Preparation method of boron-containing embolization microspheres for boron neutron capture therapy

Abstract

The invention relates to the field of medicinal chemistry, in particular to a preparation method of boron-containing embolism microspheres for boron neutron capture therapy, which is used for solving the problems that the existing boron medicine has no tumor targeting property and is limited in treatment effect. According to the preparation method, the boron medicine is coated to form the microspheres, and the embolization microspheres containing the boron medicine are blocked at the tumor part through an intervention means, so that the preparation method has the three advantages that firstly, passive targeting is realized, and the microspheres release the boron medicine at the tumor part because the microspheres are blocked at the blood supply vessel of the tumor; controllable release of the medicine is achieved, distribution of the boron medicine in other tissues and organs is reduced, and side effects of the boron medicine are reduced; and thirdly, the microspheres can carry a chemotherapy drug or a developing agent while carrying a boron drug, so that the combination of boron neutron capture therapy and chemotherapy is realized, and the treatment effect is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of medicinal chemistry, specifically to a method for preparing boron-containing embolization microspheres for boron neutron capture therapy. Background Technology

[0002] Transcatheter arterial chemoembolization (TACE) is the mainstream treatment for hypervascular tumors (especially liver cancer). It blocks the blood supply to the tumor by embolizing microspheres and releases chemotherapy drugs locally to achieve tumor ischemia and necrosis. However, TACE has the following significant drawbacks: (1) It cannot completely kill tumor cells: Local ischemia and hypoxia of the tumor will activate vascular endothelial growth factor (VEGF), promote the formation of new blood vessels and the establishment of collateral circulation, resulting in a high tumor recurrence rate; (2) Chemotherapy drugs have great side effects: Chemotherapy drugs are distributed throughout the body, have high toxicity to normal tissues, and patients have poor tolerance.

[0003] Boron neutron capture therapy is a precision radiotherapy technique. Its principle is that after boron-containing drugs accumulate at the tumor site, they are irradiated with low-energy neutrons. The boron atoms undergo a nuclear reaction with the neutrons, releasing alpha particles that can precisely kill tumor cells with minimal damage to normal tissues. However, current boron neutron capture therapy has key problems: Commonly used boron drugs in clinical practice are administered intravenously. They lack tumor targeting and require high-dose injections to achieve boron concentrations at the tumor site that reach the therapeutic threshold, leading to boron accumulation in normal tissues and increasing the risk of side effects. Furthermore, they cannot effectively block tumor blood supply, and when used alone, the tumor can still obtain nutrients through blood vessels, thus limiting the therapeutic effect.

[0004] To address the aforementioned technical shortcomings, a solution is proposed. Summary of the Invention

[0005] In order to overcome the above-mentioned technical problems, the present invention aims to provide a method for preparing boron-containing embolization microspheres for boron neutron capture therapy, which solves the problems of existing boron drugs having no tumor targeting and limited therapeutic effects.

[0006] The objective of this invention can be achieved through the following technical solutions: In a first aspect, this application provides a method for preparing boron-containing embolization microspheres for boron neutron capture therapy, comprising the following steps: Step 1: Add the polymer material to the organic solvent and stir thoroughly until completely dissolved to form a clear and transparent polymer oil phase solution, thus obtaining a continuous phase solution; Step 2: Add the boron drug to ultrapure water and stir thoroughly until completely dissolved to form an aqueous boron drug solution, thus obtaining the internal phase solution; Step 3: Add the surfactant to ultrapure water and stir thoroughly until completely dissolved to form a surfactant solution, thus obtaining a dispersed phase solution; Step 4: The continuous phase solution and the inner phase solution are respectively connected to the microfluidic device, and the dispersed phase solution is injected into the collection cell. The inner phase solution forms a uniform droplet under the continuous phase solution. After entering the dispersed phase solution, it solidifies to form microspheres. Then, centrifuge, discard the supernatant, wash with deionized water, and vacuum dry to obtain boron-containing embolization microspheres for boron neutron capture therapy.

[0007] In a preferred embodiment of the present invention, the mass fraction of the continuous phase solution is 1-10%.

[0008] In a preferred embodiment of the present invention, the concentration of the internal phase solution is 10-100 mg / mL.

[0009] In a preferred embodiment of the present invention, the mass fraction of the dispersed phase solution is 0.5-2%.

[0010] In a preferred embodiment of the present invention, the polymer material is one of chitosan, alginate, hyaluronic acid, polylactic acid, polyvinyl alcohol, and starch.

[0011] In a preferred embodiment of the present invention, the organic solvent is one of dichloromethane, trichloromethane, dichloroethane, ethyl acetate, n-hexane, and cyclohexane.

[0012] In a preferred embodiment of the present invention, the boron drug is one of 4-boron-L-phenylalanine, sodium mercaptoundecylhydrogen dodecoborane, boric acid, and thiophene-grafted polyboron compounds.

[0013] In a preferred embodiment of the present invention, the surfactant is polyvinyl alcohol PVA-1788.

[0014] In a preferred embodiment of the present invention, the thiophene-grafted polyboron compound is prepared by the following steps: Step a1: Thiophene[3,2-b]thiophene and dichloromethane were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred for 8-10 min at a temperature of 0-5℃ and a stirring rate of 200-300 r / min. Then N-bromosuccinimide was added and the mixture was stirred for 10-15 h. After the reaction was completed, the solvent was removed by rotary evaporation of the reaction product. Then the product was purified by silica gel column chromatography using eluent A to obtain the bromografted thiophene compound. Step a2: Add the bromine-grafted thiophene compound, 2,4-dihydroxybenzaldehyde, anhydrous potassium carbonate, and chloroform to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir the reaction at 20-25°C and 200-300 r / min for 10-20 min. Then raise the temperature to 70-75°C and continue stirring for 8-10 h. After the reaction is complete, cool the reaction product to room temperature, then filter under vacuum. Wash the filtrate with distilled water 3-5 times, and then remove the solvent by rotary evaporation to obtain the aldehyde-based polythiophene compound. Step a3: Add o-carborane, n-butyllithium, and tetrahydrofuran to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir the reaction at -20℃ and a stirring rate of 200-300 r / min for 20-30 min. Then add the aldehyde polythiophene compound and continue stirring for 1-2 h. After that, raise the temperature to 40-45℃ and continue stirring for 1-2 h. After the reaction is complete, cool the reaction product to room temperature, remove the solvent by rotation, and then purify by silica gel column chromatography using eluent B to obtain the thiophene-grafted polyboron compound.

[0015] In a preferred embodiment of the present invention, the ratio of thiophene[3,2-b]thiophene, dichloromethane and N-bromosuccinimide in step a1 is 10 mmol: 40-50 mL: 10 mmol.

[0016] In a preferred embodiment of the present invention, the eluent A in step a1 is petroleum ether.

[0017] In a preferred embodiment of the present invention, the ratio of the bromine-grafted thiophene compound, 2,4-dihydroxybenzaldehyde, anhydrous potassium carbonate and chloroform in step a2 is 20 mmol: 10 mmol: 30-40 mmol: 60-70 mL.

[0018] In a preferred embodiment of the present invention, the ratio of the amount of the ortho-carborane, n-butyllithium, tetrahydrofuran and aldehyde polythiophene compound in step a3 is 10 mmol: 10 mmol: 60-70 mL: 11-13 mmol.

[0019] In a preferred embodiment of the present invention, the eluent B in step a3 is a mixture of petroleum ether and ethyl acetate in a volume ratio of 3-5:1.

[0020] Compared with the prior art, the beneficial effects of the present invention are: This invention discloses a method for preparing boron-containing embolization microspheres for boron neutron capture therapy. The method involves adding a polymeric material to an organic solvent and stirring thoroughly until completely dissolved to form a clear and transparent polymeric oil phase solution, thus obtaining a continuous phase solution. Boron is then added to ultrapure water and stirred thoroughly until completely dissolved to form a boron drug aqueous solution, thus obtaining an internal phase solution. A surfactant is added to ultrapure water and stirred thoroughly until completely dissolved to form a surfactant solution, thus obtaining a dispersed phase solution. The continuous phase solution and the internal phase solution are then connected to a microfluidic device. The dispersed phase solution is injected into a collection tank, and the internal phase solution, encapsulated by the continuous phase solution, forms uniform droplets that solidify upon entering the dispersed phase solution to form microspheres. Centrifugation and discarding of the supernatant followed by washing with deionized water and vacuum drying yielded boron-containing embolization microspheres for boron neutron capture therapy. This preparation method involves coating microspheres with boron drugs and then using interventional techniques to seal these boron-containing embolization microspheres at the tumor site. It offers three advantages: first, it achieves passive targeting, as the microspheres release boron drugs at the tumor site by sealing the tumor's blood vessels; second, it enables controlled drug release, reducing the distribution of boron drugs in other tissues and organs, thus minimizing side effects; and third, the microspheres can carry chemotherapeutic drugs or contrast agents simultaneously with the boron drugs, allowing for a combination of boron neutron capture therapy and chemotherapy, significantly improving treatment efficacy.

[0021] In the preparation of boron-containing embolization microspheres for boron neutron capture therapy, a thiophene-grafted multiboron compound was first prepared. Thiophene[3,2-b]thiophene was brominated using N-bromosuccinimide, introducing bromine atoms onto the thiophene[3,2-b]thiophene to obtain a bromine-grafted thiophene compound. The bromine atom on the bromine-grafted thiophene compound reacted with the hydroxyl group on 2,4-dihydroxybenzaldehyde to form an aldehyde-based multithiophene compound containing multiple thiophene rings and aldehyde groups. Subsequently, the aldehyde group on the aldehyde-based multithiophene compound reacted with an ortho-carborane, introducing a large number of boron atoms to obtain the thiophene-grafted multiboron compound. This thiophene-grafted multiboron compound utilizes its multiple thiophene rings to achieve excellent photosensitivity. The multiboron atom compound with excellent photosensitivity can absorb neutrons and release more high-energy α particles during treatment, resulting in a significant killing effect on tumor cells and achieving precise and efficient therapeutic effects. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1:

[0023] This embodiment describes a method for preparing boron-containing embolic microspheres for boron neutron capture therapy, comprising the following steps: Step S1: Add chitosan with a degree of deacetylation > 85% to dichloromethane and stir thoroughly until completely dissolved to form a clear and transparent polymer oil phase solution, resulting in a continuous phase solution with a mass fraction of 5%. Step S2: Add the boron drug to ultrapure water and stir thoroughly until completely dissolved to form an aqueous solution of the boron drug, obtaining an internal phase solution with a concentration of 50 mg / mL; the boron drug is 4-boron-L-phenylalanine; Step S3: Add polyvinyl alcohol PVA-1788 to ultrapure water and stir thoroughly until completely dissolved to form a surfactant solution, resulting in a dispersed phase solution with a mass fraction of 1%. Step S4: The continuous phase solution and the inner phase solution are respectively connected to the microfluidic device, the dispersed phase solution is injected into the collection cell, the inner phase solution forms a uniform droplet under the continuous phase solution, and solidifies into microspheres after entering the dispersed phase solution. After centrifugation, the supernatant is discarded, and then the microspheres are washed with deionized water and vacuum dried to obtain boron-containing embolization microspheres for boron neutron capture therapy. Example 2:

[0024] This embodiment describes a method for preparing boron-containing embolic microspheres for boron neutron capture therapy, comprising the following steps: Step S1: Add chitosan with a degree of deacetylation > 85% to dichloromethane and stir thoroughly until completely dissolved to form a clear and transparent polymer oil phase solution, resulting in a continuous phase solution with a mass fraction of 5%. Step S2: Add the boron drug to ultrapure water and stir thoroughly until completely dissolved to form an aqueous solution of the boron drug, resulting in an internal phase solution with a concentration of 50 mg / mL; the boron drug is sodium mercaptoundecylhydrogen dodecorane. Step S3: Add polyvinyl alcohol PVA-1788 to ultrapure water and stir thoroughly until completely dissolved to form a surfactant solution, resulting in a dispersed phase solution with a mass fraction of 1%. Step S4: The continuous phase solution and the inner phase solution are respectively connected to the microfluidic device, the dispersed phase solution is injected into the collection cell, the inner phase solution forms a uniform droplet under the continuous phase solution, and solidifies into microspheres after entering the dispersed phase solution. After centrifugation, the supernatant is discarded, and then the microspheres are washed with deionized water and vacuum dried to obtain boron-containing embolization microspheres for boron neutron capture therapy. Example 3:

[0025] This embodiment describes a method for preparing boron-containing embolic microspheres for boron neutron capture therapy, comprising the following steps: Step S1: Add chitosan with a degree of deacetylation > 85% to dichloromethane and stir thoroughly until completely dissolved to form a clear and transparent polymer oil phase solution, resulting in a continuous phase solution with a mass fraction of 5%. Step S2: Add the boron drug to ultrapure water and stir thoroughly until completely dissolved to form an aqueous solution of the boron drug, obtaining an internal phase solution with a concentration of 50 mg / mL; the boron drug is boric acid; Step S3: Add polyvinyl alcohol PVA-1788 to ultrapure water and stir thoroughly until completely dissolved to form a surfactant solution, resulting in a dispersed phase solution with a mass fraction of 1%. Step S4: The continuous phase solution and the inner phase solution are respectively connected to the microfluidic device, the dispersed phase solution is injected into the collection cell, the inner phase solution forms a uniform droplet under the continuous phase solution, and solidifies into microspheres after entering the dispersed phase solution. After centrifugation, the supernatant is discarded, and then the microspheres are washed with deionized water and vacuum dried to obtain boron-containing embolization microspheres for boron neutron capture therapy. Example 4:

[0026] This embodiment describes a method for preparing boron-containing embolic microspheres for boron neutron capture therapy, comprising the following steps: Step S1: 10 mmol of thiophene[3,2-b]thiophene and 40 mL of dichloromethane were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred for 8 min at 0 °C and 200 r / min. Then 10 mmol of N-bromosuccinimide was added and the mixture was stirred for 10 h. After the reaction was completed, the solvent was removed by rotary evaporation of the reaction product. Then the product was purified by silica gel column chromatography using petroleum ether to obtain the bromografted thiophene compound. Step S2: 20 mmol of bromine-grafted thiophene compound, 10 mmol of 2,4-dihydroxybenzaldehyde, 30 mmol of anhydrous potassium carbonate and 60 mL of chloroform were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 20 °C and 200 r / min for 10 min. Then the temperature was raised to 70 °C and the mixture was stirred for 8 h. After the reaction was completed, the reaction product was cooled to room temperature and then filtered under vacuum. The filtrate was washed three times with distilled water and then the solvent was removed by rotary evaporation to obtain aldehyde polythiophene compound. Step S3: 10 mmol of o-carborane, 10 mmol of n-butyllithium and 60 mL of tetrahydrofuran were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred for 20 min at -20 °C and a stirring rate of 200 r / min. Then 11 mmol of aldehyde polythiophene compound was added and the mixture was stirred for 1 h. The mixture was then heated to 40 °C and stirred for 1 h. After the reaction was completed, the reaction product was cooled to room temperature and the solvent was removed by rotation. The product was then purified by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate in a volume ratio of 3:1 to obtain the thiophene-grafted polyboron compound. Step S4: Add chitosan with a degree of deacetylation > 85% to dichloromethane and stir thoroughly until completely dissolved to form a clear and transparent polymer oil phase solution, resulting in a continuous phase solution with a mass fraction of 5%. Step S5: Add the boron drug to ultrapure water and stir thoroughly until completely dissolved to form an aqueous solution of the boron drug, resulting in an internal phase solution with a concentration of 50 mg / mL; the boron drug is a thiophene-grafted polyboron compound; Step S6: Add polyvinyl alcohol PVA-1788 to ultrapure water and stir thoroughly until completely dissolved to form a surfactant solution, resulting in a dispersed phase solution with a mass fraction of 1%. Step S7: The continuous phase solution and the inner phase solution are respectively connected to the microfluidic device, the dispersed phase solution is injected into the collection cell, the inner phase solution forms a uniform droplet under the continuous phase solution, and solidifies into microspheres after entering the dispersed phase solution. After centrifugation, the supernatant is discarded, and then the microspheres are washed with deionized water and vacuum dried to obtain boron-containing embolization microspheres for boron neutron capture therapy. Example 5:

[0027] This embodiment describes a method for preparing boron-containing embolic microspheres for boron neutron capture therapy, comprising the following steps: Step S1: 10 mmol of thiophene[3,2-b]thiophene and 45 mL of dichloromethane were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred for 9 min at 3 °C and 250 r / min. Then 10 mmol of N-bromosuccinimide was added and the mixture was stirred for 12 h. After the reaction was completed, the solvent was removed by rotary evaporation of the reaction product. Then the product was purified by silica gel column chromatography using petroleum ether to obtain the bromografted thiophene compound. Step S2: 20 mmol of bromine-grafted thiophene compound, 10 mmol of 2,4-dihydroxybenzaldehyde, 35 mmol of anhydrous potassium carbonate and 65 mL of chloroform were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 22 °C and 250 r / min for 15 min. Then the temperature was raised to 72 °C and the mixture was stirred for 9 h. After the reaction was completed, the reaction product was cooled to room temperature and then filtered under vacuum. The filtrate was washed four times with distilled water and then the solvent was removed by rotary evaporation to obtain aldehyde-based polythiophene compound. Step S3: 10 mmol of o-carborane, 10 mmol of n-butyllithium and 65 mL of tetrahydrofuran were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at -20 °C and 250 r / min for 25 min. Then 12 mmol of aldehyde polythiophene compound was added and the mixture was stirred for 1.5 h. The mixture was then heated to 42 °C and stirred for 1.5 h. After the reaction was completed, the reaction product was cooled to room temperature and the solvent was removed by rotation. The product was then purified by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate in a volume ratio of 4:1 to obtain the thiophene-grafted polyboron compound. Step S4: Add chitosan with a degree of deacetylation > 85% to dichloromethane and stir thoroughly until completely dissolved to form a clear and transparent polymer oil phase solution, resulting in a continuous phase solution with a mass fraction of 5%. Step S5: Add the boron drug to ultrapure water and stir thoroughly until completely dissolved to form an aqueous solution of the boron drug, resulting in an internal phase solution with a concentration of 50 mg / mL; the boron drug is a thiophene-grafted polyboron compound; Step S6: Add polyvinyl alcohol PVA-1788 to ultrapure water and stir thoroughly until completely dissolved to form a surfactant solution, resulting in a dispersed phase solution with a mass fraction of 1%. Step S7: The continuous phase solution and the inner phase solution are respectively connected to the microfluidic device, the dispersed phase solution is injected into the collection cell, the inner phase solution forms a uniform droplet under the continuous phase solution, and solidifies into microspheres after entering the dispersed phase solution. After centrifugation, the supernatant is discarded, and then the microspheres are washed with deionized water and vacuum dried to obtain boron-containing embolization microspheres for boron neutron capture therapy. Example 6:

[0028] This embodiment describes a method for preparing boron-containing embolic microspheres for boron neutron capture therapy, comprising the following steps: Step S1: 10 mmol of thiophene[3,2-b]thiophene and 50 mL of dichloromethane were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred for 10 min at 5 °C and 300 r / min. Then 10 mmol of N-bromosuccinimide was added and the mixture was stirred for 15 h. After the reaction was completed, the solvent was removed by rotary evaporation of the reaction product. The product was then purified by silica gel column chromatography using petroleum ether to obtain the bromografted thiophene compound. Step S2: 20 mmol of bromine-grafted thiophene compound, 10 mmol of 2,4-dihydroxybenzaldehyde, 40 mmol of anhydrous potassium carbonate and 70 mL of chloroform were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 25 °C and 300 r / min for 20 min. Then the temperature was raised to 75 °C and the mixture was stirred for 10 h. After the reaction was completed, the reaction product was cooled to room temperature and then filtered under vacuum. The filtrate was washed 5 times with distilled water and then the solvent was removed by rotary evaporation to obtain aldehyde polythiophene compound. Step S3: 10 mmol of o-carborane, 10 mmol of n-butyllithium and 70 mL of tetrahydrofuran were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at -20 °C and 300 r / min for 30 min. Then 13 mmol of aldehyde polythiophene compound was added and the mixture was stirred for 2 h. The mixture was then heated to 45 °C and stirred for 2 h. After the reaction was completed, the reaction product was cooled to room temperature and the solvent was removed by rotation. The product was then purified by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate in a volume ratio of 5:1 to obtain the thiophene-grafted polyboron compound. Step S4: Add chitosan with a degree of deacetylation > 85% to dichloromethane and stir thoroughly until completely dissolved to form a clear and transparent polymer oil phase solution, resulting in a continuous phase solution with a mass fraction of 5%. Step S5: Add the boron drug to ultrapure water and stir thoroughly until completely dissolved to form an aqueous solution of the boron drug, resulting in an internal phase solution with a concentration of 50 mg / mL; the boron drug is a thiophene-grafted polyboron compound; Step S6: Add polyvinyl alcohol PVA-1788 to ultrapure water and stir thoroughly until completely dissolved to form a surfactant solution, resulting in a dispersed phase solution with a mass fraction of 1%. Step S7: The continuous phase solution and the inner phase solution are respectively connected to the microfluidic device, the dispersed phase solution is injected into the collection cell, the inner phase solution forms a uniform droplet under the continuous phase solution, and solidifies into microspheres after entering the dispersed phase solution. After centrifugation, the supernatant is discarded, and then the microspheres are washed with deionized water and vacuum dried to obtain boron-containing embolization microspheres for boron neutron capture therapy.

[0029] Performance testing Female BALB / c mice aged 7-8 weeks and weighing 20±1g were selected. Hair was removed from the right posterior back of the mice using depilatory cream. Mice were housed under specific pathogen-free conditions. 4T1 cells in the logarithmic growth phase and in good growth condition were collected by digestion and counted. Cells were then suspended in 100μL PBS at a concentration of 5x10⁻¹⁰. 6 Four T1 cells were subcutaneously injected into the right posterior dorsal region of female BALB / c mice. Tumor volume was observed, and the tumor was counted when it reached 100 mm². 3 At that time, BALB / C tumor-bearing mice were divided into 14 groups; Group 1 was injected with 200 μL of normal saline, and the fold change in tumor volume was measured every 5 days, ending the test after 15 days; Group 2 was injected with 200 μL of the normal saline solution from Example 1 (5 mg / mL), and the fold change in tumor volume was measured every 5 days, ending the test after 15 days; Group 3 was injected with 200 μL of the normal saline solution from Example 2 (5 mg / mL), and the fold change in tumor volume was measured every 5 days, ending the test after 15 days; Group 4 was injected with 200 μL of the normal saline solution from Example 3 (5 mg / mL), and the fold change in tumor volume was measured every 5 days. The tumor volume change was measured every 5 days, and the test ended after 15 days. Group 5 was injected with 200 μL of the physiological saline solution (5 mg / mL) from Example 4, and the tumor volume change was measured every 5 days, and the test ended after 15 days. Group 6 was injected with 200 μL of the physiological saline solution (5 mg / mL) from Example 5, and the tumor volume change was measured every 5 days, and the test ended after 15 days. Group 7 was injected with 200 μL of the physiological saline solution (5 mg / mL) from Example 6, and the tumor volume change was measured every 5 days, and the test ended after 15 days. Group 8 received an injection of 200 μL of normal saline, starting at 12:00 noon daily at a rate of 60 mW / cm². 2 The tumors were irradiated with white light for 1 hour, and the fold change in tumor volume was measured every 5 days. The test ended after 15 days. Group 9 was injected with 200 μL of physiological saline solution (5 mg / mL) from Example 1, starting at 12:00 noon every day at a rate of 60 mW / cm². 2 The tumors were irradiated with white light for 1 hour, and the fold change in tumor volume was measured every 5 days. The test ended after 15 days. The third group was injected with 200 μL of physiological saline solution (5 mg / mL) as described in Example 2, starting at 12:00 noon every day at a rate of 60 mW / cm². 2 The tumors were irradiated with white light for 1 hour, and the fold change in tumor volume was measured every 5 days. The test ended after 15 days. The fourth group was injected with 200 μL of physiological saline solution (5 mg / mL) as described in Example 3, starting at 12:00 noon every day at a rate of 60 mW / cm². 2The tumors were irradiated with white light for 1 hour, and the fold change in tumor volume was measured every 5 days. The test ended after 15 days. The fifth group was injected with 200 μL of physiological saline solution (5 mg / mL) as described in Example 4, starting at 12:00 noon every day at a rate of 60 mW / cm². 2 The tumors were irradiated with white light for 1 hour, and the fold change in tumor volume was measured every 5 days. The test ended after 15 days. Group 6 was injected with 200 μL of physiological saline solution (5 mg / mL) as described in Example 5, starting at 12:00 noon every day at a rate of 60 mW / cm². 2 The tumors were irradiated with white light for 1 hour, and the fold change in tumor volume was measured every 5 days. The test ended after 15 days. Group 7 was injected with 200 μL of physiological saline solution (5 mg / mL) as described in Example 6, starting at 12:00 noon every day at a rate of 60 mW / cm². 2 The tumor was irradiated with white light for 1 hour, and the change in tumor volume was measured every 5 days. The test ended after 15 days.

[0030] The formula for calculating tumor volume V is as follows:

[0031] In the formula: L is the tumor length measured with vernier calipers; W is the tumor width measured with vernier calipers.

[0032] The test results are shown in the table below:

[0033] Referring to the data in the table above, the comparison between samples in groups 1-14 shows that boron-containing embolized microspheres used for boron neutron capture therapy have excellent anti-tumor capabilities, and the anti-tumor capability is best when the boron drug is a thiophene-grafted multi-boron compound.

[0034] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0035] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in this application, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing boron-containing embolic microspheres for boron neutron capture therapy, characterized in that, Includes the following steps: Step 1: Add the polymer material to the organic solvent and stir thoroughly until completely dissolved to form a clear and transparent polymer oil phase solution, thus obtaining a continuous phase solution; Step 2: Add the boron drug to ultrapure water and stir thoroughly until completely dissolved to form an aqueous boron drug solution, thus obtaining the internal phase solution; Step 3: Add the surfactant to ultrapure water and stir thoroughly until completely dissolved to form a surfactant solution, thus obtaining a dispersed phase solution; Step 4: The continuous phase solution and the inner phase solution are respectively connected to the microfluidic device, and the dispersed phase solution is injected into the collection cell. The inner phase solution forms a uniform droplet under the continuous phase solution. After entering the dispersed phase solution, it solidifies to form microspheres. Then, centrifuge, discard the supernatant, wash with deionized water, and vacuum dry to obtain boron-containing embolization microspheres for boron neutron capture therapy.

2. The method for preparing boron-containing embolic microspheres for boron neutron capture therapy according to claim 1, characterized in that, The mass fraction of the continuous phase solution is 1-10%; the concentration of the internal phase solution is 10-100 mg / mL; and the mass fraction of the dispersed phase solution is 0.5-2%.

3. The method for preparing boron-containing embolic microspheres for boron neutron capture therapy according to claim 1, characterized in that, The polymer material is one of chitosan, alginate, hyaluronic acid, polylactic acid, polyvinyl alcohol, and starch; the organic solvent is one of dichloromethane, chloroform, dichloroethane, ethyl acetate, n-hexane, and cyclohexane.

4. The method for preparing boron-containing embolic microspheres for boron neutron capture therapy according to claim 1, characterized in that, The boron drug is one of 4-boron-L-phenylalanine, sodium mercaptoundecylhydrogen dodecorane, boric acid, and thiophene-grafted polyboron compounds.

5. The method for preparing boron-containing embolic microspheres for boron neutron capture therapy according to claim 1, characterized in that, The surfactant is polyvinyl alcohol PVA-1788.

6. The method for preparing boron-containing embolic microspheres for boron neutron capture therapy according to claim 4, characterized in that, The thiophene-grafted polyboron compound was prepared by the following steps: Step a1: Thiophene[3,2-b]thiophene and dichloromethane were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred for 8-10 min at a temperature of 0-5℃ and a stirring rate of 200-300 r / min. Then N-bromosuccinimide was added and the mixture was stirred for 10-15 h. After the reaction was completed, the solvent was removed by rotary evaporation of the reaction product. Then the product was purified by silica gel column chromatography using eluent A to obtain the bromografted thiophene compound. Step a2: Add the bromine-grafted thiophene compound, 2,4-dihydroxybenzaldehyde, anhydrous potassium carbonate, and chloroform to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir the reaction at 20-25°C and 200-300 r / min for 10-20 min. Then raise the temperature to 70-75°C and continue stirring for 8-10 h. After the reaction is complete, cool the reaction product to room temperature, then filter under vacuum. Wash the filtrate with distilled water 3-5 times, and then remove the solvent by rotary evaporation to obtain the aldehyde-based polythiophene compound. Step a3: Add o-carborane, n-butyllithium, and tetrahydrofuran to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir the reaction at -20℃ and a stirring rate of 200-300 r / min for 20-30 min. Then add the aldehyde polythiophene compound and continue stirring for 1-2 h. After that, raise the temperature to 40-45℃ and continue stirring for 1-2 h. After the reaction is complete, cool the reaction product to room temperature, remove the solvent by rotation, and then purify by silica gel column chromatography using eluent B to obtain the thiophene-grafted polyboron compound.

7. The method for preparing boron-containing embolic microspheres for boron neutron capture therapy according to claim 6, characterized in that, In step a1, the ratio of thiophene[3,2-b]thiophene, dichloromethane, and N-bromosuccinimide is 10 mmol: 40-50 mL: 10 mmol; the eluent A is petroleum ether.

8. The method for preparing boron-containing embolic microspheres for boron neutron capture therapy according to claim 6, characterized in that, The ratio of the bromine-grafted thiophene compound, 2,4-dihydroxybenzaldehyde, anhydrous potassium carbonate, and chloroform in step a2 is 20 mmol: 10 mmol: 30-40 mmol: 60-70 mL.

9. A method for preparing boron-containing embolic microspheres for boron neutron capture therapy according to claim 8, characterized in that, The ratio of the amount of the o-carborane, n-butyllithium, tetrahydrofuran, and aldehyde polythiophene compound used in step a3 is 10 mmol: 10 mmol: 60-70 mL: 11-13 mmol; the eluent B is a mixture of petroleum ether and ethyl acetate in a volume ratio of 3-5:1.

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