Metal organic framework material, preparation method and application thereof

Abstract

The application discloses a kind of metal organic framework material and its preparation method and application, wherein, preparation method includes the following preparation steps: zinc acetate, phycocyanin is dissolved in water, and mixed solution is prepared;Mixed solution is added to 2-methyl imidazole aqueous solution mixing stirring, centrifugation, and the precipitate is washed with water, dispersed in water, and nanoparticle dispersion is prepared;Nanoparticle dispersion, epigallocatechin gallate and manganese chloride are added to water mixing stirring, centrifugation, and the precipitate is washed with water, dispersed in water, and metal organic framework material is prepared.The metal organic framework material prepared by the application has free radical scavenging antioxidant capacity;It has anti-inflammatory effect, can reduce liver damage and necrosis, and is suitable for the treatment of acute liver injury;It also has the effects of regulating inflammatory response, promoting macrophage transformation and inhibiting T cell activation, and is suitable for immune regulation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal organic framework, in particular to a kind of metal organic framework material and its preparation method and application. BACKGROUND

[0002] Acute liver injury (ALI) refers to a kind of clinical disease that patients without liver disease or with liver disease in stable state appear liver function acute deterioration in short term after exposure to liver injury hazard factors (such as drugs, toxins, infection, etc.). Its main pathological manifestations are severe damage of liver function and structure, which is derived from the violent outbreak of reactive oxygen species (ROS) of hepatocytes. The increase of reactive oxygen species can lead to oxidative stress of hepatocytes, and then cause lipid peroxidation of cell membrane, protein denaturation and DNA damage, and finally lead to necrosis and apoptosis of hepatocytes. For the treatment of ALI, it mainly includes stopping using suspected liver-damaging drugs, liver protection, anti-inflammatory and antioxidant therapy, etc.

[0003] Nanomedicine can selectively accumulate in liver due to its unique physical and chemical properties, such as small size, high specific surface area and good biocompatibility, which can promote targeted therapeutic intervention and show broad prospects in the treatment of ALI. SUMMARY

[0004] The purpose of the present application is to avoid the shortcomings in the prior art and provide a kind of metal organic framework material and its preparation method and application. Zinc acetate is used to encapsulate phycocyanin, and then mixed with epigallocatechin gallate and manganese chloride to obtain metal organic framework material. The prepared metal organic framework material has good stability and is suitable for in vitro antioxidant, treatment of acute liver injury and immunoregulation.

[0005] To achieve the above purpose, the present application provides a kind of metal organic framework material preparation method, which comprises the following steps:

[0006] Zinc acetate and phycocyanin are dissolved in water to obtain a mixed solution;

[0007] The mixed solution is added to the 2-methyl imidazole aqueous solution and stirred, centrifuged, and the precipitate is washed with water and dispersed in water to obtain a nanoparticle dispersion;

[0008] The nanoparticle dispersion, epigallocatechin gallate and manganese chloride are added to water and stirred, centrifuged, and the precipitate is washed with water and dispersed in water to obtain a metal organic framework material.

[0009] Further, the mass ratio of zinc acetate to phycocyanin is 5:1-2.

[0010] Further, the mass ratio of phycocyanin to 2-methyl imidazole is 1-2:0.2.

[0011] Further, the 2-methylimidazole aqueous solution has a concentration of 90-110 mg / mL.

[0012] Further, the mass ratio of the epigallocatechin gallate to the manganese chloride is 2-3:1.

[0013] The application further provides a metal organic framework material prepared by the preparation method of the metal organic framework material.

[0014] The application further provides an application of the metal organic framework material, and the metal organic framework material is used for in-vitro antioxidation.

[0015] The application further provides an application of the metal organic framework material, and the metal organic framework material is used for the treatment of acute liver injury.

[0016] The application further provides an application of the metal organic framework material, and the metal organic framework material is used for immunoregulation.

[0017] The metal organic framework material preparation method has the following beneficial effects:

[0018] The metal organic framework material is prepared by a simple method, has high stability and is not easy to be decomposed, is suitable for biological medicine, has excellent free radical scavenging and antioxidant properties, is suitable for in-vitro antioxidant, can reduce the apoptosis of liver tissue cells, relieve the damage and death of liver tissue, has excellent anti-inflammatory capacity and is suitable for the treatment of acute liver injury, and can promote the M1-M2 transformation of macrophages, inhibit the maturation of dendritic cells, block the transmission of antigens, inhibit the activation of T cells and be applied to immunoregulation. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 FIG. 1 is a transmission electron microscope image and a HAADF image of PC-Mn@EGCG; the scale = 200 nm.

[0020] Figure 2 FIG. 1 is a transmission electron microscope image and a HAADF image of PC-Mn@EGCG; the scale = 200 nm.

[0021] Figure 3 FIG. 4 is the free radical scavenging capacity of PC-Mn@EGCG.

[0022] Figure 4 FIG. 4 is the free radical scavenging capacity of PC-Mn@EGCG.

[0023] Figure 5Figure of mouse serum ALT and AST results of Example 5; n=6; *p<0.05, **p<0.01, ****p<0.0001;

[0024] Figure 6 Figure of H&E staining and statistical results of hepatocyte necrosis area of Example 5; n=4; ****p<0.0001, scale bar=100 μm;

[0025] Figure 7 Figure of ELISA detection of mouse serum inflammatory factor levels of Example 5; n=6; **p<0.01, ***p<0.001, ****p<0.0001;

[0026] Figure 8 Figure of qRT-PCR detection of mouse liver inflammatory factor and anti-inflammatory factor levels of Example 6; n=3-6; *p<0.05, **p<0.01, ***p<0.001;

[0027] Figure 9 Figure of flow cytometry analysis results and statistics of Example 6; **p<0.01, ***p<0.001, ****p<0.0001. DETAILED DESCRIPTION

[0028] Preferred embodiments of the present application will be described in more detail by making reference to the accompanying drawings. Even though preferred embodiments of the present application are shown in the drawings, it is to be understood that the present application can be carried out in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided in order to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0029] The application provides a preparation method of a metal organic framework material, comprising:

[0030] Zinc acetate and phycocyanin are dissolved in water at a mass ratio of 5:1-2 to prepare a mixed solution;

[0031] The mixed solution is added to a 2-methylimidazole aqueous solution with a concentration of 90-110 mg / mL and mixed and stirred, centrifuged, and the precipitate is washed with water and dispersed in water to obtain a nanoparticle dispersion; the mass ratio of the phycocyanin and the 2-methylimidazole is 1-2:0.2;

[0032] The nanoparticle dispersion, epigallocatechin gallate, and manganese chloride are added to water and mixed and stirred, centrifuged, and the precipitate is washed with water and dispersed in water to prepare a metal organic framework material; the mass ratio of the epigallocatechin gallate and the manganese chloride is 2-3:1;

[0033] The application also provides the metal organic framework material prepared by the method, the electromotive potential value of the metal organic framework material is less than -30 mV, the metal organic framework material has good stability, and can be used for in-vitro antioxidant, acute liver injury treatment and immune regulation of the body.

[0034] Example 1: Preparation of a metal organic framework material

[0035] S1: 10 mg of zinc acetate and 3 mg of phycocyanin were weighed and dissolved in 6 mL of water to prepare a mixed solution;

[0036] In this embodiment, the mass ratio of zinc acetate and phycocyanin is 10:3.

[0037] S2: The mixed solution was added to the 2-methylimidazole aqueous solution during stirring, and stirring was continued for 50 min, and the precipitate was collected by centrifugation at 5000 relative centrifugal force (RCF) for 10 min; the precipitate was dissolved with 5 mL of pure water, centrifuged at 5000 RCF for 10 min, and water washing was repeated for 3 times; the precipitate was dissolved with 10 mL of water to prepare a nanoparticle dispersion liquid;

[0038] In this embodiment, the mass ratio of phycocyanin and 2-methylimidazole is 3:0.4.

[0039] In this embodiment, the concentration of the 2-methylimidazole aqueous solution is 100 mg / mL, and the preparation method is as follows: 400 mg of 2-methylimidazole is dissolved in 4 mL of water.

[0040] S3: 1 mL of the nanoparticle dispersion liquid was added to 2 mL of water and 1 mL of epigallocatechin gallate (EGCG), 100 μl of manganese chloride (10 mg / mL) (2.5 mg / mL) was added, and stirring was performed for 5 min; centrifugation was performed, the precipitate was washed with water for 3 times, the precipitate was dissolved with 5 mL of water, and a metal organic framework material (PC-Mn@EGCG) was prepared.

[0041] In this embodiment, the mass ratio of epigallocatechin gallate and manganese chloride is 2.5:1.

[0042] The PC-Mn@EGCG prepared in Example 1 was subjected to transmission electron microscope (TEM) and high-angle annular dark field imaging (HAADF) spectrum analysis:

[0043] As Figure 1As shown, the TEM image of PC-Mn@EGCG prepared in Example 1 illustrates the morphology of PC-Mn@EGCG. HAADF spectral analysis reveals the distribution of elements in PC-Mn@EGCG. The distribution patterns of C (red), N (green), O (blue), Mn (yellow), and Zn (orange) in the HAADF spectral analysis are consistent with the morphology shown in the TEM image of PC-Mn@EGCG, and each element is uniformly distributed within the PC-Mn@EGCG morphology. This indicates that PC-Mn@EGCG was successfully constructed.

[0044] Stability test of PC-Mn@EGCG prepared in Example 1:

[0045] like Figure 2 As shown in the figure, the zeta potential (Zeta) plot of PC-Mn@EGCG shows a single peak at -30.43 mV on the horizontal axis, exhibiting a normal distribution, indicating that the Zeta potential value of PC-Mn@EGCG is -30.43 mV. A higher Zeta potential indicates stronger repulsive force between particles and better system stability. The PC-Mn@EGCG prepared in this embodiment has an absolute Zeta potential of 30.43 mV, demonstrating good stability and thus beneficial for biomedical applications.

[0046] Example 2: Preparation of Metal-Organic Framework Materials

[0047] S1: Weigh 10 mg of zinc acetate and 2 mg of phycocyanin and dissolve them in 6 mL of water to prepare a mixed solution;

[0048] In this embodiment, the mass ratio of zinc acetate to phycocyanin is 5:1.

[0049] S2: During stirring, the mixed solution was added to the 2-methylimidazole aqueous solution, and stirring was continued for 50 min. The mixture was then centrifuged at 5000 relative centrifugal force (RCF) for 10 min, and the precipitate was collected. The precipitate was dissolved in 5 mL of pure water, centrifuged at 5000 RCF for 10 min, and washed with water three times. The precipitate was then dissolved in 10 mL of water to obtain a nanoparticle dispersion.

[0050] In this embodiment, the mass ratio of phycocyanin to 2-methylimidazole is 1:0.2;

[0051] In this embodiment, the mass ratio of zinc acetate, phycocyanin, and 2-methylimidazole is 10:2:0.4;

[0052] In this embodiment, the concentration of the 2-methylimidazole aqueous solution is 90 mg / mL, and the preparation method is as follows: weigh 400 mg of 2-methylimidazole and dissolve it in 4 mL of water;

[0053] S3: Take 1 mL of the nanoparticle dispersion liquid, add 2 mL of water and 1 mL of epigallocatechin gallate (EGCG) (3 mg / mL), add 100 μl of manganese chloride (10 mg / mL), stir for 5 min; centrifuge, wash the precipitate with water three times, dissolve the precipitate with 5 mL of water to prepare a metal-organic framework material (PC-Mn@EGCG);

[0054] In this embodiment, the mass ratio of epigallocatechin gallate to manganese chloride is 3:1.

[0055] Example 3 Preparation of metal-organic framework material

[0056] S1: Weigh 10 mg of zinc acetate and 4 mg of phycocyanin and dissolve them in 6 mL of water to prepare a mixed solution;

[0057] In this embodiment, the mass ratio of zinc acetate to phycocyanin is 5:2

[0058] S2: During stirring, the mixed solution is added to the 2-methylimidazole aqueous solution, and stirring is continued for 50 min. Centrifuge at 5000 relative centrifugal force (RCF) for 10 min, and collect the precipitate; dissolve the precipitate with 5 mL of pure water, centrifuge at 5000 RCF for 10 min, and repeat the water washing for 3 times; dissolve the precipitate with 10 mL of water to prepare a nanoparticle dispersion liquid;

[0059] In this embodiment, the mass ratio of phycocyanin to 2-methylimidazole is 1:0.1;

[0060] In this embodiment, the concentration of the 2-methylimidazole aqueous solution is 100 mg / mL, and the preparation method is as follows: weigh 400 mg of 2-methylimidazole and dissolve it in 4 mL of water;

[0061] S3: Take 1 mL of the nanoparticle dispersion liquid, add 2 mL of water and 1 mL of epigallocatechin gallate (EGCG) (3 mg / mL), add 100 μl of manganese chloride (10 mg / mL), stir for 5 min; centrifuge, wash the precipitate with water three times, dissolve the precipitate with 5 mL of water to prepare a metal-organic framework material (PC-Mn@EGCG);

[0062] In this embodiment, the mass ratio of epigallocatechin gallate to manganese chloride is 3:1.

[0063] Example 4 PC-Mn@EGCG for in vitro antioxidant

[0064] The PC-Mn@EGCG prepared in Example 1 was formulated into solutions with concentrations of 10 μg / mL, 20 μg / mL, 40 μg / mL, 80 μg / mL, 120 μg / mL, and 160 μg / mL. The ABTS radical scavenging rates of PC-Mn@EGCG at different concentrations were calculated, and the results are shown in Figure Figure 3 A. The DPPH radical scavenging rates of PC-Mn@EGCG at different concentrations were calculated, and the results are shown in Figure Figure 3 B. The superoxide anion (O2 - ) radical scavenging rates of PC-Mn@EGCG at different concentrations were calculated, and the results are shown in Figure Figure 3 C.

[0065] In combination Figure 3 It can be seen that PC-Mn@EGCG can effectively scavenge ABTS radicals in a concentration-dependent manner. Specifically, as the concentration of PC-Mn@EGCG increases, the ABTS scavenging rate increases. When the concentration of PC-Mn@EGCG increases from 20 μg / mL to 160 μg / mL, the ABTS elimination rate rapidly increases from 14% to 83%.

[0066] Similarly, when the concentration of PC-Mn@EGCG reaches 160 μg / mL, the DPPH scavenging rate also reaches 35%, and shows obvious concentration dependence.

[0067] In addition, PC-Mn@EGCG also shows excellent scavenging effect on superoxide anion (O2 - ) radicals. At a concentration of 10 μg / mL, the scavenging rate can reach 75%. These results fully demonstrate that PC-Mn@EGCG has excellent and rapid radical scavenging ability.

[0068] To further verify the antioxidant performance of PC-Mn@EGCG, this example uses electron spin resonance (ESR) technology to capture hydroxyl radicals (•OH), superoxide anion (O2 - ) adducts and DPPH radicals. The signal intensity and peak area in the ESR spectrum are directly proportional to the concentration of free radicals, so the integral peak area is used to realize the quantitative analysis of free radicals. Specifically, the stronger the signal and the larger the peak area, the more free radicals there are. The results are shown in Figure Figure 4 In the spectrum of this example, the hydroxyl radical (•OH), superoxide anion (O2 - ) adduct and DPPH radical signals after the addition of PC-Mn@EGCG are marked in red.

[0069] As shown in Figure Figure 4As shown in A, in the presence of PC-Mn@EGCG, the ESR signal peak of hydroxyl radical (·OH) is significantly reduced, which intuitively reflects the high efficient scavenging ability of PC-Mn@EGCG to ·OH. Figure 4 As shown in B, with the addition of PC-Mn@EGCG, the O2· - The peak intensity of adduct is also weakened, which indicates that O2· - The adduct is effectively consumed. Figure 4 As shown in C, under the action of PC-Mn@EGCG, the ESR signal peak of DPPH· also appears a significant decline, which further confirms the excellent scavenging ability of PC-Mn@EGCG to DPPH·.

[0070] In summary, PC-Mn@EGCG in this embodiment exhibits excellent multiple antioxidant properties in the in vitro scavenging of various free radicals, and can be used for in vitro antioxidant.

[0071] Example 5 PC-Mn@EGCG for acute liver injury treatment

[0072] Blank control group: the mice are not induced by APAP, and no PC-Mn@EGCG is administered, such as Figure 5 The first column (indicated as APAP- and PC-Mn@EGCG- in the figure) shows;

[0073] Induction control group: the mice are induced by APAP, and no PC-Mn@EGCG is administered, such as Figure 5 The second column (indicated as APAP+ and PC-Mn@EGCG- in the figure) shows;

[0074] Dosing experimental group: the mice are induced by APAP, and PC-Mn@EGCG is administered, such as Figure 5 The third column (indicated as APAP+ and PC-Mn@EGCG+ in the figure) shows; the concentration of PC-Mn@EGCG is 160 μg / mL.

[0075] In order to explore the treatment effect of PC-Mn@EGCG on acute liver injury (ALI), this embodiment constructs an APAP-induced mouse acute liver injury model. In the pathogenesis of acute liver injury, the expression levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum will significantly increase, so ALT and AST can be used to evaluate the liver health status and liver function level.

[0076] The results are as follows Figure 5As shown, the ALT and AST levels in the serum of the blank control group mice were at a low level, and the serum ALT and AST levels of the induction control group mice were significantly increased, which indicated that APAP successfully induced severe damage to the liver. In contrast to the control group, the transaminase (ALT, AST) levels of the mice after PC-Mn@EGCG administration were significantly reduced. The results showed that PC-Mn@EGCG could effectively improve the abnormal transaminase (ALT, AST) levels of mice induced by APAP, thereby having a relieving effect on acute liver injury.

[0077] To further explore the protective effect of PC-Mn@EGCG on ALI, this embodiment carried out pathological evaluation of the liver tissues of the three experimental groups of mice, observed the liver tissue structure by H&E staining method, and directly evaluated the health status of the mouse liver, and the results are shown in Figure 6 .

[0078] Figure 6 As can be seen, the liver tissue structure of the blank control group remained intact, and no obvious damage was observed. The liver tissue structure of the induction control group mice was loose, the cell outline was blurred and unclear, and there were obvious necrotic areas of the tissue (marked with a dashed line in the figure), showing obvious cell damage. After PC-Mn@EGCG treatment, the liver cell outline of the administration experimental group mice was relatively clear, and the necrotic area of the liver was significantly reduced compared with the induction control group. Figure 6 B also shows that the apoptosis area of the induction control group is abnormally increased compared with the blank control group, and after PC-Mn@EGCG treatment, the apoptosis area of the administration experimental group is significantly reduced. It is shown that PC-Mn@EGCG can effectively reduce liver tissue damage and necrosis during acute liver injury.

[0079] Based on the above results, PC-Mn@EGCG showed a significant protective effect in the APAP-induced acute liver injury model, and played a therapeutic role in liver damage.

[0080] To further evaluate the anti-inflammatory ability of PC-Mn@EGCG in vivo, this embodiment detected the content of inflammatory factors (IL-6, TNF-α, MCP-1 and IL-1β) in the serum of mice by Enzyme-Linked Immunosorbent Assay (ELISA) method, and evaluated the inflammatory reaction in the serum of mice, and the results are shown in Figure 7 .

[0081] Figure 7It can be seen that the serum of healthy mice in the blank control group is at a very low level of IL-6, TNF-a, MCP-1 and IL-1b; after APAP induction, the serum of mice in the induction control group is abnormally increased in inflammatory factors (IL-6, TNF-a, MCP-1 and IL-1b); after PC-Mn@EGCG administration, the serum of mice in the administration experimental group is significantly reduced in inflammatory factors. It is proved that PC-Mn@EGCG can inhibit the inflammatory response of mice, thereby playing a hepatoprotective role.

[0082] Example 6 PC-Mn@EGCG for immune regulation

[0083] Blank control group: the mice are not induced by APAP, and no PC-Mn@EGCG administration is performed, such as Figure 5 the first column (APAP- and PC-Mn@EGCG - in the figure) shows;

[0084] Induction control group: the mice are induced by APAP, and no PC-Mn@EGCG administration is performed, such as Figure 5 the second column (APAP+ and PC-Mn@EGCG - in the figure) shows;

[0085] Administration experimental group: the mice are induced by APAP, and PC-Mn@EGCG administration is performed, such as Figure 5 the third column (APAP+ and PC-Mn@EGCG+ in the figure) shows; the concentration of PC-Mn@EGCG is 160 pg / mL.

[0086] The mRNA expression levels of pro-inflammatory factors (IL-6, TNF-a, MCP-1 and IL-1b) and anti-inflammatory factors (CD206) in the liver of mice were detected.

[0087] The results are shown in Figure 8 At the mRNA level, compared with the blank control group, APAP significantly increased the expression of IL-6, TNF-a and IL-1b, and after PC-Mn@EGCG administration, the expression level of the above pro-inflammatory cytokines in the liver was reduced.

[0088] In addition, APAP treatment resulted in a significant decrease in the expression level of anti-inflammatory factors (CD206) in the liver of mice compared with the blank control group. After PC-Mn@EGCG treatment, the expression level of CD206 increased significantly. These results show that PC-Mn@EGCG effectively regulates the inflammatory response by inhibiting the expression of pro-inflammatory factors and promoting the production of anti-inflammatory factors.

[0089] To study the immune effect in vivo, the mice in the blank control group, the induction control group and the administration experimental group were euthanized, and the spleen cells were extracted and analyzed by flow cytometry. When ALI occurs, the body can recognize Pathogen-Associated Molecular Patterns (PAMPs) and Damage-Associated Molecular Patterns (DAMPs). The recognition of these molecular patterns triggers a series of inflammatory responses, leading to the recruitment and activation of macrophages in the liver, promoting the M1-M2 conversion of macrophage phenotype, and then triggering inflammation. Therefore, the phenotype of macrophages was labeled in this embodiment, and CD86 (a marker of M1 macrophages) was used for immunofluorescence staining. As shown in 9A-B, the expression of CD86 in the spleen of the blank control group mice was low, the expression of CD86 in the induction control group mice treated with APAP increased, and the expression of CD86 in the administration experimental group mice treated with PC-Mn@EGCG decreased. It is shown that PC-Mn@EGCG can inhibit the expression of M1 macrophages in the spleen of mice with liver injury, and promote the transformation of M1 macrophages.

[0090] In addition, T cells are divided into two core subtypes of CD4 + (helper T cells) and CD8 + (cytotoxic T cells) according to surface markers, and CD8 + T cells express CD8 co-receptors on the surface, and initial CD8 + T cells need to be activated by antigen presentation of dendritic cells (DCs) to differentiate into effector cytotoxic T cells (CTLs) or memory T cells, and CTLs maintain the body's defense balance through direct killing and immune regulation. Therefore, the maturation of dendritic cells can be determined by the expression level of CD4 and CD8, and specifically, when the expression of CD4 and CD8 increases, the number of mature dendritic cells also increases.

[0091] As Figure 9 C-F, the expression of CD4 and CD8 in the blank control group mice was at a low level, the expression of CD4 and CD8 in the induction control group mice treated with APAP increased, and the expression of CD4 and CD8 in the administration experimental group mice treated with PC-Mn@EGCG decreased. It is shown that when the mice are in APAP, the number of mature DCs in the body increases, and the administration of PC-Mn@EGCG can inhibit the maturation of DCs, so that they are in an immature state of immune tolerance. These DCs with immune tolerance are called tolerogenic DCs (tDCs), and the tDCs can inhibit the excessive immune activation of APAP mice.

[0092] DC as a professional antigen-presenting cell, constitutively expresses or highly expresses CD80 after activation; part of activated T cells can also express CD80, so CD80 is an important immune costimulatory molecule. Therefore, the expression level of CD80 and CD86 can reflect the activation degree of T cells. NKp46 belongs to the immunoglobulin superfamily, and the expression level of NKp46 and Grl can also reflect the activation degree of the immune mechanism.

[0093] Figure 9 As shown in G-H, the expression levels of CD80 and CD86 in the administration experiment group are lower than those in the induction control group, indicating that PC-Mn@EGCG reduces the expression of CD80 and CD86, reduces the costimulatory signal of T cells, thereby inhibiting the activation and proliferation of T cells, and helps to control excessive immune response. Similarly, the expression levels of NKP46 and Grl in the administration experiment group are lower than those in the induction control group, indicating that PC-Mn@EGCG can also inhibit the expression of NKP46 and Grl, further inhibiting the excessive activation of the immune system.

[0094] In summary, PC-Mn@EGCG can regulate the inflammatory response of APAP-treated mice, promote the transformation of M1 macrophages, inhibit the activation of dendritic cells, and inhibit the excessive activation of the immune system. Therefore, PC-Mn@EGCG is suitable for immune regulation.

[0095] It can be understood that the above embodiments only express the preferred embodiments of the present application, which are described in detail and specifically, but cannot be understood as a limitation on the scope of the patent of the present application; it should be pointed out that for ordinary skilled in the art, the above technical features can be freely combined without departing from the concept of the present application, and several modifications and improvements can be made, which belong to the protection scope of the present application; therefore, any equivalent transformation and modification within the scope of the claims of the present application shall belong to the scope of the claims of the present application.

Claims

1. A method of preparing a metal organic framework material, characterized in that, The method comprises the following steps: dissolving zinc acetate and phycocyanin in water to obtain a mixed solution; the mass ratio of zinc acetate to phycocyanin is 5:1-2; adding the mixed solution into an aqueous 2-methylimidazole solution, mixing and stirring, centrifuging, washing the precipitate with water, dispersing in water to obtain a nanoparticle dispersion; the mass ratio of phycocyanin to 2-methylimidazole is 1-2:0.2; adding the nanoparticle dispersion, epigallocatechin gallate and manganese chloride into water, mixing and stirring, centrifuging, washing the precipitate with water, dispersing in water to obtain a metal-organic framework material; the mass ratio of epigallocatechin gallate to manganese chloride is 2-3:

1.

2. The method of claim 1, wherein the metal organic framework material is prepared by the method comprising: The concentration of the aqueous 2-methylimidazole solution is 90-110 mg / mL. ​ 3. A metal organic framework material, characterized in that, The metal-organic framework material is prepared by the method of any one of claims 1-2.

4. Use of a metal organic framework material, characterized in that The metal-organic framework material of claim 3 is used for in-vitro antioxidant.

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