Heterojunction nano-enzyme as well as preparation method and application thereof

Abstract

The preparation method comprises the following steps: firstly synthesizing cubic Co3O4 (PCC NPs) through a hydrothermal method, changing the molar ratio of the cubic Co3O4 (PCC NPs) to a zinc source and a cadmium source, and synthesizing a series of heterojunction nano enzymes under the conditions of high temperature and high pressure. The novel PCC-coated ZnCdS heterojunction nano-enzyme is designed and prepared, the proportion of Co < 2 + > / Co < 3 + > in the material is successfully increased, and the ROS removal capacity is remarkably enhanced. The PCC-coated ZnCdS heterojunction shows good multi-enzyme activity like superoxide dismutase (SOD), glutathione peroxidase (GSH-GPx), catalase (CAT) and the like, maximization of antioxidant activity is achieved, the material can release endogenous H2S, inhibit release of inflammatory factors and inhibit activation of NLRP3 inflammasomes, and a new strategy is provided for treatment of colitis.

Description

Technical Field

[0001] This invention belongs to the field of nanomedicine technology, specifically relating to a heterojunction nanozyme, its preparation method, and its application. Background Technology

[0002] Reactive oxygen species (ROS) include singlet oxygen (… 1 O2), hydrogen peroxide (H2O2), hydroxyl radicals (·OH), and superoxide anions (O2). ·- Excessive ROS production disrupts redox homeostasis, leading to lipid peroxidation, protein and DNA damage, and consequently triggering various inflammatory diseases. Oxidative stress-induced excessive ROS production plays a crucial role in the pathogenesis of ulcerative colitis (UC), exacerbating colonic inflammation. Therefore, inhibiting oxidative stress by clearing excess ROS is essential for UC treatment.

[0003] Nanozymes with intrinsic enzyme-like activity have attracted much attention due to their multifunctionality, ease of preparation, and tunability. In particular, noble metal nanozymes, metal oxides, metal-organic frameworks (MOFs), and carbon-based materials exhibit a variety of enzyme-mimicking activities. Nanozymes with activities similar to superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) have been used to eliminate reactive oxygen species (ROS) for cell protection, anti-inflammatory, or anti-cancer therapeutic diagnostics. Currently synthesized Gel@Co3O4@TGP combines gastric acid protection, colon targeting, ROS scavenging, and natural anti-inflammatory properties, offering significant advantages such as convenient oral administration, high safety, and synergistic effects. However, key bottlenecks such as release precision and drug loading still need to be addressed. In this invention, by regulating Co3O4Co… 2+ / Co 3+ The ratio can optimize the electronic structure of the catalytic center, providing a new approach for developing highly efficient ROS-removing metal oxide materials.

[0004] The NLRP3 inflammasome, a key member of the NOD-like receptor family, plays a crucial role in inflammatory and immune responses by primarily activating Caspase-1 to promote the maturation and secretion of interleukin-1β (IL-1β) and IL-18. Studies have shown that ROS is an upstream factor in NLRP3 inflammasome activation, and the NLRP3 inflammasome plays an important role in colitis. Furthermore, H2S has been shown to modulate inflammatory responses, and its synthesis increases under pro-inflammatory conditions. There is evidence that supplementing with H2S donors may be beneficial in inhibiting NLRP3 inflammasome activation. In addition, there are reports that H2S alleviates colitis inflammation by inhibiting nuclear factor-κB (NF-κB) pathway activation or by exerting its antioxidant and immunomodulatory effects. Summary of the Invention

[0005] Objective of the Invention: To address the problems existing in the prior art, this invention provides a heterojunction nanozyme. By constructing a PCC@ZnCdS heterojunction nanozyme, this invention successfully increases the Co content in the material. 2+ / Co 3+ The PCC@ZnCdS heterojunction nanozyme constructed in this invention significantly enhances ROS scavenging ability. It exhibits excellent multi-enzyme activities, including superoxide dismutase (SOD), glutathione peroxidase (GSH-GPx), and catalase (CAT), maximizing antioxidant activity. Mechanistic studies show that this material can release endogenous H2S, inhibit the release of inflammatory factors, and suppress NLRP3 inflammasome activation. The combination of these two factors not only scavenges existing ROS but also blocks the continuous generation of ROS, inhibiting ROS production at its source and alleviating inflammation.

[0006] The present invention also provides a method for preparing the heterojunction nanozyme and its application.

[0007] Technical solution: In order to achieve the above objectives, the present invention provides a heterojunction nanozyme by first synthesizing cubic Co3O4 (PCC NPs) via a hydrothermal method, changing its molar ratio with zinc and cadmium sources, and then synthesizing a series of heterojunction nanozymes under high temperature and high pressure conditions.

[0008] The heterojunction nanozyme has a cubic structure with nanospheres uniformly growing around the cube, and the size is about 230-270 nm.

[0009] The preparation method of the heterojunction nanozyme of the present invention includes the following steps:

[0010] (1) Dissolve Co(NO3)2·6H2O and NaOH in deionized water respectively. Add NaOH solution dropwise to Co(NO3)2 solution while stirring. After continuous stirring, carry out hydrothermal reaction of the mixed solution to obtain the precursor. Calcine the dried precursor to obtain the target product PCC NPs.

[0011] (2) Dissolve Zn(Ac)2·2H2O and Cd(Ac)2·2H2O in deionized water, sonicate, add thioacetamide (TAA), and stir continuously. Dissolve NaOH in deionized water and pour it into the above solution. Stir continuously. After stirring, wash and dry the sample obtained by high temperature reaction of the mixture to finally obtain ZnCdS NPs.

[0012] (3) Dissolve PCC NPs in deionized water and sonicate to obtain product A; dissolve Zn(Ac)2·2H2O and Cd(Ac)2·2H2O in deionized water and sonicate to obtain product B; add solution B to solution A, add TAA while stirring, and sonicate to obtain product C;

[0013] (4) Add NaOH solution to product C, stir thoroughly, and react at high temperature until the product PCC@ZnCdS NPs is obtained.

[0014] Preferably, (1) firstly, Co(NO3)2⋅6H2O and NaOH are dissolved in deionized water to form red and colorless transparent solutions, respectively. Subsequently, at room temperature (25°C), the NaOH solution is added dropwise to the Co(NO3)2 solution while stirring, and after continuous stirring, a dark green viscous liquid is obtained. The mixed solution is transferred to a hydrothermal reactor lined with polytetrafluoroethylene and placed in a temperature-controlled oven for high-temperature reaction. After the obtained product is dried in a vacuum drying oven, the dried precursor is finally calcined in a muffle furnace to obtain the target product PCC NPs.

[0015] (2) Dissolve Zn(Ac)₂·2H₂O and Cd(Ac)₂·2H₂O in deionized water and sonicate until the solution is clear and transparent. Add thioacetamide (TAA) rapidly while stirring vigorously. Dissolve NaOH in deionized water and pour it into the above solution while stirring continuously. After stirring, pour the mixture into a reaction vessel and react at high temperature. Wash the obtained sample three times and vacuum dry overnight at 60°C to finally obtain spherical ZnCdS NPs, abbreviated as ZCS NPs.

[0016] (3) Dissolve PCC NPs in deionized water and sonicate to obtain product A; dissolve Zn(Ac)2·2H2O and Cd(Ac)2·2H2O in deionized water and sonicate to obtain product B; add solution B to solution A and stir. Add TAA rapidly under vigorous stirring, sonicate until completely dissolved, and then stir to obtain product C.

[0017] (4) Add NaOH solution to product C, stir thoroughly, transfer to a reactor for high-temperature reaction, centrifuge and wash to obtain product PCC@ZnCdS NPs. During this process, PCC@ZnCdS NPs with different molar ratios were prepared according to the input molar ratio. Keeping the molar amounts of Zn(Ac)2·2H2O and Cd(Ac)2·2H2O constant, the molar amount of added PCC NPs was changed to obtain seven samples: PZ-0.5, PZ-1.0, PZ-1.5, PZ-2.0, PZ-2.5, PZ-3.0, and PZ-8.0 NPs.

[0018] In step (1), the molar ratio of NaOH to Co(NO3)2⋅6H2O is 1~6:1~1.

[0019] Preferably, the molar ratio of NaOH to Co(NO3)2·6H2O is 1:1, and the calcination temperature and time in the muffle furnace are 500℃ for 2 hours.

[0020] In step (2), the molar ratio of Zn(Ac)2·2H2O and Cd(Ac)2·2H2O is 1~2:1~1; the molar ratio of Cd(Ac)2·2H2O and TAA in step (2) is 1~5:1~2.

[0021] In step (3), the molar ratio of PCC NPs to TAA is 1~5:1~2.

[0022] In step (4), the temperature of the hydrothermal reaction is 120℃~180℃ and the time is 10 h~48 h.

[0023] In step (4), PCC@ZnCdS NPs with different proportions were prepared according to the molar ratio of input. The molar amounts of Zn(Ac)2·2H2O and Cd(Ac)2·2H2O were kept constant, and the molar amount of added PCC NPs was changed to obtain seven samples: PZ-0.5, PZ-1.0, PZ-1.5, PZ-2.0, PZ-2.5, PZ-3.0, and PZ-8.0 NPs.

[0024] The application of the heterojunction nanozyme described in this invention in the preparation of anti-inflammatory reagents or drugs.

[0025] The anti-inflammatory treatments mentioned include chronic diseases such as ulcerative colitis and atherosclerosis.

[0026] Furthermore, the novel PCC@ZnCdS heterojunction nanozyme exhibits excellent multi-enzyme activities, including superoxide dismutase (SOD), glutathione peroxidase (GSH-GPx), and catalase (CAT), maximizing its antioxidant activity and providing a new strategy for the treatment of colitis.

[0027] This invention designs and prepares a novel PCC@ZnCdS heterojunction nanozyme. The nanoparticles exhibit a cubic structure with uniformly grown nanospheres around the cube, each approximately 250 nm in size. These nanoparticles demonstrate excellent multi-enzyme activities, including superoxide dismutase (SOD), glutathione peroxidase (GSH-GPx), and catalase (CAT), maximizing antioxidant activity. This invention first synthesizes cubic Co3O4 (PCC NPs) via a hydrothermal method. By varying the molar ratio of PCC to zinc and cadmium sources, a series of PCC@ZnCdS nanomaterials with different proportions are synthesized under high temperature and high pressure conditions. The optimal feed ratio is determined through electron microscopy and in vitro performance characterization, constructing a PZ-2.5 NPs heterojunction material. The material constructed in this invention has a cubic structure with uniformly grown nanospheres around the cube, each approximately 250 nm in size. This invention successfully increases the Co content in the material. 2+ / Co 3+ The ratio of [specific enzymes] significantly enhanced the ROS scavenging ability. Experiments revealed that PZ-2.5 NPs heteroknots exhibited excellent multi-enzyme activities, including superoxide dismutase (SOD), glutathione peroxidase (GSH-GPx), and catalase (CAT), maximizing antioxidant activity and providing a new strategy for the treatment of colitis.

[0028] Compared to natural enzymes, most metal oxide-based ROS scavenging materials exhibit poor catalytic activity. Their highly oxidized metal centers deteriorate redox properties, limiting their applications. The PCC@ZnCdS heterojunction prepared in this invention can modulate Co... 2+ / Co 3+ The ratio was optimized to improve the electronic structure of the catalytic center, which significantly improved the ROS removal capacity.

[0029] Studies have shown that ROS is an upstream factor for NLRP3 inflammasome activation, and the NLRP3 inflammasome plays an important role in colitis. Furthermore, H2S has been shown to modulate inflammatory responses, and its synthesis increases under pro-inflammatory conditions. There is evidence that supplementing with H2S donors may be beneficial in inhibiting NLRP3 inflammasome activation. In addition, there are reports that H2S alleviates colitis inflammation by inhibiting nuclear factor-κB (NF-κB) pathway activation or by exerting its antioxidant and immunomodulatory effects. The PCC@ZnCdS heterojunction material prepared in this invention can release endogenous H2S, inhibit the release of inflammatory factors, and suppress NLRP3 inflammasome activation.

[0030] This invention designs and prepares a novel PCC@ZnCdS heterojunction nanozyme, systematically studies its ROS scavenging performance and multi-enzyme activity, and explores its application potential in the treatment of colitis. By constructing the PCC@ZnCdS heterojunction material, the Co content in the material was successfully increased. 2+ / Co 3+ The proportion of [specific ingredient] significantly enhances ROS scavenging ability. Exploration revealed that PCC@ZnCdS heteroknots exhibit excellent multi-enzyme activities, including superoxide dismutase (SOD), glutathione peroxidase (GSH-GPx), and catalase (CAT), maximizing antioxidant activity. Mechanistic studies showed that this material can release endogenous H2S, inhibit the release of inflammatory factors, and suppress NLRP3 inflammasome activation. The combination of these two factors simultaneously scavenges existing ROS while blocking the continuous generation of ROS, inhibiting ROS production at its source. This unique dual-action mechanism not only achieves a synergistic effect of anti-inflammation and anti-oxidation but also promotes the transformation of macrophages from M1 to M2 types, providing a new strategy for the treatment of colitis. This invention highlights the potential biological effects of heteroknots in the treatment of inflammation, providing important insights into their application in anti-inflammatory strategies.

[0031] Compared to natural enzymes, most metal oxide-based ROS scavenging materials exhibit poor catalytic activity, and their highly oxidized metal centers deteriorate redox properties, limiting their applications. The PCC@ZnCdS heterojunction prepared in this invention can modulate Co... 2+ / Co 3+ The ratio was optimized to improve the electronic structure of the catalytic center, which significantly improved the ROS removal capacity.

[0032] For ulcerative colitis, the PCC@ZCS NPs heterojunction nanozyme material developed in this invention exhibits excellent performance. This invention enhances Co content by precisely controlling the ratio of PCC to ZCS. 2+ / Co 3+ The obtained PZ-2.5 NPs exhibit good dispersibility, stability, and multi-enzyme activity. They can efficiently scavenge ROS and release O2, significantly improving the inflammatory hypoxic microenvironment. Intracellularly, by clearing existing ROS, releasing H2S, activating mitophagy, inhibiting the NF-κB signaling pathway, and suppressing the NLRP3 inflammasome, they fundamentally cut off ROS production, achieving synergistic anti-inflammatory and antioxidant therapy, providing a novel material and strategy for the treatment of ulcerative colitis. This invention experimentally verifies the anti-inflammatory and antioxidant capabilities of PZ-2.5 NPs at the cellular level, inhibiting the secretion of inflammatory factors, promoting macrophage transformation, and inhibiting NLRP3 inflammasome activation.

[0033] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0034] This invention designs and prepares a novel PCC@ZnCdS heterojunction nanozyme, which possesses multi-enzyme activity (catalase, superoxide dismutase, and glutathione peroxidase). It releases oxygen to alleviate the hypoxic microenvironment, clears existing reactive oxygen species in the diseased environment, inhibits NF-κB, and simultaneously releases hydrogen sulfide to inhibit the mitochondrial respiratory chain, thereby achieving mitophagy and cutting off the production of reactive oxygen species at the source. Through these two steps, it simultaneously inhibits NLRP3 activation and suppresses the release of inflammatory factors, achieving the transformation of macrophages from M1 to M2 types. This "two-pronged approach" of anti-inflammatory and antioxidant treatment is used to treat colon inflammation. Attached Figure Description

[0035] Figure 1 Transmission electron microscopy (TEM) images of PCC NPs, ZnCdS NPs, and PZ NPs produced by different feed ratios of the two.

[0036] Figure 2 A is a high-magnification transmission electron microscope image of PZ-2.5 NPs; Figure 2 B represents the lattice fringes of PZ-2.5 NPs.

[0037] Figure 3 EDS Mapping diagram for PZ-2.5 NPs.

[0038] Figure 4 Zeta potentials of different materials (data are expressed as average ± SD (n = 3)); Figure 4 Stability analysis of 30 μg mL⁻¹ PZ-2.5NPs (B) and the variation of hydrated particle size in different solvents (n = 3, mean ± SD). Figure 4 C is the corresponding digital photograph (from left to right: ultrapure water, high glucose medium (DMEM), phosphate buffer solution (PBS), culture medium (high glucose medium + 10% bovine serum (FBS)).

[0039] Figure 5 X-ray photoelectron spectroscopy (XPS) of PZ-2.5 NPs: (A) Total spectrum; (B) Co 2p; (C) O 1s; (D) Zn 2p; (E) Cd 3d; (F) S 2p.

[0040] Figure 6 A represents the electrochemical impedance spectroscopy (EIS) of PCC, ZnCdS, and PZ-2.5 NPs in a 5 mM K3[Fe(CN)6] / K4[Fe(CN)6] electrolyte. Figure 6 B-cycle voltammetry (CV).

[0041] Figure 7A is 100 μg / mL -1 Digital photographs of the reaction of the supernatant with TiSO4 after different reagents (H2O, PCC, ZCS, PZ-0.5, PZ-1.0, PZ-1.5, PZ-2.0, PZ-2.5, PZ-3.0, PZ-8.0 NPs) reacted with hydrogen peroxide (H2O2) for 12 h. Figure 7 B is the correct answer. Figure 7 UV-vis spectrum of solution A for detection; Figure 7 C represents the H2O2 scavenging rate of different reagents (mean ± SD, n = 2).

[0042] Figure 8 The fluorescence difference of RDPP + H2O2 + different reagents under different treatments (0-30 min).

[0043] Figure 9 A shows photographs of different reagents reacting with H2O2 / FeSO4 solution, followed by the addition of TMB for stabilization. Figure 9 B is the UV-vis image obtained from the detection of solution 9A.

[0044] Figure 10 Different concentrations of A, 10B, and 10C (0, 60, 80, 100, 150 μg / mL) -1 PCC, ZCS and PZ-2.5 NPs · O2 - The inhibition rate.

[0045] Figure 11 A UV-viscosity of GSH oxidation catalyzed by different reagents; Figure 11 Different concentrations of B, 11C, and 11D (0, 60, 80, 100, 150 μg / mL) -1 UV-vis images of GSH catalyzed by PCC, ZCS and PZ-2.5 NPs.

[0046] Figure 12 A represents the UV absorption spectra of ABTS radicals with different reagents (PCC, ZCS, PZ-2.5 NPs); Figure 12 B, 12C, and 12D represent different concentrations (0, 20, 40, 60, 80, 100 μg / mL), respectively. -1 UV absorption spectra of PZ-2.5, PCC and ZCS NPs ABTS free radicals.

[0047] Figure 13 A represents the UV absorption spectra of DPPH radicals from different reagents (PCC, ZCS, PZ-2.5 NPs); Figure 13B, 13C, and 13D at different concentrations (0, 20, 40, 60, 80, 100 μg / mL) -1 UV absorption spectra of PZ-2.5, PCC and ZCS NPs DPPH radicals.

[0048] Figure 14 A, 14B, 14C, 14D, and 14E represent different concentrations (0-90 μg / mL). -1 Cell viability assessment of L02 cells, HUVEC cells, RAW 264.7 cells, IEC-6 cells, and Caco-2 cells using substances (PCC, ZCS, PZ-2.5NPs) (n=3, mean ± SD). Figure 14 F represents the in vitro hemolysis assay of PZ-2.5 NPs (n = 3, mean ± SD).

[0049] Figure 15 The intracellular H2O2 content of RAW 264.7 cells after LPS stimulation under different treatments (n = 3, mean ± SD). Statistical significance was calculated using one-way ANOVA. p<0.001; Figure 15 B represents the survival rate of RAW 264.7 cells after LPS stimulation under different treatments (n = 3, mean ± SD). Figure 15 C represents the survival rate of RAW 264.7 cells stimulated with LPS after treatment with different concentrations of PZ-2.5 NPs (n = 3, mean ± SD). Figure 15 D represents the intracellular H2O2 content in Caco-2 cells after LPS stimulation under different treatments (n = 3, mean ± SD). Statistical significance was calculated using one-way ANOVA. p<0.001; Figure 15 E represents the survival rate of Caco-2 cells after LPS stimulation under different treatments (n = 3, mean ± SD). Figure 15 F represents the survival rate of Caco-2 cells stimulated with LPS after treatment with different concentrations of PZ-2.5 NPs (n = 3, mean ± SD).

[0050] Figure 16 A shows the CLSM plot of RDPP in RAW 264.7 cells under different treatments (scale bar: 100 μm). Figure 16 B Figure 16 RDPP fluorescence quantitative analysis of A (n = 3, mean ± SD). Statistical significance was calculated by one-way ANOVA, where ns indicates no statistical difference. p < 0.001; Figure 16C represents the intracellular HIF-1α content in RAW 264.7 cells under different conditions (n ​​= 3, mean ± SD). Statistical significance was calculated using one-way ANOVA. p<0.01; p<0.001.

[0051] Figure 17 A shows the CLSM map of CD86 in RAW 264.7 cells under different treatments (scale bar: 40 μm). Figure 17 B is the correct answer. Figure 17 CD86 fluorescence quantitative analysis of A (n = 3, mean ± SD). Statistical significance was calculated by one-way ANOVA. p<0.001; Figure 17 C is a CLSM map of CD206 in RAW 264.7 cells under different treatments (scale bar: 100 μm). Figure 17 D is the correct answer. Figure 17 Quantitative analysis of CD206 fluorescence in C (n = 3, mean ± SD). Statistical significance was calculated by one-way ANOVA, where ns indicates no significant difference. p<0.01, p<0.001.

[0052] Figure 18 A represents the intracellular ATP content of RAW 264.7 cells under different treatments (n = 3, mean ± SD). Statistical significance was calculated using one-way ANOVA. p<0.001; Figure 18 B represents the intracellular H2S content in RAW 264.7 cells under different conditions (n ​​= 3, mean ± SD). Statistical significance was calculated using one-way ANOVA. p<0.001; Figure 18 C represents the intracellular NF-κB content in RAW 264.7 cells under different treatments (n = 3, mean ± SD). Statistical significance was calculated using one-way ANOVA. p<0.001; Figure 18 D is a CLSM map of NLRP3 in RAW 264.7 cells under different treatments (scale bar: 40 μm). Figure 18 E is a pair Figure 18 NLRP3 fluorescence quantitative analysis of D (n = 3, mean ± SD). Statistical significance was calculated by one-way ANOVA. p<0.001.

[0053] Figure 19A shows the CLSM map of Cleaved Caspase-1 in RAW 264.7 cells under different treatments (scale bar: 40 μm). Figure 19 B Figure 19 Quantitative analysis of Cleaved Caspase-1 fluorescence in sample A (n = 3, mean ± SD). Statistical significance was calculated using one-way ANOVA. p<0.001; Figure 19 C is a CLSM map of GSDMD-N in RAW 264.7 cells under different treatments (scale bar: 40 μm). Figure 19 D is the correct answer. Figure 19 Quantitative analysis of GSDMD-N fluorescence in C (n = 3, mean ± SD). Statistical significance was calculated using one-way ANOVA. p<0.001. Detailed Implementation

[0054] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0055] Unless otherwise specified, the experimental methods described in the embodiments are conventional methods; unless otherwise specified, the reagents and materials are commercially available.

[0056] Example 1

[0057] Preparation of a novel PCC@ZnCdS heterojunction nanozyme:

[0058] (1) First, 0.02 mol Co(NO3)2·6H2O and 0.02 mol NaOH were dissolved in 7.5 mL of deionized water to form red and colorless transparent solutions, respectively. Then, at room temperature (25℃), the NaOH solution was added dropwise to the Co(NO3)2 solution with a stirring speed of 800 rpm. After stirring for 30 min, a dark green viscous liquid was obtained. The mixed solution was transferred to a hydrothermal reactor lined with polytetrafluoroethylene and placed in a temperature-controlled oven. The reaction was carried out at 180℃ for 5 h. After the reaction, the product was centrifuged at 8000 rpm for 5 min, the precipitate was collected and washed three times alternately with deionized water and anhydrous ethanol. After each washing, the product was centrifuged under the same conditions. The obtained product was dried in a vacuum drying oven at 80℃ for 12 h. Finally, the dried precursor was calcined in a muffle furnace at 500℃ for 2 h to obtain the target product PCC NPs.

[0059] (2) Dissolve 5 mmol Zn(Ac)2·2H2O and 5 mmol Cd(Ac)2·2H2O in 40 mL of deionized water, sonicate until the solution is clear and transparent, and then rapidly add 0.9391 g thioacetamide (TAA) while stirring vigorously (1000 rpm) for 20 min at 1000 rpm. Dissolve 1.6 g NaOH in 10 mL of deionized water and pour it into the above solution, stirring continuously for 1 h (1000 rpm). After stirring, pour the mixture into a reaction vessel and maintain the reaction at 180℃ for 24 h. Wash the obtained sample three times with water / ethanol (12000 rpm, 5 min) and dry it under vacuum at 60℃ overnight to finally obtain spherical ZnCdS NPs, abbreviated as ZCS NPs.

[0060] (3) 4.17 mmol PCC NPs were dissolved in 20 mL of deionized water and sonicated for 30 min to form product A.

[0061] (4) Dissolve 5 mmol Zn(Ac)2·2H2O and 5 mmol Cd(Ac)2·2H2O in 20 mL of deionized water and sonicate for 30 min to form product B.

[0062] (5) Add product B to product A and stir for 30 min (800 rpm). Under vigorous stirring (1000 rpm), quickly add 0.9391 g TAA, sonicate until completely dissolved, and then stir for 20 min. Add 10 mL of 4 M NaOH solution, stir for 40 min, and then transfer to a reaction vessel to react for 24 h (180℃). Centrifuge and wash the sample to obtain the product PCC@ZnCdS NPs.

[0063] In this process, PCC@ZnCdS NPs with different molar ratios were prepared according to the input molar ratios. The required molar amounts of Zn(Ac)₂·2H₂O and Cd(Ac)₂·2H₂O for preparing ZnCdSNPs were kept constant. The molar amounts of added PCC NPs were varied; that is, the ratio of the molar amount of PCC NPs to the molar amount of Zn(Ac)₂·2H₂O or Cd(Ac)₂·2H₂O was 0.83:5, 1.67:5, 2.5:5, 3.33:5, 4.17:5, 5:5, and 13.33:5, respectively. This corresponds to molar amounts of PCC NPs of 0.83 mmol, 1.67 mmol, 2.5 mmol, 3.33 mmol, 4.17 mmol, 5.00 mmol, and 13.33 mmol, respectively. Seven samples were obtained, namely PZ-0.5, PZ-1.0, PZ-1.5, PZ-2.0, PZ-2.5, PZ-3.0, and PZ-8.0 NPs.

[0064] Example 2

[0065] The material prepared in Example 1 was analyzed by TEM. Figure 1 PCC NPs (PCC) exhibit a cubic structure with a size of 200 nm. ZnCdS NPs (ZnCdS) are nanospheres with a size of 20-30 nm.

[0066] When the two are combined by hydrothermal high temperature and high pressure according to the method of Example 1, the morphology of PZ-2.5 NPs is optimal, and ZnCdS nanospheres are uniformly grown on PCC with a size of 250 nm. To prevent experimental randomness, other synthesis ratios were tried, and their morphological characteristics were observed. In PZ-0.5 NPs, ZnCdS NPs nanospheres were scattered throughout, with very little binding to PCCNPs. The same problem occurred in PZ-1.0 NPs, with excessive and aggregated ZnCdS NPs nanospheres, resulting in poor binding to PCCNPs. In PZ-1.5, the binding between PCC NPs and ZnCdS NPs increased, but many nanospheres were severely aggregated and did not bind to the cubes. In PZ-2.0 NPs, the binding improved, and the agglomeration of nanospheres was reduced, with only partial agglomeration remaining. In PZ-3.0 NPs, the binding of PCC NPs and ZnCdS NPs was clearly visible, but the agglomeration of ZnCdS NPs nanospheres became severe again. The amount of PCC NPs was much greater than that of ZnCdS NPs. NPs were observed to bind with each other, but the binding was poor due to the insufficient amount of microspheres. Therefore, in subsequent experiments, PZ-2.5 NPs were the main component, and a detailed structural analysis of PZ-2.5 NPs was performed.

[0067] The heterojunction structure of PZ-2.5 NPs prepared in Example 1 was investigated using high-magnification transmission electron microscopy. PZ-2.5 NPs is a heterojunction structure of ZnCdS NPs nanospheres grown on PCC NPs, wherein the ZnCdS NPs nanospheres are approximately 20 nm in size, and the PCC NPs are cubic structures with a size of approximately 200 nm. Figure 2 A). The crystal structure of PZ-2.5 NPs was analyzed in the high-magnification transmission electron microscopy image. The (3 1 1) plane of PCC NPs and the (0 0 2) plane of ZnCdS NPs were found in the image, which is consistent with the data of the standard card, proving the successful synthesis of PZ-2.5 NPs heterojunction. Figure 2 B).

[0068] Elemental analysis was performed on the PZ-2.5 NPs heterojunction, revealing the presence of Co, O, Zn, Cd, and S elements. Figure 3 ).

[0069] The tests showed that the potential of PCC NPs was 16.5 mV, and the potential of ZnCdS NPs was -15.03 mV, indicating electrostatic adsorption between the two. With the addition of PCC NPs, the potential of PZ-0.5 NPs became more positive relative to ZnCdS NPs, reaching -9.72 mV. Similarly, the potential of PZ-1.0 NPs was -2.72 mV, PZ-1.5 NPs was -1.34 mV, PZ-2.0 NPs was 1.70 mV, and the potential of PZ-2.5 NPs reached its highest value of 6.74 mV. Subsequently, the potentials of PZ-3.0 NPs and PZ-8.0 NPs decreased to 3.66 mV and -9.68 mV, respectively. This further confirms that both PCC NPs and ZnCdS NPs are bound in materials with different proportions, but the degree of binding varies. Figure 4 A). The hydrodynamic dimensions (DLS) of PZ-2.5 NPs were determined to be stable at 260-280 nm in different solutions (ultrapure water, DMEM, PBS, and DMEM + 10% FBS). Figure 4 B). And in Figure 4 As can be seen in C, 6 ml of 30 μg mL -1 Different solutions of PZ-2.5 NPs remained clear after 7 days, indicating that the material has good dispersibility and stability. The hydrodynamic dimensions are larger than those observed under transmission electron microscopy, which is attributed to the formation of a hydration layer on the surface of the nanomaterial.

[0070] XPS testing results showed characteristic peaks of Zn 2p, Cd 3d, Co 2p, O 1s, S 2p, and C1s in the PZ-2.5 NPs heterojunction. The presence of these peaks indicates the presence of cobalt, oxygen, zinc, cadmium, sulfur, and carbon elements in the sample. The presence of C1s is due to the presence of carbon elements in the copper mesh. Figure 5 A). From the Co 2p spectrum, 781.2 eV (Co 2p 3 / 2 ) and 797.4 eV (Co 2p 1 / 2 The peak at 780 eV belongs to Co(II), and the peak at 780 eV (Co 2p) belongs to Co(II). 3 / 2 ) and 795.5 eV (Co 2p 1 / 2 The peak at position ) belongs to Co(III). Satellite peaks also exist in the figure, which are caused by the multivariate splitting of cobalt. Figure 5 B) indicates that Co is present in the substance. 2+ and Co 3+ .exist Figure 5 In C, the peak at 530 eV is attributed to oxygen in the characteristic Co-O bond. 1022 eV (Zn 2p) 3 / 2), and 1045 eV (Zn 2p 1 / 2 ), the peaks at which belong to Zn(II) ( Figure 5 D). Similarly, it can be known that 405 eV (Cd 3d 5 / 2 ), and 412 eV (Cd d 3 / 2 ), are attributed to Cd(II) ( Figure 5 E). 161.6 eV (S 2p 3 / 2 ), and 162.8 eV (S 2p 1 / 2 ), are attributed to S(II) ( Figure 5 F).

[0071] The electron transport ability of the PZ-2.5 NPs heterojunction was detected by an electrochemical method. As Figure 6 shown in A, the order of the arc radius sizes is: PZ-2.5 NPs < ZnCdS NPs < PCC NPs. After the formation of the heterojunction of PZ-2.5 NPs, the impedance of PZ-2.5 NPs is the smallest, and the electron transport performance is better. Moreover, compared with PCC and ZnCdS, PZ-2.5 NPs show smaller polarization and higher peak current, indicating that PZ-2.5 NPs can favorably promote the redox reaction ( Figure 6 B).

[0072] The ability of the heterojunctions prepared in Example 1 such as PZ-2.5 NPs to scavenge H2O2 in vitro was detected by the titanium sulfate colorimetric method. It can be seen that after the reaction of PZ-2.5 NPs (100 μg mL -1 ) with 10 mM H2O2 for 12 h, the yellow color is the lightest ( Figure 7 A), and the absorbance of the characteristic peak at 415 nm corresponding thereto is also the lowest ( Figure 7 B), and its scavenging rate is up to 45% at most ( Figure 7 C).

[0073] The ability of the different materials prepared in Example 1 to decompose hydrogen peroxide was detected using an oxygen indicator (RDPP). The oxygen generated can quench the fluorescence of RDPP. After calculation, it can be known that after the reaction for 30 min, the fluorescence intensity of RDPP in the group of PZ-2.5 NPs (200 μg mL -1 ) decreased the most, decreasing to 50%, and its oxygen production performance is the best ( Figure 8 ). In this invention, TMB was used as a detection reagent for ·OH. The materials prepared in Example 1 would be oxidized by ·OH to ox-TMB, showing a blue color and having an ultraviolet characteristic absorption peak at 650 nm. Among them, the blue color of PZ-2.5 NPs is the lightest, and the absorbance at 650 nm is the lowest, indicating that PZ-2.5 NPs have the strongest ability to scavenge ·OH ( Figure 9 ).

[0074] The total SOD activity assay kit (WST-8 method) was used to detect superoxide dismutase (SOD) activity, measuring PCC, ZCS, and PZ-2.5 NPs (0, 60, 80, 100, 150 µg mL). -1 SOD enzyme activity. Experimental results showed that ZnCdS NPs could not clear SOD. · O2 - ( Figure 10 B). When 150 μg / mL is reached. -1 At that time, PCC to · O2 - The inhibition rate was 39.94% ( Figure 10 A), PZ-2.5NPs · O2 - The inhibition rate reached 65.97%, demonstrating significant SOD mimicry activity. Figure 10 C).

[0075] To evaluate 40 μg mL -1 The simulated reduced glutathione oxidase (GSH-GPx) activities of different materials (PCC, ZCS, PZ-0.5, PZ-1.0, PZ-1.5, PZ-2.0, PZ-2.5, PZ-3.0, PZ-8.0 NPs) and different concentrations of PCC, ZCS, and PZ-2.5 NPs were investigated using the DTNB method. The results showed that among the different reagents, PZ-2.5 NPs exhibited the lowest absorbance, while GSH-Px showed the strongest activity. Figure 11 ).

[0076] The antioxidant properties of materials were tested using two free radical indicators: DPPH and ABTS. DPPH is a stable free radical with strong absorption near 517 nm, causing the solution to turn purple. Antioxidant substances can pair with the lone pairs of DPPH, gradually weakening its absorption and causing the solution to decolorize. The ability of antioxidants to scavenge DPPH free radicals can be detected by measuring the change in absorbance. 1 mg of DPPH was dissolved in 25 mL of anhydrous ethanol, and 100 µL of DPPH (0.04 mg / mL) was added... -1 ) and 100µL 100 μg mL -1 Different materials (PCC, ZCS, PZ-2.5 NPs) were reacted at room temperature in the dark for 30 min, and the characteristic absorption peak at 517 nm was detected by UV-vis.

[0077] ABTS oxidizes to produce blue-green ABTS. + Free radicals exhibit characteristic absorption around 734 nm. Antioxidants can neutralize ABTS. +The product was reduced to a colorless form, decreasing its absorbance, which was then used to assess its antioxidant activity. First, 14 mmol ABTS solution was incubated overnight with 4.9 mmol potassium persulfate to activate ABTS. ·+ The release of activated ABTS ·+ Dilute with PBS, 100 μg / mL -1 Different materials (PCC, ZCS, PZ-2.5 NPs) and 1 mL ABTS ·+ Incubate at room temperature in the dark for 10 min, then detect the characteristic absorption peak at 734 nm using UV-Vis. Figure 12 A and Figure 13 As shown in Figure A, compared with the control group, PCC, ZCS, and PZ-2.5NPs (100 μg / mL) were added. -1 After [a certain process], the absorbance of all three decreased, indicating that they could scavenge ABTS and DPPH free radicals and exhibit antioxidant properties. The different degrees of decrease indicate differences in the antioxidant properties of the different materials. The absorbance of PZ-2.5 NPs showed the most significant decrease, indicating that its scavenging ability for ABTS and DPPH free radicals was relatively stronger than that of PCC and ZCS. The effect of concentration on antioxidant properties was further investigated, such as... Figure 12 (BD) and Figure 13 (BD) As the material concentration increases, the absorbance gradually decreases, indicating that the material's ability to scavenge ABTS and DPPH free radicals increases with increasing concentration, exhibiting a concentration-dependent effect. This suggests that the material's antioxidant performance can be improved by increasing the concentration within a certain range.

[0078] The effects of PCC, ZCS, and PZ-2.5 NPs on cell viability in different cell lines were detected using the CCK-8 assay. (6 × 10⁶ NPs were then used.) 3 Cells were seeded in 96-well plates and incubated overnight (37°C, 5% CO2) until cell adhesion. Figure 14 As shown in (AE), within the tested concentration range, the three materials maintained high cell viability (>80%) after treatment with five cell types, indicating that the three materials effectively controlled cell viability at different concentrations (0-90 μg / mL). -1PCC, ZCS, and PZ-2.5 NPs exhibited good biocompatibility. Simultaneously, in vitro blood compatibility testing was performed on PZ-2.5 NPs. Blood was drawn from rats and centrifuged for 10 min (2500 rpm). The supernatant was discarded, and PBS was added. The mixture was centrifuged twice more (2500 rpm) until the upper layer was clear. 500 μL of the lower layer of red blood cells was dispersed in 20 mL of PBS to prepare a red blood cell suspension. 500 μL of the red blood cell suspension was added to each centrifuge tube. The control group received an equal amount of PBS and water, while the material groups received 500 μL of different concentrations of the material. The mixtures were incubated at 37°C for 4 h. After incubation, the mixture was centrifuged at 2500 rpm for 5 min, and the samples were collected and photographed. 100 μL of the supernatant was taken and the absorbance at 570 nm was measured using a microplate reader. Figure 14 As shown in F, when the concentration of PZ-2.5 NPs is as high as 400 μg / mL... -1 The hemolysis rate was still below 5%, indicating that it has good blood compatibility.

[0079] The anti-inflammatory and antioxidant capabilities of PZ-2.5 NPs were evaluated. 10 6 RAW 264.7 and Caco-2 cells were seeded in 6-well plates and incubated overnight in a constant temperature incubator (37℃, 5% CO2). The control group was incubated with normal culture medium, while other groups received 1 μg / mL culture medium. -1 Incubate with LPS high-glucose solution for 12 h, discard the supernatant, and then perform PCC NPs (60 μg / mL). -1 ZCS NPs (60 μg mL) -1 ) and PZ-2.5 NPs (60 μg mL) -1 Cells were incubated overnight in the solution. Cells from each group were collected into sterile tubes, centrifuged (2500 rpm, 20 min), and lysed with 200 µL of lysis buffer. The cells were then lysed at 4°C for 30 min, centrifuged again (12000 g, 5 min), and the supernatant was used for analysis. Experimental results are as follows: Figure 15 As shown in Figure A, in RAW 264.7 cells, the intracellular H2O2 content was high after LPS treatment without further material intervention. Treatment with PCC, ZCS, and PZ-2.5 NPs reduced the intracellular H2O2 content, with the PZ-2.5 NPs group exhibiting the lowest H2O2 content. This indicates that LPS stimulation leads to intracellular oxidative stress and ROS production. All three materials possess antioxidant properties, with PZ-2.5 NPs showing the best antioxidant performance. In RAW 264.7 cells, the LPS group, after stimulation without further treatment, showed increasingly severe intracellular inflammation and oxidative stress, resulting in lower cell survival rates. Figure 15 B), and after 60 μg mL-1 Treatment with PCC, ZCS, and PZ-2.5 NPs resulted in high cell viability, indicating that all three materials possess anti-inflammatory and antioxidant activities, alleviating intracellular inflammation and oxidative stress. Furthermore, the concentration of these materials was investigated. Figure 15 C), after LPS stimulation, different concentrations (0-80 μg mL) were added. -1 The anti-inflammatory and antioxidant activities of PZ-2.5 NPs increased with concentration, exhibiting a concentration-dependent effect. Similarly, the same pattern was observed in Caco-2 cells. Figure 15 (DF). The above results indicate that, compared with PCC and ZCS, PZ-2.5 NPs have better anti-inflammatory and antioxidant properties and can alleviate LPS-induced cell damage to the greatest extent.

[0080] The intracellular oxygen production capacity of PZ-2.5 NPs was evaluated. RAW 264.7 cells were seeded in laser confocal dishes, and after they adhered, 1 μg mL of oxygen was added. -1 Replace the old medium with LPS high-glucose medium solution and incubate for 12 h. Discard the supernatant and incubate the cells with RDPP solution (10 μM) for 4 h, then add PCC NPs (60 μg / mL). -1 ZCS NPs (60 μg mL) -1 PZ-2.5 NPs (60 μg mL) -1 After incubating the cells overnight, washing with PBS, and staining with Hoechst 33342 at room temperature for 20 min, the changes in RDPP red fluorescence intensity were observed under CLSM. Figure 16 As shown in Figures A and 16B, the red fluorescence intensity of the Control, LPS, and ZCS groups was similar, while the red fluorescence of the PCC and PZ-2.5 groups was weaker, with the PZ-2.5 group exhibiting the weakest red fluorescence. This indicates that ZCS NPs do not produce oxygen, while PCC and PZ-2.5 NPs do, with PZ-2.5 NPs showing the best oxygen production performance. Simultaneously, the intracellular hypoxia-inducible factor-1α (HIF-1α) content was measured. Figure 16 C) Intracellular oxygen production inhibits HIF-1α secretion, consistent with the previous trend. RAW 264.7 cells treated with PZ-2.5 NPs showed the lowest intracellular HIF-1α content and the best oxygen production performance, which can alleviate the hypoxic microenvironment of colitis.

[0081] The effect of PZ-2.5 NPs on macrophage phenotypic transformation was quantitatively evaluated. RAW 264.7 cells were seeded in laser confocal microscopy dishes. After cell adhesion, the culture medium was replaced with a medium containing 1 μg / mL of PZ-2.5 NPs. -1 LPS was incubated in high-glucose medium for 12 h. Then, 60 μg mL of LPS was added to each culture dish.-1 PCC NPs, ZCS NPs, and PZ-2.5 NPs were added and incubated with cells overnight. The supernatant was discarded, and the cells were gently washed three times with PBS to remove unbound nanoparticles and culture medium residue. Cells were then fixed with 4% paraformaldehyde (PFA) solution for 15 min, followed by washing with PBS to remove the fixative. Cells were then blocked with 3% bovine serum albumin (BSA) for 30 min to reduce non-specific binding. CD86 (Proteintech, 13395-1-AP) and CD206 (Proteintech, 18704-1-AP) antibodies were added, and the cells were co-cultured overnight at 4°C. After incubation, the cells were washed multiple times with PBS to remove unbound primary antibodies. The samples were then incubated with goat anti-rabbit IgG-RBITC (Solarbio, SR134) antibody for 1 h, followed by washing three times with PBS to remove unbound secondary antibodies. Cell nuclei were then stained with Hoechst 33342, followed by multiple washes with PBS to remove unbound dye. Finally, the samples were observed and imaged under CLSM. CD86 is a characteristic protein of M1 macrophages, and CD206 is a characteristic protein of M2 macrophages; both CD86 and CD206 were labeled with red fluorescent dye. LPS is often used as a stimulant to induce macrophage polarization towards the M1 type, such as... Figure 17 As shown in A and 17B, after LPS treatment, the CD86 fluorescence in the LPS group was significantly stronger than that in the control group. The PCC and ZCS groups also showed some increase, but not as significantly as the LPS group. The PZ-2.5 group showed the weakest fluorescence, indicating that it had the weakest effect on inducing macrophages to the M1 phenotype. Figure 17 As shown in C and 17D, the CD206 fluorescence intensity in the LPS group was lower than that in the control group, consistent with the characteristic that the expression of M2-type characteristic proteins is inhibited during M1-type macrophage polarization. The increased CD206 fluorescence intensity in PCC and ZCS indicates that these two treatments may promote macrophage polarization towards the M2 phenotype, but the CD206 fluorescence intensity in the PZ-2.5 group was significantly higher than that in the control group, indicating that it had the strongest promoting effect on macrophage polarization towards M2. Consistent with the above experimental results, PZ-2.5 NPs inhibited the secretion of inflammatory cytokines (IL-1β), promoted macrophage transformation to the M2 phenotype, promoted the secretion of anti-inflammatory cytokines (IL-10), cleared the existing inflammatory microenvironment, and also promoted a positive anti-inflammatory cycle, thus exerting the immunomodulatory role of macrophages.

[0082] The ability of PZ-2.5 NPs to inhibit NLRP3 inflammasome activation was quantitatively evaluated. ROS is an upstream factor in NLRP3 inflammasome activation, and the NLRP3 inflammasome plays an important role in colitis. H2S can exert anti-inflammatory effects, and its synthesis increases under pro-inflammatory conditions, inhibiting nuclear factor-κB (NF-κB) pathway activation and thus inhibiting NLRP3 inflammasome activation. The expression of GSDMD-N protein in RAW 264.7 cells was measured. Cells were seeded in laser confocal microscopy dishes, and when they covered the bottom of the dish, the old culture medium was discarded, and 1 μg mL of medium was added. -1 Cells were co-incubated with high-glucose medium containing LPS for 12 h. Subsequently, the medium was replaced with different solutions (PCC NPs, ZCS NPs, and PZ-2.5 NPs) and incubated overnight. Cells were fixed with 4% PFA, washed with PBS, and then blocked with 3% BSA. After washing three times, the samples were incubated overnight with GSDMD-N primary antibody and then with secondary antibody at room temperature for 1 h. After washing with PBS, cell nuclei were stained with Hoechst 33342, and changes in immunofluorescence intensity were observed under CLSM. Following the above procedures, the expression of NLRP3 and Cleaved-Caspase-1 in cells after different treatment conditions was detected, and immunofluorescence was observed under CLSM. The experimental results are as follows: Figure 18 As shown in Figure A, LPS stimulation induced cellular inflammation, decreased ATP synthesis, and downregulated PCC, ZCS, and PZ-2.5 synthesis, attributed to mitochondrial membrane depolarization and activation of mitophagy. Intracellular H2S levels were also measured. Figure 18 B) After LPS stimulation, the content of H2S increased compared to the control group, and all groups, including PCC, ZCS, and PZ-2.5, showed an increase, with the ZCS group showing the highest content. This is attributed to the increased H2S synthesis under inflammatory stimulation, and the fact that ZnCdS NPs provided the S source. After entering the cell, the acidic environment of the lysosome promoted the release of H2S. Figure 18 As shown in Figure C, after LPS stimulation, intracellular NF-κB levels increased, while PCC, ZCS, and PZ-2.5 NPs were downregulated, with the PZ-2.5 group showing the lowest levels. NF-κB is a key factor in inflammatory signaling pathways and promotes NLRP3 inflammasome activation. Treatment with PCC, ZCS, and PZ-2.5 NPs inhibited its activation and reduced the inflammatory response. Figure 18 D and Figure 18As shown in Figure E, LPS treatment significantly increased NLRP3 expression, while PCC, ZCS, and PZ-2.5 NPs treatments downregulated it, with the PZ-2.5 group showing the lowest expression. NLRP3 is an important component of the inflammasome, indicating that all three treatments can inhibit inflammasome activation, with PZ-2.5 NPs showing the strongest inhibitory effect. Cleaved Caspase-1 expression was detected by immunofluorescence and quantification using mean fluorescence intensity. Figure 19 As shown in A and 19B, LPS treatment significantly increased the expression of Cleaved Caspase-1. The expression in the PCC, ZCS, and PZ-2.5 treatment groups was lower than that in the LPS group, with the lowest expression in the PZ-2.5 group. Cleaved Caspase-1 is a downstream product of inflammasome activation, indicating that PZ-2.5 treatment inhibited its activation. Figure 19 C and 19D assays revealed the same pattern in GSDMD-N expression. LPS treatment significantly increased GSDMD-N expression, with lower expression in the PCC, ZCS, and PZ-2.5 treatment groups compared to the LPS group, and the lowest expression in the PZ-2.5 group. GSDMD-N is associated with pyroptosis, indicating that PZ-2.5 NPs treatment can inhibit pyroptosis. These results collectively suggest that LPS can activate inflammation-related pathways, while PCC, ZCS, and PZ-2.5 can inhibit inflammation to varying degrees. PZ-2.5 NPs showed the best inhibitory effect, exerting its anti-inflammatory effect by activating mitophagy, releasing H2S, inhibiting NF-κB pathway activation, thereby suppressing NLRP3 inflammasome activation and pyroptosis.

Claims

1. A heterojunction nanozyme, characterized in that, Cubic Co3O4 (PCC NPs) was first synthesized via a hydrothermal method. By changing the molar ratio of PCC NPs with zinc and cadmium sources, a series of heterojunction nanozymes were synthesized under high temperature and high pressure conditions.

2. The heterojunction nanozyme according to claim 1, characterized in that, The heterojunction nanozyme has a cubic structure with nanospheres uniformly growing around the cube, with a size of approximately 230-270 nm.

3. A method for preparing the heterojunction nanozyme according to claim 1, characterized in that, Includes the following steps: (1) Dissolve Co(NO3)2·6H2O and NaOH in deionized water respectively. Add NaOH solution dropwise to Co(NO3)2 solution while stirring. After continuous stirring, carry out hydrothermal reaction of the mixed solution to obtain the precursor. Calcine the dried precursor to obtain the target product PCC NPs. (2) Dissolve Zn(Ac)2·2H2O and Cd(Ac)2·2H2O in deionized water, sonicate, add thioacetamide (TAA), and stir continuously. Dissolve NaOH in deionized water and pour it into the above solution. Stir continuously. After stirring, wash and dry the sample obtained by high temperature reaction of the mixture to finally obtain ZnCdS NPs. (3) Dissolve PCC NPs in deionized water and sonicate to obtain product A; dissolve Zn(Ac)2·2H2O and Cd(Ac)2·2H2O in deionized water and sonicate to obtain product B; add solution B to solution A, add TAA while stirring, and sonicate to obtain product C; (4) Add NaOH solution to product C, stir thoroughly, and react at high temperature until the product PCC@ZnCdS NPs is obtained.

4. The method for preparing heterojunction nanozymes according to claim 1, characterized in that, In step (1), the molar ratio of NaOH to Co(NO3)2·6H2O is 1~6:1~1.

5. The method for preparing heterojunction nanozymes according to claim 1, characterized in that, In step (2), the molar ratio of Zn(Ac)2·2H2O and Cd(Ac)2·2H2O is 1~2:1~1; the molar ratio of Cd(Ac)2·2H2O and TAA in step (2) is 1~5:1~2.

6. The method for preparing heterojunction nanozymes according to claim 1, characterized in that, In step (3), the molar ratio of PCC NPs to TAA is 1~5:1~2.

7. The method for preparing heterojunction nanozymes according to claim 1, characterized in that, In step (4), the temperature of the hydrothermal reaction is 120℃~180℃ and the time is 10 h~48 h.

8. The method for preparing heterojunction nanozymes according to claim 1, characterized in that, In step (4), PCC@ZnCdS NPs with different proportions were prepared according to the molar ratio of input. While keeping the molar amounts of Zn(Ac)2·2H2O and Cd(Ac)2·2H2O constant, the molar amount of added PCC NPs was changed to obtain seven samples: PZ-0.5, PZ-1.0, PZ-1.5, PZ-2.0, PZ-2.5, PZ-3.0, and PZ-8.0 NPs.

9. The use of the heterojunction nanozyme of claim 1 in the preparation of anti-inflammatory reagents or drugs.

10. The application according to claim 9, characterized in that, The anti-inflammatory treatment includes treatment for ulcerative colitis or atherosclerosis.

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