Monomolecular micelle aqueous solution as well as preparation method and application thereof

Abstract

The invention relates to a monomolecular micelle aqueous solution as well as a preparation method and application thereof, and belongs to the technical field of biomedicine. The monomolecular micelle aqueous solution is formed by assembling an amphiphilic polyether ester multi-block copolymer in an aqueous phase. The preparation method comprises the following steps: dissolving an amphipathic multi-block copolymer in a good solvent, slowly adding deionized water into the amphipathic multi-block copolymer, or slowly dropwise adding the amphipathic multi-block copolymer into a large amount of deionized water, self-assembling to form a monomolecular micelle, and removing the good solvent in water through dialysis to obtain a monomolecular micelle aqueous solution. And the amphiphilic polyether ester multi-block copolymer has good biocompatibility and degradability. The prepared monomolecular micelle has excellent stability and cannot be dissociated along with the dilution of the polymer concentration, and the problem that the current common micelle is dissociated along with the dilution of the polymer concentration is solved. The prepared monomolecular micelle has a good solubilizing effect on water-insoluble drugs, and can be used in the fields of drug extraction, drug delivery, controllable release and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of biological medicine, in particular to a monomolecular micelle aqueous solution and a preparation method and application thereof. BACKGROUND

[0002] In recent years, polymer micelles as carriers for cancer treatment have attracted extensive attention. Polymer micelles are usually formed by the aggregation of block copolymer molecules, have good biocompatibility, and excellent ability to dissolve hydrophobic anticancer drugs. Meanwhile, polymer micelles with a suitable size (10-150 nanometers (nm)) can be enriched at the tumor site by utilizing the enhanced permeability and retention (EPR) effect at the tumor site, thus realizing passive targeting treatment, so polymer micelles are called one of the most potential nano-drug carrier systems. However, the polymer micelles formed by self-assembly of traditional two-block or three-block copolymers will dissociate and release the loaded drugs due to dilution after being injected into the human body, which on the one hand reduces the therapeutic effect, and on the other hand, the drugs released in advance can cause damage to healthy tissues or cells, which restricts the application of polymer micelles in the field of cancer treatment.

[0003] In order to overcome the problem of insufficient stability of micelles, researchers have explored various strategies, among which the introduction of cross-linkable groups into the core or shell of micelles to form covalent bonds can improve the structural stability of micelles. For example, Biswas et al. designed an ABA type triblock copolymer containing a disulfide bond, and the micelles formed thereby still maintain the stability of colloids in the blood dilution environment, and realize the rapid release of drugs under the stimulation of intracellular glutathione, so as to be used for tumor targeted chemotherapy [D. Biswas, Molecular Pharmaceutics 2017, 14 (8), 2518-2528], but the cross-linking process is much more complex than the formation of ordinary micelles, and the current research has only remained in the preclinical research stage.

[0004] Proteins in living organisms can specifically bind to certain drugs, and they will not release drugs with the dilution of concentration. This is because proteins can fold to exist in the form of monomers, which can be considered to form monomolecular micelles. Therefore, monomolecular micelles are expected to solve the problem of insufficient stability of micelles. In addition, the diameter of monomolecular micelles is usually only 10-30 nm, which is much smaller than the micelles formed by the aggregation of multiple molecules, which is conducive to the penetration of drugs into diseased tissues; and monomolecular micelles will not be destroyed due to changes in concentration, temperature and other factors, which makes monomolecular micelles still maintain stability under extremely dilute conditions, so monomolecular micelles have unique advantages in the field of biological medicine.

[0005] At present, the polymer that can form a unimolecular micelle is mainly a dendritic polymer. Fan et al. synthesized an RGD peptide modified dendritic macromolecular amphiphilic copolymer, which can self-assemble into a unimolecular micelle in an aqueous solution, can efficiently load hydrophobic anticancer drug doxorubicin (DOX), and exhibits excellent pH-responsive drug release behavior, thereby realizing targeted therapy [X. Fan, Journal of Materials Chemistry B 2017, 5, 1062-1072]. However, the dendritic polymer has problems such as complex synthesis method, low synthesis efficiency, high cost, and slow in-vivo degradation rate due to its special structure, which causes problems in clinical application and other aspects, and thus has not been practically applied.

[0006] Based on the above analysis, it is necessary to develop a unimolecular micelle with small particle size, capable of loading hydrophobic drugs and stably existing under the dilution condition of the circulatory system. The unimolecular micelle has great significance for the treatment of cancer. SUMMARY

[0007] To solve the above technical problems, the present application provides a unimolecular micelle aqueous solution and a preparation method and application thereof. Since the multi-block copolymer is easier to fold, and the hydrophilic segment can stabilize the insoluble block, the unimolecular micelle is theoretically easier to form than the two-block copolymer. The present method uses an amphiphilic polyether ester multi-block copolymer to prepare a unimolecular micelle through self-assembly in an aqueous solution, and the particle size of the unimolecular micelle is smaller than that of the multi-block copolymer in a good solvent. The polyether ester multi-block copolymer used is composed of an aliphatic polyether block and an aliphatic polyester block, and thus has good biocompatibility and degradability. The prepared unimolecular micelle aqueous solution has a good solubilizing effect on hydrophobic drugs through the microphase formed by the aliphatic polyester, and does not release drugs with the change of concentration. On the other hand, under the catalysis of biological enzymes and the like, the aliphatic polyester block can be degraded to destroy the unimolecular micelle, so that the drug is released. The unimolecular micelle prepared by the present application has a small size, and can realize passive targeted treatment of tumors by utilizing the EPR effect of tumor sites.

[0008] The present application is realized by the following technical solutions:

[0009] The first object of the present application is to provide a unimolecular micelle aqueous solution, which is self-assembled from a linear amphiphilic multi-block copolymer in an aqueous phase, and the amphiphilic polyether ester multi-block copolymer has a high molecular weight and a large number of blocks, and its chemical structural formula is as follows:

[0010] ,

[0011] Wherein, a is any integer from 2 to 4, b is any integer from 2 to 11, c is any integer from 22 to 90, m is any integer from 1 to 3, and n is any integer greater than 2.

[0012] In an embodiment of the present application, the particle size of the micelles in the monomolecular micelle solution is smaller than the particle size of the polyether ester multi-block copolymer in the good solvent; and the monomolecular micelles are formed.

[0013] The good solvent is one or more of tetrahydrofuran, N,N-dimethylformamide and dimethyl sulfoxide.

[0014] In an embodiment of the present application, the concentration of the monomolecular micelle solution is 0.1 mg / mL to 10 mg / mL.

[0015] In an embodiment of the present application, the amphiphilic polyether ester multi-block copolymer comprises a polyether block and a polyester block; the polyether block is a polyethylene glycol block; and the polyester block is an aliphatic polyester block.

[0016] The mass ratio of the polyether block to the polyester block in the amphiphilic polyether ester multi-block copolymer is 2:1 to 5:1.

[0017] The amphiphilic polyether ester multi-block copolymer has degradable properties.

[0018] In an embodiment of the present application, the molecular weight of the macromolecular initiator polyethylene glycol is 2 kg / mol to 4 kg / mol.

[0019] In an embodiment of the present application, the molecular weight of the multi-block copolymer is 20 kg / mol to 100 kg / mol.

[0020] In an embodiment of the present application, the aqueous phase is water and / or deuterium water.

[0021] A second object of the present application is to provide a preparation method of the monomolecular micelle aqueous solution, comprising the following steps: dissolving the amphiphilic polyether ester multi-block copolymer in a good solvent to obtain a polyether ester multi-block copolymer solution; slowly adding an aqueous phase to the obtained polyether ester multi-block copolymer solution to dilute and self-assemble into monomolecular micelles; removing the good solvent in the solution by dialysis to obtain a monomolecular micelle solution.

[0022] Alternatively, the amphiphilic polyether ester multi-block copolymer is dissolved in a good solvent to obtain a polyether ester multi-block copolymer solution; the obtained polyether ester multi-block copolymer solution is added dropwise into an aqueous phase to self-assemble into monomolecular micelles; and the good solvent in the solution is removed by dialysis to obtain a monomolecular micelle aqueous solution.

[0023] In one embodiment of the present application, the good solvent is one or more of N,N-dimethylformamide, tetrahydrofuran and dimethyl sulfoxide; the good solvent is miscible with water;

[0024] The concentration of the polyether ester multi-block copolymer in the polyether ester multi-block copolymer solution is 1 mg / mL to 100 mg / mL.

[0025] A third object of the present application is to provide an application of the monomolecular micelle aqueous solution in drug loading, the monomolecular micelle aqueous solution is loaded with a hydrophobic drug to obtain a drug-loaded monomolecular micelle solution, and the monomolecular micelle aqueous solution has a solubilizing effect on the hydrophobic drug.

[0026] In one embodiment of the present application, the drug-loaded monomolecular micelle aqueous solution does not release the drug upon dilution, and has stability.

[0027] In one embodiment of the present application, the drug-loaded monomolecular micelle aqueous solution releases the hydrophobic drug under the action of an enzyme; and the monomolecular micelles in the monomolecular micelle solution have biodegradability.

[0028] In the prior art, the polymer used to prepare the monomolecular micelles is usually a dendritic polymer, and such a polymer and the monomolecular micelles prepared therefrom usually have problems such as complex synthesis steps, low yield, difficulty in degradation in the human body, and too slow drug release speed.

[0029] The above technical solution of the present application has the following advantages compared with the prior art:

[0030] 1. The present application provides a monomolecular micelle aqueous solution, a preparation method and an application thereof. The monomolecular micelles prepared by the present application have good stability in water, and the micelles do not dissociate with the change of concentration, so the loaded drug is not released upon dilution. The micelles formed by the self-assembly of traditional two-block and three-block copolymers dissociate upon dilution, resulting in drug release.

[0031] 2. The particle size of the monomolecular micelles of the present application is smaller than that of the multi-block copolymers in a good solvent, and the average hydrodynamic diameter thereof is usually less than 30 nanometers, so the monomolecular micelles are easy to accumulate at the tumor site, achieving passive targeting treatment.

[0032] 3. The monomolecular micelles of the present application are prepared from aliphatic polyether ester multi-block copolymers, and both the aliphatic polyester and the aliphatic polyether block have good biocompatibility and can be used in vivo.

[0033] 4. The monomolecular micelles prepared by the present application have good solubilizing capacity for drugs that are insoluble in water.

[0034] 5. The monomolecular micelles prepared by this invention are biodegradable, and the monomolecular micelles loaded with hydrophobic drugs can release the hydrophobic drugs under the action of lipases. Attached Figure Description

[0035] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0036] Figure 1 This is a schematic diagram of the assembly of single-molecule micelles in this invention;

[0037] Figure 2 The results of dynamic light scattering tests are for the single-molecule micelle solution M-1 prepared in Example 1 of this invention.

[0038] Figure 3 The results of dynamic light scattering tests of the amphiphilic polyether ester multiblock copolymer mBCP-1 prepared in Example 1 of this invention in its good solvent tetrahydrofuran;

[0039] Figure 4 The transmission electron microscope test results are those of the single-molecule micelle solution M-1 prepared in Example 1 of this invention;

[0040] Figure 5 The NMR diffusion sequence spectrum of the amphiphilic polyether ester multiblock copolymer mBCP-1 in its good solvent deuterated chloroform is shown in Example 2 of this invention.

[0041] Figure 6 The nuclear magnetic diffusion sequence spectrum of the monomolecular micelle solution M-2 prepared from the amphiphilic polyether ester multiblock copolymer mBCP-1 in its selective solvent deuterium water in Example 2 of the present invention;

[0042] Figure 7 The results of dynamic light scattering tests are for the single-molecule micelle solution M-3 prepared in Example 3 of this invention;

[0043] Figure 8 The results of dynamic light scattering tests are for the single-molecule micelle solution M-4 prepared in Example 4 of this invention.

[0044] Figure 9 The results of dynamic light scattering tests are for the single-molecule micelle solution M-5 prepared in Example 5 of this invention.

[0045] Figure 10 The results of dynamic light scattering tests are for the single-molecule micelle solution M-6 prepared in Example 6 of this invention.

[0046] Figure 11 The results of dynamic light scattering tests are for the single-molecule micelle solution M-7 prepared in Example 7 of this invention.

[0047] Figure 12 The dynamic light scattering test result of the monomolecular micelle solution M-8 prepared in Example 8 of the present application;

[0048] Figure 13 The UV-visible absorption spectrum test result of the solution after mixing curcumin with the monomolecular micelle solution M-1 and deionized water in Test Example 1 of the present application;

[0049] Figure 14 The dynamic light scattering test result of the monomolecular micelle solution M-1 before and after solubilizing curcumin in Test Example 1 of the present application;

[0050] Figure 15 The UV-visible absorption spectrum test result of the solution after continuously diluting the solution after drug loading of the monomolecular micelle M-1 in Test Example 1 of the present application;

[0051] Figure 16 The UV-visible absorption spectrum test result of the solution after drug loading of the monomolecular micelle solution M-4 in Test Example 2 of the present application;

[0052] Figure 17 The dynamic light scattering test result of the triblock copolymer micelle Tri-M prepared in Comparative Example 1 of the present application;

[0053] Figure 18 The UV-visible absorption spectrum test result of the solution after drug loading of the triblock copolymer micelle Tri-M in Test Example 3 of the present application and the solution after diluting the same. DETAILED DESCRIPTION

[0054] The present application will be further described in conjunction with the drawings and specific examples so that those skilled in the art can better understand the present application and implement it. However, the examples are not intended to limit the present application.

[0055] The experimental methods used in the following examples are conventional methods unless otherwise specified, and the materials, reagents, etc. used are commercially available unless otherwise specified.

[0056] The CAS number of the organic reagents used in the present application is shown in the following table:

[0057] Table 1

[0058]

[0059] In the following embodiments of the present application, the amphiphilic polyether ester multi-block copolymer is prepared by a ring-opening condensation cascade polymerization reaction, and the specific reference is patent CN115260460A - A copolyester and a preparation method thereof. The general synthesis method is as follows: the aliphatic cyclic ester (musk T, cyclic oligomeric butylene succinate or cyclic oligomeric ethylene glycol adipate), polyethylene glycol and catalyst (tetrabutyl titanate) are mixed, nitrogen is passed, heated to 220 °C-240 °C, continue to pass nitrogen or vacuum polymerization for a certain time, and the amphiphilic polyether ester multi-block copolymer is obtained.

[0060] In the following embodiments of the present application, the single-molecule micelles are prepared by solvent exchange method.

[0061] In the following embodiments of the present application, the single-molecule micelles are tested by dynamic light scattering (DLS) using a Brookhaven BI-200SM laser light scattering instrument (temperature: 25 °C, wavelength: 637 nm, time: 10-15 min).

[0062] In the following embodiments of the present application, the diffusion coefficient of the amphiphilic polyether ester multi-block copolymer in a good solvent (deuterated chloroform) and a selective solvent (deuterated water) is tested by nuclear magnetic resonance diffusion ordered spectroscopy (DOSY) using an Agilent Direct-Drive II 600 MHz (temperature: 25 °C).

[0063] In the following embodiments of the present application, the morphology of the single-molecule micelles is determined by transmission electron microscopy (TEM) using a Hitachi HT7700 transmission electron microscope.

[0064] In the following embodiments of the present application, the ultraviolet-visible absorption spectrum of the single-molecule micelle solubilized sample is tested by ultraviolet-visible absorption spectrometer (UV-vis) using a Shimadzu UV-1800 spectrophotometer (temperature: room temperature).

[0065] Example 1

[0066] This embodiment provides a single-molecule micelle aqueous solution and a preparation method thereof. The polyether ester multi-block copolymer mBCP-1 sample used is obtained by ring-opening condensation cascade polymerization of polyethylene glycol (PEO, molecular weight 2000 g / mol) and musk T, with a molecular weight of 68.9 kg / mol, a weight ratio of polyether to polyester of 3.5:1, and an average block number of 55 (n = 27). The specific process is as follows:

[0067] 100 mg of mBCP-1 sample was weighed and dissolved in 10 mL of N,N-dimethylformamide (DMF) overnight. With stirring, 40 mL of deionized water was added dropwise to the DMF solution containing the polymer at a rate of 6 mL / h to prepare a micelle solution with a concentration of 2 mg / mL. The prepared micelle solution was dialyzed in deionized water, with the deionized water changed every 12 h for a total of 4 days. After dialysis, monomolecular micelle solution M-1 was obtained (see schematic diagram of monomolecular micelle assembly as shown). Figure 1 (As shown).

[0068] Figure 2 The results are from DLS analysis of the monomolecular micelle solution M-1. The average hydrodynamic diameter of the prepared monomolecular micelles is 13.6 nm.

[0069] Figure 3 The particle size of mBCP-1, measured by DLS in the good solvent tetrahydrofuran (THF), is 20.4 nm, which is larger than the diameter of the micelles in M-1. Since polymers are dispersed as monomolecules in a good solvent in dilute solutions, this indicates that monomolecular micelles are formed in water.

[0070] Figure 4 These are the TEM test results of the single-molecule micelle solution M-1. The average diameter of the prepared single-molecule micelles is about 13 nm.

[0071] Example 2

[0072] This embodiment provides a monomolecular micelle aqueous solution and its preparation method. The preparation method of micelles provided in this embodiment is similar to that in Example 1, except that deuterium water is used instead of deionized water to obtain monomolecular micelle deuterium aqueous solution M-2.

[0073] Figure 5 The diagram shows the DOSY curve of mBCP-1 in its good solvent, deuterated chloroform, with a measured diffusion coefficient of 0.561 × 10⁻⁶. -10 m 2 / s, from the Stokes-Einstein equation (D = kT / 6πηR h The hydrodynamic radius is 6.1 nm, where k is the Boltzmann constant, T is the thermodynamic temperature, and η is the viscosity of the solvent.

[0074] Figure 6 The image shows the DOSY diagram of mBCP-1 in its selective solvent, deuterium water, with a measured diffusion coefficient of 0.214 × 10⁻⁶. -10 m 2The hydrodynamic radius of the sample is 5.8 nm, obtained from the Stokes-Einstein equation. This is smaller than the hydrodynamic radius of the sample in the good solvent deuterated chloroform, indicating that the sample formed in deuterated water is a monomolecular micelle.

[0075] Example 3

[0076] This embodiment provides a monomolecular micelle aqueous solution and its preparation method. The preparation method of the micelles provided in this embodiment is similar to that in Example 1, except that: a polyether ester multiblock copolymer mBCP-2 is used instead of mBCP-1; a monomolecular micelle solution M-3 is prepared.

[0077] The preparation method of the polyether ester multiblock copolymer mBCP-2 sample is similar to that of mBCP-1, except that the polymerization time is shorter than that of mBCP-1. The resulting polyether ester multiblock copolymer has a molecular weight of 32.4 kg / mol and an average number of blocks of 27 (n = 13).

[0078] Figure 7 The results are from the DLS test of the monomolecular micelle solution M-3, showing that the average diameter of the prepared monomolecular micelles is 14.4 nm.

[0079] Example 4

[0080] This embodiment provides a single-molecule micelle aqueous solution and its preparation method. The preparation method of the micelles provided in this embodiment is similar to that in Example 1, except that: a polyether ester multiblock copolymer mBCP-3 is used instead of mBCP-1; the amount of mBCP-3 sample added is 250 mg; and a single-molecule micelle solution M-4 with a concentration of 5 mg / mL is obtained.

[0081] The preparation method of polyether ester multiblock copolymer mBCP-3 is similar to that of mBCP-1, with the only difference being that the mBCP-3 sample was obtained by ring-opening-condensation cascade polymerization of polyethylene glycol (PEO, molecular weight 3000 g / mol) and musk T, with a molecular weight of 63.5 kg / mol, a polyether to polyester weight ratio of 4.5:1, and an average number of blocks of 35 (n = 17).

[0082] Figure 8 The results are from the DLS test of the monomolecular micelle solution M-4. The average diameter of the prepared monomolecular micelles is 26.8 nm.

[0083] Example 5

[0084] This embodiment provides a single-molecule micelle aqueous solution and its preparation method. The preparation method of the micelles provided in this embodiment is similar to that in Example 1, except that the solvent N,N-dimethylformamide (DMF) is replaced with dimethyl sulfoxide (DMSO); the amount of mBCP-1 sample added is 25 mg; thus, a single-molecule micelle solution M-5 with a concentration of 0.5 mg / mL is prepared.

[0085] Figure 9 The results are from the DLS test of the monomolecular micelle solution M-5, showing that the average diameter of the prepared monomolecular micelles is 13.8 nm.

[0086] Example 6

[0087] This embodiment provides a monomolecular micelle aqueous solution and its preparation method. The preparation method of the micelles provided in this embodiment is similar to that in Example 1, except that: a polyether ester multiblock copolymer mBCP-4 is used instead of mBCP-1; and the solvent N,N-dimethylformamide (DMF) is replaced with tetrahydrofuran (THF). A monomolecular micelle solution M-6 with a concentration of 2 mg / mL is thus prepared.

[0088] The preparation method of the mBCP-4 sample used was similar to that of mBCP-1, with the only difference being that the molecular weight of the obtained polymer was 80.3 kg / mol, the weight ratio of polyether to polyester was 3:1, and the average number of blocks was 61 (n = 30).

[0089] Figure 10 The results are from the DLS test of the monomolecular micelle solution M-6, showing that the average diameter of the prepared monomolecular micelles is 12.5 nm.

[0090] Example 7

[0091] This embodiment provides a monomolecular micelle aqueous solution and its preparation method. The preparation method of the micelles provided in this embodiment is similar to that in Example 1, except that a polyether ester multiblock copolymer mBCP-5 is used instead of mBCP-1. A monomolecular micelle solution M-7 with a concentration of 2 mg / ml is prepared.

[0092] The preparation method of mBCP-5 is similar to that of mBCP-1, with the only difference being that the mBCP-5 sample is obtained by ring-opening-condensation cascade polymerization of polyethylene glycol (PEO, molecular weight 2000 g / mol) and cyclic oligobutyl succinate, with a molecular weight of 45.0 kg / mol, a polyether to polyester weight ratio of 3.5:1, and an average number of blocks of 35 (n = 17).

[0093] Figure 11 The results are from the DLS test of the monomolecular micelle solution M-7, showing that the average diameter of the prepared monomolecular micelles is 13.6 nm.

[0094] Example 8

[0095] This embodiment provides a monomolecular micelle aqueous solution and its preparation method. The preparation method of the micelles provided in this embodiment is similar to that in Example 1, except that a polyether ester multiblock copolymer mBCP-6 is used instead of mBCP-1. A monomolecular micelle solution M-8 with a concentration of 2 mg / mL is obtained.

[0096] The preparation method of mBCP-6 is similar to that of mBCP-1, with the only difference being that the mBCP-6 sample is obtained by ring-opening-condensation cascade polymerization of polyethylene glycol (PEO, molecular weight 1500 g / mol) and cyclic oligomeric polyethylene adipate, with a molecular weight of 55.5 kg / mol, a polyether to polyester weight ratio of 4:1, and an average number of blocks of 61 (n = 30).

[0097] Figure 12 The figure shows the DLS test results of the monomolecular micelle solution M-8. As can be seen from the figure, the average diameter of the prepared monomolecular micelles is 7.9 nm.

[0098] Test Example 1

[0099] This test case demonstrates the solubilizing ability of monomolecular micelle solutions for hydrophobic drugs and the stability of drug-loaded monomolecular micelles under dilution conditions, as detailed below:

[0100] Take 10 mL of the single-molecule micelle solution M-1 sample from Example 1 and 10 mL of deionized water as a control sample, add 0.5 mg of curcumin to each, and stir at room temperature for 24 h. Measure the UV-vis absorption spectra of the corresponding solutions, as shown below. Figure 13 As shown in the figure, an absorption peak of curcumin appeared in the solution of the single-molecule micelle sample, with a concentration of approximately 4.78 μg / mL. However, curcumin is insoluble in water and did not show a corresponding absorption peak, indicating that the prepared single-molecule micelles have excellent solubilizing ability for the hydrophobic drug curcumin.

[0101] Figure 14 The figure shows the DLS test results of the single-molecule micelle solution M-1 loaded with curcumin. As can be seen from the figure, the average diameter of the single-molecule micelles after loading with curcumin is 14.2 nm, which is not much different from the average diameter before solubilization (13.6 nm).

[0102] The stability of the curcumin-loaded single-molecule micelle solution M-1 was investigated by dilution and UV-vis testing. Figure 15These are the UV-Vis curves of the samples before and after dilution. The absorbance before dilution was 0.105. After a two-fold dilution, the theoretical absorbance calculated based on the concentration dilution was 0.0525, and the actual absorbance was 0.0521. After a five-fold dilution, the theoretical absorbance was 0.0210, and the actual absorbance was 0.0199. The measured absorbance after dilution is close to the theoretical absorbance, indicating that the single-molecule micelles loaded with curcumin do not release the loaded drug upon dilution.

[0103] Test Example 2

[0104] This test case demonstrates the release of hydrophobic drugs by unimolecular micelle solutions under enzymatic action, as detailed below:

[0105] Take the single-molecule micelle solution M-4 sample from Example 4, add 0.5 mg of curcumin to it and stir to solubilize it for 2 h, then filter to remove free curcumin and add lipase PS with an enzyme concentration of 1 mg / mL, and place it in a shaker at 45 °C for 24 h.

[0106] Figure 16 The figures show the UV-vis values ​​at 0 h and 24 h after the addition of lipase. As can be seen from the figure, after 24 h of lipase addition, the UV absorption curve of curcumin decreased significantly (the peak value decreased from 0.609 to 0.307), indicating that the monomolecular micelles were degraded under the action of the enzyme, thereby releasing curcumin.

[0107] Comparative Example 1

[0108] This comparative example provides an aqueous solution of triblock copolymer micelles. The triblock copolymer tri-BCP sample used was obtained by ring-opening polymerization of polyethylene glycol (PEO, molecular weight 2000 g / mol) and musk T, with a molecular weight of 2.6 kg / mol and a polyether to polyester weight ratio of 3.5:1. Its structure is similar to mBCP-1, but it is a triblock copolymer (i.e., n = 1). The triblock copolymer micelle solution tri-M with a concentration of 2 mg / mL was prepared according to the micelle preparation method in Example 1.

[0109] Figure 17 The figure shows the DLS test results of tri-M micelles prepared from the tri-BCP copolymer sample. As can be seen from the figure, the average diameter of the prepared micelles is 79.6 nm, which is much larger than the particle size in a good solvent, indicating that a micelle solution composed of aggregates of multiple molecules was formed.

[0110] Test Example 3

[0111] The solubilizing ability of the micelle solution prepared from the tri-BCP copolymer in Comparative Example 1 for hydrophobic drugs and the stability of the micelles under dilution conditions after drug loading are as follows:

[0112] Take 10 mL of the micelle solution tri-M sample from Comparative Example 1, add 0.5 mg of curcumin, and stir at room temperature for 24 h. Measure the UV-vis absorption spectrum of the solution, as shown below. Figure 18 As shown in the figure, an absorption peak of curcumin appeared in the Tri-M micelle sample solution, with a concentration of 3.53 μg / mL, indicating that the prepared micelles have a solubilizing effect on the hydrophobic drug curcumin.

[0113] The above solution was diluted and UV-vis tests were performed. The UV-vis curves of the samples before and after dilution are shown below. Figure 18 As shown, the absorbance before dilution was 0.488. After a two-fold dilution, the theoretical absorbance should be 0.244, but the actual absorbance was 0.202. After a five-fold dilution, the theoretical absorbance should be 0.0976, but the actual absorbance was 0.0637. The actual absorbance after dilution is less than the theoretical absorbance calculated based on concentration dilution, indicating that after the micelles assembled from the triblock copolymer are loaded with curcumin, the micelles will dissociate upon dilution, thereby releasing the loaded drug.

[0114] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A single-molecule micelle aqueous solution, characterized in that, The monomolecular micelle aqueous solution is formed by the self-assembly of an amphiphilic polyether ester multiblock copolymer in an aqueous phase; the chemical structural formula of the amphiphilic polyether ester multiblock copolymer is as follows: ， Where a is any integer from 2 to 4, b is any integer from 2 to 11, c is any integer from 22 to 90, m is any integer from 1 to 3, and n is any integer greater than 2.

2. The unimolecular micelle aqueous solution according to claim 1, characterized in that, The particle size of the micelles in the monomolecular micelle solution is smaller than that of the polyether ester multiblock copolymer in a good solvent. The good solvent is one or more of tetrahydrofuran, N,N-dimethylformamide, and dimethyl sulfoxide.

3. The unimolecular micelle aqueous solution according to claim 1, characterized in that, The concentration of the monomolecular micelle solution is 0.1 mg / mL to 10 mg / mL.

4. The unimolecular micelle solution according to claim 1, characterized in that, The amphiphilic polyether ester multiblock copolymer includes polyether blocks and polyester blocks; the polyether blocks are polyethylene glycol blocks; and the polyester blocks are aliphatic polyester blocks. The mass ratio of polyether blocks to polyester blocks in the amphiphilic polyether ester multiblock copolymer is 2:1 to 5:1; The amphiphilic polyether ester multiblock copolymer has biodegradable properties.

5. The unimolecular micelle solution according to claim 1, characterized in that, The aqueous phase is water and / or deuterated water.

6. The method for preparing a single-molecule micelle aqueous solution according to any one of claims 1-5, characterized in that, The process includes the following steps: dissolving the amphiphilic polyether ester multiblock copolymer in a good solvent to obtain a polyether ester multiblock copolymer solution; slowly adding an aqueous phase to dilute the obtained polyether ester multiblock copolymer solution to self-assemble into monomolecular micelles; and removing the good solvent from the solution by dialysis to obtain a monomolecular micelle solution. Alternatively, the amphiphilic polyether ester multiblock copolymer is dissolved in a good solvent to obtain a polyether ester multiblock copolymer solution; the obtained polyether ester multiblock copolymer solution is added dropwise to an aqueous phase, where it self-assembles into monomolecular micelles; the good solvent in the solution is removed by dialysis to obtain an aqueous solution of monomolecular micelles.

7. The method for preparing a single-molecule micelle aqueous solution according to claim 6, characterized in that, The good solvent is one or more of N,N-dimethylformamide, tetrahydrofuran, and dimethyl sulfoxide; The concentration of the polyether ester multiblock copolymer in the polyether ester multiblock copolymer solution is 1 mg / mL to 100 mg / mL.

8. The use of the monomolecular micelle solution according to any one of claims 1-5 in drug loading, characterized in that, A hydrophobic drug is loaded onto a monomolecular micelle aqueous solution to obtain a drug-loaded monomolecular micelle solution, wherein the monomolecular micelle aqueous solution has a solubilizing effect on the hydrophobic drug.

9. The application according to claim 8, characterized in that, The drug-loaded monomolecular micelle aqueous solution does not release the drug upon dilution, thus exhibiting stability.

10. The application according to claim 8, characterized in that, The drug-loaded monomolecular micelle aqueous solution releases the hydrophobic drug under the action of enzymes; the monomolecular micelles in the monomolecular micelle solution are biodegradable.

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