Manganese-based organic frameworks and methods of making the same, methods of drug delivery

Abstract

The application provides a manganese-based organic framework and a preparation method and a drug delivery method thereof, wherein the manganese-based organic framework is generated through coordination connection of metal manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl) ethylene ligands, the structure of the manganese-based organic framework is Mn2(TCPE)(H2O), wherein the TCPE is a fluorescent probe 1,1,2,2,-tetra(4-carboxyphenyl) ethylene. The manganese-based organic framework can be used as a nano-carrier with high drug loading capacity, can load active drug molecules with small and medium sizes, and can be used for treating cardiovascular diseases, cancers, microbial infections, wound healing, diabetes, senile dementia, tuberculosis and the like, and has no label and intrinsic fluorescence capacity, and can play a crucial role in actual experiments and interventions for detecting nano-carriers and rapidly tracking drugs.

Description

Technical Field

[0001] This application relates to the field of drug delivery, and in particular to a manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene, its preparation method, and drug delivery method. Background Technology

[0002] According to the World Health Organization (WHO), cardiovascular disease (CVD) causes nearly 18 million deaths annually, making it one of the leading causes of death worldwide, with approximately 22 million deaths each year. These diseases incur over $860 billion in costs annually, an economic loss unmatched by any other disease. In light of this, researchers have been dedicated to developing new technologies to enhance the effectiveness of existing treatments. Statins, antiplatelet drugs, anticoagulants, antiarrhythmic drugs, and antihypertensive drugs are common medications for CVD, and their effectiveness has been widely proven. However, after taking these medications, patients may experience adverse reactions ranging from muscle pain, fatigue, and nausea to dangerous arrhythmias, kidney damage, and bleeding.

[0003] Fortunately, drug delivery is a mature and powerful technology that effectively addresses the aforementioned shortcomings. By delivering therapeutic molecules to specific sites, it allows for targeted drug delivery, thereby improving efficacy and reducing drug-related side effects. Nanomaterials such as liposomes, polymers, quantum dots, and gold nanoparticles have been widely used to deliver therapeutic compounds for the treatment of cardiovascular diseases. However, drug delivery often hinders the drug development process due to the lack of precise targeting to the administration site. Currently, fluorescence microscopy is widely used to accurately observe drug delivery in the cardiovascular system, identifying areas of low drug delivery efficiency and exploring potential solutions to improve the situation. Therefore, fluorescent nanocarriers are of great significance in studying the dynamic changes of drug release and monitoring adverse reactions.

[0004] However, most existing fluorescence monitoring technologies utilize commercially available fluorescent dyes (such as rhodamine, Cy5, FITC, etc.) to immobilize nanocarriers, which then emit light signals upon excitation by an external radiation source, thereby enabling the monitoring of the nanocarrier's position and structure. However, fluorescent dye labeling is expensive and time-consuming; furthermore, this process may compromise the stability, effectiveness, and selectivity of the nanocarrier. More frequently, incorrect labeling or probe leakage from porous nanocarriers can lead to inaccurate or erroneous results. Summary of the Invention

[0005] The main objective of this application is to provide a label-free, stable, fluorescent manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene with synergistic multifunctionality. It possesses the properties of a coordination polymer, has a high surface area to volume ratio, and exhibits good drug loading capacity, stability, and compatibility.

[0006] Another objective of this application is to provide a method for preparing the above-mentioned manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene.

[0007] Another objective of this application is to provide a drug delivery method that uses the aforementioned manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene as the delivery material.

[0008] To achieve the above objectives, this application provides the following technical solution:

[0009] As a first aspect, this application relates to a manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene, wherein the structure of the manganese-based organic framework is Mn2(TCPE)(H2O), wherein the TCPE is a fluorescent probe 1,1,2,2,-tetra(4-carboxyphenyl)ethylene.

[0010] Further configuration: The manganese-based organic framework has a nanoscale size between 200 and 10 μm.

[0011] Further configuration: Drugs can be loaded within the pores of the manganese-based organic framework, on the inner and outer surfaces of the nanoparticles, and between the aggregates. This allows for application in coagulants, anticoagulants, antiplatelet agents, anti-inflammatory drugs, gases, anticancer drugs, and other medications. The gases include, but are not limited to, nitric oxide, hydrogen, hydrogen sulfide, and carbon monoxide.

[0012] Further configuration: for use in contact with a target via a patch, implant, bandage, stent, catheter or other implantable or non-implantable device for delivery, treatment and / or diagnosis.

[0013] As a second aspect, this application relates to a method for preparing a manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene as described above, comprising the following steps:

[0014] 1) Add the manganese precursor to an appropriate amount of solvent;

[0015] 2) Dilute 1,1,2,2,-tetra(4-carboxyphenyl)ethylene with an appropriate amount of distilled water, or add 1,1,2,2,-tetra(4-carboxyphenyl)ethylene to distilled water containing dimethylformamide to obtain a ligand solution;

[0016] 3) Deprotonate the ligand solution;

[0017] 4) The deprotonated ligand solution from step 3) was gradually added to the manganese precursor solution at a constant rate, and the mixed solution was divided into multiple experimental groups according to different temperatures and stirred.

[0018] 5) After the mixed solution in step 4) has been stirred for the set time, let it stand in the dark, and wash and centrifuge the lower precipitate multiple times to obtain the manganese-based organic framework. Dry the obtained manganese-based organic framework in a vacuum oven.

[0019] Further configuration: Step 3) deprotonating the ligand solution includes adding potassium hydroxide or sodium hydroxide to the ligand solution for deprotonation.

[0020] Further setting: The ratio of the deprotonated solution to the ligand solution is in the range of 1:2 to 1:4.

[0021] Further configuration: the solvent content in the ligand solution does not exceed 1 / 4, and the solvent is distilled water or distilled water with added dimethylformamide.

[0022] Further setting: The stirring temperature range in step 4) is 25℃ to 60℃.

[0023] Further setting: The stirring time in step 4) is 8h-5d.

[0024] As a third aspect, this application relates to a drug delivery method that uses a manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene as the drug delivery material, or uses a substance obtained by the preparation method of the manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene as the drug delivery material.

[0025] Further configuration: The drug delivery method includes a drug loading process and a drug release process;

[0026] The drug loading process includes the following steps: suspending the target drug in an aqueous solution, adding the drug delivery material to the aqueous solution containing the target drug according to a set ratio, continuously stirring the resulting suspension for 48 hours, and centrifuging the suspension multiple times until its supernatant becomes clear.

[0027] The drug release process includes the following steps: suspending the drug delivery material loaded with the target drug in an aqueous solution, injecting it into different dialyzers using a pipette, immersing the dialyzers in containers containing phosphate buffer solutions with different pH values, and then keeping the containers in a shaker at a constant speed and at a preset temperature.

[0028] Further setting: The formula for calculating the drug loading capacity of the drug delivery material is: LC% = (M T -M uT ) / (M T -M uT +M C )*100;

[0029] The formula for calculating the drug loading efficiency of the drug delivery material is: LE% = (M T -M uT ) / M uT *100;

[0030] Among them, M T M uT and M C These are the total amount of target drug used in the formulation, the amount of unloaded target drug, and the amount of drug delivery material used, respectively.

[0031] Compared with existing technologies, the solution in this application has the following advantages:

[0032] 1. The manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene involved in this application is generated through coordination linking of metallic manganese ions and TCPE ligands, providing a fully extended three-dimensional cavity network and a well-developed porous structure. This enables the manganese-based organic framework of this application to serve as a nanocarrier with high drug loading capacity, which can load small and medium-sized active drug molecules for the treatment of cardiovascular diseases, cancer, microbial infections, wound healing, diabetes, Alzheimer's disease, tuberculosis, etc.

[0033] 2. The manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene involved in this application has tagless and inherent fluorescence capabilities, which can play a crucial role in practical experiments and interventions for detecting nanocarriers and rapidly tracking drugs. Furthermore, the photophysical properties of the manganese-based organic framework in this application are inherited by its bridging ligand TCPE, which makes the manganese-based organic framework in this application have good stability.

[0034] 3. The manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene involved in this application exhibits pH-triggered release in slightly alkaline media, and can significantly inhibit drug release even in highly corrosive acidic media.

[0035] 4. In the preparation method of manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene involved in this application, the manufacturing process is optimized, the energy consumption of the preparation process is minimized, the operation is simple, the aqueous solution is used to avoid toxicity and pore contamination, and any additional costs that may be caused by toxicity and commonly used solvents can be eliminated, which is conducive to realizing mass production.

[0036] 5. The manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene involved in this application can encapsulate different active drug molecules and release them upon stimulation, while providing a multifunctional imaging mode for monitoring and diagnosis. The manganese-based organic framework of this application can induce emission in the polymerized state for photodynamic or thermodynamic therapy of cardiovascular diseases and other diseases.

[0037] Additional aspects and advantages of this application will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of this application. Attached Figure Description

[0038] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0039] Figure 1 X-ray diffraction patterns of three synthesized metal-organic frameworks (CCH-1, 2, and 3) collected from 7° to 80°;

[0040] Figure 2 For metal-organic frameworks (CCH-2 and TCPE) in the range of 400 to 3600 cm⁻¹ -1 Fourier transform infrared spectrum within the range;

[0041] Figure 3 Scanning electron microscope photographs of CCH-1 (scale bar = 1µm);

[0042] Figure 4 The UV-Vis absorption spectra of CCH-1, CCH-2, and CCH-3 are shown.

[0043] Figure 5 The photoluminescence spectra of CCH-2 and TCPE are shown, with the emission wavelength at 320 nm.

[0044] Figure 6 The images show microscopic images of CCH-3 in DMEM under (A) bright field, (B) 550 nm excitation, (C) 385 nm excitation and (D) 475 nm excitation, respectively.

[0045] Figure 7 UV-Vis spectra for blood compatibility analysis of CCH;

[0046] Figure 8 This is a schematic diagram illustrating the cell viability assay for lung fibroblasts.

[0047] Figure 9 The cumulative tetracycline release curves of CCH-2 nanocarriers at pH 7.4 and 5.5 in PBS are shown.

[0048] Figure 10 This is a fitting model for the cumulative tetracycline release data. Detailed Implementation

[0049] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0050] To address the medication challenges in acute cardiovascular diseases, this application provides a manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene. By using this manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene as a basic nanocarrier, it can simultaneously provide functions such as efficient drug loading, controlled release, and photoluminescence within a specific range.

[0051] Specifically, the chemical structure of the manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene in this application is Mn2(TCPE)(H2O), wherein the TCPE serves as a bridging ligand, specifically the fluorescent probe 1,1,2,2,-tetra(4-carboxyphenyl)ethylene. This manganese-based organic framework can serve as a tagless fluorescent MOF nanocarrier, possessing a nanoscale size, good biocompatibility, and controllable drug release capability. Furthermore, it can provide efficient and simultaneous combined interventions, enabling real-time drug tracking in vivo and achieving powerful, controllable drug delivery.

[0052] The aforementioned manganese-based organic framework based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene can be obtained through the following preparation method, which includes the following steps:

[0053] 1) Add the manganese precursor to an appropriate amount of solvent. Specifically, in this embodiment, manganese chloride tetrahydrate is added to deionized water and stirred until the metal salt is clearly dissolved.

[0054] 2) 1,1,2,2,-tetra(4-carboxyphenyl)ethylene (i.e., fluorescent probe 1,1,2,2,-tetra(4-carboxyphenyl)ethylene, hereinafter referred to as "TCPE") is also added to an appropriate amount of distilled water for dilution, or TCPE is added to distilled water with added dimethylformamide to obtain a ligand solution. That is, the ligand solution uses distilled water or distilled water with added dimethylformamide as the solvent for TCPE, and the solvent content in the ligand solution does not exceed 1 / 4 of the total solution volume.

[0055] 3) The ligand solution is deprotonated. Deprotonation is the process of removing a proton (H) from a molecule to produce its conjugate base. In this embodiment, the pH value of the ligand solution is adjusted by adding an appropriate amount of potassium hydroxide or sodium hydroxide to achieve deprotonation. Further preferably, the ratio of the alkaline solution used for deprotonation to the ligand solution in this embodiment is in the range of 1:2 to 1:4.

[0056] 4) The deprotonated ligand solution from step 3) is added to the manganese precursor solution in a controlled manner. Different temperatures within a set temperature range are selected to stir the mixture to obtain different syntheses. The deprotonated ligand solution is gradually added to the prepared manganese precursor solution from step 1) in a controlled manner, i.e., at a constant rate. The temperature range of this application is 25°C to 60°C. Therefore, this application sets up three experimental groups to stir the mixture at room temperature (25°C), 40°C, and 60°C, respectively.

[0057] 5) After the mixed solution in step 4) has been stirred for the set time, it is allowed to stand in the dark. The lower precipitate is washed and centrifuged multiple times to obtain the manganese-based organic framework compound. The obtained manganese-based organic framework is then dried in a vacuum oven. In this embodiment, the preset stirring time is 24 hours to 5 days. Subsequently, the stirred mixed solution is placed at room temperature in the dark, and the supernatant is taken out and stored for subsequent experimental analysis. The particles obtained by washing and centrifuging the lower precipitate multiple times are dried under vacuum at 60-80°C for 12-16 hours to obtain the manganese-based organic framework CCH required by this application.

[0058] Therefore, the manganese-based organic framework (CCH) of this application was synthesized by mixing TCPE ligands with manganese ions in an aqueous solution, and the carboxylic acid groups on the TCPE ligands were deprotonated using an alkaline addition method. Furthermore, three experimental groups of this application were used to prepare CCH-1, CCH-2, and CCH-3 according to different stirring temperatures. The CCHs prepared in this application have nanoscale sizes between 200 and 10 μm. The following sections will analyze the CCHs prepared in this application from several aspects, including their structural and morphological characteristics, photophysical properties, biocompatibility, and drug loading and release.

[0059] Structural and morphological characteristics of CCH

[0060] This application uses X-ray diffraction (XRD) to analyze the structure and morphological characteristics of the obtained manganese-based organic framework (CCH). Please refer to [link to relevant documentation]. Figure 1 , Figure 1 X-ray diffraction patterns of three synthesized manganese-based organic frameworks, CCH-1, CCH-2, and CCH-3, were collected from 7° to 80°. Specifically, X-ray diffraction was collected using a Bruker D2PHASER X-ray diffractometer in θ-θ configuration with a scan step of 0.03 s. A coupling tension / current of 15 kV / 40 mA was applied to the copper anode, and X-ray diffraction was collected in the range of 7° to 80°. Figure 1 As can be seen, the three manganese-based organic frameworks CCH-1, CCH-2, and CCH-3 all exhibit X-ray diffraction at 2θ = 8.07°, 10.07°, 10.62°, 12.88°, 14.27°, 15.72°, 16.56°, 17.77°, 18.90°, 19.32°, 21.14°, 21.95°, 24.69°, 25.71°, 27.24°, 29.50°, 32.07°, and 34.23°. The well-defined dense peaks indicate that the CCH powder synthesized in this application belongs to highly crystalline metal-organic frameworks (MOFs). Furthermore, using the Scherrer formula, D = (0.94 * λ) / (β * Cos(θ)), where D is the average grain size, β is the linewidth (radians), θ is the Bragg angle, and λ is the X-ray wavelength of 0.154056 nm. CCH-2 exhibits a relatively small average grain size, only about 39 nm. Smaller crystal sizes indicate higher porosity and surface area in nanomaterials. The gaps between grains create abundant micropores, giving it a three-dimensionally expanded porous structure and a high drug loading capacity.

[0061] To further verify that the compounds prepared using the method described in this application are manganese-based organic frameworks, the Fourier transform infrared (FTIR) and attenuated total reflectance (ATR) spectra of the MOFs were measured on a Thermo Scientific Nicolet iS5 spectrometer with a spectral resolution of 4 cm⁻¹. -1 See details Figure 2 , Figure 2 For metal-organic frameworks (CCH-2 and TCPE) in the range of 400 to 3600 cm⁻¹ -1 Fourier transform infrared spectra within the range, Figure 2 The CCH of this application, in powder form, has an absorption peak at 3395 cm⁻¹. -1 1664cm -1 1586cm -1 and 1536cm-1 1398cm -1 1181cm -1 1104cm -1 1018cm -1 and 891cm -1 770cm -1 720cm -1 645cm -1 and 514cm -1 The absorption peaks of CCH-2 and TCPE in the wavelength region of 600-1700 nm characterize the typical vibrational bands of carboxyl (-COO-) and carbonyl (-C=O) groups, with a peak at 1398 cm⁻¹. -1 and 1664cm -1 The absorption peak originates from -C=C- and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene. Typically, pure TCPE will show an absorption peak at 1682 cm⁻¹. -1 The peak value for -CO is shown at 1598 cm⁻¹, but this peak is not observed in the CCH-2 curve, confirming the presence of free ligand molecules. Furthermore, -CO is stretched to 1598 cm⁻¹. -1 The transformation confirms the formation of the manganese-based organic framework CCH-2. (1664 cm) -1 and 1018cm -1 The peak values ​​were assigned to the CH bending vibrations of the benzene ring and the vibrations of the carboxylate group, respectively; conversely, 514 cm⁻¹... -1 The low-band amplitude can be attributed to the metal-oxygen bond between the oxygen from the carboxyl group and the metal, further confirming the successful formation of the manganese-based organic framework CCH-2.

[0062] In addition, a scanning electron microscope (FEI Quanta 250 Environmenta) can be used to observe the shape and size of the synthesized manganese-based organic framework. Figure 3 The scanning electron microscope image of CCH-1 (scale bar = 1 μm) shows that CCH-1 synthesized with deionized water at room temperature has a clear, crystalline polyhedral morphology with a size between 400 nm and 800 nm, which is within the size range of CCH prepared in this application.

[0063] Photophysical properties of CCH

[0064] To investigate the photophysical properties of the synthesized manganese-based organic framework (CCH), this application studied its ultraviolet absorptivity and photoluminescence using ultraviolet-visible and fluorescence spectroscopy. The ultraviolet-visible absorption spectra were measured using an Agilent CARY 3500 multi-chamber ultraviolet-visible spectrophotometer. Figure 4The UV-Vis absorption spectra of CCH-1, CCH-2, and CCH-3 show that the absorption range of CCH extends from 200 nm to 400 nm along the UV spectrum. The metal-organic framework exhibits an absorption band at 295 nm and 334 nm, with a maximum absorption peak at 251 nm. These absorption wavelengths are inherited from TCPE, which further confirms the successful synthesis of CCH organometallic compounds and that the molecular structure of the coordinating ligands remains unchanged.

[0065] This application evaluates the photoluminescence of CCH-2 and TCPE. The steady-state photoluminescence (PL) spectra were measured using a PerkinElmer LS55 spectrophotometer, and the measurement results are visible in the image. Figure 5 , Figure 5 The photoluminescence spectra of CCH-2 and TCPE are shown. Figure 5 As can be seen, CCH-2 exhibits photoluminescence in the range of 350nm to 750nm, and reaches a maximum at 460nm, which is the same emission wavelength as TCPE used in this application. That is, the manganese-based metal framework prepared in this application inherits the photoluminescence ability of its bridging ligand.

[0066] Furthermore, the TCPE used in this application is an aggregation-induced emission (AIE) active molecule. If the intramolecular motion without radiation is restricted by aggregation, it will exhibit strong luminescence relaxation after irradiation. Subsequently, CCH confines the TCPE ligands in the crystal lattice, thereby suppressing their dynamic rotation of benzene rings in the solid state, thus endowing the CCH crystals with inherent high fluorescence. Figure 6 (A), (B), (C), and (D) show that the manganese-based organic framework (CCH) can be clearly seen aggregated in DMEM medium under bright field, 550 nm, 385 nm, and 475 nm excitation wavelengths, respectively.

[0067] CCH biocompatibility

[0068] To verify the biocompatibility of the manganese-based organic framework (CCH) of this application, a hemolysis experiment was conducted. Specifically, rat blood diluted 20-fold with 0.067M phosphate buffer (pH 7.4) was incubated with CCH and either phosphate buffer (negative control) or deionized water (positive control) at 150 rpm and 37°C for 6 hours. The absorbance of the supernatant at 541 nm was then measured to test hemolysis as the CCH concentration increased. The percentage of hemolysis was calculated as follows: HI = (A... sample -A neg / A pos -A neg*100, where HI is the hemolysis index, Asample is the absorbance of CCH at a specific concentration, Aneg is the absorbance of the negative control, and Apos is the absorbance of the positive control. Please refer to the test results. Figure 7 , Figure 7 The UV-Vis spectra of CCH for blood compatibility analysis show that the UV-Vis spectra of all concentrations are close to the negative control and significantly lower than the positive control spectra. This indicates that the amount of free hemoglobin released in the blood samples is significantly lower, as their characteristic absorption at 541 nm is very weak, which demonstrates the blood compatibility of the CCH of this application. Furthermore, the hemolysis index has been calculated, showing a maximum concentration of 4.8% for CCH (200 μg / mL).

[0069] In addition, the in vitro cytotoxicity of CCH was investigated by measuring the survival rate of lung fibroblasts cultured with five different concentrations (20, 40, 60, 80, and 100 μg / ml) of CCH-2 for 24 hours. Cell viability was assessed by fluorescent staining. Hoechst (Invitrogen, #H1399, USA) and Propidium Iodide were diluted 1:1000 in an appropriate amount of PBS and incubated at 37°C for 20 minutes and 5 minutes, respectively, before adding lung fibroblasts, followed by three PBS washes. The lung fibroblasts used in this application were cultured in DMEM (Gibco, USA) supplemented with 10% (v / v) fetal bovine serum (Gibco, USA) and humidified at 37°C and 5% CO2. The lung fibroblasts were then cultured in sterile T25 flasks (Jet BIOFIL, China) and passaged after reaching 80% cell maturity. The growth medium was changed every 48-72 hours, and cells were seeded in 96- or 6-well plates (BIOFIL, China) for experiments. Cells were then imaged using a fluorescence microscope, and the images were analyzed using ImageJ software. For details, please refer to [link / reference needed]. Figure 8 , Figure 8 Cell viability assays of CCH in lung fibroblasts were performed, with data representing the average of three experiments. It can be seen that even at a relatively high concentration (100 μg / ml), CCH-2 did not exhibit significant toxicity. Therefore, it can be concluded that the CCH nanocarrier possesses excellent biocompatibility and is an ideal choice for biological applications.

[0070] Drug loading and release

[0071] The manganese-based organic framework of this application has a high surface area to volume ratio and can provide tagless intrinsic fluorescence, enabling efficient and synchronous combined intervention, allowing drugs to be tracked in vivo in real time, thereby achieving a powerful and reliable drug delivery capability. Therefore, this application also relates to a drug delivery method that uses the manganese-based organic framework of this application based on manganese ions and 1,1,2,2,-tetra(4-carboxyphenyl)ethylene as the drug delivery material.

[0072] Specifically, the drug delivery method includes a drug loading process and a drug release process. The drug loading process includes the following steps: suspending the target drug in an aqueous solution; adding the drug delivery material to the aqueous solution containing the target drug at a predetermined ratio; continuously stirring the resulting suspension for 48 hours; and centrifuging the suspension multiple times until the supernatant becomes clear. The drug release process includes the following steps: suspending the drug delivery material loaded with the target drug in an aqueous solution; injecting it into different dialyzers using a pipette; immersing the dialyzers in containers containing phosphate buffer solutions of different pH values; and then maintaining the containers in a shaker at a constant speed and at a preset temperature.

[0073] This embodiment demonstrates the loading and release of a drug model on a CCH-2 nanocarrier, using tetracycline as the target drug for loading.

[0074] First, the drug loading process involved suspending tetracycline (2 mg) in 1 ml of aqueous solution. CCH-2 was then added to the container at a mass ratio of 2:1 to the drug. The resulting suspension was continuously stirred for 48 hours. The suspension was then centrifuged multiple times until the supernatant became clear and no longer had the yellow color of the drug. The tetracycline-loaded CCH (Tetracyline@CCH-2) was recovered and stored for subsequent release experiments. Further analysis of the supernatant was performed using UV-Vis light to obtain loading parameters.

[0075] Drug loading capacity (LC%) and loading efficiency (LE%) can be calculated using the following formulas:

[0076] LC% = (M T -M uT ) / (M T -M uT +M C )*100;

[0077] LE% = (M T -M uT ) / M uT *100.

[0078] Among them, M T M uT and MC These represent the total amount of tetracycline used in the formulation, the amount of unloaded tetracycline, and the amount of CCH-2 used, respectively.

[0079] Based on the above formula, the LC% is calculated to be 14.46%, indicating a high drug loading capacity, equivalent to 0.16 mg of drug per mg of CCH-2. Under the current loading experimental conditions, the loading efficiency reaches LE% = 8.45%. Furthermore, the calculated formula allows for optimization of CCH-2 drug loading by considering the ratio of CCH-2 to the drug model, drug loading time, and the concentration of the drug model. It should also be noted that the drug models in this application include, but are not limited to, coagulants (tPA, uKA, Streptokinase, Streptase, Activase, etc.), anticoagulants (Dabigatran, Apixaban, Rivaroxaban, Heparin, Warfarin, etc.), antiplatelet agents (aspirin, cilostazol, atropasal, tirofiban, etc.), anti-inflammatory drugs, gases (NO, H2, H2S, CO, etc.), anticancer drugs (doxorubicin, etc.), and other drugs.

[0080] The drug release in this application involves suspending the loaded Tetracyline@CCH-2 in 1 ml of water and injecting it into two different dialyzers using a pipette. The two dialyzers are then immersed in containers containing 20 ml of PBS buffer at different pH values ​​(7.4, 5.5), respectively. These containers are kept in a shaker at 37 idC and 100 rpm. This application constructs release curves by sampling the supernatant within a specific time range and replacing the same volume of supernatant with fresh release medium. All extracted supernatants are preserved for further analysis using UV-Vis light to determine the cumulative concentration of released tetracycline. The specific method is as follows: Cumulative drug release = Ct * v, where Ct is the measured tetracycline concentration at sampling time t, and v is the volume of the derived sample.

[0081] This application utilizes the dialysis bag method to evaluate samples taken continuously over increasingly longer time intervals, specifically as follows: Figure 9 and Figure 10 As shown, Figure 9 The cumulative tetracycline release curves of the CCH-2 nanocarrier at pH 7.4 and 5.5 in PBS are shown. Figure 10This is a fitted model diagram of the cumulative tetracycline release data from the CCH-2 nanocarrier. Tetracyline@CCH-2 exhibited significantly different release rates under two pH conditions; within the 48-hour testing period, the release rate at pH 7.4 was faster than at pH 5.5. Furthermore, after the first 20 hours, the cumulative tetracycline release reached 25 μg at pH 7.4 and 5.75 μg at pH 5.5. This expected slower release rate at lower pH values ​​is due to the inherent fragility of manganese ions, causing them to dissociate from their coordination bonds with carboxylate ions and revert to their original state. The release data points of Tetracyline@CCH-2 best fit the first-order kinetic release equation, indicating that the drug-loaded particles have a good sustained release effect, which may be related to the fact that the loading within the pores of the CCH-2 nanoparticles is greater than the loading on the outer surface.

[0082] In summary, this application prepared a label-free, stable fluorescent manganese-based organic framework nanoparticle (CCH) through coordination linking of manganese ions and TCPE ligands, providing a fully expanded three-dimensional cavity network and a well-developed porous structure. Due to its nanoscale size, CCH can load drugs within its pores, on the inner and outer surfaces of nanoparticles, and between aggregates. CCH exhibits excellent drug loading capacity, stability, and biocompatibility. By loading small- to medium-sized active drug molecules, it can play a certain therapeutic role in areas such as cardiovascular diseases, cancer, microbial infections, wound healing, diabetes, Alzheimer's disease, and tuberculosis. In practical use, it can be administered according to clinical prescriptions, with administration methods including but not limited to intravenous injection, oral administration, pulmonary administration, inhalation spray, and transdermal delivery.

[0083] CCH nanocarriers also offer tagless, inherent fluorescence capabilities with strong emission in the visible light range, marking a key feature for practical experimental and interventional monitoring of nanocarriers and rapid drug tracking.

[0084] CCH nanocarriers exhibit pH-triggered release in slightly alkaline media, and significantly inhibit drug release even in highly corrosive acidic media. Therefore, CCH is a reasonable candidate material that can be used as a nanocarrier in microenvironments with a pH of neutral to alkaline, or as a fluorescent protective layer for goods with low pH values.

[0085] The method for preparing CCH in this application has been optimized, resulting in a process with minimal energy consumption and simple operation. The use of aqueous solutions avoids toxicity and pore contamination, eliminating any additional costs that might arise from toxicity or commonly used solvents, and successfully achieving mass production. Furthermore, CCH can be produced in various forms using common preparation methods, including but not limited to powders, colloids, films, and coatings. Therefore, CCH has the capability to be applied, cast, or coated onto a wide range of devices, including but not limited to drug delivery systems. This characteristic endows the final system with unique thermal diagnostic versatility. Thus, whether drug-loaded or drug-free, CCH can contact the target through, but not limited to, patches, implants, bandages, stents, catheters, or other implantable or non-implantable devices to achieve delivery, treatment, and / or diagnostic purposes.

[0086] The above description is only a partial embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for loading a drug delivery material, characterized in that, The process includes the following steps: suspending the target drug in an aqueous solution, adding the drug delivery material to the aqueous solution containing the target drug according to a set ratio, stirring the resulting suspension continuously for 48 hours, and centrifuging the suspension multiple times until the supernatant becomes clear. A manganese-based organic framework is used as a drug delivery material. The structure of the manganese-based organic framework is Mn2(TCPE)(H2O), wherein the TCPE is a fluorescent probe 1,1,2,2,-tetra(4-carboxyphenyl)ethylene. The preparation method of the manganese-based organic framework includes the following steps: 1) adding a manganese precursor to an appropriate amount of solvent; 2) diluting 1,1,2,2,-tetra(4-carboxyphenyl)ethylene with an appropriate amount of distilled water to obtain a ligand solution; 3) deprotonating the ligand solution; 4) gradually adding the deprotonated ligand solution from step 3) to the manganese precursor solution at a constant rate, and dividing the mixed solution into multiple experimental groups according to different temperatures for stirring; 5) after the mixed solution in step 4) has been stirred for a set time, allowing it to stand in the dark, washing and centrifuging the lower precipitate multiple times to obtain the manganese-based organic framework, and drying the obtained manganese-based organic framework in a vacuum oven.

2. The drug loading method for the drug delivery material according to claim 1, characterized in that, The manganese-based organic framework has a nanoscale size between 200 and 10 µm.

3. The drug loading method for the drug delivery material according to claim 1, characterized in that, Step 3) deprotonating the ligand solution includes adding potassium hydroxide or sodium hydroxide to the ligand solution for deprotonation.

4. The drug loading method for the drug delivery material according to claim 3, characterized in that, The ratio of the deprotonated solution to the ligand solution is in the range of 1:2 to 1:

4.

5. The method for loading a drug delivery material according to claim 1, characterized in that, The solvent content in the ligand solution does not exceed 1 / 4, and the solvent is distilled water.

6. The method for loading a drug delivery material according to claim 1, characterized in that, The stirring temperature range in step 4) is 25°C to 60°C.

7. The method for loading a drug delivery material according to claim 1, characterized in that, The stirring time in step 4) is 8 hours to 5 days.

8. The method for loading a drug delivery material according to claim 1, characterized in that, The formula for calculating the drug loading capacity of the drug delivery material is: LC% = (M T -M uT ) / (M T -M uT + M C ) 100%; The formula for calculating the drug loading efficiency of the drug delivery material is: LE% = (M T -M uT ) / M uT 100%; Among them, M T M uT and M C These are the total amount of target drug used in the formulation, the amount of unloaded target drug, and the amount of drug delivery material used, respectively.

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