Fe / Mn porphyrin-based bimetallic organic framework as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of nano materials, and particularly relates to a Fe / Mn porphyrin-based bimetallic organic framework as well as a preparation method and application thereof. The Fe / Mn porphyrin-based bimetal organic framework FTM with Fenton-like catalytic activity, peroxidase-like activity and photodynamic performance is prepared by adopting a one-pot solvothermal method aiming at the problems of weak catalytic ability of metal ions to H2O2, limited treatment effect of a single treatment mode and the like in a tumor treatment process of monometal MOFs. In addition, FTM is used as a carrier, doxorubicin is loaded through a pi-pi stacking effect, PEG is subjected to surface modification through a Van der Waals force physical adsorption effect, and a nucleic acid aptamer capable of recognizing specific protein on the cell surface is coupled in a covalent binding mode to form the nano-composite.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterials technology, specifically relating to a Fe / Mn porphyrin-based bimetallic organic framework, its preparation method, and its application. Background Technology

[0002] Metal-organic frameworks (MOFs) are a class of porous crystalline coordination compounds that form chemical bonds between organic ligands and metal ions. They possess advantages such as high porosity, large surface area, unsaturated metal centers, and functional diversity, making them widely used in gas adsorption and separation, catalysis, sensing, and biomedicine. In 2006, Férey's research group first reported the use of MIL-100 and MIL-101 for delivering the drug ibuprofen. In recent years, to meet the diverse needs of tumor therapy, scientists have constructed various MOF-based nanomaterials. Currently, commonly used organic ligands for constructing MOFs include dimethylimidazole, tricarboxylic acids, and porphyrins. Among them, porphyrins are one of the most widely used photosensitizers in clinical practice. MOFs constructed using porphyrin molecules as organic ligands can generate large amounts of reactive oxygen species (ROS) under laser irradiation, thereby achieving effective photodynamic therapy (PDT) and inhibiting tumor growth. Simultaneously, metal ions, such as Fe... 2+ Cu + Mn 2+ MOFs can serve as active catalytic sites, giving them excellent Fenton-like catalytic activity and POD-like activity, enabling chemodynamic therapy (CDT) by catalyzing the production of •OH from H2O2. However, in tumor treatment, current MOF materials often suffer from problems such as weak catalytic ability of metal ions for H2O2 and poor efficacy of single-mode therapy.

[0003] Compared to monometallic MOFs, bimetallic metal-organic frameworks (BMOFs) have more exposed metal-active catalytic sites, enabling them to effectively catalyze H₂O₂ and thus significantly increase the production efficiency of •OH. In recent years, researchers have made considerable efforts to apply BMOFs to tumor therapy, achieving promising anti-tumor effects. In 2017, Tang Bo's research group used TCPP and Al… 3+ and Cu 2+In 2023, the Zhu Yufang research group synthesized a CuTCPP(Fe)@GOD nanosheet, which can convert endogenous H2O2 into highly toxic •OH through a Fenton-like reaction. However, PDT has low singlet oxygen production, and CDT produces little and slow •OH, resulting in the inability of single therapy to completely kill tumor cells. Furthermore, BMOFs mainly passively accumulate at the tumor site through the EPR effect, which has problems such as poor targeting and easy toxic side effects on normal tissues, thus leading to poor therapeutic effects.

[0004] In addition, patent CN117562996A discloses a biodegradable bimetallic multimodal therapeutic nanomedicine, its preparation method, and its application. This bimetallic nanomedicine utilizes Cu... 2+ and Fe 3+ Bimetallic nanomedicines Cu\Fe-TG-TCPP (DMNRs) were synthesized via a one-step hydrothermal method through coordination with organic small molecules TG and TCPP. DMNRs possess both catalase and peroxidase properties and are degradable under weakly acidic conditions, releasing Fenton-like reagents (Cu... 2+ and Fe 3+ This therapy combines photosensitizer TCPP and chemotherapy drug TG to achieve a three-modal treatment approach: PDT / CDT / CHT. However, due to the lack of targeting, the therapeutic effect is significantly limited.

[0005] Given the challenges faced in cancer treatment, integrating multiple treatment modalities and relying on active targeting technologies to achieve integrated targeted diagnosis and treatment of tumors could improve the precision of cancer treatment and reduce toxic side effects, which is a current research direction. Therefore, there is an urgent need to develop a high-performance bimetallic organic framework to achieve precise targeted therapy for tumors. Summary of the Invention

[0006] To address the limitations of single-metal MOFs in tumor therapy, such as weak catalytic activity of metal ions towards H2O2, limited therapeutic efficacy with single treatment modalities, and a lack of specificity in active tumor targeting, this invention provides a Fe / Mn porphyrin-based bimetallic organic framework, its preparation method, and its applications. A Fe / Mn porphyrin-based bimetallic organic framework, Fe-TCPP(Mn)(FTM), exhibiting Fenton-like catalytic activity, peroxidase-like activity, and photodynamic properties, is prepared using a one-pot solvothermal method. Furthermore, using FTM as a carrier, doxorubicin is loaded via π-π stacking, PEG is surface-modified via van der Waals physical adsorption, and aptamers capable of recognizing cell surface-specific proteins are covalently coupled to form the nanocomposite Fe-TCPP(Mn) / DOX / PEG / Apt-M (FTMDPA). This nanocomposite not only possesses excellent biosafety and tumor targeting, but also generates reactive oxygen species under 660 nm laser irradiation for photodynamic therapy. Furthermore, it enhances the efficacy of chemokinetic therapy by catalyzing a Fenton-like reaction and exerting peroxidase-like activity to convert H₂O₂ in the tumor microenvironment into •OH. In addition, the doxorubicin loaded on this nanocomposite can be released in a pH-responsive manner, enabling chemotherapy. Due to the unique fluorescence properties of doxorubicin, it can be used for in vivo fluorescence imaging. FTMDPA achieves precise and efficient tumor treatment through the combined action of photodynamic, chemokinetic, and chemotherapy modes under fluorescence imaging guidance. This invention successfully prepares a novel bimetallic organic framework material, providing a highly efficient and precise new treatment method for the field of tumor therapy, with promising clinical application prospects.

[0007] To achieve the above objectives, the present invention employs the following technical solution: This invention provides a Fe / Mn porphyrin-based bimetallic organic framework, through Fe 3+ Coordination with the carboxyl group on the TCPP ligand, Mn 2+ It is obtained by coordinating with the nitrogen atom on the TCPP ligand, and it possesses Fenton-like catalytic activity, peroxidase-like activity and photodynamic properties.

[0008] This invention also provides a method for preparing a Fe / Mn porphyrin-based bimetallic organic framework, comprising the following steps: DMF, Fe-TCPP, MnCl2·4H2O and BA were added sequentially to the reaction vessel, the mixture was stirred, the precipitate was collected by centrifugation and washed several times to obtain the Fe / Mn porphyrin-based bimetallic organic framework.

[0009] Furthermore, the mass ratio of Fe-TCPP, MnCl2·4H2O and BA is 40 mg:135 mg:1.2 g.

[0010] Furthermore, the stirring reaction was carried out at a temperature of 120°C for 12 hours.

[0011] This invention also provides an application of the Fe / Mn porphyrin-based bimetallic organic framework for constructing nanocomposites.

[0012] This invention also provides a nanocomposite with the aforementioned bimetallic organic framework as a carrier, on which an anticancer drug is loaded, and a nucleic acid aptamer capable of recognizing cell surface-specific proteins is covalently coupled to the surface. This nanocomposite exhibits excellent pH-responsive drug release performance, photodynamic properties, and chemokinetic properties; it also possesses active targeting capabilities, can specifically recognize tumor cells and accumulate in large quantities at the tumor site, and has in vivo fluorescence imaging capabilities, enabling visualized treatment of tumors.

[0013] Furthermore, the anticancer drug is doxorubicin.

[0014] This invention also provides a method for preparing a nanocomposite, comprising the following steps: Step 1: Loading doxorubicin onto the surface of the bimetallic organic framework of claim 1 through π-π stacking; Step 2: PEG is bound to the surface of the complex obtained in Step 1 by van der Waals physical adsorption. Step 3: A nucleic acid aptamer that can recognize cell surface-specific proteins is covalently coupled to the surface of the complex obtained in Step 2 via an EDC-NHS reaction to form the nanocomposite.

[0015] This invention also provides an application of a nanocomposite that can achieve active targeted photodynamic-chemokinetic-chemotherapy three-modal combined treatment of tumor cells, effectively inhibiting tumor cell growth and exhibiting good biosafety, while reducing damage to normal tissues.

[0016] Compared with the prior art, the present invention has the following advantages: (1) The novel FTM prepared by this invention has excellent chemical kinetic properties, Fe 3+ TCPP (Mn) can effectively catalyze the conversion of H2O2 to •OH, which can be used for CDT.

[0017] (2) The novel FTM prepared by this invention has excellent photodynamic properties. Under 660 nm laser irradiation, TCPP(Mn) can convert O2 into 1 O2, used in PDT.

[0018] (3) The nanocomposite FTMDPA prepared in this invention has good pH-responsive drug release performance, photodynamic performance and chemical kinetic performance.

[0019] (4) The nanocomposite FTMDPA prepared in this invention has active targeting performance. Through Apt-M functionalization modification, FTMDPA has excellent active targeting performance at both the in vitro tumor cell level and the in vivo mouse tumor tissue level. At the same time, the nucleic acid aptamer can be designed to target different target cells and different cell surface specific antigens, so it can be applied to the treatment of a variety of cancers.

[0020] (5) The nanocomposite FTMDPA prepared in this invention has in vivo fluorescence imaging capability, which can realize the visualization treatment of tumors.

[0021] (6) The nanocomposite FTMDPA prepared in this invention integrates photodynamic therapy, chemokinetics and chemotherapy to achieve a powerful combination of the three, which is an efficient, safe and visualized tumor treatment strategy. Its significant inhibitory effect on tumor cells has been verified in vitro and in vivo, further overcoming the limitations of single therapy in completely eradicating tumors.

[0022] Following tail vein injection, under the active targeting effect of Apt-M, FTMDPA specifically targets MCF-7 cells, accumulating in large quantities at the tumor site. Under 660 nm laser irradiation, TCPP(Mn) can convert O2 into... 1 O2, used in PDT. Additionally, Fe... 3+ TCPP (Mn) can catalyze the conversion of H₂O₂ to •OH, which is used for CDT. DOX is released responsively in the TME, exerting a CHT effect. Furthermore, due to its unique fluorescence properties, DOX can be used for in vivo FLI. In vivo and in vitro experimental results show that, under FLI guidance, FTMDPA exhibits excellent combined PDT-CDT-CHT antitumor effects, and can serve as a novel, multifunctional, therapeutic nanotherapy system for tumor treatment, showing broad application prospects in the biomedical field. Attached Figure Description

[0023] Figure 1 This is a schematic diagram illustrating the preparation and application of the Fe / Mn porphyrin-based bimetallic organic framework in this invention; Figure 2 The image shown is the SEM image of the FTM in Embodiment 1 of the present invention; Figure 3 The TEM image and element mapping image of FTM in Embodiment 1 of the present invention; Figure 4 The XPS analysis results of FTM in Embodiment 1 of the present invention; Figure 5 The results of ultraviolet-visible spectral analysis of TCPP, FT, and FTM in Example 1 of this invention; Figure 6The results of FT-IR spectral analysis of TCPP, FT, and FTM in Example 1 of this invention; Figure 7 The XRD analysis results of FT and FTM in Embodiment 1 of the present invention; Figure 8 The results of ultraviolet-visible spectral analysis of FTM, FTMD, FTMDP and FTMDPA in Example 1 of this invention; Figure 9 The results of FT-IR spectral analysis of FTM, FTMD, FTMDP and FTMDPA in Example 1 of this invention; Figure 10 The results of DLS analysis of FTM, FTMD, FTMDP and FTMDPA in Embodiment 1 of the present invention; Figure 11 The results of Zata potential analysis for FTM, FTMD, FTMDP, and FTMDPA in Example 1 of this invention; Figure 12 The results of pH-responsive drug release performance analysis of FTMDPA in Example 2 of this invention; Figure 13 The results of chemical kinetic performance analysis of FT, FTM and FTMDPA in Example 3 of this invention; Figure 14 The results of photodynamic performance analysis of FT, FTM, and FTMDPA in Example 4 of this invention; Figure 15 This is a comparison chart of the uptake of MCF-7 cells by different nanomaterials after incubation for different times in Example 5 of the present invention; Figure 16 The results of ROS generation analysis of MCF-7 cells under different treatments in Example 6 of this invention; Figure 17 The results show the survival rate analysis of MCF-7 cells after treatment with various nanomaterials in Example 7 of this invention; Figure 18 This is a graph showing the change in nanomaterial enrichment at the tumor site in mice after tail vein injection of FTMDPA and FTMDPC in Example 8 of the present invention over time. Figure 19 The distribution of FTMDPA and FTMDPC in the heart, liver, spleen, lung, kidney and tumor sites of mice in Example 9 of the present invention is shown. Figure 20 This is a graph showing the changes in tumor volume in mice after treatment with various nanomaterials in Example 10 of the present invention; Figure 21 This is an anatomical diagram of mouse tumors after treatment with various nanomaterials in Example 10 of the present invention; Figure 22This is a graph showing the changes in mouse body weight during treatment with various nanomaterials in Example 10 of the present invention; Figure 23 The images show H&E sections of the heart, liver, spleen, lungs, and kidneys of mice during treatment with various nanomaterials in Example 10 of this invention. Detailed Implementation

[0024] To further illustrate the technical solution of the present invention, the present invention will be further described below through embodiments. Example 1

[0025] like Figure 1 As shown, this embodiment presents a Fe / Mn porphyrin-based bimetallic organic framework, Fe-TCPP(Mn) (FTM), which utilizes Fe... 3+ Coordination with the carboxyl group on the TCPP ligand, Mn 2+ It is obtained by coordinating with the nitrogen atom on the TCPP ligand, and it possesses Fenton-like catalytic activity, peroxidase-like activity, and photodynamic properties.

[0026] The Fe / Mn porphyrin-based bimetallic organic framework was prepared as follows: 40 mg Fe-TCPP (FT), 135 mg MnCl2·4H2O, and 1.2 g BA were added to a round-bottom flask and dissolved in 30 mL DMF. The mixture was stirred at 120 °C for 12 hours, and the solution was centrifuged and washed three times with DMF to obtain FTM.

[0027] Depend on Figure 2 The SEM image shown indicates that the average length of the FTM is 180 nm and the width is 90 nm. Figure 3 The TEM and elemental mapping images shown indicate that C, N, O, Fe, and Mn are uniformly distributed in the FTM. Figure 4 The XPS analysis results shown further confirm that FTM contains C, N, O, Fe, and Mn elements. Figure 5 As shown, the FT spectrum exhibits a strong absorption peak at 425 nm and four weak peaks between 500 and 700 nm, which may be attributed to the Soret and Q bands of the TCPP ligand, respectively. Compared with the FT, the FTM spectrum shows a larger change, with the Q band disappearing, indicating that Mn... 2+ It successfully coordinated with the nitrogen atom in the porphyrin molecule. Furthermore, from... Figure 6 As shown, the FT-IR spectrum of FT is at 1650 cm⁻¹. -1 1400 cm -1 The characteristic peak of carboxylate and 965 cm⁻¹ appeared at the location. -1 The asymmetric vibrational intensity of the amino characteristic peak at this location indicates that Fe 3+It coordinates with the carboxyl group. Furthermore, NH bonds (~965 cm⁻¹) were observed in the FTM. -1 The weakening of ) and N-Mn bonds (~10¹⁰ cm⁻¹) -1 The appearance of Mn indicates that 2+ It successfully coordinated with the nitrogen atom in the porphyrin molecule. Figure 7 The XRD analysis results shown indicate that the obtained FTM has the characteristic diffraction peaks of FT, proving the successful preparation of FTM.

[0028] Because FTM has a large specific surface area, its specific surface area is as high as 386 m². 2 g -1 It can be used as a drug carrier for constructing nanocomposites. Doxorubicin (DOX) is loaded onto the surface of FTM via π-π stacking to obtain Fe-TCPP(Mn) / DOX(FTMD). COOH-PEG-COOH is bound to the FTMD surface via van der Waals physical adsorption to obtain Fe-TCPP(Mn) / DOX / PEG (FTMDP). Nucleic acid aptamers that can recognize cell surface-specific proteins are covalently coupled to the FTMDP surface via EDC-NHS reaction to form the nanocomposite Fe-TCPP(Mn) / DOX / PEG / Apt-M (FTMDPA). The specific steps include: (1) Loading DOX: Add 1 mL of FTM (1 mg / mL) to the DOX loading solution. -1 Add to 3 mL of DOX (1 mg / mL) -1 The solution was stirred overnight. The product was collected by centrifugation and washed three times with deionized water to remove unreacted DOX. The product was then vacuum dried for 8 hours to obtain FTMD, which was stored at 4°C for later use.

[0029] (2) COOH-PEG-COOH surface modification: 2 mL of FTMD dispersion (1 mg / mL) was added. -1 ) and 2 mL COOH-PEG-COOH (concentration of 10 mg / mL) -1 Mix and stir for 12 hours. Separate FTMDP by centrifugation and wash three times with deionized water to remove unreacted COOH-PEG-COOH. Vacuum dry for 8 hours to obtain the product FTMDP, and store it in a refrigerator at 4°C for later use.

[0030] (3) Coupling of Apt-M: Add 1 mL of FTMDP (2 mg / mL) to the container. -1The activated FTMDP was activated for 30 min with 500 µL EDC•HCl (500 mM) and 500 µL NHS (100 mM) under stirring. The activated FTMDP was collected by centrifugation. Simultaneously, Apt-M (10 OD) was denatured at 85°C for 10 min, followed by annealing in an ice bath for 10 min. The activated FTMDP was then reacted with Apt-M under shaking for 5 h. Finally, FTMDPA was obtained by repeated centrifugation and washing, and then washed repeatedly with deionized water for subsequent experiments. Furthermore, to verify the targeting performance of FTMDPA, Fe-TCPP(Mn) / DOX / PEG / Apt-C (FTMDPC) was prepared under the same conditions using Apt-C (without targeting ability) as a control sequence.

[0031] Depend on Figure 8 UV-Vis spectroscopy shows that FTM has an absorption peak at 420 nm. After loading DOX, FTMD shows a significant absorption peak at 480 nm. Furthermore, from... Figure 9 The FT-IR spectrum in the FTMD showed the typical characteristic peak of the aromatic ring of DOX (1730 cm⁻¹). -1 ).Depend on Figure 10 and Figure 11 As can be seen, due to the loading of DOX, the hydrated particle size of FTMD increased from 101.7 nm to 110.1 nm, and the Zeta potential decreased from 44.7 mV to 46.1 mV. These results indicate that DOX was successfully loaded into FTM.

[0032] Depend on Figure 10 and Figure 11 The results show that the hydrated particle size of FTMDP increased to 164.4 nm due to the modification of the FTMD surface with COOH-PEG-COOH, while the Zeta potential decreased to -14.9 mV. These results indicate that the FTMD surface was successfully modified with COOH-PEG-COOH.

[0033] Depend on Figure 9 The FT-IR spectrum of FTMDPA is shown to be at ~1644 cm⁻¹. -1 (Amide peak I, tensile vibration of C=O), ~1573cm -1 (Amide peak II, stretching vibration of NH) and ~1342 cm⁻¹ -1 A distinct stretching vibration was observed at (amide peak III, stretching vibration of CN). This is mainly due to the reaction of the amino group of Apt-M with COOH-PEG-COOH to form an amide bond. Furthermore, a -CH2- group belonging to Apt-M (~2894 cm⁻¹) was also observed in the FT-IR spectrum of FTMDPA. -1 Characteristic peaks and C=O (~1731 cm⁻¹) -1The tensile vibration of ). Figure 10 and Figure 11 As can be seen, due to the coupling of Apt-M with targeting properties on the surface of FTMDP, the hydrated particle size of FTMDPA increased to 208.9 nm, while the Zeta potential decreased to -20.5 mV. These results indicate that the surface of FTMDP was successfully modified and coupled with Apt-M, that is, the nanocomposite FTMDPA was successfully synthesized. Example 2

[0034] To investigate the pH-responsive drug release performance of FTMDPA, FTMDPA (1 mg) was dispersed in PBS at pH 5.0 or 7.4 and reacted at 37°C in the dark. At specific time intervals (0, 1, 2, 4, 6, 8, 10, 12, 24 hours), the supernatant was collected by centrifugation, and the absorbance of the supernatant was measured using a UV-vis spectrophotometer.

[0035] Depend on Figure 12 As can be seen, after incubation in PBS at pH 5.0 for 24 hours, the release rate of DOX reached as high as 41.93%, indicating that FTMDPA exhibits pH-responsive drug release characteristics. FTMDPA holds promise for releasing DOX within slightly acidic tumor cells, thus enabling chemotherapy (CHT). Example 3

[0036] To evaluate the chemical kinetic performance of FTMDPA, DMPO was used as a trapping agent for the detection of •OH. FT, FTM, and FTMDPA were reacted with H2O2 (10 mM) at pH 5.0 for 10 minutes, and their performance in generating •OH was tested by ESR.

[0037] FT under acidic conditions and in the presence of H2O2, Fe 3+ It can catalyze Fenton-like reactions to produce •OH. In FTM, due to the POD-like activity of TCPP(Mn), even more •OH can be produced. Figure 13 Enhanced •OH characteristic ESR signals (1:2:2:1) were observed in both the FTM and FTMDPA groups, indicating that FTM exhibits superior CDT performance compared to FT. These results suggest that FTMDPA, through its ability to effectively catalyze H2O2 production, holds promise as an effective CDT treatment modality. Example 4

[0038] To evaluate the photodynamic performance of FTMDPA, DPBF was used as the detection method. 1 O2 indicator. Add 50 µL of FTM (1 mg / mL) -1 ) and FTMDPA (1 mg mL) -1Add each to 3.0 mL of DPBF (14 µg / mL) -1 In the experiment, the mixed solution was irradiated with a 660 nm laser for 10 minutes, and the UV-vis absorption spectrum was detected every two minutes.

[0039] Depend on Figure 14 As can be seen, under 660 nm laser irradiation, the absorbance value of FTM gradually decreases, indicating that FTM has excellent absorbance. 1 O2 generation capacity. Furthermore, under the same conditions, the absorbance value of FTMDPA gradually decreased, indicating that FTMDPA also possesses excellent O2 generation capacity. 1 O2 generation performance. Therefore, FTMDPA has good PDT performance and can be used for tumor PDT. Example 5

[0040] To verify the targeting performance of Apt-M, a competitive experiment was designed. MCF-7 cells were seeded in 12-well plates and cultured for 24 hours. A mixture containing FTMDP (100 µg / mL) was used. -1 ), FTMDPA (100 µg mL) -1 ), FTMDPA (100 µg mL) -1 +2OD Apt-C and FTMDPA (100 µg mL) -1 The original culture medium was replaced with 2OD Apt-M medium, and the co-incubated MCF-7 cells were then analyzed by flow cytometry.

[0041] Depend on Figure 15 It is evident that Apt-M targets the MUC1 protein on the surface of MCF-7 cells, thus increasing the uptake of FTMDPA by MCF-7 cells. Furthermore, the significant decrease in fluorescence signal after co-incubation of MCF-7 cells with Apt-M followed by FTMDPA indicates that Apt-M can shield the MUC1 protein site on the MCF-7 cell surface, leading to a sharp reduction in the amount of FTMDPA entering the MCF-7 cells and preventing FTMDPA from exerting its targeting effect. These results demonstrate that FTMDPA can effectively target MCF-7 cells. Example 6

[0042] The DCFH-DA indicator was used to assess ROS production performance in cells. MCF-7 cells were seeded into confocal culture dishes and cultured for 24 hours. The MCF-7 cells in the confocal culture dishes were then treated with different nanomaterials for 4 hours. Next, before irradiation with a 660 nm laser, the MCF-7 cells were stained with the DCFH-DA probe for 30 minutes. Finally, the cells were washed several times with PBS and observed using CLSM.

[0043] Depend on Figure 16 As can be seen, the fluorescence of the FT and FTM groups was weak, indicating that a small amount of •OH was generated intracellularly. After 660 nm laser irradiation, the fluorescence intensity increased, indicating that more ROS were generated under CDT and PDT. The fluorescence intensity was highest under targeted conditions, further indicating that more FTMDPA entered MCF-7 cells and generated a large amount of ROS. These results demonstrate that FTMDPA can effectively generate ROS in MCF-7 cells and holds promise for use in CDT and PDT for tumors. Example 7

[0044] MCF-7 cells were seeded in 96-well plates and cultured for 24 hours. The original culture medium was discarded, and fresh culture medium containing each nanomaterial was added, followed by 4 hours of further culture. Subsequently, the cells were slowly washed with PBS. All laser treatment groups used a power intensity of 400 mW cm⁻¹. -2 Cells were irradiated with a 660 nm laser for 10 minutes. After culturing for 12 hours, cell viability was assessed using the MTT assay.

[0045] Depend on Figure 17 As can be seen, because FTM can perform combined CDT and PDT therapy on tumor cells, the survival rate of MCF-7 cells under laser irradiation was 51.1%, while the survival rate of MCF-7 cells in the FTM group without laser irradiation was 73.7%. When FTMDP was irradiated with a 660 nm laser, the survival rate of MCF-7 cells decreased to 43.7%, demonstrating a good combined PDT-CDT-CHT therapeutic effect on tumors. Meanwhile, with the help of Apt-M's excellent active targeting capability, the survival rate of MCF-7 cells after PDT-CDT-CHT targeting in the FTMDPA + L group was only 34.3%. These results indicate that FTMDPA can achieve active targeting of tumor cells to PDT-CDT-CHT. Example 8

[0046] To evaluate the accumulation efficiency of FTMDPA in mouse tumor tissues, the biological distribution of FTMDPA was analyzed based on in vivo fluorescence imaging. A unilateral tumor-bearing nude mouse model was established by subcutaneous injection of MCF-7 cells into the right groin of mice. The tumor volume was measured when it reached ~300 mm². 3 Subsequently, each mouse was intravenously injected with FTMDPA (2 mg / mL). -1 ) or FTMDPC (2 mg mL) -1 In vivo fluorescence imaging was performed at fixed time points after injection.

[0047] Depend on Figure 18As can be seen, compared with FTMDPC, after intravenous injection of FTMDPA, the fluorescence intensity of mouse tumors gradually increased and reached a peak at 8 hours, indicating that FTMDPA also has excellent targeting ability in mice. Example 9

[0048] To investigate the biodistribution of FTMDPA in vivo, all mice were euthanized 8 hours after tail vein injection of FTMDPA, and major organs (heart, lungs, liver, spleen, and kidneys) and tumors were collected for further fluorescence analysis.

[0049] Depend on Figure 19 As can be seen, the fluorescence signal was strongest at the tumor site, further demonstrating the targeting ability of Apt-M. Furthermore, significant fluorescence was also observed in the liver and kidneys, indicating that FTMDPA is primarily metabolized by these organs. These results demonstrate that FTMDPA can effectively accumulate at the tumor site and be excreted through the liver and kidneys. Example 10

[0050] A nude mouse tumor model was established using MCF-7 cells. 100 µL of MCF-7 cells suspended in PBS solution were injected subcutaneously into mice. When the tumor volume reached approximately 100 mm²... 3 Mice were randomly divided into five groups (n=5 per group): (1) control group (PBS), (2) FTM (2 mg / mL) -1 ), (3) FTM + L (2 mg mL -1 ), (4) FTMDP + L (2 mg mL -1 ), (5) FTMDPA+ L (2 mg mL -1 Eight hours after tail vein injection, the tumor sites of mice in the laser-treated group were treated with a 660 nm laser (500 mW / cm²). -2 Irradiate for 5 minutes.

[0051] Depend on Figure 20 and Figure 21 As can be seen, both the FTM and FTM+L groups showed limited tumor growth inhibition, indicating that CDT or PDT-CDT combined therapy could only slightly inhibit tumor growth in mice. However, the FTMDP+L group showed a more significant tumor inhibition effect in mice, indicating that the PDT-CDT-CHT combined therapy strategy could inhibit tumor growth in mice. Finally, the FTMDPA+L group showed a significant tumor inhibition effect, and two mice were completely cured. This indicates that the active targeted PDT-CDT-CHT combined therapy had the best tumor inhibition effect.

[0052] During tumor treatment in mice, the mice's body weight was recorded every two days. Figure 22 As can be seen, the weight gain of mice in all groups was stable, and there was no significant difference in weight gain between groups, indicating that FTMDPA has good biocompatibility. After 14 days of treatment, mice were euthanized, and tissues from major organs (heart, lungs, liver, spleen, and kidneys) were harvested. H&E staining was used to assess whether these nanomaterials caused damage to the major organ tissues of the mice during treatment. Figure 23 As can be seen, H&E staining results of the heart, liver, spleen, lungs, and kidneys showed no significant pathological changes in mice in each treatment group after treatment, indicating that FTMDPA is relatively safe. In summary, these results demonstrate that FTMDPA, as a safe, efficient nanomaterial integrating fluorescence imaging capabilities, has enormous application potential in the biomedical field.

[0053] The sequences of Apt-M and Apt-C in the above embodiments are as follows: The Apt-M sequence is: NH2-(CH2)6-GCAGTTGATCCTTTGGATACCCTGGGTTTTTTTTTT; The Apt-C sequence is: NH2-(CH2)6-ATTGCACTTACTATATTGCACTTACTATATTGCAC.

[0054] The foregoing has shown and described the main features and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0055] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A Fe / Mn porphyrin-based bimetallic organic framework, characterized in that, Through Fe 3+ Coordination with the carboxyl group on the TCPP ligand, Mn 2+ It is obtained by coordinating with the nitrogen atom on the TCPP ligand, and it possesses Fenton-like catalytic activity, peroxidase-like activity and photodynamic properties.

2. A method for preparing the Fe / Mn porphyrin-based bimetallic organic framework according to claim 1, characterized in that, Includes the following steps: DMF, Fe-TCPP, MnCl2·4H2O and BA were added sequentially to the reaction vessel, the mixture was stirred, the precipitate was collected by centrifugation and washed several times to obtain the Fe / Mn porphyrin-based bimetallic organic framework.

3. The method for preparing a Fe / Mn porphyrin-based bimetallic organic framework according to claim 2, characterized in that, The mass ratio of Fe-TCPP, MnCl2·4H2O and BA is 40 mg:135 mg:1.2 g.

4. The method for preparing a Fe / Mn porphyrin-based bimetallic organic framework according to claim 2, characterized in that, The stirring reaction was carried out at a temperature of 120°C for 12 hours.

5. An application of the Fe / Mn porphyrin-based bimetallic organic framework according to claim 1, characterized in that, Used to construct nanocomposites.

6. A nanocomposite, characterized in that, Using the bimetallic organic framework described in claim 1 as a carrier, an anticancer drug is loaded on the surface, and a nucleic acid aptamer that can recognize cell surface specific proteins is covalently coupled to the surface.

7. A nanocomposite according to claim 6, characterized in that, The anticancer drug mentioned is doxorubicin.

8. A method for preparing the nanocomposite according to claim 6 or 7, characterized in that, Includes the following steps: Step 1: Loading doxorubicin onto the surface of the bimetallic organic framework of claim 1 through π-π stacking; Step 2: PEG is bound to the surface of the complex obtained in Step 1 by van der Waals physical adsorption. Step 3: A nucleic acid aptamer that can recognize cell surface-specific proteins is covalently coupled to the surface of the complex obtained in Step 2 via an EDC-NHS reaction to form the nanocomposite.

9. An application of the nanocomposite according to claim 6 or 7, characterized in that, This is used to prepare drugs for the combined photodynamic-chemokinetic-chemotherapy three-modal treatment of tumor cells with active targeting.

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