Intravascular embolization composition and preparation method and application thereof

Abstract

The present application relates to an intravascular embolization composition and its preparation method and application. The intravascular embolization composition comprises a complex formed by electrostatic action of a polycationic compound and a polyphenolic compound, a contrast agent and water. The intravascular embolization composition has a suitable gelation time, injection force and mechanical properties, can effectively load and release drugs, is not prone to radiological artifacts, and has good biocompatibility and degradability.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to an intravascular embolization composition and a preparation method and application thereof. Background Art

[0002] Intravascular embolization is a technique that delivers embolic agents to target blood vessels through catheters to block target blood vessels for therapeutic purposes. This technique has the advantages of being minimally invasive, efficient, precise, and repeatable, and has been widely used in the treatment of aneurysms, vascular malformations, hemorrhagic lesions, and benign and malignant tumors. At present, commercial liquid embolic agents mainly include n-butyl-cyanoacrylate (nBCA), Onyx (main components ethylene-vinyl alcohol copolymer and dimethyl sulfoxide), and iodized oil. They all have the problem of easy adhesion to the tube to varying degrees, unable to diffuse into the distal microvessels, using organic solvents, unable to effectively degrade or the degradation products have potential harm to the human body, unable to closely cross-link with contrast agents, which may lead to incomplete embolism or ectopic embolism, prone to radiological artifacts, and unable to effectively load and release drugs. There are also methods for preparing by reacting 1,2-dithiolane compounds, polyphenol compounds, and alkaloids in organic solvents, but they still have problems such as the need to use organic solvents and a long gelation time, and the research on material degradability and ectopic embolism is not involved. Summary of the invention

[0003] Based on this, the present application provides an intravascular embolization composition. The intravascular embolization composition has suitable gelation time, injection force and mechanical properties, can effectively load and release drugs, is not prone to produce radiological artifacts, and has good biocompatibility and degradability.

[0004] In a first aspect of the present application, an intravascular embolization composition is provided, comprising a complex formed by electrostatic interaction between a polycationic compound and a polyphenol compound, a contrast agent and water.

[0005] In some of the embodiments, in the composite, the mass ratio of the polycationic compound to the polyphenol compound is (0.05-9):(0.1-27).

[0006] In some embodiments, the polycationic compound comprises one or both of quaternized chitosan and polyethyleneimine; and / or,

[0007] The polyphenolic compounds include one or more of tannic acid, gallic acid and caffeic acid.

[0008] In some embodiments, the contrast agent includes one or more of iodine contrast agent, liquid metal and tantalum powder.

[0009] In some embodiments, the intravascular embolization composition further comprises a drug, wherein the drug comprises one or more of an alkylating agent, an antimetabolite drug, an anticancer antibiotic, a botanical drug, a hormone, a platinum drug, asparaginase and dacarbazine.

[0010] The second aspect of the present application provides a method for preparing the intravascular embolization composition according to the first aspect, comprising the following steps:

[0011] dissolving a polycationic compound in water to prepare a polycationic compound solution;

[0012] dissolving the polyphenol compound in water to prepare a polyphenol compound solution;

[0013] Mixing the polycationic compound solution with the polyphenol compound solution to prepare a mixed solution;

[0014] A contrast agent is added to the mixed solution.

[0015] In some embodiments, the method for preparing the intravascular embolic composition has at least one of the following characteristics:

[0016] (1) The mass concentration of the polycationic compound solution is 0.5% to 10%;

[0017] (2) The mass concentration of the polyphenol compound solution is 1% to 30%;

[0018] (3) The mass ratio of the polycationic compound solution to the polyphenol compound solution is 1:9 to 9:1.

[0019] In some embodiments, the mass ratio of the mixed solution to the contrast agent is 5:5 to 9:1; and / or,

[0020] The method further comprises the step of adding a drug to the mixed solution, wherein the mass ratio of the total mass of the mixed solution and the contrast agent to the drug is 5:5 to 9:1.

[0021] The third aspect of the present application provides a drug-loaded hydrogel, which is formed by reacting the intravascular embolization composition described in the first aspect or the intravascular embolization composition prepared by the preparation method described in the second aspect with a solution containing metal ions.

[0022] In one embodiment, the solution containing metal ions includes blood; and / or the metal ions include one or more of sodium ions, potassium ions, copper ions, magnesium ions, calcium ions, iron ions and aluminum ions.

[0023] The fourth aspect of the present application provides the use of the intravascular embolic composition described in the first aspect, the intravascular embolic composition prepared by the preparation method described in the second aspect, or the drug-loaded hydrogel described in the third aspect in the preparation of an intravascular embolic agent.

[0024] Different from the material scheme of directly making hydrogel by traditional methods, the above intravascular embolization composition uses polycationic compounds and polyphenolic compounds as raw materials, and forms a complex by electrostatic bonding between the two, and then combines with a developer, wherein the polycationic compound is a water-soluble cationic polymer, which can form an electrostatic effect with anionic compounds, and the hydroxyl and amino groups contained in it are easy to form hydrogen bonds with the hydroxyl, carboxyl or aldehyde groups of other molecules, and the polyphenolic compound is a natural small molecule containing a large number of phenolic hydroxyl groups, which can form electrostatic effects with the amino groups of other molecules, or form hydrogen bonds with the hydroxyl, carboxyl or aldehyde groups of other molecules, and the large number of phenolic hydroxyl groups are also easy to form coordination bonds with metal ions. After entering a solution containing metal ions such as blood, the composition can further combine through coordination bonds to form a three-dimensional gel network, thereby obtaining a hydrogel material, that is, it can form intravascular embolism in the blood vessel. The intravascular embolization composition has the following advantages:

[0025] 1) Polycationic compounds and polyphenolic compounds are mostly natural macromolecules and small molecules with good biocompatibility and biodegradability;

[0026] 2) The polycationic compounds and polyphenolic compounds form complexes through electrostatic interaction, and then further form hydrogels through ionic cross-linking in blood or other body fluids without the need for additional cross-linking agents;

[0027] 3) No organic solvent required;

[0028] 4) Injection force, gelation time and mechanical properties are adjustable;

[0029] 5) Ability to effectively load and release drugs;

[0030] 6) Stable mechanical properties, which can effectively embolize blood vessels without recanalization;

[0031] 7) The formed hydrogel is tightly cross-linked with the contrast agent through non-covalent bonds;

[0032] 8) Excellent intravascular diffusion;

[0033] 9) No ectopic embolism;

[0034] 10) Non-stick tube;

[0035] 11) No radiological artifacts. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1It is a schematic diagram of the gelation of the intravascular embolic composition in an example of the present application in different ion solutions with different concentrations;

[0037] Figure 2 X-ray fluoroscopic images (a) and CT values ​​(b) of intravascular embolization compositions containing different concentrations of iohexol (Iohexol, I) and iodized oil in an example of the present application;

[0038] Figure 3 Fourier transform infrared spectra of QCS, TA, iohexol, QT hydrogel, and QTI hydrogel in an example of the present application;

[0039] Figure 4 The gelation process (a) and gelation time (b) of the intravascular embolic composition in an example of the present application;

[0040] Figure 5 The injection force of the intravascular embolic composition with different QCS and TA ratios in an example of the present application in 1.7-F, 2.7-F and 4-F catheters;

[0041] Figure 6 In an example of the present application: (a) shear frequency scan of intravascular embolic compositions with different QCS and TA ratios; (b) time amplitude scan of intravascular embolic composition hydrogels with different QCS and TA ratios; (c) time amplitude scan of intravascular embolic composition hydrogels with fixed frequency and fixed strain at different time points;

[0042] Figure 7 In an example of this application: (a) stress-strain curves of intravascular embolization composition hydrogels with different QCS and TA ratios; (b) compressive stress; (c) compressive strain; (d) stress-strain curves of QTI-3 hydrogels at different time points; (e) compressive stress; (f) compressive strain;

[0043] Figure 8 (a) loading rate and (b) release rate of doxorubicin in the hydrogel of the intravascular embolic composition in one example of the present application;

[0044] Fig. 9 In an example of this application: (a) hemolysis photo (left) and hemolysis rate (right) of the intravascular embolic composition; (b) live-dead staining (left) and cell activity (right) of human umbilical vein endothelial cells (HUVECs);

[0045] Fig.10 In one example of the present application: (a) subcutaneous transplantation of hydrogel of intravascular embolization composition in rats, (b) changes in volume and degradation rate of hydrogel after subcutaneous transplantation;

[0046] Fig.11 In an example of the present application: (ac) digital subtraction angiography (DSA) images before right renal artery embolization of New Zealand rabbits (a), intraoperative X-ray fluoroscopy images (b) and DSA images after embolization (c); (dg) contrast-enhanced computed tomography (CECT) (d), CT angiography (CTA) (e), color Doppler flow imaging (CDFI) (f) and contrast-enhanced ultrasound (CEUS) (g) images before and on days 7, 14 and 28 after embolization of the right kidney;

[0047] Fig.12 Masson staining of New Zealand rabbit kidneys after intravascular embolization with hydrogel composition in an example of the present application and in a control group;

[0048] Fig.13 This is an X-ray fluoroscopic image of the process of tube removal after intravascular embolization of the hydrogel composition for embolization of the right renal artery of a New Zealand rabbit in an example of the present application;

[0049] Fig.14 This is a CT image of the right kidney of a New Zealand rabbit after embolization of the right renal artery with the intravascular embolization composition hydrogel and nBCA in an example of the present application;

[0050] Fig.15 In an example of this application: (ac) DSA images of normal femoral artery of New Zealand rabbit (a), femoral artery with active bleeding (b) and femoral artery after embolization (c); (df) CTA (d), CECT (e) and CDFI (f) images before femoral artery embolization and on days 7 and 28 after embolization. DETAILED DESCRIPTION

[0051] The following is a further detailed description of the intravascular embolization composition of the present application and its preparation method and application in conjunction with specific examples. The present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0053] The optional scope of the terms "and / or", "or / and", and "and / or" used in this article includes any one of two or more related listed items, and also includes any and all combinations of the related listed items, said any and all combinations include any combination of any two related listed items, any more related listed items, or all related listed items.

[0054] As used herein, "one or more" refers to any one, any two, or any two or more of the listed items.

[0055] In this application, "first aspect", "second aspect", "third aspect", "fourth aspect", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0056] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0057] In this application, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0058] The percentage contents involved in this application, unless otherwise specified, refer to mass percentage for solid-liquid mixing and solid-solid mixing, and refer to volume percentage for liquid-liquid mixing.

[0059] The percentage concentrations mentioned in this application, unless otherwise specified, refer to the final concentration, which refers to the percentage of the added component in the system after the addition of the component.

[0060] The temperature parameters in this application, unless otherwise specified, allow for both constant temperature treatment and treatment within a certain temperature range. The constant temperature treatment allows the temperature to fluctuate within the accuracy range of instrument control.

[0061] The room temperature in this application generally refers to 4°C~30°C, preferably 20±5°C.

[0062] In some examples of the present application, an intravascular embolization composition is provided, comprising a complex formed by electrostatic interaction between a polycationic compound and a polyphenol compound, a contrast agent, and water.

[0063] In some of the examples, the polycationic compound and the polyphenolic compound further form the complex through hydrogen bonding.

[0064] In some examples, in the composite, the mass ratio of the polycationic compound to the polyphenolic compound is (0.05-9):(0.1-27). Specifically, the mass ratio of the polycationic compound to the polyphenolic compound includes but is not limited to: 0.05:0.1, 0.05:27, 2:8, 3:7, 4:2, 4:4, 4:6, 6:4, 8:2, 9:0.1, 9:27 or a range between any two of the foregoing. Further, the mass ratio of the polycationic compound to the polyphenolic compound is (0.5-10):(1-30). Further, the mass ratio of the polycationic compound to the polyphenolic compound is (2-6):(4-8).

[0065] In some examples, the contrast agent includes one or more of an iodine contrast agent, a liquid metal, and a tantalum powder. Without limitation, the iodine contrast agent may be iohexol, iodixanol, iopamoate, iodinepamoate, iopromide, euvichrome, iofosin, etc. The iodine contrast agent contains a large number of hydroxyl groups, which are easy to form hydrogen bonds with amino groups, hydroxyl groups on polycationic compounds and / or hydroxyl groups on polyphenolic compounds. The oxygen-containing groups on the surface of the liquid metal are easy to form hydrogen bonds with amino groups, hydroxyl groups and / or hydroxyl groups on polycationic compounds and / or hydroxyl groups on polyphenolic compounds. For the convenience of room temperature or low temperature storage, a liquid metal with a melting point below 37 ° C is selected, preferably an alloy based on metal gallium, such as gallium-indium alloy and gallium-indium-tin alloy. Tantalum powder microparticles can be combined with polyphenolic compounds through metal chelation. The above contrast agents can all give the hydrogel the ability to be opaque to X-rays, so as to avoid incomplete embolism or ectopic embolism during surgery. Among them, the contrast agent is preferably an iodine contrast agent with good water solubility, no radiological artifacts, and easy absorption and metabolism.

[0066] In some examples, the intravascular embolization composition also includes drugs. Without limitation, the drugs are chemotherapy drugs, including alkylating agents (cyclophosphamide, ifosfamide, lomustine, semustine, thiotepa, etc.), antimetabolites (fluorouracil, methotrexate, cytarabine, mercaptopurine, etc.), anticancer antibiotics (adriamycin, doxorubicin, pirarubicin, epirubicin, bleomycin, mitomycin, actinomycin D), etc., botanical drugs (paclitaxel, gemcitabine, irinotecan, vinblastine, vincristine, vindesine, vinorelbine, etoposide, teniposide, etc.), hormones (prednisone, dexamethasone, tacimofen, letrozole, etc.), miscellaneous (platinum, asparaginase, dacarbazine, etc.) one or more. Further, the drugs include one or more of adriamycin, epirubicin, pirarubicin, paclitaxel, gemcitabine and irinotecan.

[0067] Some other examples of the present application also provide a method for preparing an intravascular embolization composition, comprising the following steps:

[0068] dissolving a polycationic compound in water to prepare a polycationic compound solution;

[0069] dissolving the polyphenol compound in water to prepare a polyphenol compound solution;

[0070] Mixing the polycationic compound solution with the polyphenol compound solution to prepare a mixed solution;

[0071] Contrast agent and drugs are added to the mixed solution.

[0072] It can be understood that in the process of preparing the mixed solution, the polycationic compound is a water-soluble cationic polymer, which can form an electrostatic effect with the anionic compound. In addition, the hydroxyl and amino groups contained in it are easy to form hydrogen bonds with the hydroxyl, carboxyl or aldehyde groups of other molecules. The polyphenol compound is a natural small molecule containing a large number of phenolic hydroxyl groups. The phenolic hydroxyl groups can form electrostatic effects with the amino groups of other molecules, or form hydrogen bonds with the hydroxyl, carboxyl or aldehyde groups of other molecules. In addition, its large number of phenolic hydroxyl groups are also easy to form coordination bonds with metal ions. After adding contrast agents and drugs, they can be combined with the formed complex through hydrogen bonds, electrostatic effects or metal chelation to obtain a self-developable drug-loaded hydrogel precursor solution.

[0073] It can be understood that the above preparation method also includes the features of the aforementioned intravascular embolization composition.

[0074] Without limitation, the above steps are all carried out at room temperature.

[0075] In some examples, the mass concentration of the polycationic compound solution is 0.5% to 10%. Specifically, the mass concentration of the polycationic compound solution includes but is not limited to: 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% or a range between any two of the foregoing.

[0076] In some examples, the mass concentration of the polyphenol compound solution is 1% to 30%. Specifically, the mass concentration of the polyphenol compound solution includes but is not limited to: 1%, 2%, 4%, 6%, 10%, 15%, 20%, 25%, 30% or a range between any two of the foregoing.

[0077] In some examples, the mass ratio of the polycationic compound solution to the polyphenolic compound solution is 1:9 to 9:1. Specifically, the mass ratio of the polycationic compound solution to the polyphenolic compound solution includes but is not limited to: 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, 9:1 or a range between any two of the foregoing.

[0078] In some examples, the mass ratio of the mixed liquid to the contrast agent is 5:5 to 9:1. Specifically, the mass ratio of the mixed liquid to the contrast agent includes but is not limited to: 5:5, 6:4, 7:3, 8:2, 9:1 or a range between any two of the foregoing.

[0079] In some examples, the preparation method further includes the step of adding a drug to the mixed solution, and the mass ratio of the total mass of the mixed solution and the contrast agent to the drug is 55:5 to 9:1. Specifically, the mass ratio of the mixed solution to the contrast agent includes but is not limited to: 5:5, 6:4, 7:3, 8:2, 9:1 or a range between any two of the foregoing.

[0080] In some other examples of the present application, a drug-loaded hydrogel is provided, which is formed by reacting the intravascular embolization composition as described above or the intravascular embolization composition prepared by the preparation method as described above with a solution containing metal ions.

[0081] In some examples, the solution containing metal ions includes blood. It can be understood that it can also be other body fluids or phosphate buffer or different ion solutions.

[0082] In some examples, the metal ions include one or more of sodium ions, potassium ions, copper ions, magnesium ions, calcium ions, iron ions, and aluminum ions.

[0083] In some examples, the concentration of the solution containing metal ions is ≥ 0.01 mol / L. Specifically, the concentration of the solution containing metal ions includes, but is not limited to, 0.01 mol / L, 0.0175 mol / L, 0.035 mol / L, 0.07 mol / L, 0.14 mol / L, 0.25 mol / L, 0.5 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, or a range between any two of the foregoing.

[0084] In other examples of the present application, use of the intravascular embolic composition, the intravascular embolic composition prepared by the preparation method described in the second aspect, or the drug-loaded hydrogel described in the third aspect in the preparation of an intravascular embolic agent is provided. The intravascular embolic agent can be used for embolic treatment of vascular malformations, aneurysms, hemorrhagic lesions, and various benign and malignant tumors (such as hepatic hemangiomas, uterine fibroids, primary liver cancer, liver metastases, lung cancer, tongue cancer, nasopharyngeal cancer, prostate cancer, cervical cancer, endometrial cancer, etc.).

[0085] For experimental parameters not specified in the following specific embodiments, reference is made to the instructions given in the present application document, and reference may also be made to experimental manuals in the art or other experimental methods known in the art, or to experimental conditions recommended by manufacturers.

[0086] The raw materials and reagents involved in the following specific examples can be obtained from commercial sources, or can be prepared by those skilled in the art according to known methods.

[0087] Example 1

[0088] This embodiment is a quaternized chitosan / tannic acid intravascular embolization composition, and its preparation method is as follows:

[0089] Step 1): quaternary ammonium chitosan powder (QCS) was dissolved in deionized water to prepare a quaternary ammonium chitosan solution with a concentration of 4 wt%; tannic acid powder (TA) was dissolved in deionized water to prepare a solution with a concentration of 4 wt%.

[0090] Step 2): The two solutions prepared in step 1) are fully mixed at a mass ratio of 50%:50% to obtain a quaternized chitosan / tannic acid solution (QT solution).

[0091] Step 3): Add iodine contrast agent iohexol to the quaternary ammonium chitosan / tannic acid solution prepared in step 2), with the mass ratio of solution to iohexol being 7.5:2.5, to obtain an X-ray-opaque quaternary ammonium chitosan / tannic acid / developer mixed solution (QTI solution).

[0092] Step 4): The quaternary ammonium chitosan / tannic acid / developer mixed solution prepared in step 3) is mixed with the chemotherapeutic drug doxorubicin, with the mass ratio of the solution to the chemotherapeutic drug being 8:2, to obtain a drug-loaded, radiopaque quaternary ammonium chitosan / tannic acid intravascular embolization composition.

[0093] Test Example 1

[0094] This test example investigates the process of preparing a hydrogel from a quaternary ammonium chitosan / tannic acid intravascular embolization composition.

[0095] According to the preparation method of the quaternized chitosan / tannic acid intravascular embolization composition of Example 1, without adding drugs and contrast agents, the prepared samples were injected into phosphate buffered saline (PBS solution, an ion solution of physiological concentration) and different concentrations of NaCl, KCl, NaHCO3, Na2SO4, CaCl2, MgCl2, AlCl3, and FeCl3, and hydrogels were formed in situ within a certain concentration range (Table 1, Figure 1 ).

[0096] Table 1 Gel formation in different ion solutions with different concentrations

[0097]

[0098] Note: “√” indicates gelation, “×” indicates gelation failure.

[0099] Test Example 2

[0100] This test example examines the X-ray opacity of the quaternary ammonium chitosan / tannic acid intravascular embolization composition.

[0101] According to the same method as in Example 1 for preparing the quaternized chitosan / tannic acid intravascular embolization composition (without adding drugs), samples with a total mass percentage of iohexol (I) of 0 wt%, 10 wt%, 15 wt%, 20 wt%, and 25 wt% in the composition were prepared, and the X-ray opacity of each sample was evaluated by X-ray fluoroscopy and computed tomography (CT). It can be seen that the iohexol content of 25 wt% (i.e., the mass ratio of the solution to iohexol in Example 1 is 7.5:2.5) has an excellent imaging effect ( Figure 2 In a), its CT value is equivalent to that of iodized oil ( Figure 2 Therefore, the quaternized chitosan / tannic acid intravascular embolization composition (QTI solution) with iohexol content of 25 wt% was used for subsequent experiments.

[0102] Test Example 3

[0103] This test example investigates the gelation mechanism of the quaternary ammonium chitosan / tannic acid intravascular embolization composition.

[0104] The QCS, TA, iohexol powders, QT hydrogel (hydrogel formed by mixing the QT solution in Example 1 with the PBS solution), and QTI hydrogel (hydrogel formed by mixing the QTI solution in Example 1 with the PBS solution) in Example 1 were freeze-dried and subjected to Fourier-transform infrared spectroscopy (FTIR) detection. The FTIR results showed that -NH 3+ (1647 cm –1 ) and -NH2 (1475 cm –1 ) characteristic peak disappeared after TA was added, indicating that QCS and TA were cross-linked by electrostatic interaction, and TA formed coordination bonds with metal ions ( Figure 3 In addition, the -OH of QCS (3284 cm –1 ) and -OH of TA (3230 cm –1 ) shifted to 3180 cm on QT –1 , indicating that QCS and TA form hydrogen bonds. After adding I, its -OH group increases from 3180 cm –1 Shift to 3265 cm –1 , suggesting that hydrogen bonds are formed between I and QCS and TA ( Figure 3 (b)

[0105] Test Example 4

[0106] This test example investigates the gelation process and time of the quaternized chitosan / tannic acid intravascular embolization composition.

[0107] 0.5 mL of QTI solution was injected into PBS solution (37 °C), and the solution was taken out at a set time point for observation and photography to record the gelation process. The results showed that the QTI solution exhibited an "outside-in" gelation process, that is, the outer layer of the solution first contacted the ions and instantly cross-linked to form a gel, and then the ions gradually entered the inner layer, causing the remaining solution to form a gel ( Figure 4 (a).

[0108] In addition, the gelation time of the QTI solution was measured using the centrifuge tube inversion method. 1 mL of QTI solution with different QCS and TA concentrations (Table 2, prepared according to the method of Example 1, without adding drugs) was injected into a 5 mL centrifuge tube containing PBS solution, and the centrifuge tube was placed in a constant temperature water bath at 37°C. The centrifuge tube was inverted at the set time point to observe the fluidity of the liquid. If the solution still had no fluidity within 30 seconds after inversion, it was judged to be gel formation, and the gelation time was recorded at the same time. The results showed that when the TA content increased from 4 wt% to 8 wt%, the corresponding gelation time was shortened from 5.9 ± 0.3 min to 0.4 ± 0.1 min ( Figure 4 (b)

[0109] Table 2 QTI solutions with different QCS and TA concentrations

[0110]

[0111] Test Example 5

[0112] This test example examines the injectability of the quaternized chitosan / tannic acid intravascular embolic composition.

[0113] First, the upper end of a 1 mL screw-mouth syringe was placed in contact with a pressure plate, and the lower end was fixed vertically by a clamp and connected to catheters of different specifications. 1 mL of QTI solution (Table 2, prepared according to the method of Example 1 without adding drugs) with different QCS and TA ratios and PBS were added to the syringe, and the lower end was connected to 1.7-F, 2.7-F and 4-F catheters, respectively. Then, the syringe was pressed at a uniform speed (flow rate: 1 mL / min) using the upper pressure plate, and the change in the pressure of the upper pressure plate was recorded at the same time. The results showed that the higher the QCS concentration, the smaller the inner diameter of the catheter, and the greater the injection force required. Taking the 1.7-F microcatheter as an example, when the QCS concentration was 6 wt% (QTI-1), the solution injection force was 59.4 ± 3.0 N, while when the QCS concentration dropped to 2 wt% (QTI-5), the injection force was 2.9 ± 0.4 N. In addition, the injection force of the QCS solution at a concentration of 4 wt% (QTI-3) in a 1.7-F microcatheter and a 4-F angiographic catheter was 8.2 ± 0.8 N and 4.1 ± 0.1 N, respectively ( Table 2 , Figure 5 ).

[0114] Test Example 6

[0115] This test example investigates the rheological properties of the quaternized chitosan / tannic acid intravascular embolization composition.

[0116] Rheological experiments were performed using an Anton Paar MCR 92 rheometer with a parallel plate system (diameter = 25 mm), and all tests were repeated three times at T = 37 ± 0.2 °C. First, QTI solutions with different QCS and TA concentrations (Table 2, prepared according to the method of Example 1 without adding drugs) were stirred at shear rates of 0.1-1000 s –1 The variable shear rate test of QTI solution was carried out in the range of . The results showed that QTI solution has shear thinning characteristics, and the viscosity decreases with the decrease of QCS content ( Figure 6 Then, QTI hydrogel samples were prepared in PBS solution, and time oscillation scanning was performed under constant strain (1%) and constant angular frequency (ω = 10 rad / s). The results showed that the storage modulus (storage modulus, G') of all samples was higher than the loss modulus (loss modulus, G''), which confirmed that QTI solution can form hydrogel in PBS. In addition, QTI-3 hydrogel has the largest storage modulus and loss modulus, indicating that a relatively dense hydrogel three-dimensional skeleton is formed by electrostatic interaction between QCS and TA at this ratio ( Figure 6 b). Finally, the QTI-3 hydrogel was immersed in a PBS solution at 37°C and subjected to time oscillation scanning at a set time. The results showed that the storage modulus and loss modulus of the QTI-3 hydrogel continued to increase on the third day, and then gradually decreased. The possible reason was that the hydrogel was exposed to ions (Na + , K + , Ca 2+ The coordination bonds formed with TA gradually increased, resulting in denser crosslinking. After 3 days, the hydrogel gradually degraded, resulting in a decrease in modulus ( Figure 6 (c).

[0117] Test Example 7

[0118] This test example investigates the compression performance of the quaternized chitosan / tannic acid intravascular embolization composition.

[0119] The test was carried out using an electronic universal testing machine. The experimental steps are as follows: 1) 2.0 mL of QTI solution (QTI solutions with different QCS and TA concentrations (Table 2, prepared according to the method of Example 1, without adding drugs)) was injected into a mold filled with PBS solution to prepare hydrogels of the same shape and size (cylindrical, diameter = 2 cm, thickness = 1.5 cm). In order to ensure that it is completely gelled, the QTI solution is injected into the mold for 5 minutes before being taken out for testing; 2) Calibrate the instrument and set the experimental parameters (downward movement speed is 0.5 mm / min, preload force is 0.005 N); 3) Place the sample on the compression plate and adjust and fix it to ensure that it is stable and level; 4) Start the universal testing machine and test according to the set parameters. During the test, observe the deformation of the sample, and monitor and record the changes in compressive stress and strain in real time. The results show that QTI-3 hydrogel ( Figure 7 In addition, the QTI-3 hydrogel was immersed in PBS at 37 °C and subjected to compression test at set time points. The results showed that the compressive stress and strain of the QTI-3 hydrogel continued to increase on the third day and then gradually decreased. The results were consistent with the rheological results ( Figure 7 (d, e, f).

[0120] In summary, the hydrogels derived from QTI solutions have adjustable gelation time, injection force, and mechanical properties. Among them, QTI-3 has a suitable gelation time, low injection force, and stable mechanical properties, so it was used for subsequent experiments.

[0121] Test Case 8

[0122] This test example investigates the drug loading and release properties of the quaternized chitosan / tannic acid intravascular embolization composition.

[0123] First, doxorubicin (DOX) solutions with concentrations of 16, 8, 4, 2, 1, 0.5, 0.25, and 0.125 mg / mL were prepared using PBS solution. The absorbance values ​​of DOX solutions with different concentrations were measured at 480 nm using a spectrophotometer. A standard curve was drawn based on the DOX concentration and the corresponding absorbance value. Then, QTI-3 solution (8 mg) and DOX (2 mg) were mixed with each other to obtain QT / DOX solution. In addition, lipiodol / DOX emulsion was used as a control. The specific preparation method of the emulsion was to mix 2 mL of lipiodol, 4 mL of sterile water for injection, and 30 mg of DOX to obtain Lipiodol / DOX emulsion. QT / DOX solution (2 mL) or Lipiodol / DOX emulsion (2 mL) was injected into 10 mL of PBS solution, and the supernatant was immediately aspirated to determine the absorbance value. The DOX concentration corresponding to the absorbance was calculated using the standard curve. Calculate the amount of DOX that was not loaded into the hydrogel based on the DOX concentration. Amount of DOX (a) = c × v (c and v represent the concentration and volume of DOX, respectively). DOX loading rate (%) = (a0 -a1) / a0 × 100% (a1 and a0 represent the loading amount and initial amount of DOX, respectively). In addition, aspirate the supernatant at set time points and measure their absorbance. Calculate the DOX concentration corresponding to the absorbance using the standard curve. DOX release rate (%) = a1 / a0 × 100% (a1 and a0 represent the release amount and initial amount of DOX, respectively). Figure 8 Figure a shows that the QTI-3 solution hydrogel can load 89.7 ± 2.9% of doxorubicin, while Lipiodol can only load 70.2 ± 7.2% of doxorubicin. The release curve shows that DOX is slowly released, with a release of 86.2 ± 3.3% on the 28th day, while Lipiodol shows a burst release, releasing 88.2 ± 2.6% within 24 hours ( Figure 8 (b)

[0124] Test Example 9

[0125] This test example investigates the in vivo biocompatibility and degradability of the quaternary ammonium chitosan / tannic acid intravascular embolization composition.

[0126] Hemolysis experiment: Rabbit whole blood red blood cells were collected by centrifugation (200 × g, 10 min) and diluted to 5% (v / v) with normal saline. 100 µL of QTI-3 solution (hydrogel formed in situ in normal saline), normal saline (negative control) and deionized water (positive control) were added to 1 mL of the above blood cell solution and incubated in a 37 °C constant temperature water bath for 24 h. After the red blood cell suspension was centrifuged (500 × g, 15 min), the supernatant was transferred to a 96-well plate and the absorbance of the solution at 540 nm was tested using an ELISA reader. The hemolysis rate was calculated as follows: Hemolysis rate (%) = (A s -A n ) / (A d -A n )×100%(A s , A n and A d are the absorbance of QTI hydrogel, saline and deionized water groups respectively). Fig. 9 The transparency of the supernatant of the QTI hydrogel group shown in a is close to that of the normal saline group, and its hemolysis rate is less than 5%, confirming its good blood compatibility.

[0127] Cytotoxicity experiment: Human umbilical vein endothelial cells (HUVECs) were added to a 12-well plate (25,000 cells / well) and incubated in a 37°C incubator for 24 h. Then, 0.5 mL of QTI-3 solution (hydrogel formed in situ in culture medium) was added to the wells containing cells, and the group with normal culture medium was used as a positive control. After incubation for 24 h, cell viability was assessed by live / dead cell staining. The results are shown in Figure 2. Fig. 9 As shown in b, the cell survival rates of all groups were greater than 98%, and the cells showed a normal spreading spindle shape. This result shows that the hydrogel has no cytotoxicity and has good cell compatibility.

[0128] In vivo degradation experiment: During the experiment, rats (Wistar, 6-8 weeks, male) were anesthetized with isoflurane. The back of the rat was locally prepared, disinfected, and covered with a sterile sheet. 0.5 mL of QTI-3 solution was injected into the subcutaneous tissue of the rat's back to form an in situ gel. The volume of the hydrogel was measured and photographed on the 7th, 14th, and 28th days after surgery, and then the hydrogel was taken out, dried, and weighed (n = 4). The results showed that the volume of the hydrogel gradually decreased in the subcutaneous tissue ( Fig.10 In a), the degradation rate was 29.5 ± 3.8% on day 28 ( Fig.10 (b)

[0129] Test Example 10

[0130] This test example investigated the embolization of the renal artery of New Zealand rabbits using the quaternized chitosan / tannic acid intravascular embolization composition.

[0131] All New Zealand rabbits (2.4-3.0 kg, male) in the experiments were anesthetized with Zota 50 (5 mg / kg, intramuscular injection) and 2% xylazine (2 mg / kg, intramuscular injection). The specific experimental steps are as follows: 1) The skin of the left inguinal area was prepared, disinfected, and covered with a sterile sheet; 2) The skin, muscle, and fascia were cut open, and the femoral artery was bluntly separated layer by layer; 3) The distal end of the femoral artery was ligated, and the proximal end was temporarily clamped with an artery clamp and a 2-0 suture was reserved; 4) The anterior wall of the femoral artery was cut open with microscissors, and a 1.7-F microcatheter was immediately inserted. The microcatheter was fixed with a slipknot using the reserved suture, and the artery clamp was loosened and the microcatheter was continued to be advanced; 5) The microguidewire and microcatheter were selectively inserted into the right renal artery under real-time X-ray fluoroscopy, and the microguidewire was withdrawn and angiography was performed to confirm whether the renal artery was patency ( Fig.11 6) Slowly inject 0.4 mL of QTI-3 solution or nBCA under strict X-ray fluoroscopy monitoring, and pay attention to whether there is reflux or ectopic embolism during the injection ( Fig.11 Middle b); 7) After embolization, the right renal artery and its small branches disappeared in the follow-up angiography ( Fig.11 c), indicating successful embolization. Abdominal enhanced CT scans on days 7, 14, and 28 after surgery showed no enhancement of the right kidney and its volume gradually decreased ( Fig.11 Middle d), Renal artery CT angiography (CTA) showed disappearance of the right renal artery without recanalization ( Fig.11 Middle e), color Doppler flow imaging (CDFI) showed that the blood flow signal of the right kidney disappeared ( Fig.11 Middle f), contrast-enhanced ultrasound (CEUS) shows no blood perfusion in the right kidney ( Fig.11 g).

[0132] At the set time point, the New Zealand rabbits were euthanized, and the right kidney was removed and fixed in formalin for 24 hours. Subsequently, the samples were dehydrated, paraffin-embedded, sectioned, and further stained with Masson. The results showed that the number of cell nuclei in the glomeruli and tubules in the renal parenchyma decreased significantly on the 14th day after embolization, and the nuclei of the glomeruli and tubules disappeared on the 28th day, and extensive coagulative necrosis occurred in the renal parenchyma. In addition, the fibrosis of the renal artery wall was reconstructed after embolization, and a large amount of fibrous tissue proliferated in the renal interstitium ( Fig.12). It is worth noting that QTI-3 hydrogel is widely distributed and continuously cast in the renal artery and its small branches, and the hydrogel can diffuse into small blood vessels with a diameter of 15 µm (black arrow). The above imaging and pathological results show that QTI hydrogel can effectively embolize the renal artery and diffuse to the distal small branches. There is no recanalization of the blood vessels after surgery, which eventually leads to renal ischemic necrosis.

[0133] In addition, QTI-3 hydrogel does not stick to the catheter after delivery, is easy to remove, and does not cause ectopic embolism ( Fig.13 , white arrow). Postoperative review showed that there was no contrast agent retention and radiological artifacts in the right kidney after QTI-3 hydrogel embolization, while there was iodized oil deposition in the right kidney after nBCA embolization, resulting in irregular strip-shaped radiological artifacts ( Fig.14 , black arrow)

[0134] Test Example 11

[0135] This test example investigates the embolization of femoral artery hemorrhage in New Zealand rabbits using the quaternized chitosan / tannic acid intravascular embolization composition.

[0136] The anesthesia method is the same as that of the renal artery embolization in test case 10. The specific experimental steps are as follows: 1) Prepare the skin of the neck and left groin area, disinfect, and lay a sterile sheet; 2) Make a midline incision in the neck, cut the skin, muscle, and fascia in turn, and bluntly separate the left carotid artery layer by layer; 3) The catheterization steps are similar to those of the femoral artery; 4) Selectively insert the microguidewire and microcatheter into the left femoral artery under real-time X-ray fluoroscopy to confirm whether it is patency ( Fig.15 5) Cut the skin, muscles and fascia of the inguinal area in turn, and bluntly separate the left femoral artery layer by layer; 6) Use a 22-G needle to puncture the left femoral artery to create an active bleeding model; 7) Angiography was performed again to see that the iodine contrast agent overflowed from the puncture point, indicating that the model was successful ( Fig.15 b); 8) Slowly inject 0.2 mL of QTI-3 solution under close monitoring of X-ray fluoroscopy, and pay attention to whether there is reflux and distal vascular embolism during the injection process; 9) After the embolization is completed, the angiography is repeated to confirm whether the embolization is successful. The results showed that there was no overflow of contrast agent after QTI-3 hydrogel embolization ( Fig.15 (c) indicates that QTI-3 hydrogel can effectively embolize the ruptured femoral artery and successfully stop bleeding. CECT and CTA showed no development of the embolized femoral artery 7 and 14 days after surgery ( Fig.15 Middle d, e), CDFI follow-up showed no blood flow signal in the embolized femoral artery ( Fig.15 In addition, CTA showed that there was no occlusion in the distal femoral artery, suggesting that QTI-3 hydrogel can be stably cast in the local blood vessels and will not shift to the distal end after surgery to cause ectopic embolism.

[0137] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0138] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the patent application. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the content of the attached claims, and the description can be used to interpret the content of the claims.

Claims

1. An intravascular embolization composition, characterized in that: The composition of the invention is a complex formed by electrostatic interaction between a polycationic compound and a polyphenolic compound, a contrast agent, water and a drug; The polycationic compound is quaternized chitosan; The polyphenol compound is tannic acid; In the composite, the mass ratio of the polycationic compound to the polyphenolic compound is 2:3; The preparation method of the intravascular embolization composition comprises the following steps: The polycationic compound is dissolved in water to prepare a polycationic compound solution; the concentration of the polycationic compound solution is 4wt%; dissolving the polyphenol compound in water to prepare a polyphenol compound solution; The concentration of the polyphenol compound solution is 6wt%; Mixing the polycationic compound solution with the polyphenol compound solution to prepare a mixed solution; Contrast agent and drugs are added to the mixed solution.

2. The intravascular embolization composition according to claim 1, characterized in that: The contrast agent includes one or more of iodine contrast agent, liquid metal and tantalum powder.

3. The intravascular embolization composition according to claim 1 or 2, characterized in that: The drugs include one or more of alkylating agents, antimetabolites, anticancer antibiotics, botanical drugs, hormones, platinums, asparaginase and dacarbazine.

4. A method for preparing an intravascular embolic composition, characterized in that: Here are the steps: Dissolving a polycationic compound in water to prepare a polycationic compound solution; the concentration of the polycationic compound solution is 4 wt %; dissolving the polyphenol compound in water to prepare a polyphenol compound solution; The concentration of the polyphenol compound solution is 6wt%; Mixing the polycationic compound solution with the polyphenol compound solution to prepare a mixed solution; adding contrast agent and drugs to the mixed solution; The polycationic compound is quaternized chitosan; The polyphenol compound is tannic acid; The mass ratio of the polycationic compound to the polyphenolic compound is 2:

3.

5. The method for preparing the intravascular embolic composition according to claim 4, characterized in that: The mass ratio of the mixed solution to the contrast agent is 5:5 to 9:

1.

6. The method for preparing the intravascular embolic composition according to claim 4, characterized in that: The mass ratio of the total mass of the mixed solution and the contrast agent to the drug is 5:5 to 9:

1.

7. A drug-loaded hydrogel, characterized in that: The intravascular embolization composition prepared by the intravascular embolization composition according to any one of claims 1 to 3 or the preparation method according to any one of claims 4 to 6 is reacted with a solution containing metal ions to form the intravascular embolization composition.

8. The drug-loaded hydrogel according to claim 7, characterized in that: The metal ion-containing solution comprises blood; and / or, The metal ions include one or more of sodium ions, potassium ions, copper ions, magnesium ions, calcium ions, iron ions and aluminum ions.

9. Use of the intravascular embolic composition according to any one of claims 1 to 3, the intravascular embolic composition prepared by the preparation method according to any one of claims 4 to 6, or the drug-loaded hydrogel according to any one of claims 7 to 8 in the preparation of intravascular embolic agents.

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