A soluble microneedle transdermal drug delivery system loaded with BSH and its preparation method and application

Abstract

The present invention relates to the technical field of tumor treatment, and provides a soluble microneedle transdermal drug delivery system loaded with BSH, and a preparation method and application thereof. The soluble microneedle transdermal drug delivery system loaded with BSH of the present invention comprises a substrate and a microneedle made of hyaluronic acid, and the microneedle is loaded with a boron drug BSH. The present invention also proposes a preparation method of a soluble microneedle transdermal drug delivery system loaded with BSH by a vacuum drying method, firstly preparing a BSH solution and a HA solution, and then filling the BSH solution into the cleaned microneedle mold, and after vacuum drying and exhausting the air in the microneedle mold, injecting a NA solution into the microneedle mold for ultrasonic mixing and drying the microneedle mold, demolding, encapsulating, and sterilizing to obtain a soluble microneedle transdermal drug delivery system loaded with BSH. The present invention uses soluble microneedles loaded with BSH for application in BNCT, which increases the concentration of boron drugs enriched in tumors, reduces the dosage of boron drugs and the toxic and side effects on normal tissues, and effectively improves the efficacy of boron neutron capture therapy.

Description

Technical Field

[0001] The present invention relates to the technical field of tumor treatment, and in particular to a BSH-loaded soluble microneedle transdermal drug delivery system and a preparation method and application thereof. Background Art

[0002] Radiation therapy is a conventional technique for treating malignant tumors. It damages normal tissues while treating tumors, causing serious toxic side effects. Clinically, it is often limited by the tolerance dose of normal tissues, which makes it impossible to give the tumor a sufficient radiation dose, resulting in the failure of tumor treatment. Boron neutron capture therapy (BNCT) is a binary, cell-scale, highly targeted precision radiotherapy method. It has significant advantages over traditional radiotherapy. It has an excellent killing effect on malignant tumors such as melanoma, glioma and recurrent head and neck cancer, which helps to solve the problem of targeted radiotherapy for tumors.

[0003] Boron neutron capture therapy (BNCT) relies on non-radioactive isotopes to kill cells 10 B captures thermal neutrons and undergoes a nuclear reaction, producing alpha particles and recoil 7 Li nuclei have high linear energy transfer and certain penetration ability, but their penetration ability is limited (5-9 μm, about the diameter of a cell), so they can only kill tumor cells without damaging normal tissue cells. Boron neutron capture therapy as a binary chemotherapy is divided into two treatment processes: boron drug delivery and neutron irradiation; the first is the boron drug delivery process, by injecting a boron carrier, so that each tumor cell 10 The number of B atoms is not less than 10 9 The second is the neutron irradiation process, which causes the tumor cells to 10 B atoms absorb neutrons to produce cell killing. At present, thanks to the development of linear accelerator neutron sources, neutron irradiation technology has been effectively solved, so the current limitations of boron neutron capture therapy are mainly concentrated on the boron drug delivery process. Therefore, in order to ensure the therapeutic effect of boron neutron capture therapy, efforts need to be made on the boron drug delivery process of BNCT treatment.

[0004] In order to ensure the best therapeutic effect of BNCT, the boron carrier needs to meet the following requirements: (1) 10 The content of B is not less than 20μg / g, that is, each tumor cell contains at least 10 9 indivual 10B atoms; (2) the ratio of boron concentration in tumor tissue to normal tissue (T / N) and the ratio of boron concentration in tumor tissue to blood (T / B) are both greater than 3; (3) they can be retained in tumor cells for a long time and can be cleared from blood and normal tissues at a relatively fast rate; (4) they have low intrinsic toxicity and are used to increase the maximum tolerated dose of boron carriers.

[0005] At present, boron carriers have developed to the second generation. The first generation of boron carriers are borax, boric acid and their derivatives. Due to their lack of tumor specificity, their therapeutic effects are not ideal when used in BNCT treatment and they are prone to serious side effects. The second generation of boron carriers uses 4-dihydroxyboryl-L-phenylalanine (BPA) and sodium 11-hydrogen mercapto-12-boronide (BSH). BPA and BSH are currently the only drugs clinically used in the BNCT process, but BPA and BSH still have certain shortcomings. Although BPA can selectively accumulate in tumors through tumor-rich amino acid transporters such as LAT1, it is easily excreted by tumor cells due to the anti-transport mechanism, and the retention time is short. In addition, BPA has poor water solubility and low boron content. BSH has the problem of poor tumor specificity. Therefore, in order to solve the problems existing in the application of BPA and BSH in BNCT, researchers are currently committed to developing the third-generation boron carriers including boron-containing small molecules (amino acid derivatives, porphyrin derivatives, etc.), boron-containing biomacromolecules (specific ligands, monoclonal antibodies, etc.) and boron-containing nanodrugs (liposomes, boron carbide nanomaterials, boron nitride nanomaterials, etc.).

[0006] In clinical practice, BSH is applied in boron neutron capture therapy by intravenous injection. Since the amount of boron required for boron neutron capture therapy is relatively high, the BSH dose required for clinical application in BNCT is 100 mg / kg. This requires neutron irradiation while dripping during the BNCT process, which is very inconvenient. In addition, after intravenous drip, the drug is distributed throughout the body, which will increase its toxic side effects on normal tissues. Therefore, transdermal administration can be used instead of intravenous injection.

[0007] Transdermal drug delivery can avoid the first-pass effect due to its unique delivery method, and has the characteristics of preventing gastrointestinal side effects and improving patient compliance. However, traditional transdermal drug delivery uses patch preparations. Due to the barrier effect of the skin stratum corneum, the drug has a low transdermal rate and low permeability during transdermal absorption. Therefore, in order to transport sufficient boron drugs into tumor cells during BNCT, it is urgent to improve the transdermal drug delivery method to increase the enrichment of BSH in tumor cells, improve the effect of boron neutron capture therapy, and promote the development of boron neutron capture therapy. Summary of the invention

[0008] In order to solve the problem of delivering a sufficient amount of BSH into tumor cells, the present invention proposes a soluble microneedle transdermal drug delivery system loaded with BSH, as well as a preparation method and application thereof. By loading the boron drug BSH into soluble microneedles and replacing traditional intravenous drip with transdermal drug delivery, the enrichment degree of the boron drug BSH in the tumor is increased while the injection dose of the boron drug is reduced, the toxic side effects of the boron drug on normal tissues are reduced, and the deficiency of poor tumor specificity of BSH is solved. In addition, transdermal drug delivery significantly increases the concentration of boron in the tumor, effectively improving the effect of boron neutron capture therapy.

[0009] The present invention specifically adopts the following technical solutions:

[0010] A soluble microneedle transdermal drug delivery system loaded with BSH comprises a substrate and microneedles distributed in an array on the substrate. Both the microneedles and the substrate are made of hyaluronic acid. The microneedles are arranged in a conical structure and are loaded with boron drug BSH.

[0011] Preferably, the bottom diameter of the microneedle is not less than 300 μm, and the length of the microneedle is 500-1000 μm.

[0012] The method for preparing the above-mentioned soluble microneedle transdermal drug delivery system loaded with BSH is based on a vacuum drying method to prepare the soluble microneedle transdermal drug delivery system loaded with BSH, and comprises the following steps:

[0013] Step 1, dissolving sodium undecahydromercaptododecaboride powder in water to prepare a BSH solution, and then dissolving hyaluronic acid powder in water to prepare a HA solution;

[0014] Step 2, preparing a microneedle mold, ultrasonically cleaning the microneedle mold, injecting a BSH solution into the microneedle mold, so that the BSH solution fills the microneedle mold, placing the microneedle mold in a vacuum drying oven, and vacuuming to remove bubbles in the microneedle mold and exhaust the air in the microneedle mold;

[0015] Step 3, taking the microneedle mold out of the vacuum drying oven, removing the deionized water in the microneedle mold, pouring the HA solution into the microneedle mold and ultrasonically mixing, placing the microneedle model in an air drying oven again, drying it in a vacuum environment, taking out the microneedle model, peeling it off and demolding it to obtain a soluble microneedle transdermal drug delivery system loaded with BSH;

[0016] Step 4, encapsulating and irradiating the soluble microneedle transdermal drug delivery system loaded with BSH.

[0017] Preferably, in step 1, the concentration of the BSH solution is 3-50 mg / mL, and the mass fraction of the HA solution is 20%.

[0018] Preferably, in step 3, the temperature of the air drying oven is set to 42° C. during the drying process, and the drying time is set to 12 hours.

[0019] Application of the above-mentioned BSH-loaded soluble microneedle transdermal drug delivery system in boron neutron capture therapy.

[0020] Preferably, after administration using a soluble microneedle transdermal drug delivery system loaded with BSH, BSH is enriched in the tumor tissue, and the boron concentration in the tumor tissue is not less than 20 ppm.

[0021] Preferably, after administration using a soluble microneedle transdermal drug delivery system loaded with BSH, the boron concentration ratio in tumor tissue to normal tissue is not less than 3:1, and the boron concentration ratio in tumor tissue to blood is not less than 3:1.

[0022] The present invention has the following beneficial effects:

[0023] The present invention uses hyaluronic acid as a base material to prepare a soluble microneedle transdermal drug delivery system loaded with boron drug BSH. In the BNCT process, soluble microneedles are used to replace intravenous drip injection of boron drugs, avoiding the inconvenience of neutron irradiation while dripping boron drugs during BNCT treatment. At the same time, the microneedles in the soluble microneedle transdermal drug delivery system of the present invention can dissolve in the skin and release drugs, and will not cause damage to the human body even if they break in the skin. There are fewer residues and a low risk of biological contamination. Compared with coated microneedles and hollow microneedles, the drug loading is higher and safer. Hyaluronic acid is used as a base material to quickly dissolve in tissue fluid and in vivo, so that the soluble microneedle transdermal drug delivery system has more excellent biocompatibility, high viscoelasticity, plasticity and permeability.

[0024] The present invention uses soluble microneedles loaded with BSH, which has strong tumor specificity and avoids the toxic side effects of drugs on normal tissues throughout the body, reduces the pain of patients during treatment, and improves the compliance of patients during treatment.

[0025] The present invention uses soluble microneedles loaded with BSH to increase the concentration of boron drugs enriched in tumors, effectively solve the problem of insufficient boron delivery inside tumor cells, and concentrate the boron drugs in tumor tissues for a long time, which not only prolongs the action time of the boron drugs, but also reduces the dosage and toxic side effects of the boron drugs, effectively improving the efficacy of boron neutron capture therapy, especially in the treatment of superficial tumors, and providing a new drug administration method for BNCT treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the SEM image of the soluble microneedle transdermal drug delivery system.

[0027] Figure 2 This is the displacement-stress analysis diagram of the microneedle.

[0028] Figure 3 This is a linear relationship diagram between the boron loading amount and BSH concentration in the soluble microneedles.

[0029] Figure 4 This is a statistical chart of boron concentrations in various parts of mice 2.5 hours after transdermal administration.

[0030] Figure 5 This is the tumor inhibition curve of mice. DETAILED DESCRIPTION

[0031] The present invention provides a BSH-loaded soluble microneedle transdermal drug delivery system and its preparation method and application. In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0032] Example 1

[0033] This embodiment provides a soluble microneedle transdermal drug delivery system loaded with BSH, including a substrate and microneedles distributed in an array on the substrate, the microneedles and the substrate are both made of hyaluronic acid, the microneedles are set to a cone structure, and the boron drug BSH is loaded inside. In this embodiment, the bottom diameter of the microneedle is set to 357μm and the length is set to 787μm.

[0034] Example 2

[0035] This example provides a method for preparing the soluble microneedle transdermal drug delivery system in Example 1. The soluble microneedle transdermal drug delivery system loaded with BSH is prepared based on a vacuum drying method, which specifically includes the following steps:

[0036] Step 1, dissolving sodium undecahydromercaptodecaboride powder in water to prepare a BSH solution with a concentration of 23 mg / mL, and then dissolving hyaluronic acid powder in water to prepare a HA solution with a mass fraction of 20%.

[0037] Step 2, using a laser micromachining device with a specific wavelength to perform laser micromachining on a designated mold to prepare a microneedle mold. Using a laser micromachining device to make a microneedle mold is a prior art in this field. The prepared microneedle mold is ultrasonically cleaned. After cleaning for 5 minutes, the BSH solution is injected into the microneedle mold. After the BSH solution fills the microneedle mold, the microneedle mold is placed in a vacuum drying oven, and the vacuum pump of the vacuum drying oven is turned on. When the pointer of the vacuum drying oven indicates -1, the vacuum pump of the vacuum drying oven is turned off and vacuuming is stopped. At this time, the microneedle mold is in a vacuum environment. Vacuuming is performed to remove bubbles in the microneedle mold. After 10 minutes, all the air in the microneedle mold is discharged.

[0038] Step 3, take the microneedle mold out of the vacuum drying oven, remove the deionized water in the microneedle mold, pour the HA solution into the microneedle mold and ultrasonically mix for 5 minutes, then place the microneedle model in an air drying oven again, set the temperature of the air drying oven to 42°C, dry the microneedle model in a vacuum environment for 12 hours, take out the microneedle model, peel it off and demold it to obtain a soluble microneedle loaded with BSH.

[0039] Step 4, after encapsulating and irradiating the soluble microneedle transdermal drug delivery system loaded with BSH, the soluble microneedle transdermal drug delivery system loaded with BSH is observed using a scanning electron microscope, such as Figure 1 As shown, the prepared soluble microneedle transdermal drug delivery system was characterized.

[0040] Example 3

[0041] In this example, mice were used as research subjects, and the soluble microneedle transdermal drug delivery system loaded with BSH prepared in Example 2 was tested for microneedle mechanical strength.

[0042] Since the microneedles in the soluble microneedle transdermal drug delivery system prepared in Example 2 are distributed in an array and have uniformity and integrity, the microneedles can dissolve in the interstitial fluid of the mouse tissue after penetrating the mouse skin. In order to detect the mechanical strength of the microneedles in the soluble microneedle transdermal drug delivery system, the stress values ​​of the microneedles at different penetration depths were detected by inductively coupled plasma mass spectrometry ICP-MS, and the relationship between the depth of microneedle penetration into the skin and the stress of the microneedle was obtained, as shown in FIG. Figure 2 As shown by Figure 2 It can be seen that the stress on each microneedle in the soluble microneedle transdermal drug delivery system exceeds 0.03N, and can penetrate the mouse skin. In order to better measure the penetrability of the mouse skin with the differential microneedle, after the microneedle was used to perform transdermal treatment on the mouse back skin, the cells in the mouse back skin were stained with trypan blue and observed, which further verified that the microneedles in the soluble microneedle transdermal drug delivery system loaded with BSH can effectively penetrate the mouse skin. The microneedles in this embodiment have good penetrability.

[0043] Example 4

[0044] In this example, mice were used as the research subjects to study the enrichment degree of BSH in tumors after transdermal administration of the soluble microneedle transdermal drug delivery system prepared in Example 2.

[0045] The fluorescent dye Cy5.5 was used as a model drug instead of the BSH solution. The fluorescent dye Cy5.5 was loaded into the microneedles of the soluble microneedle transdermal drug delivery system using the preparation method in Example 2. After loading, the soluble microneedle transdermal drug delivery system was inverted, and fluorescence observation was performed to confirm that the fluorescent dye Cy5.5 had been loaded into the microneedles.

[0046] The soluble microneedle transdermal drug delivery system prepared in Example 2 was used to transdermally treat the tumor site of mice, and optical imaging of the mice was obtained at different time points. After observation, it was found that the fluorescence intensity of the tumor site of the mouse was significantly higher than that of other parts, which verified that the soluble microneedle transdermal drug delivery system prepared by the present invention can enrich the drug in the tumor site after transdermal administration and can be used in tumor treatment.

[0047] Example 5

[0048] In order to verify the relationship between the amount of boron loaded in the soluble microneedle transdermal drug delivery system loaded with BSH and the concentration of the BSH solution used in the preparation process. This example uses the preparation method in Example 2 to prepare a soluble microneedle transdermal drug delivery system loaded with BSH, prepares BSH solutions of different concentrations according to the concentration gradient, and sequentially loads the BSH solutions of each concentration into the soluble microneedle and dissolves them in deionized water to form a mixed solution. The content of boron in the mixed solution is detected by ICP-MS, and the relationship between the amount of boron loaded in the soluble microneedle and the BSH concentration is obtained, as shown in FIG. Figure 3 As shown by Figure 3 It can be seen that there is a clear linear relationship between the boron loading amount of the soluble microneedles prepared in the present invention and the BSH solution.

[0049] The preparation method in Example 2 was used to prepare a soluble microneedle transdermal drug delivery system loaded with BSH using a BSH solution with a concentration of 23 mg / mL, that is, the boron concentration in the soluble microneedles was 13.6 mg / mL. Multiple mice were selected as research subjects. In this example, three mice were selected as samples. The soluble microneedle scalp drug delivery system was used to perform transdermal drug delivery on each mouse. After the microneedle acted on the mouse skin, the needle body penetrated the stratum corneum on the surface of the skin, and the puncture formed many small channels. The presence of these channels made it possible for macromolecular substances and water-soluble substances to enter the skin, so that the boron drug reached the dermis along the channels and reached the lesion site with the blood circulation for treatment. After 2.5 hours of transdermal drug delivery treatment, the mice were killed and the tumors, muscles, blood and major organs of each mouse were taken out. The boron content in the tumors, muscles, blood and major organs of each mouse was detected by ICP-MS, as shown in FIG. Figure 4 As shown, the results showed that the boron concentration in each mouse tumor reached more than 20ppm, but the boron concentration in each major organ was very low. At the same time, the ratio of the boron concentration in the tumor tissue of each mouse to that in the normal tissue, and the ratio of the boron concentration in the tumor tissue to that in the blood were all greater than 3:1. It can be concluded that the soluble microneedle scalp drug delivery system loaded with boron drug BSH prepared by the present invention is suitable for boron neutron capture therapy.

[0050] Example 6

[0051] In order to verify the application effect of the soluble microneedle transdermal drug delivery system loaded with BSH in the treatment of BNCT, mice were used as experimental subjects. The preparation method in Example 2 was used to prepare a soluble microneedle transdermal drug delivery system loaded with BSH using a BSH solution with a concentration of 23 mg / mL. The mice were transdermally administered. That is, the boron concentration in the soluble microneedle was 13.6 mg / mL. After 2.5 hours of transdermal drug delivery, the mice were irradiated with neutrons for 1 hour, and the radiation intensity was 2.57×10 8 cm-2·s -1 The tumor growth of mice was monitored for 20 days, the long and short diameters of the mouse tumor were measured every day, the tumor volume of the mouse was calculated, the change curve of the mouse tumor volume over time was obtained, the tumor inhibition curve of the mouse was drawn, and the mice were compared with the mice without transdermal administration as the control group. Figure 5 As shown, by comparison, the soluble microneedle transdermal drug delivery system loaded with BSH can effectively inhibit tumor growth and effectively prolong the survival time of mice during the BNCT process.

[0052] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A soluble microneedle transdermal drug delivery system loaded with BSH, It is characterized in that It includes a substrate and microneedles distributed in an array on the substrate, the microneedles and the substrate are both made of hyaluronic acid, the microneedles are set to a cone structure, and the boron drug BSH is loaded inside; The bottom diameter of the microneedle is not less than 300 μm, and the length of the microneedle is 500-1000 μm; The BSH-loaded soluble microneedle transdermal drug delivery system is prepared based on a vacuum drying method, comprising the following steps: Step 1, dissolving sodium undecahydromercaptododecaboride powder in water to prepare a BSH solution, and then dissolving hyaluronic acid powder in water to prepare a HA solution; Step 2, preparing a microneedle mold, ultrasonically cleaning the microneedle mold, injecting a BSH solution into the microneedle mold, so that the BSH solution fills the microneedle mold, placing the microneedle mold in a vacuum drying oven, and vacuuming to remove bubbles in the microneedle mold and exhaust the air in the microneedle mold; Step 3, taking the microneedle mold out of the vacuum drying oven, removing the deionized water in the microneedle mold, pouring the HA solution into the microneedle mold and ultrasonically mixing, placing the microneedle model in an air drying oven again, drying it in a vacuum environment, taking out the microneedle model, peeling it off and demolding it to obtain a soluble microneedle transdermal drug delivery system loaded with BSH; Step 4, encapsulating and irradiating the soluble microneedle transdermal drug delivery system loaded with BSH.

2. A method for preparing a BSH-loaded soluble microneedle transdermal drug delivery system according to claim 1, It is characterized in that The preparation of a soluble microneedle transdermal drug delivery system loaded with BSH based on a vacuum drying method includes the following steps: Step 1, dissolving sodium undecahydromercaptododecaboride powder in water to prepare a BSH solution, and then dissolving hyaluronic acid powder in water to prepare a HA solution; Step 2, preparing a microneedle mold, ultrasonically cleaning the microneedle mold, injecting a BSH solution into the microneedle mold, so that the BSH solution fills the microneedle mold, placing the microneedle mold in a vacuum drying oven, and vacuuming to remove bubbles in the microneedle mold and exhaust the air in the microneedle mold; Step 3, taking the microneedle mold out of the vacuum drying oven, removing the deionized water in the microneedle mold, pouring the HA solution into the microneedle mold and ultrasonically mixing, placing the microneedle model in an air drying oven again, drying it in a vacuum environment, taking out the microneedle model, peeling it off and demolding it to obtain a soluble microneedle transdermal drug delivery system loaded with BSH; Step 4, encapsulating and irradiating the soluble microneedle transdermal drug delivery system loaded with BSH.

3. A method for preparing a BSH-loaded soluble microneedle transdermal drug delivery system according to claim 2, It is characterized in that In the step 1, the concentration of the BSH solution is 3-50 mg / mL, and the mass fraction of the HA solution is 20%.

4. A method for preparing a BSH-loaded soluble microneedle transdermal drug delivery system according to claim 2, It is characterized in that In step 3, the temperature of the air drying oven is set to 42° C. during the drying process, and the drying time is set to 12 hours.

5. Use of a BSH-loaded soluble microneedle transdermal drug delivery system according to claim 1 in the preparation of boron neutron capture therapy drugs.

6. Use of a BSH-loaded soluble microneedle transdermal drug delivery system according to claim 5 in the preparation of boron neutron capture therapy drugs, It is characterized in that After administration using a soluble microneedle transdermal drug delivery system loaded with BSH, BSH is enriched in tumor tissue, and the boron concentration in the tumor tissue is not less than 20 ppm.

7. Use of a BSH-loaded soluble microneedle transdermal drug delivery system according to claim 5 in the preparation of boron neutron capture therapy drugs, It is characterized in that After administration using a soluble microneedle transdermal drug delivery system loaded with BSH, the boron concentration ratio in tumor tissue to normal tissue is not less than 3:1, and the boron concentration ratio in tumor tissue to blood is not less than 3:1.

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