/mL), in a carbon dioxide incubator (37 ℃, 5% CO)₂) Pre-culture for 24 hours. 220. mu.L of a solution (final concentration: 5. mu.g/mL) obtained by dissolving the polymer compound obtained in example 6 to 10 in Ham's F12 medium solution was added, 220. mu.L of Ham's F12 medium was added to the low control well, 200. mu.L of Ham's F12 medium was added to the high control well, 220. mu.L of Ham' was added to the background blank well (cell-free well), and the mixture was cultured in a carbon dioxide incubator for 1.5 hours. Then 20. mu.L of lysine Buffer was added to the high control wells and further incubated for 30 minutes in a carbon dioxide incubator. 100. mu.L of the supernatant was removed from each well and transferred to a 96-well microplate for assay. To all wells 100. mu.L of Working Solution was added and a color reaction was performed at room temperature for 30 minutes in the shade, and then to all wells 50. mu.L of Stop Solution was added. The absorbance at 490nm was measured using a plate reader, and the cytotoxicity (%) was calculated. The results are shown in table 3.

[ Table 3]

The crude protein is the following components: FITC-OVA (1 mu g/mL)

On the other hand, since γ -PGA is insoluble in water, it is impossible to evaluate its introduction into cells and cytotoxicity

The concentrations of the polymer compound, the main chain polymer and R4/L in examples 6 to 9 are added during the measurement: 5 μ g/mL

The polymer compounds obtained in examples 6 to 9 showed high MFI of 13 to 36, compared with the MFI of the control of 3.2 to 4.4.

Industrial applicability

The polymer compound of the present invention can be used for introducing a drug with low membrane permeability into a cell.