Amphiphilic polymer

Abstract

The present application relates to an amphiphilic polymer and a method for producing the same. The present application also relates to micelles comprising the amphiphilic polymer and a method for producing the same. The amphiphilic polymer of the present application can have excellent dispersion properties while effectively encapsulating the drug.

Claims

1. An amphiphilic polymer comprising: a first block (A) comprising a polymer having a solubility parameter of 10 (cal/cm.sup.3).sup.1/2 or more; and a second block (B) phase-separated from said first block (A) and comprising a polymerized unit (B1) of a polymerizable monomer satisfying Formula 1 and a polymerized unit (B2) of an acrylic monomer or vinyl monomer having a solubility parameter of a single polymer of less than 10 (cal/cm.sup.3).sup.1/2: ##STR00007## wherein, R is a functional group capable of forming a hydrogen bond, or an alicyclic hydrocarbon group or aromatic substituent group comprising a functional group capable of forming a hydrogen bond, where said functional group is at least one selected from the group consisting of a hydroxyl group, an amine group, a nitro group, an imide group, an alkoxysilane group and a cyano group, and X.sub.1 and X.sub.2 are each independently carbon or nitrogen.

2. The amphiphilic polymer according to claim 1, wherein said first block (A) is any one selected from the group consisting of polyethylene glycol, a polyethylene glycol-propylene glycol copolymer, polyvinyl pyrrolidone and polyethyleneimine.

3. The amphiphilic polymer according to claim 1, wherein said acrylic monomer is a compound represented by Formula 2 or Formula 3: ##STR00008## wherein, Q is hydrogen or an alkyl group, and B in Formula 2 is a linear or branched alkyl group, an alicyclic hydrocarbon group, an aromatic substituent group or a carboxyl group, having at least 1 carbon atom and R.sub.1 and R.sub.2 in Formula 3 are each independently hydrogen, a linear or branched alkyl group, an alicyclic hydrocarbon group or an aromatic substituent group, having at least 1 carbon atom.

4. The amphiphilic polymer according to claim 3, wherein, in Formula 2, Q is hydrogen or an alkyl group having 1 to 4 carbon atoms, and B is an alkyl group having at least 1 carbon atom or an alicyclic hydrocarbon group having 6 to 12 carbon atoms.

5. The amphiphilic polymer according to claim 1, wherein said vinyl monomer is represented by Formula 4 or Formula 5: ##STR00009## wherein, X is a nitrogen atom or an oxygen atom, Y is a carbonyl group or a single bond, R.sub.3 and R.sub.5 are each independently hydrogen or an alkyl group, or R.sub.3 and R.sub.5 are linked together to form an alkylene group, and R.sub.4 is an alkenyl group (provided that when X is an oxygen atom, R3 is not present); ##STR00010## wherein, R.sub.6, R.sub.7 and R.sub.8 are each independently hydrogen or an alkyl group, and R.sub.9 is a cyano group or an aromatic substituent group.

6. The amphiphilic polymer according to claim 1, wherein the polymerized unit (B1) of the polymerizable monomer satisfying Formula 1 and the polymerized unit (B2) of the acrylic monomer or vinyl monomer having a solubility parameter of a single polymer of less than 10.0 (cal/cm.sup.3).sup.1/2 in said second block (B) have a weight ratio (B1:B2) in a range of 0.5:99.5 to 50:50.

7. The amphiphilic polymer according to claim 6, wherein the polymerized unit (B1) of the polymerizable monomer satisfying Formula 1 and the polymerized unit (B2) of the acrylic monomer or vinyl monomer having a solubility parameter of a single polymer of less than 10.0 (cal/cm.sup.3).sup.1/2 in said second block (B) have a weight ratio (B1:B2) in a range of 1:99 to 30:70.

8. The amphiphilic polymer according to claim 1, wherein said first block (A) and said second block (B) have a block ratio (A:B) different from each other.

9. The amphiphilic polymer according to claim 1, wherein said first block (A) and said second block (B) have a block ratio (A:B) of 1:9 to 9:1.

10. The amphiphilic polymer according to claim 9, wherein said first block (A) and said second block (B) have a block ratio (A:B) of 3:7 to 7:3.

11. Micelles comprising the amphiphilic polymer of claim 1.

12. The micelles according to claim 11, further comprising a drug encapsulated by said amphiphilic polymer.

13. The micelles according to claim 12, wherein the second block (B) of said amphiphilic polymer is adjacent to the drug.

14. The micelles according to claim 11, having an average particle diameter in a range of 1 nm to 10,000 nm.

15. The micelles according to claim 12, wherein said drug comprises a physiologically active substance.

16. The micelles according to claim 15, wherein said physiologically active substance is poorly soluble.

17. The micelles according to claim 16, wherein said physiologically active substance is any one selected from the group consisting of genistein, daidzein, cucurbitacin, prangenidin or a derivative thereof; and a mixture thereof.

18. A composition for producing particles, comprising the micelles of claim 11.

19. The composition according to claim 18, wherein said micelles further comprise a drug encapsulated by the amphiphilic polymer.

20. The micelles according to claim 16, wherein said physiologically active substance is polyphenols.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a schematic diagram of a micelle comprising an amphiphilic polymer according to the present application.

MODE FOR INVENTION

(2) Hereinafter, the present application will be described in more detail by way of examples, but the examples are merely examples limited to the gist of the present application. Furthermore, it is obvious to those skilled in the art that the present application is not limited to the process conditions set forth in the following examples and they may be optionally selected within the scope of the conditions necessary for achieving the object of the present application.

Example 1: Production of Amphiphilic Polymer (P1)

(3) After dissolving a polyethylene glycol monomethyl ether (mPEG-OH) polymer (molecular weight: 5,000, manufacturer: Aldrich) forming the first block in dichloromethane at a concentration of 30%, 3 equivalents of triethylamine and 2 equivalents of 2-bromoisobutyryl bromide relative to the —OH functional group are added thereto and reacted to prepare an initiator for ATRP. Thereafter, a process of precipitation and collection in a solvent of diethyl ether is repeated twice and dried to obtain a bromine-terminal polyethylene glycol polymer from which impurities have been removed. 100 parts by weight of the obtained bromine-terminal polyethylene glycol polymer was dissolved in 250 parts by weight of an anisole reaction solvent on a flask and 17 parts by weight of styrene (solubility parameter: 8.7 (cal/cm.sup.3).sup.1/2, B1) and 154 parts by weight of methyl methacrylate (solubility parameter: 9.5 (cal/cm.sup.3).sup.1/2, B2) were introduced and the flask was sealed with a rubber stopper. Thereafter, the dissolved oxygen was removed through nitrogen purging and stirring at room temperature for 30 minutes, the flask was immersed in an oil bath set at 60° C., and the reaction was carried out by introducing a cupric bromide complex and a catalyst reducing agent. When the desired molecular weight was prepared, the reaction was terminated to prepare an amphiphilic polymer (P1). The molecular weight and the block ratio (A:B) of the amphiphilic polymer (P1) and the weight ratio (B1:B2) of the polymerized units in the second block (B) are shown in Table 1 below.

Example 2: Production of Amphiphilic Polymer (P2)

(4) After dissolving a polyethylene glycol monomethyl ether (mPEG-OH) polymer (molecular weight: 5,000, manufacturer: Aldrich) forming the first block in dichloromethane at a concentration of 30%, 1.5 equivalents of 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid and 1.5 equivalents of 1,3-dicyclohexyl carbodiimide and 1.5 equivalents of 4-(dimethylamino)pyridine relative to the —OH functional group are added thereto and reacted to prepare an initiator for RAFT. Thereafter, a process of precipitation and collection in a solvent of diethyl ether is repeated twice and dried to obtain an RAFT agent-terminal polyethylene glycol polymer from which impurities have been removed. The obtained RAFT agent-terminal polyethylene glycol monomethyl ether polymer was dissolved in an anisole reaction solvent on a flask and N,N-dimethyl vinylbenzyl amine (B1):methyl methacrylate (solubility parameter: 9.5 (cal/cm.sup.3).sup.1/2, B2) were introduced in a weight ratio of 10:90 and the flask was sealed with a rubber stopper. Thereafter, the dissolved oxygen was removed through nitrogen purging and stirring at room temperature for 30 minutes, the flask was immersed in an oil bath set at 60° C., and the reaction was carried out by introducing AIBN. When the desired molecular weight was prepared, the reaction was terminated to prepare an amphiphilic polymer (P2). The molecular weight and the block ratio (A:B) of the amphiphilic polymer (P2) and the weight ratio (B1:B2) of the polymerized units in the second block (B) are shown in Table 1 below.

Example 3: Production of Amphiphilic Polymer (P3)

(5) 2.5 parts by weight of NaH relative to 5 parts by weight of TEMPO ((2,2,6,6-tetramethyl-piperidin-1-yl)oxyl) is dissolved in DMF (dimethylformaldehyde) at a concentration of 10%, stirred for 1 hour under reflux, and then 100 parts by weight of a bromine-terminal polyethyleneglycol monomethylether (prepared in Example 1) polymer dissolved in DMF (dimethylformaldehyde) at a concentration of 20% is dropped. After stirring for 24 hours under reflux, the excess amount of NaH is removed by dropping methanol, and then a process of precipitation and collection in a solvent of diethyl ether is repeated twice and dried to obtain an alkoxy amine-terminal polyethylene glycol polymer from which impurities have been removed. The above-prepared alkoxy amine-terminal polyethyleneglycol monomethyl ether polymer was dissolved in an anisole reaction solvent on a flask and 4-(3-vinylphenyl)pyridine (B1): methyl methacrylate (solubility parameter: 9.5 (cal/cm.sup.3).sup.1/2, B2) were introduced in a weight ratio of 30:70 and the flask was sealed with a rubber stopper. Thereafter, the dissolved oxygen was removed through nitrogen purging and stirring at room temperature for 30 minutes, the flask was immersed in an oil bath set at 120° C., and the reaction was carried out. When the desired molecular weight was prepared, the reaction was terminated to prepare an amphiphilic polymer (P1). The molecular weight and the block ratio (A:B) of the amphiphilic polymer (P1) and the weight ratio (B1:B2) of the polymerized units in the second block (B) are shown in Table 1 below.

Example 4: Production of Amphiphilic Polymer (P4)

(6) After dissolving a polyethylene glycol monomethyl ether polymer (molecular weight: 5,000, manufacturer: Aldrich) forming the first block in dichloromethane at a concentration of 30%, 1.5 equivalents of 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid and 1.5 equivalents of 1,3-dicyclohexyl carbodiimide and 1.5 equivalents of 4-(dimethylamino)pyridine relative to the —OH functional group are added thereto and reacted to prepare an initiator for RAFT. Thereafter, a process of precipitation and collection in a solvent of diethyl ether is repeated twice and dried to obtain an RAFT agent-terminal polyethylene glycol polymer from which impurities have been removed. The obtained RAFT agent-terminal polyethylene glycol monomethyl ether polymer was dissolved in an anisole reaction solvent on a flask and styrene (B1): methyl methacrylate (solubility parameter: 9.5 (cal/cm.sup.3).sup.1/2, B2) were introduced in a weight ratio of 50:50 and the flask was sealed with a rubber stopper. Thereafter, the dissolved oxygen was removed through nitrogen purging and stirring at room temperature for 30 minutes, the flask was immersed in an oil bath set at 80° C., and the reaction was carried out by introducing AIBN. When the desired molecular weight was prepared, the reaction was terminated to prepare an amphiphilic polymer.

Comparative Example 1: Production of Amphiphilic Polymer (P5)

(7) Polyethylene glycol monomethyl ether polymer (molecular weight: 5000, manufacturer: Aldrich) forming the first block was dried in Sn(Oct).sub.2 and 2-neck round flask at 110° C. under vacuum for 4 hours to remove moisture and then the reactor was cooled to room temperature. Polyethylene glycol monomethyl ether and the same amount of ε-caprolactone were added to the reactor in a nitrogen atmosphere, followed by vacuum drying at 60° C. for 1 hour. The reactor was gradually heated to 130° C. in a nitrogen atmosphere, reacted for 18 hours, and cooled to room temperature to terminate the reaction. To the reactor cooled to room temperature, methylene chloride was added to dissolve the reactant, and then slowly added to the excess amount of cold ethyl ether to precipitate the copolymer. The precipitated block copolymer was filtered and then vacuum-dried at 40° C. for 48 hours to finally obtain a polyethylene glycol (A)-polycaprolactone (B) copolymer (P5).

Comparative Example 2: Production of Amphiphilic Polymer (P6)

(8) A polyethylene glycol (A)-polycaprolactone (B) copolymer (P6) was synthesized in the same manner as in Comparative Example 1 and produced, except that a double amount of ε-caprolactone relative to polyethylene glycol monomethyl ether was added upon synthesizing the copolymer.

Comparative Example 3: Production of Amphiphilic Polymer (P7)

(9) After dissolving a polyethylene glycol monomethyl ether polymer (molecular weight: 5,000, manufacturer: Aldrich) forming the first block in dichloromethane at a concentration of 30%, 3 equivalents of triethylamine and 2 equivalents of 2-bromoisobutyryl bromide relative to the —OH functional group are added thereto and reacted to prepare an initiator for ATRP. Thereafter, a process of precipitation and collection in a solvent of diethyl ether is repeated twice and dried to obtain a bromine-terminal polyethylene glycol polymer from which impurities have been removed. 100 parts by weight of the obtained bromine-terminal polyethylene glycol polymer was dissolved in 250 parts by weight of an anisole reaction solvent on a flask and 150 parts by weight of methyl methacrylate was introduced and the flask was sealed with a rubber stopper. Thereafter, the dissolved oxygen was removed through nitrogen purging and stirring at room temperature for 30 minutes, the flask was immersed in an oil bath set at 60° C., and the reaction was carried out by introducing a cupric bromide complex and a catalyst reducing agent. When the desired molecular weight was prepared, the reaction was terminated to prepare an amphiphilic polymer.

Comparative Example 4: Production of Amphipathic Polymer (P8)

(10) 2.5 parts by weight of NaH relative to 5 parts by weight of TEMPO ((2,2,6,6-tetramethyl-piperidin-1-yeoxyl) is dissolved in DMF (dimethylformaldehyde) at a concentration of 10%, stirred for 1 hour under reflux, and then 100 parts by weight of a bromine-terminal polyethyleneglycol monomethylether (prepared in Example 1) polymer dissolved in DMF (dimethylformaldehyde) at a concentration of 20% is dropped. After stirring for 24 hours under reflux, the excess amount of NaH is removed by dropping methanol, and then a process of precipitation and collection in a solvent of diethyl ether is repeated twice and dried to obtain an alkoxy amine-terminal polyethylene glycol polymer from which impurities have been removed. The above-prepared alkoxy amine-terminal polyethyleneglycol monomethyl ether polymer was dissolved in an anisole reaction solvent on a flask and styren (B1) was introduced and the flask was sealed with a rubber stopper. Thereafter, the dissolved oxygen was removed through nitrogen purging and stirring at room temperature for 30 minutes, the flask was immersed in an oil bath set at 120° C., and the reaction was carried out. When the desired molecular weight was prepared, the reaction was terminated to prepare an amphiphilic polymer.

Experimental Example 1—Evaluation of Block Ratio and Molecular Weight of the Produced Amphiphilic Polymer

(11) The block ratio and the molecular weight of the produced amphiphilic polymers (P1-P8) were evaluated by the following methods and shown in Table 1.

(12) Specifically, the polymer solution was solidified through a purification step of the polymer solution in which the catalyst was completely removed and then the block ratio of the amphiphilic polymer was confirmed through .sup.1H NMR analysis. In the purification of the polymer solution, the polymer solution is solidified by passing it through an alumina column to remove the copper complex catalyst or dropping it to hexane with stirring in the absence of the step to remove the residual monomers. The solidified polymer is dried in a vacuum oven for 24 hours. The amphiphilic polymer purified by the above method is dissolved in a solvent of CDCl.sub.3 and measured with a .sup.1H NMR analysis instrument.

(13) As an analytical result of Examples 1 to 4, no 1H peak derived from CH.sub.2═C(CH.sub.3)— of the methylmethacrylate double bond terminal was confirmed, and no 1H peak derived from CH.sub.2═C— of the vinyl monomer was also confirmed. Accordingly, it can be confirmed that no unreacted monomer is present.

(14) Also, in the case of Examples 1 to 4 and Comparative Examples 1 to 4, since 3H peaks derived from —OCH.sub.3 of the ethylene glycol block terminal were confirmed at around 3.2 ppm, and the ratio and molecular weight of each polymer block were calculated, based on the above. Since peaks of about 450 H (4H X repeating units: 113) derived from —CH.sub.2CH.sub.2O— of ethylene glycol formed into the polymer appeared in the region of 3.6-3.8 ppm, and in the case of Examples 1 to 4 and Comparative Examples 3 and 4, 3H peaks derived from —CH.sub.3 adjacent to the main chain of methyl methacrylate formed into the polymer appeared in the region of 3.5-3.6 ppm and 4H to 8H peaks derived from benzene rings of the side chain formed into the polymer appeared in the region of 7.2 ppm or less, the content of each constituent monomer was calculated as a mass fraction through an area ratio thereof.

(15) In the case of Comparative Examples 1 and 2, since 2H peaks derived from the first —CH.sub.2— on the right of —CO— in —(COCH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.sub.2—O).sub.n—, which is a chain of caprolactone formed into the polymer, appeared in the region of 2.3-2.4 ppm, the molecular weight was confirmed through the 3H peak area derived from —OCH.sub.3 of the ethylene glycol terminal and the 2H peak area derived from the first —CH.sub.2— on the right of —CO— of caprolactone.

(16) TABLE-US-00001 TABLE 1 Weight Ratio of Second Block Molecular Weight Block Ratio Polymerized Units (Mn, A:B) (A:B) (B1:B2) Example 1 11,000 (5000:6000) 4.55:5.45 10:90 Example 2 11,000 (5000:6000) 4.55:5.45 10:90 Example 3 11,000 (5000:6000) 4.55:5.45 30:70 Example 4 11,000 (5000:6000) 4.55:5.45 50:50 Comparative  9,900 (5000:4900) 5.05:4.95 — Example 1 Comparative 14,700 (5000:9700) 3.40:6.60 — Example 2 Comparative 10,500 (5000:5500) 4.76:5.24 — Example 3 Comparative 11,000 (5000:6000) 4.55:5.45 — Example 4

Experimental Example 2—Preparation of Micelle and Measurement of Turbidity

(17) Genistein as a poorly soluble material was encapsulated using the synthesized amphiphilic polymer (P1 to P8). First, a solution of 10 g of the amphiphilic polymer dissolved in 30 mL of ethanol was mixed with a solution of 2 g of genistein dissolved in 20 g of dipropylene glycol (DPG). The solution was slowly added to 100 mL of an aqueous solution of 0.5% polyvinyl alcohol while stirring. After being left while stirring for a certain period of time to evaporate the solvent of ethanol, the solution was prepared to have a genistein content of 2%, by removing the residual ethanol using a rotary evaporator. The prepared solution was diluted with 10 times of purified water and then stored at room temperature (25° C.) for 7 days, and the change over time was confirmed by a turbidity measurement and shown in Table 3. It was measured using Turbiscan from Formulaction Co., Ltd., and the upper liquid of the solution stored for 7 days was sampled to measure transmittance, and the turbidity was shown by the following equation 1.
Turbidity=Log(1/(transmittance(T)))  [Equation 1]

(18) TABLE-US-00002 TABLE 2 Example Comparative Example 1 2 3 4 1 2 3 4 0 day 0.137 0.201 0.215 0.2 0.155 0.125 0.09 0.13 7 day after 0.129 0.227 0.282 0.192 0 0 0.05 0.05

(19) Through the turbidity measurement of the micelle solution, the change over time in the sample was confirmed, and in the case of Comparative Examples, it could be confirmed that the stabilization of the capsules was decreased due to the agglutination of the drug, and thus all the capsules sank after 7 days.

Experimental Example 3—Confirmation of Dissolution Concentration of Drug

(20) The solution prepared to have a genistein content of 2% in Experimental Example 2 above was diluted with 10 times of purified water and filtered with a syringe filter (pore size: 1 μm) to remove the precipitated genistein, and then the content of genistein encapsulated in the amphiphilic polymer micelle particles was measured from liquid chromatography (HPLC). Drug loading capacity and drug loading efficiency of the amphiphilic polymer were calculated by the following equations and the particle size of the micelle particles containing the amphiphilic polymer in which the drug was collected was measured using Zetasizer 3000 from Malvern Ltd.

(21) $\begin{array}{cc}\mathrm{Drug}\mathrm{loading}\mathrm{capacity}=\frac{\mathrm{Drug}\mathrm{impregnation}\mathrm{amount}}{\begin{array}{c}\mathrm{Drug}\mathrm{impregnation}\mathrm{amount}+\\ \mathrm{Bolock}\mathrm{copolymer}\mathrm{content}\end{array}}\times 100\left(\%\right)& \left[\mathrm{Equation}2\right]\\ \mathrm{Drug}\mathrm{loading}\mathrm{efficiency}=\frac{\mathrm{Drug}\mathrm{impregnation}\mathrm{amount}}{\mathrm{Initial}\mathrm{drug}\mathrm{input}}\times 100\left(\%\right)& \left[\mathrm{Equation}3\right]\end{array}$

(22) TABLE-US-00003 TABLE 3 Example Comparative Example 1 2 3 4 1 2 3 4 Particle size 190 250 265 205 100 150 110 160 (diameter, nm) Loading 16.5 18.9 15.8 15 1.2 1.8 2.4 2.2 capacity (%) Loading 82 96 78 80 6 9 13 9 efficiency (%)

EXPLANATION OF REFERENCE NUMERALS

(23) 100: drug 200: amphiphilic polymer 201: first block 202: second block