Embolism microsphere and preparation method thereof

Abstract

The invention provides a preparation method of embolism microspheres. The preparation method comprises the following steps: mixing a polyhydroxy water-soluble high-molecular polymer and a polycarboxyl water-soluble high-molecular polymer to prepare a water phase; adding the water phase into the oil phase, and adding a cross-linking agent containing an aldehyde group to carry out a first cross-linking reaction to obtain first embolization microspheres; and adding an amino-containing cross-linking agent into the aqueous solution dispersed with the first embolism microspheres, and carrying out a second cross-linking reaction to obtain second embolism microspheres. The crosslinking degree can be better controlled by respectively adjusting the two crosslinking reactions, so that the purpose of adjusting the mechanical property of the embolism microsphere is achieved, and the microsphere has good compressibility under the condition that the microsphere has enough mechanical strength.

Description

Technical Field

[0001] The present application relates to the field of medical interventional treatment materials, and in particular to an embolic microsphere and a preparation method thereof. Background Art

[0002] Embolization is an important technique in interventional therapy. It is also called embolization therapy. It is to inject embolic microspheres into the blood vessels supplying the diseased organ through an arterial or venous catheter in a controlled manner to block the blood vessels in order to control bleeding, treat tumors and vascular lesions, and eliminate the function of the diseased organ. In actual use, embolic microspheres need to be injected into the patient's body through a catheter. Therefore, high requirements are placed on how to improve the mechanical strength and compressibility of embolic microspheres. Summary of the invention

[0003] In view of this, the present application provides an embolic microsphere and a preparation method thereof to solve the problems of weak mechanical strength and poor compressibility of the embolic microsphere in the prior art.

[0004] To solve the above technical problems, in the first aspect, the present application provides a method for preparing embolic microspheres, which comprises the following steps: mixing a polyhydroxy water-soluble polymer and a polycarboxyl water-soluble polymer to form an aqueous phase; adding the aqueous phase to an oil phase, and adding a cross-linking agent containing an aldehyde group to carry out a first cross-linking reaction to obtain first embolic microspheres; adding a cross-linking agent containing an amine group to the aqueous solution in which the first embolic microspheres are dispersed to carry out a second cross-linking reaction to obtain second embolic microspheres.

[0005] In some embodiments, the cross-linking agent containing an aldehyde group includes one or more of glutaraldehyde, glyoxal, succinaldehyde, adipaldehyde, and polyethylene glycol dialdehyde.

[0006] In some embodiments, the step of adding an amine-containing crosslinking agent to the aqueous solution in which the first embolic microspheres are dispersed to perform a second crosslinking reaction comprises: adding a catalyst and an amine-containing crosslinking agent to the aqueous solution in which the first embolic microspheres are dispersed to perform a second crosslinking reaction.

[0007] In some embodiments, the catalyst comprises a carbodiimide catalyst; alternatively, the carbodiimide catalyst comprises carbodiimide hydrochloride and N-hydroxysuccinimide.

[0008] In some embodiments, the amine-containing cross-linking agent includes one or more of aminopolyethylene glycol, lysine, spermine, neomycin, polyethyleneimine, propylenediamine and diethylenetriamine.

[0009] In some embodiments, the polyhydroxy water-soluble high molecular polymer includes polyvinyl alcohol and / or hyaluronic acid.

[0010] In some embodiments, the polycarboxyl water-soluble high molecular polymer includes one or more of polyacrylic acid, polymaleic acid, polyaspartic acid and polyglutamic acid.

[0011] In some embodiments, based on the total mass of the aqueous phase, the sum of the mass fractions of the polyhydroxy water-soluble polymer and the polycarboxyl water-soluble polymer is 5% to 15%.

[0012] In some embodiments, the mass ratio of the polyhydroxy water-soluble polymer to the polycarboxyl water-soluble polymer is 1:4 to 4:1.

[0013] In some embodiments, the mass ratio of the oil phase to the water phase is (2-5):1.

[0014] In some embodiments, based on the mass of the aqueous phase, the mass fraction of the cross-linking agent containing an aldehyde group is 1.6% to 3.3%.

[0015] In some embodiments, the mass ratio of the cross-linking agent containing an amine group to the water-soluble high molecular polymer containing multiple carboxyl groups is (1-6):20.

[0016] In some embodiments, the temperature of the first cross-linking reaction is 40° C. to 60° C., the stirring rate is 200 rpm to 500 rpm, and the time of the first cross-linking reaction is 1 h to 3 h.

[0017] In some embodiments, the temperature of the second cross-linking reaction is 20°C to 30°C.

[0018] In some embodiments, the oil phase includes an emulsifier and white oil, and the balance value of the emulsifier ranges from 4 to 7.

[0019] In some embodiments, the aqueous phase is added to the oil phase, and a cross-linking agent containing an aldehyde group is added to carry out a first cross-linking reaction, comprising: adding the aqueous phase to the oil phase, and adding a cross-linking agent containing an aldehyde group and a first acidic reagent to carry out a first cross-linking reaction; optionally, based on the mass of the aqueous phase, the mass fraction of the first acidic reagent is 1.6% to 3.3%; optionally, the first acidic reagent includes hydrochloric acid.

[0020] In some embodiments, adding a catalyst and an amine-containing cross-linking agent to the aqueous solution in which the first embolic microspheres are dispersed to carry out a second cross-linking reaction comprises: adding a second acidic reagent and an amine-containing cross-linking agent to the aqueous solution in which the first embolic microspheres are dispersed to carry out a second cross-linking reaction; optionally, based on the total volume of the aqueous solution, the molar concentration of the second acidic reagent is 10 mmol / L to 100 mmol / L; optionally, the second acidic reagent comprises morpholineethanesulfonic acid.

[0021] In some embodiments, the mass ratio of the catalyst to the polycarboxyl water-soluble high molecular polymer is (1-6):10.

[0022] In a second aspect, the present application provides an embolic microsphere prepared by the embolic microsphere preparation method as described in any one of the above items.

[0023] The beneficial effects of the present application are: providing a method for preparing embolic microspheres, mixing a polyhydroxy water-soluble polymer and a polycarboxyl water-soluble polymer as a skeleton network of the embolic microspheres; and then performing a first cross-linking reaction and a second cross-linking reaction respectively to obtain a second embolic microsphere. The present application can better control the cross-linking degree of the cross-linking reaction by separately regulating the two cross-linking reactions, thereby achieving the purpose of regulating the mechanical properties of the embolic microspheres, so that the microspheres have good compressibility while having sufficient mechanical strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0025] Figure 1 This is a morphological characterization diagram of an embodiment of the embolic microspheres of the present application. DETAILED DESCRIPTION

[0026] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0028] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), and similarly, "multiple groups" refers to more than two (including two groups), and "multiple pieces" refers to more than two (including two pieces), unless otherwise clearly and specifically defined.

[0029] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0031] At present, most embolic microspheres are generally prepared in one pot by reverse suspension polymerization, using water-soluble macromolecular materials and monomer molecules to form embolic microspheres by chemical cross-linking. However, this type of method usually involves several cross-linking and polymerization reactions in the same reaction, and the combination of different monomers and cross-linking agents is relatively complex, making it difficult to control the degree of polymerization and cross-linking, and it is not easy to adjust the mechanical properties of the microspheres.

[0032] An embodiment of the present application provides a method for preparing embolic microspheres, which includes the following steps: mixing a polyhydroxy water-soluble polymer and a polycarboxyl water-soluble polymer to form an aqueous phase; adding the aqueous phase to an oil phase, and adding a cross-linking agent containing an aldehyde group to perform a first cross-linking reaction to obtain first embolic microspheres; adding a cross-linking agent containing an amine group to the aqueous solution in which the first embolic microspheres are dispersed to perform a second cross-linking reaction to obtain second embolic microspheres.

[0033] The preparation method of the embolic microspheres of the embodiment of the present application comprises a water-soluble polymer of polyhydroxyl groups and a water-soluble polymer of polycarboxyl groups in the aqueous phase, so that the two polymers can be preliminarily interlaced to form a staggered skeleton structure. The aqueous phase is added to the oil phase to form an oil-in-water structure; an aldehyde-containing crosslinking agent is used, and its aldehyde group reacts with the hydroxyl group of the water-soluble polymer of polyhydroxyl groups, so that the crosslinking agent containing aldehyde groups and the water-soluble polymer of polyhydroxyl groups undergo a first crosslinking reaction to form a first embolic microsphere with a preliminary network structure. Then, an amine-containing crosslinking agent is added to the aqueous solution of the first embolic microsphere with a preliminary network structure, so that the amine group in the crosslinking agent and the carboxyl group in the water-soluble polymer of polycarboxyl groups undergo an amidation reaction to form a second embolic microsphere with a more compact fixed network structure. In the embodiment of the present application, the aqueous phase contains two polymers with different functional groups, and they respectively include hydroxyl groups and carboxyl groups. The crosslinking agents used in the two crosslinking reactions are different, which is conducive to the regulation of the network structure of the second embolic microsphere. In the embodiment of the present application, two cross-linking reactions are used to better control the degree of cross-linking of the interpenetrating cross-linked network structure, and the embolic microspheres of the interpenetrating cross-linked network structure are obtained, so that the second embolic microspheres are complex and stable cross-linked structures. The implementation method of the present application separates the secondary cross-linking reaction, and the purpose of adjusting the mechanical properties of the embolic microspheres can be achieved by adjusting the two cross-linking reactions separately, so that the microspheres have good compressibility while having sufficient mechanical strength. And the second embolic microspheres obtained, the water-soluble polymer with multiple carboxyl groups with negative charges can adsorb anti-tumor drugs such as doxorubicin, so as to achieve the purpose of drug loading.

[0034] In the embodiment of the present application, the second embolic microsphere is the embolic microsphere finally obtained. Figure 1 The embolic microspheres of this embodiment are relatively uniform spherical.

[0035] Specifically, the preparation method of the embolic microspheres comprises the following steps:

[0036] S1. Preparation of aqueous phase: Two water-soluble polymers, a polyhydroxyl water-soluble polymer and a polycarboxyl water-soluble polymer, are mixed to form an aqueous phase, and a skeleton network is initially formed in the aqueous phase.

[0037] S2. Preparation of oil phase: adding the water phase containing the two water-soluble high molecular polymers dropwise into the oil phase to form an oil-in-water reverse suspension polymerization system.

[0038] S3. First cross-linking: Add a cross-linking agent containing an aldehyde group to the reverse suspension polymerization system, and the cross-linking agent containing an aldehyde group and a water-soluble polymer with multiple hydroxy groups undergo a first cross-linking reaction to obtain a mixed solution containing first embolic microspheres. Use a sieve or a centrifuge to separate the mixed solution into solid and liquid to obtain a solid portion, which contains the first embolic microspheres. Wash the solid portion containing the first embolic microspheres three times with petroleum ether, ethanol, and pure water respectively to obtain first embolic microspheres with a size between 100 μm and 1200 μm. The embodiment of the present application does not limit the washing method of the solid portion containing the first embolic microspheres.

[0039] S4. Second cross-linking: The first embolic microspheres are dispersed in an aqueous solution, and a cross-linking agent containing an amine group is added. The cross-linking agent containing an amine group undergoes a second cross-linking reaction with the polycarboxyl water-soluble high molecular polymer contained in the first embolic microspheres to obtain second embolic microspheres.

[0040] In some embodiments, in the first cross-linking, the cross-linking agent containing aldehyde groups comprises one or more of glutaraldehyde, glyoxal, succinaldehyde, adipaldehyde, and polyethylene glycol dialdehyde. Glutaraldehyde is preferably used in the present embodiment. The cross-linking agent containing aldehyde groups can cross-link the water-soluble high molecular polymer of polyhydroxy. The cross-linking agent containing aldehyde groups plays a cross-linking effect by cross-linking reaction with the hydroxyl in the water-soluble high molecular polymer of polyhydroxy. Wherein can illustrate, glutaraldehyde in the reaction process, the carbonyl of glutaraldehyde and the hydroxyl in the water-soluble high molecular polymer of polyhydroxy form electrophilic reaction, form covalent bond connection, thereby make the water-soluble high molecular polymer of polyhydroxy cross-link, form gel state. Because the cross-linking agent containing aldehyde groups is not easy to dissociate after combining with the water-soluble high molecular polymer of polyhydroxy, therefore has excellent stability.

[0041] In some embodiments, in the second cross-linking, adding a cross-linking agent containing an amine group to the aqueous solution in which the first embolic microspheres are dispersed to carry out a second cross-linking reaction comprises: adding a catalyst and a cross-linking agent containing an amine group to the aqueous solution in which the first embolic microspheres are dispersed to carry out a second cross-linking reaction. Wherein, when the first embolic microspheres are dispersed in the aqueous solution, and the cross-linking agent containing an amine group is added to carry out a second cross-linking reaction with the multi-carboxyl water-soluble high molecular polymer contained in the first embolic microspheres, a catalyst needs to be added simultaneously to catalyze the second cross-linking reaction, so as to increase the reaction rate and reaction degree of the second cross-linking reaction.

[0042] In some embodiments, the catalyst includes a carbodiimide catalyst. The carbodiimide catalyst can be emulsified in water by introducing a hydrophilic group, and thus can be used to catalyze a second crosslinking reaction in an aqueous solution. Alternatively, the carbodiimide catalyst includes carbodiimide hydrochloride and N-hydroxysuccinimide, and this embodiment uses carbodiimide hydrochloride and N-hydroxysuccinimide simultaneously to catalyze the second crosslinking reaction.

[0043] In some embodiments, the mass ratio of the catalyst to the water-soluble polymer with multiple carboxyl groups is (1 to 6):10. Specifically, it can be 1:10, 1.1:10, 2.3:10, 3.2:10, 3.9:10, 4.5:10, 4.9:10, 5.3:10, 5.6:10, 6:10. Or it can be a range formed by any two of the above values, such as 1.1:10 to 3.2:10, 3.2:10 to 4.9:10, 4.9:10 to 5.6:10, etc. In the second cross-linking reaction, the catalyst and the cross-linking agent containing an amine group are used simultaneously. When the mass ratio of the catalyst to the water-soluble polymer with multiple carboxyl groups is in the range of (1 to 6):10, the degree of cross-linking reaction can be better catalyzed.

[0044] In some embodiments, the cross-linking agent containing an amine group includes one or more of aminopolyethylene glycol, lysine, spermine, neomycin, polyethyleneimine, propylenediamine and diethylenetriamine. The cross-linking agent containing an amine group is a polyamine compound, which is a compound with two or more amino groups. The polyamine compound has high biocompatibility, and the embolic microspheres obtained after the second cross-linking reaction are highly compatible with the human body after being implanted into the human body. In this embodiment, during the second cross-linking, the charge density of the embolic microsphere load can be changed by selecting the type and amount of the cross-linking agent containing an amine group, thereby adjusting the drug loading capacity of the embolic microspheres.

[0045] In some embodiments, the polyhydroxy water-soluble high molecular polymer includes polyvinyl alcohol and / or hyaluronic acid. Among them, polyvinyl alcohol has good biocompatibility and mechanical properties, polyvinyl alcohol does not cause allergic reactions, and the polyvinyl alcohol main chain as a skeleton can also improve the mechanical properties of the embolic microspheres. When hyaluronic acid is at a higher concentration, it can form a complex network structure due to its intermolecular interaction, and its aqueous solution has significant viscoelasticity, which can also improve the mechanical properties of the embolic microspheres.

[0046] In some embodiments, the polycarboxyl water-soluble high molecular polymer includes one or more of polyacrylic acid, polymaleic acid, polyaspartic acid and polyglutamic acid.

[0047] In some embodiments, based on the total mass of the aqueous phase, the sum of the mass fractions of the polyhydroxy water-soluble polymer and the polycarboxyl water-soluble polymer is 5% to 15%. Specifically, it can be 5.1%, 6.5%, 7.4%, 8.9%, 9.7%, 12%, 13.5%, 14.7%, or the above-mentioned range, for example, it can be 5.5% to 11%, 6.1% to 14.9%, 7% to 12%, 8% to 10%, 9% to 14.9%, 9.2% to 10.2%, 12% to 14.5%, 13% to 14.7%. If the content of the two water-soluble polymers is low, the embolic microspheres are not easy to form; if the content is too high, the embolic microspheres are too rigid, affecting the compression performance. The sum of the mass fractions of the polyhydroxy water-soluble polymer and the polycarboxyl water-soluble polymer is within this ratio range, so that the subsequently formed embolic microspheres can have both excellent mechanical properties and good compressibility.

[0048] In some embodiments, the mass ratio of the polyhydroxy water-soluble polymer to the polycarboxyl water-soluble polymer is 1:4 to 4:1. The polyhydroxy water-soluble polymer and the polycarboxyl water-soluble polymer are mixed to form an aqueous phase, and the mass ratio of the polyhydroxy water-soluble polymer to the polycarboxyl water-soluble polymer is 1:4 to 4:1. Specifically, it can be 1:4, 1:3, 3:7, 2:3, 11:9, 13:7, 39:11, 4:1.

[0049] In some embodiments, the mass ratio of the oil phase to the water phase is (2-5):1. The water phase containing two water-soluble polymers is added dropwise to the oil phase to form an oil-in-water reverse suspension polymerization system. When the mass ratio of the oil phase to the water phase is (2-5):1, it is more suitable for forming an oil-in-water system. Specifically, it can be 2.1:1, 2.8:1, 3.1:1, 3.4:1, 3.9:1, 4.2:7, 4.7:11, 4.9:1.

[0050] In some embodiments, based on the mass of the aqueous phase, the mass fraction of the cross-linking agent containing an aldehyde group is 1.6% to 3.3%, and can be specifically 1.7%, 1.81%, 1.86%, 1.9%, 1.96%, 2.4%, 2.78%, or 3.04%.

[0051] In some embodiments, the mass ratio of the cross-linking agent containing an amine group to the water-soluble polymer with multiple carboxyl groups is (1-6):20. Specifically, it can be 1:20, 2.1:20, 2.8:20, 3:20, 3.7:20, 4.5:20, 5.3:20, 5.6:20. If the content of the cross-linking agent containing an amine group is low, the second cross-linking degree of the embolic microspheres is insufficient; if the content is too high, the rigidity of the embolic microspheres is too strong, which affects the compression performance and causes a waste of the cross-linking agent. When the mass ratio of the cross-linking agent containing an amine group to the water-soluble polymer with multiple carboxyl groups is in the range of (1-6):20, the embolic microspheres formed by the second cross-linking have good mechanical properties.

[0052] In some embodiments, the temperature of the first cross-linking reaction is 40°C to 60°C, the stirring rate is 200rpm to 500rpm, and the time of the first cross-linking reaction is 1h to 3h. Specifically, in step S2 and step S3, at a stirring rate of 200rpm to 500rpm, the water phase is added dropwise to the oil phase to form an oil-in-water reverse suspension polymerization system; after the water phase is added dropwise, the reverse suspension polymerization system is heated to 40 to 60°C, and then a cross-linking agent containing an aldehyde group is added to carry out the first cross-linking reaction, and the temperature and stirring are maintained for 1h to 3h; after the reaction is completed, a mixed solution containing the first embolic microspheres is obtained; the mixed solution is separated from the solid by a sieve or a centrifuge to obtain a solid part, which contains the first embolic microspheres. The solid part containing the first embolic microspheres is washed three times with petroleum ether, ethanol, and pure water respectively to obtain the first embolic microspheres with a size between 100μm and 1200μm.

[0053] In some embodiments, the temperature of the second cross-linking reaction is 20° C. to 30° C. Specifically, in the second cross-linking, a catalyst is added to the aqueous solution in which the first embolic microspheres are dispersed, and the reaction is stirred at 20° C. to 30° C. for 0.5 h, and then an amine-containing cross-linking agent is added for a second cross-linking reaction, and the reaction is stirred at 20° C. to 30° C. for 3 h to 5 h to obtain a mixed solution containing the second embolic microspheres, and finally the mixed solution containing the second embolic microspheres is washed with pure water 3 times to obtain the second embolic microspheres.

[0054] In some embodiments, the oil phase includes an emulsifier and white oil, and the balance value (HLB value) of the emulsifier ranges from 4 to 7. Specifically, the oil phase is composed of an emulsifier and white oil, and the mass fraction of the emulsifier and the white oil is 2% to 6%. The emulsifier is composed of one or more of Span-60, Span-65, Span-80, Tween-60, Tween-65, and Tween-80. And the average HLB value is required to be between 4 and 7 in the composite system of multiple emulsifiers. The HLB value generally refers to the balance value, that is, the hydrophilic-lipophilic balance, which refers to the balance relationship between the hydrophilic group and the lipophilic group of the surfactant in size and strength. The average HLB value is between 4 and 7, which is more suitable for the subsequent formation of an oil-in-water system.

[0055] In some embodiments, the aqueous phase is added to the oil phase, and a cross-linking agent containing an aldehyde group is added to carry out a first cross-linking reaction, including: adding the aqueous phase to the oil phase, and adding a cross-linking agent containing an aldehyde group and a first acidic reagent to carry out a first cross-linking reaction; optionally, based on the mass of the aqueous phase, the mass fraction of the first acidic reagent is 1.6% to 3.3%; optionally, the first acidic reagent includes hydrochloric acid.

[0056] Specifically, in the first crosslinking, the water phase is added dropwise to the oil phase to form an oil-in-water reverse suspension polymerization system; after the water phase is added dropwise, the reverse suspension polymerization system is heated to 40°C to 60°C, and then the crosslinking agent containing an aldehyde group and the first acidic reagent are added to carry out the first crosslinking reaction, and the temperature and stirring are maintained, and the reaction time is 1h to 3h; after the reaction is completed, a mixed solution containing the first embolic microspheres is obtained; the mixed solution is separated into solid and liquid by a sieve or a centrifuge and the like to obtain a solid part, which contains the first embolic microspheres. The solid part containing the first embolic microspheres is washed three times with petroleum ether, ethanol, and pure water respectively to obtain the first embolic microspheres. Among them, the mass fraction of the first acidic reagent is 1.6% to 3.3%; optionally, the first acidic reagent includes hydrochloric acid. The first acidic reagent is used to make the first crosslinking reaction react in an acidic environment.

[0057] In some embodiments, adding a catalyst and a cross-linking agent containing an amine group to the aqueous solution in which the first embolic microspheres are dispersed to carry out a second cross-linking reaction comprises: adding a second acidic reagent and a cross-linking agent containing an amine group to the aqueous solution in which the first embolic microspheres are dispersed to carry out a second cross-linking reaction; optionally, based on the total volume of the aqueous solution, the molar concentration of the second acidic reagent is 10 mmol / L to 100 mmol / L; optionally, the second acidic reagent comprises morpholineethanesulfonic acid.

[0058] Specifically, in the second cross-linking, the first embolic microspheres are dispersed in an aqueous solution, a second acidic reagent is added to the aqueous solution, and the molar concentration of the second acidic reagent is 10 mmol / L to 100 mmol / L based on the total volume of the aqueous solution; a catalyst is added to the acidic aqueous solution in which the first embolic microspheres are dispersed, and the reaction is stirred at 20°C to 30°C for 0.5 hours, and then an amine-containing cross-linking agent is added for a second cross-linking reaction, and the reaction is stirred at 20°C to 30°C for 3 hours to 5 hours to obtain a mixed solution containing the second embolic microspheres, and finally the mixed solution containing the second embolic microspheres is washed with pure water for 3 times to obtain the second embolic microspheres. Wherein, the second acidic reagent includes morpholineethanesulfonic acid.

[0059] According to some embodiments of the present application, an embolic microsphere is provided. The embolic microsphere is prepared by any of the above-mentioned methods for preparing the embolic microsphere.

[0060] In the above embodiments, the preparation method of the embolic microspheres provided by the present application performs two cross-linking reactions separately, and finally obtains embolic microspheres with an interpenetrating cross-linked network structure. By adjusting the two cross-linking reactions separately, the cross-linking degree of the interpenetrating cross-linked network structure can be better controlled, thereby achieving the purpose of adjusting the mechanical properties of the embolic microspheres, so that the microspheres have good compressibility while having sufficient mechanical strength. And during the second cross-linking, by selecting the type and amount of the cross-linking agent containing an amine group, the charge density of the embolic microsphere load can be changed, thereby adjusting the drug loading capacity of the embolic microspheres.

[0061] The beneficial effects of the present application are further illustrated below in conjunction with embodiments.

[0062] In order to make the technical problems, technical solutions and beneficial effects solved by the embodiments of the present application clearer, the following will be further described in detail with reference to the embodiments and the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its applications. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0063] Example 1

[0064] The method for preparing embolic microspheres comprises:

[0065] Preparation of aqueous phase: Dissolve 1 g of polyvinyl alcohol in 10 mL of pure water, and dissolve 1 g of polyacrylic acid in 10 mL of pure water, mix the two and stir evenly.

[0066] Preparation of oil phase: Add 0.22 g Tween 80 and 1.78 g Span 80 to 78 g liquid paraffin and mix well (HLB=5.5).

[0067] First cross-linking: Place the oil phase in an ice bath, cool it down sufficiently, and then add the water phase component dropwise to the oil phase component under stirring at 300 rpm. After mixing, heat it to 60°C, add 1 mL of 50% glutaraldehyde aqueous solution, stir for 30 min, then add 1 mL of 1 mmol / L hydrochloric acid, and continue to react for 2 h. Remove the solvent, wash with petroleum ether, ethanol, and pure water three times each to obtain the first embolic microspheres.

[0068] Second cross-linking: The first embolic microspheres were dispersed in 20 mL of 50 mmol / L morpholineethanesulfonic acid aqueous solution, and the catalysts: 156 mg of N-hydroxysuccinimide and 260 mg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added to the mixed solution. After stirring and mixing at 25°C for 30 min, 100 mg of aminopolyethylene glycol was added and stirred for 4 h. The second embolic microspheres were washed three times with pure water to obtain the second embolic microspheres.

[0069] Embodiment 2:

[0070] Preparation of aqueous phase: Dissolve 1 g of polyvinyl alcohol in 10 mL of pure water, and dissolve 1 g of polyacrylic acid in 10 mL of pure water, mix the two and stir evenly.

[0071] Preparation of oil phase: Add 0.22 g Tween 80 and 1.78 g Span 80 to 78 g white oil and mix well (HLB=5.5).

[0072] First cross-linking: Place the oil phase in an ice bath, cool it down sufficiently, and then add the water phase component dropwise to the oil phase component under stirring at 300 rpm. After mixing, heat it to 60°C, add 1 mL of 50% glutaraldehyde aqueous solution, stir for 30 min, then add 1 mL of 1 mmol / L hydrochloric acid, and continue to react for 2 h. Remove the solvent, wash with petroleum ether, ethanol, and pure water three times each to obtain the first embolic microspheres.

[0073] Second cross-linking: The first embolic microspheres were dispersed in 20 mL of 50 mmol / L morpholineethanesulfonic acid aqueous solution, and the catalysts: 156 mg of N-hydroxysuccinimide and 260 mg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added to the mixed solution. After stirring and mixing at 25°C for 30 min, 100 mg of lysine was added and stirred for 4 h. The microspheres were washed three times with pure water to obtain the second embolic microspheres.

[0074] Example 3

[0075] Preparation of aqueous phase: Dissolve 1g polyvinyl alcohol in 10mL pure water, and dissolve 1g polyacrylic acid in 10mL pure water, mix the two and stir evenly;

[0076] Preparation of oil phase: Add 0.22g Tween 80 and 1.78g Span 80 to 78g white oil and mix well (HLB=5.5);

[0077] First cross-linking: Place the oil phase in an ice bath, cool it down sufficiently, and then add the water phase component dropwise to the oil phase component under stirring at 300 rpm. After mixing, heat it to 60°C, add 1 mL of 50% glutaraldehyde aqueous solution, stir for 30 min, then add 1 mL of 1 mmol / L hydrochloric acid, and continue to react for 2 h. Remove the solvent, wash with petroleum ether, ethanol, and pure water three times each to obtain the first embolic microspheres.

[0078] Second cross-linking: The first embolic microspheres were dispersed in 20 mL of 50 mmol / L morpholineethanesulfonic acid aqueous solution, and the catalysts: 156 mg of N-hydroxysuccinimide and 260 mg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added to the mixed solution. After stirring and mixing at 25°C for 30 min, 200 mg of aminopolyethylene glycol was added and stirred for 4 h. The second embolic microspheres were washed three times with pure water to obtain the second embolic microspheres.

[0079] Example 4

[0080] Preparation of aqueous phase: Dissolve 1g polyvinyl alcohol in 10mL pure water, and dissolve 1g polymaleic acid in 10mL pure water, mix the two and stir evenly;

[0081] Preparation of oil phase: Add 0.22g Tween 80 and 1.78g Span 80 to 78g white oil and mix well (HLB=5.5);

[0082] First cross-linking: Place the oil phase in an ice bath, cool it down sufficiently, and then add the water phase component dropwise to the oil phase component under stirring at 300 rpm. After mixing, heat it to 60°C, add 1 mL of 50% glutaraldehyde aqueous solution, stir for 30 min, then add 1 mL of 1 mmol / L hydrochloric acid, and continue to react for 2 h. Remove the solvent, wash with petroleum ether, ethanol, and pure water three times each to obtain the first embolic microspheres.

[0083] Second cross-linking: The first embolic microspheres were dispersed in 20 mL of 50 mmol / L morpholineethanesulfonic acid aqueous solution, and the catalysts: 156 mg of N-hydroxysuccinimide and 260 mg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added to the mixed solution. After stirring and mixing at 25°C for 30 min, 100 mg of aminopolyethylene glycol was added and stirred for 4 h. The second embolic microspheres were washed three times with pure water to obtain the second embolic microspheres.

[0084] Example 5

[0085] Preparation of aqueous phase: Dissolve 1g hyaluronic acid in 10mL pure water, and dissolve 1g polyaspartic acid in 10mL pure water, mix the two and stir evenly;

[0086] Preparation of oil phase: Add 0.22g Tween 80 and 1.78g Span 80 to 78g white oil and mix well (HLB=5.5);

[0087] First cross-linking: Place the oil phase in an ice bath, cool it down sufficiently, and then add the water phase component dropwise to the oil phase component under stirring at 300 rpm. After mixing, heat it to 60°C, add 1 mL of 50% glutaraldehyde aqueous solution, stir for 30 min, then add 1 mL of 1 mmol / L hydrochloric acid, and continue to react for 2 h. Remove the solvent, wash with petroleum ether, ethanol, and pure water three times each to obtain the first embolic microspheres.

[0088] Second cross-linking: The first embolic microspheres were dispersed in 20 mL of 50 mmol / L morpholineethanesulfonic acid aqueous solution, and the catalysts: 156 mg of N-hydroxysuccinimide and 260 mg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added to the mixed solution. After stirring and mixing at 25°C for 30 min, 100 mg of aminopolyethylene glycol was added and stirred for 4 h. The second embolic microspheres were washed three times with pure water to obtain the second embolic microspheres.

[0089] Example 6

[0090] Preparation of aqueous phase: Dissolve 0.4 g hyaluronic acid in 10 mL pure water, and dissolve 1.6 g polyaspartic acid in 10 mL pure water, mix the two and stir evenly;

[0091] Preparation of oil phase: Add 0.22g Tween 80 and 1.78g Span 80 to 78g white oil and mix well (HLB=5.5);

[0092] First cross-linking: Place the oil phase in an ice bath, cool it down sufficiently, and then add the water phase component dropwise to the oil phase component under stirring at 300 rpm. After mixing, heat it to 60°C, add 0.7 mL of 50% glutaraldehyde aqueous solution, stir for 30 min, then add 1 mL of 0.7 mmol / L hydrochloric acid, and continue to react for 2 h. Remove the solvent, wash with petroleum ether, ethanol, and pure water three times each to obtain the first embolic microspheres.

[0093] Second cross-linking: The first embolic microspheres were dispersed in 20 mL of 50 mmol / L morpholineethanesulfonic acid aqueous solution, and the catalysts: 156 mg of N-hydroxysuccinimide and 260 mg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added to the mixed solution. After stirring and mixing at 25°C for 30 min, 100 mg of aminopolyethylene glycol was added and stirred for 4 h. The second embolic microspheres were washed three times with pure water to obtain the second embolic microspheres.

[0094] Example 7

[0095] The method for preparing embolic microspheres comprises:

[0096] Preparation of aqueous phase: Dissolve 1.6 g of polyvinyl alcohol in 10 mL of pure water, and dissolve 0.4 g of polyacrylic acid in 10 mL of pure water, mix the two, and stir evenly.

[0097] Preparation of oil phase: Add 0.22 g Tween 80 and 1.78 g Span 80 to 78 g white oil and mix well (HLB=5.5).

[0098] First cross-linking: Place the oil phase in an ice bath, cool it down sufficiently, and then add the water phase component dropwise to the oil phase component under stirring at 300 rpm. After mixing, heat it to 60°C, add 1.3 mL of 50% glutaraldehyde aqueous solution, stir for 30 min, then add 1.3 mL of 1 mmol / L hydrochloric acid, and continue to react for 2 h. Remove the solvent, wash with petroleum ether, ethanol, and pure water three times each to obtain the first embolic microspheres.

[0099] Second cross-linking: The first embolic microspheres were dispersed in 20 mL of 50 mmol / L morpholineethanesulfonic acid aqueous solution, and the catalysts: 156 mg of N-hydroxysuccinimide and 260 mg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added to the mixed solution. After stirring and mixing at 25°C for 30 min, 100 mg of aminopolyethylene glycol was added and stirred for 4 h. The second embolic microspheres were washed three times with pure water to obtain the second embolic microspheres.

[0100] Example 8

[0101] The method for preparing embolic microspheres comprises:

[0102] Preparation of aqueous phase: Dissolve 1.5 g of polyvinyl alcohol in 8.5 mL of pure water, and dissolve 1.5 g of polyacrylic acid in 8.5 mL of pure water, mix the two, and stir evenly.

[0103] Preparation of oil phase: Add 0.22 g Tween 80 and 1.78 g Span 80 to 78 g white oil and mix well (HLB=5.5).

[0104] First cross-linking: Place the oil phase in an ice bath, cool it down sufficiently, and then add the water phase component dropwise to the oil phase component under stirring at 300 rpm. After mixing, heat it to 60°C, add 1.3 mL of 50% glutaraldehyde aqueous solution, stir for 30 min, then add 1.3 mL of 1 mmol / L hydrochloric acid, and continue to react for 2 h. Remove the solvent, wash with petroleum ether, ethanol, and pure water three times each to obtain the first embolic microspheres.

[0105] Second cross-linking: The first embolic microspheres were dispersed in 20 mL of 50 mmol / L morpholineethanesulfonic acid aqueous solution, and the catalysts: 156 mg of N-hydroxysuccinimide and 260 mg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added to the mixed solution. After stirring and mixing at 25°C for 30 min, 100 mg of aminopolyethylene glycol was added and stirred for 4 h. The second embolic microspheres were washed three times with pure water to obtain the second embolic microspheres.

[0106] Example 9

[0107] The method for preparing embolic microspheres comprises:

[0108] Preparation of aqueous phase: Dissolve 1 g of polyvinyl alcohol in 10 mL of pure water, and dissolve 1 g of polyacrylic acid in 10 mL of pure water, mix the two and stir evenly.

[0109] Preparation of oil phase: Add 0.22 g Tween 80 and 1.78 g Span 80 to 78 g white oil and mix well (HLB=5.5).

[0110] First cross-linking: Place the oil phase in an ice bath, cool it down sufficiently, and then add the water phase component dropwise to the oil phase component under stirring at 300 rpm. After mixing, heat it to 60°C, add 1 mL of 50% glutaraldehyde aqueous solution, stir for 30 min, then add 1 mL of 1 mmol / L hydrochloric acid, and continue to react for 2 h. Remove the solvent, wash with petroleum ether, ethanol, and pure water three times each to obtain the first embolic microspheres.

[0111] Second cross-linking: The first embolic microspheres were dispersed in 20 mL of 50 mmol / L morpholineethanesulfonic acid aqueous solution, and the catalysts: 156 mg of N-hydroxysuccinimide and 260 mg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added to the mixed solution. After stirring and mixing at 25°C for 30 min, 300 mg of aminopolyethylene glycol was added and stirred for 4 h. The second embolic microspheres were washed three times with pure water to obtain the second embolic microspheres.

[0112] Comparative Example 1

[0113] The method for preparing embolic microspheres comprises:

[0114] Preparation of aqueous phase: Dissolve 2 g of polyvinyl alcohol in 20 mL of pure water and stir evenly.

[0115] Preparation of oil phase: Add 0.22 g Tween 80 and 1.78 g Span 80 to 78 g white oil and mix well (HLB=5.5).

[0116] Cross-linking: Place the oil phase in an ice bath, cool it down sufficiently, and then add the water phase component dropwise to the oil phase component under stirring at 300 rpm. After mixing, heat it to 60°C, add 1.3 mL of 50% glutaraldehyde aqueous solution, stir for 30 min, then add 1.3 mL of 1 mmol / L hydrochloric acid, and continue to react for 2 h. Remove the solvent, wash with petroleum ether, ethanol, and pure water three times each to obtain embolic microspheres.

[0117] The embolic microspheres 1 to 10 obtained in the above Examples 1 to 9 and Comparative Example 1 were subjected to a compression resistance test, and the results are shown in Table 1.

[0118] Compression performance test method:

[0119] The wet embolic microspheres were spread out into a single layer on the sample stage of a texture analyzer, and the microspheres were compressed to 50% of their particle size using a texture analyzer, and the load data of the texture analyzer were recorded.

[0120]

[0121]

[0122] It can be seen from the relevant data in Table 1 that the compressive resistance of the embolic microspheres of Examples 1 to 9 is stronger than that of Comparative Example 1, indicating that the preparation method provided by the present application can be used to prepare embolic microspheres, and the cross-linking degree of the cross-linking reaction can be better controlled, so as to achieve the purpose of adjusting the mechanical properties of the embolic microspheres, so that the microspheres have sufficient mechanical strength and good compressibility.

[0123] The above are only implementation methods of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for preparing embolic microspheres, characterized in that: It includes the following steps: Mixing a polyhydroxyl water-soluble high molecular polymer and a polycarboxyl water-soluble high molecular polymer to form an aqueous phase; adding the aqueous phase to the oil phase, and adding a cross-linking agent containing an aldehyde group to perform a first cross-linking reaction to obtain first embolic microspheres; A cross-linking agent containing an amine group is added to the aqueous solution in which the first embolic microspheres are dispersed to carry out a second cross-linking reaction to obtain second embolic microspheres.

2. The method for preparing embolic microspheres according to claim 1, characterized in that: The cross-linking agent containing aldehyde groups includes one or more of glutaraldehyde, glyoxal, succinaldehyde, adipaldehyde, and polyethylene glycol dialdehyde.

3. The method for preparing embolic microspheres according to claim 1, characterized in that: The step of adding an amine-containing crosslinking agent to the aqueous solution in which the first embolic microspheres are dispersed to perform a second crosslinking reaction comprises: A catalyst and an amine-containing cross-linking agent are added to the aqueous solution in which the first embolic microspheres are dispersed to carry out a second cross-linking reaction.

4. The method for preparing embolic microspheres according to claim 3, characterized in that: The catalyst comprises a carbodiimide catalyst; Optionally, the carbodiimide catalyst includes carbodiimide hydrochloride and N-hydroxysuccinimide.

5. The method for preparing embolic microspheres according to claim 1 or 3, characterized in that: The cross-linking agent containing amine groups includes one or more of aminopolyethylene glycol, lysine, spermine, neomycin, polyethyleneimine, propylenediamine and diethylenetriamine.

6. The method for preparing embolic microspheres according to claim 1, characterized in that: The polyhydroxy water-soluble high molecular polymer includes polyvinyl alcohol and / or hyaluronic acid.

7. The method for preparing embolic microspheres according to claim 1, characterized in that: The polycarboxyl water-soluble high molecular polymer includes one or more of polyacrylic acid, polymaleic acid, polyaspartic acid and polyglutamic acid.

8. The method for preparing embolic microspheres according to claim 1, characterized in that: Based on the total mass of the aqueous phase, the sum of the mass fractions of the polyhydroxy water-soluble high molecular polymer and the polycarboxyl water-soluble high molecular polymer is 5% to 15%.

9. The method for preparing embolic microspheres according to claim 1 or 8, characterized in that: The mass ratio of the polyhydroxy water-soluble high molecular polymer to the polycarboxyl water-soluble high molecular polymer is 1:4 to 4:

1.

10. The method for preparing embolic microspheres according to claim 1, characterized in that: The mass ratio of the oil phase to the water phase is (2-5):

1.

11. The method for preparing embolic microspheres according to claim 1 or 2, characterized in that: Based on the mass of the water phase, the mass fraction of the cross-linking agent containing an aldehyde group is 1.6% to 3.3%.

12. The method for preparing embolic microspheres according to claim 1, characterized in that: The mass ratio of the cross-linking agent containing amino groups to the water-soluble high molecular polymer containing multiple carboxyl groups is (1-6):

20.

13. The method for preparing embolic microspheres according to claim 1, characterized in that: The temperature of the first cross-linking reaction is 40° C. to 60° C., the stirring rate is 200 rpm to 500 rpm, and the time of the first cross-linking reaction is 1 h to 3 h.

14. The method for preparing embolic microspheres according to claim 1, characterized in that: The temperature of the second cross-linking reaction is 20°C to 30°C.

15. The method for preparing embolic microspheres according to claim 1, characterized in that: The oil phase includes an emulsifier and white oil, and the balance value HLB of the emulsifier ranges from 4 to 7.

16. The method for preparing embolic microspheres according to claim 1, characterized in that: The step of adding the water phase to the oil phase and adding a cross-linking agent containing an aldehyde group to perform a first cross-linking reaction comprises: Adding the water phase to the oil phase, and adding a cross-linking agent containing an aldehyde group and a first acidic reagent to perform a first cross-linking reaction; Optionally, based on the mass of the aqueous phase, the mass fraction of the first acidic reagent is 1.6% to 3.3%; Optionally, the first acidic reagent includes hydrochloric acid.

17. The method for preparing embolic microspheres according to claim 1, characterized in that: Adding a catalyst and an amine-containing crosslinking agent to the aqueous solution in which the first embolic microspheres are dispersed to perform a second crosslinking reaction comprises: Adding a second acidic reagent and a cross-linking agent containing an amine group to the aqueous solution in which the first embolic microspheres are dispersed to carry out a second cross-linking reaction; Optionally, based on the total volume of the aqueous solution, the molar concentration of the second acidic reagent is 10 mmol / L to 100 mmol / L; Optionally, the second acidic reagent comprises morpholineethanesulfonic acid.

18. The method for preparing embolic microspheres according to claim 3 or 4, characterized in that: The mass ratio of the catalyst to the polycarboxyl water-soluble high molecular polymer is (1-6):

10.

19. An embolic microsphere, characterized in that: The embolic microspheres are prepared by the preparation method of the embolic microspheres according to any one of claims 1 to 18.

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