Preparation method and application of disulfide bond-containing vanadium dioxide nanoparticles

Abstract

The invention discloses a preparation method and application of disulfide bond-containing vanadium dioxide nanoparticles, and the preparation method comprises the following steps: respectively mixing polyvinylpyrrolidone and VOSO4 with ultrapure water, and then mixing the polyvinylpyrrolidone and the VOSO4; adding a solution of 3, 3-dithiodipropionic acid and 2-aminoterephthalic acid into the mixed solution, and carrying out a reaction; then adding ethylene glycol and triethylamine; after stirring, carrying out hydrothermal reaction to obtain VS NPs; adding the VS NPs into the BSA, and stirring to obtain the VSB NPs. The prepared nanoparticles can consume glutathione and generate active oxygen at the same time, the biocompatibility is improved through BSA wrapping, and the nanoparticles have excellent photo-thermal performance and can break the redox steady state of tumor cells bidirectionally, amplify oxidative stress and trigger ferroptosis. Degradation products of the nanoparticles can trigger pyroptosis of tumor cells, photo-thermal enhanced multi-mode combined treatment of ferroptosis and pyroptosis of the tumor cells is achieved, and tumor growth is effectively inhibited.

Description

Technical Field

[0001] The invention belongs to the technical field of nano-medicine, and specifically relates to a preparation method and application of vanadium dioxide nanoparticles containing disulfide bonds. Background Art

[0002] Cancer poses a major challenge to global public health. Due to the complexity, diversity and heterogeneity of tumors themselves, the current clinical treatment effect has not yet fully achieved the expected goal. At present, a variety of new tumor treatment methods have been developed based on nanomaterials. Among them, chemodynamic therapy (CDT) is favored because it can use endogenous hydrogen peroxide (H2O2) to produce Fenton or Fenton-like reactions to produce more toxic hydroxyl radicals (·OH). However, glutathione (GSH) overexpressed in the tumor microenvironment (TME) as an important antioxidant maintains redox homeostasis by scavenging ROS, which greatly limits the efficiency of the CDT treatment model. In view of this, many researchers use nanocarriers to provide functional molecules to directly consume GSH or use metal multivalent states to induce oxidative stress, and synthesize complexes FP@MC and CuSiO3@Au-Pd nanoparticles to improve the efficiency of CDT treatment. However, only using the multivalent state of metal ions will inevitably lead to low catalytic efficiency and poor catalytic kinetics, and the layer-by-layer assembly steps of disulfide bond-containing nanocarrier complexes are cumbersome. Therefore, the current challenge is how to synthesize nanoparticles with the function of consuming GSH and generating ROS simultaneously in one step through a simple chemical method. In addition, due to the tumor-specific microenvironment, single therapy is often ineffective. Therefore, the introduction of other treatments for combined treatment may produce synergistic effects, which is expected to improve the anti-cancer efficiency.

[0003] Photothermal therapy (PTT) is a minimally invasive treatment method that converts photon energy into thermal energy. It has become a promising tumor intervention option due to its special intrinsic properties, such as strong controllability, non-invasiveness, and minimal side effects. Near-infrared (NIR) light has minimal absorption and scattering of tissue components (including skin, blood, and biomolecules), and therefore, can penetrate deep tissues. Traditional organic molecular photothermal agents are limited in cancer photothermal therapy due to problems such as photobleaching, low absorption cross-section, and poor near-infrared photothermal conversion efficiency. In contrast, metal-based nanomaterials have superior properties due to their high molar extinction coefficient, resistance to photodegradation, and strong near-infrared absorption. In particular, near-infrared II (NIR-II, 1000-1350nm) photothermal therapy has developed rapidly in recent years, and the tissue penetration depth is higher than that of near-infrared I (NIR-I, 650-950nm), which has stimulated researchers' interest in exploring metal-based nano NIR II photothermal materials. Summary of the invention

[0004] Purpose of the invention: In view of the problems existing in the prior art, the present invention provides a method for preparing vanadium dioxide nanoparticles containing disulfide bonds. The vanadium dioxide nanoparticles containing disulfide bonds prepared by the present invention can consume GSH and generate ROS at the same time, amplify oxidative stress, and trigger ferroptosis of tumor cells, which effectively solves the problem that some nanoparticles in the prior art kill tumors by only generating ROS but do not have the ability to consume GSH, which greatly weakens the ROS treatment strategy; some nanoparticles first react with H2O2 to obtain high-valent metal ions, and then use the high-valent state to consume GSH to promote the generation of ROS, but this greatly reduces the reaction efficiency.

[0005] The invention provides the vanadium dioxide nanoparticles containing disulfide bonds and applications thereof.

[0006] Technical solution: In order to achieve the above-mentioned purpose, the method for preparing vanadium dioxide nanoparticles containing disulfide bonds of the present invention comprises the following steps:

[0007] (1) Dissolve polyvinyl pyrrolidone (PVP) in ultrapure water and stir vigorously;

[0008] (2) Mix VOSO4 with ultrapure water and disperse by ultrasonication;

[0009] (3) transferring the VOSO4 aqueous solution to the PVP solution for reaction;

[0010] (4) dissolving 3,3-dithiodipropionic acid and 2-aminoterephthalic acid in organic solvents respectively, and then adding them into the mixed solution of step (3) to react;

[0011] (5) adding ethylene glycol and triethylamine to the solution after the reaction in step (4); stirring and then performing a hydrothermal reaction, collecting the solution, and washing by centrifugation to obtain VS NPs;

[0012] (6) Dissolve VS NPs in buffer, add BSA and stir to obtain VSB NPs.

[0013] Among them, the feeding ratio of PVP in step (1) and VOSO4 in step (2) is 1-20:1-4.

[0014] Preferably, the feed mass ratio of PVP to VOSO4 is 5:2.

[0015] Wherein, in step (3), the VOSO4 aqueous solution is transferred to the PVP solution and stirred at room temperature for 1-2 hours.

[0016] Wherein, in step (4), the mass ratio of 3,3-dithiodipropionic acid to diaminoterephthalic acid is 1-5:2-10.

[0017] Preferably, the mass ratio of the 3,3-dithiodipropionic acid to diaminoterephthalic acid is 5:2.

[0018] Wherein, the temperature of the hydrothermal reaction in step (5) is 120°C to 180°C, and the time is 6h to 48h.

[0019] In step (6), VS NPs are dissolved in PBS, a Tris-HCl solution of BSA is added, and the mixture is stirred at 50-60° C. for 1-2 h to obtain VSB NPs.

[0020] Preferably, the method for preparing the nanoparticles is carried out according to the following steps:

[0021] (1) Dissolve 0.05 g to 1.0 g of polyvinyl pyrrolidone (PVP) in 10 mL of ultrapure water and stir vigorously.

[0022] (2) Mix 0.0978 g to 0.384 g VOSO4 with ultrapure water and disperse by ultrasonic for a period of time;

[0023] (3) transferring the VOSO4 aqueous solution to the PVP solution to react for a period of time;

[0024] (4) Take 0.256 g of 3,3-dithiodipropionic acid and dissolve it in 5 mL of N,N-dimethylformamide (DMF), take 0.1 g to 0.5 g of 2-aminoterephthalic acid and dissolve it in 2 mL of DMF, and then add them to the mixed solution of the above (3).

[0025] (5) After a period of time, quickly add 0-6 mL of ethylene glycol and 0.1-1 mL of triethylamine to the solution in (4).

[0026] (6) After stirring at room temperature for 2 h, the solution was transferred to a high-pressure polytetrafluoroethylene reactor and reacted for a certain period of time. The solution was collected and washed by centrifugation to obtain VS NPs.

[0027] (7) Weigh 10 mg of VS NPs and dissolve it in 10 mL of PBS. Weigh 100 mg of BSA and dissolve it in Tris-HCl (pH 8.5). Stir at 50 °C for 2 h to obtain VSB NPs.

[0028] Furthermore, the optimal ratio of PVP to VOSO4 is 5:2; the optimal ratio of 3,3-dithiodipropionic acid to 2-aminoterephthalic acid is 5:2; the optimal amount of ethylene glycol is 3 mL, and the optimal amount of triethylamine is 300 μL.

[0029] Furthermore, the prepared VS NPs were washed three times with ethanol: water = 1:1 at a speed of 8000 rpm. The prepared VSB NPs were washed three times with ultrapure water at a speed of 10000 rpm.

[0030] The vanadium dioxide nanoparticles containing disulfide bonds are prepared by the preparation method of the invention.

[0031] Wherein, the VS NPs and VBS NPs are both vanadium dioxide nanoparticles containing disulfide bonds, and the two have the same function. In order to improve biocompatibility for anti-tumor effects, BSA is coated on the surface of VS NPs to obtain VSB NPs; VSB NPs are used for tumor treatment.

[0032] The invention relates to the use of vanadium dioxide nanoparticles (VSB NPs) containing disulfide bonds in the preparation of anti-tumor agents or drugs.

[0033] Among them, the vanadium dioxide nanoparticles (VSB NPs) containing disulfide bonds can effectively inhibit tumor growth through multi-modal combined treatment of photothermal enhanced tumor cell ferroptosis and pyroptosis, have obvious anti-tumor effects, and are used in the preparation of anti-tumor agents or drugs.

[0034] The nanoparticles prepared by the present invention are nanoparticles that can simultaneously consume glutathione (GSH) and generate reactive oxygen species (ROS). The nanoparticles are synthesized by a simple one-pot hydrothermal method, and the VS NPs with optimal performance, morphology and size are obtained by regulating the reaction temperature, reaction time, type of vanadium source, amount of PVP, type of solvent, solvent ratio and ratio of ligand. The biocompatibility is improved by encapsulation with bovine serum albumin (BSA). The nanoparticles have a hydrangea structure, a size of about 130nm, and excellent photothermal performance. The nanoparticles can bidirectionally break the redox homeostasis of tumor cells, amplify oxidative stress, and trigger ferroptosis. The degradation products of the nanoparticles themselves can trigger pyroptosis of tumor cells. The nanoparticles can achieve multi-modal combined treatment of photothermally enhanced ferroptosis and pyroptosis of tumor cells to inhibit tumor growth.

[0035] The present invention synthesizes vanadium dioxide nanoparticles with photothermal properties and containing disulfide bonds by a simple one-step hydrothermal method. The nanoparticles use 3,3-dithiodipropionic acid as a ligand to introduce disulfide bonds, and use 2-aminoterephthalic acid as a metal chelator to integrate the functions of consuming GSH and generating ROS in one nanoparticle. The synthesis method avoids the cumbersome steps of layer-by-layer assembly of disulfide bond-containing carriers and complexes, and achieves multiple functions in one step. The biocompatibility is improved by BSA encapsulation to obtain VSB NPs. It has been experimentally confirmed that VSB NPs have good biocompatibility, can reduce GSH content and increase ROS levels in a TME-responsive manner, and effectively inhibit tumor growth through the combined treatment of PTT-enhanced ferroptosis and pyroptosis of tumor cells. The materials prepared by the present invention highlight the potential biological effects of vanadium in cancer treatment and provide new materials and methods for its application in anti-tumor strategies.

[0036] Compared with the traditional vanadium dioxide preparation scheme, the vanadium dioxide nanoparticles containing disulfide bonds prepared by the present invention have the following advantages in the synthesis process: the reaction temperature is reduced, the reaction time is shortened, and there is no need to calcine at 500°C in a tube furnace for a period of time, which greatly reduces the cost and simplifies the synthesis process. Advantages of the product: The size of the obtained nanoparticles is nanometer-level and less than 200nm, which is more conducive to biological applications. The present invention provides a nanoparticle with small size and photothermal properties, which can simultaneously consume GSH and generate ROS in the tumor microenvironment to amplify oxidative stress and induce ferroptosis of tumor cells. The possible anti-tumor mechanism of its degradation products is explored.

[0037] The use of ROS for tumor treatment in the present invention is an emerging anti-cancer strategy, but the overexpressed GSH in tumor cells will remove ROS to maintain the redox balance of tumor cells, which is convenient for tumor growth. The development of a material that can consume GSH while generating ROS will greatly improve the efficiency of tumor treatment. At present, there are also many nanocomposites that assemble drugs or functional particles that can consume GSH and generate ROS to achieve this purpose, but the process is cumbersome and inefficient, and even brings toxic side effects. Based on this, the present invention designs and prepares vanadium dioxide nanoparticles containing disulfide bonds by a simple one-step hydrothermal method, using the chelation of 3,3-dithiodipropionic acid and vanadate, and with the help of PVP surfactant, a one-step reaction at a certain temperature and time can be obtained. Among them, the carbonyl group on the PVP ring effectively protects the disulfide bond and tetravalent vanadium from oxidation on the one hand, and on the other hand, it is surrounded by the crystal surface because it combines with water molecules to form hydrogen bonds, allowing the crystal to grow in a certain morphology; in addition, the hydrophobic carbon chains in PVP repel each other due to the steric hindrance effect, preventing the nanoparticles from agglomerating, thereby improving the dispersibility of the nanoparticles.

[0038] The whole reaction steps of the present invention are simple, the conditions are mild, and the raw materials are cheap and easily available. More importantly, vanadates are not selective and are difficult to reach the tumor site, so the present invention designs the form of synthesized nanoparticles to facilitate transportation to the tumor site and reduce toxic side effects on other tissues.

[0039] The present invention applies VSB NPs to tumor treatment, which can simultaneously consume GSH and generate ROS (·OH and 1 O2), that is, consuming GSH makes ROS relatively more, and nanoparticles can generate ROS, so the ROS level is further increased, so that ROS is significantly increased, and the efficiency of tumor treatment is improved. The nanoparticles prepared by the present invention have a simple structure but not simple functions, and provide a promising nano-platform based on therapeutic nano-agents for multi-modal combined treatment of cancer. The vanadium dioxide prepared by the present invention contains disulfide bonds, and does not require high temperature annealing, and the conditions are mild.

[0040] The VS NPs prepared in the present invention consume GSH through disulfide bonds instead of metallic vanadium sources because the valence of vanadium does not change, which can be seen from Fig.11 This provides a basis for the simultaneous consumption of GSH and production of ROS in tumor cells. Fig.14 It can be seen that the enhancement of ROS in tumor cells may even lead to ferroptosis of tumor cells, greatly improving the efficiency of tumor treatment. Fig.15 It can be proved that the degradation product of nanoparticles, high-valent vanadate, can inhibit the Na + / K + The VSB NPs prepared by the present invention also have a photothermal effect, with a photothermal conversion efficiency of up to 50%, which can effectively ablate tumor cells. Fig.13 and Fig.16 The effect of killing tumor cells can also be seen in the results, indicating that photothermal synergy enhances tumor cell ferroptosis and pyroptosis, achieving multimodal synergistic treatment of tumors.

[0041] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0042] The present invention provides a simple one-step hydrothermal method for synthesizing VS NPs, which are coated with BSA to improve biocompatibility and obtain VSB NPs. The vanadium dioxide nanoparticles (VSB NPs) containing disulfide bonds prepared by the present invention can be used in tumor treatment to simultaneously consume GSH and generate ROS, significantly increase ROS, and improve tumor treatment efficiency; at the same time, the VSB NPs prepared with better biocompatibility also have a photothermal effect, which can effectively ablate tumor cells, and photothermal synergistically enhances ferroptosis and pyroptosis of tumor cells, realizing multi-modal synergistic treatment of tumors.

[0043] In the anti-tumor mechanism, VSB NPs consume endogenous GSH (weakening the ability to scavenge ROS) and at the same time 4+ Through the Fenton-like reaction, ·OH is generated, bidirectionally breaking the redox homeostasis, thereby enhancing CDT-mediated tumor therapy. In vitro and in vivo experiments have confirmed that VSB NPs have good biocompatibility, can reduce GSH content and increase ROS levels in a TME-responsive manner, and effectively inhibit tumor growth through the combined treatment of PTT-enhanced tumor cell ferroptosis and pyroptosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A in the middle is the transmission electron microscopy image of VS NPs; Figure 1 B is a high-resolution transmission electron microscopy image of VS NPs; Figure 1 Middle C is the electron microscope image of the selected area after Fourier processing correction; Figure 1 D in the figure is the XRD pattern of VS NPs.

[0045] Figure 2 Transmission electron microscopy images of VS NPs synthesized with different PVP dosages. The amounts of PVP from Figures AE are 0.05g, 0.1g, 0.2g, 0.5g, and 1.0g, respectively.

[0046] Figure 3 Transmission electron microscopy images of VS NPs synthesized at different reaction times. The reaction times from Figures AE are 6h, 8h, 12h, 24h, and 48h, respectively.

[0047] Figure 4 Transmission electron microscopy images of VS NPs synthesized with different 2-aminoterephthalic acid feeds. The amounts of 2-aminoterephthalic acid in Figures AC are 0.5 g, 0.3 g, and 0.1 g, respectively.

[0048] Figure 5 A in the middle is the transmission electron microscopy image of VS NPs synthesized with different types of vanadium sources; Figure 5 B is the transmission electron microscopy image of VS NPs synthesized with VOSO4 feed amounts of 0.0978 g, 0.196 g, and 0.384 g, respectively.

[0049] Figure 6 Transmission electron microscopy images of VS NPs synthesized at different reaction temperatures. The reaction temperatures in Figures AD are 120℃, 150℃, 180℃, and 240℃, respectively.

[0050] Figure 7Transmission electron micrographs of VS NPs synthesized with different solvent ratios and NaOH solution. The ratios of water, N,N-dimethylformamide (DMF) and ethylene glycol are 20:7:3, 6:21:3 and 6:7:17 from A to C. D shows the water in A was replaced with 0.01M NaOH solution.

[0051] Figure 8 Transmission electron microscopy images of VS NPs synthesized by adding different amounts of ethylene glycol. The amounts of ethylene glycol in Figures AC are 0 mL, 3 mL, and 6 mL respectively.

[0052] Fig. 9 A in the figure is the transmission electron microscopy image of VSB NPs. Fig. 9 Medium B and Fig. 9 C in the middle are the UV-visible-near-infrared absorption spectra and Fourier transform infrared spectra of VS NPs, VSB NPs, and BSA, respectively.

[0053] Fig.10 A in 10 and B in 10 are the photothermal conversion diagram and photothermal cycle diagram of VSB NPs, respectively.

[0054] Fig.11 A in the figure shows the kinetic Raman spectra of VS NPs in aqueous medium and VS NPs under the action of GSH. Fig.11 B in the figure is the XPS spectrum of VS (V 2p) after different treatments. Fig.11 Figure C shows the release curve of V from VSB NPs in GSH buffer solutions at pH 7.4, pH 5.5, and pH 5.5. The data are shown as mean ± standard deviation (n = 3). Fig.11 D is the UV-visible absorption spectrum of the time-dependent consumption of GSH by VSB NPs.

[0055] Fig.12 A in the middle is the UV-visible absorption spectrum of the catalytic oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by VSB NPs under different conditions; Fig.12 B is produced under different conditions 1 UV-visible absorption spectrum of O2 on DPBF degradation.

[0056] Fig.13 Middle A and Fig.13 (B) shows the cell viability of Raw 264.7 and L02 cells after treatment with VSB NPs, respectively. Fig.13 Center C shows the survival rate of MCF-7 cells treated with VSB NP and VSB NP+L.

[0057] Fig.14 Middle A shows the production of ROS in MCF-7 cells with different treatments (scale bar = 100 μm); Fig.14 B: The changes of LPO in MCF-7 cells were detected using C11-BODIPY581 / 591 probe after different treatments (scale bar = 20 μm).

[0058] Fig.15 A in the middle is the Na of membrane after different treatments + / K + ATPase activity assay (n=3); Fig.15 B shows the intracellular K after different treatments + The change of concentration (scale bar = 20 μm); Fig.15 Middle C is the immunofluorescence image of NLRP3 in MCF-7 cells after different treatments (scale bar = 20 μm).

[0059] Fig.16 Confocal images of MCF-7 cells stained with Calcein AM (green, live cells) and propidium iodide (red, dead cells) after different treatments (scale bar = 100 μm). DETAILED DESCRIPTION

[0060] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0061] The experimental methods described in the examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0062] Example 1

[0063] Preparation of vanadium dioxide nanoparticles containing disulfide bonds:

[0064] (1) Dissolve 0.5 g of polyvinylpyrrolidone (PVP, average molecular weight 1000) in 10 mL of ultrapure water and stir vigorously.

[0065] (2) Mix 0.196 g of VOSO4 with 10 mL of ultrapure water and disperse by ultrasonication.

[0066] (3) The VOSO4 aqueous solution in the above steps (1) and (2) was transferred to the PVP solution mixture and stirred at room temperature for 1 h.

[0067] (4) Take 0.256 g of 3,3-dithiodipropionic acid and dissolve it in 5 mL of N,N-dimethylformamide (DMF), take 0.1 g of 2-aminoterephthalic acid and dissolve it in 2 mL of DMF, then add them to the mixed solution of (3) above (first add 3,3-dithiodipropionic acid, then add 2-aminoterephthalic acid), and react at room temperature for 2 h.

[0068] (5) After 2 h, 3 mL of ethylene glycol and 300 μL of triethylamine were quickly added to the solution in (4).

[0069] (6) After stirring at room temperature for 1 h, the solution was transferred to a high-pressure polytetrafluoroethylene reactor, the reaction temperature was set to 160 °C, the reaction time was set to 24 h, the solution was collected, and the precipitate was washed by centrifugation to obtain a crude product VS NPs; the crude product VS NPs was washed three times with ethanol: water = 1:1 at a rotation speed of 8000 rpm to obtain VS NPs.

[0070] (7) Weigh 10 mg of VS NPs and dissolve it in 10 mL of PBS (pH = 7.4). Weigh 100 mg of BSA and dissolve it in Tris-HCl at pH 8.5. Add the BSA Tris-HCl solution to the PBS solution of VS NPs and stir at 50 °C for 2 h. Collect the solution and wash the precipitate by centrifugation to obtain the crude product VSB NPs. The crude product VSB NPs should be washed three times with ultrapure water at a rotation speed of 10,000 rpm to obtain VSB NPs.

[0071] Example 2

[0072] 1. The VS NPs prepared in Example 1 were characterized by transmission electron microscopy (TEM). The size of the VS NPs was about 130 nm ( Figure 1 A), from TEM, it can be seen that the nanoparticles are evenly dispersed, which is convenient for further biological applications. When the TEM image is magnified to a certain extent, it can be observed that the VS NPs have a ball-like morphology and seem to have mesopores ( Figure 1 B). High-resolution TEM (HRTEM) images show the lattice characteristics of VSNPs, with lattice spacings of 0.22nm, 0.21nm, and 0.25nm ( Figure 1 C), which is consistent with the (121), (220), and (021) crystal planes of VS NPs, confirming the high crystallinity of the nanoparticles. X-ray diffraction (XRD) results show that all diffraction peaks closely match those of VO2 (JCPDS No. 25-1003) cards ( Figure 1 D) confirms the successful synthesis of VO2 nanoparticles. Due to the incorporation of sulfur, the characteristic peaks are slightly shifted to higher angles.

[0073] 2. According to the preparation method of Example 1, the amount of PVP was changed to explore its effect on the morphology and size of VS NPs. Under the same conditions, when the amount of PVP increased from 0.05g to 1.0g, the morphology of the nanoparticles changed from nanosheets to nanospheres, and the size gradually increased ( Figure 2 ). Finally, 0.5g PVP was determined to be the optimal amount.

[0074] 3. According to the preparation method of Example 1, the reaction temperature was fixed at 160°C, and the reaction time was adjusted to 6h, 8h, 12h, 24h, and 48h, respectively, to observe the nucleation and growth of nanoparticles. The results showed that when the reaction time was 6h, the nanoparticles had nucleated and appeared as small spheres ( Figure 3 A); As the reaction time was extended to 24 h, the nanoparticles showed a growth trend and their size gradually increased ( Figure 3 BD); when the reaction time was 48 h, the nanoparticles did not grow further and the morphology did not change significantly ( Figure 3 E). The above results show that when the reaction time is between 6h and 24h, the nanoparticles are mainly growing; when it is between 24h and 48h, the nanoparticles no longer grow and are mainly stable in structure. Therefore, 24h is selected as the optimal reaction time.

[0075] 4. According to the preparation method of Example 1, in the initial stage of synthesizing VS NPs, the vanadium source was VOSO4 (0.196 g), and ethylene glycol (EG) and triethylamine (TEA) were not added. The amount of ligand was used as the main research condition. When 0.5 g of 2-aminoterephthalic acid was added, Figure 4 As shown in Figure A, the nanoparticles have various morphologies and uneven sizes, mainly existing in the form of large and thick nanorods and small nanoflowers. When 0.3 g of 2-aminoterephthalic acid is added, no large nanorods are generated, and only nanorods with a size of about 200 nm are aggregated together ( Figure 4 B), and the dispersion was uneven; when 0.1 g of 2-aminoterephthalic acid was added, smaller nanorods appeared and tended to agglomerate into nanostructures ( Figure 4 C). The above experimental results show that 2-aminoterephthalic acid is a key factor affecting the size and morphology of VS NPs. In order to obtain small-sized nanoparticles, the final amount of 2-aminoterephthalic acid used is 0.1 g.

[0076] 5. The type and feed ratio of the metal source of the present invention will also affect the size and morphology of the nanoparticles. First, the effect of different vanadium sources (NH4VO3, VCl3, VOSO4) on the nanoparticles was explored, and VOSO4 was replaced with other vanadium sources according to the method of Example 1. Figure 5As shown in A, when the vanadium source is NH4VO3, the size of the nanoparticles varies from 250nm to 500nm, and there is agglomeration; when the vanadium source is VCl3, the size of the nanoparticles is about 50nm, but the particle structure is loose and may have poor stability. At the same time, VCl3 has not been used in subsequent experiments due to factors such as high price, high volatility, and inconvenient storage. At the same time, the tetravalent vanadium of the present invention is easier to react with hydrogen peroxide to undergo a Fenton-like reaction compared to NH3VO3, which is convenient for tumor treatment. Therefore, subsequent experiments are all conducted using VOSO4 as the vanadium source. Secondly, the effect of the feed ratio of the vanadium source on the nanoparticles was explored, and the amount of VOSO4 added was adjusted from 0.0978g to 0.384g according to the method in Example 1. Figure 5 As shown in Figure B, as the feed ratio of VOSO4 increases, the size of the nanoparticles gradually increases and the structure becomes more compact. These results show that the type of metal source and feed ratio are key factors in synthesizing structurally stable nanoparticles, so 0.196g VOSO4 was selected as the optimal condition for subsequent experimental exploration.

[0077] 6. In the present invention, under the same conditions as in Example 1, the reaction temperature was changed to investigate the nucleation and growth of nanoparticles. When the reaction temperature was 120°C, the product was an orange solid powder that was insoluble in water. Figure 6 As shown in A, the nanoparticles are shaped like lotus flowers, with a size of about 500nm, a loose structure, and a thin flaky edge, indicating that the nanoparticles are mainly grown under this condition; when the reaction temperature is 150℃, nanodots with a size of about 10nm attached to the surface of the flaky structure can be obtained ( Figure 6 B), indicating that the nanoparticles did not receive enough heat to form kinetically stable nanoparticles; when the reaction temperature was 180 °C, the nanoparticles formed uneven nanodots and then aggregated into hollow nanoclusters, indicating that high temperature tended to nucleate nanoparticles, accompanied by the growth of non-dense structures ( Figure 6 C); when the reaction temperature is 240℃, the nanoparticles have irregular morphology but a compact structure ( Figure 6 D), the solution is black, and black solid can be obtained by washing, indicating that increasing the temperature is conducive to the nucleation of nanoparticles, while the agglomeration phenomenon may be detrimental to the further biological application of the particles. Compared with the above reaction temperature, the morphology and size of the nanoparticles obtained at 160°C in Example 1 are more uniform, so the optimal temperature is 160°C.

[0078] 7. The present invention achieves controllable synthesis of nanoparticles by regulating the ratio of solvents. Therefore, the effect of changing the ratio of solvents and the pH of the solution on the size and morphology of the nanoparticles was explored. The amount of each solvent added was changed according to the preparation method of Example 1 (the final volume was the same). The four groups were divided into: A: 20 mL ultrapure water, 7 mL DMF, 3 mL EG; B: 6 mL ultrapure water, 21 mL DMF, 3 mL EG; C: 6 mL ultrapure water, 7 mL DMF, 17 mL EG; D: 20 mL NaOH solution, 7 mL DMF, 3 mL EG. The experimental results are as follows. Figure 7 AC shows TEM images of solvent water, DMF and EG ratios of 20:7:3, 6:21:3, and 6:7:17, respectively. Hydrangea-shaped, rod-shaped and non-mesoporous spherical nanoparticles were synthesized in sequence. The results show that the water solubility of non-mesoporous spherical nanoparticles is poor, the size of rod-shaped nanoparticles is uneven, and the hydrangea-shaped nanoparticles are well dispersed in water, with uniform size and mesopores, which facilitates subsequent use and assembly in the biomedical direction. Therefore, this solvent ratio was selected for subsequent biological application research. The effect of alkaline solvents on the experiment was further explored by replacing the ultrapure water in group A with 0.01M NaOH solution, as shown in Figure 2. Figure 7 As shown in D, hydrangea-shaped nanoparticles can be obtained, but the size is not uniform. Therefore, the best choice is a combination of solvent water, DMF and EG with a ratio of 20:7:3.

[0079] 8. According to the preparation method of Example 1, the present invention explores the effect of the amount of EG on the synthesis of nanoparticles under the same other conditions. Figure 8 As shown in A, when EG is not added, nanoflowers with a size of about 500 nm can be obtained, which are evenly dispersed and uniform in size. Visually, there may be mesopores on the surface. When 3 mL EG is added, the size and morphology of the nanoparticles change dramatically. The particle size becomes significantly smaller and the morphology is similar to that of hydrangea ( Figure 8 B), which makes it possible to apply materials at the biological level. Figure 8 As shown in Figure C, the amount of EG continued to increase to 6 mL, and the size of the nanoparticles further decreased, but the overall structure was loose and there was no complete morphology, which may be detrimental to the stability of the material. The above results show that EG in this system can well regulate the size and morphology of nanoparticles, and with the increase of the amount, the size-dependent decrease is shown, which plays a role in limiting the growth of particles. Therefore, adding 3 mL of EG is the best choice.

[0080] In summary, the controllable synthesis of VS NPs in the present invention requires appropriate reaction temperature, reaction time, type of vanadium source, amount of PVP, type of solvent, solvent ratio and ratio of ligands. Any change in any factor may change the morphology, size and water solubility of the nanoparticles, thereby affecting the performance of the nanoparticles. Therefore, the optimal conditions for synthesizing VS NPs are 0.196g VOSO4, 0.1g 2-aminoterephthalic acid, solvent water, DMF and EG ratio of 20:7:3 (total volume of 30mL), reaction temperature of 160℃, reaction time of 24h. According to the above conditions, VS NPs with uniform morphology and size, good dispersibility and optimal stability can be obtained.

[0081] Example 3

[0082] Furthermore, in order to improve the biocompatibility of VS NPs, the present invention encapsulates BSA on the surface of the nanoparticles to obtain VSB NPs. Fig. 9 As shown in Figure A, after the VS NPs prepared by the method of Example 1 were coated with BSA, the pores of the nanoparticles were almost invisible, and the structure was more compact, but the morphology did not change significantly. A layer of fuzzy material appeared on the edge of the particles, which may be due to the attachment of BSA to the surface of the particles. In addition, the UV-visible-near infrared (UV-vis-NIR) spectra of BSA, VS NPs, and VSB NPs aqueous solution samples were tested. Fig. 9 As shown in Figure B, BSA has a characteristic absorption peak at 278 nm. Compared with VS NPs, VSB NPs also have a peak at 278 nm, proving that VS NPs are successfully encapsulated by BSA. Fig. 9 As shown in C, the surface groups of different samples were characterized by Fourier transform infrared spectroscopy (FT-IR). FTIR spectrum at 989cm -1 The peak at 885 cm is the V═O stretching band, while the peak at 885 cm -1 Corresponding to the VOV vibration mode, it shows that the nanoparticles are mainly vanadium dioxide structures. The FTIR spectrum at 510 cm -1 The peak at 1600-1700 cm-1 was attributed to the -SS- bond, indicating that VS NPs contained disulfide bonds. -1 The peak at belongs to BSA, which means the presence of BSA in VSB NPs. The above experimental results indicate the successful synthesis of VSB NPs.

[0083] The VSB NPs prepared in Example 1 were dispersed in water. The present invention used a near-infrared laser (1064 nm, 1.0 W cm -2 ) irradiated VSB NPs aqueous solution (60 μg mL -1 )10min. Fig.10 As shown in A, the photothermal conversion efficiency was 50%, which is relatively high compared with most of the previously reported PTT agents, such as V2C (48%), VS2 (31.5%), and V NSs (16.09%). Fig.10 As shown in Figure B, the VSB NPs aqueous solution was continuously irradiated with NIR-II laser four times, and the real-time temperature was recorded. The temperature change trend of each cycle was consistent, indicating that VSB NPs have high photothermal stability. The above experimental results show that VSB NPs have stable and excellent photothermal performance. It proves that VSB NPs have the advantage of photothermal ablation of tumor cells.

[0084] In Example 1 of the present invention, VS NPs were prepared using 3,3-dithiodipropionic acid as a ligand, and a disulfide bond that can consume GSH was introduced, such as Fig.11 As shown in A, 508cm -1 The peak at is the Raman spectrum of disulfide bonds in aqueous media. -1 ) after adding GSH (1M), 508cm -1 The Raman peak at 10 mg mL -1 ), VS NPs (10 mg mL -1 )+GSH(1M) and VS NPs(10mg mL -1 )+H2O2(1M) solution after drying. Fig.11 As shown in B, from the V 2p XPS spectrum, the BE of the two energy bands of VS is 515.54 eV (V2p 3 / 2 ) and 522.72eV(V 2p 1 / 2 ) corresponds to V 4+ ; When VS reacts with GSH, the valence state of the vanadium ion does not change because V 3+ The binding energy is lower than V 4+ In fact, after the reaction with GSH, the BE of the two energy bands of VSB NPs increased slightly, indicating that the presence of GSH filled the oxygen vacancies in VS itself. Therefore, this is most likely due to the destruction of the disulfide bonds in VS without causing V 4+ To V 3+ After adding H2O2 to VS, the solution changed from black to brown in just 1 hour, indicating that a violent redox reaction occurred. The XPS spectrum showed that the BE of the two energy bands of VS was 517.46 eV (V 2p 3 / 2 ) and 524.6eV(V 2p 1 / 2 ) corresponds to V 5+ , V 4 +The peak of V with variable valence can be oxidized by H2O2 to produce a Fenton-like reaction (V 4+ +H2O2+H + →V 5+ +·OH+H2O). At the same time, vanadium exists in a pentavalent form, and the degradation product may be water-soluble V oxides, such as VO2 + , VO4 3- and VO3 - . This lays the foundation for the study of the biological effects of vanadium itself in anti-tumor mechanisms. In a physiological environment, the pH value of the extracellular matrix of normal tissues is about 7.4, while the tumor microenvironment is weakly acidic. A lower pH value is conducive to the degradation of nanoparticles. If VSBNPs degrade under acidic conditions, it is also beneficial for the treatment of cancer without harming normal cells. Therefore, the release of V under different conditions was evaluated by ICP-OES. Fig.11 As shown in C, VSB NPs (1 mg mL -1 ) After incubation in PBS at pH 5.5 for 12 h, the V release rate was 28%; in comparison, at pH 7.4, the V release rate was only 12%, indicating that VSB NPs have a good ability to release V under acidic conditions, and after incubation in an acidic buffer containing GSH (10 mM) at pH 5.5 for 12 h, the V release rate was as high as 72%. The above results show that the release of vanadium ions reaches the maximum under the dual response conditions of acidity and GSH.

[0085] 5,5-Dithiobis(2-nitrobenzoic acid) (DTNB) was used as a thiol colorimetric agent to evaluate the consumption capacity of VSB NPs for GSH. Colorless DTNB can react with thiol compounds to convert into yellow 5-mercapto-2-nitrobenzoic acid (TNB), which has a characteristic absorption peak at 412 nm. Specifically, 6.25 mg of GSH and DTNB were weighed and dissolved in 2.5 mL (pH = 8.5) buffer solution, GSH (70 μL) and DTNB (50 μL) were fixed to 2 mL with buffer solutions of different pH values, incubated together for 10 min, and VSB NPs (40 μg mL -1 ) for different reaction times. The supernatant was collected by centrifugation and the absorbance at 412 nm was detected by UV-vis absorption spectroscopy. The absorbance at 412 nm gradually decreased with the extension of incubation time ( Fig.11 D), verifying that VSB NPs have glutathione peroxidase (GPx)-like activity. The above experimental results show that VSB NPs contain disulfide bonds and can effectively consume GSH, and can be effectively degraded in the presence of GSH and in a slightly acidic environment. This proves that VSB NPs have the advantages of biodegradability and consumption of GSH.

[0086] The present invention evaluates the peroxidase (POD)-like activity of VSB NPs. Nanozymes with POD-like activity can catalyze the conversion of H2O2 to generate ·OH. 3,3',5,5'-tetramethylbenzidine (TMB) was used to determine the generation of ·OH. The generated ·OH can oxidize the colorless TMB into its oxidized form oxTMB, which exhibits a distinct blue color and a characteristic absorption peak at 652nm. 20μL of TMB (10mg mL -1 ) was added to VSB NPs (40 μg mL -1 , 2 mL) solution, and then different treatments: with or without H2O2 (20 mM), different pH solutions (pH 5.5, 7.4), no illumination and illumination (1064 nm, 1.0 W cm -2 , 10min). Then the absorbance of the mixed solution at 652nm was measured by UV-vis spectrophotometry. Fig.12 As shown in A, no oxidation reaction occurred when TMB and H2O2 were used alone. No oxidation reaction occurred when VSBNPs were added to TMB and H2O2. However, as expected, in an environment containing TMB and H2O2, a characteristic peak at 652 nm was clearly observed in the UV-vis spectrum when VSB NPs were added, confirming the generation of ·OH. Singlet oxygen ( 1 O2) production, DPBF can capture 1 O2, resulting in a decrease in the absorbance of DPBF at 425 nm. Typically, DPBF solution (10 μL, 20 mg mL -1 ) was added to VSB NPs (40 μg mL -1 , 2mL) solution. The absorbance of DPBF at 425nm at different time points under different conditions was detected. Fig.12 As shown in B, when H2O2 and VSB NPs exist alone, the absorption peak of DPBF does not decrease significantly. However, when VSB NPs are mixed with H2O2, its characteristic absorption peak shows an obvious time-dependent downward trend, confirming that VSB NPs have the ability to produce 1 O2 capabilities; in particular, the 1 The generation of O2 does not require additional light source excitation, which is different from the photosensitizer 1 O2 requires sufficient oxygen and additional light sources. After VSB NPs were mixed with H2O2 and irradiated with 1064nm laser, the characteristic absorption peak of DPBF decreased more significantly, indicating that photothermal enhancement 1 The above in vitro simulation experimental results show that VSB NPs can produce ·OH and1 O2 (all belong to ROS). It proves that VSB NPs have the advantage of producing ROS in the acidic microenvironment of tumors.

[0087] The present invention quantitatively evaluates the cytotoxicity of VSB NPs to L02 normal hepatocytes and macrophages and MCF-7 cells to assess their effects on cell viability. The specific experiment is as follows: L02 cells, RAW 264.7 cells and MCF-7 cells were inoculated on 96-well plates and incubated for 24 hours. When the cell density measured by the cell counter was 8000 cells / well, the plates were replaced with plates containing different concentrations of VSB NPs (0, 20, 40, 60, 80 and 100 μg mL -1 ) medium for 24 h, then discard the old medium, add 200 μL of fresh DMEM to each well, and add 20 μL of 5 mg mL -1 MTT solution. After 4 hours of incubation, discard the culture medium. Add 150 μL of dimethyl sulfoxide (DMSO) to the above single well, shake on the microplate reader for 10 minutes to fully dissolve the purple formazan, and then measure the absorbance at 570 nm. Fig.13 As shown in A, Raw264.7 macrophages were incubated with VSB NPs for 24 h. -1 At high concentrations, the survival rate is still higher than 80%; Fig.13 As shown in B, no obvious cytotoxicity was observed after L02 normal hepatocytes were incubated with VSBNPs for the same time. In contrast, only 55% of the tumor cells survived after MCF-7 cells were treated with VSB NPs. Fig.13 C combined with 1064nm laser (1.0W cm -2 After irradiation for 10 minutes, the survival rate dropped to 36%, indicating that VSB NPs have significant tumor cell inhibition properties. The above experimental results show that VSB NPs have no toxic side effects on normal cells, but have a good killing effect on tumor cells. It proves that VSB NPs have the advantage of selectively killing tumor cells.

[0088] The present invention uses 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) to evaluate the level of ROS in cells in vitro. The specific experiment is as follows: MCF-7 cells were inoculated in a laser confocal dish and cultured for 24 hours. The number of cells in each well reached 2×10 5 And compared with different groups: Ⅰ.Control; Ⅱ.L; Ⅲ.VSB NPs (100μg mL -1 ); IV.VSB NPs (100 μg mL -1 )+L, after incubation for 4 h, the illumination group was irradiated with 1064 nm laser 1.0 W cm-2 After irradiation for 10 min, each group was incubated for 8 h. The culture medium was washed 3 times with PBS, and then the DCFH-DA probe was added and incubated with the cells for 30 min, washed 3 times with PBS, stained with Hoechst33342 for 20 min, washed 3 times with PBS, and the fluorescence images were recorded with CLMS. Fig.14 A shows that the MCF-7 cells in the control group and the L group had almost no fluorescence, indicating that the intracellular ROS level was extremely low, eliminating the effect of L alone on ROS; on the contrary, obvious green fluorescence was observed in the VSB NPs-treated group, among which the fluorescence intensity of the VSB NPs+L group was the strongest, indicating that light enhanced the generation of ROS. As one of the key biomarkers of ferroptosis, the detection of LPO uses C11-BODIPY as a ratiometric fluorescence indicator. After C11-BODIPY is oxidized, its fluorescence changes from red to green, which facilitates the detection of LPO. MCF-7 cells were seeded in a laser confocal dish and cultured for 24 hours, and the number of cells in each well reached 2×10 5 and were divided into different groups: Ⅰ.Control; Ⅱ.L; Ⅲ.VSB NPs (100 μg mL -1 ); IV.VSB NPs (100 μg mL -1 )+L, after incubation for 4 h, the illumination group was irradiated with 1064 nm laser 1.0 W cm -2 Irradiation was performed for 10 min, and each group was incubated for 20 h. Then, the cells were stained with BODIPY 581 / 591C11 and incubated for 20 min. After washing with PBS three times, the nuclei were stained with Hoechst 33342, and fluorescence imaging was performed using CLSM. As expected, cells treated with VSB NPs+L group showed the dimmest red fluorescence and the brightest green fluorescence ( Fig.14 B), indicating the highest level of lipid peroxidation. The above experimental results show that VSB NPs can effectively induce ferroptosis of tumor cells, and photothermal enhancement of this form of death. It proves that VSB NPs can achieve the advantage of consuming GSH and generating ROS in tumor cells at the same time, leading to ferroptosis of tumor cells.

[0089] The present invention predicts that vanadate after degradation of VSB NPs may inhibit Na + / K + ATPase activity and induce K + MCF-7 cells were incubated with sodium sulfate (Na2SO4), sodium orthovanadate (Na3VO4), sodium metavanadate (NaVO3), VSB NPs, and VSB NPs+L to detect their effects on Na + / K +ATPase activity. MCF-7 cells were cultured at 5×10 6 Cells were seeded at a density of 10 cells / well in 6-well plates. -1 )、VSB NPs(100μg mL -1 + L were co-cultured for 24 h, where VSB NPs (100 μg mL -1 The +L group needed to be exposed to 1064 nm NIR laser (1.0 W cm -2 ) After the culture was completed, the supernatant was discarded, the cells were digested with trypsin, and the cells were collected and centrifuged (3000 rpm). The supernatant was discarded and physiological saline was added for later use. The cells were ultrasonically treated on ice (power 25%, ultrasonic treatment for 3s, pause for 10s, repeated 30 times). + / K + ATPase maintains a high potassium-sodium ratio by hydrolyzing ATP and decomposing ATP to produce ADP and inorganic phosphorus. Measuring inorganic phosphorus content can determine ATPase activity. In this case, Na + / K + ATPase activity. Fig.15 As shown in A, as expected, both vanadate and VSB NPs were able to inhibit the + / K + ATPase activity, among which, VSB NPs+L group had a significant effect on membrane Na + / K + ATPase activity showed the strongest inhibition, while Na2SO4 had a negligible inhibitory effect on enzyme activity, indicating that vanadium species may have biospecific effects. + MCF-7 cells were seeded into confocal dishes, with the number of cells in each well reaching 2×10 5 The culture medium was replaced with 2 mL of DMEM and VSB NPs (100 μg mL -1 ) and incubated for 12 h. In the illumination group, a 1064 nm NIR laser (1.0 W cm -2 ) for 10 min; the cells were washed three times with PBS, and then enhanced potassium green-2AM (EPG-2AM 2 μM, Maokang Biotechnology), a K +The probe was added and incubated at 37°C for 60 min. Finally, the medium was replaced and washed with fresh serum-free medium. The staining process was consistent with the manufacturer's protocol, and fluorescence was observed under CLSM. The experimental results showed that after cancer cells were treated with VSB NPs or VSB NPs+L, the K + The level dropped significantly ( Fig.15 B) This is related to Na + / K + The results of ATPase inhibition are consistent with those of ATPase inhibition. + Outflow can cause the activation of NLRP3 inflammasomes and the maturation of pro-IL-1β, and the activation of inflammasomes helps to induce pyroptosis of tumor cells. At the same time, it shows that the material prepared by the present invention can inhibit the Na + / K + ATPase activity, thereby causing K + This laid the foundation for the pyroptosis of tumor cells, proving that the material is a potential agent for inducing tumor pyroptosis. The expression of NLRP3 in cancer cells was further studied. The NLRP3 inflammasome in MCF-7 breast tumor cells was measured. The cells were seeded in a laser confocal dish and cultured for 24 hours. The number of cells in each well reached 2×10 5 The medium was replaced with fresh DMEM containing different materials: Ⅰ. Control; Ⅱ. L; Ⅲ. VSB NPs (100 μg mL -1 ); IV.VSB NPs (100 μg mL -1 )+L, after incubation for 4 h, the illumination group was irradiated with 1064 nm 1.0 W cm -2 Irradiate for 10 minutes. Each group was then incubated for 20 hours. Next, the cells were fixed with paraformaldehyde (4%) for 15 minutes, permeabilized with Triton-X100 (1%), blocked with BSA (3%) for 1 hour and then discarded, and then incubated with an appropriate amount of primary antibody NLRP3 overnight. The adherent cells were rinsed 3 times with PBS and incubated with secondary antibodies at room temperature for 2 hours, and finally counterstained with Hoechst 33342, and immunofluorescence was detected by CLSM. Fig.15 As shown in Figure C, weak green fluorescence can be seen in the control group and the light-irradiated group, while the green fluorescence in MCF-7 cells was significantly enhanced after treatment with VSB NPs, indicating that VSB NPs can induce the expression of NLRP3 in tumor cells, and after near-infrared light irradiation, the green fluorescence is further enhanced, indicating that photothermal enhancement of NLRP3 expression. The above experimental results show that VSB NPs can effectively induce tumor cell pyroptosis, and light can enhance this form of death, proving that VSB NPs have the advantage of being degraded into high-valent vanadates to kill cancer cells with their own biological effects.

[0090] In order to visually distinguish live cells from dead cells, the present invention uses calcein (AM) and propidium iodide (PI) to stain the treated cells. MCF-7 cells were inoculated in a laser confocal dish and cultured for 24 hours. The number of cells in each well reached 2×10 5 The medium was replaced with fresh DMEM containing different materials: Ⅰ. Control; Ⅱ. L; Ⅲ. VSB NPs (100 μg mL -1 ); IV.VSB NPs (100 μg mL -1 )+L, after incubation for 4 h, the illumination group was 1064 nm at 1.0 W cm -2 Irradiation was performed for 10 min. Each group was then incubated for 20 h. The culture medium was washed three times with PBS, and then calcein AM and propidium iodide PI reagents were added to stain live cells with green fluorescence and dead cells with red fluorescence. Finally, fluorescence imaging was performed using CLSM. Fig.16 As shown in the figure, compared with the control group, the amount of cell death in the illumination group was negligible, while after incubation with VSB NPs, a huge change in cell morphology was observed, from spindle-shaped to round, indicating that VSB NPs have obvious therapeutic effects; further, after VSB NPs were illuminated, the red light increased significantly and the green light was almost invisible. The experimental results show that almost all cancer cells were killed, proving that VSB NPs have the ability to effectively kill cancer cells, and the therapeutic effect is better after illumination.

Claims

1. A method for preparing vanadium dioxide nanoparticles containing disulfide bonds, characterized in that: The steps include: (1) Dissolve polyvinyl pyrrolidone (PVP) in ultrapure water and stir vigorously; (2) Mix VOSO4 with ultrapure water and disperse by ultrasonication; (3) Transferring the VOSO4 aqueous solution to the PVP solution for reaction; (4) dissolving 3,3-dithiodipropionic acid and 2-aminoterephthalic acid in organic solvents respectively, and then adding them into the mixed solution of step (3) to react; (5) adding ethylene glycol and triethylamine to the solution after the reaction in step (4); stirring and then performing a hydrothermal reaction, collecting the solution, and washing by centrifugation to obtain VS NPs; (6) Dissolve VS NPs in buffer, add BSA and stir to obtain VSB NPs.

2. The preparation method according to claim 1, characterized in that: The feed mass ratio of PVP in step (1) to VOSO4 in step (2) is 1-20:1-4.

3. The preparation method according to claim 1, characterized in that: In step (3), the VOSO4 aqueous solution is transferred to the PVP solution and stirred at room temperature for 1 to 2 hours.

4. The preparation method according to claim 1, characterized in that: In step (4), the feed ratio of 3,3-dithiodipropionic acid to 2-aminoterephthalic acid is 1-5:2-10.

5. The preparation method according to claim 1, characterized in that: The temperature of the hydrothermal reaction in step (5) is 120° C. to 180° C., and the time is 6 h to 48 h.

6. The preparation method according to claim 1, characterized in that: In step (6), VS NPs are dissolved in PBS, a Tris-HCl solution of BSA is added, and the mixture is stirred at 50-60° C. for 1-2 h to obtain VSB NPs.

7. Vanadium dioxide nanoparticles containing disulfide bonds prepared by the preparation method according to claim 1.

8. The vanadium dioxide nanoparticles containing disulfide bonds according to claim 1, characterized in that: The nanoparticles preferably have a hydrangea structure and a size of about 130 nm.

9. Use of the vanadium dioxide nanoparticles containing disulfide bonds according to claim 7 in the preparation of anti-tumor agents or drugs.

10. The use according to claim 9, characterized in that: The vanadium dioxide nanoparticles containing disulfide bonds can effectively inhibit tumor growth by photothermally enhancing multi-mode combined treatment of tumor cell ferroptosis and pyroptosis, and are used in the preparation of anti-tumor reagents or drugs.

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