Nano-covalent organic framework for delivering NO and doped with cupric peroxide, its preparation method and application

Abstract

The present invention relates to a nano-covalent organic framework for delivering NO and doped with cupric peroxide, and its preparation method and application. The covalent organic framework is a Schiff base type covalent organic framework in which 1,3,5-tris(4-aminophenyl)benzene and 2,5-diallyloxy terephthalaldehyde are connected by carbon-nitrogen double bonds. The particle size of CuO2@COF-SNO is less than 200 nm, and the mass ratio of the modified COF to NO is about 1:0.01-0.04, and the mass ratio of COF to CuO2 is 1:0.008-0.015. After the COF material in the present invention is successfully connected with NO, COF-SNO has good ability to deliver nitric oxide, so it has great potential in tumor gas therapy. After loading cupric peroxide, cupric peroxide can decompose into copper ions and hydrogen peroxide in tumor cells, triggering a Fenton-like catalytic reaction to generate highly toxic hydroxyl radicals and promote the release of nitric oxide. The combination of gas therapy and chemodynamic therapy greatly improves the therapeutic effect of tumors and has great potential in tumor treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of nanomaterial preparation, and specifically relates to a nano-covalent organic framework for delivering NO and doped with cupric peroxide, and a preparation method and application thereof. Background Art

[0002] The information disclosed in the background art of the present invention is only intended to increase the understanding of the overall background of the present invention, and does not necessarily be regarded as an admission or imply in any form that this information constitutes the prior art that has been well known to those skilled in the art.

[0003] Globally, cancer is one of the most serious diseases threatening human health. Covalent organic frameworks are a class of organic crystalline porous materials discovered in the early 21st century. Due to their high crystallinity, high inherent porosity, good structural regularity, diverse functions, strong design flexibility, and excellent stability, they have become a class of extremely attractive emerging materials. In some cases, they can be used to load therapeutic drugs through covalent bonds, and the organic building blocks of COF can also be post-modified to specifically bind to biomarkers. The uniqueness of COF makes it a promising nanocarrier for tumor treatment applications.

[0004] In the field of cancer treatment, more and more studies have shown that NO has direct or indirect anti-tumor effects at different concentrations, but its direct application in vivo still has limitations. For example, NO can promote the growth of cancer cells at low concentrations (<nM level), and only within a certain concentration range can NO play an effective anti-tumor role; the half-life of NO in vivo is very short, and it is difficult to reach the desired level of free NO concentration in tumor tissues. Summary of the Invention

[0005] Aiming at the problems that NO has a short half-life and its concentration is not easy to control in vivo, the present invention constructs a nano-covalent organic framework for delivering nitric oxide and doped with cupric peroxide, which is used for synergistic chemodynamic therapy and gas therapy. Cupric peroxide can only decompose in the acidic tumor microenvironment, thereby releasing a large amount of copper ions and abundant H2O2, so as to achieve efficient chemodynamic therapy and considerable NO release performance, effectively avoiding premature release of NO, and thus achieving better treatment effects.

[0006] In order to achieve the above object, the technical solution of the present invention is described as follows:

[0007] In the first aspect of the present invention, there is provided a delivery of NO and a doped cupric peroxide nano covalent organic framework CuO2@COF-SNO. First, the covalent organic framework and 1,2-ethanedithiol are successfully connected through the reaction of double bonds and mercapto groups. Next, the mercapto groups exposed on the outside of the material are nitrated with tert-butyl nitrite to successfully connect NO. Finally, cupric peroxide nanoparticles are in-situ synthesized on the material. The covalent organic framework is a Schiff base type covalent organic framework in which 1,3,5-tris(4-aminophenyl)benzene and 2,5-diallyloxy terephthalaldehyde are connected by carbon-nitrogen double bonds.

[0008] The particle sizes of the Schiff base type covalent organic framework in which 1,3,5-tris(4-aminophenyl)benzene and 2,5-diallyloxy terephthalaldehyde are connected by carbon-nitrogen double bonds in the present invention, after connecting NO and loading cupric peroxide, are all within 200 nm and can accumulate at the tumor site through the EPR effect; because the Schiff base type covalent organic framework in which 1,3,5-tris(4-aminophenyl)benzene and 2,5-diallyloxy terephthalaldehyde are connected by carbon-nitrogen double bonds has free olefinic bonds, it can react with the mercapto groups of 1,2-ethanedithiol, and then connect NO through nitration with tert-butyl nitrite, having a strong binding ability; and the high porosity and electrostatic interaction of COF can adsorb Cu 2+ , thus in-situ synthesizing cupric peroxide on the material.

[0009] In the second aspect of the present invention, there is provided a preparation method of the cupric peroxide nano covalent organic framework CuO2@COF-SNO doped with nitric oxide as described in the first aspect.

[0010] The preparation method is as follows: 1,3,5-tris(4-aminophenyl)benzene and 2,5-diallyloxy-1,4-terephthalaldehyde are subjected to a Schiff base reaction to obtain a Schiff base type covalent organic framework COF connected by carbon-nitrogen double bonds;

[0011] In trifluorotoluene, COF and 1,2-ethanedithiol react to obtain a mercapto-modified nano covalent organic framework COF-SH;

[0012] In a mixed solution of methanol and toluene, COF-SH is nitrated with tert-butyl nitrite to obtain a nano covalent organic framework COF-SNO loaded with NO;

[0013] In water, COF-SNO and CuCl2·2H2O are stirred for a certain time, and then centrifuged. The centrifuged precipitate is dispersed in a mixed solution containing a certain amount of sodium hydroxide and hydrogen peroxide and stirred for a certain time to obtain CuO2@COF-SNO.

[0014] In the third aspect of the present invention, there is provided an application of the first-mentioned delivery of nitric oxide and doped cupric peroxide nano-covalent organic framework CuO2@COF-SNO in the preparation of antitumor agents.

[0015] The specific embodiments of the present invention have the following beneficial effects: In the present invention, NO was successfully modified on the nano-COF material formed by 1,3,5-tris(4-aminophenyl)benzene and 2,5-diallyloxyterephthalaldehyde, and cupric peroxide was successfully doped. The size of the material became slightly larger before and after modification, but it was still within 200 nm. After the COF material surface was successfully modified with NO, COF-SNO had good NO delivery and release capabilities, so it had great potential in the gas therapy of tumors. After doping cupric peroxide, it could stimulate the release of NO and generate hydrogen peroxide in the tumor microenvironment, exerting the effect of chemodynamic therapy. The COF, COF-SNO, and CuO2@COF-SNO prepared in the present invention all had good biocompatibility. Combining its gas therapy and chemodynamic therapy had great potential in the combined treatment of tumors. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0017] Figure 1 TEM images of the nano-COF, COF-SNO, and CuO2@COF-SNO prepared in Example 1 of the present invention, where Figure 1 a is the TEM image of the nano-COF, Figure 1 b is the TEM image of COF-SNO, Figure 1 c is the TEM image of the nano CuO2@COF-SNO;

[0018] Figure 2 X-ray powder diffraction patterns of the COF, COF-SNO, and CuO2@COF-SNO prepared in Example 1 of the present invention;

[0019] Figure 3 UV-visible absorption spectra of the COF, COF-SNO, and CuO2@COF-SNO prepared in Example 1 of the present invention;

[0020] Figure 4 Infrared-visible absorption spectra of the COF, COF-SNO, and CuO2@COF-SNO prepared in Example 1 of the present invention;

[0021] Figure 5 Electron paramagnetic resonance diagram of CuO2@COF-SNO prepared in Example 1 of the present invention;

[0022] Figure 6 UV absorption spectra of solutions containing methylene blue with different concentrations of CuO2@COF-SNO prepared in Example 1 of the present invention under acidic conditions;

[0023] Figure 7 NO release curve of CuO2@COF-SNO prepared in Example 1 of the present invention under acidic conditions. Detailed implementation manners

[0024] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0025] In one embodiment of the present invention, a nitric oxide-delivery and copper peroxide-doped nano-covalent organic framework CuO2@COF-SNO is provided, and the covalent organic framework is a Schiff base-type covalent organic framework formed by connecting 1,3,5-tris(4-aminophenyl)benzene and 2,5-diallyloxy terephthalaldehyde with carbon-nitrogen double bonds.

[0026] Preferably, the particle size of the nitric oxide-delivery and copper peroxide-doped nano-covalent organic framework CuO2@COF-SNO is less than 200 nm, and it can accumulate at the tumor site through the EPR effect;

[0027] In one embodiment of the present invention, a preparation method of the above-mentioned nitric oxide-delivery and copper peroxide-doped nano-covalent organic framework CuO2@COF-SNO is provided.

[0028] The preparation method includes the following steps:

[0029] (1) Schiff base reaction of 1,3,5-tris(4-aminophenyl)benzene and 2,5-diallyloxy-1,4-terephthalaldehyde to obtain a Schiff base-type covalent organic framework COF connected by carbon-nitrogen double bonds;

[0030] (2) In trifluorotoluene, COF and 1,2-ethanedithiol are reacted at 80-90 °C for 2-3 h to obtain a thiol-modified nano-covalent organic framework COF-SH;

[0031] (3) In a mixed solution of methanol and toluene, COF-SH is nitrated with tert-butyl nitrite to obtain a nano-covalent organic framework COF-SNO loaded with NO;

[0032] (4) In water, COF-SNO and CuCl2·2H2O are stirred for a certain time, then centrifuged. The centrifuged precipitate is dispersed in a mixed solution containing a certain amount of sodium hydroxide and hydrogen peroxide, and stirred for a certain time to obtain CuO2@COF-SNO.

[0033] In one or more embodiments, the molar ratio of 1,3,5-tris(4-aminophenyl)benzene to 2,5-diallyloxyterephthalaldehyde is 1:1.4 - 1.6; this molar ratio can make the reaction more complete and obtain a suitable COF.

[0034] In one or more embodiments, the time for the Schiff base reaction is 10 - 14 h, and the reaction temperature is 20 - 30 °C; under these reaction conditions, the reaction can be more complete and a suitable COF can be obtained.

[0035] In one or more embodiments, the solvent used in the synthesis of COF is acetonitrile.

[0036] In one or more embodiments, glacial acetic acid with a volume ratio of about 1:9 to acetonitrile is added to the mixed solution during the synthesis of COF.

[0037] In one or more embodiments, when COF reacts with 1,2-ethanedithiol, first disperse COF in trifluorotoluene, then add azobisisobutyronitrile, and add 1,2-ethanedithiol under vacuum conditions.

[0038] Preferably, the molar ratio of the 1,2-ethanedithiol to azobisisobutyronitrile is 1:0.1 - 0.3, preferably 1:0.2.

[0039] Preferably, COF and 1,2-ethanedithiol react at 90 °C for 2.5 hours; the inventors found through experiments that if the reaction time is less than 2.5 hours, the reaction often proceeds incompletely, resulting in a small amount of thiol modification.

[0040] In one or more embodiments, the mass ratio of COF to 1,2-ethanedithiol is 1:0.3 - 0.35; when the mass ratio of COF:1,2-ethanedithiol is higher than 1:0.3 - 0.35, the 1,2-ethanedithiol modification is incomplete and the amount of modified thiol is small. When the mass ratio is lower than 1:0.3 - 0.35, the 1,2-ethanedithiol modification reaches saturation, causing waste. Therefore, through experiments, the mass ratio of COF:1,2-ethanedithiol is selected to be 1:0.3 - 0.35.

[0041] In one or more embodiments, when COF-SH reacts with tert-butyl nitrite, first disperse COF-SH in a mixed solution of methanol and toluene, then add tert-butyl nitrite, and react in the dark.

[0042] Preferably, the volume ratio of methanol to toluene is 1:0.2 - 0.3, preferably 1:0.25.

[0043] In one or more embodiments, the mass ratio of COF-SH to tert-butyl nitrite is 1:0.2 - 0.3; when the mass ratio of COF-SH to tert-butyl nitrite is higher than 1:0.2 - 0.3, the nitration of COF-SH is incomplete and the amount of loaded NO is small. When the mass ratio is lower than 1:0.2 - 0.3, the nitration reaches saturation, causing waste. Therefore, through experiments, the mass ratio of COF-SH:tert-butyl nitrite is selected to be 1:0.2 - 0.3.

[0044] In one or more embodiments, in the process of doping CuO₂ with COF-SNO, the mass ratio of COF-SNO to CuCl₂·2H₂O is 1:0.8 - 1. When the mass ratio of COF-SNO to CuCl₂·2H₂O is lower than 1:0.8 - 1, the amount of adsorbed copper ions is small. When the mass ratio of COF-SNO to CuCl₂·2H₂O is higher than 1:0.8 - 1, the adsorption amount reaches saturation, causing waste. Therefore, through experiments, the mass ratio of COF-SNO to CuCl₂·2H₂O is selected to be 1:0.8 - 1.

[0045] Preferably, stir at room temperature for 20 - 40 min, and more preferably stir for 30 min.

[0046] In one or more embodiments, in the process of doping CuO₂ with COF-SNO, the mass ratio of COF-SNO to NaOH is 1:0.2 - 0.3, and the mass ratio of COF-SNO to H₂O₂ is 1:0.03 - 0.06. Through experiments, the mass ratio of COF-SNO to NaOH is selected to be 1:0.25, and the mass ratio of COF-SNO to H₂O₂ is selected to be 1:0.02.

[0047] Preferably, stir at room temperature for 10 - 20 min, and more preferably stir for 20 min.

[0048] In one embodiment of the present invention, there is provided the use of the above-mentioned copper peroxide-doped nano-covalent organic framework CuO₂@COF-SNO for delivering nitric oxide in the preparation of an antitumor agent.

[0049] The present invention will be further explained and illustrated below with specific examples.

[0050] Example 1

[0051] (1) Synthesis of COF: 22.140 mg (0.0620 mmol) of 1,3,5-tris(4-aminophenyl) was dissolved in 25 mL of acetonitrile, and 21.688 mg (0.0930 mmol) of 2,5-diallyloxyterephthalaldehyde was added. Then, 2.7 mL of glacial acetic acid was added, and the mixture was stirred at 25 °C for 12 h to obtain a nano-covalent organic framework (COF) with alkene bonds, as Figure 1 shown in a.

[0052] (2) Add 9 mg of COF to a 10 mL round-bottom flask, disperse it in 2 mL of trifluorotoluene, add 1 mg (0.00609 mmol) of azobisisobutyronitrile under vacuum and mix well, then add 2.54 μL of 1,2-ethanedithiol, and stir at 90 °C for 2.5 h.

[0053] (3) Centrifuge and wash thoroughly with ethanol to remove unreacted 1,2-ethanedithiol to obtain COF-SH, as Figure 1 shown in b. Disperse 9 mg of COF-SH in a mixed solution of 4 mL of methanol and 1 mL of toluene, add 3 μL of tert-butyl nitrite, and react in the dark for 24 h.

[0054] (4) Centrifuge and wash several times with methanol and ethanol to obtain COF-SNO, as Figure 1 shown in c. Take 9 mg of COF-SNO and disperse it in water, add 8 mg of CuCl2·2H2O, stir for 30 minutes and then centrifuge, disperse it in a solution containing 2 mg of NaOH in 5 mL, and add 50 μL of 30% H2O2 and stir for 20 minutes.

[0055] (5) Centrifuge and wash several times with water to obtain CuO2@COF-SNO, as Figure 1 shown in c.

[0056] (6) Perform low-magnification transmission electron microscopy, X-ray powder diffraction, ultraviolet-visible absorption, and infrared spectroscopy measurements on the COF, COF-SNO, and CuO2@COF-SNO prepared in Example 1: The low-magnification transmission electron microscopy images of COF, COF-SNO, and CuO2@COF-SNO are as Figure 1 shown. The size of COF hardly changes before and after modification; the X-ray powder diffraction is as Figure 2 shown. It can be seen that the diffraction peak of COF is around 2 degrees, and loading NO and doping cupric peroxide do not change the crystalline structure of the COF material; the ultraviolet-visible absorption of COF, COF-SNO, and CuO2@COF-SNO is as Figure 3 shown. The main absorption peak of COF does not change after modification, and CuO2@COF-SNO has better absorption after 500 nm wavelength; the infrared spectra of COF, COF-SNO, and CuO2@COF-SNO are as Figure 4As shown, the infrared absorption peak changes significantly after COF modification.

[0057] (7) The ESR spectrum of detecting ROS in the aqueous solution of CuO2@COF-SNO prepared in Example 1 in the presence of DMPO is as follows: Figure 5 As shown, it has a four-line characteristic peak of 1:2:2:1, indicating that CuO2@COF-SNO can generate a large amount of hydroxyl radicals by catalyzing the self-supplied H2O2.

[0058] (8) The ultraviolet absorption of the methylene blue solution of CuO2@COF-SNO prepared in Example 1 was carried out to evaluate its ability to generate hydroxyl radicals. The ultraviolet absorption of the solutions treated with different concentrations of CuO2@COF-SNO is as Figure 6 shown. It can be seen that CuO2@COF-SNO has good reactive oxygen species generation ability and shows concentration dependence.

[0059] (9) Under acidic conditions, the NO release of CuO2@COF-SNO prepared in Example 1 was detected using a NO detection kit, as Figure 7 shown.

[0060] Example 2

[0061] (1) Synthesize COF: 44.280 mg (0.124 mmol) of 1,3,5-tris(4-aminophenyl)benzene and 43.336 mg (0.186 mmol) of 2,5-diallyloxyterephthalaldehyde were dissolved in 50 mL of acetonitrile, and 5.4 mL of glacial acetic acid was added. The reaction was stirred at 25 °C for 12 h to obtain a nano-covalent organic framework (COF) with olefin bonds.

[0062] (2) Add 9 mg of COF to a 10 mL round-bottom flask, disperse it with 2 mL of trifluorotoluene, add 1 mg (0.00609 mmol) of azobisisobutyronitrile and mix well under vacuum conditions, add 2.54 μL of 1,2-ethanedithiol, and stir the reaction at 90 °C for 2.5 hours.

[0063] (3) Centrifuge and wash the unreacted 1,2-ethanedithiol thoroughly with ethanol to obtain COF-SH, as Figure 1 shown in b. Disperse 9 mg of COF-SH in a mixed solution of 4 mL of methanol and 1 mL of toluene, add 3 μL of tert-butyl nitrite, and react in the dark for 24 hours.

[0064] (4) Centrifuge and wash several times with methanol and ethanol to obtain COF-SNO. Take 9 mg of COF-SNO and disperse it in water, add 8 mg of CuCl2·2H2O, stir for 30 minutes and centrifuge, disperse it in a solution containing 2 mg of NaOH in 5 mL, and add 50 μL of 30% H2O2 and stir for 20 minutes.

[0065] (5) Centrifuge, and after washing several times with water, CuO2@COF-SNO is obtained.

[0066] Example 3

[0067] (1) Synthesize COF: Dissolve 66.420 mg (0.186 mmol) of 1,3,5-tris(4-aminophenyl)benzene and 65.004 mg (0.279 mmol) of 2,5-diallyloxyterephthalaldehyde in 75 mL of acetonitrile, add 8.1 mL of glacial acetic acid, and stir and react at 25 °C for 12 h to obtain a nano-covalent organic framework (COF) with olefin bonds.

[0068] (2) Add 9 mg of COF to a 10 mL round-bottom flask, disperse it with 2 mL of trifluorotoluene, add 1 mg (0.00609 mmol) of azobisisobutyronitrile and mix well under vacuum conditions, add 2.54 μL of 1,2-ethanedithiol, and stir and react at 90 °C for 2.5 hours.

[0069] (3) Centrifuge, and wash away the unreacted 1,2-ethanedithiol with ethanol sufficiently to obtain COF-SH, as shown in Figure 1 b. Disperse 9 mg of COF-SH in a mixed solution of 4 mL of methanol and 1 mL of toluene, add 3 μL of tert-butyl nitrite, and react in the dark for 24 hours.

[0070] (4) Centrifuge, wash several times with methanol and ethanol to obtain COF-SNO. Take 9 mg of COF-SNO and disperse it in water, add 8 mg of CuCl2·2H2O, stir for 30 minutes and centrifuge, disperse it in a solution containing 2 mg of NaOH in 5 mL, and add 50 μL of 30% H2O2 and stir for 20 minutes.

[0071] (5) Centrifuge, and after washing several times with water, CuO2@COF-SNO is obtained.

[0072] Comparative Example 1

[0073] The difference from Example 1 is that when reacting COF with 1,2-ethanedithiol, azobisisobutyronitrile is not added as a catalyst, and other preparation steps are the same as those in Example 1. It is found through experiments that the reaction between COF and 1,2-ethanedithiol cannot proceed.

[0074] Comparative Example 2

[0075] The difference from Example 1 is that when reacting COF with 1,2-ethanedithiol, the reaction time is 1 hour, and other preparation steps are the same as those in Example 1. The effect of measuring the number of modified thiol groups is less than that of COF-SNO obtained at a reaction time of 2.5 hours in Example 1.

[0076] Comparative Example 3

[0077] The difference from Example 1 is that when the reaction of COF and tert-butyl nitrite was carried out, the reaction time was 4 hours, and the other preparation steps were the same as those in Example 1. The effect of NO generation was measured, and the result was inferior to that of COF-SNO obtained with a reaction time of 24 hours in Example 1.

[0078] Comparative Example 4

[0079] The difference from Example 1 is that when the reaction of COF and tert-butyl nitrite was carried out, the reaction time was 8 hours, and the other preparation steps were the same as those in Example 1. The effect of NO generation was measured, and the result was inferior to that of COF-SNO obtained with a reaction time of 24 hours in Example 1.

[0080] Comparative Example 5

[0081] The difference from Example 1 is that when the reaction of COF and CuCl₂·2H₂O was carried out, the reaction time was 5 minutes, and the other preparation steps were the same as those in Example 1. The effect of reactive oxygen species generation was measured, and the result was inferior to that of CuO₂@COF-SNO obtained with a reaction time of 30 minutes in Example 1.

[0082] Comparative Example 6

[0083] The difference from Example 1 is that when the reaction of COF and CuCl₂·2H₂O was carried out, the reaction time was 15 minutes, and the other preparation steps were the same as those in Example 1. The effect of reactive oxygen species generation was measured, and the result was inferior to that of CuO₂@COF-SNO obtained with a reaction time of 30 minutes in Example 1.

[0084] It can be seen from the above examples and comparative examples that when modifying the thiol group on COF, the catalyst is the key to promoting the reaction. When the reaction time is less than 2.5 hours, the reaction is incomplete. When measuring the number of thiol group modifications, the result is inferior to that of COF-SH obtained with a reaction time of 2.5 hours in Example 1; when reacting with tert-butyl nitrite, when the reaction time is less than 24 hours, the reaction is incomplete and the NO loading is less, and the result is inferior to that of COF-SNO obtained with a reaction time of 24 hours in Example 1.

[0085] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A nano-covalent organic framework CuO₂@COF-SNO that delivers NO and is doped with cupric peroxide, characterized in that, Among them, the nano-covalent organic framework COF-SNO is obtained by reacting the double bonds on the covalent organic framework COF with mercapto groups and then reacting with tert-butyl nitrite. The covalent organic framework COF is a Schiff base type covalent organic framework formed by connecting 1,3,5-tris(4-aminophenyl)benzene and 2,5-diallyloxyterephthalaldehyde with carbon-nitrogen double bonds; The preparation method of the nano-covalent organic framework CuO2@COF-SNO that delivers NO and is doped with cupric peroxide includes the following steps: (1) 1,3,5-tris(4-aminophenyl)benzene and 2,5-diallyloxy-1,4-terephthalaldehyde undergo a Schiff base reaction to obtain a Schiff base type covalent organic framework COF connected by carbon-nitrogen double bonds; (2) In trifluorotoluene, COF and 1,2-ethanedithiol react at 80-90 °C for 2-3 h to obtain a mercapto-modified nano-covalent organic framework COF-SH; the catalyst is azobisisobutyronitrile; (3) In a mixed solution of methanol and toluene, COF-SH is nitrated by tert-butyl nitrite to obtain a nano-covalent organic framework COF-SNO loaded with NO; (4) In water, after COF-SNO and CuCl2·2H2O are stirred at room temperature for 20-40 min, centrifuged, and the centrifuged precipitate is dispersed in a mixed solution containing a certain amount of sodium hydroxide and hydrogen peroxide, the mass ratio of COF-SNO to NaOH is 1:0.2-0.3, and the mass ratio of COF-SNO to H2O2 is 1:0.03-0.

06. Stir at room temperature for 10-20 min to obtain CuO2@COF-SNO; The mass ratio of COF to 1,2-ethanedithiol is 1:0.3-0.35; COF and 1,2-ethanedithiol react at 90 °C for 2.5 hours; The mass ratio of COF-SH to tert-butyl nitrite is 1:0.2-0.3; The mass ratio of COF-SNO to CuCl2·2H2O is 1:0.8-1.

2. The nano-covalent organic framework CuO2@COF-SNO for delivering NO and doped with cupric peroxide as claimed in claim 1, wherein, The particle size of the nano-covalent organic framework that delivers nitric oxide and is doped with cupric peroxide is less than 200 nm.

3. The nano-covalent organic framework CuO2@COF-SNO for delivering NO and doped with cupric peroxide as claimed in claim 1, wherein, The mass ratio of COF to NO is 1:0.01-0.04, and the mass ratio of COF to CuO2 is 1:0.008-0.

015.

4. A method for preparing a nano-covalent organic framework CuO₂@COF-SNO that delivers NO and is doped with cupric peroxide as described in any one of claims 1 to 3, characterized in that, The preparation method includes the following steps: (1) 1,3,5-tris(4-aminophenyl)benzene and 2,5-diallyloxy-1,4-terephthalaldehyde undergo a Schiff base reaction to obtain a Schiff base type covalent organic framework COF connected by carbon-nitrogen double bonds; (2) In trifluorotoluene, COF and 1,2-ethanedithiol react at 80-90 °C for 2-3 h to obtain a mercapto-modified nano-covalent organic framework COF-SH; (3) In a mixed solution of methanol and toluene, COF-SH is nitrated by tert-butyl nitrite to obtain a nano-covalent organic framework COF-SNO loaded with NO; (4) In water, after COF-SNO and CuCl2·2H2O are stirred for a certain time, centrifuged, and the centrifuged precipitate is dispersed in a mixed solution containing a certain amount of sodium hydroxide and hydrogen peroxide, and stirred for a certain time to obtain CuO2@COF-SNO.

5. The preparation method according to claim 4, characterized in that, The molar ratio of 1,3,5-tris(4-aminophenyl)benzene to 2,5-diallyloxyterephthalaldehyde is 1:1.4 to 1.

6.

6. The preparation method according to claim 4, wherein, The time for the Schiff base reaction is 10 to 14 h, and the reaction temperature is 20 to 30 °C; Alternatively, the solvent used in the Schiff base reaction process is acetonitrile; Alternatively, glacial acetic acid is added to the mixed solution during the Schiff base reaction process.

7. The preparation method according to claim 4, characterized in that, When COF reacts with 1,2-ethanedithiol, first disperse COF in trifluorotoluene, add 1,2-ethanedithiol, and add the catalyst azobisisobutyronitrile under vacuum conditions.

8. The preparation method according to claim 7, wherein The molar ratio of the 1,2-ethanedithiol to azobisisobutyronitrile is 1:0.

2.

9. The preparation method according to claim 4, wherein When COF-SH reacts with tert-butyl nitrite, disperse COF-SH with a mixed solution of methanol and toluene, and then add tert-butyl nitrite for a light-shielded reaction.

10. The preparation method according to claim 9, characterized in that, The volume ratio of methanol to toluene is 1:0.2 to 0.

3.

11. The preparation method according to claim 9, characterized in that, The volume ratio of methanol to toluene is 1:0.

25.

12. The preparation method according to claim 4, characterized in that, When stirring COF-SNO with CuCl2·2H2O, the stirring time at room temperature is 20 to 40 min; During the process of dispersing the centrifuged precipitate in a mixed solution containing a certain amount of sodium hydroxide and hydrogen peroxide and stirring, the mass ratio of COF-SNO to NaOH is 1:0.2 to 0.3, the mass ratio of COF-SNO to H2O2 is 1:0.03 to 0.06, and the stirring time at room temperature is 10 to 20 min.

13. The preparation method according to claim 12, wherein When stirring COF-SNO with CuCl2·2H2O, stir for 30 min.

14. The preparation method according to claim 12, characterized in that, During the process of dispersing the centrifuged precipitate in a mixed solution containing a certain amount of sodium hydroxide and hydrogen peroxide and stirring, the stirring time at room temperature is 20 min.

15. Use of a nano-covalent organic framework CuO2@COF-SNO that delivers NO and is doped with cupric peroxide as described in any one of claims 1-3 in the preparation of a tumor treatment preparation.

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