Mn oxide protein nanoparticles for diagnosis and treatment integration, and preparation method and application thereof
The method of preparing manganese oxide protein nanoparticles in an aqueous phase in a one-step process solves the problems of cumbersome preparation steps and poor biocompatibility in existing technologies. It realizes nanoparticles with controllable particle size and good biocompatibility, thereby improving the accuracy of tumor treatment and diagnosis.
Patent Information
- Application Number
- CN202211585598.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-10
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2042-12-10
AI Technical Summary
Existing manganese oxide nanomedicines have complicated preparation steps, are difficult to control in terms of morphology, structure and size, and require surface modification to improve hydrophilicity and biocompatibility, which limits their application in biology.
Manganese oxide protein nanoparticles were prepared using a one-step aqueous phase method. By inducing redox reactions in the protein cavity, manganese oxides were allowed to grow controllably within the protein cavity, resulting in biocompatible and uniformly sized nanoparticles.
A simple preparation process was achieved, resulting in manganese oxide protein nanoparticles with controllable particle size and good biocompatibility. These nanoparticles possess strong imaging properties and diverse treatment modes, thereby improving the accuracy of tumor treatment and diagnosis.
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Figure CN115779104B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of biological medicine, and particularly relates to a manganese oxide protein nanoparticle and a preparation method and application thereof. BACKGROUND
[0002] Cancer seriously threatens human life and health, and is one of the most deadly diseases in the world, with an increasing incidence and mortality rate. In recent years, with the development of nanotechnology, more and more researchers have applied it to the treatment and monitoring of tumors and have made some breakthroughs, including the development of some nanocarriers with photoconversion effect, magnetic resonance imaging and immunotherapy drugs and many other nanomedicine systems. These drug systems can use significant photoconversion behavior to induce efficient photothermal and photodynamic therapy of tumors through near-infrared laser irradiation; at the same time, they can also use magnetic elements such as manganese to realize the visualization of tumors through high-resolution and soft-tissue contrast magnetic resonance imaging, thereby guiding the treatment of tumors. Therefore, constructing nanomedicine with integrated diagnosis and treatment functions has obvious advantages in improving the accuracy and effectiveness of tumor treatment. However, at present, the co-loading of therapeutic drugs and imaging probes in the carrier is mainly realized through chemical coupling or co-encapsulation, but these nanomedicines often have the shortcomings of difficult effective encapsulation, complex preparation process, use of non-pharmaceutical excipients, and interaction between different drugs, which significantly limits their clinical application.
[0003] Due to the controllable characteristics of their structure and morphology, unique physical and chemical properties, and excellent imaging performance, manganese oxide nanomaterials (MONs) and their derivatives have attracted more and more attention in the application of magnetic resonance imaging, biosensing, drug / gene delivery and tumor treatment. At present, manganese oxide nanomedicines are mainly prepared and synthesized by hydrothermal method, high-temperature oil phase decomposition method and other strategies. However, this method has complicated preparation steps, and the morphology, structure and size are not easy to control. In addition, surface modification treatment is often needed to improve the hydrophilicity and biocompatibility, which hinders the practical application of manganese oxide nanomaterials in biology. Therefore, in this field, there is an urgent need to develop a new type of manganese oxide protein nanoparticle with clinical application prospect and tumor targeting function, which can play the role of integrated diagnosis and treatment and realize accurate imaging and efficient treatment of tumors. SUMMARY
[0004] The purpose of the present application is to provide a manganese oxide protein nanoparticle and a preparation method and application thereof. The manganese oxide protein nanoparticle obtained by the simple preparation method has excellent imaging performance. The relaxation coefficient of the nanoparticle is increased from 0.6-1.4 mM -1 s -1 to 3.5-7.8 mM -1 s -1; in particular, the immune activation ability is unexpectedly improved.
[0005] The application adopts the following technical solutions:
[0006] A diagnosis and treatment integrated manganese oxide protein nanoparticle, which comprises manganese oxide and protein. Preferably, the diagnosis and treatment integrated manganese oxide protein nanoparticle is composed of manganese oxide and protein; the drug loading of the obtained diagnosis and treatment integrated manganese oxide protein nanoparticle is 1% to 50%, and the drug loading refers to the mass of manganese oxide / (mass of manganese oxide+mass of protein) in the sample after purification.
[0007] The application adopts protein as a nano reactor, induces redox reaction (such as permanganate ion and amino acid residues) in the protein cavity, and controls the growth of manganese oxide in the protein cavity, so as to obtain manganese oxide protein nanoparticles. Unlike traditional nano carriers, the application adopts a water phase one-step method to construct manganese oxide protein nanoparticles with good biocompatibility, double response characteristics, and size that can be accurately adjusted. The manganese oxide protein nanoparticles provided by the application have the advantages of simple preparation process, uniform size, controllable particle size, good biocompatibility, high tumor targeting, strong contrast performance, and various treatment modes, which lay a foundation for efficient tumor treatment and accurate tumor diagnosis.
[0008] The application provides a preparation method of the diagnosis and treatment integrated manganese oxide protein nanoparticle, which comprises the following steps: mixing a manganese salt aqueous solution and a protein aqueous solution to obtain a mixed solution, adjusting the pH value of the mixed solution to 4 to 12, purifying after reaction, and obtaining manganese oxide protein nanoparticles.
[0009] In the application, the protein comprises one or more of albumin, transferrin, hemoglobin, and low-density lipoprotein; and the manganese oxide comprises trimanganese tetraoxide. The manganese salt is permanganate, and the permanganate comprises one or more of potassium permanganate, calcium permanganate, and sodium permanganate.
[0010] In the application, the reaction temperature is 25 to 55 DEG C, the reaction time is 0.1 to 8 hours, preferably 0.5 to 4 hours, and the purification is centrifugal treatment in an ultrafiltration tube, and the centrifugal treatment speed is 1500 to 3000 rpm.
[0011] In the application, the molar ratio of the permanganate to the protein is (5 to 200):1, preferably (10 to 100):1, and further preferably (10 to 50):1; and the concentration of the protein aqueous solution is 1 to 50 mg / mL, preferably 5 to 25 mg / mL. The concentration of the permanganate aqueous solution is 10 to 30 mM.
[0012] In the application, the water as a solvent is preferably deionized water.
[0013] In the present application, the pH value of the mixed solution is adjusted by using NaOH aqueous solution or HCl solution, preferably the concentration of the NaOH aqueous solution or HCl solution is 0.1-0.3M.
[0014] The application discloses application of the above-mentioned manganese oxide protein nanoparticles in preparation of a reagent for improving a relaxation coefficient, in preparation of a tumor diagnosis and treatment reagent, in preparation of a tumor imaging probe, a tumor phototherapy drug and / or a tumor immunization reagent.
[0015] The present application successfully prepares the diagnosis and treatment integrated manganese oxide protein nanoparticles by using a water phase one-step preparation method for the first time, and the prepared nanoparticles are uniformly dispersed and have uniform particle sizes; the nanoparticles have good tumor microenvironment double-response characteristics, can non-linearly improve magnetic resonance imaging signals, and can simultaneously induce efficient phototherapy and immune activation effects. The present application regulates physical and chemical properties such as particle sizes and responsive drug release behaviors by limiting synthesis conditions such as a feeding ratio and a reaction time, and obtains responsive manganese oxide protein nanoparticles with controllable drug release characteristics. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 An electron microscope image of the manganese oxide protein nanoparticles prepared in Example One;
[0017] Figure 2 An electron microscope image of the manganese oxide protein nanoparticles prepared in Example Two;
[0018] Figure 3 An electron microscope image of the manganese oxide protein nanoparticles prepared in Example Three;
[0019] Figure 4 An X-ray diffraction spectrum of the manganese oxide protein nanoparticles prepared in Example One;
[0020] Figure 5 An X-ray photoelectron spectroscopy of the manganese oxide protein nanoparticles prepared in Example One;
[0021] Figure 6 A photothermal heating curve of the manganese oxide protein nanoparticles prepared in Example One;
[0022] Figure 7 Release curves of the manganese oxide protein nanoparticles prepared in Example One under different conditions;
[0023] Figure 8The relaxation coefficient spectra of the manganese oxide protein nanoparticles prepared in Example 1 under different conditions;
[0024] Figure 9 The images show enhanced magnetic resonance imaging (MRI) images and signal-to-noise ratio (SNR) statistics of the manganese oxide protein nanoparticles prepared in Example 1 against a human colon cancer HT-29 tumor model.
[0025] Figure 10 The flow cytometry plot shows the recruitment of natural killer cells in a mouse colon cancer CT-26 tumor model by manganese oxide protein nanoparticles prepared in Example 1.
[0026] Figure 11 The image shows the tumor inhibition curve of the manganese oxide protein nanoparticles prepared in Example 1 against the mouse colon cancer CT-26 tumor model over 30 days. Detailed Implementation
[0027] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention. The raw materials used in the present invention are all existing products, and the specific preparation operations and testing methods are conventional methods in the art and meet standard laboratory requirements. Animal experiments comply with the animal experiment operation requirements of Suzhou University. All data are expressed as mean ± standard deviation, and differences between groups were assessed using two-tailed Student's t-tests or Tukey post-hoc tests and one-way ANOVA. Statistical differences were defined as *P<0.05, **P<0.01, and ***P<0.001.
[0028] In existing technologies, manganese oxide nanomedicines are mostly prepared and synthesized using strategies such as hydrothermal methods and high-temperature oil-phase decomposition methods. These methods involve cumbersome preparation steps, making it difficult to control the morphology, structure, and size. Surface modification is often required to improve their hydrophilicity and biocompatibility, hindering the practical application of manganese oxide nanomaterials in biology. In this invention, a one-step aqueous preparation method was used to successfully prepare therapeutic manganese oxide protein nanoparticles. The obtained nanoparticles are uniformly dispersed and have a uniform particle size. The nanoparticles exhibit good dual-response characteristics to the tumor microenvironment, nonlinearly enhancing magnetic resonance imaging signals; simultaneously, they can induce highly efficient phototherapy and immune activation effects. The preparation method of the manganese oxide protein nanoparticles of this invention is as follows: a permanganate aqueous solution and a protein aqueous solution are mixed to obtain a mixture. The pH of the mixture is adjusted to 4-12, and after reaction, it is purified to obtain manganese oxide protein nanoparticles.
[0029] Example 1
[0030] The specific steps for preparing manganese oxide protein nanoparticles are as follows:
[0031] A 20 mM potassium permanganate aqueous solution and a 15.2 mg / mL transferrin (Trf) aqueous solution were thoroughly mixed at a volume ratio of 1:5, with a molar ratio of potassium permanganate to transferrin of 20:1. The pH of the mixed solution was adjusted to 10 using a 0.2 M NaOH aqueous solution. After reacting at room temperature for 4 hours, the mixture was added to an ultrafiltration tube (100 KD) and centrifuged at 2000 rpm to remove impurities, thus obtaining manganese tetroxide protein nanoparticles, which are manganese oxide protein nanoparticles.
[0032] Electron microscopy was performed on the prepared Trf-coated manganese oxide protein nanoparticles, and the results are as follows: Figure 1 As shown, the prepared nanoparticles are uniformly dispersed and have a uniform particle size; transmission electron microscopy shows that the core manganese oxide size is 7.4±0.5 nm, dynamic scattering test shows that the hydrated particle size is 37.2±4.2 nm, and the drug loading is 20%.
[0033] Example 2
[0034] The steps in this embodiment are the same as in Embodiment 1, except that the reaction time is 1 minute, and the prepared nanoparticles are imaged using an electron microscope. The results are as follows. Figure 2 As shown, the average particle size of the prepared nanoparticle core is 3.5 ± 0.1 nm.
[0035] Example 3
[0036] The steps in this embodiment are the same as in Embodiment 1, except that the reaction time is 10 min, and the prepared nanoparticles are imaged using an electron microscope. The results are as follows. Figure 3 As shown, the average particle size of the prepared nanoparticle cores is 5.2 ± 0.3 nm.
[0037] Example 4
[0038] The steps in this embodiment are the same as in Embodiment 1, except that the mixture is heated at 37 °C for 4 hours to obtain nanoparticle cores with an average particle size of 7.1 ± 0.3 nm.
[0039] Example 5
[0040] The steps in this embodiment are the same as in Embodiment 1, except that the mixture is heated at 55 °C for 4 hours to obtain nanoparticle cores with an average particle size of 6.1 ± 0.6 nm.
[0041] Example 6
[0042] The steps in this embodiment are the same as in Embodiment 1, except that: human serum albumin (HSA) solution is used as the protein solution to prepare HSA-encapsulated manganese oxide protein nanoparticles with an average particle size of 6.5 ± 0.7 nm.
[0043] Example 7
[0044] The steps in this embodiment are the same as in Embodiment 1, except that: a hemoglobin (Hb) solution is used as the protein solution to prepare hemoglobin-loaded manganese oxide protein nanoparticles with an average particle size of 4.3 ± 0.6 nm.
[0045] Example 8
[0046] The steps in this embodiment are the same as in Embodiment 1, except that: a low-density lipoprotein (LDL) solution is used as the protein solution to prepare manganese oxide protein nanoparticles loaded with LDL, with an average particle size of 5.1 ± 0.5 nm.
[0047] Example 9
[0048] The steps in this embodiment are the same as in Embodiment 1, except that: bovine serum albumin (BSA) solution is used as the protein solution to prepare BSA-encapsulated manganese oxide protein nanoparticles with an average particle size of 9.1 ± 0.8 nm.
[0049] The performance of the manganese oxide protein nanoparticles prepared in Example 1 was tested using the following methods:
[0050] 1. The physical structure of the manganese oxide protein nanoparticles prepared in Example 1 was tested. The specific steps were as follows: X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were performed on the prepared manganese oxide protein nanoparticles. XRD pattern ( Figure 4 The results showed that the prepared protein nanoparticles had similar characteristic peaks to manganese tetroxide, proving that the chemical composition of the nanoparticles was manganese tetroxide; XPS results ( Figure 5 The results indicate that the manganese oxide protein nanoparticles contain divalent and trivalent manganese ions, proving that the chemical composition of the nanoparticles is manganese tetroxide.
[0051] 2. The photothermal effect test of the manganese oxide protein nanoparticles prepared in Example 1 was conducted as follows: The manganese oxide protein nanoparticles were diluted with deionized water to different concentrations (0.5 mL each) of 0.2, 0.5, 1.0, and 2.0 mM. The nanoparticle solution was irradiated with a 785 nm laser at a laser power of 1.5 W / cm². 2 The temperature change of the solution was measured during 5 minutes of continuous irradiation, and the sample temperature was recorded every 30 seconds to obtain the photothermal heating curve. The results showed that ( Figure 6 Manganese oxide protein nanoparticles exhibit a good photothermal effect, and this effect is concentration-dependent. When the concentration of manganese oxide protein nanoparticles is 1.0 mM, the temperature rises by 14.9 °C after 5 minutes of light irradiation; when the concentration of manganese oxide protein nanoparticles is 2.0 mM, the temperature rises by 24.8 °C after 5 minutes of light irradiation, demonstrating the good photothermal effect of the nanoparticles and their potential for tumor phototherapy.
[0052] 3. The release behavior of the manganese oxide protein nanoparticles prepared in Example 1 was tested. The specific steps were as follows: Manganese oxide protein nanoparticles were diluted to 1.0 mM with different buffer solutions. Buffer solutions with physiological and tumor microenvironment pH (7.4, 6.5, 5.0) were used, and 1.0 mM GSH was added to simulate the tumor reducing microenvironment. 1.0 mL of the solution was placed in a dialysis bag (molecular weight cutoff of 3500), and the two ends were clamped with dialysis bag clamps before being placed in centrifuge tubes containing buffer solutions of different pH and GSH. The temperature was set at 37℃ and the shaking speed at 300 rpm to simulate the in vivo physiological environment. The receiving medium was removed and replaced with fresh medium at different time points. Subsequently, the Mn element in the receiving medium at different time points was quantified by ICP-MS, and the cumulative release amount was calculated. The results showed that ( Figure 7 The manganese oxide protein nanoparticles exhibit significant acid- and reduction-responsive release, with the highest release occurring in an acidic-reducing microenvironment. At pH 5.0, the nanoparticles release approximately 35% of the manganese; when pH 5.0 is maintained and 1.0 mM GSH is added, the nanoparticles release approximately 84% of the manganese, demonstrating the acidic and reduction-responsive nature of the manganese oxide protein nanoparticles.
[0053] 4. The relaxation coefficient r1 of the manganese oxide protein nanoparticles prepared in Example 1 was tested. The specific steps were as follows: Using manganese as the quantifier, the manganese oxide protein nanoparticles were diluted with different buffer solutions to different concentrations (0.05, 0.1, 0.2, 0.5, and 1.0 mM). Each concentration was incubated in triplicate. The T1 signal of the samples was scanned using a 1.5T magnetic resonance spectrometer to measure the T1 value of the solution, and the relaxation efficiency r1 of the manganese oxide protein nanoparticles was calculated. The results are as follows: Figure 8 As shown, the r1 of manganese oxide protein nanoparticles in pH 7.4 buffer is 0.6 mM. -1 s -1 The pH 6.5 group had a concentration of 1.8 mM. -1 s -1 The pH 5.0 group had a concentration of 3.5 mM. -1 s -1 Group R1 was 7.8 mM after co-incubation with pH 5.0 and 1.0 mM GSH. -1 s -1 This study demonstrated that the acidic and reduction-responsive properties of manganese oxide protein nanoparticles can significantly improve the relaxation coefficient, thereby enhancing the signal-to-noise ratio in tumor magnetic resonance imaging (MRI). Furthermore, compared to existing commercially available MRI contrast agents, the background relaxation coefficient of manganese oxide nanoparticles (0.6 mM) was significantly lower. -1 s -1 Compared to Gd-DTPA (3.2mM) -1 s -1 The lower value of the image background signal helps to reduce the image background signal and improve the image contrast.
[0054] As a control, a mixture of Mn(acac)₂ (0.3 g) and oleylamine (7.6 g) was reacted under nitrogen at 160 °C for 9 hours. The mixture was then centrifuged with ethanol (40.0 mL), and the brown precipitate was dissolved in hexane. Transferrin aqueous solution (15.0 mg / mL) was added with stirring. -1 The mixture was incubated overnight to obtain tMn3O4 NPs; these NPs lacked responsiveness, specifically, the relaxation coefficient did not change significantly under different pH and / or GSH incubation conditions (r1 increase was less than 0.1 mM). -1 s -1 Therefore, the diagnostic and therapeutic integrated manganese oxide protein nanoparticles obtained by this invention have a particular advantage in improving imaging contrast.
[0055] 5. The imaging performance of the manganese oxide protein nanoparticles prepared in Example 1 was tested using the following steps: Balb / c female nude mice with a subcutaneous tumor model of HT-29 (human colon cancer cells) were used (3 mice per group). The drug was administered via tail vein injection, with a dosage of 50 μmol kg of manganese. -1 Manganese oxide protein nanoparticles were scanned at different time points (0, 2, 6, 12, and 24 hours) using a clinically used 1.5T MRI scanner with the following parameters: TR / TE = 400 / 10ms, 256x256 matrices, slices = 5, thickness = 5mm, average = 3, and FOV = 60x60. Parallel experiments were conducted using Magendix, a clinically used MRI contrast agent, and the signal-to-noise ratio of MRI at the tumor site was calculated. Results are as follows: Figure 9 As shown, the results indicate that: 1) the magnetic resonance signal of the tumor site in the manganese oxide protein nanoparticle group gradually brightened over time, reaching its brightest point 24 hours after administration, with a signal-to-noise ratio of 242%, which was significantly higher than that in the same dose of the Magneto group, showing a significant tumor magnetic resonance imaging enhancement effect and a clear boundary between tumor tissue and normal tissue.
[0056] 6. The test of manganese oxide protein nanoparticles on natural killer cells (NK cells) was conducted as follows: Balb / c female mice with a subcutaneous tumor model of CT-26 (mouse colon cancer cells) were used (5 mice per group). The drug was administered via tail vein injection, with a dosage of 50 μmol / kg of manganese. -1 The manganese oxide protein nanoparticles were used to digest tumor cells 72 hours after injection, and single cells were collected. The cells were then labeled with CD45, CD3, and CD335 by flow cytometry, and the changes in the proportion of natural killer cells in the manganese oxide protein nanoparticle group were calculated by flow cytometry.
[0057] The manganese oxide protein nanoparticles were those loaded with TRF in Example 1 and those loaded with HSA in Example 6, respectively. The results are as follows: Figure 10 As shown, the results indicate that the manganese oxide protein nanoparticles in Example 1 significantly increased the proportion of NK cells in the tumor region, which was significantly higher than that of the saline control group and the HSA-coated manganese oxide protein nanoparticles, demonstrating a significant tumor immune activation ability and verifying the potential of manganese oxide protein nanoparticles as a tumor immunotherapy agent.
[0058] 7. The effect of manganese oxide protein nanoparticles on inhibiting tumor growth was tested. The specific steps were as follows: Balb / c female mice with a subcutaneous tumor model of CT-26 (mouse colon cancer cells) were used (5 mice in each experimental group). The drug was administered via tail vein injection, with a dosage of 50 μmol kg of manganese. -1 Manganese oxide protein nanoparticles were administered every two days for a total of three times. The initial tumor volume before administration and the tumor length and width for each mouse were recorded at regular time intervals after treatment, and tumor volume change curves were plotted. The manganese oxide protein nanoparticles used were the Trf-encapsulated manganese oxide protein nanoparticles from Example 1 and the HSA-encapsulated manganese oxide protein nanoparticles from Example 6. The results are as follows: Figure 11 As shown, after 12 days, the tumor volume of mice injected with saline increased by 13.2 times, the tumor volume of mice injected with free manganese chloride increased by 12.1 times, the tumor volume of mice injected with manganese oxide albumin nanoparticles increased by 9.5 times, and the tumor volume of mice injected with manganese oxide transferrin nanoparticles increased by 4.1 times. Manganese oxide transferrin nanoparticles significantly inhibited tumor growth and had a better tumor treatment effect than the free manganese chloride group and the manganese oxide albumin nanoparticle group.
[0059] Constructing nanomedicines with integrated diagnostic and therapeutic functions offers significant advantages for improving the accuracy of tumor monitoring and the efficacy of treatment. This invention demonstrates a manganese oxide protein nanoparticle that achieves high-contrast magnetic resonance imaging of tumors through synergistic tumor acidity / GSH-mediated cascade amplification of magnetic resonance signals and rapid elimination in normal tissues. Tumor-endocytic nanoprobes effectively sense the lysosomal microenvironment (pH approximately 5.0, GSH concentration approximately 1 mM), causing it to instantly decompose into Mn. 2+ Furthermore, the GSH response concentration threshold is approximately 0.12 mM, significantly enhancing the MRI signal and thus achieving high-contrast tumor imaging. Further, animal experiments revealed that the manganese oxide protein nanoparticles constructed from the preferred transferrin of this invention recruit NK cells at the tumor site by activating innate immune pathways, inducing immune activation to produce a tumor therapeutic effect, and achieving a significantly improved technical effect compared to albumin, for example... Figure 10 as well as Figure 11Taking HAS as an example, there was no statistically significant difference in performance between BSA-encapsulated manganese oxide protein nanoparticles and HSA-encapsulated manganese oxide protein nanoparticles. These findings demonstrate that responsive manganese oxide protein nanoparticles generate significant integrated tumor diagnosis and treatment functions by enhancing tumor-selective relaxation coefficients and inducing innate immune activation.
Claims
1. A therapeutic manganese oxide protein nanoparticle, characterized in that, The therapeutic manganese oxide protein nanoparticles comprise manganese oxide and protein; the protein is transferrin; the manganese oxide is manganese tetroxide; a mixture is prepared by mixing an aqueous solution of manganese salt and an aqueous solution of protein, which is then purified to obtain the therapeutic manganese oxide protein nanoparticles; the molar ratio of manganese salt to protein is (5-200):1; the concentration of the aqueous solution of protein is 1-50 mg / mL.
2. The therapeutically integrated manganese oxide protein nanoparticles according to claim 1, characterized in that, The drug loading of the therapeutic manganese oxide protein nanoparticles is 1% to 50%.
3. The method for preparing the therapeutically integrated manganese oxide protein nanoparticles according to claim 1, characterized in that, A mixture of manganese salt aqueous solution and protein aqueous solution was prepared to obtain a mixed solution. The pH of the mixed solution was adjusted to 4-12, and then the reaction was carried out. After purification, the integrated diagnostic and therapeutic manganese oxide protein nanoparticles were obtained. The protein was transferrin.
4. The method for preparing therapeutic manganese oxide protein nanoparticles according to claim 3, characterized in that, The reaction temperature was 25–55 °C, the reaction time was 0.1–8 hours, and purification was carried out using an ultrafiltration tube.
5. The method for preparing therapeutic manganese oxide protein nanoparticles according to claim 3, characterized in that, The manganese salt is a permanganate.
6. The method for preparing therapeutic manganese oxide protein nanoparticles according to claim 5, characterized in that, The permanganate includes one or more of potassium permanganate, calcium permanganate, and sodium permanganate.
7. The application of the therapeutic manganese oxide protein nanoparticles as described in claim 1 in the preparation of reagents that enhance relaxation coefficients.
8. The application of the therapeutic manganese oxide protein nanoparticles as described in claim 1 in the preparation of tumor diagnostic and therapeutic reagents.
9. The application of the therapeutic manganese oxide protein nanoparticles as described in claim 1 in the preparation of tumor imaging probes.
10. The application of the therapeutic manganese oxide protein nanoparticles as described in claim 1 in the preparation of phototherapy drugs for colon cancer.
11. The use of the therapeutic manganese oxide protein nanoparticles as described in claim 1 in the preparation of immunomodulators for treating colon cancer.