pH-sensitive block copolymer forming polyionic complex micelles and drug or protein carrier using the same

1. A pH-sensitive block copolymer forming polyionic complex micelles, which is prepared by copolymerization of: (a) a polyethylene glycol compound; (b) a poly(amino acid) compound; and (c) a heterocyclic alkyl amine compound having the ability to induce the formation of ionic complexes, wherein the heterocyclic alkyl amine compound is selected from the group consisting of 1-(3-aminopropyl)imidazole, 1-(2-aminoethyl)pyrrolidine, 2-(2-aminoethyl)-1-methylpyrrolidine, N-(3-aminopropyl)-2-pipecoline, N-(N-methyl-N-benzene)-1-propylamine, N-(3-aminopropyl)-2-pyrrolidinone, 2-(2-pyridyl)ethylamine, 4-(2-aminoethyl)morpholine, 3-morpholinopropylamine, histidine, and mixtures thereof.

2. The pH-sensitive block copolymer according to claim 1 , wherein the polyethylene glycol compound has an acrylate or methacrylate group as a monofunctional group at one end thereof.

3. The pH-sensitive block copolymer according to claim 1 , wherein the polyethylene glycol compound has a number average molecular weight (M n ) of 500 to 5,000 g/mol.

4. The pH-sensitive block copolymer according to claim 1 , wherein the poly(amino acid) compound is a poly(β-amino ester) (PAE), a poly(β-amido amine) (PAA) or a copolymer thereof (PAEA).

5. The pH-sensitive block copolymer according to claim 1 , wherein the poly(amino acid) compound is prepared by polymerization of a bisacrylate or bisacrylamide compound with a primary or secondary amine compound.

6. The pH-sensitive block copolymer according to claim 5 , wherein the bisacrylate compound is selected from the group consisting of ethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,3-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,5-pentanediol diacrylate, 2,5-pentanediol diacrylate, 1,6-hexanediol ethoxylate diacrylate, 1,6-hexanediol propoxylate diacrylate, 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpropionate diacrylate, 1,7-heptanediol diacrylate, 1,8-octanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, and mixtures thereof; and the bisacrylamide compound is N,N′-methylene bisacrylamide (MDA) or N,N′-ethylene bisacrylamide.

7. The pH-sensitive block copolymer according to claim 5 , wherein the primary amine compound is selected from the group consisting of 1-methylamine, 1-ethylamine, 1-propylamine, 1-butylamine, 1-pentylamine, 1-hexanamine, 1-heptanamine, 1-octanamine, 1-nonanamine, 1-decanamine, 1-isopropylamine, triethyleneamine, 3-methoxypropylamine, 3-ethoxypropylamine, 3-isopropoxy-1-propanamine, 3-propyl-1-propanamine, 3-butoxy-1-propanamine, 1,4-dioxa-1-ethoxyamine, 4,4-dimethoxybutylamine, 4,4-diethoxy-1-butanamine, 2-methoxyethanamine, 3-ethoxyethanamine, 3-isopropoxy-1-ethoxyethanamine, 4,4-dimethoxyethylamine, 4,4-diethoxy-1-ethylamine, tetrahydro-2-furanylmethylamine, 2-phenoxyethanamine, 2-(3,4-dimethoxyphenyl)ethanamine, 2-(2,5-dimethoxyphenyl)ethylamine, 1,2,2,-trimethyl-1-propanamine, 2-methyl-1-butanamine, 3-methyl-1-butanamine, 1,3-dimethyl-1-butanamine, 4-methyl-1-pentanamine, 3,3-dimethyl-1-butanamine, 1,4-dimethyl-1-pentanamine, 1-methyl-1-hexanamine, 1-methyl-1-heptanamine, 2-ethyl-1-hexanamine, 2-aminoethanol, 3-amino-1-propanol, (2R)-1-amino-2-propanol, (2S)-1-amino-2-propanol, 2-amino-1-propanol, (2S)-1-amino-2-propanol, 2-amino-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-methyl-1-propanol, 4-amino-1-butanol, 2-amino-1-propanol, 2-ethylamino-1-butanol, 2-(2-aminoethoxy)ethanol, 5-amino-1-pentanol, 3-amino-2,2-dimethyl-1-propanol, 2-amino-2-ethyl-1,3-propanediol, 2-amino-3-methyl-1-butanol, 6-amino-1-hexanol, (1-aminocyclopentyl)methanol, 4-aminocyclohexanol, 2-aminocyclohexanol, 2-methyl-1-propanamine, cyclobutanamine, cyclopropylmethylamine, cyclopentanamine, cyclohexanamine, cyclohexanmethylamine, adamantane-methylamine, Si-methyl-diethoxy-propylamine, Si-trithoxy-propylamine, 1,4-diazepane, N,N′-diethyl-1,2-ethanediamine, N,N′-diisopropyl-1,2-ethanediamine, N,N′-dimethyl-1,2-propanediamine, N,N′-dimethyl-1,3-propanediamine, N,N′-diethyl-1,3-propanediamine, N,N′-diethyl-1,4-pentanediamine, N,N′-bis(2-hydroxyethyl)ethylenediamine, N,N′-bis(2-hydroxyethyl)propylenediamine, and mixtures thereof; and the secondary amine compound is selected from the group consisting of 4,4′-trimethylenepiperidine, N,N′-dimethylethylenediamine, piperazine, 2-methylpiperazine, 3-methyl-4-(3-methylphenyl)piperazine, 3-methylpiperazine, 4-(phenylmethyl)piperazine, 4-(1-phenylethyl)piperazine, 4-(1,1′-dimethoxycarbonyl)piperazine, 4-(2-(bis(2-propenyl)amino)ethyl)piperazine, 1-(2-aminoethyl)piperazine, 4-(aminomethyl)piperazine, N,N′-dimethyl-1,2-ethanediamine, N,N′-diethyl-1,2-ethanediamine, N,N′-diisopropyl-1,2-ethanediamine, N,N′-dimethyl-1,2-propyldiamine, N,N′-diethyl-1,2-propyldiamine, N,N′-diisopropyl-1,2-propyldiamine, N,N′-dimethyl-1,2-hexanediamine, N,N′-dimethyl-N-[3-(methylamino)propyl]-1,3-propanediamine, N-[2-(methylamino)ethoxyethyl]-N,N′-dimethylamine, N-[2-(methylamino)dioxyethyl]-N,N′-dimethylamine, 1,4-diazepane, and mixtures thereof.

8. The pH-sensitive block copolymer according to claim 1 , wherein the pH-sensitive block copolymer has a molecular weight of 1,000 to 20,000 g/mol.

9. A drug or protein carrier comprising the pH-sensitive block copolymer according to any one of claims 1 to 7 and 8 , the copolymer comprising: a hydrophilic block derived from the polyethylene glycol compound; a hydrophobic block derived from the poly(amino acid) compound; and tertiary amine groups ionizable at pH 6.0˜7.0 between the two blocks, wherein the pH-sensitive block copolymer forms micelles in the pH range of 7.0-7.4 by reversible self-assembly, the heterocyclic alkyl amine compound induces the formation of polyionic complexes with the micelles, and the polyionic complexes stably contain a drug or protein during circulation along blood vessels of a human body and release the drug or protein at a disease site.

10. The drug or protein carrier of claim 9 , wherein the drug or protein is an anticancer agent selected from the group consisting of human serum albumin (HSA), paclitaxel, doxorubicin, retinoic acids, cis-platin, camptothecin, fluorouracil (5-FU), docetaxel, tamoxifen, anasterozole, carboplatin, topotecan, belotecan, irinotecan, gleevec and vincristine, an anti-inflammatory agent selected from the group consisting of aspirin, salicylates, ibuprofen, naproxen, fenoprofen, indomethacin, phenyltazone, methotrexate, cyclophosphamide, mechlorethamine, dexamethasone, prednisolone, celecoxib, valdecoxib, nimesulide, cortisone and corticosteroid, or a mixture thereof; and is released when the micelle particles collapse locally at pH<7.0 at a cancer or inflammatory disease site.

11. The drug or protein carrier of claim 10 , wherein a cancer disease at the cancer disease site is breast cancer, lung cancer, uterine cancer, cervical cancer, prostate cancer, pharyngeal cancer, pancreatic cancer, brain tumor, liver cancer, skin cancer, esophageal cancer, testicular cancer, renal cancer, colorectal cancer, thyroid cancer, tongue cancer or rectal cancer.

12. The drug or protein carrier of claim 10 , wherein an inflammatory disease at the inflammatory disease site is rheumatoid arthritis, osteoarthritis or arteriosclerosis.