A radioactive freezing microneedle and its preparation method and application

Abstract

The invention discloses a radioactive frozen microneedle and a preparation method and application thereof, wherein the preparation method comprises the following steps: mixing an aqueous phase and an oil phase, obtaining microspheres by an inverse emulsion method, and then UV curing; putting the cured microspheres into a metal nuclide solution, shaking and separating to obtain radioactive labeled microspheres; putting the radioactive labeled microspheres into a drug solution, shaking and separating to obtain drug-loaded microspheres of the labeled nuclide; mixing the drug-loaded microspheres of the labeled nuclide with a polyvinyl alcohol solution, pouring them into a microneedle mold, and freezing to obtain radioactive frozen microneedles. The present invention uses vinylphosphonic acid as a raw material for preparing phosphonic acid-rich microspheres, which have a fast nuclide labeling rate, high stability, easy raw materials, simple preparation method, and low cost; constructing radioactive ice needles, the microneedle mold melts after administration, and accurately, efficiently, low-toxicly, and evenly dispersedly treats skin diseases, thereby improving the comfort and compliance of patients during the treatment process.

Description

Technical Field

[0001] The present invention relates to the field of biomedicine, and in particular to a radioactive freezing microneedle and a preparation method and application thereof. Background Art

[0002] Therapeutic radiopharmaceuticals have been widely used in clinical practice due to their good tissue penetration, lack of drug resistance, and integrated diagnosis and treatment. According to the different methods of administration, therapeutic radiopharmaceuticals can be divided into three categories: interventional, intravenous, and transdermal. Interventional therapeutic radiopharmaceuticals mainly include: 90 Gamma-radioembolization microspheres and 125 I particles; among them, 90 Y microspheres are used to embolize the blood supply arteries of tumors through interventional means, and the radiation generated by decay kills tumor cells at close range. They are suitable for the treatment of liver cancer and liver metastasis of colorectal cancer. 125 I particles are used for implantation into tumor tissues to achieve the purpose of tumor treatment. They are suitable for the treatment of solid tumors such as prostate cancer, lung cancer, and pancreatic cancer. Intravenous radiopharmaceuticals are mainly used for the treatment of systemic or multiple lesions, including those that require tissue-specific uptake or have special retention behavior. 131 I (for thyroid cancer and hyperthyroidism) and 223 RaCl 2 (for prostate cancer bone metastasis), and specific targeted 177 Lu-DOTATATE (for neuroendocrine tumors) and 177 Lu-PSMA (for prostate cancer), etc. Transdermal radiopharmaceuticals are mainly 32 P patch (mainly suitable for skin diseases such as keloid, psoriasis, neurodermatitis and skin hemangioma). The above three types of therapeutic radiopharmaceuticals achieve targeted therapy through different administration routes and show excellent efficacy in the treatment of diseases such as tumors. However, the existing therapeutic radiopharmaceuticals each have their own indications. Therefore, unlocking new administration methods and broadening the indications of radiopharmaceutical treatment through new therapeutic radiopharmaceuticals are of great significance to the development of radiopharmaceuticals.

[0003] Microneedles are a new type of transdermal drug delivery technology. Through the microneedle array, therapeutic drugs can be delivered to the dermis through the stratum corneum quickly, simply and efficiently. It has the advantages of being painless and having few side effects. Therefore, it is widely used in the treatment of skin diseases. In addition, the matrix microneedle cluster is the most ideal delivery carrier for therapeutic radionuclides. Through the design of the mold, it can match the range of the corresponding nuclides and efficiently and evenly deliver radionuclides to skin diseased areas such as melanoma, keloids, psoriasis and neurodermatitis. Compared with traditional 32P patch, radioactive cryo-microneedles loaded with radionuclides have the following advantages: 1. It has a higher radionuclide utilization rate, which can reduce the use of radionuclides while achieving therapeutic effects, thereby reducing the toxic side effects caused by radionuclides; 2. Through efficient transdermal drug delivery, it can be combined with chemotherapy drugs to achieve effective synergistic treatment.

[0004] However, it should be noted that the construction of radioactive cryomicroneedles requires the stable labeling of radionuclides to eliminate the toxicity of normal tissues caused by the diffusion of nuclides, and at the same time, the labeling rate of nuclides needs to be increased to improve the production efficiency of the product. Therefore, it is of great significance to research and develop a radioactive cryomicroneedle with high nuclide labeling rate and high labeling stability. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a radioactive cryomicroneedle and a preparation method and application thereof. Vinylphosphonic acid is used as a phosphonic acid group raw material, and acrylic acid, N,N'methylenebisacrylamide and a photoinitiator are used as an aqueous phase, which is mixed with an oil phase to obtain microspheres and solidified. The solidified microspheres are labeled with radionuclides and loaded with drugs to prepare cryomicroneedles. The radioactive cryomicroneedles can combine the advantages of microspheres and cryomicroneedles: fast radionuclide labeling rate, high labeling stability and high radionuclide utilization rate; after drug administration, the microneedle body and the base melt, thereby improving the patient's comfort and compliance during the treatment process; at the same time, the preparation method is simple, the raw materials are easily available and the cost is low, and it is suitable for the treatment of diseases such as skin tumors.

[0006] In order to solve the above technical problems, the present invention provides a method for preparing radioactive cryomicroneedles, comprising the following steps:

[0007] S1, mixing the water phase and the oil phase, obtaining microspheres by an inverse emulsion method and then UV curing;

[0008] The aqueous phase comprises vinylphosphonic acid, acrylic acid, N,N'methylenebisacrylamide, a photoinitiator and a solvent;

[0009] S2, putting the ultraviolet-cured microspheres into a metal nuclide solution, shaking, and separating to obtain radioactive microspheres;

[0010] S3, putting the radioactive microspheres into the drug solution, shaking it, and separating the drug-loaded microspheres labeled with radionuclides;

[0011] S4, mixing the drug-loaded microspheres of the labeled nuclide with the polyvinyl alcohol solution, pouring the mixture into a microneedle mold, vacuuming the mold and freezing the mixture to obtain the radioactive frozen microneedles.

[0012] The present invention uses vinylphosphonic acid as the raw material of the phosphonic acid group, and cooperates with acrylic acid, N,N'methylenebisacrylamide, and a photoinitiator as the aqueous phase, and mixes with the oil phase to prepare a phosphonic acid-rich gel microsphere through a reverse emulsion method through free radical oxidative polymerization and solidification. The solidified microspheres are subjected to the strong chelation of the phosphonic acid group on the metal nuclide, and the metal nuclide is stably marked on the microspheres. The microspheres have a rich three-dimensional pore structure, which provides space for the loading of chemotherapy drugs. After loading the drugs, microneedles are prepared. Using vinylphosphonic acid as the raw material of the phosphonic acid group, the nuclide labeling rate is fast, the labeling stability is high, and the nuclide utilization rate is high. At the same time, the raw materials are easy to obtain, and no self-synthesis is required. The preparation method is simple and the cost is low. Construct a radioactive ice needle, and the microneedle mold melts after administration, and the skin disease is accurately, effectively, low-grade, and evenly dispersed for treatment, thereby improving the patient's comfort and compliance during the treatment process.

[0013] Further, in S1, the aqueous phase comprises, by weight, 1500-4000 parts of acrylic acid, 500-2500 parts of vinylphosphonic acid, 200-400 parts of N,N'methylenebisacrylamide, 50-100 parts of photoinitiator, 12000-13000 parts of dimethyl sulfoxide (DMSO) and 8000-9000 parts of water.

[0014] Further, in S1, the oil phase includes 100,000 parts of silicone oil and 500-4,000 parts of Span 80 by weight.

[0015] Furthermore, in S1, the volume ratio of the water phase to the oil phase is 1:(3-10).

[0016] Furthermore, in S1, the UV intensity of the UV curing is 30-200 mw / cm 2 , time is 100-600s.

[0017] Further, in S2, the metal nuclide is 177 Lu, 89 Sr. 90 Y. 166 Ho, 188 Re, 99m Tc, 68 Ga, 225 Ac or 64 Cu.

[0018] Furthermore, in S2, the solvent of the metal nuclide solution is a sodium acetate aqueous solution, a potassium acetate aqueous solution or a hydrochloric acid aqueous solution with a pH of 4-6.

[0019] Furthermore, in S3, the drug is one or more of vadimethazine (DMXAA), doxorubicin, irinotecan, epirubicin, pirarubicin, arsenic trioxide, gemcitabine, bleomycin, oxaliplatin, sorafenib, lenvatinib, curcumin, quercetin, berberine, tanshinone, astragalin, and icariin.

[0020] Furthermore, in S3, the solvent of the drug solution is water.

[0021] Furthermore, in S4, the freezing temperature is -20°C to -80°C.

[0022] Furthermore, in S4, the vacuum treatment is performed to a vacuum degree of less than 133Pa.

[0023] Furthermore, in S4, the concentration of the polyvinyl alcohol solution is 2-5wt%, the molecular weight of the polyvinyl alcohol is 89000-98000, and the solvent of the polyvinyl alcohol solution is water.

[0024] Furthermore, in S4, the material of the microneedle mold is polydimethylsiloxane.

[0025] The second aspect of the present invention provides a method for preparing radioactive cryo-microneedles according to the preparation method of the first aspect.

[0026] The third aspect of the present invention provides the use of the radioactive cryomicroneedle described in the second aspect in a product for treating skin tumor diseases.

[0027] Beneficial effects of the present invention:

[0028] The present invention uses vinylphosphonic acid as a phosphonic acid group raw material, and cooperates with acrylic acid, N,N'methylenebisacrylamide, and a photoinitiator as an aqueous phase, which is mixed with an oil phase and prepared by free radical oxidative polymerization through an inverse emulsion method to obtain gel microspheres rich in phosphonic acid and solidify. The solidified microspheres are subjected to a strong chelation effect of the phosphonic acid group on metal nuclides, and the metal nuclides are stably marked on the microspheres. The microspheres have a rich three-dimensional pore structure, which provides space for the loading of chemotherapeutic drugs. After the drugs are loaded, microneedles are prepared.

[0029] The present invention adopts vinylphosphonic acid as the raw material of the phosphonic acid group, has a fast nuclide labeling rate, high labeling stability and high nuclide utilization rate, and the raw materials are easily available and do not need to be synthesized by themselves, so the preparation method is simple and the cost is low.

[0030] The present invention constructs radioactive ice needles, and the microneedle mold melts after drug administration, thereby performing precise, effective, low-grade, and evenly dispersed treatment of skin diseases, thereby improving the comfort and compliance of patients during the treatment process. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A and B are the gel microspheres of Example 1 marked at different times and temperatures. 177 The labeling rate of Lu nuclide, C is the labeling of gel microspheres analyzed by γ counter 177 After Lu nuclide, the nuclide labeling stability in physiological saline, phosphate buffered saline (PBS) and fetal bovine serum solution (FBS);

[0033] Figure 2 A and B are the gel microspheres of comparative example 1 marked at different times and temperatures. 177 The labeling rate of Lu nuclide;

[0034] Figure 3 A and B are the drug loading rate and release rate curves of the gel microspheres loaded with Wadi Mezan in Example 3, respectively;

[0035] Figure 4 A, B and C are respectively the optical microscope photos, particle size statistics and scanning electron microscope photos of the microspheres in Example 1; D and E are respectively the non-radioactive 177 Lu microspheres and loaded non-radioactive 177 Lu and Wadi Mezan microsphere photos;

[0036] Figure 5 A and B are respectively the microneedle photos and optical microscope magnified photos obtained in Example 4; C, D, and E are scanning electron microscope photos of the microneedle obtained in Example 4;

[0037] Figure 6 A, B, and C are the tumor volume changes of the control group (NC), microsphere-microneedle radionuclide group, and microsphere-microneedle radionuclide drug-loaded group after 14 days of treatment; D is the total tumor volume change of the three groups during the 14-day treatment; E is the weight change of mice in each group during the 14-day treatment. DETAILED DESCRIPTION

[0038] The technical solution of the present invention will be described clearly and completely below in conjunction with the specific embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] This embodiment provides a method for preparing a radioactive cryomicroneedle, comprising the following steps:

[0040] S1, mixing the water phase and the oil phase, obtaining phosphonic acid microspheres by an inverse emulsion method and then UV curing;

[0041] The aqueous phase comprises vinylphosphonic acid, acrylic acid, N,N'methylenebisacrylamide, a photoinitiator and a solvent;

[0042] S2, putting the ultraviolet-cured microspheres into a metal nuclide solution, shaking, and separating to obtain radioactive labeled microspheres;

[0043] S3, putting the radioactive labeled microspheres into the drug solution, shaking, and separating the drug-loaded microspheres with labeled nuclides;

[0044] S4, mixing the drug-loaded microspheres of the labeled nuclide with the polyvinyl alcohol solution, pouring the mixture into a microneedle mold, vacuuming the mold and freezing the mixture to obtain the radioactive frozen microneedles.

[0045] This embodiment uses vinylphosphonic acid as the raw material of the phosphonic acid group, and cooperates with acrylic acid, N,N'methylenebisacrylamide, and a photoinitiator as the aqueous phase, and mixes with the oil phase to prepare phosphonic acid-rich gel microspheres through a reverse emulsion method through free radical oxidative polymerization and solidify. The solidified microspheres are subjected to the strong chelation of the phosphonic acid group on the metal nuclides, and the metal nuclides are stably marked on the microspheres. The microspheres have a rich three-dimensional pore structure, which provides space for the loading of chemotherapy drugs. After loading the drugs, microneedles are prepared. Using vinylphosphonic acid as the raw material of the phosphonic acid group, the nuclide labeling rate is fast, the labeling stability is high, and the nuclide utilization rate is high. At the same time, the raw materials are easy to obtain and do not need to be synthesized by themselves. The preparation method is simple and the cost is low. Construct a radioactive ice needle, and the microneedle mold melts after administration. The skin diseases are accurately, effectively, low-grade, and evenly dispersed for treatment, which improves the patient's comfort and compliance during the treatment process.

[0046] As an embodiment, in S1, the aqueous phase comprises, by weight, 1500-4000 parts of acrylic acid, 500-2500 parts of vinylphosphonic acid, 200-400 parts of N,N'methylenebisacrylamide, 50-100 parts of photoinitiator, 12000-13000 parts of dimethyl sulfoxide and 8000-9000 parts of water; by weight, the oil phase comprises 100000 parts of silicone oil and 500-4000 parts of Span 80; the volume ratio of the aqueous phase to the oil phase is 1:(3-10); the UV intensity of the UV curing is 30-200 mw / cm 2 , time is 100-600s.

[0047] As an embodiment, in S2, the metal nuclide is 177 Lu, 89 Sr.90 Y. 166 Ho, 188 Re, 99m Tc, 68 Ga, 225 Ac or 64 Cu; the solvent of the metal nuclide solution is a sodium acetate aqueous solution, a potassium acetate aqueous solution or a hydrochloric acid aqueous solution with a pH of 4-5.

[0048] As an embodiment, in S3, the drug is one or more of vadimethazine (DMXAA), doxorubicin, irinotecan, epirubicin, pirarubicin, arsenic trioxide, gemcitabine, bleomycin, oxaliplatin, sorafenib, lenvatinib, curcumin, quercetin, berberine, tanshinone, astragalin, and icariin; the solvent of the drug solution is water.

[0049] As an embodiment, in S4, the freezing temperature is -20°C to -80°C; the vacuum treatment is performed to a vacuum degree of <133Pa; the concentration of the polyvinyl alcohol solution is 2-5wt%, the molecular weight of the polyvinyl alcohol is 89000-98000, and the solvent of the polyvinyl alcohol solution is water.

[0050] Another embodiment provides a radioactive cryo-microneedle prepared by the preparation method described in the above embodiment.

[0051] Another embodiment provides the use of the radioactive cryomicroneedles described in the above embodiment in a product for treating skin tumor diseases.

[0052] Example 1

[0053] The present embodiment relates to a method for preparing microspheres rich in phosphonic acid groups, comprising the following steps: weighing 2500 mg of vinylphosphonic acid, 1500 mg of acrylic acid, 400 mg of NN methylenebisacrylamide, and 50 mg of a photoinitiator and dissolving them in 20 mL of a solvent (including 12 mL of DMSO and 4 mL of water) as a water phase; using 100 mL of silicone oil and Span 80 as an oil phase, wherein the mass concentration of Span 80 is 0.5 wt %; after the oil phase is fully mixed, the water phase is added during stirring, and microspheres are obtained by a reverse emulsion method and microfluidics; UV curing (UV intensity 100 mw / cm 2 , curing time 100s), centrifuging at 3000rpm for 3min to collect the microspheres; repeatedly washing with 1% SDS (sodium dodecyl sulfate) and deionized water, and collecting the cured microspheres to obtain microspheres rich in phosphonic acid groups.

[0054] Comparative Example 1

[0055] This comparative example relates to a method for preparing microspheres rich in phosphonic acid groups, using acrylamide bisphosphonate monomer as the phosphonic acid group, and the preparation method comprises the following steps:

[0056] 800 mg of pamidronate disodium and 200 mg of N-acryloyloxysuccinimide were dissolved in deionized water; the reaction solution was adjusted to pH 9 with sodium hydroxide and stirred at room temperature for 72 hours; after the reaction was completed, the final product solution was dropped into anhydrous ethanol to obtain a precipitated product, the precipitated product was collected, washed three times with ethanol, and the precipitate was dried in a vacuum oven for 2 days to obtain an acrylamide bisphosphonate monomer.

[0057] 400 mg of the prepared acrylamide bisphosphonate monomer, 1600 mg of acrylamide, 200 mg of N,N'methylene bisacrylamide, and 80 mg of photoinitiator were weighed and dissolved in 10 mL of water as the inner phase; mineral oil and 8 wt% of Span 80 were used as the outer phase; the two phases were injected into the syringe respectively, and the flow rate of the liquid in different microchannels of the syringe was adjusted by the injection pump; after the pump was started, the inner phase and the outer phase were injected into the microfluidic device respectively, and microspheres were obtained by the reverse emulsion method and microfluidics, and the cured microspheres were UV-cured, cleaned and collected to obtain microspheres rich in bisphosphonic acid groups.

[0058] Example 2

[0059] This example relates to the radionuclide labeling of the microspheres rich in phosphonic acid groups prepared in Example 1 and Comparative Example 1, comprising the following steps: taking 100 μL of the prepared microspheres rich in phosphonic acid groups, adding 100 μCi 177 Lu in 500 μL sodium acetate buffer (pH = 5.6); group labeling: some were shaken at 37°C, 800 rpm for 1 min, 5 min, 15 min, and 30 min; some were shaken at 25°C, 50°C, and 75°C, 800 rpm for 30 min, and washed with deionized water three times after labeling to remove free 177 The labeling rate was calculated by measuring the precipitate and total radioactivity with a radioactivity meter.

[0060] Labeling rate = precipitated radioactivity / total radioactivity * 100%.

[0061] At room temperature, the phosphonic acid group-rich microspheres prepared in Example 1 for labeling radionuclides were placed in 1 mL of PBS, 10% FBS and physiological saline, respectively, with three replicates for each group. The radioactivity counts of the supernatant and the precipitate were measured using a γ-radiation counter at regular intervals.

[0062] Labeling stability = (precipitate radioactivity counts - supernatant radioactivity counts) / (precipitate radioactivity counts + supernatant radioactivity counts) * 100%.

[0063] Figure 1 A and B are gel microsphere markers of Example 1 177Lu nuclide labeling rate at different time and temperature; C is the γ counter analysis gel microsphere labeling 177 After Lu nuclide was added, the nuclide labeling stability in physiological saline, phosphate buffered saline (PBS) and fetal bovine serum solution (FBS) was tested, which proved that the nuclide could quickly bind to the microspheres of Example 1, with a labeling rate of more than 90% in 1 minute, and remained stable at different temperatures and in different solutions.

[0064] Figure 2 A and B are gel microsphere markers of Comparative Example 1 177 The labeling rate of Lu nuclide at different times and temperatures shows that the binding rate of the nuclide to the microspheres of Comparative Example 1 is significantly reduced, and the nuclide labeling rate of 1 min is only 51.3%. The use of ethylene phosphonic acid as the phosphonic acid group raw material in Example 1 can greatly reduce the nuclide labeling time.

[0065] Example 3

[0066] This embodiment relates to the radionuclide labeling, drug loading and microneedle preparation of the phosphonic acid group-rich microspheres prepared in Example 1, comprising the following steps: taking 100 μL of the microspheres prepared in Example 1, adding 500 μL, 1000 μL, 1500 μL, and 2000 μL of a sodium acetate solution containing non-radioactive lutetium (pH = 5.6; lutetium content = 40 pmol / mL), respectively; oscillating for 30 min at 37° C. and 800 rpm; after labeling, centrifuging at 3000 rpm for 3 min and removing the supernatant; adding 1 mL of a wadimezan aqueous solution (1 mg / mL) and oscillating under the same conditions; taking 10 μL of the supernatant every 5 min, measuring the ultraviolet absorbance, and calculating the drug loading rate.

[0067] Drug loading rate = mass of drug loaded in microspheres / total mass of drug input * 100%;

[0068] 100 μL of the microspheres loaded with Wadi Mezan were placed in 1 mL of PBS buffer (pH = 7.4) and placed in a constant temperature oscillator (37°C; 150 rpm). 10 μL of the supernatant was taken at intervals, diluted with 1.9 mL of PBS, and then the ultraviolet absorbance was measured. The absorbance of the samples collected at different time points at 350 nm was tested using an ultraviolet spectrophotometer, and the drug release rate was calculated by the following formula.

[0069] Drug release rate = drug release mass / total drug mass contained in microspheres × 100%.

[0070] Figure 3 A and B in the middle are the drug loading rate and release rate curves of the gel microspheres loaded with Wadi Mezan, respectively. It can be seen that the drug is stably loaded on the microspheres and successfully released.

[0071] Figure 4A, B and C are respectively the optical microscope photo, particle size statistics and scanning electron microscope photo of the microspheres in Example 1; Figure 4 D and E in Example 3 contain non-radioactive 177 Lu microspheres and loaded non-radioactive 177 Lu and Wadi Mezan microspheres. It can be seen that the size of the microspheres is maintained at 20-50μm, with a porous structure, which shows that the microspheres are successfully loaded with nuclides and drugs.

[0072] Example 4

[0073] This example involves the radionuclide labeling and microneedle preparation of the microspheres rich in phosphonic acid groups prepared in Example 1, comprising the following steps: taking 100 μL of the microspheres prepared in Example 1, adding 300 μCi 177 Lu in 500 μL sodium acetate buffer (pH = 5.6); oscillate at 37°C, 800 rpm for 5 minutes; after labeling, centrifuge at 3000 rpm for 3 minutes and remove the supernatant; mix the above-mentioned radionuclide-labeled microspheres with 2wt% polyvinyl alcohol solution, pour into a microneedle mold, vacuum treat and freeze at -80°C to obtain radionuclide-loaded microsphere microneedles.

[0074] Example 5

[0075] This example involves the radionuclide labeling, drug loading and microneedle preparation of the microspheres rich in phosphonic acid groups prepared in Example 1, including the following steps: taking 100 μL of the microspheres prepared in Example 1, adding 300 μCi 177 Lu in 500 μL sodium acetate buffer (pH = 5.6); oscillate at 37 ° C, 800 rpm for 5 minutes; after labeling, centrifuge at 3000 rpm for 3 minutes, and remove the supernatant; add 1 mL of wadimeizan aqueous solution (1 mg / mL), oscillate for 30 minutes under the same conditions, centrifuge at 3000 rpm for 3 minutes, and remove the supernatant; mix the labeled radionuclide-loaded microspheres with 2% polyvinyl alcohol solution, pour them into a microneedle mold, vacuum treat and freeze to obtain drug-loaded radionuclide-loaded microsphere microneedles.

[0076] Figure 5 A and B are respectively a photo of the microneedle obtained in Example 4 and a magnified photo under an optical microscope; Figure 5 C, D, and E are scanning electron microscope photos of the microneedles obtained in Example 4, respectively. It can be seen that the microsphere microneedles were successfully prepared and the surface of the microneedles was porous.

[0077] Application Example 1

[0078] 50 μL of a concentration of 2*10 7 B16F10 cells / mL were implanted in the right hind leg of male C57BL / 6 mice. When the tumor size was about 50-100 mm 3The mice were randomly divided into three groups of five: a control group (NC), a microsphere-microneedle-loaded radionuclide group (Example 4), and a microsphere-microneedle-loaded radionuclide-loaded drug group (Example 5). The microneedles obtained in Examples 4-5 were inserted into the tumor site, and the weight and tumor volume of the mice were measured every day after treatment for 14 days.

[0079] Figure 6 The therapeutic effect of microspheres and microneedles rich in phosphonic acid groups on melanoma, Figure 6 A, B, and C in the middle are the changes in tumor volume of the control group (NC), microsphere-microneedle-loaded radionuclide group, and microsphere-microneedle-loaded radionuclide-loaded drug group after 14 days of treatment; Figure 6 Middle D shows the total tumor volume changes of the three groups during the 14-day treatment; Figure 6 Figure E shows the weight changes of mice in each group during the 14-day treatment. It can be seen that the microspheres and microneedles rich in phosphonic acid groups can significantly inhibit the growth of mouse melanoma without damaging the health of the mice, especially the microspheres and microneedles loaded with radionuclides have a better effect and have a good effect in treating melanoma.

[0080] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing radioactive cryomicroneedles, characterized in that: The steps include: S1, mixing the water phase and the oil phase, obtaining microspheres by an inverse emulsion method and then UV curing; The aqueous phase comprises, by weight, 1500-4000 parts of acrylic acid, 500-2500 parts of vinylphosphonic acid, 200-400 parts of N,N'methylenebisacrylamide, 50-100 parts of photoinitiator, 12000-13000 parts of dimethyl sulfoxide and 8000-9000 parts of water; In parts by weight, the oil phase includes 100,000 parts of silicone oil and 500-4,000 parts of Span 80; S2, putting the ultraviolet-cured microspheres into a metal radionuclide solution, shaking, and separating to obtain radioactive microspheres; S3, putting the radioactive microspheres into the drug solution, shaking it, and separating the radioactive drug-loaded microspheres; S4, mixing the radioactive drug-loaded microspheres with the polyvinyl alcohol solution, pouring the mixture into a microneedle mold, vacuuming the mold and freezing the mixture to obtain the radioactive frozen microneedles.

2. The method for preparing the radioactive cryomicroneedle according to claim 1, characterized in that: In S1, the volume ratio of the water phase to the oil phase is 1:(3-10).

3. The method for preparing the radioactive cryomicroneedle according to claim 1, characterized in that: In S1, the UV intensity of the UV curing is 30-200 mw / cm 2 , time is 100-600s.

4. The method for preparing the radioactive cryomicroneedle according to claim 1, characterized in that: In S2, the metal radionuclide is 177 Lu, 89 Sr. 90 Y. 166 Ho, 188 Re, 99m Tc, 68 Ga, 225 Ac or 64 Cu.

5. The method for preparing the radioactive cryomicroneedle according to claim 1, characterized in that: In S3, the drug is one or more of vadimethazine, doxorubicin, irinotecan, epirubicin, pirarubicin, arsenic trioxide, gemcitabine, bleomycin, oxaliplatin, sorafenib, lenvatinib, curcumin, quercetin, berberine, tanshinone, astragalin, and icariin.

6. The method for preparing the radioactive cryomicroneedle according to claim 1, characterized in that: In S4, the freezing temperature is -20°C to -80°C.

7. A radioactive cryo-microneedle prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the radioactive cryomicroneedle according to claim 7 in preparing a product for treating skin tumors.

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