Nuclide-excited nano scintillator luminescent probe and preparation method thereof

Abstract

The invention relates to a nuclide-excited nano scintillator luminescent probe. The nano scintillator luminescent probe comprises a luminescent probe structural body and nuclide-enriched macromolecules connected with the luminescent probe structural body, and the two can be connected in advance or assembled together in vivo through electrostatic adsorption, organic covalent coupling or click chemistry / biological orthogonal reaction. According to the invention, nuclide energy is converted into optical, especially near-infrared band signals, so that a brand-new radionuclide imaging strategy is developed, and brand-new novel near-infrared luminescence without background interference is realized. The invention also provides a preparation method of the nuclide excited nano scintillator luminescent probe.

Description

Technical Field

[0001] The present invention relates to the technical field of nano-luminescent materials, and in particular to a radionuclide-excited nano-scintillator luminescent probe and a preparation method thereof. Background Art

[0002] Radionuclide imaging enables noninvasive detection of organ morphology, tissue metabolism, and lesion location, and is one of the most widely used imaging methods in clinical diagnosis and treatment. Its basic principle is to introduce a radionuclide or a labeled compound (luminescent probe) into the human body. The emitted radiation is then detected by an in vitro detection device (such as a gamma camera, SPECT, or PET), thereby obtaining images of internal organs or diseased tissues. This technology has important applications in the diagnosis of tumors, cardiovascular diseases, and neurological disorders.

[0003] Traditionally, people use bulk scintillator crystals or nanoparticles to convert the high-energy radiation emitted by radionuclides into visible light for subsequent detection. However, this method still has its limitations. For example, the uptake of these materials as imaging agents in diseased tissue is slightly different from that in normal tissue, resulting in low image contrast and difficulty in clearly distinguishing the diseased area. In addition, due to the size and detection principle limitations of traditional scintillating materials, higher-resolution in vivo radionuclide imaging is difficult to achieve. The lack of response in the near-infrared band when excited by radionuclides also limits direct imaging of luminescence from excitation of radionuclides in vivo. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a radionuclide-excited nanoscintillator luminescent probe. By converting radionuclide energy into optical signals, especially near-infrared signals, a new radionuclide imaging strategy is developed and a new type of near-infrared luminescence without background interference is achieved. The radionuclide-excited nanoscintillator luminescent probe comprises a luminescent probe structure and a radionuclide-enriched polymer, which can be pre-connected or assembled together in vivo through electrostatic adsorption, organic covalent coupling, or click chemistry / bioorthogonal reaction. The present invention also provides a method for preparing the radionuclide-excited nanoscintillator luminescent probe.

[0005] Therefore, in order to achieve the above-mentioned object, the first aspect of the present invention provides a radionuclide-excited nano-scintillator luminescent probe, wherein the nano-scintillator luminescent probe comprises a luminescent probe structure and a radionuclide-enriched polymer connected to the luminescent probe structure, wherein

[0006] The luminescent probe structure comprises a rare earth compound matrix and a plurality of rare earth luminescent points dispersed therein, wherein the rare earth compound matrix and the rare earth luminescent points are respectively selected from rare earth fluorides, alkali metal rare earth fluorides, alkaline earth metal rare earth fluorides, rare earth oxyfluorides and / or rare earth oxides; wherein the rare earth element used in the rare earth compound matrix (referred to as the first rare earth element) is selected from scandium, yttrium, lanthanum, gadolinium and / or lutetium, and the rare earth element used in the rare earth luminescent points (referred to as the second rare earth element) is selected from cerium, praseodymium, neodymium, promethium, samarium, europium, terbium, dysprosium, holmium, erbium, thulium and / or ytterbium; and

[0007] The nuclide enriching polymer is a polysaccharide or glycan adsorbed with radionuclides or a modified polysaccharide or glycan, and the radionuclides include 3 H. 18 F. 60 Co、 68 Ga, 90 Y. 99 Tc, 125 I. 131 I. 177 Lu, 192 Ir, 221 Ac, 226 Ra and / or 243 Am.

[0008] In the technical solution of the present invention, the nuclide-enriched polymer is used to provide the nuclide energy required for the luminescent probe to emit an optical signal, and the luminescent probe structure is used to convert the nuclide energy into an optical signal, especially a near-infrared signal. The alkali metal used in the rare earth compound matrix is ​​selected from lithium, sodium, potassium, rubidium, or cesium, and the alkaline earth metal used is selected from beryllium, magnesium, calcium, strontium, or barium.

[0009] Furthermore, the rare earth luminescent point is formed by doping a second rare earth element into a rare earth compound matrix, wherein the molar ratio of the second rare earth element to all rare earth elements (first rare earth element + second rare earth element) used in the luminescent probe structure is 0.1% to 90%, preferably 0.1% to 50%, and more preferably 1% to 10%.

[0010] Furthermore, the radionuclide-enriched polymer coats the luminescent probe structure; the radionuclide-enriched polymer is selected from polysaccharides or polysaccharides, such as chitosan, chitosan oligosaccharides, dextran, chitin, starch, cellulose, polysaccharide, hyaluronic acid, xanthan gum, alginate, carrageenan, cyclodextrin and / or heparin, etc.; or modified polysaccharides or polysaccharides, such as carboxymethyl chitosan, carboxymethyl cellulose and / or hydroxyethyl cellulose, etc.

[0011] Furthermore, the nuclide-enriching polymer is modified by rare earth ions to enhance its nuclide enrichment capability, and the rare earth ions used for modification include scandium ions, yttrium ions, lanthanum ions, cerium ions, praseodymium ions, neodymium ions, promethium ions, samarium ions, europium ions, gadolinium ions, terbium ions, dysprosium ions, holmium ions, erbium ions, thulium ions, ytterbium ions and / or lutetium ions.

[0012] Furthermore, the luminescent probe structure further comprises an inert shell layer covering the doped rare earth compound matrix, and the inert shell layer is composed of an undoped rare earth compound matrix or alkaline earth metal fluoride.

[0013] By coating the doped rare earth compound matrix with an inert shell, the structural stability of the luminescent probe can be improved, the biocompatibility can be enhanced, and further functional modification can be facilitated. At the same time, since the inert shell reduces surface quenching and energy loss, the luminescence intensity of the luminescent probe and the signal-to-noise ratio of the imaging can be increased, thereby improving the imaging quality.

[0014] Furthermore, the nuclide-enriched polymer and the luminescent probe structure are connected through physical electrostatic adsorption, organic covalent coupling or bioorthogonal reaction.

[0015] The physical electrostatic adsorption method involves removing the organic ligands from the surface of the luminescent probe structure and transferring it to an aqueous phase, followed by the addition of a radionuclide-enriched polymer and stirring at room temperature for 24 hours. The organic covalent coupling method involves modifying the surface of the luminescent probe structure with succinimide groups, transferring it to an aqueous phase, adding a radionuclide-enriched polymer, and stirring at room temperature for 24 hours. The bioorthogonal reaction method involves modifying the surface of the luminescent probe structure and the radionuclide-enriched polymer with corresponding click chemistry reactive groups, and linking them through the binding of the corresponding click chemistry reactive groups. These corresponding reactive groups include azide-alkyne, tetrazine-trans-cyclooctene, tetrazine-norbornene, aldehyde-hydrazide, aldehyde-aminooxy, keto-hydrazide, keto-aminooxy, thiol-maleimide, thiol-vinyl sulfone, tetrazole-olefin, diene-dienophile, azide-phosphine, etc.

[0016] Furthermore, in the luminescent probe structure, the core formed by the doped rare earth compound matrix has a size of 4 to 200 nm, and the thickness of the inert shell is 1 to 100 nm.

[0017] Furthermore, a high-boiling-point organic solvent is used in the process of forming the inner core and the inert shell of the luminescent probe structure, and the high-boiling-point organic solvent is selected from one or more of oleic acid, stearic acid, decanoic acid, octadecene, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, hexadecylamine, octadecylamine, undecenylamine, dodecenylamine, tridecenylamine, tetradecenylamine, pentadecenylamine, hexadecenylamine, heptadecenylamine, octadecenylamine and olive oil.

[0018] A second aspect of the present invention provides a method for preparing the radionuclide-excited nanoscintillator luminescent probe, the method comprising the following steps:

[0019] (1) preparing a methanol solution of a precursor required for synthesizing a luminescent probe structure, wherein the precursor is a rare earth trifluoroacetate, an alkali metal trifluoroacetate, and / or an alkaline earth metal trifluoroacetate, and dissolving the precursors in methanol, respectively, and the concentration of the obtained methanol solution is independently 0.1 to 10 mmol / ml;

[0020] (2) preparing a luminescent probe structure, wherein, under vacuum conditions, a methanol solution of the precursor is added to a high-boiling-point solvent, stirred and heated to 80-150° C., and maintained for 5-30 minutes; then, the resultant is heated to 250-330° C., and reacted under the protection of an argon atmosphere for 0.1-12 hours to obtain the luminescent probe structure;

[0021] (3) preparing the radionuclide-excited nanoscintillator luminescent probe, wherein the luminescent probe structure is connected to the radionuclide-enriched polymer through physical electrostatic adsorption, organic covalent coupling or bioorthogonal reaction.

[0022] In the above preparation method, as described above, the rare earth element (called the first rare earth element) used to form the rare earth compound matrix in the precursor is selected from scandium, yttrium, lanthanum, gadolinium and / or lutetium, the alkali metal is selected from lithium, sodium, potassium, rubidium or cesium, and the alkaline earth metal is selected from beryllium, magnesium, calcium, strontium or barium; the rare earth element (called the second rare earth element) used to form the rare earth luminescent point is selected from cerium, praseodymium, neodymium, promethium, samarium, europium, terbium, dysprosium, holmium, erbium, thulium and / or ytterbium.

[0023] The high boiling point organic solvent is selected from one or more of oleic acid, stearic acid, decanoic acid, octadecene, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, hexadecylamine, octadecylamine, undecenamine, dodecenamine, tridecenamine, tetradecenamine, pentadecenamine, hexadecenamine, heptadecenamine, octadecenamine and olive oil.

[0024] The nuclide-enriching polymer is selected from polysaccharides or polysaccharides, such as chitosan, chitosan oligosaccharides, dextran, chitin, starch, cellulose, polysaccharide, hyaluronic acid, xanthan gum, alginic acid, carrageenan, cyclodextrin and / or heparin, etc.; or modified polysaccharides or polysaccharides, such as carboxymethyl chitosan, carboxymethyl cellulose and / or hydroxyethyl cellulose, etc.

[0025] Furthermore, in step (1), the rare earth trifluoroacetate, alkali metal trifluoroacetate and alkaline earth metal trifluoroacetate are obtained by dissolving the corresponding rare earth salt or rare earth oxide, alkali metal and alkaline earth metal carbonate or oxide in trifluoroacetic acid, wherein the corresponding rare earth salt includes rare earth chloride, rare earth nitrate, rare earth acetate or rare earth acetylacetonate; the dissolution temperature is 20-150° C. and maintained for 1-48 hours, and finally a solid powder is obtained.

[0026] Furthermore, in step (2), the methanol solution of the precursor is added to the reactant obtained from the high boiling point solvent, and the total concentration of alkali metal ions, alkaline earth metal ions and rare earth ions is 0.1 to 10 mmol / ml; the reactant is heated to a reaction temperature of 250 to 330°C at a rate of 1 to 20°C / min.

[0027] Furthermore, in step (3), the luminescent probe structure is connected to the radionuclide enrichment polymer through an organic covalent coupling reaction, wherein:

[0028] The luminescent probe structure is dissolved in deionized water and a nuclide is added, and then added to a chloroform solution of succinimide ester. After thorough mixing, the chloroform solvent is evaporated to remove. Subsequently, deionized water and an aqueous solution of a nuclide-enriched polymer are added, and the mixture is stirred at room temperature for 24 hours to obtain a nuclide-excited nanoscintillator luminescent probe.

[0029] Furthermore, in step (3), the luminescent probe structure is connected to the nuclide-enriched polymer through a bioorthogonal reaction, wherein:

[0030] The luminescent probe structure is dissolved in deionized water and a nuclide is added, and then the solution is added to a chloroform solution of succinimide ester, and the chloroform solvent is evaporated after thorough mixing; deionized water and a first compound containing a click chemistry reactive group are then added, and the reaction is stirred at room temperature to obtain a luminescent probe structure modified with the click chemistry reactive group;

[0031] Adding a second compound containing a click chemistry reactive group to an aqueous solution of the nuclide-enriched polymer, stirring and reacting at room temperature to obtain a nuclide-enriched polymer modified with a click chemistry reactive group; wherein the click chemistry reactive groups contained in the first compound and the second compound can be linked through the reaction; and

[0032] The luminescent probe structure and the nuclide-enriched polymer modified with click chemical reaction groups are connected through a bioorthogonal reaction to obtain a nuclide-excited nano-scintillator luminescent probe.

[0033] The click chemistry reactive groups that can be linked by reaction include azide-alkyne, tetrazine-trans-cyclooctene, tetrazine-norbornene, aldehyde-hydrazide, aldehyde-aminooxy, keto-hydrazide, keto-aminooxy, thiol-maleimide, thiol-vinyl sulfone, tetrazole-olefin, diene-dienophile, azide-phosphine, etc.

[0034] Furthermore, in step (2), the obtained luminescent probe structure is used as a crystal nucleus, mixed in a high-boiling point organic solvent, and then a methanol solution of a rare earth trifluoroacetate or an alkaline earth metal trifluoroacetate of a first rare earth element is added, wherein the concentration of the methanol solution is 0.1 to 10 mmol / ml;

[0035] The mixture is heated to 80-150° C. with stirring and maintained for 5-30 min. Then, the mixture is heated to 250-330° C. and reacted under the protection of an argon atmosphere for 0.1-12 h to obtain a luminescent probe structure containing an inert shell.

[0036] Furthermore, in the preparation method, the wavelength of the near-infrared scintillation emission emitted by the obtained luminescent probe is adjusted by changing the type of the second rare earth element, comprising:

[0037] Thulium is used as the second rare earth element, so that the strongest emission wavelength of the luminescent probe is 1450nm;

[0038] Erbium is used as the second rare earth element, so that the strongest emission wavelength of the luminescent probe is 1548nm;

[0039] Using holmium as the second rare earth element, the strongest emission wavelength of the luminescent probe is 1180nm;

[0040] Neodymium is used as the second rare earth element, so that the strongest emission wavelength of the luminescent probe is 1070nm;

[0041] Ytterbium is used as the second rare earth element, so that the strongest emission wavelength of the luminescent probe is 996nm.

[0042] Furthermore, in the preparation method, the intensity of the near-infrared scintillation emission emitted by the luminescent probe is adjusted by changing the type and ratio of the reaction solvent, the heating rate to the reaction temperature, the reactant concentration, the reaction time, the reaction temperature and / or the doping concentration of the rare earth ion, including:

[0043] When the heating rate is 5-10°C / min, the near-infrared scintillation emission intensity increases with the increase of the heating rate;

[0044] When the heating rate is 12-18°C / min, the near-infrared scintillation emission intensity decreases with the increase of the heating rate;

[0045] When the total concentration of alkali metal ions, alkaline earth metal ions, and rare earth ions in the reactants is 0.0375-0.10 mmol / ml, the intensity of near-infrared scintillation emission increases with the increase of reactant concentration;

[0046] When the total concentration of alkali metal ions, alkaline earth metal ions, and rare earth ions in the reactants is 0.12-0.2 mmol / ml, the near-infrared scintillation emission intensity decreases with the increase of the reactant concentration;

[0047] When the reaction time is 0.25 to 10 h, the intensity of near-infrared scintillation emission increases with the increase of reaction time;

[0048] When the reaction temperature is 250-310°C, the intensity of near-infrared scintillation emission increases with the increase of reaction temperature;

[0049] When the ytterbium doping concentration is 0.1-5.0 mol%, the near-infrared scintillation emission intensity increases with the increase of the doping concentration;

[0050] When the ytterbium doping concentration is 5.5-50.0 mol%, the near-infrared scintillation emission intensity decreases with the increase of the doping concentration;

[0051] When the doping concentration of neodymium is 0.1-3.0 mol%, the intensity of near-infrared scintillation emission increases with the increase of doping concentration;

[0052] When the doping concentration of neodymium is 3.5-50.0 mol%, the intensity of near-infrared scintillation emission decreases with the increase of doping concentration;

[0053] When the erbium doping concentration is 0.1-10.0 mol%, the near-infrared scintillation emission intensity increases with the increase of the doping concentration;

[0054] When the erbium doping concentration is 10.5-50.0 mol%, the near-infrared scintillation emission intensity decreases with the increase of the doping concentration;

[0055] When the thulium doping concentration is 0.1-7.0 mol%, the near-infrared scintillation emission intensity increases with the increase of the doping concentration;

[0056] When the thulium doping concentration is 7.5-50.0 mol%, the near-infrared scintillation emission intensity decreases with the increase of the doping concentration.

[0057] When the holmium doping concentration is 0.1-7.0 mol%, the near-infrared scintillation emission intensity increases with the increase of the doping concentration;

[0058] When the doping concentration of holmium is 7.5-50.0 mol%, the intensity of near-infrared scintillation emission decreases with the increase of the doping concentration.

[0059] The doping concentration refers to the ratio of the mentioned rare earth element to the amount of all rare earth elements used in the luminescent probe structure.

[0060] The significance of the technical solution of the present invention lies in that the spatiotemporal resolution of the resulting nanoscintillator luminescence probe system is significantly improved compared to traditional radionuclide imaging structures, and its signal-to-noise ratio is also significantly improved compared to traditional laser-excited near-infrared luminescence. Therefore, the nanoscintillator luminescence probe system and the corresponding imaging method are of great significance and have broad application prospects in imaging equipment, laser material design, radioactive contamination monitoring, information encoding and storage, multi-channel biological detection, in vivo imaging and analysis, and surgical navigation. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 Schematic diagram of the basic structure of a radionuclide-excited nano-scintillator luminescent probe system prepared in one embodiment of the present invention.

[0062] Figure 2 Transmission electron micrographs of near-infrared nanocrystal luminescent probe structures of SrGdF5:Yb@CaF2, SrGdF5:Nd@CaF2, SrGdF5:Ho@CaF2, SrGdF5:Tm@CaF2 and SrGdF5:Er@CaF2 prepared in one embodiment.

[0063] Figure 3 In one embodiment, the near-infrared nanocrystal luminescent probe structures of SrGdF5:Yb@CaF2, SrGdF5:Nd@CaF2, SrGdF5:Ho@CaF2, SrGdF5:Tm@CaF2 and SrGdF5:Er@CaF2 are prepared. 18 Scintillation emission spectrum under excitation of F nuclide.

[0064] Figure 4 The adsorption of the complex of SrGdF5:Yb@CaF2 prepared in one embodiment of the present invention by connecting chitosan oligosaccharide through organic covalent coupling and bioorthogonal reaction 18 F nuclide was later 18 Near-infrared imaging image and intensity of F nuclide excitation. DETAILED DESCRIPTION

[0065] In order to better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings.

[0066] Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0067] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0068] In the description of this specification, the terms "one embodiment", "some embodiments", "embodiments", "examples", "specific examples" or "some examples" refer to the specific features, structures, materials or characteristics described in conjunction with the embodiment or example and included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and features of different embodiments or examples, unless they are mutually inconsistent.

[0069] Example 1

[0070] This embodiment provides a radionuclide-excited nano-scintillator luminescent probe, which includes a luminescent probe structure and a radionuclide-enriched polymer connected to the luminescent probe structure, wherein

[0071] The luminescent probe structure comprises a rare earth compound matrix and a plurality of rare earth luminescent points dispersed therein, wherein the rare earth compound matrix and the rare earth luminescent points are respectively selected from rare earth fluorides, alkali metal rare earth fluorides, alkaline earth metal rare earth fluorides, rare earth oxyfluorides and / or rare earth oxides; wherein the rare earth element used in the rare earth compound matrix (referred to as the first rare earth element) is selected from scandium, yttrium, lanthanum, gadolinium and / or lutetium, and the rare earth element used in the rare earth luminescent points (referred to as the second rare earth element) is selected from cerium, praseodymium, neodymium, promethium, samarium, europium, terbium, dysprosium, holmium, erbium, thulium and / or ytterbium;

[0072] The nuclide enriching polymer is a polysaccharide or glycan adsorbed with radionuclides or a modified polysaccharide or glycan, and the radionuclides include 3 H. 18 F. 60Co、 68 Ga, 90 Y. 99 Tc, 125 I. 131 I. 177 Lu, 192 Ir, 221 Ac, 226 Ra and / or 243 Am.

[0073] like Figure 1 The figure shows a basic structural diagram of a nuclide-excited nano-scintillator luminescent probe system prepared in one embodiment. In addition to comprising a rare earth compound matrix and a plurality of rare earth luminescent points dispersed therein, the luminescent probe structure is also coated with an inert shell layer on the outside of the matrix, and the inert shell layer is composed of undoped rare earth compound matrix or alkaline earth metal fluoride. In addition, the nuclide enriching polymer is a rare earth modified polysaccharide, thereby enriching the nuclide 18 F.

[0074] Example 2

[0075] This example prepares rare earth metal trifluoroacetate and alkaline earth metal trifluoroacetate precursors.

[0076] (1) Preparation of methanol solution of rare earth metal trifluoroacetate precursor

[0077] 1) Preparation of Ytterbium Trifluoroacetate: To a 100-ml three-necked round-bottom flask, 0.5 mmol of ytterbium oxide, 50 ml of trifluoroacetic acid, and 20 ml of distilled water were added sequentially. The mixture was heated to 70°C with magnetic stirring for 12 hours to obtain a solid powder. This was dissolved in 80 ml of methanol to obtain a clear, transparent ytterbium trifluoroacetate solution.

[0078] 2) Preparation of Neodymium Trifluoroacetate: To a 100-ml three-necked round-bottom flask, 0.5 mmol of neodymium oxide, 50 ml of trifluoroacetic acid, and 20 ml of distilled water were added, sequentially. The mixture was heated to 70°C with magnetic stirring for 12 hours to obtain a solid powder. This was dissolved in 80 ml of methanol to obtain a clear, transparent neodymium trifluoroacetate solution.

[0079] 3) Preparation of Holmium Trifluoroacetate: To a 100-ml three-necked round-bottom flask, 0.5 mmol of holmium oxide, 50 ml of trifluoroacetic acid, and 20 ml of distilled water were added sequentially. The mixture was heated to 70°C with magnetic stirring for 12 hours to obtain a solid powder. This was dissolved in 80 ml of methanol to obtain a clear, transparent holmium trifluoroacetate solution.

[0080] 4) Preparation of Thulium Trifluoroacetate: To a 100-ml three-necked round-bottom flask, 0.5 mmol of thulium oxide, 50 ml of trifluoroacetic acid, and 20 ml of distilled water were added sequentially. The mixture was heated to 70°C with magnetic stirring for 12 h to obtain a solid powder. This was dissolved in 80 ml of methanol to obtain a clear, transparent thulium trifluoroacetate solution.

[0081] 5) Preparation of Erbium Trifluoroacetate: To a 100-ml three-necked round-bottom flask, 0.5 mmol of erbium oxide, 50 ml of trifluoroacetic acid, and 20 ml of distilled water were added sequentially. The mixture was heated to 70°C with magnetic stirring for 12 hours to obtain a solid powder. This was dissolved in 80 ml of methanol to obtain a clear, transparent Erbium Trifluoroacetate solution.

[0082] 6) Preparation of Gd3FA: To a 100 ml three-necked round-bottom flask, 0.5 mmol of gadolinium oxide, 50 ml of trifluoroacetic acid, and 20 ml of distilled water were added sequentially. The mixture was heated to 70°C with magnetic stirring for 12 hours to obtain a solid powder. This was dissolved in 80 ml of methanol to obtain a clear Gd3FA solution.

[0083] (2) Preparation of methanol solution of alkaline earth metal trifluoroacetate precursor

[0084] 1) Preparation of strontium trifluoroacetate: Strontium carbonate was dissolved in trifluoroacetic acid and heated to 120°C with magnetic stirring for 24 hours to obtain a solid powder. This powder was dissolved in 100 ml of methanol to obtain a clear strontium trifluoroacetate solution with a final concentration of 5 mmol / ml.

[0085] 2) Preparation of calcium trifluoroacetate: Calcium carbonate was dissolved in trifluoroacetic acid and heated to 120°C with magnetic stirring for 24 hours to obtain a solid powder. This powder was then dissolved in 100 ml of methanol to obtain a clear calcium trifluoroacetate solution with a final concentration of 5 mmol / ml.

[0086] Example 3

[0087] A luminescent probe structure 1 having an inert shell layer is prepared, wherein the rare earth compound matrix contains rare earth element Gd (content 90 mol %) and rare earth element Er (doping content 10 mol %).

[0088] To a 100ml three-necked round-bottom flask, add 0.900mmol of gadolinium trifluoroacetate, 0.100mmol of erbium trifluoroacetate, and 1.00mmol of strontium trifluoroacetate, followed by 5ml of oleic acid and 5ml of octadecene. The reaction mixture was heated to 130°C under vacuum dehydration and deoxygenation with stirring for 15 minutes. Under high-purity argon, the temperature was increased at a rate of 10°C / min to 280°C and maintained for 50 minutes. After cooling, 1.00mmol of calcium trifluoroacetate was added. The reaction mixture was heated to 130°C under vacuum dehydration and deoxygenation with stirring for 15 minutes. Under high-purity argon, the temperature was increased at a rate of 10°C / min to 280°C and maintained for 50 minutes. After the reactants were cooled to room temperature, ethanol was added to precipitate the product from the solution. The supernatant was then removed by centrifugation. After repeated washing three times with anhydrous ethanol, the product was dissolved in 10 ml of cyclohexane to obtain a luminescent probe structure with good dispersion and uniformity. The luminescent probe structure was oil-soluble and had a core-shell structure with a particle size of 5 to 200 nm.

[0089] Example 4

[0090] A luminescent probe structure 2 having an inert shell layer was prepared, wherein the rare earth compound matrix contained rare earth element Gd (content 93 mol %) and rare earth element Tm (doping content 7 mol %).

[0091] To a 100ml three-necked round-bottom flask, add 0.930mmol of gadolinium trifluoroacetate, 0.070mmol of erbium trifluoroacetate, and 1.00mmol of strontium trifluoroacetate, followed by 5ml of oleic acid and 5ml of octadecene. The reaction mixture was heated to 130°C under vacuum dehydration and deoxygenation conditions with stirring for 15 minutes. Under high-purity argon, the temperature was increased at a rate of 10°C / min to 280°C and maintained for 50 minutes. After cooling, 1.00mmol of calcium trifluoroacetate was added. The reaction mixture was heated to 130°C under vacuum dehydration and deoxygenation conditions with stirring for 15 minutes. Under high-purity argon, the temperature was increased at a rate of 10°C / min to 280°C and maintained for 50 minutes. After cooling, the reaction mixture was heated to 130°C under vacuum dehydration and deoxygenation conditions with stirring for 15 minutes. Under high-purity argon, the temperature was increased at a rate of 10°C / min to 280°C and maintained for 50 minutes. After the reactants were cooled to room temperature, ethanol was added to precipitate the product from the solution. The supernatant was then removed by centrifugation. After repeated washing three times with anhydrous ethanol, the product was dissolved in 10 ml of cyclohexane to obtain a luminescent probe structure with good dispersion and uniformity. The luminescent probe structure was oil-soluble and had a core-shell structure with a particle size of 5 to 200 nm.

[0092] Example 5

[0093] A luminescent probe structure 3 with an inert shell layer was prepared, wherein the rare earth compound matrix contained rare earth element Gd (content 93 mol %) and rare earth element Ho (doping content 7 mol %).

[0094] To a 100ml three-necked round-bottom flask, add 0.930mmol of gadolinium trifluoroacetate, 0.070mmol of holmium trifluoroacetate, and 1.00mmol of strontium trifluoroacetate, followed by 5ml of oleic acid and 5ml of octadecene. The reaction mixture was heated to 130°C under vacuum dehydration and deoxygenation conditions with stirring for 15 minutes. Under high-purity argon, the temperature was increased at a rate of 10°C / min to 280°C and maintained for 50 minutes. After cooling, 1.00mmol of calcium trifluoroacetate was added. The reaction mixture was heated to 130°C under vacuum dehydration and deoxygenation conditions with stirring for 15 minutes. Under high-purity argon, the temperature was increased at a rate of 10°C / min to 280°C and maintained for 50 minutes. After the reactants were cooled to room temperature, ethanol was added to precipitate the product from the solution. The supernatant was then removed by centrifugation. After repeated washing three times with anhydrous ethanol, the product was dissolved in 10 ml of cyclohexane to obtain a luminescent probe structure with good dispersion and uniformity. The luminescent probe structure was oil-soluble and had a core-shell structure with a particle size of 5 to 200 nm.

[0095] Example 6

[0096] A luminescent probe structure 4 having an inert shell layer was prepared, wherein the rare earth compound matrix contained rare earth element Gd (content 97 mol %) and rare earth element Nd (doping content 3 mol %).

[0097] To a 100ml three-necked round-bottom flask, add 0.970mmol of gadolinium trifluoroacetate, 0.030mmol of neodymium trifluoroacetate, and 1.00mmol of strontium trifluoroacetate, followed by 5ml of oleic acid and 5ml of octadecene. The reaction mixture was heated to 130°C under vacuum dehydration and deoxygenation conditions with stirring for 15 minutes. Under high-purity argon, the temperature was increased at a rate of 10°C / min to 280°C and maintained for 50 minutes. After cooling, 1.00mmol of calcium trifluoroacetate was added. The reaction mixture was heated to 130°C under vacuum dehydration and deoxygenation conditions with stirring for 15 minutes. Under high-purity argon, the temperature was increased at a rate of 10°C / min to 280°C and maintained for 50 minutes. After the reactants were cooled to room temperature, ethanol was added to precipitate the product from the solution. The supernatant was then removed by centrifugation. After repeated washing three times with anhydrous ethanol, the product was dissolved in 10 ml of cyclohexane to obtain a luminescent probe structure with good dispersion and uniformity. The luminescent probe structure was oil-soluble and had a core-shell structure with a particle size of 5 to 200 nm.

[0098] Example 7

[0099] A luminescent probe structure 5 having an inert shell layer was prepared, wherein the rare earth compound matrix contained rare earth element Gd (content 95 mol %) and rare earth element Yb (doping content 5 mol %).

[0100] To a 100ml three-necked round-bottom flask, add 0.950mmol of gadolinium trifluoroacetate, 0.050mmol of ytterbium trifluoroacetate, and 1.00mmol of strontium trifluoroacetate, followed by 5ml of oleic acid and 5ml of octadecene. The reaction mixture was heated to 130°C under vacuum dehydration and deoxygenation with stirring for 15 minutes. Under high-purity argon, the temperature was increased at a rate of 10°C / min to 280°C and maintained for 50 minutes. After cooling, 1.00mmol of calcium trifluoroacetate was added. The reaction mixture was heated to 130°C under vacuum dehydration and deoxygenation with stirring for 15 minutes. Under high-purity argon, the temperature was increased at a rate of 10°C / min to 280°C and maintained for 50 minutes. After cooling, the reaction mixture was heated to 130°C under vacuum dehydration and deoxygenation with stirring, maintained for 15 minutes. Under high-purity argon, the temperature was increased at a rate of 10°C / min to 280°C and maintained for 50 minutes. After the reactants were cooled to room temperature, ethanol was added to precipitate the product from the solution. The supernatant was then removed by centrifugation. After repeated washing three times with anhydrous ethanol, the product was dissolved in 10 ml of cyclohexane to obtain a luminescent probe structure with good dispersion and uniformity. The luminescent probe structure was oil-soluble and had a core-shell structure with a particle size of 5 to 200 nm.

[0101] like Figure 2 , which shows transmission electron microscope photos of the near-infrared nanocrystal luminescent probe structures 1-5 prepared in Examples 3-7.

[0102] like Figure 3 As shown, it shows that the luminescent probe structures 1-5 are 18 Scintillation emission spectrum under excitation of F nuclide.

[0103] Example 8

[0104] Preparation of radionuclide-excited nanoscintillator luminescent probes.

[0105] Take 2 mL of the cyclohexane solution of the Er-doped luminescent probe structure prepared in Example 3 and add it to 2 mL of a solution of nitrosyl tetrafluoroborate in N,N-dimethylformamide. Shake thoroughly for 10 minutes, then centrifuge at 10,000 rpm for 10 minutes. Discard the supernatant, add 4 mL of a 1:1 water:ethanol solution, wash thoroughly, and centrifuge again at 10,000 rpm for 10 minutes. Discard the supernatant and dissolve the resulting solution in 1 mL of deionized water.

[0106] Take 200 μl of the above-mentioned luminescent probe structure aqueous solution and add 9 mg of radionuclide 180.3 ml of F aqueous solution emits flashes in the band of 1400-1600 nm, and the wavelength corresponding to the maximum peak is 1548 nm.

[0107] Dissolve 0.5 ml of distearoylphosphoethanolamine-polyethylene glycol-succinimide ester (DSPE-PEG-NHS) in 2 ml of chloroform, and then 18 The aqueous solution of the luminescent probe structure of F was added to the above chloroform solution, and after thorough mixing, the chloroform solvent was removed by rotary evaporation, and then 1 ml of deionized water was added to obtain an aqueous solution of rare earth luminescent nanocrystals coated with active esters.

[0108] Add the Er ion-modified chitosan oligosaccharide aqueous solution to the above rare earth luminescent nanocrystal aqueous solution coated with active ester, and stir at room temperature for 24 hours to obtain a radionuclide-excited nano-scintillator luminescent probe.

[0109] Example 9

[0110] Preparation of radionuclide-excited nanoscintillator luminescent probes.

[0111] To the aqueous solution of rare earth luminescent nanocrystals coated with active esters obtained in Example 8, (4-(6-methyl-1,2,4,5-tetrazine-3-yl)phenyl)methylamine was added, and the mixture was stirred at room temperature for 24 hours to obtain a tetrazine-modified rare earth nanocrystal complex as a luminescent probe structure. At the same time, 2,5-dioxopyrrolidin-1-yl-1-(cyclooct-4-ene-1-yloxy)-1-oxo-5,8,11,14-tetraoxa-2-azaheptadecan-17-acid was added to the Er ion-modified chitosan oligosaccharide aqueous solution, and the mixture was stirred at room temperature for 24 hours to obtain trans-cyclooctene-modified chitosan oligosaccharide as a nuclide enrichment polymer. The luminescent probe structure modified with the click chemistry reaction group and the nuclide enrichment polymer obtained above were assembled into a chitosan oligosaccharide-rare earth nanocrystal complex by a bioorthogonal reaction in vivo as a nuclide-excited nanoscintillator luminescent probe.

[0112] like Figure 4 As shown, the nano-scintillator luminescent probes formed by organic covalent coupling and bioorthogonal reaction in Examples 8-9 are 18 Imaging images and intensity of F nuclide excitation. In addition, Figure 4 The above-mentioned luminescent probe structure without chitosan oligosaccharide coupling was used as a control.

[0113] The radionuclide-excited nano-scintillator luminescent probe of the present invention has broad application prospects in imaging equipment, information coding and storage, radioactive contamination monitoring, multi-channel biological detection, in vivo imaging, radiotherapy planning and evaluation, etc.

[0114] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A radionuclide-excited nanoscintillator luminescent probe, characterized in that: The nano-scintillator luminescent probe comprises a luminescent probe structure and a nuclide-enriched polymer connected to the luminescent probe structure, wherein The luminescent probe structure comprises a rare earth compound matrix and a plurality of rare earth luminescent points dispersed therein, wherein the rare earth compound matrix and the rare earth luminescent points are respectively selected from rare earth fluorides, alkali metal rare earth fluorides, alkaline earth metal rare earth fluorides, rare earth oxyfluorides and / or rare earth oxides; wherein the first rare earth element used in the rare earth compound matrix is ​​selected from scandium, yttrium, lanthanum, gadolinium and / or lutetium, and the second rare earth element used in the rare earth luminescent points is selected from cerium, praseodymium, neodymium, promethium, samarium, europium, terbium, dysprosium, holmium, erbium, thulium and / or ytterbium; and The nuclide enriching polymer is a polysaccharide or glycan adsorbed with radionuclides or a modified polysaccharide or glycan, and the radionuclides include 3 H. 18 F. 60 Co、 68 Ga, 90 Y. 99 Tc, 125 I. 131 I. 177 Lu, 192 Ir, 221 Ac, 226 Ra and / or 243 Am.

2. The radionuclide-excited nano-scintillator luminescent probe according to claim 1, characterized in that: The rare earth luminescent point is formed by doping a second rare earth element into a rare earth compound matrix, wherein the molar ratio of the second rare earth element to all rare earth elements used in the luminescent probe structure is 0.1% to 90%.

3. The radionuclide-excited nano-scintillator luminescent probe according to claim 1, characterized in that: The radionuclide-enriched polymer coats the luminescent probe structure; the radionuclide-enriched polymer is selected from polysaccharides or polysaccharides, including chitosan, chitosan oligosaccharides, dextran, chitin, starch, cellulose, polysaccharide, hyaluronic acid, xanthan gum, alginate, carrageenan, cyclodextrin and / or heparin, etc.; or modified polysaccharides or polysaccharides, including carboxymethyl chitosan, carboxymethyl cellulose and / or hydroxyethyl cellulose.

4. The radionuclide-excited nano-scintillator luminescent probe according to any one of claims 1 to 3, characterized in that: The luminescent probe structure further comprises an inert shell layer covering the doped rare earth compound matrix, wherein the inert shell layer is composed of an undoped rare earth compound matrix or alkaline earth metal fluoride.

5. The radionuclide-excited nano-scintillator luminescent probe according to claim 4, characterized in that: In the luminescent probe structure, the core formed by the doped rare earth compound matrix has a size of 4 to 200 nm, and the thickness of the inert shell is 1 to 100 nm.

6. The method for preparing a radionuclide-excited nano-scintillator luminescent probe according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: (1) preparing a methanol solution of a precursor required for synthesizing a luminescent probe structure, wherein the precursor is a rare earth trifluoroacetate, an alkali metal trifluoroacetate, and / or an alkaline earth metal trifluoroacetate, and dissolving the precursors in methanol, respectively, and the concentration of the obtained methanol solution is independently 0.1 to 10 mmol / ml; (2) preparing a luminescent probe structure, wherein, under vacuum conditions, a methanol solution of the precursor is added to a high-boiling-point solvent, stirred and heated to 80-150° C., and maintained for 5-30 minutes; then, the resultant is heated to 250-330° C., and reacted under the protection of an argon atmosphere for 0.1-12 hours to obtain the luminescent probe structure; (3) preparing the radionuclide-excited nanoscintillator luminescent probe, wherein the luminescent probe structure is connected to the radionuclide-enriched polymer through physical electrostatic adsorption, organic covalent coupling or bioorthogonal reaction.

7. The preparation method according to claim 6, characterized in that In step (1), the rare earth trifluoroacetate, alkali metal trifluoroacetate and alkaline earth metal trifluoroacetate are obtained by dissolving the corresponding rare earth salt or rare earth oxide, alkali metal and alkaline earth metal carbonate or oxide in trifluoroacetic acid, wherein the corresponding rare earth salt includes rare earth chloride, rare earth nitrate, rare earth acetate or rare earth acetylacetonate; the dissolution temperature is 20-150° C. and maintained for 1-48 hours, and finally a solid powder is obtained.

8. The preparation method according to claim 6, characterized in that In step (2), the methanol solution of the precursor is added to the reactant obtained from the high boiling point solvent, and the total concentration of alkali metal ions, alkaline earth metal ions and rare earth ions is 0.1 to 10 mmol / ml; the reactant is heated at a rate of 1 to 20°C / min to a reaction temperature of 250 to 330°C.

9. The preparation method according to claim 6, characterized in that In step (3), the luminescent probe structure is connected to the nuclide-enriched polymer through an organic covalent coupling reaction, wherein: The luminescent probe structure is dissolved in deionized water and a nuclide is added, and then added to a chloroform solution of succinimide ester. After thorough mixing, the chloroform solvent is evaporated to remove. Subsequently, deionized water and an aqueous solution of a nuclide-enriched polymer are added, and the mixture is stirred at room temperature for 24 hours to obtain a nuclide-excited nanoscintillator luminescent probe.

10. The preparation method according to claim 6, characterized in that In step (3), the luminescent probe structure is connected to the radionuclide enrichment polymer through a bioorthogonal reaction, wherein: The luminescent probe structure is dissolved in deionized water and a nuclide is added, and then the solution is added to a chloroform solution of succinimide ester, and the chloroform solvent is evaporated after thorough mixing; deionized water and a first compound containing a click chemistry reactive group are then added, and the reaction is stirred at room temperature to obtain a luminescent probe structure modified with the click chemistry reactive group; Adding a second compound containing a click chemistry reactive group to an aqueous solution of the nuclide-enriched polymer, stirring and reacting at room temperature to obtain a nuclide-enriched polymer modified with a click chemistry reactive group; wherein the click chemistry reactive groups contained in the first compound and the second compound can be linked through the reaction; and The luminescent probe structure and the nuclide-enriched polymer modified with click chemical reaction groups are connected through a bioorthogonal reaction to obtain a nuclide-excited nano-scintillator luminescent probe.

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