Preparation and application of tumor-targeted boron-rich polypeptide micelle delivery system

Abstract

The invention discloses preparation and application of a tumor-targeted boron-rich polypeptide micelle delivery system, and belongs to the technical field of nano-drug delivery systems. The invention designs and constructs a novel boron delivery nano system based on polypeptide micelles, the system is composed of three parts of a carrier module, a boron source module and a targeting module, a polyethylene glycol-b-polylysine (PEG-b-PLL) amphiphilic block copolymer is used as a carrier, abundant amino active sites of a side chain of a polylysine chain segment are fully utilized, and the targeting effect is improved. High-density covalent coupling of the boron source is realized; carborane is selected as a boron source, the content of boron atoms in the molecular structure reaches 75% (mass fraction), and the boron loading amount of the nano-micelle is remarkably increased; and different targeting ligands are modified by utilizing the terminal functionalization characteristic of polyethylene glycol, so that the specific enrichment of the nano boron delivery system in various tumor tissues is realized. The polypeptide micelle delivery system has the characteristics of high boron loading efficiency, excellent tumor targeting property and the like, and has a huge application prospect in the field of boron neutron capture therapy.

Description

Technical Field

[0001] The present invention belongs to the technical field of nano drug delivery systems, and particularly relates to the preparation of a tumor-targeted boron-rich polypeptide micelle delivery system and its application in the preparation of anti-tumor drugs. Background Art

[0002] Head and neck squamous cell carcinomas (HNSCCs) are highly invasive malignant tumors originating from the mucosal epithelium of the oral cavity, pharynx, and larynx, ranking sixth among solid tumors in global incidence. The clinical treatment of this disease faces many challenges: First, due to the complex anatomy of the head and neck and the highly invasive nature of the tumor, radical resection is difficult to achieve surgically. Second, although immune checkpoint inhibitors can prolong the survival of patients with recurrent / metastatic disease, the complete remission rate remains suboptimal due to the highly suppressive tumor immune microenvironment. Furthermore, while traditional chemotherapy can control the disease to a certain extent, its severe toxic side effects greatly limit its clinical application. Therefore, there is an urgent need to develop new treatment strategies that are both safe and effective.

[0003] Boron neutron capture therapy (BNCT) is a binary radiotherapy method based on the boron neutron capture reaction. Its treatment principle is: the stable isotope enriched in the tumor site 10 After absorbing thermal neutrons, B undergoes nuclear fission reaction to produce high-energy α particles ( 4 He 2+ )and 7 Li 3+ Particles, the effective range of these charged particles is limited to the scale of a single cell (d < 10μm), which theoretically achieves precise killing of tumor cells. Compared with traditional radiotherapy, BNCT shows unique advantages in the treatment of head and neck tumors. On the one hand, thermal neutron beams have excellent tissue penetration and can effectively act on deep lesions; on the other hand, through the tumor-targeted accumulation of boron delivery agents, high-precision killing of tumors is achieved, significantly reducing damage to surrounding normal tissues. At present, this technology has entered the clinical trial stage in many countries such as Japan and Finland, showing good application prospects.

[0004] Improving boron delivery efficiency is one of the key factors in enhancing the therapeutic effect of BNCT. The core lies in optimizing the boron loading and tumor targeting of the delivery system. At present, nanoboron delivery carriers are mainly based on two major systems: inorganic materials (such as boron nitride nanosheets, mesoporous silica, etc.) and organic materials (such as liposomes, dendrimers, etc.). Compared with inorganic materials, organic nanocarriers have more advantages in achieving high boron loading and active targeting due to their controllable chemical structure and rich surface functional groups. However, some organic carrier materials still have problems such as difficult degradation in the body, resulting in carrier accumulation or the production of toxic metabolites, which seriously restricts their clinical translation potential.

[0005] Polypeptide nanomaterials have become extremely promising boron delivery carriers due to their unique biological properties. As biodegradable materials constructed from natural amino acids, polypeptides not only have excellent biocompatibility, but their degradation products are all small molecules that can be metabolized by the body, fundamentally solving the biosafety issues of traditional carriers. More importantly, the abundant side chain active groups (such as amino and carboxyl groups) in the molecular structure of polypeptides provide ideal reaction sites for high-density covalent coupling of boron-containing compounds. By precisely controlling the block length and side chain functional groups of polypeptides, intelligent nanomicelle systems with multiple response characteristics can be constructed, which can not only achieve high boron loading, but also significantly improve the boron delivery efficiency of tumor tissues through active-passive targeting synergistic mechanisms.

[0006] In order to achieve the selective enrichment of nanoboron agents at the tumor site, the introduction of active targeting strategies is particularly critical. Polypeptide micelle delivery systems are easy to functionalize on the surface, and multiple targeting synergistic effects can be achieved by modifying specific targeting molecules (peptides, antibodies, small molecule ligands, etc.). Typical targeting strategies include utilizing the high affinity between cyclic RGD (cRGD) peptides and internalized RGD (iRGD) peptides and αVβ3 integrin receptors overexpressed on the surface of some solid tumor cells to achieve tumor targeting; utilizing Evans blue, 4-(p-iodophenylbutyric acid derivatives), hydrophobic porphyrins and related chromophores to specifically bind to some serum proteins (such as albumin and lipoproteins), thereby promoting binding to receptors overexpressed in tumor cells (GP60 and LDL receptors), thereby improving the drug accumulation effect in the tumor area.

[0007] However, to date, no research has been reported on the development of tumor-targeted boron-rich peptide micelle delivery systems based on the excellent biocompatibility, degradability and high boron loading capacity of peptide micelles, combined with the active-passive targeting synergistic mechanism, to achieve efficient enrichment of boron agents in the tumor area and improve the therapeutic effect of BNCT. Summary of the Invention

[0008] In view of this, the purpose of the present invention is to provide the preparation of a tumor-targeted boron-rich polypeptide micelle delivery system and its application in the preparation of anti-tumor drugs. The present invention uses polyethylene glycol-b-polylysine (PEG-b-PLL) amphiphilic block copolymer as a nanocarrier to construct a tumor-targeted boron-rich polypeptide micelle delivery system, which solves the technical problems of low boron loading efficiency and poor tumor specificity of existing nanodelivery systems, showing potential clinical application value in the field of boron neutron capture therapy.

[0009] In order to achieve the above object, the present invention provides the following technical solutions:

[0010] In the first aspect, the present invention provides a tumor-targeted boron-rich peptide carrier material, the structural formula of which is as follows:

[0011]

[0012] Where R1 is

[0013] R2 is a carboxylated carborane molecule, z is an integer from 0 to 10;

[0014] R3 is the targeting molecule;

[0015] x is a positive integer from 45 to 150;

[0016] y is a positive integer ranging from 5 to 35.

[0017] Based on the above technical solution, further, z is an integer from 2 to 6, x is a positive integer from 100 to 120, and y is a positive integer from 15 to 25.

[0018] Based on the above technical solution, further, R3 is a targeting molecule including iRGD, cRGD, Angiopep-2, folic acid, iodophenylbutyric acid and pyropheophorbide a.

[0019] Based on the above technical solution, further, R2 is 3-(1,2-dicarbonadecaborane)propionic acid.

[0020] In a second aspect, the present invention provides a method for preparing the above-mentioned tumor-targeting boron-rich peptide carrier material, comprising the following steps:

[0021] (1) Synthesis of N6-Lys-NCA: N6-Lys-Cbz was added to a mixed solvent of anhydrous tetrahydrofuran and propylene oxide, stirred evenly, and triphosgene was added. The mixture was stirred at 40-70°C under inert gas protection until the reaction was complete to obtain N6-Lys-NCA.

[0022] (2) Synthesis of block copolymer PEG-b-PLL: PEG-NH2 was dissolved in a NaHCO3 solution at pH 8-9, and N6-Lys NCA obtained in step (1) was added. The mixture was stirred in an ice bath for 0.5-2 h, and then vigorously stirred at room temperature for 20-48 h to obtain PEG-b-PLL-Cbz. PEG-b-PLL-Cbz was dissolved in trifluoroacetic acid, and an acetic acid solution containing 30-40% by volume of hydrobromic acid was added. The mixture was stirred in an ice bath for 1-3 h, dialyzed, and lyophilized to obtain a PEG-b-PLL solid powder.

[0023] (3) Synthesis of block copolymer PEG-b-PLCB: Carboxylated carborane molecules, 1-hydroxybenzotriazole (HOBT), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI) and N,N-diisopropylethylamine (DIEA) were added to an eggplant-shaped flask, and an organic solvent was added. After stirring for 20 to 60 minutes, the PEG-b-PLL obtained in step (2) was added, and the mixture was stirred at room temperature for 20 to 48 hours. After dialysis, the PEG-b-PLCB solid powder was obtained after freeze-drying.

[0024] (4) The targeting molecule connected with an alkynyl group and the PEG-b-PLCB obtained in step (3) were added to DMF to dissolve, and a catalyst solution containing CuI was added. The mixture was stirred at room temperature for more than 24 hours, and freeze-dried to obtain a tumor-targeted boron-rich polypeptide carrier material.

[0025] Based on the above technical solution, further, the inert gas includes nitrogen, helium, neon, and argon.

[0026] Based on the above technical solution, further, the molar ratio of N6-Lys-Cbz, triphosgene and propylene oxide described in step (1) is 1: (0.2~0.7): (5~10); the volume ratio of anhydrous tetrahydrofuran and propylene oxide is (20~5): 1.

[0027] Based on the above technical solution, further, in step (1), the reaction temperature is 40-60° C., and the reaction time is 1-4 h.

[0028] Based on the above technical solution, further, the PEG-NH2 described in step (2) includes MPEG-NH2 or N3-PEG-NH2, and the molecular weight of PEG is 200 to 20,000.

[0029] Based on the above technical solution, further, the molar ratio of N6-Lys NCA and PEG-NH2 in step (2) is (5-25):1; the molar ratio of PEG-b-PLL-Cbz and hydrobromic acid is 1:(1-1.5).

[0030] Based on the above technical solution, further, the organic solvent described in step (3) includes N,N-dimethylformamide and N,N-dimethylacetamide.

[0031] Based on the above technical solution, further, in step (3), the feeding molar ratio of carboxylated carborane molecules, HOBT, EDCI, DIEA and PEG-b-PLL is (5-25): (6-30): (6-30): (12.5-62.5): 1.

[0032] Based on the above technical solution, further, the preparation of the carboxylated carborane molecule described in step (3) includes the following steps:

[0033] 1) Add 2-3 g of 4-pentynoic acid and 4-6 g of K2CO3 to an eggplant-shaped flask, add DMF, stir evenly, then add 3-5 mL of benzyl bromide, and stir at room temperature under inert gas for 20-30 h to obtain benzyl 4-pentynoate;

[0034] 2) Add 2-3 g of benzyl 4-pentynoate to a three-necked flask, add 20-40 mL of chlorobenzene and 2-5 mL of N,N-dimethylaniline, add 1-2 g of decaborane, and react in a microwave reactor at 130-140° C. under inert gas protection and air condensation reflux for 10-30 minutes to obtain benzyl 3-(1,2-dicarbonadecaborane)propionate;

[0035] 3) Add 1-2 g of benzyl 3-(1,2-dicarbonadecaborane)propionate and 100-200 mg of palladium on carbon to an eggplant-shaped flask, add ethanol and acetic acid, and stir the reaction at room temperature in a hydrogen atmosphere for 2-6 h to obtain 3-(1,2-dicarbonadecaborane)propionic acid.

[0036] Based on the above technical solution, further, in step (4), when the targeting molecule is iRGD, 27 mg of 4-pentynoic acid, 56 mg of HOBT, and 63 mg of EDCI are weighed in an eggplant-shaped flask, and DMF is added to dissolve them. Then, 120 μL of DIEA is added and stirred at room temperature for 20 to 30 minutes; 100 mg of iRGD polypeptide is added, and the reaction is stirred at room temperature for more than 24 hours under inert gas protection to obtain iRGD-P; N3-PEG-b-PLCB is weighed. 20 50 mg of RGD-P and 23 mg of iRGD-P were placed in a sealed tube, dissolved in 1 mL of DMF, and 100 μL of CuI catalyst solution was added. The mixture was stirred at room temperature for more than 24 h. The reaction solution was transferred to a dialysis bag with a molecular weight cutoff of 3500 Da, dialyzed in deionized water with stirring for more than 48 h, and freeze-dried.

[0037] When the targeting molecule is iodophenylbutyric acid, 500 mg of iodophenylbutyric acid, 350 mg of HOBT, and 495 mg of EDCI were weighed in an eggplant-shaped flask, dissolved in DMF, and then 761 μL of DIEA was added. The mixture was stirred at room temperature for 20 to 30 minutes. 165 μL of propargylamine was added and the mixture was stirred at room temperature for more than 12 hours. 7 mg of the obtained product and 50 mg of N3-PEG-b-PLCB were taken. 20 In a sealed tube, add 1 mL of DMF to dissolve, add 100 μL of CuI catalyst solution, stir at room temperature for more than 24 h, transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 3500 Da, dialyze in deionized water with stirring for more than 48 h, and freeze-dry to obtain the product;

[0038] When the target molecule is pyropheophorbide a, 80 mg of pyropheophorbide a, 30 mg of HOBT, and 42 mg of EDCI were weighed in an eggplant-shaped flask, dissolved in DMF, and then 64 μL of DIEA was added. The mixture was stirred at room temperature for 20 to 30 min, and then 12 μL of propargylamine was added. The mixture was stirred at room temperature for more than 12 h. 12 mg of the obtained product and 50 mg of N3-PEG-b-PLCB were taken. 20 In a sealed tube, add 1 mL of DMF to dissolve, add 100 μL of CuI catalyst solution, and stir at room temperature for more than 24 h. Transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 3500 Da, dialyze in deionized water with stirring for more than 48 h, and freeze-dry to obtain the product.

[0039] Based on the above technical solution, further, the preparation process of the CuI catalyst solution described in step (4) is as follows: accurately weigh 10 mg of CuI into a 2 mL EP tube, add 1 mL of DMF and 17 μL of DIEA, and mix by ultrasonic vibration.

[0040] In a third aspect, the present invention provides a method for preparing tumor-targeted boron-rich polypeptide micelles, wherein the above-mentioned tumor-targeted boron-rich polypeptide carrier material is dissolved in solvent A, transferred to a dialysis bag with a molecular weight cutoff of 500 to 5000 Da, and dialyzed in solvent B at a stirring speed of 50 to 400 rpm for 12 to 24 hours to obtain tumor-targeted boron-rich polypeptide micelles.

[0041] Based on the above technical solution, further, the concentration of the tumor-targeted boron-rich peptide carrier material in solvent A is 2 to 30 mg / mL, and the solvent A is dimethyl sulfoxide, N,N-dimethylformamide or N-methylpyrrolidone; solvent B is water or phosphate buffer.

[0042] In a fourth aspect, the present invention provides tumor-targeting boron-rich polypeptide micelles obtained by the above preparation method.

[0043] In a fifth aspect, the present invention provides the use of the above-mentioned tumor-targeting boron-rich polypeptide micelles in the preparation of anti-tumor drugs.

[0044] Based on the above technical solution, further, the tumors include head and neck tumors, intracranial tumors, breast cancer, ovarian cancer, liver cancer, kidney cancer, lung cancer, colon cancer, bladder cancer, pancreatic cancer, uterine cancer, gastric cancer, and rectal cancer.

[0045] Based on the above technical solution, further, the head and neck tumors include laryngeal cancer, thyroid cancer, nasopharyngeal cancer, tonsil cancer, lymphoma, and sarcoma; the intracranial tumors include glioma, medulloblastoma, ependymoma, and brain metastasis.

[0046] The present invention has the following advantages and beneficial effects compared to the prior art:

[0047] The tumor-targeted boron-rich peptide micelle delivery system constructed by the present invention uses polyethylene glycol-b-polylysine (PEG-b-PLL) amphiphilic block copolymer as a nanocarrier and has the following significant advantages: (1) high-density covalent coupling of boron source molecules is achieved through the rich amino active sites of the polylysine chain segment side chain; (2) carborane is selected as an efficient boron source, and the boron atomic mass fraction in its molecular structure is as high as 75%, which is one of the highest boron contents among currently known boron-containing compounds; (3) by functionalizing the polyethylene glycol end, various types of targeting ligands can be modified in a targeted manner, significantly improving the active targeting ability of the boron delivery system for multiple cancer types. This delivery system not only has excellent boron loading performance, but also can achieve efficient enrichment of boron agents in tumor areas, showing potential clinical application value in the field of boron neutron capture therapy. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is the synthetic route of the block copolymer N3-PEG-b-PLL.

[0049] Figure 2 The synthetic route of 3-(1,2-dicarbonadecaborane)propionic acid is shown in FIG.

[0050] Figure 3 Block copolymer MPEG-b-PLCB 20 and N3-PEG-b-PLCB 20 Synthesis route diagram.

[0051] Figure 4 The block copolymer iRGD-PEG-b-PLCB 20 Synthesis route diagram.

[0052] Figure 5 The block copolymer IP-PEG-b-PLCB 20 Synthesis route diagram.

[0053] Figure 6 The block copolymer CHPpa-PEG-b-PLCB 20 Synthesis route diagram.

[0054] Figure 7 Block copolymers MPEG-b-PLL-Cbz, MPEG-b-PLCB 20 、iRGD-PEG-b-PLCB 20 、IP-PEG-b-PLCB 20 and CHPpa-PEG-b-PLCB 20 of 1 H NMR spectrum.

[0055] Figure 8 Block copolymers MPEG-b-PLL-Cbz and MPEG-b-PLCB 20 (a) iRGD-PEG-b-PLCB 20 (b) IP-PEG-b-PLCB 20 (c) and CHPpa-PEG-b-PLCB 20 IR spectrum of (d).

[0056] Figure 9 Boron-rich peptide micelle iRGD-PEG-PLCB for tumor targeting 20 、IP-PEG-PLCB 20 and CHPpa-PEG-PLCB 20 Graph showing changes in hydrated particle size and PDI over seven days.

[0057] Figure 10 Boron-rich peptide micelle iRGD-PEG-PLCB for tumor targeting 20 、IP-PEG-PLCB 20 and CHPpa-PEG-PLCB 20 Figure 2 shows the cytotoxicity evaluation of MOC-1.

[0058] Figure 11 Tumor-targeting boron-rich peptide micelles iRGD-PEG-PLCB with different modification degrees 20 、IP-PEG-PLCB 20 and CHPpa-PEG-PLCB 20 Boron uptake graph in MOC-1 cell line.

[0059] Figure 12 Tumor-targeted boron-rich peptide micelles MPEG-PLCB at different time points 20 、iRGD-PEG-PLCB 20 、IP-PEG-PLCB 20 and CHPpa-PEG-PLCB 20 Boron uptake graph in MOC-1 cell line.

[0060] Figure 13 Fluorescence microscopy monitoring of MOC-1 cell line responses to tumor-targeting boron-rich peptide micelles MPEG-PLCB 20 @CHPpa、iRGD-PEG-PLCB 20 @CHPpa、IP-PEG-PLCB 20 @CHPpa and CHPpa-PEG-PLCB 20 Uptake diagram.

[0061] Figure 14 Boron-rich peptide micelles MPEG-PLCB for tumor targeting 20 、iRGD-PEG-PLCB 20 、IP-PEG-PLCB 20 and CHPpa-PEG-PLCB 20 Biodistribution profile in tumor-bearing mice.

[0062] Figure 15 Boron-rich peptide micelles MPEG-PLCB for tumor targeting 20 、iRGD-PEG-PLCB 20 、IP-PEG-PLCB 20 and CHPpa-PEG-PLCB 20 Figure 3. Tumor / normal tissue (T / N) and tumor / blood (T / B) profiles at different time points. DETAILED DESCRIPTION

[0063] The present invention is further described below with reference to specific examples, but these examples should not be construed as limiting the present invention.

[0064] Example 1

[0065] The synthesis of block copolymer PEG-b-PLL, the synthesis route is as follows Figure 1 As shown, the following steps are included:

[0066] (1) Synthesis of N6-Lys NCA

[0067] After drying the reaction apparatus, 500 mg of N6-Lys-Cbz was accurately weighed into a 50 mL two-necked flask. 5 mL of anhydrous tetrahydrofuran (THF) and 0.5 mL of propylene oxide (PO) were quickly added. One side of the flask was sealed with a rubber stopper and nitrogen was applied. Stirring was thorough at 50°C. 300 mg of triphosgene was accurately weighed and quickly dissolved in 2 mL of anhydrous THF. The solution quickly turned into a gel and became clear after 10 seconds. Stir at 50°C for 2 hours. After the reaction, the reaction mixture was transferred to a 100 mL eggplant-shaped flask. A large amount of n-hexane was added until precipitation was complete. Ultrasonic agitation was performed and filtered to obtain a white solid. Redissolved in 10 mL of THF, a second precipitation yielded a white solid powder, N6-Lys NCA, with a yield of 88%. The product was stored at low temperature under nitrogen.

[0068] (2) Synthesis of block copolymers MPEG-b-PLL-Cbz and N3-PEG-b-PLL-Cbz

[0069] Prepare a NaHCO3 solution with pH = 8.4 in advance and cool it in an ice bath; accurately weigh 300 mg of MPEG 5000 -NH2 or N3-PEG 5000 -NH2 was added to a Schlenk tube, and 8 mL of pre-cooled NaHCO3 solution was added and stirred in an ice bath. 310 mg of N6-LysNCA was quickly weighed and added to the Schlenk tube. After stirring at 1200 rpm in an ice bath for 2 hours, stirring was continued at room temperature for 24 hours. Upon completion of the reaction, a light blue emulsion was obtained. The liquid was transferred to a dialysis bag with a molecular weight cutoff of 3500 Da and stirred in deionized water for 24 hours, with the water changed every 12 hours. The solid was freeze-dried to obtain a white, fluffy solid (MPEG-b-PLL-Cbz or N3-PEG-b-PLL-Cbz) with an 80% yield. It was stored at low temperature.

[0070] (3) Synthesis of block copolymers MPEG-b-PLL and N3-PEG-b-PLL

[0071] Accurately weigh 500 mg of MPEG-b-PLL-Cbz or N3-PEG-b-PLL-Cbz into a sealed tube and dissolve in 5 mL of trifluoroacetic acid (TFA). Rapidly add 350 μL of 33% HBr / AcOH solution and stir in an ice bath at 50 rpm for 2 hours. After the reaction, spin dry the solvent, reconstitute the solution in a small amount of DMF, transfer the solution to a 1000 Da dialysis tubing, and stir in deionized water for 24 hours, changing the water every 6 hours. Freeze-dry to obtain a white solid powder (MPEG-b-PLL, 73% yield) or N3-PEG-b-PLL, 76% yield). Store at low temperature.

[0072] Example 2

[0073] Synthesis of 3-(1,2-dicarbonadecaborane)propionic acid, the synthetic route is as follows Figure 2 As shown, the following steps are included:

[0074] (1) Synthesis of benzyl 4-pentynoate

[0075] Accurately weigh 2.362g of 4-pentynoic acid and 4.99g of K2CO3 into a 250mL eggplant-shaped flask. Add 48mL of DMF and stir thoroughly. Then, add 3.44mL of benzyl bromide and react at room temperature under nitrogen for 24 hours. After the reaction, spin dry the solvent, add 45mL of deionized water to dissolve the K2CO3, transfer the mixture to a separatory funnel, extract three times with diethyl ether, and dry over anhydrous sodium sulfate. Column chromatography (PE:DCM = 100:1 gradient elution to PE:DCM = 10:1) yields benzyl 4-pentynoate, a colorless, transparent liquid in an 84% yield. Store at low temperature.

[0076] (2) Synthesis of Benzyl 3-(1,2-Dicarbonadecaborane) Ester

[0077] Accurately weigh 2.4 g of benzyl 4-pentynoate into a 100 ml three-necked flask. Add 30 mL of chlorobenzene and 2.4 mL of N,N-dimethylaniline. Quickly weigh 1.878 g of decaborane and add it to the flask. The solution changes from pale yellow to orange-yellow. Place the three-necked flask in a microwave reactor under nitrogen protection and air condensation reflux. Set the reaction conditions to MW 700W and react at 135°C for 17 min. After the reaction is complete, wait until the temperature returns to room temperature and no significant residual odor is present. Remove the solvent and separate by column chromatography (gradient elution with PE:EA = 200:1 to PE:EA = 20:1) to obtain a snowflake-like white solid, benzyl 3-(1,2-dicarbonadecaborane)propionate, in a yield of 79%. Store at low temperature.

[0078] (3) Synthesis of 3-(1,2-dicarbonadecaborane)propionic acid

[0079] Accurately weigh 1.5 g of benzyl 3-(1,2-dicarbonadecaborane) propionate and 150 mg of palladium on carbon (water content 10%) in a 100 mL eggplant-shaped flask. Add 25 mL of ethanol and 4 drops of acetic acid. Replace the atmosphere in the flask with hydrogen. Stir rapidly at room temperature for 4 h. Monitor the reaction by TLC until the end. Filter the residual palladium on carbon in the reaction solution with diatomaceous earth. Dry the solution to obtain a white flaky solid, i.e., 3-(1,2-dicarbonadecaborane) propionic acid, with a yield of 95%. Store at low temperature.

[0080] Example 3

[0081] Block copolymer MPEG-b-PLCB 20 and N3-PEG-b-PLCB 20 The synthesis route is as follows Figure 3 As shown, the following steps are included:

[0082] Accurately weigh 272 mg of 3-(1,2-dicarbonadecaborane)propionic acid, 255 mg of 1-hydroxybenzotriazole (HOBT), and 287 mg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI) in a 50 mL eggplant-shaped flask. Dissolve thoroughly in 10 mL of DMF, then add 549 μL of N,N-diisopropylethylamine (DIEA). Stir at room temperature for 30 minutes. Accurately weigh 384 mg of MPEG-b-PLL or N3-PEG-b-PLL and add it to the reaction solution. The solution gradually changes from light yellow to orange-yellow. Stir at room temperature for 24 hours. After completion of the reaction, transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 3500 Da and stir in deionized water for 48 hours, changing the water every 12 hours. Freeze-dry to obtain an orange, fluffy solid, MPEG-b-PLCB. 20 , yield 76% or N3-PEG-b-PLCB 20 , with a yield of 73%. The loading amount of carborane in the polymer can be further controlled by adjusting the reaction feed ratio.

[0083] Example 4

[0084] Block copolymer iRGD-PEG-b-PLCB 20 The synthesis route is as follows Figure 4 As shown, the following steps are included:

[0085] (1) Synthesis of iRGD-P

[0086] Accurately weigh 27 mg of 4-pentynoic acid, 56 mg of HOBT, and 63 mg of EDCI into a 25 mL eggplant-shaped flask. Dissolve 5 mL of DMF, then add 120 μL of DIEA and stir at room temperature for 30 minutes. Accurately weigh 100 mg of iRGD peptide and dissolve it in 1 mL of deionized water. Add this to the reactor under nitrogen protection and monitor the reaction solution in real time by high-performance liquid chromatography (HPLC) at a detection wavelength of 210 nm. After stirring at room temperature for 24 hours, the reaction is essentially complete. Transfer the mixture to a 100 mL eggplant-shaped flask and add a large amount of acetonitrile until no white flocculent precipitate forms. Centrifuge the mixture, concentrate the supernatant under reduced pressure, add acetonitrile, and repeat the above steps until no white flocculent precipitate forms. Combine the resulting solids and freeze-dry to obtain crude iRGD-P.

[0087] The crude product was dissolved in a small amount of deionized water and filtered through a 0.22 μm filter into a 5 mL EP tube. The solution was then injected into a Shimadzu LC-20A preparative liquid chromatograph using a 1 mL injector for separation. The preparative column was a Shim-pack GIST C18 (5 μm, 20 x 250 mm) column. The mobile phase consisted of acetonitrile (A) and 0.1% trifluoroacetic acid in water (B) using a gradient elution (A:B = 24:1 to 3:1) at a flow rate of 10 mL / min. The detection wavelength was 220 nm. The separated solution was concentrated under reduced pressure and freeze-dried to obtain a white, fluffy solid, iRGD-P, with a yield of 54%, which was stored at low temperatures.

[0088] (2) Block copolymer iRGD-PEG-b-PLCB 20 synthesis.

[0089] Accurately weigh N3-PEG-b-PLCB 20 50 mg of PEG-1-pyrrolidone and 23 mg of iRGD-P were placed in a 15 mL sealed tube and fully dissolved in 1 mL of DMF. 100 μL of freshly prepared CuI catalyst solution (accurately weigh 10 mg of CuI in a 2 mL EP tube, add 1 mL of DMF and 17 μL of DIEA, and mix by ultrasonic vibration) was added to the reaction solution and stirred at room temperature for 24 hours. After the reaction, the reaction solution was transferred to a dialysis bag with a molecular weight cutoff of 3500 Da and stirred in deionized water for 48 hours, changing the water every 12 hours. The solution was freeze-dried to obtain an orange fluffy solid, i.e., iRGD-PEG-b-PLCB. 20 , yield 80%, stored at low temperature.

[0090] Example 5

[0091] Block copolymer IP-PEG-b-PLCB 20 The synthesis route is as follows Figure 5 As shown, the following steps are included:

[0092] (1) Synthesis of IP-P

[0093] Accurately weigh 500mg of IP, 350mg of HOBT, and 495mg of EDCI into a 100mL eggplant-shaped flask. Dissolve thoroughly in 20mL of DMF, then add 761μL of DIEA and stir at room temperature for 30 minutes. Add 165μL of propargylamine to the reaction mixture and stir at room temperature for 12 hours. After the reaction, spin dry the solvent, add 20mL of deionized water, extract three times with DCM, dry over anhydrous sodium sulfate, and separate by column chromatography (gradient elution with DCM:MeOH = 200:1 to DCM:MeOH = 100:1) to obtain a white solid, IP-P, in a 95% yield. Store at low temperature.

[0094] (2) Block copolymer IP-PEG-b-PLCB 20 Synthesis

[0095] Accurately weigh N3-PEG-b-PLCB 20 50mg of PEG-β-P and 7mg of IP-P were placed in a 15mL sealed tube and fully dissolved in 1mL of DMF. 100μL of freshly prepared CuI catalyst solution (accurately weigh 10mg of CuI in a 2mL EP tube, add 1mL of DMF and 17μL of DIEA, and mix thoroughly with ultrasonic vibration) was added to the reaction solution and stirred at room temperature for 24h. After the reaction, the reaction solution was transferred to a dialysis bag with a molecular weight cutoff of 3500Da and stirred in deionized water for 48h. The water was changed every 12h and freeze-dried to obtain an orange fluffy solid, namely IP-PEG-b-PLCB. 20 , yield 67%, stored at low temperature.

[0096] Example 6

[0097] Block copolymer CHPpa-PEG-b-PLCB 20 The synthesis route is as follows Figure 6 As shown, the following steps are included:

[0098] (1) Synthesis of CHPpa-P

[0099] Accurately weigh 80 mg of CHPpa, 30 mg of HOBT, and 42 mg of EDCI into a 25 mL eggplant-shaped flask. Dissolve thoroughly in 4 mL of DMF, then add 64 μL of DIEA and stir at room temperature for 30 min. Add 12 μL of propargylamine to the reaction mixture and stir at room temperature for 12 h. After the reaction, spin dry the solvent, add 5 mL of deionized water, extract three times with DCM, dry over anhydrous sodium sulfate, and separate by column chromatography (gradient elution with DCM:MeOH = 200:1 to DCM:MeOH = 20:1) to obtain a dark green solid, CHPpa-P, in an 80% yield. Store at low temperature.

[0100] (2) Block copolymer CHPpa-PEG-b-PLCB 20 Synthesis

[0101] Accurately weigh N3-PEG-b-PLCB 2050mg of PEG-1-hydroxy-1-pyrrolidone and 12mg of CHPpa-P were placed in a 15mL sealed tube and fully dissolved in 1mL of DMF. 100μL of freshly prepared CuI catalyst solution (accurately weigh 10mg of CuI in a 2mL EP tube, add 1mL of DMF and 17μL of DIEA, and mix thoroughly with ultrasonic vibration) was added to the reaction solution and stirred at room temperature for 24h. After the reaction, the reaction solution was transferred to a dialysis bag with a molecular weight cutoff of 3500Da and stirred in deionized water for 48h. The water was changed every 12h and freeze-dried to obtain a dark green fluffy solid, namely CHPpa-PEG-b-PLCB. 20 , yield 67%, stored at low temperature.

[0102] Example 7

[0103] The series of compounds in Examples 1-6 were characterized, MPEG-b-PLL-Cbz, MPEG-b-PLCB 20 、iRGD-PEG-b-PLCB 20 、IP-PEG-b-PLCB 20 and CHPpa-PEG-b-PLCB 20 of 1 The H NMR and IR characterization results are shown in Figure 7 、 Figure 8 As shown, the successful synthesis of the compound was confirmed.

[0104] Example 8

[0105] Preparation and stability testing of tumor-targeting boron-rich peptide micelles

[0106] iRGD-PEG-PLCB 20 The preparation of boron-rich peptide micelles is taken as an example. Accurately weigh MPEG-b-PLCB 20 57 mg, 54 mg, 48 mg and 42 mg were placed in 5 mL EP tubes, and iRGD-b-PEG-PLCB was added to each 20 3mg, 6mg, 12mg and 18mg were dissolved in 2mL DMF, respectively. Then, each was transferred to a dialysis bag with a molecular weight cutoff of 1000Da, stirred at 200rpm in a beaker containing 1L PBS for 12h, and filtered through a sterile filter membrane (220nm) in a biosafety cabinet to obtain four tumor-targeting boron-rich polypeptide micelles iRGD-PEG-PLCB with different degrees of modification of the targeting molecule (5%, 10%, 20% and 30%). 20 IP-PEG-PLCB 20 and CHPpa-PEG-PLCB 20 The preparation method of is similar and all are stored at 4°C.

[0107] iRGD-PEG-PLCB with different targeting molecule modification degrees (5%, 10%, 20% and 30%) were respectively added to the 20 、IP-PEG-PLCB 20 and CHPpa-PEG-PLCB 20 The three targeted micelles were divided into seven equal parts and stored in a refrigerator at 4°C. One part was taken every day to measure the changes in the hydrated particle size and polydispersity index (PDI).

[0108] The experimental results are as follows Figure 9 As shown in the figure, the change of modification degree did not significantly affect the hydrated particle size of the micelles. 20 、IP-PEG-PLCB 20 and CHPpa-PEG-PLCB 20 The particle size of the three targeted peptide micelles did not change significantly at different modification degrees, and the uniformity was good. No significant mutations caused by micelle disintegration occurred, demonstrating the excellent stability of boron-rich peptide micelles in vitro.

[0109] Example 9

[0110] In vitro cell experiments on tumor-targeting boron-rich peptide micelles

[0111] (1) MTT method to evaluate the in vitro cytotoxicity of tumor-targeted boron-rich peptide micelles

[0112] The density of the logarithmic growth phase is 3×10 4 A mouse oral squamous cell carcinoma cell line (MOC-1) cell suspension at a concentration of 1000 cells / mL was added to a 96-well plate, with 8,000 cells seeded per well. The cells were cultured at 37°C and 5% CO2 for 12 h. The freshly prepared iRGD-PEG-PLCB was determined by inductively coupled plasma chromatograph (ICP-OES). 20 After the cells attached, the micelle PBS solution was added to DMEM complete medium (10% FBS, 1% P / S) to prepare a drug solution with a boron concentration gradient of 0.16mM, 0.32mM, 0.63mM, 1.3mM, 2.5mM, and 5mM. The original culture medium in the 96-well plate was discarded, and 100μL of drug-containing medium was added to each well (n=4). After incubation with MOC-1 cells for 12 hours, 10μL of 5mg / mL MTT solution was added to each well under dark conditions and incubated for another 4 hours. After the end, the solution in the 96-well plate was discarded, and the bottom of the plate was rinsed with pre-cooled PBS. After three times, 150μL of chromatography-grade DMSO was added to each well. The plate was shaken for 5 minutes using a multi-function microplate reader, and the absorbance (OD) of each well was measured at a wavelength of 570nm. The experiment was repeated three times, and 100μL of drug-free medium was added to the control group. The cell survival rate was calculated according to the following formula:

[0113] Cell survival rate (%) = (OD of experimental group / OD of control group) × 100%

[0114] Similarly, IP-PEG-PLCB was determined 20 and CHPpa-PEG-PLCB 20 The experimental results are as follows Figure 10 As shown, iRGD-PEG-PLCB with different gradient modification degrees 20 、IP-PEG-PLCB 20 and CHPpa-PEG-PLCB 20 When the boron concentration was as high as 5 mM, there was no obvious cytotoxicity and the survival rate of the MOC-1 cell line was as high as over 75%.

[0115] (2) Screening of the optimal modification degree of tumor-targeting boron-rich peptide micelles

[0116] MOC-1 cell suspension (1×10 6 10 cells / mL) were inoculated into 6-well plates, and 10 cells / mL were inoculated into each well. 6 Cells were cultured at 37°C and 5% CO2 for 12 hours. After the cells attached, the culture medium in the well plate was aspirated, washed with PBS, and iRGD-PEG-PLCB with different targeting molecule modification degrees (5%, 10%, 20% and 30%) with a boron concentration of 1.2 mM was added. 20 、IP-PEG-PLCB 20 and CHPpa-PEG-PLCB 20 1 mL of culture medium solution was incubated for 2 h (n = 6). After the incubation, the culture medium was aspirated and the bottom of the plate was rinsed three times with PBS. 1 mL of digestion solution (concentrated sulfuric acid: concentrated nitric acid = 1:1) was added to each well and digested at room temperature for 48 h. The samples were transferred to 5 mL EP tubes, fixed to 3 mL with deionized water, and filtered through a 220 nm filter membrane. The boron content in the samples was determined by ICP-OES. The boron concentration of the standard was 0.04 mg / L, 0.08 mg / L, and 0.16 mg / L. R 2 >0.999, and the cellular boron uptake was calculated according to the following formula:

[0117] Boron content of sample = ICP measured boron concentration × sample volume

[0118] Boron intake of experimental group samples = boron content of experimental group samples - boron content of blank group samples

[0119] The experimental results are as follows Figure 11 As shown, the optimal modification degree of each targeted micelle is different, iRGD-PEG-PLCB 20 、IP-PEG-PLCB20 and CHPpa-PEG-PLCB 20 The modification degrees were 20%, 5% and 10% respectively, and subsequent experiments were carried out with the optimal modification degree of each micelle.

[0120] (3) Quantitative analysis of in vitro cellular uptake of tumor-targeting boron-rich peptide micelles

[0121] MOC-1 cell suspension (1×10 6 10 cells / mL) were inoculated into 6-well plates, and 10 cells / mL were inoculated into each well. 6 Cells were cultured at 37°C and 5% CO2 for 12 hours. After the cells adhered, the culture medium in the well plate was aspirated, washed with PBS, and 1 mL of culture medium solution with a boron concentration of 1.2 mM disodium thiododecaborane (BSH) and 4-boron-L-phenylalanine fructose complex (BPA-f) (control) and iRGD-PEG-PLCB with the best targeting molecule modification were added. 20 (20%), IP-PEG-PLCB 20 (5%) and CHPpa-PEG-PLCB 20 1 mL of (10%) culture medium solution was added and incubated for 0.5 h, 1 h, 2 h, 4 h, 8 h and 12 h. The post-processing steps were the same as the MTT method in (1).

[0122] The experimental results are as follows Figure 12 As shown in the results, at any time point, the boron uptake efficiency of boron-rich peptide micelles in cells was significantly better than that of the control drugs BSH and BPA-f; comparative experiments further showed that the boron uptake of tumor-targeted boron-rich peptide micelles at the optimal modification degree was higher than that of non-tumor-targeted boron-rich peptide micelles MPEG-PLCB. 20 There was a significant improvement, and the results confirmed that targeting molecules can significantly improve the efficiency of boron delivery at the cellular level.

[0123] (4) Qualitative analysis of in vitro cellular uptake of tumor-targeted boron-rich peptide micelles

[0124] Non-targeted boron-rich peptide micelles MPEG-PLL-PLCB 20 Take CHPpa as an example. Accurately weigh MPEG-b-PLCB 20 60 mg of PEG-10 and 1 mg of CHPpa were placed in a 5 mL EP tube, and 2 mL of DMF was added. After sonication, the mixture was transferred to a dialysis bag with a molecular weight cutoff of 1000 Da. The mixture was dialyzed at 200 rpm in a beaker containing 1 L of PBS for 12 h. The mixture was filtered through a sterile filter membrane (220 nm) in a biosafety cabinet to obtain MPEG-PLL-PLCB. 20 @CHPpa, except CHPpa-PEG-PLCB 20 In addition, iRGD-PEG-PLCB20 @CHPpa and IP-PEG-PLCB 20 @CHPpa was prepared in the same way and stored at 4°C.

[0125] MOC-1 cell suspension (1×10 6 cells / mL) were inoculated into 12-well plates, and 5×10 5 The cells were cultured at 37°C and 5% CO2 for 12 h. After the cells attached to the wall, the culture medium was discarded and 500 μL of CHPpa-PEG-PLCB was added to each well. 20 、MPEG-PLCB 20 @CHPpa、iRGD-PEG-PLCB 20 @CHPpa and IP-PEG-PLCB 20 @CHPpa culture medium solution, wherein the fluorescence intensity of the above micelles was consistent, the CHPpa dosage concentration was 4.1 μg / mL, and the incubation period was 0.5h, 1h, 2h, 4h, 8h, and 12h (n=3). After the incubation period, the culture medium was aspirated and discarded, the plate bottom was rinsed three times with PBS, and the cells were fixed with 20 μL of 4% paraformaldehyde solution for 10 min. The cell nuclei were stained with DAPI for 20 minutes, and the red fluorescence characteristic of the drug was used to detect the red fluorescence APC channel (red fluorescence, excitation wavelength λ ex =633nm, fluorescence intensity signal collection λ em =660nm), cell nuclei were labeled with DAPI (blue fluorescence, excitation wavelength λ ex =375nm, fluorescence intensity signal collection λ em =440-480 nm), and fluorescence images of the cells were collected using a fluorescence microscope.

[0126] The experimental results are as follows Figure 13 As shown in the figure, the intracellular fluorescence intensity of the four micelles showed an increasing trend with the extension of incubation time, which was consistent with the results of ICP-OES determination of boron accumulation, confirming that the uptake of boron-rich peptide micelles by MOC-1 cell line was time-dependent and the introduction of targeting molecules achieved the enhancement of the boron uptake ability of tumor cells.

[0127] Example 10

[0128] In vivo biodistribution of tumor-targeting boron-rich peptide micelles

[0129] MOC-1 cells in good growth condition were digested with 0.25% trypsin and centrifuged to remove the supernatant. Resuspended in 5 mL PBS and centrifuged, the supernatant was discarded, and repeated three times. The cells were counted and the suspension density was adjusted to 1×10 7cells / mL, transferred to a 5mL EP tube. 7-8 week old C57BL / 6j male black mice were selected, and after one week of culture, 2.5% afodine (200mg / kg) was injected intraperitoneally to anesthetize the mice. Use iodine tincture to wipe the surgical site, use tweezers to carefully pinch the skin 1.5cm below the eye on the right cheek of the mouse, mix the cell suspension in the EP tube, use a sterile 1mL syringe to draw 25μL, and slowly inject the cell suspension into the mouse cheek. Leave the needle in place for 1min until the tumor cells have fully infiltrated, then slowly withdraw the needle. Use iodine tincture to disinfect the tumor wound site of the mouse and raise it under normal conditions. Observe the survival status of the mouse. 7 days after the tumor is implanted, the right cheek of the mouse can be seen to be significantly bulging, indicating that the in situ oral squamous cell carcinoma model in mice has been successfully established.

[0130] Thirty-six mice bearing tumors that had successfully established an in situ oral squamous cell carcinoma model were randomly divided into nine groups, with four mice in each group. One group received a tail vein injection of 200 μL PBS as a blank group, while the other three groups received a tail vein injection of MPEG-PLCB at a dose of 2.5 mg B / kg. 20 、iRGD-PEG-PLCB 20 、IP-PEG-PLCB 20 and CHPpa-PEG-PLCB 20 , the mice were killed 12h and 24h after administration, and the hearts, spleens, lungs, kidneys, brains, tumor tissues, paracancerous tissues, livers and blood of the mice were dissected and removed. After the organs and tissues were removed, they were rinsed with PBS and all samples were transferred to centrifuge tubes and weighed. The digestion solution (concentrated sulfuric acid: concentrated nitric acid = 1:1) was prepared, and 3mL was added to the centrifuge tubes containing the heart, spleen, lungs, kidneys and brain, 1mL was added to the tumor tissue and paracancerous tissue, and 7mL was added to the liver and blood. The digestion was carried out at room temperature for 48h. The digestion was completed when each sample turned light yellow, clear and transparent. The above sample groups were diluted to 6mL, 2mL and 20mL respectively with deionized water, filtered with a 220nm filter membrane, and the boron content in the samples was determined by ICP-OES. The boron concentration of the standard was configured to be 0.04mg / L, 0.08mg / L and 0.16mg / L, R 2 >0.999, and calculate the boron content of the sample according to the following formula:

[0131] Sample boron content = (measured boron concentration × sample volume) / tissue mass

[0132] Boron intake of experimental group samples = boron content of experimental group samples - boron content of blank group samples

[0133] The experimental results are as follows Figure 14 、 Figure 15 As shown, both the amount of boron accumulation in the tumor area and the specific boron accumulation in the tumor area are significantly different from those of the non-tumor-targeted boron-rich peptide micelle MPEG-PLCB. 20, iRGD-PEG-PLCB 20 Both showed significant advantages, further indicating that the introduction of targeting molecules can significantly enhance the specific enrichment of boron in tumor tissues.

Claims

1. A tumor-targeting boron-rich peptide carrier material, characterized in that: Its structural formula is as follows: Where R1 is R2 is a carboxylated carborane molecule, z is an integer from 0 to 10; R3 is the targeting molecule; x is a positive integer from 45 to 150; y is a positive integer ranging from 5 to 35.

2. The tumor-targeting boron-rich peptide carrier material according to claim 1, characterized in that: z is an integer from 2 to 6, x is a positive integer from 100 to 120, and y is a positive integer from 15 to 25; R3 is a targeting molecule including iRGD, cRGD, Angiopep-2, folic acid, iodophenylbutyric acid and pyropheophorbide a; and R2 is 3-(1,2-dicarbonadecaborane)propionic acid.

3. The method for preparing the tumor-targeting boron-rich polypeptide carrier material according to claim 1 or 2, characterized in that: The steps include: (1) Synthesis of N6-Lys-NCA: N6-Lys-Cbz was added to a mixed solvent of anhydrous tetrahydrofuran and propylene oxide, stirred evenly, and triphosgene was added. The mixture was stirred at 40-70°C under inert gas protection until the reaction was complete to obtain N6-Lys-NCA. (2) Synthesis of block copolymer PEG-b-PLL: PEG-NH2 was dissolved in a NaHCO3 solution at pH 8-9, and N6-Lys NCA obtained in step (1) was added. The mixture was stirred in an ice bath for 0.5-2 h, and then vigorously stirred at room temperature for 20-48 h to obtain PEG-b-PLL-Cbz. PEG-b-PLL-Cbz was dissolved in trifluoroacetic acid, and an acetic acid solution containing 30-40% by volume of hydrobromic acid was added. The mixture was stirred in an ice bath for 1-3 h, dialyzed, and lyophilized to obtain a PEG-b-PLL solid powder. (3) Synthesis of block copolymer PEG-b-PLCB: Carboxylated carborane molecules, 1-hydroxybenzotriazole, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N,N-diisopropylethylamine were added to an eggplant-shaped flask, and an organic solvent was added. After stirring for 20 to 60 minutes, the PEG-b-PLL obtained in step (2) was added, and the mixture was stirred at room temperature for 20 to 48 hours. The mixture was dialyzed and freeze-dried to obtain a PEG-b-PLCB solid powder. (4) The targeting molecule connected with an alkynyl group and the PEG-b-PLCB obtained in step (3) were added to DMF to dissolve, and a catalyst solution containing CuI was added. The mixture was stirred at room temperature for more than 24 hours, and freeze-dried to obtain a tumor-targeted boron-rich polypeptide carrier material.

4. The preparation method according to claim 3, characterized in that The molar ratio of N6-Lys-Cbz, triphosgene and propylene oxide described in step (1) is 1:(0.2-0.7):(5-10); the volume ratio of anhydrous tetrahydrofuran and propylene oxide is (20-5):1; the reaction temperature is 40-60°C, and the reaction time is 1-4h.

5. The preparation method according to claim 3, characterized in that The PEG-NH2 described in step (2) includes MPEG-NH2 or N3-PEG-NH2, and the molecular weight of PEG is 200-20000; the molar ratio of the N6-Lys NCA to PEG-NH2 is (5-25):1; and the molar ratio of PEG-b-PLL-Cbz to hydrobromic acid is 1:(1-1.5).

6. The preparation method according to claim 3, characterized in that The organic solvent described in step (3) includes N,N-dimethylformamide and N,N-dimethylacetamide; the molar ratio of the carboxylated carborane molecule, HOBT, EDCI, DIEA and PEG-b-PLL is (5-25):(6-30):(6-30):(12.5-62.5):

1.

7. The preparation method according to claim 3, characterized in that The preparation process of the CuI catalyst solution described in step (4) is as follows: accurately weigh 10 mg of CuI into a 2 mL EP tube, add 1 mL of DMF and 17 μL of DIEA, and mix by ultrasonic vibration.

8. A method for preparing tumor-targeted boron-rich polypeptide micelles, comprising dissolving the tumor-targeted boron-rich polypeptide carrier material according to claim 1 or 2 or the tumor-targeted boron-rich polypeptide carrier material obtained by the preparation method according to any one of claims 3 to 7 in solvent A, transferring the dissolved material to a dialysis bag with a molecular weight cutoff of 500 to 5000 Da, and dialyzing the mixture in solvent B at a stirring speed of 50 to 400 rpm for 12 to 24 hours to obtain tumor-targeted boron-rich polypeptide micelles. The solvent A is dimethyl sulfoxide, N,N-dimethylformamide or N-methylpyrrolidone; the solvent B is water or phosphate buffer.

9. The tumor-targeting boron-rich polypeptide micelles obtained by the preparation method according to claim 8.

10. Use of the tumor-targeting boron-rich peptide micelles according to claim 9 in the preparation of anti-tumor drugs.

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