SOD@ ZIF-8 / Mn3O4 composite nanomaterial, preparation method thereof and application thereof in paracetamol-induced acute liver injury

Abstract

This invention discloses an SOD@ZIF-8 / Mn3O4 composite nanomaterial, its preparation method, and its application in acetaminophen-induced acute liver injury, belonging to the field of biomedical technology. The SOD@ZIF-8 / Mn3O4 composite nanomaterial uses ZIF-8 as a nanocarrier, with SOD embedded inside ZIF-8 and Mn3O4 nanoenzymes anchored on the surface of ZIF-8, forming an SOD@ZIF-8 / Mn3O4 complex. This invention embeds natural superoxide dismutase into a ZIF-8 metal-organic framework through biomimetic mineralization, and then anchors citric acid-functionalized Mn3O4 nanoparticles to its surface to obtain the composite nanomaterial. The material exhibits multi-enzyme-like activity, achieving responsive dissociation and SOD release under cascade conditions, activating the Keap1 / Nrf2 / HO-1 antioxidant pathway and inhibiting the NF-κB inflammatory pathway to exert a hepatoprotective effect.

Description

Technical Field

[0001] This invention relates to the field of biomedical technology, and in particular to an SOD@ZIF-8 / Mn3O4 composite nanomaterial, its preparation method, and its application in acetaminophen-induced acute liver injury. Background Technology

[0002] Acute liver injury (ALI) is a rapidly progressing and severe liver disease, typically characterized by extensive hepatocellular necrosis and impaired liver function. Clinically, ALI is often caused by drug overdose, with acetaminophen (APAP)-related injuries accounting for approximately 60%–70%. Globally, there are over 100,000 APAP poisoning incidents annually, with an in-hospital mortality rate of up to 30%, indicating its high lethality and significant socioeconomic burden.

[0003] Currently, treatment options for ALI remain limited, primarily including antioxidant therapy or liver transplantation. While N-acetylcysteine ​​(NAC) is a major clinical antidote, its effectiveness is limited by a narrow therapeutic window, its limited ability to regulate ferroptosis pathways during the progression of injury, and the practical problems of donor shortages and high costs associated with liver transplantation. Therefore, there is an urgent need to develop new intervention strategies that are more efficient and can precisely regulate oxidative stress and inflammatory responses.

[0004] The pathological microenvironment of ALI is typically accompanied by rapid and excessive accumulation of reactive oxygen species (ROS) and enhanced lipid peroxidation; oxidative stress is considered a key driver of disease progression. This is especially true under ALI conditions, where superoxide anions (O2·) are particularly abundant. - ) and hydrogen peroxide (H2O2) can accumulate rapidly in cells, inducing stronger oxidative damage and exacerbating tissue dysfunction.

[0005] Studies also suggest that excessive APAP can lead to the depletion of intracellular glutathione (GSH), further triggering lipid peroxidation and increased levels of peroxidation products such as malondialdehyde (MDA); simultaneously, it inhibits GPX4 activity, ultimately triggering ferroptosis and amplifying hepatocellular damage. In addition, excessive APAP can activate the liver's innate immune response, stimulating resident hepatic macrophages (Kupffer cells) to release inflammatory mediators such as IL-1β, IL-6, and CXCL1, accompanied by upregulation of molecules such as G-CSF and VCAM-1, promoting neutrophil recruitment and amplifying inflammation, thereby further exacerbating liver damage. Therefore, effective treatment for ALI usually requires a multi-target synergistic approach, encompassing broad-spectrum ROS clearance, inhibition of lipid peroxidation, blocking ferroptosis, and reduction of inflammatory storms.

[0006] Superoxide dismutase (SOD) is a key antioxidant enzyme in the body that catalyzes the oxidation of O2·2O3. - Superoxide dismutation (SOD) to H2O2 and O2 is a core defense line for cells against superoxide-related oxidative damage, and enhancing SOD activity is considered a potential strategy to alleviate oxidative stress in ALI (Alternative Inflammatory Disease). However, the in vivo application of natural SOD still faces limitations such as rapid clearance, insufficient stability, and lack of targeted delivery capabilities, hindering its clinical translation. There is an urgent need to improve its stability, accumulation capacity, and bioavailability through delivery systems. In recent years, nanomaterials with enzyme-like catalytic activity have provided a new material basis for antioxidant therapy. Among them, manganese-based oxide nanoparticles (such as Mn3O4) can exhibit multi-enzyme mimicry activities such as SOD-like, catalase (CAT)-like, and glutathione peroxidase (GPX)-like activities, capable of clearing various ROS and reported to have the potential to inhibit ferroptosis. Simultaneously, manganese-based nanoparticles have a certain tendency to accumulate in the liver, and can achieve tissue uptake through Kupffer cells and the hepatic vascular system, thus potentially forming a high effective concentration locally in liver tissue and exerting a sustained antioxidant effect. However, relying solely on a single natural enzyme or a single nanozyme often fails to simultaneously cover O2· - The continuous conversion requirements of various ROS such as H2O2 also make it difficult to simultaneously address the systemic regulation of downstream pathways such as inflammation and ferroptosis.

[0007] Metal-organic frameworks (MOFs), due to their tunable pore structure, high specific surface area, and structural diversity, have been used in recent years for enzyme immobilization and delivery, improving enzyme stability and reducing degradation. Zeolitic imidazolate framework 8 (ZIF-8), formed by the self-assembly of zinc ions and 2-methylimidazolium ligands, exhibits good biocompatibility and mild preparation conditions. It can encapsulate biomolecules such as proteins / enzymes through biomimetic mineralization while maintaining their activity and reducing premature leakage. More importantly, ZIF-8 is degradable under slightly acidic conditions, enabling responsive release of the encapsulated material within the microenvironment of inflamed tissues (such as damaged liver tissue), providing a material advantage for constructing multi-enzyme cascade catalytic platforms. However, the application of ZIF-8 cascade systems for liver injury treatment still lacks systematic research and translational validation.

[0008] Therefore, it is necessary to develop an antioxidant cascade platform that integrates natural enzymes and nanozymes, utilizing carrier materials to enhance the stability and targeted delivery capabilities of natural enzymes, and achieving continuous clearance of multiple ROS through multi-enzyme cascade simulation. At the same time, it can synergistically regulate key pathological processes such as inflammation and ferroptosis to meet the clinical needs of drug-induced liver injury (especially APAP-related ALI) in terms of therapeutic window, pathway coverage and comprehensive benefits. Summary of the Invention

[0009] The purpose of this invention is to provide an SOD@ZIF-8 / Mn3O4 composite nanomaterial, its preparation method, and its application in acetaminophen-induced acute liver injury, thereby addressing the problems existing in the prior art. To solve the problems of insufficient in vivo stability and limited targeted enrichment capacity of natural antioxidant enzymes (such as SOD) in the prior art, and the difficulty of single antioxidant strategies simultaneously covering multiple key aspects such as ROS scavenging, inflammatory pathway inhibition, and ferroptosis blocking, this invention aims to provide a novel and efficient multi-target synergistic intervention strategy for drug-induced liver injury. This involves constructing an antioxidant cascade platform that synergistically integrates natural enzymes and nanozymes, broadly scavenging reactive oxygen species and synergistically regulating downstream oxidative stress, inflammation, and ferroptosis-related pathways, thereby achieving comprehensive protection against liver injury.

[0010] To achieve the above objectives, the present invention provides the following solution: One of the technical solutions of the present invention is an SOD@ZIF-8 / Mn3O4 composite nanomaterial, wherein the SOD@ZIF-8 / Mn3O4 composite nanomaterial uses ZIF-8 as a nanocarrier, with SOD embedded inside ZIF-8 and Mn3O4 nanoenzymes anchored on the surface of ZIF-8 to form an SOD@ZIF-8 / Mn3O4 complex.

[0011] The second technical solution of the present invention, the preparation method of the SOD@ZIF-8 / Mn3O4 composite nanomaterial, includes the following steps: (1) Synthesis of Mn3O4 nanoparticles; (2) The SOD packet is embedded in ZIF-8 to obtain SOD@ZIF-8; (3) Mix the Mn3O4 nanoparticles obtained in step (1) with the SOD@ZIF-8 obtained in step (2) to form SOD@ZIF-8 / Mn3O4 composite nanomaterials by self-assembly.

[0012] The third technical solution of the present invention is the application of the SOD@ZIF-8 / Mn3O4 composite nanomaterial in the preparation of a drug for treating acetaminophen-induced acute liver injury.

[0013] The fourth technical solution of the present invention is a drug for treating acetaminophen-induced acute liver injury, comprising the SOD@ZIF-8 / Mn3O4 composite nanomaterial.

[0014] Based on the above technical solution, the present invention has the following technical effects: (1) Broad-spectrum ROS scavenging and cascade catalysis: Compared with the control system, the platform showed stronger free radical and ROS scavenging capabilities in ABTS / DPPH evaluation, and had quantifiable SOD / CAT / GPX multi-enzyme-like activities.

[0015] (2) Good cell delivery efficiency: It has low toxicity in AML-12 cells, can be efficiently endocytosed and escaped from lysosomes, which is conducive to cytoplasmic delivery and antioxidant effects.

[0016] (3) Clear in vivo efficacy and preferential accumulation in the liver: In the APAP-induced acute liver injury model, it significantly reduced ALT / AST, improved liver tissue necrosis, and downregulated multiple inflammatory mediators; after intravenous administration, it preferentially accumulated in the liver, reaching its peak at about 12 h.

[0017] (4) Good biocompatibility: It has low toxicity in vivo, low hemolysis rate, and does not affect liver and kidney function after injection. Attached Figure Description

[0018] Figure 1 This diagram illustrates the synthesis of the synergistic integration of natural enzymes and nanozymes into an antioxidant cascade platform (SOD@ZIF-8 / Mn3O4) according to the present invention. In the diagram, A represents the synthesis of Mn3O4 nanoparticles, and B represents the synthesis of the SOD@ZIF-8 / Mn3O4 complex.

[0019] Figure 2 Characterization diagrams of SOD@ZIF-8 / Mn3O4 are shown. Among them, (A) TEM image of Mn3O4 nanoparticles; (B) particle size distribution of Mn3O4; (C) SEM image of SOD@ZIF-8 / Mn3O4 composite; (D) STEM image and elemental distribution (Zn, N, O, Mn, C) mapping.

[0020] Figure 3 Characterization diagrams of the physicochemical properties and catalytic mechanism of SOD@ZIF-8 / Mn3O4. (A) Hydrated particle size distribution of the aqueous dispersion system; (B) Zeta potential; (C) XRD patterns of ZIF-8, Mn3O4, and the complex; (D) FTIR spectra verifying successful integration of SOD and Mn3O4; (E) N2 adsorption-desorption isotherms; (F) XPS total spectrum; (GI) Gibbs free energy changes along the SOD / CAT / GPX path calculated by DFT.

[0021] Figure 4 The image shows the in vitro broad-spectrum antioxidant properties of SOD@ZIF-8 / Mn3O4. (A, B) shows the free radical scavenging experiments of ABTS and (C, D) DPPH (color / absorbance changes of control and different concentration treatments).

[0022] Figure 5 To assess the uptake and intracellular delivery of SOD@ZIF-8 / Mn3O4 in AML-12 cells, (A) flow cytometry analysis of cell uptake at different time points; (B) confocal observation of lysosomal escape of FITC-labeled nanoplatforms within 12 h (Lysotracker red-labeled lysosomes).

[0023] Figure 6 DCFH-DA was used to detect intracellular ROS. (A) Fluorescence image; (B) Quantitative analysis.

[0024] Figure 7 In the study, (A) GSH content; (B) MDA content; and (C) apoptosis analysis by flow cytometry.

[0025] Figure 8 The in vivo therapeutic effect of SOD@ZIF-8 / Mn3O4 in a mouse model of APAP-induced acute liver injury: H&E staining and immunofluorescence staining of liver tissue.

[0026] Figure 9 This image shows the liver-targeted enrichment of SOD@ZIF-8 / Mn3O4 in a mouse model of APAP-induced acute liver injury. (A) In vivo fluorescence imaging; (B) Quantification of liver enrichment over time.

[0027] Figure 10 This graph shows the changes in inflammatory factors in vivo caused by SOD@ZIF-8 / Mn3O4. In the graph, A represents IL-1β, B represents IL-6, C represents CXCL1, D represents G-CSF, and E represents VCAM-1.

[0028] Figure 11 To assess the biocompatibility of SOD@ZIF-8 / Mn3O4 in vivo, the following factors were considered: (A) changes in body weight; (B) hemolysis test; (C) H&E staining of major organs; and (D) liver and kidney function. Detailed Implementation

[0029] Unless otherwise specified, the technical solutions described in this invention are all conventional solutions in the field, and the reagents or raw materials used are all purchased from commercial channels or are publicly available unless otherwise specified.

[0030] This invention provides an SOD@ZIF-8 / Mn3O4 composite nanomaterial, wherein ZIF-8 is used as a nanocarrier, SOD is embedded inside ZIF-8, and Mn3O4 nanoenzymes are anchored on the surface of ZIF-8 to form an SOD@ZIF-8 / Mn3O4 complex.

[0031] In some specific implementations, the Mn3O4 nanozyme is surface-functionalized with citric acid and then anchored to the ZIF-8 surface via self-assembly.

[0032] The ZIF-8 is formed by the self-assembly of zinc ions and 2-methylimidazolium ligands. The SOD@ZIF-8 / Mn3O4 composite nanomaterial exhibits multi-enzyme-like activities, including SOD-like, CAT-like, and GPX-like activities, used to scavenge reactive oxygen species and alleviate oxidative stress. In the ABTS free radical scavenging experiment, the SOD@ZIF-8 / Mn3O4 composite nanomaterial achieved a scavenging rate exceeding 80% in the concentration range of 100–400 μg / mL. The SOD-like activity of the SOD@ZIF-8 / Mn3O4 composite nanomaterial was evaluated using the WST-1 method, showing an activity of approximately 65% ​​at 30 μg / mL; the CAT-like activity exceeded 60% for hydrogen peroxide decomposition at 100 μg / mL; and the GPX-like activity reached approximately 80% at 100 μg / mL. The SOD@ZIF-8 / Mn3O4 composite nanomaterial remains stable at pH 7.4 and undergoes controlled progressive dissociation at pH 5.5, thereby achieving pH-responsive release of SOD.

[0033] This invention also provides a method for preparing the SOD@ZIF-8 / Mn3O4 composite nanomaterial, comprising the following steps: (1) Synthesis of Mn3O4 nanoparticles; (2) The SOD packet is embedded in ZIF-8 to obtain SOD@ZIF-8; (3) Mix the Mn3O4 nanoparticles obtained in step (1) with the SOD@ZIF-8 obtained in step (2) to form SOD@ZIF-8 / Mn3O4 composite nanomaterials by self-assembly.

[0034] In some specific implementations, in step (1), the method for synthesizing the Mn3O4 nanoparticles is as follows: Mn(OAc)2·4H2O is dissolved in DMF and reacted in a high-pressure reactor at 120-140℃ for 6-10 h. After centrifugation, washing, and freeze-drying, Mn3O4 nanoparticles are obtained.

[0035] In some specific implementations, in step (2), the preparation method of SOD@ZIF-8 is as follows: SOD is dissolved in a methanol solution containing 2-methylimidazole, a methanol solution containing Zn(NO3)2·6H2O is added, the mixture is stirred at room temperature, the precipitate is collected by centrifugation, and SOD@ZIF-8 is obtained after washing.

[0036] In some specific implementations, in step (3), the Mn3O4 nanoparticles are first surface-functionalized with citric acid solution before being mixed with SOD@ZIF-8.

[0037] This invention also provides the application of the SOD@ZIF-8 / Mn3O4 composite nanomaterial in the preparation of a drug for treating acetaminophen-induced acute liver injury.

[0038] In some specific implementations, the SOD@ZIF-8 / Mn3O4 composite nanomaterials achieve multi-target synergistic protection against liver injury by scavenging reactive oxygen species, inhibiting lipid peroxidation, blocking ferroptosis, and / or inhibiting the expression of inflammatory factors.

[0039] This invention also provides a drug for treating acetaminophen-induced acute liver injury, comprising the SOD@ZIF-8 / Mn3O4 composite nanomaterial.

[0040] In some specific implementation schemes, pharmaceutically acceptable carriers are also included.

[0041] The SOD@ZIF-8 / Mn3O4 composite nanomaterial exerts a hepatoprotective effect by simultaneously activating the Keap1 / Nrf2 / HO-1 antioxidant pathway and inhibiting the NF-κB inflammatory pathway. Furthermore, the SOD@ZIF-8 / Mn3O4 composite nanomaterial inhibits APAP-triggered ferroptosis-related damage by restoring GPX4 expression.

[0042] The SOD@ZIF-8 / Mn3O4 composite nanomaterial is obtained by co-integrating a natural enzyme (SOD) with a multifunctional nanoenzyme (Mn3O4) into a ZIF-8 nanocarrier, and is used to comprehensively alleviate oxidative stress and related inflammatory responses. The ZIF-8 nanocarrier is characterized by degradation under slightly acidic conditions, enabling responsive release of the encapsulated components within the microenvironment of inflamed / damaged liver tissue.

[0043] This invention encapsulates natural superoxide dismutase (SOD) within a ZIF-8 metal-organic framework using a biomimetic mineralization process, and then anchors citric acid-functionalized Mn3O4 nanoparticles onto its surface to obtain a composite nanomaterial. This material exhibits multi-enzyme-like activity and can achieve responsive dissociation and SOD release through a cascade environment. The material exerts a hepatoprotective effect by activating the Keap1 / Nrf2 / HO-1 antioxidant pathway and inhibiting the NF-κB inflammatory pathway, while simultaneously inhibiting APAP-related ferroptosis by restoring the expression of key proteins such as GPX4. Therefore, it can be used to prepare drugs or formulations for the prevention or treatment of acetaminophen-induced acute liver injury.

[0044] The antioxidant cascade platform provided by this invention uses a ZIF-8 metal-organic framework as a nanocarrier, embedding natural superoxide dismutase (SOD) within ZIF-8 to enhance its stability and reduce protease degradation. Simultaneously, a multifunctional Mn3O4 nanozyme is anchored on its surface to endow the system with multi-enzyme-like activities such as SOD / CAT / GPX, forming a synergistic catalytic cascade capable of scavenging various free radicals or ROS, including ABTS and DPPH, and achieving responsive release in the slightly acidic environment of inflamed tissues. Verification has shown that the nanoplatform constructed in this invention exhibits good biocompatibility; the nanoplatform can be efficiently internalized by cells and escapes via lysosomes, which is beneficial for exerting antioxidant and cascade catalytic effects in the cytoplasmic environment.

[0045] At the mechanistic level, the nanoplatform of this invention can activate the APAP-induced NF-κB pathway, thereby reducing the expression of pro-inflammatory factors such as IL-1β, IL-6, and TNF-α. Simultaneously, the platform can protect hepatocytes through a dual action of anti-oxidation and anti-lipid peroxidation, and can be used for the prevention and treatment of oxidative stress-related liver injury (including APAP hepatotoxicity). In an in vivo APAP-induced acute liver injury model (intraperitoneal injection of APAP 300 mg / kg), the platform significantly reduced serum ALT / AST levels, improved liver bright-field morphology, and alleviated histological necrosis; it also reduced the levels of inflammation-related mediators (IL-1β, IL-6, CXCL1, G-CSF, VCAM-1). Furthermore, after intravenous administration, the platform showed preferential enrichment in the liver: in vivo fluorescence signals increased in the liver over time and peaked at approximately 12 h; ICP-MS also showed that Mn was mainly enriched in the liver at 12 h.

[0046] Example 1 Preparation of SOD@ZIF-8 / Mn3O4 (1) Synthesis of Mn3O4 nanoparticles: 0.7 g of Mn(OAc)2·4H2O was dissolved in 30 mL of N,N-dimethylformamide (DMF) and transferred to a 50 mL polytetrafluoroethylene-lined high-pressure reactor. The reaction was carried out at 130 °C for 8 h. After natural cooling, the product was repeatedly washed by centrifugation with ethanol and deionized water and then freeze-dried for later use.

[0047] (2) Synthesis of SOD@ZIF-8: 5 mg of superoxide dismutase (SOD) was dissolved in 10 mL of methanol solution containing 2-methylimidazole (2-MIM, 9.85 g). After complete dissolution, 5 mL of methanol solution containing Zn(NO3)2·6H2O (1.17 g) was added dropwise, and the mixture was stirred at room temperature for 1 h. The reaction solution was centrifuged (8000 rpm, 10 min), the precipitate was collected, washed twice with methanol, and redispersed in water for later use.

[0048] (3) Synthesis of SOD@ZIF-8 / Mn3O4: Mn3O4 nanoparticles (20 mg / mL) were dispersed in 0.5 M citric acid solution (pH 7.0) and stirred for 12 h for surface functionalization. Free citric acid was removed by dialysis. The functionalized Mn3O4 and SOD@ZIF-8 solution were mixed at a 1:1 molar ratio, stirred at room temperature for 24 h, and centrifuged and washed to obtain the SOD@ZIF-8 / Mn3O4 complex.

[0049] Example 2 Characterization of nanozymes The morphology of Mn3O4 and SOD@ZIF-8 / Mn3O4 was observed by transmission electron microscopy (TEM); hydration particle size and zeta potential were determined by dynamic light scattering (DLS); crystal structure was analyzed by X-ray diffraction (XRD); composition was verified by Fourier transform infrared spectroscopy (FTIR); elemental valence states were analyzed by X-ray photoelectron spectroscopy (XPS); specific surface area and pore size were determined by nitrogen adsorption-desorption; and energy barriers of catalytic pathways were calculated by density functional theory (DFT).

[0050] The results are as follows Figure 2-3 As shown, this indicates that a uniformly sized and structurally complete SOD@ZIF-8 / Mn3O4 nanozyme with multi-enzyme activity was successfully synthesized.

[0051] Example 3 In vitro antioxidant activity evaluation The broad-spectrum antioxidant capacity of nanozymes was evaluated using ABTS and DPPH free radical scavenging assays. The results showed that SOD@ZIF-8 / Mn3O4 exhibited concentration-dependent free radical scavenging activity, and its effect was superior to ZIF-8 / Mn3O4 (…). Figure 4 ).

[0052] EPR detection of ·OH and O2 - The results showed that SOD@ZIF-8 / Mn3O4 could effectively remove both types of ROS.

[0053] SOD-like, CAT-like, and GPX-like activities were determined using the WST-1 method, ammonium molybdate method, and DTNB method, respectively. The results showed that the nanozyme exhibited concentration-dependent multi-enzyme activity.

[0054] Example 4 Cellular uptake and lysosomal escape The FITC fluorescent probe and SOD were conjugated by incubation in PBS for 24 h. The molar ratio of SOD to fluorescent probe was 1:3. The solution was then dialyzed to remove impurities, and then SOD@ZIF-8 / Mn3O was synthesized according to the method in Example 1. 4。

[0055] FITC-labeled SOD@ZIF-8 / Mn3O4 was co-incubated with AML-12 cells for different time periods. Flow cytometry showed that cell uptake increased over time. Figure 5 (A). Confocal microscopy showed that green fluorescence (FITC) and red fluorescence (Lysotracker) were co-localized at 2-4 h, and completely separated at 12 h, indicating that the nanozyme successfully escaped the lysosome. Figure 5 (B)

[0056] Example 5 Intracellular oxidative stress level detection An injury model was established by treating AML-12 cells with APAP (1.2 mg / mL) for 24 h. DCFH-DA staining showed that the ROS fluorescence intensity was significantly increased in the APAP group, while the ROS level in the SOD@ZIF-8 / Mn3O4 pretreatment group decreased by about 6-fold. Figure 6 ).

[0057] GSH and MDA detection showed that SOD@ZIF-8 / Mn3O4 could restore GSH content and reduce MDA level. Figure 7 (AB). Flow cytometry apoptosis detection showed that the apoptosis rate in the APAP group was 54.50%, while it decreased to 11.89% in the SOD@ZIF-8 / Mn3O4 group. Figure 7 (C)

[0058] Example 6 Evaluation of treatment effects in animal models Male C57BL / 6 mice were randomly divided into 5 groups: Control, APAP, SOD@ZIF-8, ZIF-8 / Mn3O4, and SOD@ZIF-8 / Mn3O4. An ALI model was established by intraperitoneal injection of APAP (300 mg / kg). After 24 hours, serum ALT / AST levels significantly increased, and obvious liver lesions were visible. This confirmed the successful establishment of the ALI model. After confirming the successful establishment of the model groups, serum ALT / AST levels were measured in each group, and liver tissue was collected for H&E staining and immunofluorescence analysis.

[0059] The results showed that ALT / AST was significantly elevated in the APAP group, with extensive necrosis of liver tissue; ALT / AST was significantly decreased in the SOD@ZIF-8 / Mn3O4 group, with improved liver tissue pathology. Figure 8 Immunofluorescence showed that SOD@ZIF-8 / Mn3O 44 Increased Nrf2 nuclear translocation and decreased p-p65 expression in the group indicate that antioxidant and anti-inflammatory pathways are activated. Figure 8 ).

[0060] Example 7 Liver targeting and biosafety The distribution of Cy5.5-labeled SOD@ZIF-8 / Mn3O4 in mice was observed using in vivo fluorescence imaging. Results showed that the liver showed the strongest enrichment 12 h post-injection. Figure 9 ICP-MS analysis showed that Mn accumulation was highest in the liver.

[0061] Serum inflammatory factor detection showed that SOD@ZIF-8 / Mn3O4 significantly reduced the levels of IL-1β, IL-6, CXCL1, G-CSF, and VCAM-1. Figure 10 ).

[0062] Biosafety assessment: No significant change in body weight, hemolysis rate <5%, no obvious damage observed in H&E staining of major organs, and normal liver and kidney function indicators. Figure 11 ).

[0063] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A SOD@ZIF-8 / Mn304 composite nanomaterial, characterized in that, The SOD@ZIF-8 / Mn3O4 composite nanomaterial uses ZIF-8 as a nanocarrier, with SOD embedded inside ZIF-8 and Mn3O4 nanoenzymes anchored on the surface of ZIF-8, forming an SOD@ZIF-8 / Mn3O4 complex. 2.The SOD@ ZIF-8 / Mn3O4 composite nanomaterial of claim 1, characterized in that, The Mn3O4 nanozyme, after being surface-functionalized with citric acid, is anchored to the ZIF-8 surface through self-assembly.

3. The preparation method of the SOD@ZIF-8 / Mn3O4 composite nanomaterial as described in claim 1 or 2, characterized in that, Includes the following steps: (1) Synthesis of Mn3O4 nanoparticles; (2) The SOD packet is embedded in ZIF-8 to obtain SOD@ZIF-8; (3) Mix the Mn3O4 nanoparticles obtained in step (1) with the SOD@ZIF-8 obtained in step (2) to form SOD@ZIF-8 / Mn3O4 composite nanomaterials by self-assembly.

4. The preparation method according to claim 3, characterized in that, In step (1), the method for synthesizing the Mn3O4 nanoparticles is as follows: Mn(OAc)2·4H2O is dissolved in DMF and reacted in a high-pressure reactor at 120-140℃ for 6-10 h. After centrifugation, washing, and freeze-drying, Mn3O4 nanoparticles are obtained.

5. The preparation method according to claim 3, characterized in that, In step (2), the preparation method of SOD@ZIF-8 is as follows: SOD is dissolved in a methanol solution containing 2-methylimidazole, a methanol solution containing Zn(NO3)2·6H2O is added, the mixture is stirred at room temperature, the precipitate is collected by centrifugation, and SOD@ZIF-8 is obtained after washing.

6. The preparation method according to claim 3, characterized in that, In step (3), the Mn3O4 nanoparticles are first surface functionalized with citric acid solution before being mixed with SOD@ZIF-8.

7. The use of the SOD@ZIF-8 / Mn3O4 composite nanomaterial as described in claim 1 or 2 in the preparation of a drug for treating acetaminophen-induced acute liver injury.

8. The application according to claim 7, characterized in that, The SOD@ZIF-8 / Mn3O4 composite nanomaterials achieve multi-target synergistic protection against liver injury by scavenging reactive oxygen species, inhibiting lipid peroxidation, blocking ferroptosis, and / or inhibiting the expression of inflammatory factors.

9. A drug for treating acetaminophen-induced acute liver injury, characterized in that, Includes the SOD@ZIF-8 / Mn3O4 composite nanomaterial as described in claim 1 or 2.

10. The medicament according to claim 9, characterized in that, It also includes pharmaceutically acceptable carriers.

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