A self-triggered thermoelectric catalytic nanoparticle material, its preparation method and application

Abstract

This invention discloses a self-triggered thermoelectric catalytic nanoparticle material, its preparation method, and its application. The preparation method includes adding antimony salt, bismuth salt, tellurium salt, PVP, and sodium hydroxide solution to ethylene glycol and stirring to obtain a mixture. The mixture is then sealed and reacted at 220–240°C to obtain BST nanoparticles. The BST nanoparticles are placed in deionized water and hydrochloric acid solution is added. Then, the mixture is ultrasonicated and centrifuged to collect the precipitate. The precipitate is then washed and dispersed in deionized water to obtain a BST nanoparticle dispersion. Calcium chloride and PAA are dissolved in deionized water, and the BST nanoparticle dispersion is added dropwise under stirring and ultrasonicated. Hydrogen peroxide is added to the mixture and stirred. The mixture is then centrifuged, the precipitate is collected, and washed. The self-triggered thermoelectric catalytic nanoparticle material of this invention exhibits high specificity and strong targeting by triggering catalytic therapeutic effects in response to the tumor microenvironment.

Description

Technical Field

[0001] This invention relates to the field of biomedical engineering technology, specifically to a self-triggered thermoelectric catalytic nanoparticle material, its preparation method, and its application. Background Technology

[0002] Reactive oxygen species (ROS) regulate intracellular redox homeostasis and play a crucial role in tumorigenesis and development. Hydrogen peroxide (H₂O₂) and superoxide radicals (·O₂) are examples of reactive oxygen species. 2- Reactive oxygen species (ROS), such as hydroxyl radicals (·OH), are among the most common and effective tools for inducing apoptosis in tumor cells. ROS surge strategies, or catalytic therapies, including photocatalysis and piezoelectric catalysis, have been widely reported in the treatment of various tumors. Photocatalysis can convert light energy into chemical energy, but many factors limit its practical application. In particular, light irradiation is a prerequisite for driving the photocatalytic process. However, due to the barrier function of skin and other biological tissues, photocatalysts can only acquire very limited light energy in vivo, leading to the scarcity of photocatalytic processes. Most wide-bandgap photocatalysts can only respond to short-wavelength light, and this low light energy utilization efficiency is another limiting factor for photocatalytic therapy. Furthermore, the rapid recombination of photoexcited electron-hole pairs on the surface and in the bulk of the photocatalyst is also a significant obstacle to meeting biomedical requirements. Compared to photocatalysis, piezoelectric catalysis, based on the piezoelectric effect, can generate piezoelectric potentials, driving charge separation or transfer, triggering redox reactions, thereby converting mechanical energy into chemical energy. It also requires additional external force, such as an ultrasound generator. In addition, high-intensity or prolonged ultrasound stimulation may cause mechanical and pathological damage to normal tissues or organs.

[0003] In recent years, thermoelectric catalysis, combining the thermoelectric effect with chemical redox reactions, has been widely studied and applied in environmental remediation and energy replenishment, such as water splitting, disinfection, and the decomposition of harmful organic compounds. Unlike photocatalysis and piezoelectric catalysis, temperature fluctuations can trigger the generation of thermally generated negative and positive charges for chemical redox reactions. Temperature differences can cause slight spatial movements of atoms in the crystal structure, leading to polarization changes within the thermoelectric catalyst and induced thermoelectric charges on its surface. Temperature fluctuations mediate electron-hole pair separation, resulting in an internal electric field between the surfaces of the thermoelectric material, delaying charge recombination and ensuring corresponding catalytic activity and higher ROS generation. However, despite these significant advantages, research on ROS generation by thermoelectric catalysts remains limited. Since the thermoelectric effect is closely related to the thermoelectric voltage at a specific temperature difference, a high Seebeck coefficient of the thermoelectric material plays a crucial role in achieving efficient thermocatalytic performance. Besides thermoelectric catalysts, temperature fluctuations also need to trigger the thermoelectric effect and subsequent chemical redox reactions. Only a few biomedical applications of the thermoelectric effect have been reported, and in all these applications, the temperature fluctuations are provided by photothermal conversion via laser irradiation. This inevitably encounters the same problems as photocatalytic therapy, such as limited penetration into biological tissues and low catalytic efficiency. Therefore, developing self-triggered thermoelectric catalytic materials or systems retains the advantages of thermoelectric catalysis while avoiding its current limitations, and has great potential for clinical translation. Summary of the Invention

[0004] The purpose of this invention is to provide a self-triggered thermoelectric catalytic nanoparticle material, its preparation method, and its application. This self-triggered thermoelectric catalytic nanoparticle material does not require external excitation. It utilizes the temperature difference spontaneously generated in the tumor microenvironment to activate the thermoelectric effect. At the same time, the calcium ion-mediated ion interference method and immunotherapy in the material effectively control tumor recurrence and metastasis, solving the problems of limited penetration of light or laser into biological tissues and low catalytic efficiency in the prior art.

[0005] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0006] The first aspect of this invention provides a method for preparing self-triggered thermoelectric catalytic nanoparticle materials, the method comprising the following steps:

[0007] (a) Antimony salt, bismuth salt, tellurium salt, PVP and sodium hydroxide solution were added to ethylene glycol and stirred to obtain a mixture. The mixture was sealed and placed at 220-240℃ for reaction. After cooling, it was centrifuged and vacuum dried to obtain BST nanoparticles.

[0008] (b) BST nanoparticles were placed in deionized water and hydrochloric acid solution was added. Then, the mixture was subjected to ultrasonic and centrifugation to collect the precipitate. The precipitate was then washed and dispersed in deionized water to obtain a BST nanoparticle dispersion.

[0009] (c) Dissolve calcium chloride and PAA in deionized water, then add BST nanoparticle dispersion dropwise under stirring and sonicate; subsequently, add hydrogen peroxide to the mixture and stir, then centrifuge, collect the precipitate and wash to obtain the self-triggered thermoelectric catalytic nanoparticle material.

[0010] Preferably, in step (a), the molar ratio of antimony salt, bismuth salt and tellurium salt is 2-4:1:(5-7);

[0011] The concentration of PVP in the mixed solution is 2–5 mg / ml.

[0012] Preferably, in step (a), the volume ratio of sodium hydroxide solution to ethylene glycol is 1:(15-25);

[0013] The concentration of the sodium hydroxide solution is 4–6 mol / L.

[0014] Preferably, in step (a), the reaction time is 6 to 10 hours.

[0015] Preferably, in step (b), the mass-to-volume ratio of BST nanoparticles to deionized water is 0.8–1.25 mg / ml.

[0016] Preferably, in step (b), the volume ratio of deionized water to hydrochloric acid solution is (1-3):2; and the concentration of hydrochloric acid solution is 0.4-0.6M.

[0017] Preferably, in step (c), the mass ratio of calcium chloride to PAA is 3:(6-10); the mass-volume ratio of calcium chloride to deionized water is 12-18 mg / ml.

[0018] Preferably, in step (c), the volume ratio of BST nanoparticle dispersion to deionized water is 1:(1.5-2), and the concentration of BST nanoparticle dispersion is 0.8-1.2 mg / ml.

[0019] The amount of hydrogen peroxide added is 2% to 6% of the volume of the BST nanoparticle dispersion.

[0020] A second aspect of the present invention provides a self-triggered thermoelectric catalytic nanoparticle material prepared by the above-described preparation method.

[0021] The third aspect of this invention provides the application of the self-triggered thermoelectric catalytic nanoparticle material prepared by the above-described method in the preparation of antitumor drugs.

[0022] This invention relates to self-triggered thermoelectric catalytic nanoparticle materials for enhancing tumor catalysis / immunotherapy. Specifically, high-performance thermoelectric biomaterials, BST nanoparticles with excellent thermoelectric conversion properties, are prepared using a traditional hydrothermal method. Tumor microenvironment (TME)-responsive CaO2 nanoparticles are in situ loaded onto BST nanoparticles to synthesize BST / CaO2 nanoparticles (i.e., self-triggered thermoelectric catalytic nanoparticle materials). When the BST / CaO2 NPs material passively targets the tumor region through enhanced permeability and retention effect (EPR), the CaO2 NPs coating rapidly hydrolyzes under the stimulation of acidic TME, releasing CaO2. 2+ The process involves the release of H2O2 and a large amount of heat from the in-situ hydrolysis of CaO2 nanoparticles. This heat release induces a temperature difference on the BST nanoparticles, generating both negative and positive charges that are used in chemical redox reactions and ROS generation. Furthermore, the voltage-induced self-built-in electric field within the BST NSs can delay electron-hole recombination, thus ensuring corresponding catalytic activity and higher ROS generation. Additionally, the generated H2O2 not only further enhances oxidative stress in tumor cells and accelerates apoptosis, but also regulates the CaO2 content. 2+ Channels, slowing down Ca 2+ Outflow; in addition, the released Ca 2+ It can mediate ion interference therapy, disrupt intracellular ion homeostasis, increase the osmotic pressure of tumor cells, and effectively kill cancer cells; Ca 2+ It can effectively promote the maturation of dendritic cells and the presentation of tumor antigens, thereby activating the immune response and mediating effective immunotherapy.

[0023] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0024] The self-triggered thermoelectric catalytic nanoparticle material of this invention triggers a catalytic therapeutic effect in response to the tumor microenvironment, and has the characteristics of high specificity and strong targeting.

[0025] The self-triggered thermoelectric catalytic nanoparticle material of this invention, in which CaO2 is supported, releases H2O2 and Ca while providing a heat source. 2+ This therapy synergistically induces tumor ion interference therapy and immunotherapy. For tumor cells, CaO2, under the slightly acidic conditions of the tumor microenvironment, can generate H2O2 and calcium ions, while simultaneously releasing a large amount of heat. The heat released from the in-situ hydrolysis of CaO2 nanoparticles causes a temperature difference on the BST nanoparticles, generating heat-generated negative and positive charges, which are used for chemical redox reactions and ROS generation. The generated H2O2 oxidatively damages tumor cells and closes calcium ion channels. The calcium ions released by CaO2 accumulate in large quantities within tumor cells, thereby mediating ion interference therapy to kill tumor cells. After tumor cell death, calcium ions are released, and Ca...2+ It can effectively promote the maturation of dendritic cells and the presentation of tumor antigens, thereby activating the immune response and mediating effective immunotherapy.

[0026] The unique tumor microenvironment responsiveness of this invention has no catalytic activity on normal cells and has excellent biosafety. For normal cells, calcium peroxide reacts with water in vivo to release calcium ions and oxygen. The released calcium ions are discharged from the cell through calcium ion channels, without any toxic side effects in vivo. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0028] Figure 1 The results of thermoelectric performance testing of BST nanoparticles prepared in Example 1 of this invention;

[0029] Figure 2 The thermoelectric performance test results of the BST nanoparticles prepared in Example 2 of this invention are shown.

[0030] Figure 3 This is a SEM image of the self-triggered thermoelectric catalytic nanoparticle material prepared in Example 4 of this invention;

[0031] Figure 4 This is a laser particle size analysis diagram of the self-triggered thermoelectric catalytic nanoparticle material prepared in Example 4 of the present invention.

[0032] Figure 5 The degradation of DPBF under different conditions in Example 4 of this invention;

[0033] Figure 6 The results of the in vitro toxicity study of BST NPs, CaO2 NPs, and BST / CaO2 NPs on two cell types in Example 5 of this invention are as follows;

[0034] Figure 7 The effects of BST NPs, CaO2 NPs, and BST / CaO2 NPs on tumor size in vivo in Example 5 of this invention;

[0035] Figure 8 The results of flow cytometry detection in Example 5 of this invention;

[0036] Figure 9 These are the test results of various indicators in the biosafety test in Example 6 of the present invention. Detailed Implementation

[0037] The embodiments of the technical solution of the present invention will be described in detail below with reference to the examples. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and are therefore only examples, and should not be used to limit the scope of protection of the present invention.

[0038] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by those skilled in the art to which this invention pertains.

[0039] Example 1

[0040] This embodiment describes a method for preparing BST nanoparticles, which includes the following steps:

[0041] Add 3 mmol SbCl3, 1 mmol Bi(NO3)3·5H2O, 6 mmol Na2TeO3, 2 mL NaOH solution (5 mol / L), and 100 mg PVP to 40 mL ethylene glycol;

[0042] The homogeneous solution was then transferred, stirred vigorously for 30 minutes, and then placed into a 100 mL muffle furnace reaction vessel and sealed. It was then placed in a microwave oven at 230 °C for 8 hours. After cooling, the solution was washed, centrifuged, and dried in a vacuum oven at 60 °C for 12 hours to obtain BST nanoparticles.

[0043] The thermoelectric properties of the BST nanoparticles (25℃ and 50℃) and deionized water (control group, 25℃) prepared above were tested, and the results are as follows: Figure 1 As shown, Figure 1 The rightmost image shows the test results at 50℃;

[0044] Depend on Figure 1 It can be seen that the BST nanoparticles prepared in Example 1 have a certain degradation effect on DPBF compared with the control group when a temperature difference is applied, which confirms the thermoelectric catalytic effect of the prepared material.

[0045] Example 2

[0046] This embodiment describes a method for preparing BST nanoparticles, which includes the following steps:

[0047] Add 1.5 mmol SbCl3, 0.5 mmol Bi(NO3)3·5H2O, 3 mmol Na2TeO3, 2 mL NaOH solution (5 mol / L), and 200 mg PVP to 40 mL ethylene glycol;

[0048] The homogeneous solution was then transferred, stirred vigorously for 30 minutes, and then placed into a 100 mL muffle furnace reaction vessel and sealed. It was then placed in a microwave oven at 230 °C for 8 hours. After cooling, the solution was washed, centrifuged, and dried in a vacuum oven at 60 °C for 12 hours to obtain BST nanoparticles.

[0049] The thermoelectric properties of the BST nanoparticles (25℃ and 50℃) and deionized water (control group, 25℃) prepared above were tested, and the results are as follows: Figure 2 As shown, Figure 2 The rightmost image shows the test results at 50℃;

[0050] Depend on Figure 2 It can be seen that the BST nanoparticles prepared in Example 2 have a better degradation effect on DPBF than those in Example 1 under the condition of applying a temperature difference, and the catalytic effect is better, which confirms the superiority of the raw material ratio. Therefore, we finally chose the synthesis method of Example 2.

[0051] Example 3

[0052] This embodiment describes a method for preparing self-triggered thermoelectric catalytic nanoparticle materials, which includes the following steps:

[0053] (a) Immerse 5 mg of BST nanoparticles prepared in Example 2 into 5 mL of deionized water; then, add 2 mL of 0.5 M HCl solution to the above solution, sonicate for 10 min, and then centrifuge at 15000 rpm for 5 min; disperse the precipitate in deionized water, centrifuge and wash 3 times; then disperse the collected nanoparticles in deionized water to obtain BST nanoparticle dispersion.

[0054] (b) Dissolve 150 mg CaCl2 and 400 mg PAA in 10 mL of deionized water, and then add 5 mL of the above BST nanoparticle dispersion (1 mg / mL) while stirring. After sonication for 30 min, add 200 μL H2O2 to the solution, stir for 30 min, and collect BST / CaO2 NSs by centrifugation at 15000 rpm for 5 min. Wash with deionized water 3 times to obtain the self-triggered thermoelectric catalytic nanoparticle material (denoted as BST / CaO2).

[0055] Example 4

[0056] This embodiment characterizes the structure and properties of the self-triggered thermoelectric catalytic nanoparticle material prepared in Example 3:

[0057] (1) Structural characterization: The structure of BST / CaO2 was characterized using scanning electron microscopy (SEM) and laser particle size analyzer, respectively; the results of electron microscopy are shown below. Figure 3As shown, the laser particle size analyzer test results are as follows: Figure 4 As shown;

[0058] Depend on Figure 3 , Figure 4 It can be seen that the self-triggered thermoelectric catalytic nanoparticle material is hexagonal with an average particle size of 110 nm.

[0059] (2) Performance Characterization: The thermoelectric properties of the self-triggered thermoelectric catalytic nanoparticle material (BST / CaO2) were studied. Since CaO2 exothermically activates the thermoelectric properties of the material in the acidic environment of the tumor microenvironment, we used the ROS probe 1,3-diphenylisobenzofuran (DPBF) to determine the formation of ·O2 by BST / CaO2 at different pH values. 2- The ability to detect BST / CaO2 at a concentration of 0.1 mg / mL was studied. BST / CaO2 suspensions were dispersed in PBS solutions (pH 5.5 and pH 7.4, 25°C) and mixed with DPBF (2 mg / mL, 150 μL). Suspensions of 0.1 mg / mL BST NSs and CaO2 NPs were dispersed in PBS solutions (pH 7.4, 25°C) and mixed with DPBF (2 mg / mL, 150 μL). The mixtures were then stirred, and the absorbance of the solutions was measured after different time periods. The degradation of DPBF was investigated. 2- The generation; the detection results are as follows Figure 5 As shown;

[0060] Depend on Figure 5 It was found that BST NSs, CaO2 NPs, and BST / CaO2 in PBS (pH 7.4) showed similar results to the control group, with almost no ROS generation in the absence of temperature difference. This phenomenon not only demonstrates the thermoelectric catalysis mechanism but also proves the high biosafety of our prepared thermoelectric catalyst. When BST NSs were incubated in a constant temperature environment of 25℃–45℃, significant ROS generation was observed, indicating that the thermoelectric effect was triggered in BST NSs due to the temperature difference. However, in the BST / CaO2 group in PBS (pH 5.5), DPBF degradation was more pronounced and rapid. This confirms that CaO2 NPs are relatively stable in a neutral environment but undergo vigorous hydrolysis in a low pH environment. The hydrolysis of CaO2 nanoparticles releases a large amount of heat, thereby activating the BST thermoelectric catalysis.

[0061] Example 5

[0062] This example demonstrates the in vitro antitumor effect of the self-triggered thermoelectric catalytic nanoparticle material prepared in Example 3:

[0063] CT26 and TE1 cells were seeded in 96-well plates and cultured for 24 hours (37°C, 5% CO2). Then, different concentrations of BST NSs, CaO2 NPs, and BST / CaO2 (0 mg / mL, 0.05 mg / mL, 0.1 mg / mL, 0.15 mg / mL, 0.2 mg / mL) were mixed into the culture medium. After co-culturing for 24 hours, CCK8 assay was performed to determine cell viability. The results are shown below. Figure 6 As shown;

[0064] Depend on Figure 6 It can be seen that the cytotoxic effect of BST nanoparticles is negligible, while due to Ca... 2+ Overloading and rapid hydrolysis of CaO2 nanoparticles in an acidic environment induced H2O2 oxidative stress, leading to specific cytotoxic effects of CaO2 nanoparticles on cancer cells CT26 and TE1. Simultaneously, BST / CaO2 was observed to exhibit the strongest cytotoxic effect on tumor cells. Treatment with BST / CaO2 (200 g / mL) resulted in the death of over 80% of tumor cells. BST / CaO2 nanoparticles demonstrate excellent killing activity against cancer cells and exhibit strong in vitro antitumor properties.

[0065] Example 6

[0066] This example demonstrates the in vivo antitumor effect of the self-triggered thermoelectric catalytic nanoparticle material prepared in Example 3:

[0067] Will contain 2×10 6 100 μL of serum-free cell culture medium containing 1 CT26 cells was injected subcutaneously into Balb / c mice (female, 6 weeks old, weighing 14–16 g) to establish a subcutaneous xenograft model in nude mice. When the tumor size reached 80 mm... 3 At approximately 10:00 AM, CT26 tumor-bearing mice were randomly divided into four groups: PBS group, BST NPs group, CaO2 NPs group, and BST / CaO2 NPs group, with five mice in each group. NSs were administered intravenously at 5 mg / kg. During treatment, the body weight and tumor size of each group were measured and recorded every two days using calipers and a digital scale. Tumor volume was calculated using the formula: Tumor volume = (length × width) / (length × width) 2 ) / 2. The calculation result is as follows: Figure 7 As shown;

[0068] Depend on Figure 7 It was found that the tumor volume of mice in the PBS group increased rapidly and continuously within two weeks. Because BST NSs lack thermoelectric effects at a constant temperature, the BST group showed almost no significant tumor growth inhibition compared to the control group (PBS), and all mice in the BST group died on day ten. The application of CaO2 NPs alone had a certain degree of inhibitory effect on mouse tumor growth, which is due to the decomposition of CaO2 in the TME, releasing H2O2 and Ca.2+ This can cause oxidative damage to cancer cells, potentially leading to ion interference therapy; specifically, H2O2 can interfere with calcium ion channels, increasing intracellular calcium levels in tumor cells. 2+ Concentration increases cell osmotic pressure, leading to significant absorption and expansion; furthermore, Ca... 2+ It can effectively promote the maturation and migration of dendritic cells (DCs) and enhance antigen presentation capabilities, thereby enhancing tumor immunotherapy. The therapeutic effect of BST / CaO2 treatment is superior to that of CaO2, indicating that the heat released from the decomposition of CaO2 in the TME activates the thermoelectric effect of BST, leading to thermoelectric catalysis. Due to the synergistic thermoelectric and immunomodulatory effects of BST / CaO2 NSs, the BST / CaO2 group has the greatest inhibitory effect on tumor growth.

[0069] Tumors from treated mice were collected and analyzed by flow cytometry to assess dendritic cell (DC) maturation and migration to lymph nodes. Experimental results are as follows: Figure 8 As shown:

[0070] Depend on Figure 8 It can be seen that, compared with the control group, the CaO2 NPs group and the BST / CaO2 NSs group had more mature DCs (CD80). + CD86 + The number of [certain substances] increased by 3.8 times and 4.1 times, respectively. The number of mature DCs in the BST group showed no significant change, indicating that the released Ca [mathematical activity]... 2+ This is likely the most important factor triggering dendritic (DC) maturation. Further examination and analysis were conducted on the migration of mature DCs to lymph nodes. The number of mature DCs in the lymph nodes of the CaO2 NPs group was 1.3 times that of the control group. The BST / CaO2 NSs group had the highest number of mature DCs in the lymph nodes, 1.9 times that of the control group. These results confirm that BST / CaO2 NSs has a good immunomodulatory effect.

[0071] Example 7

[0072] This example demonstrates the in vivo biosafety testing of the self-triggered thermoelectric catalytic nanoparticle material prepared in Example 3:

[0073] Healthy female Balb / c mice (7 weeks old, 16–18 g) were intravenously injected with BST / CaO2 NSs (10 mg / kg). 24 hours after injection, complete blood counts were measured, including white blood cells (WBC), red blood cells (RBC), platelets (PLT), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular hemoglobin concentration (MCH), hemoglobin (HGB), and hematocrit (HCT). Serum biochemical parameters were also measured, including gamma-glutamyl transferase (γ-GT), total protein (TP), lactate dehydrogenase (LDH), C-reactive protein (CRP), creatine kinase (CK), creatinine (Cr), and blood urea nitrogen (BUN). Alanine, aspartate aminotransferase (AST), amylase (AMY), aminotransferase (ALT), and albumin (ALB) levels were measured and compared with a control group to evaluate the biocompatibility of BST / CaO2 NSs. Results are shown below. Figure 9 As shown;

[0074] Depend on Figure 9 It can be seen that the self-triggered thermoelectric catalytic nanoparticle material involved in this invention has good biosafety.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for preparing self-triggered thermoelectric catalytic nanoparticle materials, characterized in that, Includes the following steps: (a) Antimony salt, bismuth salt, tellurium salt, PVP and sodium hydroxide solution are added to ethylene glycol and stirred to obtain a mixture. The mixture is sealed and placed at 220-240℃ for reaction. After cooling, it is centrifuged and vacuum dried to obtain BST nanoparticles. The antimony salt is SbCl3, the bismuth salt is Bi(NO3)3·5H2O, and the tellurium salt is Na2TeO3. (b) BST nanoparticles were placed in deionized water and hydrochloric acid solution was added. Then, the mixture was subjected to ultrasonic and centrifugation to collect the precipitate. The precipitate was then washed and dispersed in deionized water to obtain a BST nanoparticle dispersion. (c) Dissolve calcium chloride and PAA in deionized water, then add BST nanoparticle dispersion dropwise under stirring and sonicate; subsequently, add hydrogen peroxide to the mixture and stir, then centrifuge, collect the precipitate and wash to obtain the self-triggered thermoelectric catalytic nanoparticle material. In step (a), the molar ratio of antimony salt, bismuth salt and tellurium salt is (2-4):1:(5-7); The concentration of PVP in the mixed solution is 2–5 mg / ml.

2. The preparation method according to claim 1, characterized in that, In step (a), the volume ratio of sodium hydroxide solution to ethylene glycol is 1:(15-25); The concentration of the sodium hydroxide solution is 4–6 mol / L.

3. The preparation method according to claim 1, characterized in that, In step (a), the reaction time is 6 to 10 hours.

4. The preparation method according to claim 1, characterized in that, In step (b), the mass-to-volume ratio of BST nanoparticles to deionized water is 0.8–1.25 mg / ml.

5. The preparation method according to claim 1, characterized in that, In step (b), the volume ratio of deionized water to hydrochloric acid solution is (1-3):2; the concentration of hydrochloric acid solution is 0.4-0.6M.

6. The preparation method according to claim 1, characterized in that, In step (c), the mass ratio of calcium chloride to PAA is 3:(6-10); the mass-volume ratio of calcium chloride to deionized water is 12-18 mg / ml.

7. The preparation method according to claim 1, characterized in that, In step (c), the volume ratio of BST nanoparticle dispersion to deionized water is 1:(1.5-2), and the concentration of BST nanoparticle dispersion is 0.8-1.2 mg / ml. The amount of hydrogen peroxide added is 2% to 6% of the volume of the BST nanoparticle dispersion.

8. The self-triggered thermoelectric catalytic nanoparticle material prepared by any one of the preparation methods described in claims 1 to 7.

9. The application of the self-triggered thermoelectric catalytic nanoparticle material prepared by any one of claims 1 to 7 in the preparation of antitumor drugs.

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