Anti-tumor compound, self-assembled nano drug delivery system of anti-tumor compound and preparation method of self-assembled nano drug delivery system

Abstract

The invention belongs to the technical field of medicinal chemistry and medicinal preparations, and particularly relates to an anti-tumor compound, a self-assembled nano drug-loading system of the anti-tumor compound and a preparation method and application of the self-assembled nano drug-loading system. According to the novel antitumor compounds CPT-s-s-Lindeqvist and CPT-c-c-Lindeqvist and the preparation method thereof, the synthesis method of the two compounds is simple and convenient, and the raw material cost is low. CPT-s-Lindeqvist or CPT-c-c-Lindeqvist is prepared into vesicles through a film hydration method to obtain the self-assembled nano drug delivery system, accurate drug release in tumor tissue can be achieved, a certain slow release effect is shown, and the self-assembled nano drug delivery system has good biological safety and remarkable synergistic anti-tumor effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of pharmaceutical chemistry and pharmaceutical preparations, and specifically relates to an anti-tumor compound, a self-assembled nano drug delivery system of the anti-tumor compound, and a preparation method and application thereof. Background Art

[0002] Chemotherapy is an effective means of cancer treatment. However, due to limitations such as poor drug solubility, insufficient stability, and non-specific delivery, it is difficult for drugs to accurately enter the tumor site, and it inevitably damages healthy cells. The characteristics of the tumor microenvironment include high concentrations of glutathione, hypoxia, and low pH. These factors together cause tumor cells to show resistance to treatment and may aggravate the proliferation, migration, and invasion of tumor cells.

[0003] Disulfide bonds are a type of reduction-sensitive chemical bond that can break under the reduction of human glutathione. At the same time, studies have found that the concentration of glutathione (GSH) outside human cells is very low, about 2-20μmol / L, which is not enough to break disulfide bonds. The concentration of glutathione (2-10mmol / L) in tumor cells is usually about 7-10 times higher than that in normal cells, which is enough to break disulfide bonds. Disulfide-based drug delivery systems use glutathione highly expressed in tumor cells to trigger drug release, thereby improving the therapeutic effect and reducing damage to normal cells.

[0004] Polyoxometalates, also known as polyoxoacids, are composed of transition metal atoms (such as vanadium, molybdenum, tungsten, etc.) and heteroatoms (such as phosphorus, silicon, etc.) coordinated and bridged by oxygen atoms. They have the characteristics of structural plasticity, low toxicity, mature synthesis and low cost. Polyoxoacids exhibit broad-spectrum anti-tumor activity and induce tumor cell apoptosis through multiple mechanisms such as increasing intracellular ROS levels, reducing anti-apoptotic components, inhibiting ATP synthesis and inducing DNA damage. In particular, Lindqvist-type polyoxoacids are becoming a hot topic in the anti-tumor research of polyoxoacid drugs due to their good biocompatibility and cytotoxicity. Due to the negative charge on the surface of polyoxoacids, adjacent ion clusters will interact through electrostatic forces, van der Waals forces and hydrogen bonds to spontaneously form vesicles. Lindqvist-type polyacids are covalently linked to hydrophobic drugs to form stable amphiphilic vesicles in aqueous solution. They can prevent the uptake of the reticuloendothelial system through the enhanced permeability and retention (EPR) effect, thereby prolonging the half-life of the vesicles in the blood and enhancing their aggregation into the tumor microenvironment, which is beneficial for drug delivery and synergistic therapy.

[0005] Camptothecin (CPT) is a natural quinoline alkaloid. During the S phase of tumor cell DNA replication, camptothecin can specifically recognize and act on deoxyribonucleic acid TopoⅠ to form a stable "CPT-TopoⅠ-DNA" ternary complex, which inhibits the activity of topoisomerase Ⅰ to block the DNA synthesis of tumor cells, thereby mediating tumor cell death. However, since camptothecin is insoluble in water and has poor bioavailability, its administration dose is high, resulting in strong toxic side effects. These defects have greatly limited its application as an anti-tumor drug in clinical practice. Summary of the invention

[0006] In view of the problems existing in the above-mentioned prior art, the present invention modifies camptothecin by using polyacids, aiming to achieve the dual effects of enhancing efficacy and reducing toxicity, and significantly improve its water solubility.

[0007] The first object of the present invention is to provide an antitumor compound, which is a Lindqvist-type polyacid camptothecin hybrid compound.

[0008] The structural formula of the compound is: (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 25 H 23 N 2 O 5 S 2 ] or (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 27 H 23 N 2 O 5 ].

[0009] Among them (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 25 H 23 N 2 O 5 S 2], abbreviated as CPT-ss-Lindqvist in the present invention, which is a glutathione-responsive camptothecin hybrid compound of Lindqvist-type polyacid; (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 27 H 23 N 2 O 5 ], abbreviated as CPT-cc-Lindqvist in the present invention, is a Lindqvist-type polyacid camptothecin hybrid compound.

[0010] The second object of the present invention is to provide a method for preparing the above-mentioned antitumor compound, wherein the (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 25 H 23 N 2 O 5 S 2 ], which is a Lindqvist-type polyacid prepared by linking camptothecin with 3,3'-dithiodipropionic acid;

[0011] (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 27 H 23 N 2 O 5 ], which is a Lindqvist-type polyacid prepared by linking camptothecin with suberic acid.

[0012] (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 25 H 23 N 2 O 5 S 2 ], comprising the following steps:

[0013] (1) Put Na 2 WO4 ·2H 2 O、NaVO 3 and tris(hydroxymethyl)aminomethane are dissolved in purified water in sequence, and then heated and stirred at 85°C. After the mixture is completely dissolved, concentrated hydrochloric acid is used to adjust the pH value of the solution to 2.5-3, and then the reaction is continued for 24 hours to obtain an orange reaction solution; tetrabutylammonium bromide is dissolved in ultrapure water, and the orange reaction solution is slowly dripped into the tetrabutylammonium bromide solution drop by drop under stirring, and an orange-yellow precipitate is precipitated from the water, which is filtered, washed, and dried to obtain an orange-yellow powder solid, that is, an amino-modified Lindqvist-type polyacid (TBA) is obtained. 2 [V 3 W 3 O 16 (CH 2 O) 3 CNH 2 ];

[0014] (2) camptothecin, 3,3'-dithiodipropionic acid, 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide were dissolved in dichloromethane in sequence, reacted at room temperature for 24 hours, filtered, the solvent was removed under reduced pressure, and the product was purified by column chromatography to obtain CPT-ss-COOH;

[0015] (3) Under nitrogen protection, 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline (EEDQ) and CPT-ss-COOH were dissolved in acetonitrile in turn, and then heated to reflux and reacted for 35 minutes. Then, the Lindqvist-type polyacid was added to the reaction solution and refluxed for 24 hours. After the reaction, the obtained orange reaction solution was cooled to room temperature and concentrated under reduced pressure. The concentrated reaction solution was dropped into ethyl acetate to precipitate, and the target product CPT-ss-Lindqvist was obtained by suction filtration.

[0016] Above (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 25 H 23 N 2 O 5 S 2 ], the molar ratio of camptothecin, 3,3'-dithiodipropionic acid, 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide in step (2) is: 1:1-1.5:0.5-1:1-1.5, and the usage ratio of camptothecin to dichloromethane is 1g camptothecin: 50-100mL dichloromethane. (TBA) in step (3) 2 [V3 W 3 O 16 (CH 2 O) 3 CNH 2 The molar ratio of ], CPT-ss-COOH and 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline (EEDQ) is 1:1.5-2:2-3, and the amount of acetonitrile solvent is 1g (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNH 2 ]∶50~100mL acetonitrile solvent.

[0017] In the present invention, the synthetic route of CPT-ss-Lindqvist is as follows:

[0018] (1)

[0019] (2)

[0020] (3)

[0021] (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 27 H 23 N 2 O 5 ], comprising the following steps:

[0022] (1) Put Na 2 WO 4 ·2H 2 O、NaVO 3 and tris(hydroxymethyl)aminomethane are dissolved in purified water in sequence, and then heated and stirred at 85°C. After the mixture is completely dissolved, concentrated hydrochloric acid is used to adjust the pH value of the solution to 2.5-3, and then the reaction is continued for 24 hours to obtain an orange reaction solution; tetrabutylammonium bromide is dissolved in ultrapure water, and the orange reaction solution is slowly dripped into the tetrabutylammonium bromide solution drop by drop under stirring, and an orange-yellow precipitate is precipitated from the water, which is filtered, washed, and dried to obtain an orange-yellow powder solid, that is, an amino-modified Lindqvist-type polyacid (TBA) is obtained. 2 [V 3 W 3 O 16 (CH 2O) 3 CNH 2 ];

[0023] (2) Suberic acid, camptothecin, and 4-dimethylaminopyridine were dissolved in tetrahydrofuran in sequence and reacted at room temperature for 12 hours. The mixture was then washed, dried, filtered, and the solvent was removed under reduced pressure. The product was purified by column chromatography to obtain the product CPT-cc-COOH;

[0024] (3) Under nitrogen protection, 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline (EEDQ) and CPT-cc-COOH were dissolved in acetonitrile in turn, and then heated to reflux and reacted for 35 minutes. Then, the Lindqvist-type polyacid was added to the reaction solution and refluxed for 24 hours. After the reaction, the obtained orange reaction solution was cooled to room temperature and concentrated under reduced pressure. The concentrated reaction solution was dropped into ethyl acetate to precipitate, and the target product CPT-cc-Lindqvist was obtained by suction filtration.

[0025] In the present invention, the synthetic route of CPT-cc-Lindqvist is as follows:

[0026] (1)

[0027] (2)

[0028] (3)

[0029] Above (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 27 H 23 N 2 O 5 ], the molar ratio of camptothecin, suberic acid and 4-dimethylaminopyridine is 1:8-10:0.5-1, and the usage ratio of camptothecin to tetrahydrofuran is 1g camptothecin: 20-50mL tetrahydrofuran. Step (3) (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNH 2 The molar ratio of ], CPT-cc-COOH and 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline (EEDQ) is 1:1.5-2:2-3, and the amount of acetonitrile solvent is 1g (TBA) 2[V 3 W 3 O 16 (CH 2 O) 3 CNH 2 ]∶50~100mL acetonitrile solvent.

[0030] In the above-mentioned method for preparing the antitumor compound, the Na 2 WO 4 ·2H 2 O、NaVO 3 The molar ratio of Na to tris(hydroxymethyl)aminomethane is 1:1-1.5:0.5-1. 2 WO 4 ·2H 2 The dosage ratio of O to purified water is 1gNa 2 WO 4 ·2H 2 O: 10-15 mL purified water.

[0031] The third object of the present invention is to provide a self-assembled nano drug delivery system based on the anti-tumor compound and a preparation method thereof.

[0032] The self-assembled nano drug delivery system is composed of (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 25 H 23 N 2 O 5 S 2 ] or (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 27 H 23 N 2 O 5 ] is prepared, and the preparation method of the self-assembled nano drug delivery system comprises the following steps: taking (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 25 H 23 N 2 O 5 S 2 ] or (TBA)2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 27 H 23 N 2 O 5 ] was dissolved in acetonitrile and ultrasonicated for 10 min. The acetonitrile was removed by reduced pressure evaporation using a vacuum rotary evaporator. After a thin film of organic phase formed at the bottom of the round-bottom flask, it was immediately placed in a 50°C water bath for insulation. Purified water at 50°C was added to start hydration. After hydration for 4 h, vesicles were obtained.

[0033] The obtained vesicles are (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 25 H 23 N 2 O 5 S 2 ] or (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 27 H 23 N 2 O 5 ]Self-assembled nanodrug delivery system.

[0034] In the above-mentioned method for preparing the self-assembled nano drug delivery system of anti-tumor compounds, each 1 mg (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 25 H 23 N 2 O 5 S 2 ] or (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 27 H 23 N 2 O 5 ]The raw materials need to add 5-10 mL of acetonitrile and 5-10 mL of purified water.

[0035] A fourth object of the present invention is to provide (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 25 H 23 N 2 O 5 S 2 ] or (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 27 H 23 N 2 O 5 ] in the preparation of anti-tumor drugs and (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 25 H 23 N 2 O 5 S 2 ] or (TBA) 2 [V 3 W 3 O 16 (CH 2 O) 3 CNHCOC 27 H 23 N 2 O 5 ] Application of self-assembled nano drug delivery system in the preparation of anti-tumor drugs. The tumor is preferably lung cancer or liver cancer.

[0036] In the present invention, the term "vesicle" refers to amphiphilic molecules dispersed in water. Under the hydrophobic force, the hydrophilic end faces the water, the hydrophobic end faces away from the water, and orderly aggregation occurs between molecules, thereby spontaneously forming a class of molecular ordered assemblies with a closed double-layer structure, called vesicles (Chen, X.; Dong, W.; Zhang, X. Science China-Chemistry. 2010, 53, 1853, Neuhaus, F.; Mueller, D.; Tanasescu, R.; Balog, S.; Ishikawa, T.; Brezesinski, G.; Zumbuehl, A. Angewandte Chemie International Edition. 2017, 56, 6515.).

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) The present invention provides a new class of anti-tumor compounds CPT-ss-Lindqvist and CPT-cc-Lindqvist and preparation methods thereof. The synthesis methods of the two compounds are simple and the raw material cost is low. The solubility test results show that compared with camptothecin alone, the solubility of CPT-ss-Lindqvist compounds and CPT-cc-Lindqvist compounds in water is significantly increased. This means that after camptothecin is connected with Lindqvist-type polyacids, the water solubility of camptothecin can be improved. CPT-ss-Lindqvist has better water solubility due to the introduction of disulfide bonds.

[0039] (2) The present invention provides a CPT-ss-Lindqvist and CPT-cc-Lindqvist self-assembled nano drug delivery system and a preparation method thereof. The self-assembled nano drug delivery system is a CPT-ss-Lindqvist vesicle and a CPT-cc-Lindqvist vesicle. CPT-ss-Lindqvist or CPT-cc-Lindqvist is used to prepare vesicles by a thin film hydration method. After 1000 times dilution, the particle size of the drug-loaded vesicle remains stable, without obvious changes or vesicle depolymerization, and no drug precipitation is found. Therefore, the drug-loaded vesicle has good dilution stability, possesses ideal delivery system characteristics, and can quickly and efficiently enter target cells and tissues under non-steady-state conditions.

[0040] (3) Hemolytic test results showed that: 5-200 μg·mL -1Within the range, CPT-ss-Lindqvist vesicles or CPT-cc-Lindqvist vesicles have no obvious hemolytic activity on red blood cells, have good biocompatibility, are suitable for intravenous administration, and have no adverse effects on the body, indicating that the two vesicles have good blood compatibility.

[0041] (4) The CPT-ss-Lindqvist vesicles of the present invention are glutathione-responsive camptothecin vesicles of Lindqvist-type polyacids, which can be used for targeted delivery of camptothecin and glutathione-responsive drug release in tumor cells. In vitro release experiments show that CPT-ss-Lindqvist vesicles exist stably in normal body fluids. When encountering high concentrations of glutathione in tumor cells, the disulfide bonds are rapidly broken, the vesicles disintegrate, and camptothecin and Lindqvist-type polyacids are rapidly released. Compared with camptothecin and CPT-cc-Lindqvist vesicles, the vesicles have better anti-cancer effects, can achieve precise drug release in tumor tissues, and show a certain sustained-release effect. They have good biosafety and significant synergistic anti-tumor effects, solving the problem of poor therapeutic effects of anti-tumor drugs alone.

[0042] (5) The results of cytotoxicity experiments of CPT-ss-Lindqvist compounds and CPT-ss-Lindqvist vesicles showed that both CPT-ss-Lindqvist and CPT-ss-Lindqvist vesicles showed effective inhibition of the proliferation of A549 and Huh7 cancer cells. At the same time, they were highly safe for normal HUVEC and HEK293 cells, showing only low cytotoxicity. In addition, CPT-ss-Lindqvist vesicles had better anticancer effects, because the vesicle form was more easily taken up by cancer cells, thereby improving the bioavailability and anticancer efficiency of the drug.

[0043] The nano drug delivery system of the present invention can self-assemble into nano vesicles with uniform particle size in aqueous solution, which can prolong the circulation time of drugs in the blood and easily enrich in tumor sites through the EPR effect. Compared with camptothecin and CPT-cc-Lindqvist vesicles, CPT-ss-Lindqvist vesicles can passively target anticancer drugs camptothecin and polyacids to cancer cells, thereby achieving selective killing of cancer cells by anticancer drugs and reducing toxic side effects on normal cells.

[0044] (6) The cell uptake experiments of CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles showed that the uptake of drug vesicles by A549, Huh7, HUVEC and HEK293 cells was significantly higher than that of the free drug control group. CPT-ss-Lindqvist vesicles significantly enhanced the cellular uptake of drugs, especially in cancer cells. CPT-ss-Lindqvist and CPT-cc-Lindqvist vesicles successfully entered tumor cells and were mainly distributed in organelles such as lysosomes, verifying the effective uptake and localization of drug vesicles in tumor cells, thus supporting the potential application value of drug vesicles in anti-tumor therapy.

[0045] (7) The results of cytotoxicity experiments of CPT-ss-Lindqvist vesicle solution and CPT-cc-Lindqvist vesicle solution showed that at the same concentration, both CPT-ss-Lindqvist vesicle and CPT-cc-Lindqvist vesicle showed good inhibitory effects on the proliferation of A549 and Huh7 cancer cells, and both had high safety for HUVEC and HEK293 normal cells. However, compared with CPT-cc-Lindqvist vesicle, CPT-ss-Lindqvist vesicle had a higher inhibition rate. This is mainly due to the fact that the disulfide bonds are broken in the high concentration of glutathione in tumor cells, while such breaks are relatively rare in normal cells, thus significantly improving the safety and anti-cancer effect on normal cells.

[0046] (8) The amphiphilic CPT-ss-Lindqvist vesicles obtained in the present invention can precisely release Lindqvist-type polyacids and camptothecin in tumor tissues through the triggering of glutathione. The vesicles have multiple advantages such as synergistic anticancer, precise drug release, enhanced stability and solubility of camptothecin, enhanced permeability and EPR effect, and reduced toxic side effects, providing an innovative and efficient drug delivery solution for cancer treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 Schematic diagram of the preparation process of CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles.

[0048] Figure 2 For CPT-ss-Lindqvist and CPT-cc-Lindqvist 1 H NMR spectrum.

[0049] Figure 3Infrared spectra of CPT-ss-Lindqvist and CPT-cc-Lindqvist.

[0050] Figure 4 TEM image of CPT-ss-Lindqvist vesicles.

[0051] Figure 5 TEM image of CPT-cc-Lindqvist vesicles.

[0052] Figure 6 This is the particle size distribution diagram of CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles.

[0053] Figure 7 Particle size dilution stability of CPT-ss-Lindqvist vesicles.

[0054] Figure 8 Particle size dilution stability of CPT-cc-Lindqvist vesicles.

[0055] Fig. 9 Hemolytic activity of CPT-ss-Lindqvist vesicles.

[0056] Fig.10 The hemolytic activity of CPT-cc-Lindqvist vesicles.

[0057] Fig.11 The fluorescence spectrum changes of CPT-ss-Lindqvist vesicles before and after activation by glutathione in PBS solution.

[0058] Fig.12 This is an in vitro release experiment of CPT-ss-Lindqvist vesicles.

[0059] Fig.13 This is an in vitro release experiment of CPT-cc-Lindqvist vesicles.

[0060] Fig.14 This is a graph showing the effects of camptothecin, Lindqvist-type polyacids, CPT-ss-Lindqvist compounds and CPT-ss-Lindqvist vesicles on the activities of different types of tumor cells and normal cells.

[0061] Fig.15 The uptake rates of CPT and CPT-ss-Lindqvist vesicles by A549, Huh7, HUVEC and HEK293 cells.

[0062] Fig.16The intracellular distribution of CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles labeled with FITC was observed under CLSM.

[0063] Fig.17 This is a graph showing the effects of camptothecin, Lindqvist-type polyacids, CPT-cc-Lindqvist vesicles and CPT-ss-Lindqvist vesicles on the activities of different types of tumor cells and normal cells.

[0064] Table 1 compares the cell inhibition rates of CPT-ss-Lindqvist vesicles, CPT-ss-Lindqvist compounds and camptothecin alone on tumor cells and normal human cells at the same concentration.

[0065] Table 2 shows the IC values ​​of camptothecin, Lindqvist-type polyacids, CPT-ss-Lindqvist compounds and CPT-ss-Lindqvist vesicles for A549, Huh7, HUVEC and HEK293 cells 50 value.

[0066] Table 3 compares the cell inhibition rates of CPT-ss-Lindqvist vesicles, CPT-cc-Lindqvist vesicles and camptothecin alone on tumor cells and normal human cells at the same concentration.

[0067] Table 4 shows the IC values ​​of camptothecin, Lindqvist-type polyacids, CPT-cc-Lindqvist vesicles and CPT-ss-Lindqvist vesicles on A549, Huh7, HUVEC and HEK293 cells 50 value. DETAILED DESCRIPTION

[0068] The present invention will be further described below in conjunction with the accompanying drawings and examples. In order to allow those skilled in the art to better understand the present application, these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to limit the scope of the present invention. The change or adjustment of the relative relationship thereof shall also be regarded as the scope of the present invention without substantially changing the technical content.

[0069] In order to better understand the above technical scheme, the exemplary embodiments of the present invention are described in more detail below. Although exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0070] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and biological materials described are commercially available unless otherwise specified.

[0071] Example 1, Preparation of CPT-ss-Lindqvist Compound

[0072] (1) Put Na 2 WO 4 ·2H 2 O (3.30 g, 10 mmol), NaVO 3 (1.22 g, 10 mmol) and tris(hydroxymethyl)aminomethane (0.61 g, 5 mmol) were dissolved in 35 mL of purified water, and then heated and stirred at 85 °C. After the mixture was completely dissolved, concentrated hydrochloric acid was used to adjust the pH value of the solution to 2.5-3, and then the reaction was continued for 24 hours to obtain an orange reaction solution.

[0073] Tetrabutylammonium bromide (2.2 g, 6.8 mmol) was dissolved in 5 mL of ultrapure water. The orange reaction solution was slowly dripped into the tetrabutylammonium bromide solution drop by drop under stirring. An orange-yellow precipitate was precipitated from the water. The solution was filtered, washed, and dried to obtain an orange-yellow powdery solid, i.e., an amino-modified Lindqvist-type polyacid (TBA) was obtained. 2 [V 3 W 3 O 16 (CH 2 O) 3 CNH 2 ].

[0074] (2) Camptothecin (3.5 g, 10 mmol), 3,3'-dithiodipropionic acid (2.3 g, 11 mmol), 4-dimethylaminopyridine (1 g, 8.2 mmol) and N,N'-dicyclohexylcarbodiimide (3 g, 14.5 mmol) were dissolved in 200 mL of dichloromethane and reacted at room temperature for 24 hours. After filtration and removal of the solvent under reduced pressure, the product was purified by column chromatography with a mobile phase of dichloromethane: methanol = 30:1 to obtain a pale yellow solid CPT-ss-COOH.

[0075] (3) Under nitrogen protection, 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline (1.11 g, 4.5 mmol) and CPT-ss-COOH (1.62 g, 3 mmol) were dissolved in 200 mL of acetonitrile, heated to reflux and reacted for 35 minutes. Then, Lindqvist-type polyacid (2.34 g, 1.5 mmol) was added to the reaction solution and refluxed for 24 hours. After the reaction was completed, the obtained orange reaction solution was cooled to room temperature and concentrated under reduced pressure. The concentrated reaction solution was dropped into 400 mL of ethyl acetate to precipitate, and the precipitate obtained by suction filtration was dissolved in a small amount of acetonitrile and placed in ether vapor to precipitate, and finally the target product CPT-ss-Lindqvist was obtained.

[0076] Example 2, Preparation of CPT-cc-Lindqvist Compound

[0077] (1) Put Na 2 WO 4 ·2H 2 O (3.30 g, 10 mmol), NaVO 3 (1.22 g, 10 mmol) and tris(hydroxymethyl)aminomethane (0.61 g, 5 mmol) were dissolved in 35 mL of purified water, and then heated and stirred at 85 °C. After the mixture was completely dissolved, concentrated hydrochloric acid was used to adjust the pH value of the solution to 2.5-3, and then the reaction was continued for 24 hours to obtain an orange reaction solution.

[0078] Tetrabutylammonium bromide (2.2 g, 6.8 mmol) was dissolved in 5 mL of ultrapure water. The orange reaction solution was slowly dripped into the tetrabutylammonium bromide solution drop by drop under stirring. An orange-yellow precipitate was precipitated from the water. The solution was filtered, washed, and dried to obtain an orange-yellow powdery solid, i.e., an amino-modified Lindqvist-type polyacid (TBA) was obtained. 2 [V 3 W 3 O 16 (CH 2 O) 3 CNH 2 ].

[0079] (2) Suberic acid (9.91 g, 57 mmol), camptothecin (2 g, 5.7 mmol), and 4-dimethylaminopyridine (0.35 g, 2.9 mmol) were dissolved in 100 mL of tetrahydrofuran and reacted at room temperature for 12 hours. Then, saturated NaHCO 3The product was washed with aqueous solution (3×100 mL), 50 mM hydrochloric acid aqueous solution (1×100 mL) and saturated brine (1×100 mL). The organic layer was separated and dried over anhydrous sodium sulfate. After filtration and removal of the solvent under reduced pressure, the product was purified by column chromatography with a mobile phase of dichloromethane: methanol = 30:1 to obtain a light yellow solid CPT-cc-COOH.

[0080] (3) Under nitrogen protection, 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline (1.11 g, 4.5 mmol) and CPT-cc-COOH (1.50 g, 3 mmol) were dissolved in 200 mL of acetonitrile, heated to reflux and reacted for 35 minutes. Then, Lindqvist-type polyacid (2.34 g, 1.5 mmol) was added to the reaction solution and refluxed for 24 hours. After the reaction, the obtained orange reaction solution was cooled to room temperature and concentrated under reduced pressure. The concentrated reaction solution was dropped into 400 mL of ethyl acetate to precipitate, and the precipitate obtained by suction filtration was dissolved in a small amount of acetonitrile and placed in ether vapor to precipitate, and finally the target product CPT-cc-Lindqvist was obtained.

[0081] Attached Figure 2 For CPT-ss-Lindqvist and CPT-cc-Lindqvist 1 H NMR spectrum. In the hydrogen spectrum of CPT-ss-COOH, δ2.10 and δ2.89 are attributed to the characteristic peaks of hydrogen on the two carbon atoms of the disulfide bond, indicating that CPT successfully connected the disulfide bond. For the hydrogen spectrum of CPT-cc-COOH, δ4.20 and δ3.79 are characteristic peaks of hydrogen on the two carbon atoms. δ3.95 and δ5.30 belong to tris(hydroxymethyl)aminomethane connected to the polyacid, indicating that the polyacid has successfully achieved amino modification. The characteristic peak around δ8.70 in the hydrogen spectrum of CPT-ss-Lindqvist and CPT-cc-Lindqvist corresponds to the hydrogen atoms in the benzene ring of CPT. In addition, it also contains the characteristic peaks of polyacids and CPT modified compounds, proving that the two substances were successfully synthesized.

[0082] Attached Figure 3 Infrared spectra of CPT-ss-Lindqvist and CPT-cc-Lindqvist. -1 The strong absorption peaks near 960 cm are the stretching vibrations of VO and WO bonds, which is consistent with the typical Lindqvist polyacid structure. -1 There are strong stretching vibration peaks of V=O and W=O nearby. In the infrared spectrum of CPT modified products, 3430cm -1 is the stretching vibration peak of -OH, 2929cm -1 、2849cm-1 is the stretching vibration peak of CH on saturated C, 1650cm -1 The stretching vibration peak of C=O on the formed ester bond. 1650cm -1 The stretching vibration peak of C=O on the formed ester bond is more obvious, indicating that Lindqvist polyacid is connected to CPT. The characteristic peak of Lindqvist polyacid appears in the final product, indicating that CPT is connected to Lindqvist polyacid, and CPT-ss-Lindqvist and CPT-cc-Lindqvist are successfully synthesized.

[0083] Example 3: Preparation of CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles by thin film hydration method

[0084] Weigh 2.0 mg of CPT-ss-Lindqvist or CPT-cc-Lindqvist compound and add 15 mL of acetonitrile to completely dissolve it. Ultrasonicate for 10 minutes, and use a vacuum rotary evaporator to remove acetonitrile under reduced pressure at 40°C. After the organic phase forms a thin film at the bottom of the round-bottom flask, immediately put it in a 50°C water bath for 5 minutes, add 10 mL of 50°C pure water to start hydration, and after hydration for 4 hours, CPT-ss-Lindqvist vesicles or CPT-cc-Lindqvist vesicles are obtained. TEM observations show that a relatively regular hollow spherical nanovesicle structure ( Figure 4 and Figure 5 Then, the particle size of CPT-ss-Lindqvist vesicles or CPT-cc-Lindqvist vesicles was measured by Malvern particle size analyzer to be about 250nm and 230nm respectively ( Figure 6 ).

[0085] Example 4: Preparation of CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles by dialysis

[0086] 2 mg of CPT-ss-Lindqvist or CPT-cc-Lindqvist compound was accurately weighed and dissolved in 0.5 mL of acetonitrile, and then slowly dripped into a mixed solvent of 4.5 mL of acetonitrile (2 mL) and water (2.5 mL) so that the final mixed solution ratio was acetonitrile / water = 1 / 1 (v / v). The mixed solution was then transferred to a dialysis bag with a molecular weight of 1000, and a CPT-ss-Lindqvist vesicle solution or a CPT-cc-Lindqvist vesicle solution was obtained after 24 hours of dialysis. The dialysis medium was ultrapure water.

[0087] Experimental Example 1: Solubility determination of CPT-ss-Lindqvist and CPT-cc-Lindqvist compounds

[0088] (1) Experimental basis: General Notes of the 2020 edition of the Chinese Pharmacopoeia

[0089] (2) Operation method: Weigh 1 g of finely powdered camptothecin, Lindqvist-type polyacid, CPT-ss-Lindqvist compound and CPT-cc-Lindqvist compound respectively, place in a volumetric flask, add 10 mL of water (25°C ± 2°C) each time, and shake vigorously for 30 seconds every 5 minutes; observe the dissolution within 30 minutes. If there are no visible solute particles or droplets, it is considered to be completely dissolved. If not dissolved, continue to add, and follow the above method for each addition until it is completely dissolved.

[0090] (3) Experimental results

[0091] Compound Solubility Camptothecin Very insoluble in water Lindqvist-type polyacid 5.88g / L CPT-ss-Lindqvist 2.70g / L CPT-cc-Lindqvist 2.32g / L

[0092] The results showed that the solubility of CPT-ss-Lindqvist and CPT-cc-Lindqvist compounds in water was significantly increased compared with camptothecin alone. This means that the water solubility of camptothecin can be improved after it is linked to the Lindqvist-type polyacid. CPT-ss-Lindqvist has better water solubility due to the introduction of disulfide bonds.

[0093] Experimental Example 2: Dilution Stability Study of CPT-ss-Lindqvist Vesicle Solution and CPT-cc-Lindqvist Vesicle Solution

[0094] The CPT-ss-Lindqvist vesicle solution and CPT-cc-Lindqvist vesicle solution obtained by dialysis were used as mother solutions and diluted 0 times, 10 times, 100 times, and 1000 times, respectively. The particle size and particle size distribution were measured to investigate whether the vesicles could maintain structural stability at different dilution multiples.

[0095] Attached Figure 7 With attached Figure 8The following are the particle size comparisons of CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicle solutions at different dilution multiples. After 1000-fold dilution, the particle size of CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles remained stable, without obvious changes or vesicle depolymerization, and no drug precipitation was found. Therefore, this type of drug-loaded vesicle has good dilution stability and vesicle depolymerization characteristics at low critical concentrations, and has ideal delivery system characteristics, which can quickly and efficiently enter target cells and tissues under non-steady-state conditions.

[0096] Experimental Example 3: Hemolytic activity of CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles

[0097] Collect mouse blood, dilute with an equal volume of saline, and centrifuge to collect the pellet containing red blood cells. Wash the concentrated red blood cells three times, and then resuspend them in PBS (pH 7.4) to obtain a 2% (v / v) red blood cell suspension. Add 1 mL of 2% red blood cell suspension to each centrifuge tube, and then add 3 mL of 5-200 μg mL -1 CPT-ss-Lindqvist vesicle solution or CPT-cc-Lindqvist vesicle solution. Water and phosphate buffered saline (pH 7.4) were used as positive (maximum hemolysis) and negative controls (minimum hemolysis). After incubation at 37°C for 4 hours, the above experimental and control groups were centrifuged. The absorbance of the supernatant of the experimental and control groups was measured at 578 nm using an ELISA reader.

[0098] Attached Fig. 9 With attached Fig.10 The hemolytic activity of CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles. The results showed that the hemolytic activity of CPT-ss-Lindqvist vesicles was 5-200 μg·mL -1 Within the range, CPT-ss-Lindqvist vesicles or CPT-cc-Lindqvist vesicles have no obvious hemolytic activity on red blood cells, have good biocompatibility, are suitable for intravenous administration, and have no adverse effects on the body, indicating that the two vesicles have good blood compatibility.

[0099] Experimental Example 4: In vitro drug release experiment of CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles

[0100] A 10 μM CPT-ss-Lindqvist vesicle solution was selected for measurement in PBS solvent (pH 7.4), incubated with different concentrations of glutathione at 37°C for 1 h, and the fluorescence spectrum was measured using a fluorescence spectrophotometer.

[0101] The in vitro release behavior of CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles was studied in pH 7.4+10mM GSH, pH 7.4+5mM GSH, pH 7.4+10μM GSH, and pH 7.4. A certain amount of freshly prepared CPT-ss-Lindqvist vesicles or CPT-cc-Lindqvist vesicle solution was transferred to a dialysis bag (MWCO: 1000Da), and then placed in 50mL of release medium at 37°C and gently shaken at 100rpm. At the predetermined time point, 2mL of the release solution was taken and an equal amount of fresh release medium was added. The CPT concentration was measured at 363nm using a UV-visible spectrophotometer.

[0102] Attached Fig.11 The fluorescence spectra of CPT-ss-Lindqvist vesicles before and after activation by glutathione in PBS solution. When the concentration of glutathione gradually increased, the fluorescence intensity of the solution at 425nm increased significantly in a linear manner. The data showed that the disulfide bonds of CPT-ss-Lindqvist can be cleaved by glutathione in a dose-dependent manner.

[0103] Attached Fig.12 With attached Fig.13 The release curves of CPT in vitro in the presence of pH 7.4+10mM GSH, pH 7.4+5mM GSH, pH 7.4+10μM GSH, and pH7.4 for CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles, respectively. pH 7.4, pH 7.4+10mM GSH, and pH 7.4+10μM GSH were used to simulate blood circulation and intracellular and extracellular conditions. As a control, under 10mM GSH conditions, CPT-cc-Lindqvist released almost no CPT within 48 hours. Under 10mM GSH, CPT-ss-Lindqvist vesicles in the tumor cell environment released CPT rapidly. The results show that CPT-ss-Lindqvist vesicles have high stability, and because they contain disulfide bonds, controlled release of drugs can be achieved according to changes in GSH in the tumor environment.

[0104] Experimental Example 5: Cytotoxicity Experiment of CPT-ss-Lindqvist Compounds and CPT-ss-Lindqvist Vesicles

[0105] The inhibitory ability of CPT-ss-Lindqvist compounds and vesicles on lung cancer cells (A549) and liver cancer cells (Huh7) and their cytotoxicity on normal human cells human umbilical vein endothelial cells (HUVEC) and human embryonic kidney cells (HEK293) were tested.

[0106] Method: The cells were digested, counted, and diluted to a concentration of 5×10 4 Then, 100 μL of the cell suspension was inoculated into each well of a 96-well plate and the 96-well plate was placed at 37°C and 5% CO 2 Incubate in an incubator for 24 h. Then, CPT-ss-Lindqvist vesicles were diluted to different concentrations (20 μg mL -1 , 40 μg·mL -1 , 60μg·mL -1 , 100 μg·mL -1 , 200 μg·mL -1 ), 100 μL of medium containing vesicles was added to each well, 3 replicates were set for each concentration, and a blank group and a control group were set up. No cells were inoculated in the blank group, and DMEM complete medium without vesicles was added to the control group. The 96-well plate was then placed at 37°C and 5% CO 2 After incubation in the incubator for 24 hours, add 10 μL of MTT to each well, then incubate in the dark for another 4 hours, remove the culture medium, add 100 μL of dimethyl sulfoxide (DMSO) to each well, and gently mix on a shaker for 10 minutes. Finally, measure the OD value at 490 nm on a microplate reader to calculate the cell survival rate. The formula for calculating the cell survival rate is:

[0107]

[0108] Cell inhibition rate (%) = 1 - cell survival rate

[0109] Results Fig.14 and Table 1.

[0110] Table 1

[0111]

[0112] Table 1 shows the concentrations of -1The inhibition rates of CPT-ss-Lindqvist vesicles, CPT-ss-Lindqvist compounds and CPT were compared. The results showed that at the same concentration, both CPT-ss-Lindqvist and CPT-ss-Lindqvist vesicles showed effective inhibition of A549 and Huh7 cancer cell proliferation. At the same time, they were more safe for HUVEC and HEK293 normal cells, showing only low cytotoxicity. In addition, CPT-ss-Lindqvist vesicles have better anticancer effects, which is because the vesicle form is more easily taken up by cancer cells, thereby improving the bioavailability and anticancer efficiency of the drug.

[0113] Fig.14 The results in Table 1 show that the cell activity of normal cells HUVEC and HEK293 under the action of CPT-ss-Lindqvist vesicles and CPT-ss-Lindqvist compounds is higher than that of camptothecin alone. CPT-ss-Lindqvist vesicles break disulfide bonds in tumor cells, but not in normal cells. This makes it difficult for the drug to be released in normal cells, thereby reducing its toxicity to normal cells. IC of normal cells cultured for 24 hours with four drugs at different concentrations 50 (Table 2), the results indicate that CPT-ss-Lindqvist vesicles have better safety and can effectively reduce toxicity to normal cells.

[0114] Table 2

[0115]

[0116] Experimental Example 6: Cellular uptake experiment of CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles

[0117] Cellular uptake of fluorescein isothiocyanate (FITC)-labeled CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles was observed on a confocal laser scanning microscope (CLSM). Typically, cells were seeded in 6-well plates and cultured overnight. After an initial culture of 12 hours, CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles were introduced into the culture medium. After 8 hours of incubation, the cells were rinsed with PBS, fixed with 4% paraformaldehyde solution, and stained with Lyso-Tracker Red solution. Subsequently, the cells were observed using CLSM. Quantification was performed by flow cytometry.

[0118] Attached Fig.15The uptake rates of CPT and CPT-ss-Lindqvist vesicles by A549, Huh7, HUVEC and HEK293 cells were significantly higher than those of the free drug control group. CPT-ss-Lindqvist vesicles significantly enhanced the cellular uptake of drugs, especially in cancer cells.

[0119] Attached Fig.16 The intracellular distribution of CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles labeled with FITC under CLSM observation. CLSM imaging showed that the FITC signal co-localized with tumor cells, indicating that CPT-ss-Lindqvist and CPT-cc-Lindqvist vesicles successfully entered tumor cells and were mainly distributed in organelles such as lysosomes, verifying the effective uptake and localization of drug vesicles in tumor cells, thereby supporting the potential application value of drug vesicles in anti-tumor therapy.

[0120] Experimental Example 7: Cytotoxicity experiment of CPT-ss-Lindqvist vesicle solution and CPT-cc-Lindqvist vesicle solution

[0121] The inhibitory ability of the CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles prepared by the present invention on lung cancer cells (A549) and liver cancer cells (Huh7) and the cytotoxicity on normal human cells human umbilical vein endothelial cells (HUVEC) and human embryonic kidney cells (HEK293) were tested.

[0122] Results Fig.17 and Table 3.

[0123] Table 3

[0124]

[0125] Table 3 shows the concentrations of -1The inhibitory effects of CPT-ss-Lindqvist and CPT-cc-Lindqvist drug vesicles on cancer cells and normal cells were studied. The results showed that at the same concentration, both CPT-ss-Lindqvist vesicles and CPT-cc-Lindqvist vesicles showed good inhibitory effects on the proliferation of A549 and Huh7 cancer cells, and both had high safety for HUVEC and HEK293 normal cells. However, compared with CPT-cc-Lindqvist, CPT-ss-Lindqvist vesicles had a higher inhibition rate. This is mainly due to the fact that the disulfide bonds are broken in the high concentration of glutathione in tumor cells, while this breakage is relatively rare in normal cells, thus significantly improving the safety and anti-cancer effect on normal cells.

[0126] Table 4

[0127]

[0128] Fig.17 The results in Table 4 show that for normal human cells HUVEC and HEK293, the cell activity in the CPT-ss-Lindqvist vesicle environment is higher than that in the CPT-cc-Lindqvist vesicle environment and the camptothecin environment alone. IC of normal cells cultured for 24 hours with four drugs at different concentrations 50 (Table 4), indicating that CPT-cc-Lindqvist vesicles have a certain degree of safety and can effectively reduce the toxic effects on normal cells. CPT-cc-Lindqvist vesicles showed certain cell proliferation inhibition activity against two cancer cells, but the anticancer effect was not as good as that of CPT-ss-Lindqvist vesicles. This is because the CPT drug molecules cannot be released from the vesicles efficiently. This result also confirms that CPT-ss-Lindqvist containing disulfide bonds can respond to high concentrations of glutathione in tumor cells, and has better anticancer effects and higher safety than CPT-cc-Lindqvist.

Claims

1. An antitumor compound, wherein the compound is a Lindqvist-type polyacid camptothecin hybrid compound, characterized in that: The structural formula of the compound is: (TBA)2[V3W3O 16 (CH2O)3CNHCOC 25 H 23 N2O5S2] or (TBA)2[V3W3O 16 (CH2O)3CNHCOC 27 H 23 N2O5].

2. The method for preparing the antitumor compound according to claim 1, characterized in that: The (TBA)2[V3W3O 16 (CH2O)3CNHCOC 25 H 23 N2O5S2], which is a Lindqvist-type polyacid prepared by linking camptothecin with 3,3'-dithiodipropionic acid; The (TBA)2[V3W3O 16 (CH2O)3CNHCOC 27 H 23 N2O5], which is a Lindqvist-type polyacid prepared by linking camptothecin with suberic acid.

3. The method for preparing the antitumor compound according to claim 2, characterized in that: The (TBA)2[V3W3O 16 (CH2O)3CNHCOC 25 H 23 The preparation method of N2O5S2] comprises the following steps: (1) Na2WO4·2H2O, NaVO3 and tris(hydroxymethyl)aminomethane are dissolved in purified water in sequence, and then heated and stirred at 85°C. After the mixture is completely dissolved, concentrated hydrochloric acid is used to adjust the pH value of the solution to 2.5-3, and then the reaction is continued for 24 hours to obtain an orange reaction solution; tetrabutylammonium bromide is dissolved in ultrapure water, and the orange reaction solution is slowly dripped into the tetrabutylammonium bromide solution drop by drop under stirring, and an orange-yellow precipitate is precipitated from the water, which is filtered, washed, and dried to obtain an orange-yellow powder solid, that is, an amino-modified Lindqvist-type polyacid (TBA)2[V3W3O 16 (CH2O)3CNH2]; (2) camptothecin, 3,3'-dithiodipropionic acid, 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide were dissolved in dichloromethane in sequence, reacted at room temperature for 24 hours, filtered, the solvent was removed under reduced pressure, and the product was purified by column chromatography to obtain CPT-ss-COOH; (3) Under nitrogen protection, 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline (EEDQ) and CPT-ss-COOH were dissolved in acetonitrile in turn, and then heated to reflux and reacted for 35 minutes. Then, the Lindqvist-type polyacid was added to the reaction solution and refluxed for 24 hours. After the reaction, the obtained orange reaction solution was cooled to room temperature and concentrated under reduced pressure. The concentrated reaction solution was dropped into ethyl acetate to precipitate, and the target product CPT-ss-Lindqvist was obtained by suction filtration.

4. The method for preparing the antitumor compound according to claim 2, characterized in that: The (TBA)2[V3W3O 16 (CH2O)3CNHCOC 27 H 23 The preparation method of N2O5] comprises the following steps: (1) Na2WO4·2H2O, NaVO3 and tris(hydroxymethyl)aminomethane are dissolved in purified water in sequence, and then heated and stirred at 85°C. After the mixture is completely dissolved, concentrated hydrochloric acid is used to adjust the pH value of the solution to 2.5-3, and then the reaction is continued for 24 hours to obtain an orange reaction solution; tetrabutylammonium bromide is dissolved in ultrapure water, and the orange reaction solution is slowly dripped into the tetrabutylammonium bromide solution drop by drop under stirring, and an orange-yellow precipitate is precipitated from the water, which is filtered, washed, and dried to obtain an orange-yellow powder solid, that is, an amino-modified Lindqvist-type polyacid (TBA)2[V3W3O 16 (CH2O)3CNH2]; (2) Suberic acid, camptothecin, and 4-dimethylaminopyridine were dissolved in tetrahydrofuran in sequence and reacted at room temperature for 12 hours. The mixture was then washed, dried, filtered, and the solvent was removed under reduced pressure. The product was purified by column chromatography to obtain CPT-cc-COOH; (3) Under nitrogen protection, 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline (EEDQ) and CPT-cc-COOH were dissolved in acetonitrile in turn, and then heated to reflux and reacted for 35 minutes. Then, the Lindqvist-type polyacid was added to the reaction solution and refluxed for 24 hours. After the reaction, the obtained orange reaction solution was cooled to room temperature and concentrated under reduced pressure. The concentrated reaction solution was dropped into ethyl acetate to precipitate, and the target product CPT-cc-Lindqvist was obtained by suction filtration.

5. The method for preparing the antitumor compound according to claim 3 or 4, characterized in that: The molar ratio of Na2WO4·2H2O, NaVO3 and tris(hydroxymethyl)aminomethane in step (1) is 1:1-1.5:0.5-1, and the usage ratio of Na2WO4·2H2O to purified water is 1g Na2WO4·2H2O: 10-15mL purified water.

6. The method for preparing the antitumor compound according to claim 3, characterized in that: The molar ratio of camptothecin, 3,3'-dithiodipropionic acid, 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide in step (2) is 1:1-1.5:0.5-1:1-1.5, and the usage ratio of camptothecin to dichloromethane is 1g camptothecin: 50-100mL dichloromethane.

7. The method for preparing the antitumor compound according to claim 3, characterized in that: Step (3) (TBA)2[V3W3O 16 The molar ratio of [(CH2O)3CNH2], CPT-ss-COOH and 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline (EEDQ) is 1:1.5-2:2-3, and the amount of acetonitrile solvent is 1g (TBA)2[V3W3O 16 (CH2O)3CNH2]: 50-100 mL acetonitrile solvent.

8. The method for preparing the antitumor compound according to claim 4, characterized in that: The molar ratio of camptothecin, suberic acid and 4-dimethylaminopyridine in step (2) is 1:8-10:0.5-1, and the usage ratio of camptothecin to tetrahydrofuran is 1g camptothecin: 20-50mL tetrahydrofuran. Step (3) (TBA)2[V3W3O 16 The molar ratio of (CH2O)3CNH2], CPT-cc-COOH and 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline (EEDQ) is 1:1.5-2:2-3, and the amount of acetonitrile solvent is 1g (TBA)2[V3W3O 16 (CH2O)3CNH2]: 50-100 mL acetonitrile solvent.

9. The self-assembled nano drug delivery system based on the anti-tumor compound according to claim 1, characterized in that: The self-assembled nano drug delivery system is composed of (TBA)2[V3W3O 16 (CH2O)3CNHCOC 25 H 23 N2O5S2] or (TBA)2[V3W3O 16 (CH2O)3CNHCOC 27 H 23 N2O5] prepared, The preparation method comprises the following steps: taking (TBA)2[V3W3O 16 (CH2O)3CNHCOC 25 H 23 N2O5S2] or (TBA)2[V3W3O 16 (CH2O)3CNHCOC 27 H 23 N2O5] was dissolved in acetonitrile and sonicated for 10 min. The acetonitrile was removed by reduced pressure evaporation using a vacuum rotary evaporator. After the organic phase formed a thin film at the bottom of the round-bottom flask, it was immediately placed in a 50°C water bath for insulation. 50°C purified water was added to start hydration. Vesicles were obtained after hydration for 4 h.

10. The self-assembled nano drug delivery system of anti-tumor compounds according to claim 9, characterized in that: In the preparation method, each 1 mg (TBA) 2 [V3W3O 16 (CH2O)3CNHCOC 25 H 23 N2O5S2] or (TBA)2[V3W3O 16 (CH2O)3CNHCOC 27 H 23 N2O5] raw materials need to add 5-10mL acetonitrile and 5-10mL purified water.

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