A method for the preparation of a responsive multi-component material and its use in 129 Xe / 1 H dual-mode signal change

Abstract

The application belongs to the technical field of nuclear magnetic resonance spectroscopy, and particularly relates to a preparation method of a responsive multi-component material and application of the responsive multi-component material in 129 Xe / 1 H dual-mode signal change. The application synthesizes Fe3O4@SiO2@MnO2 nanoparticles by taking Fe3O4@SiO2 nanoparticles as a precursor and KMnO4 as a raw material, and the synthesized nanoparticles have complete morphology and uniform size. The transverse relaxation rate 1 / T2 signal of the multi-component material obtained through the strategy is quenched, 129 Xe has no change in the dissolved state signal, but after reacting with 10 mM glutathione, the 1 / T2 signal is restored, 129 Xe has a significant decrease in the dissolved state signal, and the 1 / T2 signal is restored, 129 Xe / 1 H dual-nuclear magnetic resonance signal change, and is of certain significance to the application of the hyperpolarized 129 Xe magnetic resonance probe and the development of multi-modal magnetic resonance imaging nano platforms.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of nuclear magnetic resonance spectroscopy, and particularly relates to a preparation method of a responsive multi-component material and application of the responsive multi-component material in 129 Xe / 1 H dual-mode signal changes. BACKGROUND

[0002] Magnetic resonance imaging (MRI) is a non-invasive imaging technique that can achieve high resolution and good tissue penetration, and plays an important role in the diagnosis and treatment of diseases. Traditional 1 H MRI uses protons in water in the body to image specific parts, and has low sensitivity and strong background interference. In order to improve the sensitivity of detection, the enhancement of MRI contrast agent can accelerate the relaxation process of protons by changing the local magnetic field, thereby improving the sensitivity and diagnostic accuracy of MRI, but is also limited by the background signal. Hyperpolarized 129 Xe magnetic resonance imaging is a new imaging method that has emerged in recent years. Because there is no Xe element in the body, hyperpolarized 129 Xe MRI does not have background signal interference. And through spin exchange optical pumping technology, the magnetic resonance signal of 129 Xe can be enhanced by more than 60,000 times, so as to realize lung magnetic resonance imaging, and obtain lung structure and function information, which can be used for evaluation of lung diseases in clinic. However, 129 Xe itself does not have specificity, and it is difficult to achieve specific detection of target objects. In order to utilize the direct magnetic resonance detection signal of hyperpolarized 129 Xe to achieve specific detection of target objects, researchers have developed cage molecules modified with targeting ligands to capture 129 Xe gas, such as calixbans, cucurbiturils, metal-organic frameworks (MOFs), etc. Among them, the most studied are calixban molecules and their derivatives, because they have good binding constants with 129 Xe and the advantages of easy modification of targeting ligands. However, the synthesis process of the molecule is complex, time-consuming, low-yield and poor biocompatibility, which makes it difficult to achieve in vivo application.

[0003] Fe3O4 nanoparticles have attracted much attention due to their outstanding advantages such as superparamagnetism, high specific surface area, low biotoxicity and flexible modifiability. The nanoparticles can accelerate the relaxation of protons by interfering with the magnetic field, thereby improving the MRI signal of protons. As an enhanced MRI contrast agent, Fe3O4 nanoparticles are usually designed into a core-shell structure with a magnetic core and a shell made of various materials (such as polydopamine, MnO2, SiO2 and graphene, etc.). The shell not only makes the chemical properties of the core more stable, but also enables further functionalization of the particles (such as polydopamine, MnO2, SiO2 and graphene, etc.). Among them, MnO2 nanoparticles have gradually become one of the preferred MRI contrast agent components due to their excellent biocompatibility, simple synthesis process, unique catalytic properties and magnetic resonance imaging properties. Duan et al. synthesized core-shell Fe3O4@C@MnO2 nanoprobe by spontaneous oxidation-reduction method, which was used as a pH-responsive T1 / T2 dual-mode MRI contrast agent. In the acidic PBS with a pH value of 5.0, the Fe3O4@C@MnO2 nanoprobe can quickly release Mn 2+ , and with the help of superparamagnetic nanoparticles Fe3O4, the T1 and T2 imaging is simultaneously enhanced. However, the diagnostic value of proton-based magnetic resonance imaging is hindered by low signal intensity, mainly due to the low nuclear spin polarization of protons. Hyperpolarized magnetic resonance imaging technology allows the contrast agent to detect MRI signal intensity up to 5 orders of magnitude, with high detection sensitivity. However, there is no report on the use of this material for responsive hyperpolarized Xe magnetic resonance contrast agent. SUMMARY

[0004] In view of the shortcomings of the currently commonly used 129 Xe magnetic resonance contrast agents such as cage molecules and their derivatives, which have complex synthesis process, low yield and poor biocompatibility, the present application provides a preparation method of a responsive multi-component material Fe3O4@SiO2@MnO2 and its application in 129 Xe / 1 H dual-mode signal changes. The material can cause 129 Xe / 1 H dual-mode signal changes under the activation of GSH, enriching and developing hyperpolarized 129 Xe magnetic resonance contrast agents, laying a foundation for future realization of in vivo hyperpolarized 129 Xe magnetic resonance imaging with high sensitivity and high specificity.

[0005] To achieve the above-mentioned purposes of the present application, the technical scheme adopted by the present application is as follows:

[0006] A preparation method of a responsive multi-component material: the responsive multi-component material is prepared by taking Fe3O4@SiO2 as a precursor and potassium permanganate as a raw material, and the specific steps are as follows: Fe3O4@SiO2 nanoparticles are uniformly dispersed in water, and then potassium permanganate solution is added for reaction; after the reaction is completed, centrifugation is performed, and the obtained precipitate is washed (preferably washed with deionized water for three times) and vacuum dried to obtain the responsive multi-component material.

[0007] The responsive multi-component material obtained by the preparation method is a ternary composite material Fe3O4@SiO2@MnO2 with a core-shell-shell structure, Fe3O4 as the core, a SiO2 shell layer wrapped outside the core, and MnO2 as the outermost shell layer.

[0008] Further, the Fe3O4@SiO2 nanoparticles are uniformly dispersed in water under ultrasonic waves, the ultrasonic power is 200 W, the ultrasonic time is 3-10 min, and preferably, the ultrasonic dispersion time is 5 min.

[0009] Further, the mass ratio of the Fe3O4@SiO2 nanoparticles and potassium permanganate is 1:0.8.

[0010] Further, the reaction conditions are as follows: the reaction temperature is room temperature, and the reaction time is 6-10 h, and preferably, the reaction time is 8 h.

[0011] Further, the above centrifugation conditions are all 10000 r / min centrifugation for 10 min.

[0012] Further, the above vacuum drying conditions are as follows: placed in a 50℃ vacuum drying box for drying for 24 h.

[0013] The application also provides the application of the responsive multi-component material obtained by the above preparation method in preparing GSH-responsive 129 Xe / 1 H dual-mode signal change reagents.

[0014] Further, the application is as follows: the multi-component material is used as a hyperpolarized 129 Xe magnetic resonance contrast agent.

[0015] The application finds that a Fe3O4@SiO2@MnO2 nanomaterial can realize the conversion of 1 H magnetic resonance signals and 129 Xe dissolved signals by interfering with the interaction of a magnetic field and Fe3O4. In the nanomaterial, due to the magnetic field shielding effect of MnO2, 1 H T2 magnetic resonance signals are quenched, 129 Xe dissolved signals are basically unchanged, but in a specific disease environment (such as a tumor microenvironment), MnO2 is reduced to Mn2+ This leads to the recovery of the proton's T2 signal and 129 The decrease in the dissolved state signal of Xe results in a darker image. Therefore, Fe3O4@SiO2@MnO2 nanomaterials can serve as a multifunctional contrast agent, capable of achieving contrast enhancement of target substances. 129 Xe / 1 Dual-mode imaging can significantly improve diagnostic accuracy, driving the development of multifunctional magnetic resonance nanoprobes. Furthermore, the synthesis process is simple, easy to modify, and safe. In addition, this multifunctional material can induce changes in magnetic resonance signals based on changes in GSH molecular levels during disease, revealing abnormalities such as GSH overexpression in tumor cells. This makes it highly promising for earlier and more accurate diagnosis of specific diseases and for monitoring disease progression.

[0016] Compared with the prior art, the beneficial effects and advantages of the present invention are as follows:

[0017] 1. Compared to traditional hyperpolarization based on cage-like molecules and their derivatives as the basic framework 129 Xe contrast agent: The contrast agent prepared by this invention can achieve hyperpolarization through interfering with a magnetic field. 129 The Xe magnetic resonance signal transition has the advantages of inexpensive raw materials, simple synthesis, easy modification, and safety.

[0018] 2. The material of this invention can achieve a visual signal transformation of specific disease biomarker molecules, compared to currently existing constant-brightness hyperpolarized materials. 129 Xe contrast agent: The contrast agent prepared by this invention can link specific changes in GSH in a disease with changes in magnetic resonance signals, and can intuitively visualize biochemical abnormalities in a disease, enabling earlier and more accurate diagnosis of specific diseases and monitoring of disease occurrence and development. Attached Figure Description

[0019] Figure 1 Transmission electron microscope (TEM) images of the Fe3O4, Fe3O4@SiO2, and Fe3O4@SiO2@MnO2 materials in Example 1;

[0020] Figure 2 The elemental distribution diagram of the Fe3O4@SiO2@MnO2 multi-component material in Example 1 is shown below.

[0021] Figure 3 The graph shows the changes in the transverse relaxation rate magnetic resonance signal of protons under the same conditions in the Fe3O4@SiO2, Fe3O4@SiO2@MnO2, and Fe3O4@SiO2@MnO2+10mM GSH solution systems.

[0022] Figure 4Dissolved state of Fe3O4@SiO2@MnO2 and Fe3O4@SiO2@MnO2+10mM GSH solution system under the same conditions 129 Xe magnetic resonance signal change diagram. DETAILED DESCRIPTION

[0023] The technical solutions of the present application will be described in detail by the applicant below in combination with specific examples.

[0024] The main reagents and instruments used in the following examples are as follows:

[0025] The reagents used in the following examples, sodium oleate, iron chloride hexahydrate, polyoxaethylene (5) nonyl phenyl ether (Igepal CO-520), tetraethyl silicate (TEOS), potassium permanganate, oleic acid, and 1-octadecene were all purchased from Aldrich Reagent Co., Ltd.; the reagents cyclohexane, anhydrous ethanol, and ammonium hydroxide (10M) were all purchased from National Pharmaceutical Group Chemical Reagent Co., Ltd. The nuclear magnetic resonance instrument was a 400MHz Bruker AV400 wide bore spectrometer.

[0026] Example 1:

[0027] Preparation of Fe3O4@SiO2@MnO2 multi-component material

[0028] (1) Preparation of Fe3O4 nanoparticles: sodium oleate (30mmol) and iron chloride hexahydrate (10mmol) were placed in a three-necked round-bottom flask, and then anhydrous ethanol (20mL), ultrapure water (15mL), and cyclohexane (35mL) were added in sequence. The resulting mixture was refluxed at 70°C for 4 hours to obtain iron oleate. Subsequently, the obtained iron oleate was dried in a vacuum drying oven (50°C, 48h), and then dissolved in 1-octadecene (8mL) and oleic acid (0.4mL). The resulting mixture was transferred to a programmed temperature heating jacket, stirred under the protection of a nitrogen atmosphere, and heated to 200°C at a rate of 4°C per minute, and maintained at 200°C for 20 minutes. After the reaction was cooled to room temperature (25°C, same below), 10mL of anhydrous ethanol was added, centrifuged at a speed of 10000 revolutions per minute for 10 minutes, and the precipitate was collected, followed by washing with anhydrous ethanol under the same conditions for three times. The supernatant was discarded, and the resulting product was dried in a vacuum drying oven at 50°C for 24h, which was Fe3O4 nanoparticles.

[0029] (2) Preparation of Fe3O4@SiO2 nanoparticles: Igepal CO-520 (0.25 mL) and Fe3O4 nanoparticles prepared in step (1) (0.75 mg) were dispersed in cyclohexane (5 mL) and stirred at room temperature for 15 min, then TEOS (1.2 μL) was added under stirring. After stirring for 30 min, a transparent, brown reverse microemulsion was formed. Ammonium hydroxide (20 μL) was then added and stirred at room temperature for another 18 h. After the reaction was completed, the precipitate was collected by centrifugation at 10,000 rpm for 10 min, then washed with anhydrous ethanol by centrifugation for 3 times, and dried in a vacuum oven at 50 °C for 24 h. The product obtained was Fe3O4@SiO2.

[0030] (3) Preparation of Fe3O4@SiO2@MnO2 multi-component material: Fe3O4@SiO2 was dispersed in 10 mL ultrapure water (1 mg / mL) and ultrasonicated for 10 min to make it uniformly dispersed, then stirred at room temperature for 10 min, after which 8 mL of potassium permanganate aqueous solution (1 mg / mL) was added dropwise under stirring, and stirred at room temperature for 8 h. After the reaction was completed, the precipitate was collected by centrifugation at 10,000 rpm for 10 min, then washed with ultrapure water by centrifugation for 2 times, and dried in a vacuum oven at 50 °C for 24 h. The product obtained was Fe3O4@SiO2@MnO2.

[0031] Characterization of multi-component material Fe3O4@SiO2@MnO2

[0032] The Fe3O4, Fe3O4@SiO2, Fe3O4@SiO2@MnO2 materials prepared in this example were characterized by transmission electron microscopy, and the TEM results of the obtained Fe3O4 nanoparticles are shown in Figure 1 (a), the TEM of the obtained Fe3O4@SiO2 nanoparticles is shown in Figure 1 (b), and the TEM of the obtained Fe3O4@SiO2@MnO2 multi-component material is shown in Figure 1 (c). It can be seen from the figure that the multi-component material prepared has a spherical morphology. Subsequently, the multi-component material powder prepared in this example was subjected to element mapping analysis, and the obtained powder element spectrum analysis results are shown in Figure 2 , which proves the presence of iron, silicon and manganese elements in the multi-component material.

[0033] Example 2: Test of multi-component material Fe3O4@SiO2@MnO2 in Xe / H dual mode signal change 129 Xe / 1 Test of H proton signal change 1 Test steps of H proton signal change

[0034] The dried multi-component material Fe3O4@SiO2@MnO2 prepared in Example 1 was taken and added into 1 mL ultrapure water, and ultrasonicated for 10 min at room temperature to make the multi-component material fully dispersed in the aqueous solution to obtain a dispersion liquid with Fe concentration of 1.5 mM. Then the solution was transferred into a nuclear magnetic sample tube to record the 1 / T2 value and obtain the T2 weighted magnetic resonance image by using a 400 MHz magnetic resonance imaging instrument. After that, in order to evaluate the responsiveness of the multi-component material to GSH, GSH was added into the above prepared solution to make the concentration of GSH be 10 mM, and ultrasonicated and mixed, and then placed for 30 min, and then the solution was transferred into a nuclear magnetic sample tube to record the 1 / T2 value of the sample and obtain the T2 weighted magnetic resonance image by using the same parameter setting. In order to form a control, the Fe3O4@SiO2 nanoparticle material prepared in Example 1 with Fe concentration of 1.5 mM was dispersed in 1 mL ultrapure water, and ultrasonicated for 10 min at room temperature to make it uniformly dispersed, and then the dispersion liquid was transferred into a nuclear magnetic sample tube to record the 1 / T2 value of the sample and obtain the T2 weighted magnetic resonance image by using the same parameter setting. The specific parameter settings are as follows:

[0035] T2 weighted imaging, repetition time (TR) = 2500 ms, echo time (TE) = 60 ms, slice thickness = 1 mm, slice spacing = 1 mm, FOV = 10 x 10 cm, matrix = 256 x 256;

[0036] T2 Map imaging, TR = 1000 ms, TE = 12-180 ms, slice thickness = 1 mm, slice spacing = 1 mm, FOV = 10 x 10 cm, matrix = 256 x 256.

[0037] Hyperpolarization 129 Xe signal change test steps

[0038] The dried multi-component material Fe3O4@SiO2@MnO2 prepared in Example 1 was taken and added into 2 mL ultrapure water, and ultrasonicated for 10 min at room temperature to make the multi-component material fully dispersed in the aqueous solution to obtain a dispersion liquid with Fe concentration of 1.5 mM. Then the solution was transferred into a nuclear magnetic sample tube to record the 1 / T2 value and obtain the T2 weighted magnetic resonance image by using a 400 MHz magnetic resonance imaging instrument 129 Xe signal spectrum. After that, in order to evaluate the responsiveness of the multi-component material to GSH, GSH was added into the above prepared solution to make the concentration of GSH be 10 mM, and ultrasonicated and mixed, and then placed for 30 min, and then the solution was transferred into a nuclear magnetic sample tube to record the 1 / T2 value of the sample and obtain the T2 weighted magnetic resonance image by using the same parameter setting. In order to form a control, the Fe3O4@SiO2 nanoparticle material prepared in Example 1 with Fe concentration of 1.5 mM was dispersed in 1 mL ultrapure water, and ultrasonicated for 10 min at room temperature to make it uniformly dispersed, and then the dispersion liquid was transferred into a nuclear magnetic sample tube to record the 1 / T2 value of the sample and obtain the T2 weighted magnetic resonance image by using the same parameter setting. The specific parameter settings are as follows: 129 Xe signal spectrum. After that, in order to evaluate the responsiveness of the multi-component material to GSH, GSH was added into the above prepared solution to make the concentration of GSH be 10 mM, and ultrasonicated and mixed, and then placed for 30 min, and then the solution was transferred into a nuclear magnetic sample tube to record the 1 / T2 value of the sample and obtain the T2 weighted magnetic resonance image by using the same parameter setting. In order to form a control, the Fe3O4@SiO2 nanoparticle material prepared in Example 1 with Fe concentration of 1.5 mM was dispersed in 1 mL ultrapure water, and ultrasonicated for 10 min at room temperature to make it uniformly dispersed, and then the dispersion liquid was transferred into a nuclear magnetic sample tube to record the 1 / T2 value of the sample and obtain the T2 weighted magnetic resonance image by using the same parameter setting. The specific parameter settings are as follows: 129 Xe signal spectrum. The specific parameter setting steps are as follows:

[0039] 129 The Xe nuclear magnetic resonance experiments were conducted on a 400 MHz (9.4 T) Bruker AV400 wide-aperture spectrometer (Bruker Biospin, Ettlingen, Germany) equipped with micro-imaging gradient coils, with an RF pulse frequency of 110.7 MHz for the Xe nuclei. 129 Xe NMR spectroscopy enables the use of a 10mm dual-resonance probe. 129 Xe and 1 H, PABBO 400W1 / S2 BB-HD-10Z), rectangular pulses with a flip angle (90°). Hyperpolarized pulses are generated using a continuous flow polarization device via spin-exchange optical pumping. 129 Xe gas. Nuclear spin polarization is approximately 20%. It is enriched by 10% N2, 88% He, and 2% Xe (Xe is 86% enriched by volume). 129 Xe or natural abundance 129 Xe, the natural abundance used in this embodiment. 129 A mixture of Xe and other gases was directly passed into a 10 mm NMR tube for 20 seconds, followed by a 3-second wait to ensure the bubbles had completely burst before signal acquisition. The sample temperature was set to 300 K on the NMR spectrometer.

[0040] Experimental results:

[0041] The experimental results of proton T2 magnetic resonance signal testing are as follows: Figure 3 As shown, from Figure 3 As can be seen, under the same Fe concentration, the proton transverse relaxation rate (1 / T2) of the multi-component material Fe3O4@SiO2@MnO2 is significantly lower than that of Fe3O4@SiO2. Correspondingly, the T2-weighted image is brighter than that of Fe3O4@SiO2, which is due to the magnetic field shielding effect of MnO2. However, when the Fe3O4@SiO2@MnO2 solution reacts with GSH, the redox reaction between MnO2 and GSH causes the MnO2 on the Fe3O4@SiO2 surface to decompose, resulting in the recovery of 1 / T2 and a darker T2-weighted image. Similarly, hyperpolarization... 129 The experimental results of Xe signal change test are as follows: Figure 4 As shown, due to the magnetic shielding of MnO2, which prevents Fe3O4 from interacting with the magnetic field, the Fe3O4@SiO2@MnO2 solution system... 129 Xe dissolved state signal intensity and pure aqueous solution 129 The Xe strength is comparable. However, when Fe3O4@SiO2@MnO2 reacts with a 10 mM GSH solution, the GSH degradation of the MnO2 shell causes interference with the magnetic field of the exposed Fe3O4@SiO2 material, leading to... 129The Xe signal is relaxed so that 129 The Xe solubility signal intensity decreases. This indicates that the multi-component material can be used to detect changes in GSH 129 Xe / 1 The change in the H and Xe dual-mode magnetic resonance signal can reveal abnormalities in disease such as overexpression of GSH in tumor cells, allowing earlier and more accurate diagnosis of disease, and enriching and developing hyperpolarized 129 Xe magnetic resonance contrast agents have important significance.

Claims

1. Use of a responsive multi-component material in preparing a GSH-responsive 129 Xe / 1 bimodal signal change reagent, wherein the responsive multi-component material is prepared by using Fe3O4@SiO2 as a precursor and KMnO4 as a raw material, and the specific steps are as follows: uniformly dispersing Fe3O4@SiO2 nanoparticles in water, then adding a KMnO4 solution for reaction; after the reaction is completed, centrifugation is performed, and the obtained precipitate is washed and vacuum dried to obtain the responsive multi-component material. The responsive multi-component material is a ternary composite material with a core-shell-shell structure, Fe3O4 as the core, a SiO2 shell layer outside the core, and MnO2 as the outermost shell layer; The mass ratio of the Fe3O4@SiO2 nanoparticles and KMnO4 is 1:0.

8. The reaction condition is that the reaction temperature is room temperature, and the reaction time is 6-10 h.

2. Use according to claim 1, characterized in that, The Fe3O4@SiO2 nanoparticles are uniformly dispersed in water under ultrasonic, the ultrasonic power is 200 W, and the ultrasonic time is 3-10 min.

3. Use according to claim 1, characterized in that, The centrifugal conditions are all centrifugation at 10000 r / min for 10 min.

4. Use according to claim 1, characterized in that, The vacuum drying condition is drying in a vacuum drying box at 50 DEG C for 24 h.

5. The use according to claim 1, characterized in that, Use of responsive multi-component materials as hyperpolarized 129 Xe magnetic resonance contrast agents.

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