Multi-metal borate nanoparticles as well as preparation method and application thereof

Abstract

The invention discloses a multi-metal borate nano-particle as well as a preparation method and application thereof. The preparation method comprises the following steps: in the presence of small molecules with alkyl chains, performing high-temperature thermal decomposition on an organic metal compound or a metal salt compound precursor and organic borate in a solvent, and then centrifuging, modifying, performing ultrafiltration, dialyzing and purifying to obtain the multi-metal borate nanoparticles. The preparation method disclosed by the invention has the characteristics of mildness, high efficiency and strong controllability. The multi-metal borate nanoparticles prepared by the preparation method disclosed by the invention have the advantages of monodisperse size, relatively high magnetic property and good biocompatibility. Therefore, the prepared multi-metal borate nanoparticles not only have multi-modal imaging functions such as magnetic resonance imaging, near-infrared two-region imaging, nuclear medicine imaging and magnetic particle imaging, but also can be used for various treatment means such as magnetocaloric therapy and boron neutron capture therapy; potential advantages are realized in biomedical applications such as magnetic targeting tumor treatment and imaging contrast agents, and high practical values are realized.

Description

Technical Field

[0001] The invention belongs to the field of nano materials and biomedicine, and specifically relates to a polymetallic borate nanoparticle and a preparation method and application thereof. Background Art

[0002] Nowadays, cancer has become one of the leading causes of death worldwide, especially because it is difficult to be effectively diagnosed in the early stages and lacks highly targeted treatments, resulting in high recurrence rates and poor prognosis during treatment. How to achieve accurate diagnosis and treatment of tumors is one of the main research directions in current medicine and materials science. Accurate diagnosis and treatment of tumors requires not only precise positioning and imaging of the tumor site, but also highly selective treatment of the tumor to reduce damage to normal tissues.

[0003] In recent years, with the rapid development of nanotechnology and medical imaging technology, targeted therapy technology based on nanomaterials has made significant progress, especially in combination with magnetic targeted therapy, which has attracted widespread attention. Magnetic targeted therapy uses an external magnetic field to guide magnetic nanoparticles to gather in the tumor site in a targeted manner, thereby increasing the concentration of the drug and reducing systemic side effects. This method not only achieves precise drug delivery, but also directly enhances the therapeutic effect of the tumor site through magnetic field control.

[0004] Currently, targeted magnetic nanoparticles are often combined with multimodal imaging to achieve real-time monitoring of tumors. With the assistance of various imaging technologies such as magnetic resonance imaging (MRI), near-infrared zone II imaging (NIR-II), and magnetic particle imaging (MPI), accurate data support can be provided for real-time monitoring of tumor positioning and treatment effects. Therefore, the development of multifunctional nanomaterials with both imaging and treatment functions is an important way and direction to achieve accurate diagnosis and treatment of tumors.

[0005] Conventional magnetic nanoparticles, such as iron oxide (Fe 3 O 4 ) and other technologies have been initially applied in tumor imaging and magnetic targeted therapy. These particles can be guided by an external magnetic field to achieve a certain degree of aggregation at the tumor site. However, existing magnetic nanomaterials still have many shortcomings, such as weak magnetism, resulting in low efficiency in the targeted aggregation process; limited targeting and specificity, making it difficult to achieve the ideal tumor enrichment effect. These problems have greatly limited the further promotion and application of traditional magnetic nanomaterials in clinical practice.

[0006] At present, studies have also shown that multi-metal magnetic nanomaterials can have better magnetic properties and magnetic targeting than traditional single metal magnetic nanomaterials. However, the synthesis of existing multi-metal magnetic nanoparticles mostly uses a complex oil phase system, which requires multi-step reactions and multiple chemical reagents. Not only is the process cumbersome and the reaction conditions difficult to control, but the prepared particles are also difficult to maintain consistency in size and morphology, affecting their feasibility in clinical applications. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a polymetallic borate nanoparticle and a preparation method and application thereof. The polymetallic borate nanoparticle not only has multimodal imaging functions such as magnetic resonance imaging, near-infrared second-zone imaging, nuclear medicine imaging, and magnetic particle imaging, but can also be used for a variety of treatment methods such as magnetic thermal therapy and boron neutron capture therapy. It has high practical value and is expected to be applied in the biomedical field, especially in the precise diagnosis and treatment of tumors.

[0008] In order to solve the above technical problems, the present invention is implemented through the following technical solutions:

[0009] A method for preparing polymetallic borate nanoparticles comprises the following steps:

[0010] Step 1) dissolving an organic metal compound or metal salt compound as a precursor, a small molecule with an alkyl chain and an organic borate ester in a first solvent to form a first mixed reaction solution;

[0011] Step 2) dissolving the alcohol compound in a second solvent to form a second mixed reaction solution;

[0012] Step 3) Under the protection of inert gas, the first mixed reaction solution is heated to 50-150° C. at a certain stirring speed, and maintained for a period of time, and then heated to 200-350° C.;

[0013] Step 4) under the protection of inert gas, the second mixed reaction solution preheated to 50-150° C. is injected into the first mixed reaction solution heated in step 3), and after the temperature stabilizes to 200-350° C., the solution is kept warm for a period of time at a certain stirring speed to form a third mixed reaction solution;

[0014] Step 5) The third mixed reaction solution is naturally cooled to room temperature, and then centrifuged and purified to obtain polymetallic borate nanoparticles. The polymetallic borate nanoparticles have a size of 1 to 100 nanometers and are monodisperse.

[0015] Furthermore, in step 1), the organometallic compound is an organic complex containing a transition metal or a rare earth metal, such as an organic complex of iron, cobalt, nickel, manganese, neodymium or other lanthanide or actinide rare earth metals, and its ligands include acetylacetone, carbonyl, phenylacetylacetone, and cyclopentadiene.

[0016] Examples of the organometallic compound include, but are not limited to, iron triacetylacetonate, iron diacetylacetonate, iron pentacarbonyl, iron phenylacetylacetonate, neodymium triacetylacetonate, neodymium diacetylacetonate, neodymium pentacarbonyl, neodymium phenylacetylacetonate, manganese diacetylacetonate, manganese phenylacetylacetonate, nickel diacetylacetonate, nickel tetracarbonyl, cobalt diacetylacetonate, dicobalt octacarbonyl, gadolinium triacetylacetonate, gadolinium tricyclopentadienyl, dysprosium triacetylacetonate, holmium acetylacetonate, or a mixture of one or more thereof.

[0017] Furthermore, in step 1), the metal salt compound is a salt containing transition metals and rare earth metals or a hydrate thereof, such as oleates, stearates, fatty acid salts, trifluoroacetates, gluconates, citrates, oxalates, chlorides, sulfates, nitrates and hydrates thereof of iron, cobalt, nickel, manganese, neodymium or other lanthanide and actinide rare earth metals.

[0018] Examples of the metal salt compound include, but are not limited to, iron oleate, iron stearate, iron acetate, iron citrate, iron oxalate, ferric chloride, ferrous chloride, ferric chloride tetrahydrate, ferric chloride hexahydrate, ferric nitrate, ferric sulfate, neodymium oleate, neodymium stearate, neodymium acetate, neodymium citrate, neodymium oxalate, neodymium chloride, hydrated neodymium chloride, neodymium nitrate, neodymium sulfate, cobalt oleate, cobalt stearate, cobalt acetate, cobalt citrate, cobalt oxalate, cobalt decanoate, cobalt chloride, manganese acetate, oxalic acid Manganese, manganous chloride, manganese nitrate, manganese sulfate, gadolinium oleate, gadolinium stearate, gadolinium acetate, gadolinium chloride, gadolinium chloride trihydrate, gadolinium chloride hexahydrate, gadolinium nitrate, dysprosium acetate, dysprosium chloride, dysprosium chloride trihydrate, dysprosium chloride hexahydrate, dysprosium nitrate, holmium acetate, holmium chloride, holmium chloride trihydrate, holmium chloride hexahydrate, holmium nitrate, erbium acetate, erbium chloride, erbium chloride trihydrate, erbium chloride hexahydrate, erbium nitrate, thulium acetate, thulium chloride, thulium chloride trihydrate, thulium chloride hexahydrate, thulium nitrate, etc.

[0019] Furthermore, in step 1), the concentration of the organic metal compound or the inorganic metal salt compound is 0.001 to 1 mol / L;

[0020] Further, in step 1), the small molecule with an alkyl chain is one or more of a small molecule amine with an alkyl chain, a small molecule carboxylic acid with an alkyl chain, or a small molecule alcohol with an alkyl chain, and the CH 2 The number of units is 4 to 24; the small molecule with an alkyl chain may also be a derivative, analog or functional equivalent compound of the small molecule with an alkyl chain listed above.

[0021] Furthermore, in step 1), the concentration of the small molecule amine with an alkyl chain, the small molecule carboxylic acid with an alkyl chain or the small molecule alcohol with an alkyl chain is 0.001 to 1 mol / L.

[0022] Further, in step 1), the organic borate ester is one or more of trimethyl borate, triethyl borate, tripropyl borate, tributyl borate, tripentyl borate, trihexyl borate, triheptyl borate, trioctyl borate, trinonyl borate, and tridecyl borate, and the CH 2 The number of units is 1 to 24. The organic borates may also be derivatives, analogs or functional equivalent compounds of the organic borates listed above.

[0023] Furthermore, in step 1), the concentration of the organic borate is 0.001 to 1 mol / L.

[0024] Further, in step 1), the first solvent is one or a mixture of 1-hexadecene, 1-tetradecene, n-octadecane, n-hexadecane, paraffin oil, mineral oil, diphenyl ether, trioctylamine, dioctyl ether, oleylamine, 1-eicosene, 1-tetradecane. The first solvent may also be a derivative, analog or functional equivalent compound of the above-mentioned solvents.

[0025] Furthermore, in step 1), the molar ratio of the organic metal compound or metal salt compound to the organic borate ester is 1:(0.1-10).

[0026] Further, in step 2), the alcohol compound is one or more of octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol or pentadecanol, and the CH 2 The number of units is 4 to 24. The alcohol compound may also be a derivative, analog or functional equivalent compound of the alcohol compounds listed above.

[0027] Further, in step 2), the second solvent is one or a mixture of 1-hexadecene, 1-tetradecene, n-octadecane, n-hexadecane, paraffin oil, mineral oil, diphenyl ether, trioctylamine, dioctyl ether, oleylamine, 1-eicosene, 1-tetradecane. The second solvent may also be a derivative, analog or functional equivalent compound of the above-mentioned solvents.

[0028] Furthermore, in step 3), the inert gas is one or more of helium, neon, argon, xenon, krypton, and nitrogen.

[0029] Furthermore, in step 3), the stirring speed of the first mixed reaction solution is 100 to 1500 rpm, and the holding time after heating to 50 to 150° C. is 5 to 60 minutes.

[0030] Furthermore, in step 4), the inert gas is one or more of helium, neon, argon, xenon, krypton, and nitrogen.

[0031] Furthermore, in step 4), the stirring speed of the first mixed reaction solution and the second mixed reaction solution is 100 to 1500 rpm, and the insulation time after the temperature is stabilized to 200 to 350° C. is 1 minute to 36 hours.

[0032] Furthermore, in step 5), when the third mixed reaction solution is centrifuged, the precipitant added to the third mixed reaction solution is one or a combination of ethanol, methanol, and acetone; and the volume of the precipitant is 2 to 50 times the volume of the third mixed reaction solution. The precipitate is separated by magnetic separation or centrifugal separation technology.

[0033] Furthermore, in step 5), the method for separating the precipitate is: using the precipitant to cyclically clean and separate the precipitate once or multiple times. This can improve the purity of the obtained magnetic nanoparticle product. The number of cycles of cleaning and separation can be 1 to 5 times. The separation of the magnetic nanoparticles can be carried out by magnetic separation or centrifugal separation.

[0034] The method for preparing the polymetallic borate nanoparticles of the present invention can further prepare water-soluble polymetallic borate nanoparticles, comprising the following subsequent steps:

[0035] Step 6) dissolving the polymetallic borate nanoparticles obtained in step 5) in a third solvent, adding biocompatible molecules, and then stirring at a certain stirring speed, heating at 40 to 100° C. or ultrasonicating for a period of time to form a fourth mixed reaction solution;

[0036] Step 7) The fourth mixed solution is naturally cooled to room temperature, and then centrifuged and purified to obtain water-soluble polymetallic borate nanoparticles. The water-soluble polymetallic borate nanoparticles have a size of 1 to 100 nanometers and are monodisperse.

[0037] Furthermore, in step 6), the third solvent is one of dichloromethane, chloroform, tetrahydrofuran, ethyl acetate, ethylene glycol, dimethyl ether, dioxane, pyridine, dimethylformamide, dimethyl sulfoxide, or a mixture of any two thereof.

[0038] Furthermore, in step 6), the biocompatible molecule is one or more of bovine serum albumin, human serum albumin, dextran, polyethylene glycol, polyvinyl pyrrolidone, polyethyleneimine, chitosan or derivatives of the above-listed biocompatible molecules.

[0039] Furthermore, in step 6), the polymetallic borate nanoparticles and the biocompatible molecules are stirred in the third solvent at a speed of 100 to 1500 rpm, and the heating or ultrasonication at 40 to 100° C. lasts for 10 minutes to 48 hours.

[0040] Furthermore, in step 7), when the fourth mixed reaction solution is centrifuged, the precipitant added to the fourth mixed reaction solution is one or a combination of cyclohexane, n-hexane, benzene, and toluene; and the volume of the precipitant is 2 to 50 times the volume of the fourth mixed reaction solution. The precipitate is separated by magnetic separation or centrifugal separation technology.

[0041] Furthermore, in step 7), the method for separating the precipitate is: using the precipitant to cyclically clean and separate the precipitate once or multiple times. This can improve the purity of the obtained magnetic nanoparticle product. The number of cycles of cleaning and separation can be 1 to 5 times. The separation of magnetic nanoparticles can be carried out by magnetic separation or centrifugal separation.

[0042] A polymetallic borate nanoparticle or a water-soluble polymetallic borate nanoparticle is prepared by the above preparation method. The prepared polymetallic borate nanoparticle or the water-soluble polymetallic borate nanoparticle has good magnetic targeting performance and biocompatibility, and can be used for tumor diagnosis and treatment.

[0043] Furthermore, the polymetallic borate nanoparticles or the water-soluble polymetallic borate nanoparticles have a size of 1 to 100 nanometers and are monodisperse.

[0044] The application of polymetallic borate nanoparticles or water-soluble polymetallic borate nanoparticles prepared by the above preparation method in the precise targeted treatment of tumors, especially in combined treatments such as magnetic resonance imaging (MRI), near-infrared zone II imaging, nuclear medicine imaging, magnetic particle imaging, magnetic thermal therapy and boron neutron capture therapy, can significantly improve the diagnostic accuracy and treatment effect of tumors.

[0045] The polymetallic borate nanoparticles or water-soluble polymetallic borate nanoparticles prepared by the above preparation method can be used as a carrier for tumor targeted delivery to achieve effective drug delivery, and can also be used as a synergist in magnetic thermal therapy, and have broad biomedical application prospects.

[0046] The beneficial effects of the present invention are:

[0047] The present invention synthesizes polymetallic borate nanoparticles in one step by a thermal decomposition method. The materials used are organic metal compounds or metal salt compound precursors and organic borate esters. The reaction conditions are mild, and no complicated multi-step reaction process is required. The operation is simple and easy to achieve large-scale preparation, and the yield is high. The prepared polymetallic borate nanoparticles have good magnetism and biocompatibility. Through the guidance of an external magnetic field, efficient enrichment of tumor sites can be achieved, thereby enhancing the effect of targeted therapy. The rare earth elements in the nanoparticles give the material near-infrared second zone imaging (NIR-II) capability. This imaging mode has a greater tissue penetration depth and higher imaging resolution, which helps to achieve accurate positioning and real-time monitoring of deep tumors.

[0048] The polymetallic borate nanoparticles of the present invention also contain borate ions, which can be used for boron neutron capture therapy (BNCT). By inducing a nuclear reaction after boron atoms capture neutrons, alpha particles with high linear energy are released, thereby selectively killing tumor cells with less damage to normal tissues, and are particularly suitable for the treatment of certain refractory tumors. In addition, the nanoparticles of the present invention can be used as drug carriers for targeted delivery and magnetic thermal therapy synergists in tumor treatment, significantly increasing the concentration of drugs at the tumor site and reducing side effects on normal tissues. Overall, the nanoparticles have broad biomedical application prospects in the precise diagnosis and personalized treatment of tumors.

[0049] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. The specific implementation of the present invention is given in detail by the following embodiments and their accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0051] Figure 1 The transmission electron microscope image (a), high-resolution electron microscope image (b), particle size statistics image (c), powder diffraction image (d), STEM-Mapping image (eh), and XPS image (il) of the NdFeB nanoparticles prepared in Example 1 of the present invention.

[0052] Figure 2 The following are the photograph (a) of the solution of NdFeB nanoparticles prepared in Example 1 of the present invention under a magnetic field, the saturation magnetization curve (b), the low-field saturation magnetization curve (c), the near-infrared second-zone luminescence diagram (d), the ultraviolet absorption spectrum diagram (e), and the fluorescence spectrum diagram (f).

[0053] Figure 3 The transmission electron microscope image (a) of the water-soluble NdFeB nanoparticles prepared in Example 2 of the present invention, the hydrated particle size image (b), the hydrated particle size change image (c), the photo of the solution under a magnetic field (d), the saturation magnetization curve image (e), and the low-field saturation magnetization curve image (f).

[0054] Figure 4 The magnetic resonance imaging image (a), relaxation rate image (b), near-infrared second-zone luminescence image (c), ultraviolet absorption spectrum image (d), and fluorescence spectrum image (f) of the water-soluble neodymium iron borate nanoparticles prepared in Example 2 of the present invention.

[0055] Figure 5 This is a photo of a SPECT scan performed by placing an N52 NdFeB permanent magnet on the right tumor of a mouse in Example 3 of the present invention.

[0056] Figure 6 This is a SPECT-CT image of a C57BL / 6 black mouse with subcutaneous melanoma injected with 99mTc-labeled water-soluble NdFeB nanoparticles in Example 3 of the present invention.

[0057] Figure 7 This is the time-dependent signal of 99mTc-labeled water-soluble NdFeB nanoparticles in two tumors of mice in Example 3 of the present invention. DETAILED DESCRIPTION

[0058] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings so that the purpose, features and advantages of the invention can be more clearly understood. It should be understood that the embodiments shown in the accompanying drawings are not intended to limit the scope of the present invention, but are only intended to illustrate the essential spirit of the technical solution of the present invention.

[0059] In the following description, certain specific details are set forth for the purpose of illustrating various disclosed embodiments to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of these specific details. In other cases, well-known devices, structures, and techniques associated with the present application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0060] Unless the context requires otherwise, throughout the specification and claims, the word "comprise" and variations such as "include" and "have" should be construed in an open, inclusive sense, ie, should be interpreted as "including, but not limited to."

[0061] References throughout the specification to "one embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of "in one embodiment" or "in an embodiment" in various places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any manner in one or more embodiments.

[0062] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally employed in its sense including "and / or" unless the context clearly dictates otherwise.

[0063] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. Unless otherwise specified, the reagents and materials used in the present invention are commercially available.

[0064] The present invention has developed a multi-metal borate nanoparticle with good magnetic targeting performance and biocompatibility. The nanoparticle includes borate nanoparticles containing one or more metal elements, wherein the metal elements are iron, neodymium, manganese, copper, dysprosium, terbium and other rare earth or transition metals and combinations thereof. The nanoparticle is prepared by high-temperature thermal decomposition of an organic metal compound or a metal salt compound as a precursor with an organic borate in a solvent in the presence of a small molecule with an alkyl chain.

[0065] The preparation method of the polymetallic borate nanoparticles of the present invention is specifically as follows:

[0066] Step 1) dissolving an organic metal compound or metal salt compound as a precursor, a small molecule with an alkyl chain and an organic borate ester in a first solvent to form a first mixed reaction solution.

[0067] The organometallic compound is an organic complex containing a transition metal or a rare earth metal, such as an organic complex of iron, cobalt, nickel, manganese, neodymium or other lanthanide and actinide rare earth metals, and its ligands include acetylacetone, carbonyl, phenylacetylacetone, and cyclopentadiene. Examples of the organometallic compound include, but are not limited to, a mixture of one or more of triacetylacetonato iron, diacetylacetonato iron, pentacarbonyl iron, phenylacetylacetonato iron, triacetylacetonato neodymium, diacetylacetonato neodymium, pentacarbonyl neodymium, phenylacetylacetonato neodymium, diacetylacetonato manganese, phenylacetylacetonato manganese, diacetylacetonato nickel, tetracarbonyl nickel, diacetylacetonato cobalt, octacarbonyl dicobalt, triacetylacetonato gadolinium, tricyclopentadiene gadolinium, triacetylacetonato dysprosium, and acetylacetonato holmium.

[0068] The metal salt compound is a salt or hydrate containing a transition metal and a rare earth metal, such as oleate, stearate, fatty acid salt, trifluoroacetate, gluconate, citrate, oxalate, chloride, sulfate, nitrate and hydrate thereof of iron, cobalt, nickel, manganese, neodymium or other lanthanide and actinide rare earth metals. Examples of the metal salt compound include, but are not limited to, iron oleate, iron stearate, iron acetate, iron citrate, iron oxalate, ferric chloride, ferrous chloride, ferrous dichloride, ferrous chloride tetrahydrate, ferric chloride hexahydrate, ferric nitrate, ferric sulfate, neodymium oleate, neodymium stearate, neodymium acetate, neodymium citrate, neodymium oxalate, neodymium trichloride, hydrated neodymium trichloride, neodymium nitrate, neodymium sulfate, cobalt oleate, cobalt stearate, cobalt acetate, cobalt citrate, cobalt oxalate, cobalt decanoate, cobalt chloride, manganese acetate, oxalic acid Manganese, manganous chloride, manganese nitrate, manganese sulfate, gadolinium oleate, gadolinium stearate, gadolinium acetate, gadolinium chloride, gadolinium chloride trihydrate, gadolinium chloride hexahydrate, gadolinium nitrate, dysprosium acetate, dysprosium chloride, dysprosium chloride trihydrate, dysprosium chloride hexahydrate, dysprosium nitrate, holmium acetate, holmium chloride, holmium chloride trihydrate, holmium chloride hexahydrate, holmium nitrate, erbium acetate, erbium chloride, erbium chloride trihydrate, erbium chloride hexahydrate, erbium nitrate, thulium acetate, thulium chloride, thulium chloride trihydrate, thulium chloride hexahydrate, thulium nitrate, etc.

[0069] The small molecule with an alkyl chain is one or more of a small molecule amine with an alkyl chain, a small molecule carboxylic acid with an alkyl chain, or a small molecule alcohol with an alkyl chain, and the CH 2 The number of units is 4 to 24; the small molecule with an alkyl chain may also be a derivative, analog or functional equivalent compound of the small molecule with an alkyl chain listed above.

[0070] The organic borate ester is one or more of trimethyl borate, triethyl borate, tripropyl borate, tributyl borate, tripentyl borate, trihexyl borate, triheptyl borate, trioctyl borate, trinonyl borate, and tridecyl borate, and the CH 2 The number of units is 1 to 24. The organic borates may also be derivatives, analogs or functional equivalent compounds of the organic borates listed above.

[0071] The first solvent is one or a mixture of 1-hexadecene, 1-tetradecene, n-octadecane, n-hexadecane, paraffin oil, mineral oil, diphenyl ether, trioctylamine, dioctyl ether, oleylamine, 1-eicosene, 1-tetradecane. The first solvent may also be a derivative, analog or functional equivalent compound of the above-mentioned solvents.

[0072] The concentration of the organometallic compound or inorganic metal salt compound is 0.001 to 1 mol / L. The concentration of the small molecule amine with an alkyl chain, the small molecule carboxylic acid with an alkyl chain, or the small molecule alcohol with an alkyl chain is 0.001 to 1 mol / L. The concentration of the organic borate ester is 0.001 to 1 mol / L. The molar ratio of the organometallic compound or metal salt compound to the organic borate ester is 1:(0.1 to 10).

[0073] Step 2) dissolving the alcohol compound in a second solvent to form a second mixed reaction solution.

[0074] The alcohol compound is one or more of octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol or pentadecanol, and the CH 2 The number of units is 4 to 24. The alcohol compound may also be a derivative, analog or functional equivalent compound of the alcohol compounds listed above.

[0075] The second solvent is one or a mixture of 1-hexadecene, 1-tetradecene, n-octadecane, n-hexadecane, paraffin oil, mineral oil, diphenyl ether, trioctylamine, dioctyl ether, oleylamine, 1-eicosene, 1-tetradecane. The second solvent may also be a derivative, analog or functional equivalent compound of the above-mentioned solvents.

[0076] Step 3) Under the protection of one or more inert gases selected from helium, neon, argon, xenon, krypton and nitrogen, the first mixed reaction solution is heated to 50-150° C. at a stirring speed of 100-1500 rpm, maintained for 5-60 minutes, and then heated to 200-350° C.

[0077] Step 4) Under the protection of one or more inert gases selected from helium, neon, argon, xenon, krypton, and nitrogen, the second mixed reaction solution preheated to 50 to 150° C. is injected into the first mixed reaction solution heated in step 3), and after the temperature stabilizes to 200 to 350° C., the mixture is kept warm at a stirring speed of 100 to 1500 rpm for 1 minute to 36 hours to form a third mixed reaction solution.

[0078] Step 5) The third mixed reaction solution is naturally cooled to room temperature, and then centrifuged and purified to obtain polymetallic borate nanoparticles. The polymetallic borate nanoparticles have a size of 1 to 100 nanometers and are monodisperse.

[0079] The precipitant added to the third mixed reaction solution is one or a combination of ethanol, methanol, and acetone; and the volume of the precipitant is 2 to 50 times the volume of the third mixed reaction solution. The precipitate is separated by magnetic separation or centrifugal separation technology.

[0080] The method for separating the precipitate is: using the precipitant to cyclically clean and separate the precipitate once or multiple times. This can improve the purity of the obtained magnetic nanoparticle product. The number of cycles of cleaning and separation can be 1 to 5 times. The separation of the magnetic nanoparticles can be carried out by magnetic separation or centrifugal separation.

[0081] The present invention can further prepare water-soluble polymetallic borate nanoparticles, comprising the following subsequent steps:

[0082] Step 6) dissolving the polymetallic borate nanoparticles obtained in step 5) in a third solvent, adding biocompatible molecules, and then stirring at 100 to 1500 rpm, heating at 40 to 100° C. or ultrasonicating for 10 minutes to 48 hours to form a fourth mixed reaction solution.

[0083] The third solvent is one of dichloromethane, chloroform, tetrahydrofuran, ethyl acetate, ethylene glycol, dimethyl ether, dioxane, pyridine, dimethylformamide, and dimethyl sulfoxide, or a mixture of any two of them.

[0084] The biocompatible molecule is one or more of bovine serum albumin, human serum albumin, dextran, polyethylene glycol, polyvinyl pyrrolidone, polyethylene imine, chitosan or derivatives of the above-listed biocompatible molecules.

[0085] Step 7) The fourth mixed solution is naturally cooled to room temperature, and then centrifuged and purified to obtain water-soluble polymetallic borate nanoparticles. The water-soluble polymetallic borate nanoparticles have a size of 1 to 100 nanometers and are monodisperse.

[0086] The precipitant added to the fourth mixed reaction solution is one or a combination of cyclohexane, n-hexane, benzene and toluene; and the volume of the precipitant is 2 to 50 times the volume of the fourth mixed reaction solution. The precipitate is separated by magnetic separation or centrifugal separation technology.

[0087] The method for separating the precipitate is: using the precipitant to cyclically clean and separate the precipitate once or multiple times. This can improve the purity of the obtained magnetic nanoparticle product. The number of cycles of cleaning and separation can be 1 to 5 times. The separation of the magnetic nanoparticles can be carried out by magnetic separation or centrifugal separation.

[0088] The preparation method of the polymetallic borate nanoparticles of the present invention and the related test results are described in detail below with reference to specific examples.

[0089] Example 1 Preparation of NdFeB Nanoparticles:

[0090] The preparation method of NdFeB nanoparticles is as follows:

[0091] Step 1) 0.75 mmol of neodymium acetylacetonate, 0.75 mmol of iron acetylacetonate, and 0.75 mmol of tributyl borate are dissolved in 20 mL of 1-octadecene to form a mixed reaction solution 1;

[0092] Step 2) dissolving hemp alcohol in 7 mL of 1-octadecene to form a mixed reaction solution 2;

[0093] Step 3) Under argon protection, solution 1 was heated to 110° C. at a stirring speed of 500 rpm and maintained for 30 minutes, and then heated to 320° C.;

[0094] Step 4) Under argon protection, solution 2 preheated to 80° C. was injected into solution 1, and after the temperature stabilized to 320° C., the mixture was kept warm at a stirring speed of 500 rpm for 1 hour;

[0095] Step 5) After cooling naturally to room temperature, add 2 volumes of acetone and centrifuge the precipitate. Wash the precipitate three times to obtain purified NdFeB nanoparticles, dissolve them in cyclohexane and store them at 4°C.

[0096] The prepared NdFeB nanoparticles were tested as follows, and the following test results were obtained:

[0097] See also Figure 1 As shown in a, Figure 1 a is a transmission electron microscope image of the NdFeB nanoparticles prepared in this example. Figure 1 It can be seen from a that the NdFeB nanoparticles prepared in this example have a monodisperse size.

[0098] See also Figure 1 As shown in b, Figure 1 b is a high-resolution electron microscope image of the NdFeB nanoparticles prepared in this example. Figure 1 It can be seen from b that the NdFeB nanoparticles prepared in this example have excellent crystallinity.

[0099] See also Figure 1 As shown in c, Figure 1 c is a statistical diagram of the particle size of the NdFeB nanoparticles prepared in this example. Figure 1 It can be seen from Figure c that the NdFeB nanoparticles prepared in this example have excellent monodispersity, with an average particle size of 7.7 nm and a size standard deviation of 10.4%.

[0100] See also Figure 1 As shown in d, Figure 1 d is the powder diffraction pattern of the NdFeB nanoparticles prepared in this example. Figure 1 It can be seen from d that the NdFeB nanoparticles prepared in this example do not match borates and NdB.

[0101] See also Figure 1 e- Figure 1 As shown in h, Figure 1 e- Figure 1 h is the STEM-Mapping image of the NdFeB nanoparticles prepared in this example. Figure 1 e- Figure 1 It can be seen from Figure h that the NdFeB nanoparticles prepared in this example contain two metal elements, Fe and Nd.

[0102] See also Figure 1 i- Figure 1 As shown in l, Figure 1 i- Figure 1 l is the XPS graph of the NdFeB nanoparticles prepared in this example. Figure 1 i- Figure 1 It can be seen from Figure 1 that the NdFeB nanoparticles prepared in this embodiment contain four elements: Fe, Nd, B and O.

[0103] See also Figure 2 a- Figure 2 As shown in c, Figure 2 a- Figure 2 c are respectively a photograph of the NdFeB nanoparticles obtained in this embodiment being attracted by a magnet, a saturation magnetization curve, and a low-field saturation magnetization curve. Figure 2 a- Figure 2 It can be seen from c that the NdFeB nanoparticles prepared in this example have excellent magnetic properties, and the saturation magnetization intensity is as high as 103.4emu / g.

[0104] See also Figure 2 d- Figure 2 As shown in f, Figure 2 d- Figure 2 f are respectively the near-infrared second-zone luminescence graph, ultraviolet absorption spectrum graph, and fluorescence spectrum graph of the NdFeB nanoparticle sample prepared in this embodiment. Figure 2 d- Figure 2 It can be seen from FIG. 5 that the NdFeB nanoparticles prepared in this example have excellent near-infrared second-zone luminescence performance.

[0105] Example 2 Preparation of water-soluble NdFeB nanoparticles:

[0106] Based on Example 1, the preparation method of water-soluble NdFeB nanoparticles is as follows:

[0107] Step 6) 10 mg of NdFeB nanoparticles were dissolved in 4 mL of tetrahydrofuran to form a solution, 100 mg of bisphosphonic acid polyethylene glycol with a molecular weight of 2000 was added, and the solution was stirred at 500 rpm and heated at 50° C. for 24 hours.

[0108] Step 7) After cooling naturally to room temperature, add 2 times the volume of cyclohexane and centrifuge the precipitate. Wash it three times in a cycle to obtain purified water-soluble NdFeB nanoparticles, dissolve it in deionized water, and store it at 4°C.

[0109] The prepared water-soluble NdFeB nanoparticles were tested as follows, and the following test results were obtained:

[0110] See also Figure 3 As shown in a, Figure 3 a is a transmission electron microscope image of the water-soluble NdFeB nanoparticles prepared in this example. Figure 3 It can be seen from a that the water-soluble NdFeB nanoparticles prepared in this example have a monodisperse size.

[0111] See also Figure 3 As shown in b, Figure 3 b is the hydrated particle size diagram of the water-soluble NdFeB nanoparticles prepared in this example. Figure 3 It can be seen from b that the kinetic size of the water-soluble NdFeB nanoparticles prepared in this example is 27.6 nm.

[0112] See also Figure 3 As shown in c, Figure 3 c is a graph showing the change in hydrated particle size of water-soluble NdFeB nanoparticles prepared in this example. Figure 3 As can be seen from c, the kinetic size of the water-soluble NdFeB nanoparticles prepared in this example did not change significantly within 30 days, showing excellent colloidal stability.

[0113] See also Figure 3 e- Figure 3 As shown in f, Figure 3 e- Figure 3 f is the saturation magnetization curve of the water-soluble NdFeB nanoparticles prepared in this example. Figure 3 e- Figure 3 It can be seen from figure f that the water-soluble NdFeB nanoparticles prepared in this example have excellent magnetic properties, and the saturation magnetization intensity is as high as 132.7emu / g.

[0114] See also Figure 4 a- Figure 4 As shown in b, Figure 4 a- Figure 4 b are the magnetic resonance imaging images and relaxation rates of the water-soluble NdFeB nanoparticles prepared in this example, respectively. Figure 4 a- Figure 4 It can be seen from b that the water-soluble NdFeB nanoparticles prepared in this example have excellent T2 imaging performance.

[0115] See also Figure 4 d- Figure 4As shown in f, Figure 4 d- Figure 4 f are respectively the near-infrared second-zone luminescence graph, ultraviolet absorption spectrum graph, and fluorescence spectrum graph of the water-soluble NdFeB nanoparticles prepared in this embodiment. Figure 4 d- Figure 4 It can be seen from FIG. 5 that the water-soluble NdFeB nanoparticles prepared in this example have excellent near-infrared second-zone luminescence performance.

[0116] Example 3 Detection of magnetic targeting effect of water-soluble NdFeB nanoparticles:

[0117] The magnetic targeting effect of the water-soluble NdFeB nanoparticles prepared in Example 2 was detected by the following method:

[0118] Step 8) Dissolve 200 μg of water-soluble NdFeB nanoparticles in 1 mL of water, add 1 mCi99mTc and 20 μg of stannous chloride, heat at 37°C for 30 minutes, and then ultrafilter using a 30 kDa membrane and concentrate to 200 μL to achieve 99mTc labeling of the nanoparticles.

[0119] Step 9) The above drugs were injected into C57BL / 6 mice with subcutaneous melanoma on both legs through the tail vein, and then single photon emission computed tomography (SPECT-CT) was performed. Figure 5 As shown, a N52 NdFeB permanent magnet was placed on the right tumor of the mouse, and SPECT scanning was performed at 0h, 1h, 2h, 4h, 6h and 8h respectively.

[0120] See also Figure 6 As shown, Figure 6 SPECT-CT images of C57BL / 6 mice with subcutaneous melanoma injected with 99mTc-labeled water-soluble NdFeB nanoparticles. The results show that the signal of the right tumor gradually increased under magnetic targeting, especially reaching a peak at 8 hours. Therefore, water-soluble magnetic nanoparticles can achieve high tumor targeting and reduce drug distribution in non-target areas. This method provides strong data support for magnetic targeted treatment of tumors.

[0121] See also Figure 7 As shown, Figure 7 The time-dependent signal of 99mTc-labeled water-soluble NdFeB nanoparticles in two tumors in mice. The results indicate that magnetic targeting significantly enhances drug aggregation at the target tumor site, with the maximum signal intensity occurring at 8 hours (8.4%). In contrast, drug aggregation in non-magnetically targeted tumors gradually decreased, reaching only 0.5% at 8 hours, indicating the effectiveness of magnetic targeting.

[0122] Example 4 Boron neutron capture therapy of water-soluble neodymium iron borate nanoparticles on melanoma mice:

[0123] Based on Example 3, water-soluble NdFeB nanoparticles were used for boron neutron capture therapy of melanoma mice. The specific method is as follows:

[0124] Step 10) 200 μg of water-soluble NdFeB nanoparticles were injected into C57BL / 6 mice bearing subcutaneous melanoma at the back of the neck through the tail vein, and N52 NdFeB permanent magnets were placed at the tumor for 2 hours.

[0125] Step 11) 2 hours after magnetic targeting, the tumor-bearing C57BL / 6 mice were irradiated with neutron beam.

[0126] Through magnetic targeting, neodymium iron borate nanoparticles were enriched in large quantities at the tumor site of mice. Combined with boron neutron capture therapy, it significantly reduced the growth rate of melanoma and prolonged the survival time of tumor-bearing mice.

[0127] The present invention also provides an application of polymetallic borate nanoparticles or water-soluble polymetallic borate nanoparticles prepared by the above-mentioned preparation method in the precise targeted treatment of tumors, especially in combined treatments such as magnetic resonance imaging (MRI), near-infrared zone II imaging, nuclear medicine imaging, magnetic particle imaging, magnetic thermal therapy and boron neutron capture therapy, which can significantly improve the diagnostic accuracy and treatment effect of tumors.

[0128] The present invention also provides a polymetallic borate nanoparticle or a water-soluble polymetallic borate nanoparticle prepared by the above preparation method, which can be used as a carrier for tumor targeted delivery to achieve effective drug delivery, and can also be used as a synergist in magnetic thermal therapy, and has broad biomedical application prospects.

[0129] The present invention proposes a polymetallic borate nanoparticle, which is expected to become the next generation of cancer diagnosis and treatment probe platform due to its unique magnetism, versatility and good biocompatibility. Unlike traditional single metal magnetic nanomaterials, polymetallic borate nanoparticles significantly improve their magnetic properties by doping with rare earth or transition metal elements such as neodymium, yttrium or gadolinium. This doping strategy enables the material to have a higher saturation magnetization and better magnetic targeting effect, and can achieve efficient tumor enrichment at lower magnetic field strengths.

[0130] The introduction of rare earth elements enables the material to achieve near-infrared zone II imaging (NIR-II). This imaging mode has the advantages of large penetration depth and high resolution, which helps to achieve accurate positioning and diagnosis of deep tumors. In addition, the material also shows certain application value in magnetic resonance imaging (MRI) and magnetic particle imaging (MPI), and can be used to assist in the diagnosis and monitoring of tumors during treatment. At the same time, the borate ions in the material can be used for boron neutron capture therapy (BNCT). BNCT is a highly selective and low-toxic tumor treatment method. By introducing boron-containing compounds into tumor cells and then irradiating them with neutron beams, boron atoms are induced to capture neutrons and undergo nuclear reactions, releasing high linear energy alpha particles, thereby selectively killing tumor cells with less damage to normal tissues. It is particularly suitable for the treatment of certain refractory tumors.

[0131] The preparation method of the polymetallic borate nanoparticles of the present invention successfully prepares polymetallic borate nanoparticles with high magnetism and good biocompatibility by using an organic metal compound or metal salt compound precursor and an organic borate ester as raw materials and performing a thermal decomposition reaction under high temperature conditions in the presence of a small molecule with an alkyl chain. The preparation method is simple and efficient, the reaction conditions are easy to control, and the obtained nanoparticles have a monodisperse size and good morphology consistency, overcoming the problem that the existing synthesis method of polymetallic magnetic nanoparticles is not only cumbersome in process and difficult to control in reaction conditions, but also difficult to maintain consistency in size and morphology of the prepared particles.

[0132] The polymetallic borate nanoparticles of the present invention not only have multimodal imaging functions, but can also be used for multimodal tumor treatment, especially in the fields of magnetic resonance imaging, nuclear medicine imaging, magnetic particle imaging, magnetic targeted therapy and boron neutron capture therapy, and have important application value. The wide application prospects of this material in accurate tumor diagnosis and personalized treatment provide an innovative and practical solution to solve the many challenges faced by traditional magnetic nanomaterials in practical applications.

[0133] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing polymetallic borate nanoparticles, characterized in that: The following steps are involved: Step 1) dissolving an organic metal compound or metal salt compound as a precursor, a small molecule with an alkyl chain and an organic borate ester in a first solvent to form a first mixed reaction solution; Step 2) dissolving the alcohol compound in a second solvent to form a second mixed reaction solution; Step 3) Under the protection of inert gas, the first mixed reaction solution is heated to 50-150° C. at a certain stirring speed, and maintained for a period of time, and then heated to 200-350° C.; Step 4) under the protection of inert gas, the second mixed reaction solution preheated to 50-150° C. is injected into the first mixed reaction solution heated in step 3), and after the temperature stabilizes to 200-350° C., the solution is kept warm for a period of time at a certain stirring speed to form a third mixed reaction solution; Step 5) The third mixed reaction solution is naturally cooled to room temperature, and then centrifuged and purified to obtain polymetallic borate nanoparticles. The polymetallic borate nanoparticles have a size of 1 to 100 nanometers and are monodisperse.

2. The method for preparing polymetallic borate nanoparticles according to claim 1, characterized in that: The following steps are also included: Step 6) dissolving the polymetallic borate nanoparticles obtained in step 5) in a third solvent, adding biocompatible molecules, and then stirring at a certain stirring speed, heating at 40 to 100° C. or ultrasonicating for a period of time to form a fourth mixed reaction solution; Step 7) The fourth mixed solution is naturally cooled to room temperature, and then centrifuged and purified to obtain water-soluble polymetallic borate nanoparticles. The water-soluble polymetallic borate nanoparticles have a size of 1 to 100 nanometers and are monodisperse.

3. The method for preparing polymetallic borate nanoparticles according to claim 1, characterized in that: In step 1), (1) The composition and concentration of the organometallic compound or the metal salt compound are: The organometallic compound is an organic complex containing a transition metal or a rare earth metal; The metal salt compound is a salt or a hydrate thereof containing a transition metal and a rare earth metal; The transition metal and / or the rare earth metal contain one or more metal elements; The metal elements include but are not limited to iron, neodymium, manganese, copper, dysprosium, and terbium; The concentration of the organic metal compound or the inorganic metal salt compound is 0.001 to 1 mol / L; (2) The composition and concentration of the small molecule with an alkyl chain are: The small molecule with an alkyl chain is one or more of a small molecule amine with an alkyl chain, a small molecule carboxylic acid with an alkyl chain, or a small molecule alcohol with an alkyl chain, and the number of CH2 units in the alkyl chain is 4 to 24; The small molecule with an alkyl chain may also be a derivative, analog or functional equivalent compound of the small molecule with an alkyl chain listed above; The concentration of the small molecule amine with an alkyl chain, the small molecule carboxylic acid with an alkyl chain or the small molecule alcohol with an alkyl chain is 0.001 to 1 mol / L. (3) The composition and concentration of the organic borate ester are: The organic borate ester is one or more of trimethyl borate, triethyl borate, tripropyl borate, tributyl borate, tripentyl borate, trihexyl borate, triheptyl borate, trioctyl borate, trinonyl borate, and tridecyl borate, and the number of CH2 units in the alkyl chain is 1 to 24; The organic borate ester may also be a derivative, analog or functional equivalent compound of the organic borate ester listed above; The concentration of the organic borate is 0.001 to 1 mol / L; (4) The composition of the first solvent is: The first solvent is one or a mixture of 1-hexadecene, 1-tetradecene, n-octadecane, n-hexadecane, paraffin oil, mineral oil, diphenyl ether, trioctylamine, dioctyl ether, oleylamine, 1-eicosene, and 1-tetradecane; The first solvent may also be a derivative, analog or functionally equivalent compound of the solvents listed above.

4. The method for preparing polymetallic borate nanoparticles according to claim 1, characterized in that: In step 2), (1) The composition of the alcohol compound is: The alcohol compound is one or more of octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol or pentadecanol, and the number of CH2 units in the alkyl chain is 4 to 24; The alcohol compound may also be a derivative, analog or functional equivalent compound of the alcohol compounds listed above; (2) The composition of the second solvent is: The second solvent is one or a mixture of 1-hexadecene, 1-tetradecene, n-octadecane, n-hexadecane, paraffin oil, mineral oil, diphenyl ether, trioctylamine, dioctyl ether, oleylamine, 1-eicosene, and 1-tetradecane; The second solvent may also be a derivative, analog or functionally equivalent compound of the solvents listed above.

5. The method for preparing polymetallic borate nanoparticles according to claim 1, characterized in that: In step 3) and step 4), The inert gas is one or more of helium, neon, argon, xenon, krypton and nitrogen; The stirring speed of the first mixed reaction solution is 100 to 1500 rpm, and the holding time after heating to 50 to 150° C. is 5 to 60 minutes. The stirring speed of the first mixed reaction solution and the second mixed reaction solution is 100 to 1500 rpm, and the insulation time after the temperature is stabilized to 200 to 350° C. is 1 minute to 36 hours.

6. The method for preparing polymetallic borate nanoparticles according to claim 1, characterized in that: In step 5), When the third mixed reaction solution is centrifuged, the precipitant added to the third mixed reaction solution is one or a combination of ethanol, methanol, and acetone; The volume of the precipitant is 2 to 50 times the volume of the third mixed reaction solution; The method for separating the precipitate is: using the precipitant to circulate and clean and separate the precipitate once or multiple times.

7. The method for preparing polymetallic borate nanoparticles according to claim 2, characterized in that: In step 6), The third solvent is one of dichloromethane, chloroform, tetrahydrofuran, ethyl acetate, ethylene glycol, dimethyl ether, dioxane, pyridine, dimethylformamide, and dimethyl sulfoxide, or a mixture of any two thereof; The biocompatible molecule is one or more of bovine serum albumin, human serum albumin, dextran, polyethylene glycol, polyvinyl pyrrolidone, polyethylene imine, chitosan or derivatives of the above-listed biocompatible molecules; The stirring speed of the polymetallic borate nanoparticles and the biocompatible molecules in the third solvent is 100 to 1500 rpm, and the heating or ultrasonication time at 40 to 100° C. is 10 minutes to 48 hours.

8. The method for preparing polymetallic borate nanoparticles according to claim 2, characterized in that: In step 7), When the fourth mixed reaction solution is centrifuged, the precipitant added to the fourth mixed reaction solution is one or a combination of cyclohexane, n-hexane, benzene and toluene; and the volume of the precipitant is 2 to 50 times the volume of the fourth mixed reaction solution; The method for separating the precipitate is: using the precipitant to circulate and clean and separate the precipitate once or multiple times.

9. A multi-metal borate nanoparticle, characterized in that: The nanoparticles are prepared by the method for preparing the multimetal borate nanoparticles according to any one of claims 1 to 8.

10. Use of polymetallic borate nanoparticles prepared by the preparation method of polymetallic borate nanoparticles according to any one of claims 1 to 8 and / or the polymetallic borate nanoparticles according to claim 9 in magnetic resonance imaging, near-infrared zone II imaging, nuclear medicine imaging, magnetic particle imaging, magnetic thermal therapy and boron neutron capture therapy.

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