Graphene quantum dot nanosheet as well as preparation method and application thereof

Abstract

The invention discloses a preparation method and application of a graphene quantum dot nanosheet. The method comprises the following steps: S1, carrying out hydrothermal reaction on a mixed solution containing magnesium oxide nanosheets and a carbon source to obtain graphene-coated magnesium oxide nanosheets; and S2, mixing the graphene-coated magnesium oxide nanosheet with an inorganic acid solution, removing the magnesium oxide nanosheet, and carrying out rotary evaporation, freeze drying and washing to obtain the graphene quantum dot nanosheet, wherein the carbon source is selected from at least one of ammonium citrate, diammonium hydrogen citrate, citric acid, folic acid, urea, thiourea and dicyanodiamine; the inorganic acid is selected from at least one of hydrochloric acid and sulfuric acid. The graphene quantum dot nanosheet is prepared by adopting a hard template method taking the magnesium oxide nanosheet as a template agent, and controllable preparation of the graphene quantum dot nanosheet can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of biomedical materials, and in particular to a graphene quantum dot nanosheet and a preparation method and application thereof. Background Art

[0002] In recent years, the chemotherapeutic effects of platinum nanoparticles (PtNPs) have garnered widespread attention. In the specialized tumor microenvironment (e.g., high acidity and elevated hydrogen peroxide concentrations), highly active PtNPs, due to their surface effects, undergo oxidative decomposition, releasing cytotoxic platinum ions or related divalent platinum complexes, resulting in a chemotherapeutic effect. Furthermore, in normal neutral or weakly alkaline body fluids, PtNPs are resistant to oxidative decomposition and accumulate in tumor tissues through the enhanced permeability and retention (EPR) effect, resulting in reduced toxicity compared to platinum-based drugs. Furthermore, PtNPs are multifunctional antitumor agents, possessing unique properties such as artificial enzymes, high-energy radiation sensitization, and efficient photothermal conversion. Therefore, compared to commonly used platinum-based drugs such as cisplatin and oxaliplatin, chemotherapeutic PtNPs exhibit lower toxicity and side effects, and also demonstrate significant inhibitory effects against some tumors resistant to platinum-based drugs. PtNP-based chemotherapy drugs are expected to become the next generation of platinum-based anticancer drugs.

[0003] The clinical application of PtNPs chemotherapy drugs still faces huge challenges. The main reasons are: 1) Direct wet reduction in the presence of stabilizers and reducing agents (such as sodium borohydride, hydrazine hydrate, ascorbic acid, etc.) to obtain ultrafine PtNPs is a widely used synthesis method. During the synthesis process, stabilizers, reducing agents, high-valent platinum compounds, organic solvents, reaction by-products, and toxin or bacterial contamination may all be sources of toxic side effects in the body, resulting in a relatively complicated purification process for nanomedicines; 2) Intravenously injected nanomedicines must undergo a five-step cascade process of blood circulation, tumor accumulation, intratumor penetration, endocytosis by cancer cells, and intracellular release before they can exert their efficacy in tumor cells. The lack of penetration ability in tumor tissue is the "shortcoming" of most nanomedicines. Their delivery efficiency in tumors is less than 0.7%, mainly due to poor dispersibility and solubility; 3) The physicochemical stability, pharmacology, pharmacokinetics, and toxicology of the drug need to be comprehensively evaluated to verify the efficacy and safety of the drug.

[0004] Graphene quantum dots (GQDs) are a new type of zero-dimensional carbon-based nanomaterial composed of tiny graphene fragments (2-100 nm). They offer unique advantages in the field of tumor diagnosis and treatment, including unique fluorescence generated by quantum confinement, abundant active sites, tunable physicochemical properties, photoreactive oxygen generation, efficient photothermal effects, good solubility, high biocompatibility, and strong binding to proteins and DNA. Therefore, as a multifunctional nanoplatform, GQDs show great application prospects in tumor diagnosis, cell imaging, drug loading and release, photodynamic therapy, and near-infrared photothermal therapy. Using highly biocompatible GQDs to protect chemotherapeutic PtNPs effectively improves drug dispersibility and solubility. Furthermore, through the EPR effect, the accumulation of chemotherapeutic drugs in PtNPs@GQDs within tumor tissue is enhanced, enabling passive targeting of the drug to cancer cells.

[0005] However, the controllability of the particle size of graphene quantum dot nanosheets affects their composite effect with PtNPs, which further affects the medical effect of PtNPs in anti-tumor drugs; therefore, it is very important to controllably prepare graphene quantum dot nanosheets with a specific particle size. Summary of the Invention

[0006] In view of this, the present application provides a graphene quantum dot nanosheet and its preparation method and application, the main purpose of which is to solve the problem of controlling the particle size of graphene quantum dot nanosheet.

[0007] In one aspect, the present application provides a method for preparing graphene quantum dot nanosheets, the method comprising the following steps:

[0008] S1: A mixed solution containing magnesium oxide nanosheets and a carbon source is subjected to a hydrothermal reaction to obtain graphene-coated magnesium oxide nanosheets;

[0009] S2: mixing the graphene-coated magnesium oxide nanosheets and an inorganic acid solution, removing the magnesium oxide nanosheets, and then subjecting the mixture to rotary evaporation, freeze drying, and washing to obtain the graphene quantum dot nanosheets;

[0010] Wherein, the carbon source is selected from at least one of ammonium citrate, diammonium hydrogen citrate, citric acid, folic acid, urea, thiourea, and dicyandiamide;

[0011] The inorganic acid is selected from at least one of hydrochloric acid and sulfuric acid.

[0012] The present invention adopts a hard template method using magnesium oxide nanosheets as a template agent to prepare graphene quantum dot nanosheets, which can achieve controllable preparation of the graphene quantum dot nanosheets.

[0013] Optionally, the ammonium citrate comprises triammonium citrate.

[0014] Optionally, in step S1, the mass ratio of the magnesium oxide nanosheets to the carbon source is 1:0.8-1.6.

[0015] Optionally, the mass ratio of the magnesium oxide nanosheets to the carbon source is selected from 1:0.8, 1:0.9, 1:1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, and 1:1.6.

[0016] Optionally, the particle size of the magnesium oxide nanosheets is selected from any value among 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, or any range between two values.

[0017] Optionally, the reaction temperature of the hydrothermal reaction in step S1 is 200° C. to 220° C., and the reaction time is 8 to 12 hours.

[0018] Optionally, the reaction temperature is selected from any value among 200, 205, 210, 215, 220 or any range between two values, in °C.

[0019] Optionally, the reaction time is selected from any value among 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, or any range between two values, in hours (h).

[0020] Optionally, the specific process of step S1 includes: adding the carbon source and deionized water to the system in which the magnesium oxide nanosheets are dispersed to form the mixed solution, and performing the hydrothermal reaction after ultrasonically dissolving the mixed solution.

[0021] Optionally, the ultrasonic dissolution time is 5 to 20 minutes.

[0022] Optionally, the ultrasonic dissolution time is selected from any value among 5, 8, 10, 12, 15, 20 or any range between two values, in minutes (min).

[0023] The ultrasonic dissolution time in the present invention can be adjusted according to the actual dissolution situation.

[0024] Optionally, the reaction liquid after the hydrothermal reaction in step S1 is cooled and centrifuged to remove particle residues to obtain the graphene-coated magnesium oxide nanosheets.

[0025] Optionally, the cooling is natural cooling to room temperature, the centrifugal speed is 12000 r / min, the centrifugal time is 5 min, and the particle residue is large orange-yellow particles.

[0026] The centrifugal speed and time described in the present invention can be adjusted according to the actual separation effect.

[0027] Optionally, in step S2, the graphene-coated magnesium oxide nanosheets are immersed in the inorganic acid solution at room temperature to remove the magnesium oxide nanosheets.

[0028] The number of times of washing with anhydrous ethanol in the present invention can be adjusted according to the actual washing effect of the product.

[0029] In a second aspect, the present invention provides a graphene quantum dot nanosheet, which is prepared using the above-mentioned preparation method.

[0030] Optionally, the particle size of the graphene quantum dot nanosheets is 15 nm to 40 nm, further 15 nm to 30 nm.

[0031] Optionally, the particle size of the graphene quantum dot nanosheets is selected from any value among 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or any range between two values, in nm.

[0032] The graphene quantum dots of the present invention are light yellow graphene quantum dots that are insoluble in ethanol.

[0033] In a third aspect, the present invention provides the use of the above-mentioned graphene quantum dot nanosheets in the preparation of tumor diagnosis and / or cell imaging tracers, and in the preparation of photodynamic therapy or near-infrared photothermal therapy drugs.

[0034] Optionally, the graphene quantum dot nanosheets are used in the preparation of anti-tumor drug carriers.

[0035] Optionally, the graphene quantum dot nanosheets serve as carriers and are loaded with targeting molecules.

[0036] Optionally, the targeting molecule is selected from at least one of biotin, folic acid, RGD peptide, hyaluronic acid, and TAT transmembrane peptide.

[0037] In a fourth aspect, the present invention provides a platinum nanoparticle / graphene quantum dot composite nanomaterial, wherein the platinum nanoparticles are dispersed in an amorphous graphene quantum dot matrix in the form of aggregates; wherein the graphene quantum dots are selected from the above-mentioned graphene quantum dot nanosheets.

[0038] The composite nanomaterial of this invention utilizes highly biocompatible graphene quantum dots to protect platinum nanoparticles with chemotherapeutic properties. This effectively improves the dispersibility and solubility of the drug. This enhanced permeability and retention enhances the accumulation of the platinum nanoparticle / graphene quantum dot composite drug in tumor tissue, passively targeting cancer cells. Furthermore, the graphene quantum dots, acting as nanocarriers, can be loaded with bioactive agents and targeting agents (such as antibodies, folic acid, RGD peptide, hyaluronic acid, and TAT transmembrane peptides), enhancing the active targeting capability of the composite drug, enhancing tumor therapeutic efficacy, and reducing toxic side effects.

[0039] In a fifth aspect, the present invention provides a method for preparing the above-mentioned platinum nanoparticle / graphene quantum dot composite nanomaterial, comprising: obtaining graphene quantum dots; subjecting a mixture of the graphene quantum dots, a platinum source, and a reducing agent to thermal reduction to obtain the composite nanomaterial; the graphene quantum dots are prepared by any of the above-mentioned preparation methods.

[0040] Optionally, the reducing agent is selected from methanol and / or ethanol.

[0041] Optionally, the platinum source is selected from at least one of sodium chloroplatinite, potassium chloroplatinite, ammonium chloroplatinite, platinum tetrachloride, chloroplatinic acid, and sodium chloroplatinate.

[0042] Optionally, the ratio of the graphene quantum dots to the platinum source is 1g:(0.2-0.4)g.

[0043] Optionally, the thermal reduction process includes:

[0044] The first stage: 45-55℃ reaction for 0.3-0.8h;

[0045] The second stage: react at 55-65℃ for 0.8-1.2h.

[0046] Optionally, the thermal reduction process includes:

[0047] The first stage: 50℃ reaction for 0.5h;

[0048] Second stage: react at 60℃ for 1h.

[0049] This invention uses a simple thermal reduction synthesis method to synthesize highly soluble platinum nanoparticle / graphene quantum dot chemotherapy drugs at the gram level. During the preparation process, no toxic reducing agents are required. The graphene quantum dots serve as a multifunctional auxiliary matrix and stabilizer for the ultrafine platinum nanoparticles with chemotherapeutic effects.

[0050] In a sixth aspect, the present invention provides the use of the above-mentioned platinum nanoparticle / graphene quantum dot composite nanomaterial in the preparation of anti-tumor drugs.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] 1) The present invention adopts a hard template method using magnesium oxide nanosheets as a template to prepare graphene quantum dots, which can achieve controllable preparation of graphene quantum dot nanosheets; that is, by adjusting the particle size range of magnesium oxide nanosheets, controllable modulation of graphene quantum dots can be achieved.

[0053] 2) The present invention uses magnesium oxide nanosheets as hard templates to produce graphene quantum dot nanosheet particles with a particle size of 10nm to 40nm.

[0054] 3) The raw materials for preparing graphene quantum dot nanosheets provided by the present invention are all industrial raw materials and can be produced on a large scale industrially.

[0055] 3) The graphene quantum dot nanosheets provided by the present invention have a wider range of applications when used as drug carriers.

[0056] 4) The platinum nanoparticle / graphene quantum dot composite nanomaterial provided by the present invention has high solubility, stable physicochemical properties, and significant chemotherapy effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 is the X-ray powder diffraction pattern of GQDs provided in Example 1 of the present invention;

[0058] Figure 2 is a transmission electron microscopy image of GQDs provided in Example 1 of the present invention;

[0059] Figure 3 This is a transmission electron microscope image of PtNPs@GQDs provided in Example 5 of the present invention. DETAILED DESCRIPTION

[0060] The present application will be further described below in conjunction with specific embodiments. The following description is merely a few embodiments of the present application and does not limit the present application in any form. Although the present application discloses the preferred embodiments below, it is not intended to limit the present application. Any person skilled in the art who, without departing from the scope of the technical solution of the present application, makes slight changes or modifications using the above disclosed technical content is equivalent to an equivalent implementation case and falls within the scope of the technical solution.

[0061] Unless otherwise specified, the raw materials in the examples of this application were purchased from commercial channels and used directly without any special treatment.

[0062] In the embodiment, X-ray powder diffraction phase analysis (XRD) was carried out on a Rigaku Miniflex II X-ray diffractometer at 30 kV, 15 mA, Cu target, Kα radiation source.

[0063] In the examples, transmission electron microscopy and high-resolution transmission electron microscopy analysis were performed using a Tecnai F20 field emission transmission electron microscope.

[0064] In the examples, the magnesium oxide nanosheets used were commercially available and prepared by the following method: 10 g of MgCl2 and 6 g of CO(NH2)2 were dissolved in 200 mL of deionized water, stirred for half an hour, and then transferred to a polytetrafluoroethylene-lined reactor for rotational crystallization at 190°C for 12 hours. The resulting MgO nanosheets were then washed with deionized water and dried at 120°C.

[0065] Example 1

[0066] To a system in which 5 g of magnesium oxide nanosheets were dispersed, 4.5 g of triammonium citrate was added to the polytetrafluoroethylene lining of the reactor (volume of 100 ml), 60 ml of deionized water was added, ultrasonically dissolved for 10 minutes, and then hydrothermally reacted at 210°C for 10 hours. After the resulting reaction solution was naturally cooled to room temperature, it was centrifuged at high speed (12000 r / min) for 5 minutes to remove the orange-yellow large particle residue in the solution to obtain graphene-coated magnesium oxide nanosheets; the graphene-coated magnesium oxide nanosheets were immersed in hydrochloric acid solution, after removing the magnesium oxide nanosheets, the centrifuge liquid was vacuum rotary evaporated at 60°C to near dryness to remove volatile small molecules in the solution, and then rotary evaporated to obtain an orange-yellow viscous substance, which was then freeze-dried to remove the solvent water, and finally washed and centrifuged with anhydrous ethanol several times to obtain light yellow graphene quantum dots insoluble in ethanol, recorded as sample GQDs1#.

[0067] The characteristics of graphene quantum dots can be known through testing: the powder diffraction results of sample GQDs1# are as follows Figure 1 As shown in the transmission electron microscope test, the sample GQDs1# is composed of 10 to 40 nm graphene quantum dots stacked together to form nanosheets (such as Figure 2 shown).

[0068] Example 2

[0069] To a system in which 5 g of magnesium oxide nanosheets were dispersed, 4.5 g of citric acid and 3 g of urea were added to the polytetrafluoroethylene lining of the reactor (volume 100 ml), 60 ml of deionized water was added, ultrasonically dissolved for 10 minutes, and then hydrothermally reacted at 215°C for 9.5 hours. The resulting reaction solution was naturally cooled to room temperature and centrifuged at high speed (12000 r / min) for 5 minutes to remove the large orange-yellow particles in the solution to obtain graphene-coated magnesium oxide nanosheets; the graphene-coated magnesium oxide nanosheets were immersed in sulfuric acid solution, and after removing the magnesium oxide nanosheets, the solvent water was removed by rotary evaporation and freeze-drying, and then washed and centrifuged with anhydrous ethanol several times to obtain light yellow graphene quantum dots insoluble in ethanol, which were recorded as sample GQDs2#.

[0070] The powder diffraction results of the obtained sample are similar to those of sample GQDs1#, with the same diffraction peak positions and a slight variation in peak intensity within the range of ±10%. The transmission electron microscopy images of the obtained sample are similar to those of sample GQDs1#.

[0071] Example 3

[0072] To a system in which 5 g of magnesium oxide nanosheets were dispersed, 4.5 g of citric acid and 3 g of dicyandiamide were added to the polytetrafluoroethylene lining of the reactor (volume 100 ml), 60 ml of deionized water was added, ultrasonically dissolved for 10 minutes, and then hydrothermally reacted at 220°C for 8.5 hours. The resulting reaction solution was naturally cooled to room temperature and centrifuged at high speed (12000 r / min) for 5 minutes to remove the large orange-yellow particles in the solution to obtain graphene-coated magnesium oxide nanosheets; the graphene-coated magnesium oxide nanosheets were immersed in sulfuric acid solution, and after removing the magnesium oxide nanosheets, the solvent water was removed by rotary evaporation and freeze-drying, and then washed and centrifuged with anhydrous ethanol several times to obtain light yellow graphene quantum dots insoluble in ethanol, which were recorded as sample GQDs3#.

[0073] The powder diffraction results of the obtained sample are similar to those of sample GQDs1#, with the same diffraction peak positions and a slight variation in peak intensity within the range of ±10%. The transmission electron microscopy images of the obtained sample are similar to those of sample GQDs1#.

[0074] Example 4

[0075] To a system in which 5 g of magnesium oxide nanosheets were dispersed, 4.5 g of citric acid and 2 g of thiourea were added to the polytetrafluoroethylene lining of the reactor (volume 100 ml), 60 ml of deionized water was added, ultrasonically dissolved for 10 minutes, and then hydrothermally reacted at 212°C for 10 hours. The resulting reaction solution was naturally cooled to room temperature and centrifuged at high speed (12000 r / min) for 5 minutes to remove the large orange-yellow particles in the solution to obtain graphene-coated magnesium oxide nanosheets; the graphene-coated magnesium oxide nanosheets were immersed in sulfuric acid solution, and after removing the magnesium oxide nanosheets, the solvent water was removed by rotary evaporation and freeze-drying, and then washed and centrifuged with anhydrous ethanol several times to obtain light yellow graphene quantum dots insoluble in ethanol, which were recorded as sample GQDs4#.

[0076] The powder diffraction results of the obtained sample are similar to those of sample GQDs1#, with the same diffraction peak positions and a slight variation in peak intensity within the range of ±10%. The transmission electron microscopy images of the obtained sample are similar to those of sample GQDs1#.

[0077] Example 5 Preparation of PtNPs@GQDs chemotherapy drugs

[0078] Weigh 1.2 grams of the above sample GQDs1# precursor into a round-bottom flask and add 20 ml of deionized water to dissolve it. Prepare 600 mg of Na2PtCl4 (platinum content>48%) in 20 ml of deionized water, slowly add it dropwise to the GQDs aqueous solution, stir to react, and then add 20 ml of anhydrous ethanol. Slowly heat the reaction solution to 50°C and react at this temperature for 0.5 hours. The color of the solution changes from yellow to brown, indicating that platinum nanoparticles are slowly formed. Slowly heat the reaction solution to 60°C again and react at this temperature for 1 hour. The color of the solution gradually darkens and finally presents a brown-black clear liquid. After stopping the reaction, vacuum evaporation (50°C) is used to remove ethanol to a volume of about 20 ml of the aqueous solution, and the pH value of the solution is adjusted to 7-7.5 with NaOH. Centrifuge the solution at high speed (12000r / min) for 4 minutes to remove a very small amount of large black particles in the solution. The brown-black clear liquid was freeze-dried to obtain a black solid, which was washed with ethanol and centrifuged. The solid was then freeze-dried again to remove the ethanol and water, yielding 1.5 g of black PtNPs@GQDs solid product. Transmission electron microscopy revealed that ultrafine platinum nanocrystals (1.5-2 nm in diameter) were dispersed in the amorphous graphene quantum dot matrix in the form of aggregates (e.g. Figure 3 shown).

[0079] Example 6 In vitro cancer cell proliferation inhibition test

[0080] In vitro cancer cell proliferation inhibition test of PtNPs@GQDs chemotherapy drugs: After different concentrations of PtNPs@GQDs test substances were applied to human tumor cells (cell number 3K) for 3 days, the absorbance value was measured by sulforhodamine B (SRB) method, and the half-maximal inhibitory concentration IC was calculated. 50 .

[0081] Table 1 shows the IC values ​​of PtNPs@GQDs chemotherapy drugs on different human tumor cells 50 value (calculated based on platinum content, less than 0.6 μgPt / mL), indicating that PtNPs@GQDs chemotherapy drugs have a highly efficient chemotherapy effect.

[0082] Table 1. In vitro cancer cell inhibition test results of PtNPs@GQDs chemotherapy drugs

[0083]

[0084] The above descriptions are merely a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, they are not intended to limit the present application. Any technical personnel familiar with the present profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing graphene quantum dot nanosheets, characterized in that: The method comprises the following steps: S1: subjecting a mixed solution containing magnesium oxide nanosheets and a carbon source to a hydrothermal reaction to obtain graphene-coated magnesium oxide nanosheets; S2: mixing the graphene-coated magnesium oxide nanosheets and an inorganic acid solution, removing the magnesium oxide nanosheets, and then subjecting the mixture to rotary evaporation, freeze drying, and washing to obtain the graphene quantum dot nanosheets; Wherein, the carbon source is selected from at least one of ammonium citrate, diammonium hydrogen citrate, citric acid, folic acid, urea, thiourea, and dicyandiamide; The inorganic acid is selected from at least one of hydrochloric acid and sulfuric acid.

2. The method for preparing graphene quantum dot nanosheets according to claim 1, wherein: In step S1, the mass ratio of the magnesium oxide nanosheets to the carbon source is 1:0.8-1.6; Preferably, the average particle size of the magnesium oxide nanosheets is 10 to 40 nm.

3. The method for preparing graphene quantum dot nanosheets according to claim 1, wherein: In step S1, the reaction temperature of the hydrothermal reaction is 200° C. to 220° C., and the reaction time is 8 to 12 hours.

4. The method for preparing graphene quantum dot nanosheets according to claim 1, wherein: The specific process of step S1 includes: adding the carbon source and deionized water to the system in which the magnesium oxide nanosheets are dispersed to form the mixed solution, and performing the hydrothermal reaction after ultrasonically dissolving the mixed solution.

5. A graphene quantum dot nanosheet, characterized in that: The graphene quantum dot nanosheets are prepared by the preparation method according to any one of claims 1 to 4; The particle size of the graphene quantum dot nanosheets is 10nm to 40nm.

6. Use of the graphene quantum dot nanosheets according to claim 5 in the preparation of tumor diagnosis and / or cell imaging tracers, and in the preparation of photodynamic therapy or near-infrared photothermal therapy drugs.

7. The use according to claim 6, characterized in that Application of the graphene quantum dot nanosheets in the preparation of anti-tumor drug carriers.

8. A platinum nanoparticle / graphene quantum dot composite nanomaterial, characterized in that: The platinum nanoparticles are dispersed in the graphene quantum dot nanosheets in the form of aggregates; wherein the graphene quantum dot nanosheets are selected from the graphene quantum dot nanosheets according to claim 5.

9. The method for preparing the platinum nanoparticle / graphene quantum dot composite nanomaterial according to claim 8, characterized in that: include: Obtain graphene quantum dot nanosheets; thermally reduce the mixture of the graphene quantum dot nanosheets, a platinum source, and a reducing agent to obtain the platinum nanoparticle / graphene quantum dot composite nanomaterial; the graphene quantum dot nanosheets are selected from the graphene quantum dot nanosheets according to claim 5.

10. Use of the platinum nanoparticle / graphene quantum dot composite nanomaterial according to claim 8 in the preparation of anti-tumor drugs.

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