Application of polydopamine modified radioactive magnetic microspheres in preparation of medicines for treating tumors

Abstract

The invention relates to an application of a polydopamine modified radioactive magnetic microsphere in preparation of a medicine for treating tumors. The medicine disclosed by the invention is a medicine for combined radiation embolism and magnetocaloric therapy treatment. A radionuclide solution and the magnetic microspheres are mixed and subjected to ultrasonic treatment, a buffer solution is added for oscillation, and radionuclide-labeled magnetic microspheres are obtained; mixing and reacting the obtained radionuclide-labeled magnetic microspheres with dopamine hydrochloride in an alkaline buffer solution, and washing to obtain the polydopamine-modified radioactive magnetic microspheres. The obtained radionuclide-labeled magnetic microspheres are uniform in particle size, can stabilize embolism tumor blood vessels, have marking stability higher than 90%, have good magnetocaloric heating capacity, and can be used for tumor embolism, radioembolism, magnetocaloric therapy and combined treatment of radioembolism and magnetocaloric therapy.

Description

Technical Field

[0001] The present invention relates to the field of medical technology, in particular to the application of radioactive magnetic microspheres modified with polydopamine in the preparation of drugs for treating tumors. Background Art

[0002] Liver cancer is a common malignant tumor that seriously threatens human health. At present, the clinical treatment of liver cancer mainly depends on the stage of development of the disease. Surgery is mainly used for early liver cancer, but the early symptoms of liver cancer are not obvious, and most people are already in the middle and late stages of the disease when they are diagnosed. Since liver cancer is mainly supplied by blood through the hepatic artery, transarterial radioembolization uses microsphere carriers to locate radionuclides in tumor lesions. Radiation irradiation promotes tumor cell apoptosis or necrosis while avoiding irradiation of normal liver tissue. It is a radiotherapy technology that can be used for unresectable liver cancer. However, some liver cancer cells may develop radiation resistance during radiotherapy, affecting the treatment effect. Therefore, the combined use of multiple treatment methods may be an effective solution.

[0003] Ablation therapy can also be used as one of the treatment options for patients with unresectable liver cancer, but the efficacy may be limited by the size and location of the tumor. Magnetic hyperthermia is a new ablation treatment method. Magnetic materials generate heat energy under an alternating magnetic field, killing tumor cells by heating up the local lesion. It has the advantages of less trauma, high safety, and fewer adverse reactions.

[0004] Therefore, there is an urgent need to provide a new method for treating liver cancer by combining radioembolization and magnetic hyperthermia therapy. Summary of the invention

[0005] To solve the above technical problems, the present invention provides the use of radioactive magnetic microspheres modified by polydopamine in the preparation of drugs for treating tumors. By constructing magnetic microspheres loaded with iron oxide as carriers and combining radionuclides, magnetic microspheres with good radiostability are obtained. On the one hand, arterial embolization enables the carrier to target the tumor blood supply artery, which can maximize the effects of radiotherapy and magnetic hyperthermia. On the other hand, the application of magnetic hyperthermia can reduce the dosage of radionuclides and reduce radiation damage to normal tissues. At the same time, hyperthermia has a sensitizing effect on radiotherapy. Therefore, radioembolism and magnetic hyperthermia can become a new method for combined treatment of liver cancer.

[0006] The present invention is achieved through the following technical solutions:

[0007] The invention uses magnetic microspheres rich in iron oxide as carriers, adsorbs radionuclides and fixes them by precipitation reaction, and then modifies the surface of the microspheres with polydopamine coating by self-polymerization reaction after water washing and purification. The prepared radionuclide-labeled magnetic microspheres have uniform particle size, can stably embolize tumor blood vessels, and the labeling stability is higher than 90%. They have good magnetic thermal heating ability and can be used for tumor embolism, radioembolism, magnetic thermal therapy, and radioembolism combined with magnetic thermal therapy.

[0008] The purpose of the present invention is to provide the use of radioactive magnetic microspheres modified with polydopamine in the preparation of drugs for treating tumors, wherein the drugs are drugs for combined radioembolism and magnetic hyperthermia therapy.

[0009] In one embodiment of the present invention, the polydopamine-modified radioactive magnetic microspheres are prepared by the following method:

[0010] The radionuclide solution and the magnetic microspheres are mixed by ultrasonication, and a buffer solution is added for shaking to obtain the magnetic microspheres labeled with the radionuclide;

[0011] The obtained radioactive nuclide labeled magnetic microspheres are mixed with dopamine hydrochloride in an alkaline buffer for reaction, and then washed to obtain polydopamine modified radioactive magnetic microspheres.

[0012] In one embodiment of the present invention, a radioactive nuclide solution (0.1-10 mCi) is diluted in pure water, magnetic microspheres (1-10 mg) are added, and the mixture is ultrasonically treated at room temperature and then shaken in a constant temperature mixer. 0.01-0.1 mL of buffer is added, and then shaken. After washing with pure water, the obtained microspheres are dispersed in a tris-hydroxymethylaminomethane hydrochloride buffer (Tris-HCl) containing dopamine hydrochloride, shaken at room temperature, and washed with pure water to obtain the final product, which is a radioactive nuclide-labeled magnetic microsphere.

[0013] In one embodiment of the present invention, the radionuclide in the radionuclide solution is selected from Lutetium-177 ( 177 Lu), Yttrium-90( 90 Y), actinium-225( 225 Ac), phosphorus-32( 32 P), palladium-109 ( 109 Pd), silver-111( 111 Ag), Samarium-153 ( 153 Sm), holmium-166 ( 166 Ho), Strontium-89( 89 Sr), Strontium-89 ( 89 Sr), terbium-149 ( 149 Tb), Bismuth-212 / 213( 212 / 213 Bi), radium-223( 223Ra), Thorium-226 / 227( 226 / 227 Th).

[0014] In one embodiment of the present invention, the buffer is selected from one or more of potassium phosphate buffer, glycine-sodium hydroxide buffer, borax-sodium hydroxide buffer, sodium carbonate-sodium hydroxide buffer and potassium chloride-sodium hydroxide buffer;

[0015] And / or, the pH value of the buffer solution is 7-14; for example, 7, 8, 9, 10, 11, 12, 13, 14.

[0016] In one embodiment of the present invention, the mass ratio of the radionuclide-labeled magnetic microspheres to the dopamine hydrochloride is 1:0.1-1:100;

[0017] And / or, the alkaline buffer is a tris(hydroxymethyl)aminomethane hydrochloride buffer.

[0018] In one embodiment of the present invention, the diameter of the polydopamine-modified radioactive magnetic microspheres is 20 μm-200 μm, for example, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, etc.

[0019] In one embodiment of the present invention, the labeling stability of the polydopamine-modified radioactive magnetic microspheres is greater than 90%. Specifically, the labeling stability of the radioactive nuclide-labeled magnetic microspheres in physiological saline and fetal bovine serum is greater than 90%.

[0020] In one embodiment of the present invention, the tumor is one or more of liver cancer, kidney cancer, lung cancer, brain cancer, uterine fibroids, prostate cancer, pancreatic neuroendocrine tumors, bladder cancer, ovarian cancer and breast cancer.

[0021] In one embodiment of the present invention, the dosage form of the drug is a dry suspension or an injection.

[0022] In one embodiment of the present invention, the magnetic field strength of the magnetocaloric is 1oe-1000oe, for example, 1oe, 10oe, 100oe, 200oe, 300oe, 400oe, 500oe, 600oe, 700oe, 800oe, 900oe, 1000oe, etc.

[0023] The radionuclide-labeled magnetic microspheres of the present invention can be used for tumor embolism, radioembolism, magnetic hyperthermia therapy and combined radioembolism and magnetic hyperthermia therapy, wherein the microspheres are delivered by catheter or implantation.

[0024] In one embodiment of the present invention, the drug further comprises one or more of pharmaceutically acceptable salts, esters, hydrates, solvates, crystalline modifications, enantiomers, stereoisomers, ethers, metabolites and prodrugs.

[0025] In one embodiment of the present invention, the pharmaceutically acceptable salt includes at least one of an inorganic acid salt and an organic acid salt; preferably, the inorganic salt includes but is not limited to at least one of sodium chloride, calcium chloride, sodium sulfate and potassium nitrate; preferably, the organic acid salt includes but is not limited to at least one of acetate, benzoate, tartrate and citrate.

[0026] In one embodiment of the present invention, the drug further comprises a pharmaceutically acceptable carrier.

[0027] In one embodiment of the present invention, the carrier is selected from one or more of a disintegrant, a diluent, a lubricant, a binder, a wetting agent, a flavoring agent, a suspending agent, a surfactant, an osmotic pressure regulator and a buffer.

[0028] In one embodiment of the present invention, the surfactant is selected from one or more of Tween 80, phospholipids, mannitol, hydroxypropyl β-cyclodextrin, and poloxamer; the osmotic pressure regulator is selected from one or more of sodium chloride, glucose, lactated Ringer's solution, glycerol, sorbitol, mannitol, and propylene glycol.

[0029] The above technical solution of the present invention has the following advantages compared with the prior art:

[0030] 1. The present invention prepares a radionuclide-labeled magnetic microsphere, which can be used for tumor embolism, radioembolism, magnetic hyperthermia therapy and radioembolism combined with magnetic hyperthermia therapy.

[0031] 2. The preparation method of the present invention is simple and produces less radioactive waste.

[0032] 3. The radionuclide-labeled magnetic microspheres prepared by the present invention have uniform particle size and can stabilize embolism.

[0033] 4. The radionuclide-labeled magnetic microspheres prepared by the present invention have a labeling stability higher than 90% and have good safety in vivo.

[0034] 5. The radionuclide-labeled magnetic microspheres prepared by the present invention have good magnetothermal conversion capability, strong penetration depth, and can perform multiple magnetothermal treatments.

[0035] 6. The radionuclide-labeled magnetic microspheres prepared by the present invention cause little trauma and quick recovery during surgical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0037] Figure 1 Characterization diagrams of the magnetic microspheres and the magnetic microspheres modified with polydopamine in the present invention; specifically: optical microscope (A), scanning electron microscope (B) and particle size statistics (C) of the magnetic microspheres (MMS); optical microscope (D), scanning electron microscope (E) and particle size statistics (F) of the magnetic microspheres modified with polydopamine (MMS@PDA);

[0038] Figure 2 The present invention 177 Lu-MMS and 177 The labeling stability of Lu-MMS@PDA in normal saline and 10% fetal bovine serum (FBS), respectively;

[0039] Figure 3 The magnetization curves (A) and the local magnified images (B) of the magnetization curves of MMS and MMS@PDA in the present invention;

[0040] Figure 4 The heating images (A) and curves (B) of MMS@PDA (5, 10, 15, 20 mg) of the present invention change with time;

[0041] Figure 5 is the relative viability of VX2 cells after different treatments in the present invention;

[0042] Figure 6 The SPECT / CT images (A) and biodistribution (B) of the present invention at 2, 7, and 14 days after embolization;

[0043] Figure 7 These are the MRI images of the tumors of rabbits on days 0, 7, and 14 after different treatments in the present invention. DETAILED DESCRIPTION

[0044] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0045] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods, and the materials, reagents, etc. used are all available from commercial sources unless otherwise specified.

[0046] The experimental instruments used in the embodiments of the present invention are as follows:

[0047] Constant temperature mixer: YY10, Shanghai Yunyan Instrument Co., Ltd.; fluorescence microscope: IX73, Olympus, Japan; scanning electron microscope: EVO18, Carl Zeiss, Germany; X-ray photoelectron spectrometer: ESCALAB Xi+, ThermoFischer, USA; multifunctional microplate reader: Varioskan Flash, Thermo Scientific, Japan; confocal microscope: Olympus FV1200, CLSM, Japan; nuclear magnetic resonance imager: SIGNAArchitect, GE, USA; SPECT / CT imaging system: SymbiaIntevo Excel, Siemens, USA.

[0048] The experimental reagents used in the examples of the present invention are as follows:

[0049] Magnetic microspheres were purchased from Suzhou Nanomicro Technology Co., Ltd.; 177 LuCl 3 The solution was purchased from Sichuan Xinke Pharmaceutical Co., Ltd.; potassium hydroxide was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; phosphoric acid was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; fetal bovine serum (FBS) was purchased from HyClone, USA; dopamine hydrochloride was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; tris-HCl buffer was purchased from Sangon Biotechnology (Shanghai) Co., Ltd.;

[0050] Experimental cells: Rabbit hepatoma cell line VX2 was preserved in the laboratory.

[0051] Experimental animals: New Zealand white rabbits were purchased from Pizhou Dongfang Breeding Co., Ltd.

[0052] Example 1 Preparation and characterization of polydopamine-modified radioactive magnetic microspheres

[0053] Will 177 LuCl 3 (1μL, 1mCi) solution was diluted in 0.5mL of pure water. 10mg of magnetic microspheres were added to the radionuclide solution, and after ultrasonic treatment, oscillated at room temperature for 10min. Then 0.02mL of K 3 PO 4 Buffer solution, shake for 1 min. Then wash with pure water to collect the microspheres 177 Lu-MMS.

[0054] Dopamine hydrochloride was dissolved in Tris-HCl buffer, and the collected microspheres were added, shaken at room temperature for 30 minutes, and then washed with pure water to obtain the radionuclide labeled magnetic microspheres. 177 Lu-MMS@PDA.

[0055] Figure 1 The optical microscope and scanning electron microscope images of magnetic microspheres (MMS) and magnetic microspheres modified with polydopamine (MMS@PDA) as well as the particle size statistics are shown. Figure 1 It can be seen that the size of the microspheres is about 30 μm, and PDA modification does not affect the morphology and size of the microspheres.

[0056] Example 2 Labeling stability

[0057] Will 177 Lu-MMS and 177 Lu-MMS@PDA was incubated with saline and 10% fetal bovine serum (FBS) at 37°C to observe its radiostability over time. The supernatant was collected at 0.5h, 2h, 4h, 8h, 24h, 96h, and 192h, and the radioactivity was counted using a γ counter. The results are shown in Figure 2 As shown, it can be seen that 177 Lu-MMS and 177 The radioactivity stability of Lu-MMS@PDA in saline solution is over 90%. 177 The radiostability of Lu-MMS@PDA in 10% FBS was 95.3±2.5%. 177 The radiostability of Lu-MMS was 73.1±1.7%, and PDA modification significantly enhanced its radiostability.

[0058] Example 3: Magnetothermal heating effect of MMS@PDA

[0059] The magnetization curves of MMS and MMS@PDA were obtained using a vibrating sample magnetometer at an AMF (alternating magnetic field) of ±30 kOe and 25 °C, as shown in Figure 3 As shown. It can be seen that both MMS and MMS@PDA exhibit superparamagnetism, while the PDA coating has no effect on the magnetism of MMS. MMS@PDA (5 mg, 10 mg, 15 mg, 20 mg) was added to a centrifuge tube with an AMF of 120 Oe and a frequency of 30 kHz. Figure 4 It can be seen that the temperature increases with the increase of microspheres, and the microspheres have good magnetothermal heating performance.

[0060] Example 4 Cytotoxicity of MMS@PDA

[0061] VX2 cells were inoculated in 96-well plates and divided into 5 groups: G1: control group, G2: MMS@PDA (500 μg / mL), G3: MMS@PDA (500 μg / mL) + AMF (120 Oe) for 10 min, G4: 177 Lu-MMS@PDA (500μg / mL, 50μCi), G5: 177 Lu-MMS@PDA (500 μg / mL, 50 μCi) + AMF (120 Oe) was used for 10 min, and the cell viability was detected by CCK-8 after 24 h of incubation. The results are as follows Figure 5 shown; through Figure 5 It can be seen that 177 The cell viability in the Lu-MMS@PDA+AMF group decreased significantly to 33.6±1.7%, proving that the combined treatment can effectively kill tumor cells.

[0062] Example 5 In vivo imaging of MMS@PDA

[0063] Orthotopic implantation of VX2 tumor in the liver of New Zealand white rabbits, intra-arterial embolization injection 177 Lu-MMS@PDA (100 mg, 1 mCi) was used for SPECT / CT imaging on the 2nd, 7th, and 14th days. The results were as follows Figure 6 As shown. Figure 6 It can be seen that 14 days after embolization, the SPECT / CT images clearly showed radioactive signals in the tumor, and no obvious signals were found in other organs. The tumor and organs were removed, and the most radioactive signals were detected in the tumor (11.7±1.4%ID / g), proving that the microspheres have good radiostability in vivo.

[0064] Example 6 Therapeutic effect of MMS@PDA

[0065] Rabbits with VX2 tumors were divided into 5 groups: G1: control group, G2: MMS@PDA (100 mg), G3: MMS@PDA (100 mg) + AMF (120 Oe) 10 min, G4: 177 Lu-MMS@PDA(100mg,1mCi),G5: 177 Lu-MMS@PDA (100 mg, 1 mCi) + AMF (120 Oe) for 10 min. The tumor size was detected by MRI on days 0, 7, and 14. The results are as follows Figure 7 As shown. Figure 7 It can be seen that 177 Lu-MMS@PDA+AMF significantly inhibited tumor growth, proving that the combined use of radioembolization and magnetic hyperthermia therapy can effectively treat liver cancer.

[0066] In summary, the radionuclide-labeled magnetic microspheres prepared in this embodiment 177 Lu-MMS@PDA can stabilize embolization in vivo, has good radiostability and magnetothermal conversion capability, and can be used to treat liver cancer by combining radioembolization with magnetic hyperthermia therapy.

[0067] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. The use of polydopamine-modified radioactive magnetic microspheres in the preparation of drugs for treating tumors, characterized in that: The medicine is a medicine used for combined radioembolization and magnetic hyperthermia therapy treatment.

2. The use according to claim 1, characterized in that: The polydopamine-modified radioactive magnetic microspheres are prepared by the following method: The radionuclide solution and the magnetic microspheres are mixed by ultrasonication, and a buffer solution is added for shaking to obtain the magnetic microspheres labeled with the radionuclide; The obtained radioactive nuclide labeled magnetic microspheres are mixed with dopamine hydrochloride in an alkaline buffer for reaction, and then washed to obtain polydopamine modified radioactive magnetic microspheres.

3. The use according to claim 2, characterized in that: The radionuclides in the radionuclide solution are selected from one or more of lutetium-177, yttrium-90, actinium-225, phosphorus-32, palladium-109, silver-111, samarium-153, holmium-166, strontium-89, strontium-89, terbium-149, bismuth-212 / 213, radium-223, and thorium-226 / 227.

4. The use according to claim 2, characterized in that: The buffer is selected from one or more of potassium phosphate buffer, glycine-sodium hydroxide buffer, borax-sodium hydroxide buffer, sodium carbonate-sodium hydroxide buffer and potassium chloride-sodium hydroxide buffer; And / or, the pH value of the buffer solution is 7-14.

5. The use according to claim 2, characterized in that: The mass ratio of the radionuclide-labeled magnetic microspheres to the dopamine hydrochloride is 1:0.1-1:100; And / or, the alkaline buffer is a tris(hydroxymethyl)aminomethane hydrochloride buffer.

6. The use according to claim 1, characterized in that: The diameter of the polydopamine-modified radioactive magnetic microspheres is 20 μm-200 μm.

7. The use according to claim 1, characterized in that: The labeling stability of the polydopamine-modified radioactive magnetic microspheres is greater than 90%.

8. The use according to claim 1, characterized in that: The tumor is one or more of liver cancer, kidney cancer, lung cancer, brain cancer, uterine fibroids, prostate cancer, pancreatic neuroendocrine tumors, bladder cancer, ovarian cancer and breast cancer.

9. The use according to claim 1, characterized in that: The dosage form of the medicine is dry suspension or injection.

10. The use according to claim 1, characterized in that: The magnetic field strength of the magnetocaloric device is 1oe-1000oe.

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