Blood vessel blocking agent and preparation method and application thereof

Abstract

The invention provides a blood vessel blocking agent as shown in a formula (I). The polymer vascular blocker provided by the invention can reside and accumulate at a tumor site for a long time, and the release of effective drugs is promoted. The medicine can destroy ester bonds through tumor lactonase to quickly release CA4, destroy tumor blood vessels, improve the tumor hypoxia level, promote the release of hypoxia-sensitive AVE8063, further destroy the tumor blood vessels and improve the tumor inhibition effect.

Description

Technical Field

[0001] The present invention relates to the field of medical technology, and in particular to a blood vessel blocking agent, a preparation method and application thereof. Background Art

[0002] Cancer has become the leading cause of death and serious threat to human health. Vascular depletion therapy, a relatively new treatment modality, aims to irreversibly destroy established tumor vasculature by inducing endothelial cell apoptosis, thereby cutting off nutrient supply and metastatic pathways, leading to tumor necrosis and metastasis inhibition. In 1994, the US Food and Drug Administration (FDA) mandated that vascular depletion therapy be used clinically as a complementary approach alongside other treatment modalities to prevent tumor recurrence and metastasis. Vascular depletion agents (VDAs) can disrupt immature tumor vasculature, leading to necrosis within the tumor, achieving long-term, localized effects rather than disseminating throughout the tumor mass to achieve their effectiveness. The tumor vasculature ensures the supply of oxygen, energy, and nutrients to the tumor, enabling tumor growth and expansion, followed by invasion and metastasis. VDAs rapidly shut down tumor blood vessels, depriving them of the necessary supplies for tumor growth, resulting in increased vascular permeability and extensive ischemic necrosis, ultimately inhibiting tumor growth. However, to date, most VDAs have not been successful in clinical trials, primarily due to off-target effects that can lead to serious toxicities, such as cardiotoxicity, and dose-limiting toxicities that make it difficult to achieve the desired therapeutic effect. Combretastatin (combretastatin, (Z)-3,4,5,4'-tetramethoxy-3'-hydroxystilbene, Combretastatin A4, CA4) and AVE8063 ((Z)-3,4,5,4'-tetramethoxy-3'-aminostilbene) are recently developed novel anti-tumor compounds with the following structural formulas:

[0003]

[0004] Unlike traditional cytotoxic anticancer drugs, CA4 does not directly kill tumor cells. CA4 and AVE8063 employ a novel anticancer mechanism: by binding to the microtubules in the tumor's vascular endothelial cells, they destroy blood vessels within the tumor, cutting off the tumor's blood and nutrient supply and inducing severe necrosis within the tumor. Due to the structural differences between tumor blood vessels and those in normal tissue, CA4 and AVE8063 selectively destroy tumor blood vessels while having little effect on the blood supply to normal tissue. Therefore, this class of drugs holds high hopes in the anticancer field.

[0005] Because CA4 has poor water solubility and is difficult to administer directly intravenously, Tang Zhaohui and his colleagues designed and synthesized a polymer-bound drug to bind to CA4. This drug can accumulate in tumor blood vessels and slowly release the active drug, thereby exerting a long-term effect of destroying tumor blood vessels at the tumor site. However, the stability of the CA4 bond in this polymer-bound drug is insufficient. While this drug can mitigate the toxicity of small-molecule CA4 to some extent, it still cannot effectively address the problem of systemic toxicity. Therefore, the development of a vascular occluding anti-tumor drug that can be selectively released at the tumor site is a current problem that needs to be solved.

[0006] Existing approaches to reduce the toxic side effects of vascular occluders include: 1) designing bioreductive prodrugs of VDAs. Based on the differences in enzyme levels between tumor and normal tissues, tumor microenvironment-sensitive antitumor prodrugs are constructed to achieve selective activation of VDAs at the tumor site; and 2) designing VDA nanomedicines to achieve VDA enrichment at the tumor site. Atkinson et al., leveraging the high expression of matrix metalloproteinase 14 (MMP-14) in tumors, developed a peptide-conjugated prodrug, ICT2588, from azademethylcolchicine and explored its therapeutic efficacy against various solid tumors and its cardiovascular side effects. Thomson et al. developed bioreductively activated VDA prodrug conjugates. After chemically linking protective groups, these VDA prodrugs are relatively stable in phosphate buffer, but undergo enzyme-mediated hydrolysis in the hypoxic environment of the tumor, resulting in selective tumor activation. Combretastatin disodium phosphate (CA4P) is a phosphate prodrug of CA4. It binds to tubulin and selectively destroys primary tumor blood vessels, rapidly severing the tumor's blood supply and leading to necrosis in the central region of the tumor. CA4P has completed multiple clinical trials, including those investigating CA4P alone and in combination with chemotherapy, radiotherapy, and angiogenesis inhibitors. Oribulin (AVE8062) belongs to the combretastatin family of angiostatic agents. After administration, oribulin releases its active metabolite, AVE8063, in vivo. Based on the differences in enzymes, pH, glutathione, reactive oxygen species, and oxygen partial pressure (hypoxia) between tumor and normal tissue, a tumor-microenvironment-sensitive, tumor-selective angiostatic prodrug has been developed. This holds promise for achieving selective activation at the tumor site and exerting its angiostatic effect. Because tumor tissues are often not sufficiently differentiated from normal tissues, tumor-selective activation of angiostatic prodrugs that are sensitive to the tumor microenvironment lacks tumor selectivity. To date, most clinical trials of VDAs have been unsuccessful, mainly due to off-target effects of the drugs that bring about serious toxic effects, such as cardiotoxicity. At the same time, dose-limiting toxicity makes it difficult to achieve the expected therapeutic effect.

[0007] Therefore, obtaining angiostatic antitumor drugs that can be efficiently and selectively released at the tumor site is a problem that needs to be solved at present. Summary of the Invention

[0008] In view of this, the technical problem to be solved by the present invention is to provide a vascular blocking agent, which can be efficiently and selectively released at the tumor site.

[0009] The drug provided by the present invention will rely on its own action to expand the difference between tumors and normal tissues, and achieve efficient and selective release of the drug at the tumor site.

[0010] Vascular blocker (VDAs) nanodrugs are distributed around tumor blood vessels due to their low penetration into solid tumor tissues. The released drugs can selectively destroy immature tumor blood vessels, block the supply of oxygen and nutrients, and cause necrosis inside the tumor. VDAs can also increase the vascular permeability of tumors, further increase the extravasation of VDAs nanodrugs at the tumor site, significantly reduce the dependence of nanodrugs on tumor blood vessels, enhance permeability and retention effects, and improve the efficacy of vascular blockers. The technical problem to be solved by the present invention is to provide a polymer vascular blocker drug and a preparation method thereof. The polymer vascular blocker provided by the present invention can reside and accumulate at the tumor site for a long time and promote the release of effective drugs. The drug can initially quickly release CA4 by destroying the ester bond through intratumoral esterases, destroy tumor blood vessels, increase the level of tumor hypoxia, promote the release of hypoxia-sensitive AVE8063, further destroy tumor blood vessels, and improve the tumor inhibition effect.

[0011] The present invention provides a vascular blocking agent represented by formula (I),

[0012]

[0013] Wherein, R1 is selected from a C2-C10 straight-chain alkyl group, a C3-C10 branched-chain alkyl group, or a C6-C20 aryl group; preferably, R1 is a C3-C8 straight-chain alkyl group, a C5-C8 branched-chain alkyl group, or a C8-C15 aryl group;

[0014] Among them, the straight-chain alkyl groups of C2-C10 include ethyl (-C2H5), n-propyl (-C3H7), n-butyl (-C4H9), n-pentyl (-C5H 11 ), n-hexyl (-C6H 13 ), n-heptyl (-C7H 15 ), n-octyl (-C8H 17 ), n-nonyl (-C9H 19 ), n-decyl (-C 10 H 21), their carbon atoms are connected in a straight line. C3-C10 branched alkyl, such as isopropyl, isobutyl, sec-butyl, tert-butyl, etc., has a branched carbon atom chain in its structure. And C6-C20 aryl, such as phenyl (-C6H5), naphthyl (-C 10 H7) etc.

[0015] R2 is selected from H, C2-C10 straight chain alkyl, C3-C10 branched chain alkyl or C6-C20 aryl; preferably, R2 is C3-C8 straight chain alkyl, C5-C8 branched chain alkyl or C8-C15 aryl;

[0016] Among them, the straight-chain alkyl groups of C2-C10 include ethyl (-C2H5), n-propyl (-C3H7), n-butyl (-C4H9), n-pentyl (-C5H 11 ), n-hexyl (-C6H 13 ), n-heptyl (-C7H 15 ), n-octyl (-C8H 17 ), n-nonyl (-C9H 19 ), n-decyl (-C 10 H 21 ), their carbon atoms are connected in a straight line. C3-C10 branched alkyl, such as isopropyl, isobutyl, sec-butyl, tert-butyl, etc., has a branched carbon atom chain in its structure. And C6-C20 aryl, such as phenyl (-C6H5), naphthyl (-C 10 H7) etc.

[0017] R3 is selected from H or a cation; R3 is selected from a hydrogen atom, a metal cation or an organic cation.

[0018] The metal cation is selected from sodium ion and potassium ion; the organic cation is selected from ammonium ion or positively charged amino acid ion.

[0019] R4 is selected from unsubstituted C1-C20 alkyl or substituted C1-C20 alkyl; R4 is selected from unsubstituted C2-C20 straight-chain alkyl, unsubstituted C3-C20 branched alkyl, substituted C2-C20 straight-chain alkyl or substituted C3-C20 branched-chain alkyl. The substituent in the substituted C2-C20 straight-chain alkyl is one or more of hydroxyl, aldehyde, amino, sulfhydryl and sugar residue; the substituent in the substituted C3-C20 branched-chain alkyl is one or more of hydroxyl, aldehyde, amino, sulfhydryl and sugar residue;

[0020] R5 is selected from a hydrogen atom or a C1-C6 alkyl acyl group; preferably, R5 is selected from a hydrogen atom, an acetyl group or a propionyl group.

[0021] L1, L2, L3, L4 are independently selected from -CH2- or -CH2CH2-;

[0022] L5 is selected from C2-C10 straight chain alkyl; C2-C10 straight chain alkyl includes ethyl (-C2H5), n-propyl (-C3H7), n-butyl (-C4H9), n-pentyl (-C5H 11 ), n-hexyl (-C6H 13 ), n-heptyl (-C7H 15 ), n-octyl (-C8H 17 ), n-nonyl (-C9H 19 ), n-decyl (-C 10 H 21 ).

[0023] E1 is selected from an amide bond or an ester bond;

[0024] Z1 is selected from nitrogen (N), carbon (C) or oxygen (O);

[0025] v, x, y, z are the percentages of the group, v+x+y+z=1, v>0, x>0, y>0, z>0; n is the degree of polymerization, 10≤n≤500; n can be 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 90, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500.

[0026] The present invention provides a method for preparing the vascular blocking agent described in the above technical solution, comprising the following steps:

[0027] The compound of formula (II) and methoxypolyethylene glycol are dissolved in a solvent, triethylamine, 4-dimethylaminopyridine, 4-dimethylaminopyridine and Azo-8063 of formula (III) are added for reaction, and then CA4 is added to continue the reaction. After the reaction is completed, the mixture is precipitated with a solvent, redissolved, dialyzed and then freeze-dried to obtain the product.

[0028]

[0029]

[0030] The synthetic route of the present invention is preferably as follows:

[0031]

[0032] The present invention first prepares Azo-8063 of formula (III). The present invention preferably prepares it according to the following reaction route:

[0033]

[0034] In one embodiment, it is preferably:

[0035] First, compound AVE8063 was dissolved in acetone, water was added, and hydrochloric acid solution (2 M) was added under ice bath conditions;

[0036] The concentration of AVE8063 in acetone was 0.1 M.

[0037] The ice bath condition is preferably 0 to 5°C.

[0038] The concentration of compound AVE8063 and hydrochloric acid solution is 1:2 to 1:3

[0039] Then weigh sodium nitrite and dissolve it in water, add it dropwise into the reaction system, and react in an ice bath for 20 to 30 minutes. Use sodium hydroxide solution (1M) to adjust the solution pH to 6 to 7.

[0040] The molar ratio of compound AVE8063 to sodium nitrite is 1:1. Add slowly.

[0041] Weigh N-methyl-N-hydroxyethylaniline, dissolve it in acetone, and add it to the reaction system. After reacting at room temperature for 2-3 hours, add dichloromethane, wash with water 2-3 times, then with saturated brine 2-3 times. Dry the organic layer over anhydrous sodium sulfate overnight and separate it through a column to obtain the product Azo-8063.

[0042] The mass ratio of compound AVE8063 and N-methyl-N-hydroxyethylaniline is 2:1 to 1:1

[0043] The compound of formula (II) and methoxypolyethylene glycol are dissolved in a solvent.

[0044] The preparation method of PLG of the present invention comprises:

[0045] Dissolve γ-benzyl-L-glutamate-N-carboxylic anhydride monomer (BLG-NCA) in ultra-dry N,N-dimethylformamide (DMF), stir to dissolve, then add 1.0 mL of n-hexylamine (n-HA) (concentration: 1 mM, solvent: DMF), seal the container, and stir the reaction at 25°C for 60 to 72 hours.

[0046] The concentration of the γ-benzyl-L-glutamate-N-internal carboxylic anhydride monomer in DMF is 0.1 g / mL to 1 g / mL, preferably 0.1 g / mL to 0.5 g / mL, and more preferably 0.15 g / mL.

[0047] The mass ratio of the γ-benzyl-L-glutamate-N-internal carboxylic acid anhydride monomer to n-hexylamine is 160:1 to 500:1, preferably 160:1 to 240:1, and more preferably 160:1.

[0048] Afterwards, acetic anhydride was added to the above reaction system and the reaction was continued for 5 to 6 hours.

[0049] The mass ratio of γ-benzyl-L-glutamate-N-internal carboxylic acid anhydride monomer, n-hexylamine, and acetic anhydride is 160:1:20 to 500:1:20, preferably 160:1:20 to 240:1:20, and more preferably 160:1:20.

[0050] After the reaction is completed, the obtained reaction solution is precipitated into diethyl ether, filtered and washed with diethyl ether in sequence, and dried in vacuum at room temperature for 20 to 24 hours to obtain the intermediate product poly(γ-benzyl-L-glutamate) (PBLG).

[0051] The prepared poly(γ-benzyl-L-glutamate) was dissolved in dichloroacetic acid, and a 33% by weight hydrogen bromide / glacial acetic acid solution was added under stirring, and the mixture was stirred at 30° C. for 1 hour.

[0052] The mass ratio of poly(γ-benzyl-L-glutamate) in hydrogen bromide / glacial acetic acid is 1:2 to 1:5, preferably 1:3;

[0053] Afterwards, the obtained reaction solution was precipitated in diethyl ether and centrifuged. The obtained precipitate was redissolved with DMF, dialyzed with deionized water, and freeze-dried to obtain an acetyl-terminated poly(L-glutamic acid) polymer (PLG).

[0054] The parameters of the dialysis and freeze-drying of the present invention are that the molecular weight of the dialysis bag is greater than 500 Da, and the temperature of the freeze-drying constant temperature section is 25-60° C.

[0055] The compound of formula (II) and methoxy polyethylene glycol are dissolved in a solvent; the solvent is ultra-dry DMF.

[0056] The mass ratio of the compound of formula (II) to methoxy polyethylene glycol is 1:2 to 1:3

[0057] Then triethylamine (TEA) and 4-dimethylaminopyridine (DMAP) were weighed, dissolved in ultra-dry DMF, and added to the reaction system.

[0058] The mass ratio of triethylamine (TEA) and 4-dimethylaminopyridine (DMAP) is 1:1

[0059] Then, 2,4,6-trichlorobenzoyl chloride (TBC) is slowly added to the reaction system, followed by Azo-8063 dissolved in ultra-dry DMF and added to the reaction system. The temperature is maintained at 20-60°C, preferably 20-30°C, and the reaction is carried out for 1-6 hours, specifically 1, 2, 3, 4, 5, or 6 hours.

[0060] The mass ratio of 2,4,6-trichlorobenzoyl chloride (TBC) and Azo-8063 is 1:1

[0061] The concentration of Azo-8063 dissolved in ultra-dry DMF is 0.1g / mL to 1g / mL

[0062] CA4 was then added to the reaction system, TBC was added, and the reaction was continued for 2 hours. After the reaction was completed, the solution was precipitated with anhydrous ether, redissolved, dialyzed once with water, and then freeze-dried to obtain the nanoparticle CA4 / Azo-8063 loaded with CA4 and Azo-8063.

[0063] The co-loading ratio of CA4 and Azo-8063 of the present invention can be selected from 1:2 to 1:8; specifically, it can be 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, or 1:8.

[0064] The present inventors have found that the tumor inhibition effect is significantly improved after Azo-8063 and CA4 are co-loaded. When the ratio of CA4 to Azo-8063 is 1:4, the tumor inhibition effect is optimal.

[0065] The present invention provides use of any one of the above-mentioned vascular blocking agents in the preparation of a drug for treating cancer.

[0066] The prevention and treatment of the present invention includes: causing tumor cell necrosis, inhibiting tumor growth and destroying tumor blood vessels or several of them.

[0067] The cancers described in the present invention include one or more of nasal and paranasal sinus malignancies, nasopharyngeal cancer, oral cancer, laryngeal cancer, intracranial tumors, thyroid cancer, tongue cancer, lung cancer, esophageal cancer, breast cancer, gastric cancer, colorectal cancer, sigmoid colon and rectal cancer, liver cancer, pancreatic cancer and periampullary cancer, biliary tract cancer, kidney cancer, prostate cancer, bladder cancer, testicular malignancies, penile cancer, cervical cancer, endometrial cancer, ovarian cancer, fibrous histiocytic carcinoma, rhabdomyosarcoma, synovial sarcoma, melanoma, osteosarcoma, Ewing's sarcoma, leukemia, lymphoma and multiple myeloma.

[0068] Breast cancer is particularly preferred.

[0069] The present invention provides an anticancer drug comprising the vascular blocking agent described in any one of the above technical solutions and a pharmaceutically acceptable excipient.

[0070] The dosage form of the drug of the present invention is selected from one or more of tablets, capsules, granules, powders, patches, suspensions, syrups, oral solutions, injections, and suppositories.

[0071] The present invention does not limit the auxiliary materials, and those familiar to those skilled in the art are sufficient. The following auxiliary materials are optional:

[0072] Diluents: These are used to increase the bulk of a drug, making it easier to inject or prepare into other dosage forms. Common diluents include water, saline, and glucose solution.

[0073] Solvents: Serving as carriers for anti-tumor drugs, they dissolve the active ingredients, improving drug solubility and bioavailability. Different solvents have varying physical and chemical properties, and selecting the right solvent is crucial for maintaining drug stability and reducing toxicity. Common solvents include water, alcohols, oils, propylene glycol, polyethylene glycol, and ethylene glycol.

[0074] Emulsifiers: Used to disperse drugs in incompatible liquids to form a stable emulsion. Common emulsifiers include Tween and polyethylene glycol.

[0075] Osmotic agents: These are used to facilitate drug passage through cell membranes and improve absorption. Common osmotic agents include dimethyl sulfoxide and urea.

[0076] Sustained-release agents: These are used to delay the release of a drug, extending its duration of action. Common sustained-release agents include hydroxypropyl methylcellulose, gelatin, polylactic-co-glycolic acid copolymer, polycaprolactone, and methylcellulose.

[0077] Targeting agents: These are used to direct drugs to specific sites or cells. Common targeting agents include liposomes, nanoparticles, and antibody-drug conjugates.

[0078] Surfactants: By altering interfacial tension, they promote drug penetration through cell membranes or dissolve tissue barriers, enhancing drug delivery efficiency. They can also improve drug dispersibility and solubility, reduce drug aggregation, and increase drug bioavailability. Commonly used surfactants include Tween, polysorbate, and sodium lauryl sulfate.

[0079] Cosolvents: Used in conjunction with solvents to further enhance drug solubility, promote drug crystallization, and improve the stability of drug formulations. Common cosolvents include ethanol, isopropyl alcohol, and propylene glycol.

[0080] Adhesives: These are used for topical drug delivery, adhering drugs to the skin or mucosal surface to achieve sustained drug release and enhance local drug concentration. Adhesives include hydrogels, bioadhesives, and pressure-sensitive adhesives.

[0081] Chelating agents: such as EDTA, sodium citrate, etc., can chelate metal ions to prevent anti-tumor drugs from forming insoluble complexes with metal ions.

[0082] Antioxidants: They can prevent oxidative degradation of drugs, extend shelf life, scavenge free radicals produced during drug treatment, reduce oxidative stress, protect normal tissues from damage, and reduce toxicity and adverse reactions.

[0083] Enteric coating material: It protects anti-tumor drugs from degradation by gastric acid, allowing them to be released in the intestine and targeted to the tumor site

[0084] The polymeric vascular blocker provided by this invention can reside and accumulate at the tumor site for a long time, promoting the release of effective drugs. Initially, the drug rapidly releases CA4 through esterases within the tumor, disrupting tumor blood vessels and increasing tumor hypoxia levels. This promotes the release of hypoxia-sensitive AVE8063, further disrupting tumor blood vessels and enhancing tumor suppression. The drug provided by this invention, through its own action, amplifies the differences between tumors and normal tissues, achieving efficient and selective drug release at the tumor site. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Figure 1 Synthesis route of Azo-8063 (a) and H-NMR characterization (b);

[0086] Figure 2 The drug releases AVE8063 in response to hypoxia activation in vitro;

[0087] Figure 3 Tumor inhibition experiment in 4T1 tumor model: (a) Changes in tumor volume in mice; (b) Changes in body weight in mice. DETAILED DESCRIPTION

[0088] The present invention provides a vascular blocking agent, its preparation method, and use. Those skilled in the art can draw upon the disclosure herein and appropriately modify the process parameters to achieve the desired effect. It is particularly important to note that all similar substitutions and modifications will be readily apparent to those skilled in the art and fall within the scope of protection of the present invention. The methods and uses of the present invention have been described using preferred embodiments. It is apparent that those skilled in the art will be able to modify, alter, and combine the methods and uses herein to implement and apply the technology of the present invention without departing from the content, spirit, and scope of the present invention.

[0089] To further illustrate the present invention, a vascular blocking agent, its preparation method and application provided by the present invention are described in detail below with reference to examples.

[0090] Example 1:

[0091] We designed and synthesized the intermediate drug Azo-8063 ( Figure 1a). First, weigh the compound AVE8063 (946.1 mg, 3.0 mmol) and dissolve it in 30 mL of acetone, then add 30 mL of water and add 3.3 mL of hydrochloric acid solution (2M) under ice bath conditions; then weigh sodium nitrite (248.4 mg, 3.6 mmol) and dissolve it in 3 mL of water, add it dropwise into the reaction system, and react in an ice bath for 30 minutes. Use sodium hydroxide solution (1 M) to adjust the pH of the solution to 6. Weigh N-methyl-N-hydroxyethylaniline (258.4 mg, 1.72 mmol) and dissolve it in 3 mL of acetone and add it to the reaction system. After reacting at room temperature for 3 hours, add dichloromethane, wash with water 3 times, then wash with saturated brine 3 times, dry the organic layer with anhydrous sodium sulfate overnight, and separate the product Azo-8063 by column. Using DMSO-d6 as solvent 1 H NMR spectrum ( Figure 1 b).

[0092] Example 2:

[0093] 42.1 g (160.0 mmol) of γ-benzyl-L-glutamate-N-internal carboxylic anhydride monomer (BLG-NCA) was dissolved in 270 mL of ultra-dry N,N-dimethylformamide (DMF). After stirring to dissolve, 1.0 mL (1.0 mmol / L DMF solution) of n-hexylamine (n-HA) was added. The mixture was sealed and stirred at 25°C for 72 hours. Subsequently, 2.0 g (20.0 mmol) of acetic anhydride was added to the reaction system, and the reaction was continued for 6 hours. After completion of the reaction, the resulting reaction solution was poured into 2.0 L of diethyl ether, filtered, washed with diethyl ether, and dried under vacuum at room temperature for 24 hours to obtain the intermediate product, poly(γ-benzyl-L-glutamate) (PBLG). 10.0 g of the prepared poly(γ-benzyl-L-glutamate) was dissolved in 100 mL of dichloroacetic acid. 30 mL of a 33% by weight hydrogen bromide / glacial acetic acid solution was added with stirring, and the mixture was stirred at 30°C for 1 hour. The resulting reaction solution was then poured into 1.0 L of diethyl ether and centrifuged. The resulting precipitate was reconstituted with DMF, dialyzed against deionized water, and lyophilized to obtain acetyl-terminated poly(L-glutamic acid) polymer (PLG).

[0094] Example 3:

[0095] 1.5g of PLG and 3.0g of methoxypolyethylene glycol (mPEG, Mn = 5K) were weighed and dissolved in 50mL of ultra-dry DMF. 0.553g of triethylamine (TEA) and 0.534g of 4-dimethylaminopyridine (DMAP) were then weighed and dissolved in ultra-dry DMF and added to the reaction system. Next, 0.453g of 2,4,6-trichlorobenzoyl chloride (TBC) was weighed and slowly added to the reaction system. After this addition, 0.444g of Azo-8063 was dissolved in ultra-dry DMF and added to the reaction system. The temperature was maintained at 20-30°C. After a one-hour reaction, 0.037g of CA4 was added to the reaction system, followed by an additional 0.086g of TBC, and the reaction continued for another 2 hours. After completion of the reaction, the mixture was precipitated with anhydrous ether, redissolved, dialyzed once against water, and lyophilized to obtain the CA4 / Azo-8063 nanoparticles co-loaded with CA4 and Azo-8063.

[0096] Example 4

[0097] The synthesized nanodrug was dissolved in PBS solution at a concentration of 0.5 mg / mL, and the hydrated particle size of the nanodrugs with different drug co-load ratios was measured using a Malvern Zetasizer particle size analyzer (Table 1).

[0098] Example 5:

[0099] Sodium dithionite (NaS2O4) is often used as a substitute for azoreductase and can be used to detect the hypoxia-sensitive ability of azo bonds. Azo-8063 NPs solution 5mg / mL and Azo-8063 solution 0.5mg / mL were prepared, 300μL of each was mixed with 10 times the amount of NaS2O4 and incubated at 37℃ for 1h, and then 700μL of acetonitrile was added for HPLC testing. The results showed that both Azo-8063 NPs and Azo-8063 could effectively release AVE8063 ( Figure 2 ).

[0100] Example 6

[0101] Next, we investigated the therapeutic effects of CA4 / Azo-8063 nanoparticles with different co-loading ratios on the mouse breast cancer 4T1 tumor model. Figure 3 As shown in Figure 2, two tail vein injections of drugs were performed on day 0 and day 7. The curve of tumor volume change over time in mice ( Figure 3 a) and weight change curve ( Figure 3b) It can be found that the tumors in the mice in the PBS group grew extremely rapidly. During the treatment period, there was no significant difference in weight change between the CA4 and Azo-8063 co-loaded nanodrug group and the CA4 single-drug nanodrug group. There was no significant difference in weight change between the Azo-8063 nanodrug group and the PBS group, indicating that Azo-8063 is not the main cause of drug-induced weight loss. Azo-8063 has a certain safety profile, and CA4 is the main cause of weight loss caused by nanodrugs. The weight loss caused by all drugs during treatment was relatively mild and tended to recover quickly. From the tumor volume curve, it can be seen that the nanodrug bonded only with Azo-8063 also has a certain tumor inhibition effect. The tumor inhibition effect is significantly improved after co-loading with CA4. When the ratio of CA4 to Azo-8063 is 1:4, the tumor inhibition effect is optimal.

[0102] Table 1. Nanoparticle sizes of drugs co-loaded with different ratios of CA4 and Azo-8063

[0103]

[0104] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A vascular blocking agent represented by formula (I), in, R1 is selected from a C2-C10 straight-chain alkyl group, a C3-C10 branched-chain alkyl group, or a C6-C20 aryl group; R2 is selected from H, a C2-C10 straight-chain alkyl group, a C3-C10 branched-chain alkyl group, or a C6-C20 aryl group; R3 is selected from H or a cation; R4 is selected from unsubstituted C1-C20 alkyl or substituted C1-C20 alkyl; R5 is selected from a hydrogen atom or a C1-C6 alkyl acyl group; L1, L2, L3, L4 are independently selected from -CH2- or -CH2CH2-; L5 is selected from a C2-C10 straight chain alkyl group; E1 is selected from an amide bond or an ester bond; Z1 is selected from nitrogen (N), carbon (C) or oxygen (O); v, x, y, z are the percentages of the group, v+x+y+z=1, v>0, x>0, y>0, z>0; n is the degree of polymerization, 10≤n≤500.

2. The vascular blocking agent according to claim 1, characterized in that R1 is a C3-C8 straight-chain alkyl group, a C5-C8 branched-chain alkyl group, or a C8-C15 aryl group; R2 is a C3-C8 straight-chain alkyl group, a C5-C8 branched-chain alkyl group, or a C8-C15 aryl group; R3 is selected from a hydrogen atom, a metal cation or an organic cation.

3. The vascular blocking agent according to claim 1, characterized in that R4 is selected from an unsubstituted C2-C20 straight-chain alkyl group, an unsubstituted C3-C20 branched-chain alkyl group, a substituted C2-C20 straight-chain alkyl group, or a substituted C3-C20 branched-chain alkyl group; the substituent in the substituted C2-C20 straight-chain alkyl group is one or more of a hydroxyl group, an aldehyde group, an amino group, a sulfhydryl group, and a sugar residue; the substituent in the substituted C3-C20 branched-chain alkyl group is one or more of a hydroxyl group, an aldehyde group, an amino group, a sulfhydryl group, and a sugar residue; The R5 is selected from a hydrogen atom, an acetyl group or a propionyl group.

4. The vascular blocking agent according to claim 1, characterized in that The metal cation is selected from sodium ion and potassium ion; the organic cation is selected from ammonium ion or positively charged amino acid ion.

5. A method for preparing the vascular blocking agent according to any one of claims 1 to 4, characterized in that: The steps include: The compound of formula (II) and methoxypolyethylene glycol are dissolved in a solvent, triethylamine, 4-dimethylaminopyridine and Azo-8063 of formula (III) are added, reacted, and then CA4 is added to continue the reaction. After the reaction is completed, the mixture is precipitated with a solvent, redissolved, dialyzed, and then freeze-dried to obtain the product; 6. Use of the vascular blocking agent according to any one of claims 1 to 4 in the preparation of a drug for treating cancer.

7. The use according to claim 6, characterized in that The prevention and treatment include: causing tumor cell necrosis, inhibiting tumor growth, and destroying one or more of tumor blood vessels.

8. The use according to claim 6, wherein the cancer comprises one or more of nasal and paranasal sinus malignancies, nasopharyngeal cancer, oral cancer, laryngeal cancer, intracranial tumors, thyroid cancer, tongue cancer, lung cancer, esophageal cancer, breast cancer, gastric cancer, colorectal cancer, sigmoid colon and rectal cancer, liver cancer, pancreatic cancer and periampullary cancer, biliary tract cancer, kidney cancer, prostate cancer, bladder cancer, testicular malignancies, penile cancer, cervical cancer, endometrial cancer, ovarian cancer, fibrous histiocytic carcinoma, rhabdomyosarcoma, synovial sarcoma, melanoma, osteosarcoma, Ewing's sarcoma, leukemia, lymphoma and multiple myeloma.

9. An anticancer drug, characterized in that: The invention comprises the vascular blocking agent according to any one of claims 1 to 4 and pharmaceutically acceptable excipients.

10. The drug according to claim 9, characterized in that The dosage form of the drug is selected from one or more of tablets, capsules, granules, powders, patches, suspensions, syrups, oral solutions, injections, and suppositories.

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