A metal-organic framework material for chelating alpha nuclide, its preparation method and application in antitumor drugs

Abstract

This invention belongs to the field of biomedical technology, specifically relating to a metal-organic framework material for chelating α-nucleotides, its preparation method, and its application in antitumor drugs. The preparation method of the metal-organic framework material involves dissolving ferric chloride tetrahydrate and 2,5-dihydroxy-1,4-benzenediacarboxylic acid in an organic solvent at a molar ratio of 2:3, and reacting at 105°C for 24 hours. The key to this invention is that the metal-organic framework material serves as a novel... 223 The Ra chelation platform can achieve [the desired effect] without relying on traditional chelation mechanisms. 223 The efficient capture and stable loading of Ra effectively solves the chelation problem caused by the intrinsic properties of Ra²⁺ ions, and improves... 223 Ra radiopharmaceuticals offer stability and targeting capabilities, and significantly reduce the risk of radiation exposure to non-target organs.

Description

Technical Field

[0001] This invention belongs to the field of biomedical technology, specifically relating to a metal-organic framework material for chelating α-nucleotides, its preparation method, and its application in antitumor drugs. Background Technology

[0002] Radium-223 ( 223 Ra is the world's first approved alpha-based radiopharmaceutical, demonstrating significant efficacy in the treatment of bone metastases from prostate cancer. Its high linear energy transfer (LET), short range, and hypoxia tolerance allow it to efficiently induce irreparable DNA double-strand breaks (DSBs) in tumor cells, achieving precise killing of tumor cells while protecting surrounding healthy tissue. However, Ra... 2+ The large ionic radius and low charge density weaken the electrostatic binding between the ionic compound and the chelating agent, resulting in insufficient stability of the complex in vivo, which severely limits the expansion of clinical applications and the improvement of efficacy.

[0003] To promote 223 For targeted alpha therapy of Ra, Oak Ridge National Laboratory in the United States has developed a novel 21-membered macrocyclic ligand, macropa-XL, for chelation therapy. 223 Ra 2+ However, due to the loss of free energy, its effect on... 223 Ra 2+ The affinity for the ion remains low, and the stability of the complex is poor. This "chelation problem" caused by the intrinsic properties of the ion urgently needs to be solved, and a new type of efficient carrier that does not rely on traditional strong electrostatic interactions is urgently needed. Summary of the Invention

[0004] The purpose of this invention is to provide a metal-organic framework material for chelating α-nucleotides, its preparation method, and its application in antitumor drugs. This metal-organic framework material achieves chelation of α-nucleotides through its unique structural features. 2+ Its efficient capture and stable payload provide a carrier basis for targeted tumor therapy and effectively reduce the risk of radiation exposure to non-target organs.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for preparing a metal-organic framework material for chelating α nuclides includes: dissolving ferric chloride tetrahydrate and 2,5-dihydroxy-1,4-benzenediacarboxylic acid in an organic solvent at a molar ratio of 2:3, heating to 105°C using an oil bath heating method, reacting for 24 hours, and centrifuging to separate the dark brown metal-organic framework material.

[0007] The metal-organic framework material prepared by this invention possesses: a highly tunable nanoporous structure, precisely matching the size of specific ions; a surface rich in negatively charged sites, generating strong electrostatic attraction for target ions; and high-density Fe... 3+ The presence of unsaturated coordination sites enhances adsorption capacity through ion exchange mechanisms; its high specific surface area provides a structural basis for the distribution of multiple active sites. It can achieve adsorption without relying on traditional strong electrostatic chelation mechanisms. 223 Ra 2+ This multi-action mechanism overcomes the challenges of efficient load capture and stable load management. 223 The chelation problem caused by the intrinsic properties of Ra improves the stability and targeting of radiopharmaceuticals and significantly reduces the risk of radiation exposure to non-target organs.

[0008] Utilizing the highly tunable nanopore structure, surface negative charge sites, and high-density Fe of the aforementioned metal-organic framework materials 3+ Coordination unsaturated sites are used to achieve adsorption via ion exchange. 223 Ra 2+ The efficient capture and stable loading of metal-organic framework materials with... 223 Ra 2+ Ions can be obtained by contacting the solution phase. 223 Ra radioactive nanomedicine.

[0009] Combination 223 Ra's alpha particle radiation and Fe 3+ The chemodynamic therapy (CDT) effect of catalyzing the generation of hydroxyl radicals (·OH) from H2O2 forms a synergistic mechanism of dual action of "α-radiation-chemokinetics". The two effects work together to significantly amplify the DNA damage and oxidative stress levels of tumor cells, overcoming the efficiency bottleneck of single therapy.

[0010] Combined use 223 Ra-based radioactive nanomedicines and anti-PD-L1 drugs can significantly enhance the intensity and persistence of anti-tumor immune responses. Anti-PD-L1 drugs block the PD-1 / PD-L1 pathway, reducing immune escape from tumor cells and making the immune response induced by Ra-based radioactive nanomedicines more effective. The pan-apoptotic release of large amounts of tumor antigens induced by Ra-based radioactive nanomedicines, while anti-PD-L1 drugs enhance T cell activation, and the synergistic effect of both significantly improves therapeutic efficacy. Experiments show that they can not only effectively inhibit primary tumors but also significantly inhibit distant tumors, achieving a systemic anti-tumor effect. Attached Figure Description

[0011] Figure 1 This is a TEM image of Fe-MOF-74.

[0012] Figure 2HAADF image of Fe-MOF-74.

[0013] Figure 3 The image shows the surface distribution of EDS elements in Fe-MOF-74.

[0014] Figure 4 The image shows the energy dispersive spectroscopy (EDS) spectrum of Fe-MOF-74.

[0015] Figure 5 DLS image of Fe-MOF-74.

[0016] Figure 6 The XRD pattern of Fe-MOF-74.

[0017] Figure 7 a is the XPS spectrum of Fe-MOF-74. Figure 7 b is the XPS spectrum of Fe 2p. Figure 7 c is the XPS spectrum of O 1s. Figure 7 d is the XPS spectrum of C 1s.

[0018] Figure 8 for 223 Radiolabeling rate of Ra / Fe-MOF-74.

[0019] Figure 9 for 223 Radiolabeled stability diagram of Ra / Fe-MOF-74.

[0020] Figure 10 for 223 Structural optimization diagram of Ra / Fe-MOF-74.

[0021] Figure 11 for 223 Energy change diagram of Ra / Fe-MOF-74 peroxidase simulated activity.

[0022] Figure 12 for 223 ·OH production of Ra / Fe-MOF-74 over time.

[0023] Figure 13 for 223 ·OH production of Ra / Fe-MOF-74 as a function of pH value.

[0024] Figure 14 for 223 ·OH production of Ra / Fe-MOF-74 as a function of H2O2 concentration.

[0025] Figure 15 for 223 Ra and 223Results of Ra / Fe-MOF-74 cell uptake experiment.

[0026] Figure 16 a is 223 Ra CCK-8 cytotoxicity assay results Figure 16 b is 223 Cytotoxicity test results of Ra / Fe-MOF-74.

[0027] Figure 17 The results of cell live / dead staining experiments for different groups are shown.

[0028] Figure 18 The results show the levels of intracellular reactive oxygen species in different groups.

[0029] Figure 19 The results of mitochondrial membrane potential detection for different groups.

[0030] Figure 20 a is 223 The distribution of Ra in tumor-bearing mice. Figure 20 b is 223 Distribution of Ra / Fe-MOF-74 in tumor-bearing mice.

[0031] Figure 21 The results show the tumor volume measurement of a single tumor-bearing mouse.

[0032] Figure 22 a represents the average change curve of the relative tumor volume (V / V0) of tumor-bearing mice over time. Figure 22 b represents the weight change results of tumor-bearing mice.

[0033] Figure 23 The survival time curves are for different groups of tumor-bearing mice.

[0034] Figure 24 HE staining results for tumor tissues in each group.

[0035] Figure 25 The results of TUNEL staining of tumor tissue.

[0036] Figure 26 Immunohistochemistry (IHC) was used to detect the expression levels of AIM2, GSDMD, and Cleaved Caspase-1 in tumor tissues of each group.

[0037] Figure 27 The expression level of Cleaved Caspase-3 in tumor tissues of each group was detected by IHC.

[0038] Figure 28 The expression level of p-MLKL in tumor tissues of each group was detected by IHC.

[0039] Figure 29 a represents the CRT expression level in tumor tissues of each group as detected by IHC. Figure 29 b represents the expression level of HSP70 in tumor tissues of each group as detected by IHC. Figure 29 c represents the expression level of HMGB1 in tumor tissues of each group as detected by IHC. Figure 29 d represents the expression level of IL-1β in tumor tissues of each group as detected by IHC.

[0040] Figure 30 To detect CD11c in tumor tissues of each group using immunofluorescence + CD86 + The result of dendritic cells.

[0041] Figure 31 To detect CD3 in tumor tissues of each group using immunofluorescence + CD8 + Results of cytotoxic T lymphocytes.

[0042] Figure 32 This is the result of measuring the average volume of the primary tumor under combined treatment.

[0043] Figure 33 This is the result of measuring the average volume of the distal tumor under combined treatment.

[0044] Figure 34 The results show the body weight of mice under combined treatment.

[0045] Figure 35 Flow cytometry analysis and relative quantification results of mature dendritic cells within tumors.

[0046] Figure 36 Flow cytometry analysis and relative quantification results of intratumoral cytotoxic T lymphocytes.

[0047] Figure 37 Flow cytometry analysis and relative quantification results of regulatory T cells within tumors. Detailed Implementation

[0048] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0049] Example 1:

[0050] This embodiment provides a metal-organic framework material Fe-MOF-74 for chelating α-nucleotides. The preparation method of the metal-organic framework material Fe-MOF-74 includes:

[0051] Ferric chloride tetrahydrate (240 mg, 1.20 mmol) and 2,5-dihydroxy-1,4-benzenediacarboxylic acid (360 mg, 1.80 mmol) were dissolved in a mixed organic solution (16 mL N,N-dimethylformamide, 0.8 mL 2-propanol, and 0.8 mL water). The solution was then sealed in a glass bottle and heated with stirring in an oil bath at 105°C for 24 hours. After the reaction was complete, the mixture was centrifuged at 10,000 rpm for 10 minutes to separate the dark brown metal chelate Fe-MOF-74. Fe-MOF-74 was washed three times with ethanol and dispersed in 20 mL of ethanol for later use.

[0052] The morphology of Fe-MOF-74 was observed using transmission electron microscopy (TEM, JEOL 2011), such as... Figure 1 As shown, Fe-MOF-74 has a diameter of approximately 20 nanometers and exhibits excellent dispersibility.

[0053] High-angle annular dark-field (HAADF) imaging and energy-dispersive X-ray spectroscopy (EDS) elemental mapping analysis were performed using a FEI Titan Cubed Themis G2 300 transmission electron microscope. The HAADF imaging results are as follows: Figure 2 As shown, the morphology is uniform, consistent with the characteristics of Fe-MOF-74. The elemental mapping image is as follows. Figure 3 The image shows the spatial distribution of C, O, and Fe elements in Fe-MOF-74. The uniform distribution of Fe indicates that the Fe centers have been successfully integrated into the MOF matrix, while the uniform distribution of C and O, acting as organic linkers, further supports the integrity of the framework structure. Figure 4 As shown, energy dispersive spectroscopy confirmed the elemental composition of Fe-MOF-74, showing obvious C, O and Fe peaks. The detected elements were consistent with the expected composition of Fe-MOF-74.

[0054] Dynamic light scattering (DLS) was performed using a Zetasizer Nano ZS90 nanoparticle size potentiometer (Malvern Instruments, UK) to characterize the hydrated particle size distribution of Fe-MOF-74. DLS images are shown below. Figure 5 As shown, the hydrodynamic diameter of Fe-MOF-74 is 122.4 ± 50 nm.

[0055] X-ray diffraction (XRD) patterns were obtained using a Rigaku D / max 2500 diffractometer. Figure 6 As shown, the spectrum of the obtained material matches the characteristic peaks of the standard card of MOF-74, confirming its successful synthesis.

[0056] The chemical valence states and bonding environments of Fe, C, and O elements in Fe-MOF-74 were analyzed using X-ray photoelectron spectroscopy (Thermo Scientific ESCALAB 250Xi). Figure 7 As shown in figure a, X-ray photoelectron spectroscopy (XPS) data supports the presence of Fe, C, and O elements in Fe-MOF-74. Figure 7 As shown in b, XPS analysis confirmed that the Fe element in Fe-MOF-74 was Fe. 3+ Their Fe 2p binding energies are 711.84 eV and 724.81 eV, respectively. For example... Figure 7 As shown in Figure c, the O 1s spectrum exhibits two significant peaks, indicating that the oxygen atoms are in different chemical states. The first peak, located at a binding energy of 534.11 eV, is attributed to the oxygen atom bonded to carbon in a single bond (O=C). The second peak, located at 531.93 eV, is attributed to the oxygen atom forming a double bond with carbon (OC). Figure 7 As shown in Figure d, the C 1s spectrum of Fe-MOF-74 exhibits three distinct peaks in XPS analysis, indicating that the carbon atoms within the framework are in different chemical environments. The first peak, appearing at a binding energy of 288.68 eV, is attributed to the carbon atom in the OC=O structure, suggesting the presence of a carboxylate group. The second peak, at 286.22 eV, is attributed to the carbon atom (CO) bonded to oxygen via a single bond. The third peak, appearing at 284.74 eV, is attributed to the carbon atom in a typical C-C bond environment.

[0057] Example 2:

[0058] This embodiment provides a ²²³Ra radioactive nanomedicine, wherein the ²²³Ra radioactive nanomedicine is a 1 mCi radioactive nanomedicine. 223 Ra and Fe-MOF-74 prepared in Example 1 at a concentration of 1 mg / mL were stirred at room temperature for 24 hours, and the precipitate was obtained by centrifugation or ultrafiltration. 223 Ra / Fe-MOF-74.

[0059] Labeling rate and stability determination:

[0060] Evaluation on Whatman No. 1 filter paper using paper chromatography 223 Labeling rate and stability of Ra / Fe-MOF-74. The radioactivity of samples was determined using a gamma counter after incubation in PBS buffer at 37°C for different times (0 h, 15 h, 24 h, and 48 h).

[0061] like Figure 8 As shown 223 The Ra / Fe-MOF-74 labeling rate reached 98%, such as Figure 9 As shown, 223Ra / Fe-MOF-74 can maintain more than 80% of its structural stability within 48 days.

[0062] Theoretical calculations and catalytic mechanism analysis:

[0063] All density functional theory calculations were performed using the Vienna ab initio simulation software package. The exchange-correlation functional was performed using the Perdew-Burke-Ernzerhof functional under the generalized gradient approximation, with the nucleus-electron interaction handled by the projected plane-wave method. The cutoff energy of the plane-wave basis set was set to 450 eV. During structural optimization, the electronic self-consistent convergence criterion was set to 10. - 5 eV, atomic residual force limited to within 0.05 eV / Å, Brillouin zone sampling using a 1×1×1 Monkhorst-Pack k-point grid.

[0064] Based on the optimized structural model of Fe-MOF-74, theoretical calculations show that Ra atoms can be stably anchored within the material's pores, forming coordination bonds with carboxyl oxygen atoms. The Ra-O equilibrium bond lengths range from 2.60 to 2.71 Å, a value consistent with typical coordination characteristics of metal-organic frameworks, thus confirming the stable immobilization of radionuclides in the support at the atomic scale. Figure 10 Based on the optimized configuration, the decomposition pathway of H2O2 was studied, and the reaction mechanism was revealed through free energy calculations. Theoretical calculations show that 2OH*→OH*+OH is the rate-determining step, with an energy barrier of 4.08 eV. Figure 11 ).

[0065] The ability to generate ·OH was assessed using a 3,3',5,5'-tetramethylbenzidine colorimetric system: 223 Ra / Fe-MOF-74 was mixed with 1 mM H2O2 in HAc-NaAc buffer (pH 5.0), and after adding 1 mM TMB, the mixture was incubated for 5 minutes. The characteristic absorption peak at 652 nm was measured using a UV-Vis spectrophotometer. The experimental results showed that the absorbance at 652 nm increased significantly with the progress of the reaction, confirming that the material has a significant ·OH generation ability. Figure 12 ).

[0066] The influence of environmental factors was studied by adjusting the reaction conditions: the formation of ·OH under different pH values ​​(4.0, 5.0, 6.0) in the HAc-NaAc buffer system was compared, and the effect of H2O2 concentration (0.25, 0.5, 1.0 mM) on the activity was also studied.

[0067] Experimental results show that under acidic conditions simulating the tumor microenvironment, the catalytic activity of the material is significantly enhanced. Figure 13 Furthermore, the amount of ·OH generated increases in a dependent manner with increasing H2O2 concentration. Figure 14 ).

[0068] In vitro cell experiments:

[0069] Cell uptake: Lewis lung cancer cells (LLC cells) were seeded in 12-well plates at a density of 1 × 10⁶ cells per well. 5 One, incubated overnight. 223 Ra or 223 Cells were incubated with Ra / Fe-MOF-74 for varying times (0.5–36 hours). Cells were washed with PBS and lysed with 1M NaOH. The radioactivity intensity was quantified using a gamma counter to assess cellular uptake.

[0070] Cytotoxicity: LLC cells were seeded in 96-well plates at a density of 5 × 10⁶ cells per well. 3 Individuals were incubated overnight with different activity levels. 223 Ra or 223 After incubating with Ra / Fe-MOF-74 for 24 hours, CCK-8 reagent was added, and absorbance was measured at 450 nm to assess cytotoxicity.

[0071] LLC cells were seeded in 6-well plates and incubated overnight. They were divided into four groups: control group, Fe-MOF-74 group, ... 223 Ra group and 223 The Ra / Fe-MOF-74 groups were incubated for 24 hours after each group was treated accordingly, and then the following experiments were conducted.

[0072] Live / dead staining: Calcein AM / PI staining was used, and the staining was performed using a fluorescence microscope.

[0073] Intracellular reactive oxygen species (ROS) levels: After incubation with the DCFH-DA probe, the levels were analyzed and evaluated using fluorescence microscopy.

[0074] Mitochondrial membrane potential: Incubated with JC-1 staining working solution for 30 minutes. Subsequently, washed with PBS and observed under a fluorescence microscope.

[0075] like Figure 15 As shown, 223 Ra / Fe-MOF-74 accumulation in LLC cells was significantly higher than that in other cells. 223 Group Ra indicated a higher uptake. CCK-8 cytotoxicity assays were performed as follows... Figure 16 As shown, compared to individual processing 223 Compared to Ra, 223 Ra / Fe-MOF-74 treatment significantly increased LLC cell mortality, and the antitumor effect was dose-dependent. Figure 17 As shown, Fe-MOF-74 alone or 223 Ra-treated cells exhibited moderate cytotoxicity, while 223Ra / Fe-MOF-74 treatment resulted in the near-complete elimination of cancer cells. For example... Figure 18 As shown, in 223 In the Ra / Fe-MOF-74 group, the intracellular ROS level of LLC cells was significantly increased. Figure 19 As shown, 223 In the Ra / Fe-MOF-74 group, the mitochondrial membrane potential was significantly reduced, indicating mitochondrial damage.

[0076] The above results indicate that 223 Ra / Fe-MOF-74 exhibits significant cytotoxicity against tumor cells and effectively exerts a synergistic effect of "alpha radiation-chemodynamic therapy".

[0077] In vivo experiments:

[0078] In vivo distribution: A tumor-bearing mouse model was established using 4-6 week old female C57BL / 6 mice, and 1×10⁻⁶ mice were subcutaneously injected. 6 LLC cells. When the tumor volume reaches approximately 100 mm. 3 At that time, 200 nCi was injected intratumorally. 223 Ra / Fe-MOF-74 was used for biodistribution analysis. Tumor-bearing mice were sacrificed 18 and 24 hours after injection, and tumors and major organ tissues were collected, weighed, and their radioactivity was measured.

[0079] Therapeutic efficacy and pathological evaluation: A tumor-bearing mouse model was established. When the tumor volume reached 50-100 mm³, the mice were randomly divided into four groups: control group, Fe-MOF-74 group, 223 Ra group (intratumoral injection of 1000 nCi) and 223 Ra / Fe-MOF-74 group (intratumoral injection of 1000 nCi). Tumor size and tumor-bearing mouse weight were recorded every three days. Tumor volume was calculated using the formula (volume = width). 2 Calculated as (×length / 2). After 12 days of treatment, the tumor-bearing mice were euthanized and tumor tissue was collected for H&E staining and TUNEL histopathological examination.

[0080] Pan-apoptosis, damage-related molecular patterns, and inflammatory factor detection: To assess pan-apoptosis-related signaling pathways, immunohistochemistry (IHC) was used to detect relevant biomarkers in treated tumor tissues, including the protein expression of AIM2, GSDMD, Cleaved caspase-1, Cleaved caspase-3, and p-MLKL. To detect changes in damage-related molecular patterns (DAMPs) and inflammatory factors, IHC was used to detect the expression levels of calreticulin (CRT), heat shock protein 70 (HSP70), high-mobility histone 1 (HMGB1), and IL-1β. The expression intensity of all staining biomarkers was quantitatively analyzed using ImageJ software.

[0081] Immune activation assessment: Immunofluorescence staining was used to detect CD11c in tumor tissue sections. + CD86 + Dendritic cells and CD3 + CD8 + Distribution and proportion of cytotoxic T lymphocytes.

[0082] like Figure 20 As shown, compared to using alone 223 Compared to Ra, 223 Ra / Fe-MOF-74 exhibits a significantly prolonged retention time in tumor tissues, while its distribution in normal tissues is extremely limited. For example... Figure 21-23 As shown, in the evaluation of tumor suppression effect, the control group, Fe-MOF-74, 223 Ra and 223 The comparison results of the Ra / Fe-MOF-74 treatment groups showed that 223 The Ra / Fe-MOF-74 group exhibited the most significant tumor growth inhibition and the longest survival period. For example... Figure 24 and 25 As shown, HE and TUNEL staining results also confirmed this significant antitumor effect. Figure 26 As shown, IHC analysis revealed 223 Ra and 223 In the Ra / Fe-MOF-74 group, pan-apoptotic markers were significantly upregulated. Among them, the pyroptosis markers AIM2 and Cleaved Caspase-1 were significantly increased, especially in 223 In the Ra / Fe-MOF-74 group, AIM2 expression reached its highest level, accompanied by a significant upregulation of Cleaved Caspase-1. Meanwhile, GSDMD... 223 Ra and 223 High expression was observed in both the Ra / Fe-MOF-74 group, suggesting... 223 Ra effectively activated the GSDMD-mediated pyroptosis pathway. For example... Figure 27As shown, 223 The Ra / Fe-MOF-74 group showed significantly increased expression of cleaved caspase-3, suggesting strong activation of the apoptosis pathway. Figure 28 As shown, the necroptosis marker p-MLKL in 223 A moderate upregulation was also observed in the Ra / Fe-MOF-74 group, indicating that necrosis and apoptosis are also involved. Figure 29 As shown, further analysis revealed 223 Ra / Fe-MOF-74 treatment also significantly upregulated the expression of CRT, HSP70, and HMGB1, and promoted the secretion of IL-1β. Regarding immune cell activation, such as... Figure 30 As shown, 223 CD11c in the Ra / Fe-MOF-74 treatment group + CD86 + The number of dendritic cells increased significantly, suggesting a markedly enhanced level of dendritic cell maturation. Meanwhile, as... Figure 31 As shown, CD3 in tumor tissue + CD8 + The significant increase in the proportion of cells indicates that cytotoxic T lymphocytes (CTLs) were effectively recruited and participated in the anti-tumor immune response.

[0083] The above results indicate that 223 Ra / Fe-MOF-74 induces immunogenic cell death through panapoptosis, which not only enhances dendritic cell function but also further activates T cell-mediated immune responses, thereby exerting a potent anti-tumor effect.

[0084] Combined treatment trial:

[0085] To evaluate the therapeutic effect on local and distant tumors, LLC cells were subcutaneously injected bilaterally into C57BL / 6 mice: 1 × 10-1 cells were injected into the left side (primary tumor). 6 Cells were inoculated at 5 × 10⁶ cells on the right side (distal tumor). 5 Individual cells. When the tumor volume reaches 50-100 mm. 3 At that time, tumor-bearing mice were randomly divided into four groups: control group, 223 Ra / Fe-MOF-74 group, anti-PD-L1 group and 223 Ra / Fe-MOF-74 combined with anti-PD-L1 therapy group. The primary tumor directly received 1000 nCi. 223 Ra / Fe-MOF-74 was administered intratumorally, while anti-PD-L1 antibody was administered intraperitoneally at a dose of 75 μg per tumor-bearing mouse on days 1, 3, and 5 of the experiment. Tumor volume and weight of tumor-bearing mice were recorded every two days during the experiment.

[0086] To investigate223 The anti-tumor immune response following Ra / Fe-MOF-74 combined with PD-L1 blockade was analyzed. Tumor tissue after treatment was processed into single-cell suspensions and stained with antibodies against PerCP-CD45, FITC-CD3, PE / Cyanine7-CD4, APC-CD8a, PE-FOXP3, FITC-CD11c, APC-CD80, and PE-CD86. Flow cytometry was then used to analyze mature dendritic cells (DCs), activated T cells, and regulatory T cells (Tregs).

[0087] like Figure 32 and 33 As shown in the tumor growth curve, the tumors in the control group grew rapidly. Although anti-PD-L1 monotherapy showed some inhibitory effect on both primary and distant tumors, the efficacy was limited. In contrast, 223 Ra / Fe-MOF-74 can effectively inhibit the growth of primary tumors, but its effect on distant tumors is weak, possibly due to the inherent immune escape mechanism of tumors. 223 The combined application of Ra / Fe-MOF-74 and anti-PD-L1 showed the most significant tumor-suppressive effect, significantly inhibiting the growth of both primary and distant tumors. Figure 34 As shown, no abnormal weight loss was observed in the tumor-bearing mice receiving the combined treatment throughout the entire treatment process. Figure 35 As shown, compared with the control group, 223 Both the Ra / Fe-MOF-74 group and the anti-PD-L1 group showed an increase in the maturation level of dendritic cells (DCs) in the tumor. 223 The group treated with Ra / Fe-MOF-74 in combination with anti-PD-L1 showed the highest level of DC maturation, indicating a significantly enhanced synergistic anti-tumor immune effect. Furthermore, as... Figure 36 As shown, the combination therapy group significantly increased the overall proportion of T cells in distant tumors, with a significant increase in CTLs, which was much higher than that in the control group, the anti-PD-L1 group, or 223 Ra / Fe-MOF-74 group. Meanwhile, as... Figure 37 As shown, the number of Tregs did not change significantly, further validating the effective anti-tumor immune response induced by the combination therapy.

[0088] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A kind 223 Ra radioactive nanomedicine, characterized in that... include: Metal-organic framework materials, and chelates on said metal-organic framework materials. 223 Ra nuclide; The metal-organic framework material comprises: dissolving ferric chloride tetrahydrate and 2,5-dihydroxy-1,4-benzenediacarboxylic acid in an organic solvent at a molar ratio of 2:3, heating to 105°C using an oil bath heating method, reacting for 24 hours, and centrifuging to obtain a dark brown metal-organic framework material.

2. The one according to claim 1 223 Ra radioactive nanomedicine, characterized in that... The organic solvent is a mixed solution of N,N-dimethylformamide, 2-propanol and water.

3. A method for preparing the product according to claim 1 223 A method for Ra radioactive nanomedicine, characterized in that... include: The metal-organic framework material is reacted with a solution containing ²²³Ra²⁺ ions, and the resulting material is obtained after separation. 223 Ra radioactive nanomedicine.

4. The method according to claim 3, characterized in that, The contact reaction refers to stirring or shaking at a temperature of room temperature to 60°C for 1 to 48 hours.

5. The method according to claim 4, characterized in that, The concentration of the metal-organic framework material in the solution is 0.1~10 mg / mL.

6. The method according to claim 3, characterized in that, The solution used is ethanol.

7. A claim 1 223 Application of Ra radioactive nanomedicines in the preparation of antitumor drugs.

8. A pharmaceutical composition for treating tumors, characterized in that, include: Therapeutic effective amount as described in claim 1 223 Ra radioactive nanomedicine; And anti-PD-L1 antibody.

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