Supramolecular composite microsphere as well as preparation method and application thereof

Abstract

The embodiment of the invention provides a supramolecular composite microsphere as well as a preparation method and application thereof, and relates to the technical field of embolism microspheres. The preparation method of the supramolecular composite microspheres comprises the following steps that a water-phase solution and an oil-phase solution are mixed to form a water-in-oil reversed-phase suspension polymerization system, the water-phase solution comprises a water-soluble anionic monomer, a cross-linking agent, a water-soluble pore-forming agent, an initiator and water, and anionic hydrogel microspheres with pore channels are obtained through reaction; and mixing the cationic supramolecular compound with the anionic hydrogel microspheres, so that the cationic supramolecular compound is loaded on the pore channels and the surfaces of the anionic hydrogel microspheres under the action of charges to obtain the supramolecular composite microspheres. According to the preparation method of the supramolecular composite microsphere, the microsphere preparation process has controllability and convenience, and the prepared composite microsphere has excellent broad-spectrum drug loading capacity, has excellent hydrophilicity and mechanical properties, and is suitable for various application scenes such as TACE treatment and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of embolization microspheres, in particular to a supramolecular composite microsphere and a preparation method and application thereof. BACKGROUND

[0002] At present, drug-loaded hydrogel microspheres have been widely used in many fields due to their unique physical and chemical properties and excellent biocompatibility: in the medical field, hydrogel microspheres can be used as drug delivery carriers; in the field of tissue engineering and regenerative medicine, hydrogel microspheres can be used as cell carriers; in the field of antibiosis, hydrogel microspheres can efficiently store antibacterial drugs; in the industrial field, hydrogel microspheres can be used as immobilized enzyme carriers.

[0003] At present, commercially available drug-loaded hydrogel microspheres are mainly anionic microspheres, which can realize efficient loading and slow release of small-molecule cationic drugs (such as doxorubicin hydrochloride and irinotecan hydrochloride) through charge interaction and ion exchange process, but cannot realize efficient loading of neutral molecule drugs and macromolecular drugs. In addition, some composite microspheres formed by introducing supramolecular host compounds such as cyclodextrin into the microspheres have been reported, which show certain broad-spectrum drug loading capacity for non-cationic drugs, but the introduction of supramolecular host compounds into the microspheres is usually before or during the preparation of the microspheres, which greatly limits the controllability and convenience of the microsphere preparation. Moreover, the composite microspheres have the problem of poor hydrophilicity and mechanical properties due to improper introduction of supramolecular compounds, which further affects the delivery and use of the composite microspheres. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a supramolecular composite microsphere and a preparation method and application thereof, the microsphere preparation process has controllability and convenience, and the prepared composite microspheres have excellent broad-spectrum drug loading capacity, excellent loading capacity and slow release effect for various macromolecular, small-molecular, cationic and non-cationic drugs, and excellent hydrophilicity and mechanical properties, which are suitable for various application scenarios such as TACE treatment.

[0005] In a first aspect, the embodiments of the present application provide a preparation method of a supramolecular composite microsphere, which comprises the following steps: mixing an aqueous solution and an oil solution to form a water-in-oil reverse suspension polymerization system, the aqueous solution comprising a water-soluble anionic monomer, a crosslinking agent, a water-soluble pore-forming agent, an initiator and water, and the oil solution comprising an organic solvent and a dispersant, to obtain an anionic hydrogel microsphere with pores; mixing a cationic supramolecular compound with the anionic hydrogel microsphere, so that the cationic supramolecular compound is loaded on the pores and surface of the anionic hydrogel microsphere through charge interaction, to obtain a supramolecular composite microsphere.

[0006] In the above technical solution, anionic hydrogel microspheres are first prepared by reacting and polymerizing them into spheres through a water-in-oil reverse suspension polymerization system. The aqueous solution contains water-soluble anionic monomers and crosslinking agents. These three components copolymerize under the action of an initiator to form the hydrogel matrix framework of the anionic hydrogel microspheres. A water-soluble pore-forming agent is also added to the aqueous solution. As the water-soluble pore-forming agent is removed, it is used to create interconnected channels (connecting the surface and the interior) in the microspheres, resulting in anionic hydrogel microspheres with channels. Then, through charge interaction, cationic supramolecular compounds are efficiently and stably loaded onto the channels and surface of the anionic hydrogel microspheres to obtain supramolecular composite microspheres.

[0007] Because this technology involves first preparing the microsphere matrix, the microsphere preparation process is controllable and convenient. Furthermore, by adding a water-soluble pore-forming agent during the cross-linking polymerization of water-soluble monomers, the microspheres possess sufficient, interconnected large-diameter channels and an ultra-high specific surface area. This ensures that an effective amount of cationic supramolecular compounds are adsorbed and assembled onto the surface and inner walls of the pores through charge interactions, thereby leveraging the cationic supramolecular compounds and pores to achieve excellent broad-spectrum drug loading capacity. Specifically, the large-diameter channels in the microspheres, in addition to loading large-molecule drugs, can also enhance the loading capacity and sustained-release effect through host-guest interactions. Furthermore, the large-diameter channels and ultra-high specific surface area of ​​the microspheres further enhance the drug loading capacity and sustained-release effect for cationic small-molecule drugs. Moreover, because the microspheres are loaded with an effective amount of cationic supramolecular compounds, they can form specific adsorption of non-cationic small-molecule drugs through host-guest interactions, significantly increasing the drug loading capacity and sustained-release effect. Therefore, the supramolecular composite microspheres prepared in this application have excellent broad-spectrum drug loading capacity, and have excellent loading capacity and sustained release effect for various macromolecules, small molecules, cationic and non-cationic drugs. At the same time, they retain the excellent hydrophilicity and mechanical properties of hydrogel microspheres, making them suitable for various application scenarios such as TACE therapy.

[0008] In one possible implementation, the method for preparing the aqueous phase solution includes: preparing an aqueous solution of a water-soluble anionic monomer by mixing a water-soluble anionic monomer and water; neutralizing the solution by slowly adding an alkaline solution dropwise under an ice-water bath; then adding the crosslinking agent and the water-soluble pore-forming agent; after complete dissolution, adding the initiator; and mixing thoroughly to obtain the aqueous phase solution. The method for preparing the oil phase solution includes: mixing an organic solvent and a dispersant; stirring thoroughly to completely dissolve the dispersant to obtain the oil phase solution.

[0009] In one possible implementation, the water-soluble anionic monomer comprises one or more of the following: a carboxylic acid compound having both a carboxyl group and a double bond, a carboxylate compound having both a sulfonic acid group and a double bond, and a sulfonate compound having both a sulfonate group and a double bond; and / or, the crosslinking agent comprises one or more of the following: N,N-methylenebisacrylamide, N-(2,2-dimethoxyethyl)-2-acrylamide-modified polyvinyl alcohol, and polyethylene glycol bisacrylamide.

[0010] In one possible implementation, the aqueous solution further includes a water-soluble nonionic monomer; optionally, the water-soluble nonionic monomer includes one or more of vinylimidazole, N-vinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, and N-isopropylacrylamide.

[0011] In one possible implementation, the water-soluble pore-forming agent comprises one or more of polyethylene glycol, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol monomethyl ether, polyethylene glycol dimethyl ether, polypropylene glycol, and polyoxyethylene-polyoxypropylene copolymer; and / or, the amount of the water-soluble pore-forming agent is 10-50 wt% of the total mass of all functional monomers; and / or, the initiator comprises one or more of sodium persulfate, potassium persulfate, ammonium persulfate, benzoyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, and azodialkylimidazoline salt.

[0012] In the above technical solution, a suitable water-soluble pore-forming agent is added during the process of cross-linking polymerization of water-soluble monomers to form microspheres. Since the water-soluble pore-forming agent has good solubility in both water and organic solvents, it is easy to remove in the post-processing. As the water-soluble pore-forming agent is removed, channels with internal and external connecting tubes will be generated in the microspheres.

[0013] In one possible implementation, the organic solvent includes one or more of butyl acetate, ethyl acetate, liquid paraffin, dimethyl silicone oil, soybean oil, cycloalkanes, and alkanes; and / or, the dispersant includes one or more of cellulose acetate butyrate, OP, Span, Tween, AEO, PEG, and PVA; and / or, the amount of the dispersant is 1 to 6 wt% of the mass of the organic solvent.

[0014] In one possible implementation, the preparation method of the anionic hydrogel microspheres includes: adding the aqueous phase solution to the oil phase solution under stirring conditions, dispersing it evenly, adding a catalyst, and continuing to react under stirring and heating for 4-12 hours; the resulting product is washed with an oil phase solvent and boiled with an alkaline solution, then sieved and rinsed to obtain anionic hydrogel microspheres.

[0015] In the above technical solution, an aqueous solution is added to an oil solution to form tiny aqueous droplets, which are then polymerized into spheres under conditions of heating and the addition of a catalyst.

[0016] In one possible implementation, the catalyst comprises one or more of N,N,N',N'-tetramethylethylenediamine and triethylamine; and / or, the amount of the catalyst is 10-20 wt% of the mass of the reactants; and / or, the alkaline solution comprises 0.5-2 wt% of an aqueous solution of NaHCO3 or Na2CO3.

[0017] In one possible implementation, the reaction temperature is 50-80°C; and / or the reaction time is 2-24 hours.

[0018] In one possible implementation, the preparation method of the supramolecular composite microspheres includes: preparing an aqueous solution of a cationic supramolecular compound with water; mixing the aqueous solution of the cationic supramolecular compound with the anionic hydrogel microspheres; stirring continuously for 2-5 hours; filtering; and rinsing multiple times with deionized water to obtain the supramolecular composite.

[0019] In one possible implementation, the mass concentration of the cationic supramolecular compound aqueous solution is 2-30 wt%; and / or, the volume ratio of the cationic supramolecular compound aqueous solution to the anionic hydrogel microspheres is 2:1-200:1.

[0020] In one possible implementation, the cationic supramolecular compound includes one or more of cyclodextrin, cucurbituril, calixarenes, cationic-modified derivatives of cryptanes, and analogs.

[0021] In the above technical solutions, molecules such as cyclodextrin, cucurbituril, calixarene, and cavitary ether have intramolecular hydrophobic cavities.

[0022] Secondly, embodiments of this application provide a supramolecular composite microsphere, which is prepared using the supramolecular composite microsphere preparation method provided in the first aspect.

[0023] In the above technical solution, because microspheres are prepared first and then loaded with supramolecular compounds, the composite microspheres can maintain mechanical properties close to those of the original macroporous microspheres, exhibiting excellent elasticity and channel permeability. The microspheres simultaneously possess interconnected pores, cationic supramolecular compound modification, and an anionic hydrogel matrix, giving them ample pores, surface area, and molecular cavities. Therefore, they exhibit excellent loading dose and sustained-release effects for various types of drugs, including small molecules, large molecules, cationic drugs, and non-cationic drugs.

[0024] In one possible implementation, the anionic hydrogel microspheres in the supramolecular composite microspheres have a pore diameter of 50~5000 nm.

[0025] Thirdly, embodiments of this application provide an application of the supramolecular composite microspheres provided in the first aspect, wherein the supramolecular composite microspheres are used to load drug molecules, and the drug includes one or more of macromolecular drugs, small molecule drugs, cationic drugs, and non-cationic drugs. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A schematic diagram illustrating the preparation process of supramolecular composite microspheres provided in this application embodiment; Figure 2 This is a schematic diagram of the structure of supramolecular composite microspheres according to an embodiment of this application; Figure 3 Optical images of microsphere A used in Examples 1-2; Figure 4 Optical images of the composite microspheres Am from Example 1; Figure 5 Optical images of the composite microsphere Am from Example 2; Figure 6 Optical images of microsphere a used in Comparative Examples 1-2; Figure 7 The images shown are SEM images of microspheres C from Examples 5 and 6. Detailed Implementation

[0028] Currently, drug-loadable hydrogel microspheres have been widely used in many fields due to their unique physicochemical properties and excellent biocompatibility.

[0029] In the medical field, hydrogel microspheres can serve as drug delivery carriers, enabling targeted drug release. For example, in cancer treatment, anticancer drugs can be loaded into hydrogel microspheres and delivered to the tumor site via blood vessels or injection, prolonging the drug's residence time in tumor tissue, improving efficacy, and reducing drug distribution in non-target tissues, thus reducing toxic side effects. Specifically, in transcatheter arterial chemoembolization (TACE), hydrogel microspheres achieve effective treatment of hepatocellular carcinoma through blood vessel blockage and local delivery of chemotherapy drugs. Therefore, based on the good biocompatibility, ease of transport, and anti-migration characteristics of hydrogel microspheres, they can carry anticancer drugs through blood vessels to the tumor site, blocking tumor blood vessels while simultaneously releasing the drug, achieving high-concentration local treatment.

[0030] In the fields of tissue engineering and regenerative medicine, hydrogel microspheres can serve as cell carriers for the regeneration of bone, cartilage, and soft tissue. For example, stem cell-loaded hydrogel microspheres can be transplanted to damaged sites via minimally invasive injection to promote tissue repair and regeneration. Therefore, the adjustable size, shape, and customizable internal and external structures of hydrogel microspheres enable them to fill irregular defects, providing a favorable growth environment for cells.

[0031] In the field of antibacterial applications, hydrogel microspheres possess a large specific surface area, enabling efficient storage of antibacterial drugs and effective resistance to bacterial cell aggregation. For example, encapsulating antibacterial silicon-based nickel nanoparticles within hydrogel microspheres can produce microspheres with excellent antibacterial activity, exhibiting highly efficient bactericidal capabilities against a variety of bacteria.

[0032] In the industrial field, hydrogel microspheres can serve as immobilized enzyme carriers, improving enzyme stability and reusability. For example, by immobilizing enzymes on hydrogel microspheres, they can be easily handled and recycled in industrial production while maintaining enzyme activity and catalytic efficiency. Furthermore, hydrogel microspheres can also be used to adsorb and remove pollutants, such as heavy metal ions and dyes in water, and to detect harmful substances in food.

[0033] Currently, commercially available drug-loadable hydrogel microspheres are mainly anionic microspheres. They achieve efficient loading and sustained release of small molecule cationic drugs (such as doxorubicin hydrochloride and irinotecan hydrochloride) through charge interaction and ion exchange processes, but cannot achieve efficient loading of neutral molecule drugs and macromolecule drugs.

[0034] In addition, some composite microspheres formed by introducing supramolecular host compounds such as cyclodextrin into microspheres have been reported. Although they have shown a certain broad-spectrum drug loading capacity for non-cationic drugs (such as loading silver nanoparticles, loading platinum drugs, loading stem cell liposomes, etc.), these composite microspheres usually require the introduction of supramolecular host compounds before microsphere preparation or during the microsphere formation reaction. This greatly limits the controllability and convenience of microsphere preparation.

[0035] Furthermore, if the content of supramolecular compounds introduced into these composite microspheres is too low, the broad-spectrum drug loading capacity will be limited. If the content of supramolecular compounds is increased, the rigid framework of these compounds can lead to problems with the hydrophilicity and mechanical properties of the microspheres due to improper introduction methods, thus affecting the delivery and use of the composite microspheres. Therefore, the supramolecular compound content and the mechanical properties of the microspheres cannot be balanced in these composite microspheres. For example, for composite microspheres formed by directly cross-linking cyclodextrin or its derivatives with the microsphere raw materials, sufficient cyclodextrin cavities are needed to introduce a sufficient amount of cyclodextrin. This requires increasing the degree of cross-linking of the microspheres, resulting in decreased hydrophilicity and elasticity. Moreover, the cross-linking process is accompanied by blockage of the cavity inlets, which reduces or eliminates the ability of cyclodextrin to encapsulate drugs, i.e., reduces the broad-spectrum drug loading capacity.

[0036] Therefore, a novel method for preparing composite microspheres is needed that does not affect the controllability and convenience of microsphere preparation, can increase the amount of supramolecular compounds introduced, achieve excellent broad-spectrum drug loading capacity, and at the same time retain the excellent hydrophilicity and mechanical properties of microspheres.

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0038] The following provides a detailed description of the supramolecular composite microspheres, their preparation methods, and applications according to embodiments of this application.

[0039] This application provides a method for preparing supramolecular composite microspheres, which includes the following steps: S1. Synthesis of anionic hydrogel microspheres: An aqueous solution and an oil solution are mixed to form a water-in-oil reverse suspension polymerization system. The aqueous solution includes water-soluble anionic monomers, crosslinking agents, water-soluble pore-forming agents, initiators, and water. The oil solution contains organic solvents and dispersants. The reaction yields anionic hydrogel microspheres with pores.

[0040] In some optional embodiments of this application, step S1 specifically includes the following steps: S11. Preparation of aqueous solution: Prepare an aqueous solution of water-soluble anionic monomer with water. Neutralize by slowly adding alkaline solution in an ice-water bath. Then add crosslinking agent and water-soluble pore-forming agent. After fully dissolving, a clear and transparent solution is formed. Add free radical initiator to the clear and transparent solution and mix well to obtain the aqueous solution. In some optional embodiments of this application, the water-soluble anionic monomer includes one or more of the following: carboxylic acid compounds and carboxylate compounds that simultaneously contain a carboxyl group and a double bond; sulfonic acid compounds and sulfonate compounds that simultaneously contain a sulfonate group and a double bond; exemplarily, the water-soluble anionic monomer includes: sodium acrylate. Sodium methacrylate Acrylamide, acrylic anhydride, maleic acid, maleic anhydride, itaconic acid, β-(acryloyloxy)propionic acid, 2,4-hexadienoic acid, 2,4-pentadienoic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), sodium 2-acrylamido-2-methylpropanesulfonate One or more of sodium p-styrene sulfonate.

[0041] In the embodiments of this application, unless otherwise specified, "multiple" refers to two or more.

[0042] In some alternative embodiments of this application, the crosslinking agent includes acrylamide-based crosslinking agents, such as N,N-methylenebisacrylamide. N-(2,2-dimethoxyethyl)-2-acrylamide modified polyvinyl alcohol (PN) One or more of polyethylene glycol bisacrylamide.

[0043] In some alternative embodiments of this application, the aqueous solution further includes a water-soluble nonionic monomer, typically added together with the crosslinking agent when preparing the aqueous solution; optionally, the water-soluble nonionic monomer includes vinylimidazole. N-vinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, N-isopropylacrylamide One or more of them.

[0044] In some optional embodiments of this application, the water-soluble pore-forming agent includes one or more of the following water-soluble polymers: polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), polyethylene glycol monomethyl ether, polyethylene glycol dimethyl ether, polypropylene glycol, and polyoxyethylene-polyoxypropylene copolymer.

[0045] In some optional embodiments of this application, the amount of water-soluble pore-forming agent is 10 to 50 wt% of the total mass of all functional monomers (water-soluble anionic monomers, or water-soluble anionic monomers and water-soluble nonionic monomers). For example, the amount of water-soluble pore-forming agent is 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt% of the total mass of all functional monomers, or any intermediate value between the two aforementioned values.

[0046] In some alternative embodiments of this application, the initiator includes one or more of sodium persulfate, potassium persulfate, ammonium persulfate, benzoyl peroxide (BPO), azobisisobutyronitrile (AIBN), azobisisoheptanenitrile, and azodialkylimidazoline salt.

[0047] S12. Preparation of oil phase solution: Mix organic solvent and dispersant, and heat appropriately and stir thoroughly to completely dissolve the dispersant to obtain oil phase solution.

[0048] In some alternative embodiments of this application, the organic solvent includes one or more of butyl acetate, ethyl acetate, liquid paraffin, dimethyl silicone oil, soybean oil, cycloalkanes (e.g., cyclohexane), and alkanes (e.g., n-decane, n-heptane, n-hexane).

[0049] In some alternative embodiments of this application, the dispersant includes one or more of the following: cellulose acetate butyrate, OP class (e.g., OP-4, OP-10, OP-20), Span class (e.g., Span-80, Span-60), Tween class (e.g., Tween-60, Tween-80), AEO class (e.g., AEO-7, AEO-9), PEG class (e.g., PEG-400, PEG-8000), and PVA class (e.g., PVA-1788, PVA-1799).

[0050] In some optional embodiments of this application, the amount of dispersant used is 1 to 6 wt% of the organic solvent mass. Exemplarily, the amount of dispersant used is 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt% of the organic solvent mass, or any intermediate value between the two above values.

[0051] S13. Preparation of microspheres: Under stirring conditions, an aqueous solution is added to the oil phase solution, and after uniform dispersion, a catalyst is added. The reaction is continued under stirring and heated for 4-12 hours. The obtained product is washed with an oil phase solvent and boiled with an alkaline solution, then sieved and rinsed to obtain anionic hydrogel microspheres.

[0052] In some alternative embodiments of this application, the catalyst includes one or more of N,N,N',N'-tetramethylethylenediamine (TMEDA) and triethylamine.

[0053] In some optional embodiments of this application, the amount of catalyst used is 10-20 wt% of the mass of the reactants (mainly water-soluble anionic monomers, water-soluble nonionic monomers, and crosslinking agents). For example, the amount of catalyst used is 10 wt%, 12 wt%, 15 wt%, 17 wt%, 20 wt% of the mass of the reactants, or any intermediate value between the two above values.

[0054] In some optional embodiments of this application, the alkaline solution includes 0.5~2wt% of an aqueous solution of NaHCO3 and Na2CO3.

[0055] In some optional embodiments of this application, the reaction temperature is 50~80°C; and / or the reaction time is 2~24h.

[0056] S2. Preparation of supramolecular composite microspheres: Cationic supramolecular compounds are mixed with anionic hydrogel microspheres, allowing the cationic supramolecular compounds to be loaded onto the channels and surface of the anionic hydrogel microspheres through charge interaction, thus obtaining supramolecular composite microspheres. The preparation process in step S2 is as follows: Figure 1 As shown, porous anionic hydrogel microspheres and cationic supramolecular compounds self-assemble under the influence of charge to form supramolecular composite microspheres.

[0057] In some optional embodiments of this application, the preparation method of supramolecular composite microspheres includes: preparing an aqueous solution of a cationic supramolecular compound with water, mixing the aqueous solution of the cationic supramolecular compound with anionic hydrogel microspheres, stirring continuously for 2-5 hours, filtering, and rinsing multiple times with deionized water to obtain supramolecular composite microspheres.

[0058] In some optional embodiments of this application, the mass concentration of the cationic supramolecular compound aqueous solution is 2 to 30 wt%. Exemplarily, the mass concentration of the cationic supramolecular compound aqueous solution is 2 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 30 wt%, or any intermediate value between the two above values.

[0059] In some optional embodiments of this application, the volume ratio of the cationic supramolecular compound aqueous solution to the anionic hydrogel microspheres is 2:1 to 200:1. Exemplarily, the volume ratio of the cationic supramolecular compound aqueous solution to the anionic hydrogel microspheres is 2:1, 10:1, 50:1, 100:1, 150:1, 200:1, or any intermediate value between two of the above ratios.

[0060] In some optional embodiments of this application, the cationic supramolecular compound includes one or more derivatives and analogs of molecules with intramolecular hydrophobic cavities, such as cyclodextrin, cucurbituril, calixarenes, and cryptanes, which have been cationically modified. For example, the cationic supramolecular compound includes cationic-β - One or both of cyclodextrin and cationic cucurbituril.

[0061] This application also provides a supramolecular composite microsphere, which is prepared using the supramolecular composite microsphere preparation method described in the foregoing embodiments.

[0062] The structural schematic of the supramolecular composite microspheres in this application embodiment is shown below. Figure 2 As shown, the matrix of the anionic hydrogel microspheres in the supramolecular composite microspheres is a copolymer of water-soluble anionic monomers, water-soluble nonionic monomers, and crosslinking agents. Structurally, it has large-diameter channels that connect the surface and interior of the microspheres. In some optional embodiments of this application, the pore diameter of the anionic hydrogel microspheres in the supramolecular composite microspheres is 50~5000 nm; and the inner walls of the channels and the surface of the microspheres are coated with cationic supramolecular compounds.

[0063] The supramolecular composite microspheres of this application have a large-pore structure with interconnected internal and external pores, cationic supramolecular compound modification and anionic hydrogel matrix, which makes the microspheres have sufficient pores, specific surface area, molecular cavity and anionic groups. Therefore, they have excellent drug loading and sustained release effects for various types of drugs such as small molecules, large molecules, cationic and non-cationic drugs, and are suitable for various drug delivery and application scenarios such as TACE therapy.

[0064] This application also provides an application of the supramolecular composite microspheres described in the foregoing embodiments. The supramolecular composite microspheres are used to load drug molecules, including one or more of macromolecular drugs, small molecule drugs, cationic drugs, and non-cationic drugs.

[0065] Accordingly, embodiments of this application may also provide a drug-loaded microsphere, which includes the supramolecular composite microsphere of the aforementioned embodiments and drug molecules loaded thereon, with at least a portion of the drug molecules located in the internal cavity of the cationic supramolecular compound.

[0066] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0067] Example 1 This embodiment provides a supramolecular composite microsphere, the preparation process of which is as follows: (a) Preparation of cationic supramolecular compounds: cationic-β-cyclodextrin (β-CD) n+ ), labeled m. The specific reaction formula and preparation process are as follows:

[0068] 5g βCyclodextrin was added to 10 mL of 20 wt% sodium hydroxide solution and stirred thoroughly at room temperature to dissolve. The temperature was then raised to 80 °C, and 15 mL of 30 wt% 2,3-epoxypropyltrimethylammonium chloride aqueous solution was slowly added dropwise. After the addition was complete, the temperature was maintained at 80 °C for 3 hours. After the reaction was complete, the solution was cooled to room temperature, and acetone (3 times its volume) was added, precipitating a white solid. The white solid was dissolved in a suitable amount of 5% sodium chloride aqueous solution, and then precipitated again by adding 3 times its volume of acetone. This process was repeated 3 times. After drying, a white powdery product, cationic-, was obtained. β - Cyclodextrin (yield approximately 6.4 g, 70% yield, average degree of cationic substitution 5.7), labeled m.

[0069] 1H NMR data: 1 H NMR (400MHz, D2O) delta 5.36-4.98(m,1H),4.52-4.36(m,1H),3.88(d, J =17.9Hz,4H),3.72(dd, J =11.2,5.0Hz,1H),3.69-3.60(m,1H),3.58(d, J =5.3Hz,1H),3.56-3.47(m,2H),3.35-3.16(m,7H).

[0070] (ii) Preparation of anionic hydrogel microspheres: Sodium polyacrylate microspheres, labeled as microsphere A.

[0071] Weigh 1.46 g of methylenebisacrylamide (MBA) (crosslinking agent) and dissolve it in 16 mL of 50% ethanol aqueous solution under sonication, forming a clear solution, which is designated as aqueous phase 1. Then weigh 6.8 g of acrylic acid (AA) (water-soluble anionic monomer) and neutralize it with 13 mL of 20% NaOH solution under ice-water bath conditions; this solution is designated as aqueous phase 2. Mix aqueous phase 1 and aqueous phase 2 thoroughly, and add 2.25 g of PEG400 (water-soluble pore-forming agent). After thoroughly mixing to form a clear and transparent solution, add 2.4 mL of 0.1 g / mL ammonium persulfate (APS) solution (initiator) to the solution. The mixed solution was then added to a flask containing 4.5 g of cellulose acetate butyrate dissolved in 150 mL of butyl acetate. After uniform dispersion at 45 °C for 30 min, the system was heated to 55 °C, and then 3.2 mL of 50% TMEDA / butyl acetate solution was added to the system. The reaction was carried out for 4 h. The resulting product was washed with butyl acetate and deionized water, and then boiled in 0.5 wt% NaHCO3 aqueous solution for 30 min. Finally, it was sieved to obtain porous sodium polyacrylate microspheres, labeled as microsphere A.

[0072] (III) Preparation of supramolecular composite microspheres: sodium polyacrylate - β - Cyclodextrin composite microspheres, labeled as composite microspheres Am. The specific preparation process is as follows: Add 10 mL of sodium polyacrylate microspheres (A) to a three-necked flask, then add 100 mL of 2 wt% cationic polyacrylate microspheres. β An aqueous solution of sodium polyacrylate-β-cyclodextrin (m) was prepared and stirred mechanically at 100 rpm for 3 hours. After the reaction was complete, the mixture was filtered through a sieve and the microspheres were washed three times with purified water to obtain sodium polyacrylate-β-cyclodextrin composite microspheres, labeled as composite microspheres Am.

[0073] Example 2 This embodiment provides a supramolecular composite microsphere, the preparation process of which is as follows: (a) Preparation of cationic supramolecular compounds: cationic cucurbituril (CB) n+ The specific preparation process is as follows: (1) Preparation of cucurbituril (CB): The specific reaction formula and preparation process are as follows:

[0074] 210g of paraformaldehyde powder and 500g of glyceryl urea powder were added in one batch to 700mL of concentrated hydrochloric acid under vigorous stirring and ice water cooling. Vigorous stirring was continued for 30 minutes to ensure complete dissolution. The mixture was then heated to 100℃ and reacted for 10 hours. After the reaction was complete, the mixture was cooled to room temperature and filtered. The filtrate was concentrated to one-quarter of its volume, and 400mL of pure water was added, resulting in the precipitation of a white solid. This filtrate was filtered and collected. Under vigorous stirring, the filtrate was poured into four times its volume of methanol, resulting in the precipitation of a nearly white precipitate. After settling at room temperature for 24 hours, the precipitate was filtered. The precipitate was recrystallized multiple times using a glycerol aqueous solution-methanol system, and after drying, a white powder product, cucurbituril, was obtained (yield approximately 140g, about 20%).

[0075] 1H NMR data: 1 ¹H NMR (400 MHz, D₂O) δ 5.64 (d, J = 15.4 Hz, 14H), 5.45 (s, 14H), 3.96 (d, J = 15.4 Hz, 14H); Mass spectrometry data: MADIL (TOF): m / z 1162 (M⁺), 1163 (M⁺) + ).

[0076] (2) Preparation of hydroxycucurbita (CB(OH)n), the specific reaction formula and preparation process are as follows:

[0077] 10 g (8.6 mmol) of cucurbituril, 14 g (52 mmol) of potassium persulfate, 8.9 g (52 mmol) of potassium sulfate, and 700 mL of purified water were added to a reaction flask at once. The mixture was stirred thoroughly for 10 min, and after purging with nitrogen, the reaction was carried out at 85 °C under nitrogen protection for 12 h. After the reaction was completed, the insoluble matter was removed by filtration, and the filtrate was evaporated to dryness under reduced pressure. The residual solid was extracted with dimethyl sulfoxide, and the extract was dried under vacuum to obtain hydroxycucurbituril, which is a cucurbituril derivative with 4-7 different hydroxyl substitutions (yield approximately 8.2 g, yield approximately 50%, average degree of hydroxyl substitution 6).

[0078] 1H NMR data: 1 ¹H NMR (400MHz, DMSO-d6) δ 7.93 (br, 6H), 5.71 (m, 4H), 5.46 (m, 14H), 5.16 (m, 4H), 4.31–4.52 (m, 14H); Mass spectrometry data: MALDI (TOF): m / z (M=CB(OH)n(H)14-n)[M+Na]+): 1249.1 (n=4), 1265.1 (n=5), 1281.1 (n=6), 1297.1 (n=7).

[0079] (3) Preparation of cationic cucurbituril (CB) n+ The specific reaction formula and preparation process are as follows:

[0080] 4.8 g of the prepared hydroxycucurbita was added to 10 mL of a 20 wt% sodium hydroxide solution and stirred thoroughly at room temperature to dissolve. The temperature was then raised to 80 °C, and 15 mL of a 30 wt% 2,3-epoxypropyltrimethylammonium chloride aqueous solution was slowly added dropwise. After the addition was complete, the reaction was continued at 80 °C for 3 h. After the reaction was complete, the solution was cooled to room temperature, and acetone (3 times its volume) was added, precipitating a white solid. The white solid was dissolved in a suitable amount of 5% sodium chloride aqueous solution, and then 3 times its volume of acetone was added again to precipitate, repeating this process 3 times. After drying, the precipitated solid yielded a white powdery product, cationic cucurbita (yield approximately 0.6 g, yield approximately 83%, average degree of cationic substitution 3.9), labeled as n.

[0081] 1H NMR data: 1 H NMR(400MHz,DMSO-d6)δ7.93(br,2H),7.31(br,4H),5.68(m,4H),5.51(m,14H),5.23( m,4H),4.32–4.52(m,14H),3.60-3.58(m,12H),3.56-3.45(m,8H),3.25-3,17(s,35H).

[0082] (ii) Anionic hydrogel microspheres were prepared according to the preparation method in Example 1: sodium polyacrylate microspheres, labeled as microsphere A.

[0083] (III) Preparation of supramolecular composite microspheres: Sodium polyacrylate-cucurbita composite microspheres, labeled as composite microsphere An.

[0084] 10 mL of sodium polyacrylate microspheres (A) was added to a three-necked flask, followed by 100 mL of a 2 wt% aqueous solution of cationic cucurbituril (n). The mixture was stirred mechanically at 100 rpm for 3 hours. After the reaction was complete, the mixture was filtered through a sieve and the microspheres were washed three times with purified water to obtain sodium polyacrylate-cucurbituril composite microspheres, namely An.

[0085] Example 3 This embodiment provides a supramolecular composite microsphere, the preparation process of which is as follows: (a) Preparation of cationic supramolecular compounds according to the preparation method in Example 1: cationic-β-cyclodextrin (β-CD) n+ ), marked as m.

[0086] (II) Preparation of anionic hydrogel microspheres: Polyvinyl alcohol microspheres, labeled as microsphere B. The specific preparation process is as follows: (1) Synthesis of NAAADA-modified macromolecular polyvinyl alcohol monomer (PN) solution: 100 mL of purified water was added to a 250 mL three-necked flask equipped with a top-mounted mechanical stirrer, and about 15 g of PVA (model 1788) (water-soluble nonionic monomer) was added. The mixture was heated to 95 °C to dissolve and then cooled to room temperature. 1.65 g of N-(2,2-dimethoxyethyl)-2-acrylamide (NAAADA) (crosslinking agent) was added, followed by 10 mL of concentrated hydrochloric acid. The reaction was carried out at room temperature for 14 hours, and then neutralized to pH=7 with 2.5 M sodium hydroxide solution to obtain macromolecular polyvinyl alcohol monomer solution.

[0087] (2) Synthesis of polyvinyl alcohol microspheres by reverse suspension polymerization: 600 mL of butyl acetate was added to a 1 L three-necked flask equipped with a top-mounted mechanical stirrer, and 18 g of cellulose acetate butyrate was added to dissolve it, yielding an oil phase; 8.61 g of sodium acrylamide-2-methylpropanesulfonate (AMPS sodium) (water-soluble anionic monomer) was dissolved in 60 mL of water, and 160 g of macromolecular polyvinyl alcohol monomer solution and 150 g of polyethylene glycol dimethyl ether (average molecular weight 2000) (water-soluble pore-forming agent) were added, followed by 1.5 g of potassium persulfate (initiator), yielding an aqueous phase. The rotation speed was set to 400 rpm, and the aqueous phase was added dropwise to the oil phase; after the addition was complete, the temperature was raised to 55 °C, and 2.2 mL of tetramethylethylenediamine was added, and the reaction was allowed to proceed for 8 h. After washing with 5% sodium bicarbonate solution and purified water, polyvinyl alcohol microspheres were obtained and labeled as microsphere B.

[0088] (III) Preparation of supramolecular composite microspheres: polyvinyl alcohol - β - Cyclodextrin composite microspheres, labeled as composite microspheres Bm. The specific preparation process is as follows: 10 mL of polyvinyl alcohol microspheres (B) were added to a three-necked flask, followed by 100 mL of an aqueous solution of 2 wt% cationic β-cyclodextrin (m). The mixture was stirred mechanically at 100 rpm for 3 hours. After the reaction was complete, the mixture was filtered through a sieve and the microspheres were washed three times with purified water to obtain polyvinyl alcohol-β-cyclodextrin composite microspheres, labeled as composite microspheres Bm.

[0089] Example 4 This embodiment provides a supramolecular composite microsphere, the preparation process of which is as follows: (a) Preparation of cationic supramolecular compounds according to the preparation method in Example 2: cationic cucurbituril (CB n+ ), labeled as n.

[0090] (ii) Anionic hydrogel microspheres were prepared according to the preparation method in Example 3: polyvinyl alcohol microspheres, labeled as microsphere B.

[0091] (III) Preparation of supramolecular composite microspheres: Polyvinyl alcohol-cucurbita composite microspheres, labeled as composite microspheres Bn. The specific preparation process is as follows: 10 mL of polyvinyl alcohol microspheres (B) were added to a three-necked flask, followed by 100 mL of an aqueous solution of 2 wt% cationic cucurbituril (n). The mixture was stirred mechanically at 100 rpm for 3 hours. After the reaction was complete, the mixture was filtered through a sieve and the microspheres were washed three times with purified water to obtain polyvinyl alcohol-cucurbituril composite microspheres, labeled as composite microspheres Bn.

[0092] Example 5 This embodiment provides a supramolecular composite microsphere, the preparation process of which is as follows: (a) Preparation of cationic supramolecular compounds according to the preparation method in Example 1: cationic-β-cyclodextrin (β-CD) n+ ), marked as m.

[0093] (II) Preparation of anionic hydrogel microspheres: Polyvinyl imidazole microspheres, labeled as microsphere C. The specific preparation process is as follows: Weigh 2.92 g of methylenebisacrylamide (MBA) (crosslinking agent) and dissolve it in 32 mL of 50% ethanol aqueous solution under ultrasonication to form a clear solution. Then add 8.9 g of vinylimidazole (water-soluble nonionic monomer) and mix thoroughly. This solution is designated as aqueous phase 1. Next, weigh 19.5 g of AMPS (water-soluble anionic monomer) and neutralize it with 13 mL of 20% NaOH solution under ice-water bath conditions. This solution is designated as aqueous phase 2. After neutralization, mix aqueous phase 1 and aqueous phase 2 thoroughly and add 4.7 g of PVP58000 (water-soluble pore-forming agent). After mixing thoroughly to form a clear and transparent solution, add 2.4 mL of 0.1 g / mL APS solution (initiator) to the solution. The mixed solution was then added to a flask containing 4.5 g of cellulose acetate butyrate dissolved in 150 mL of butyl acetate. After uniform dispersion at 45 °C for 30 min, the system was heated to 55 °C, and then 3.2 mL of 50% TMEDA / butyl acetate solution was added to the system. The reaction was carried out for 4 h. The resulting product was washed with butyl acetate and deionized water, and then boiled in 0.5 wt% NaHCO3 aqueous solution for 30 min. Finally, it was sieved to obtain polyvinyl imidazole microspheres, labeled as microsphere C.

[0094] (III) Preparation of supramolecular composite microspheres: polyvinylimidazole- β - Cyclodextrin composite microspheres, labeled Cm. The specific preparation process is as follows: Add 10 mL of polyvinyl imidazole microspheres (C) to a three-necked flask, then add 100 mL of 2 wt% cationic- β An aqueous solution of cyclodextrin (m) was stirred mechanically at 100 rpm for 3 hours. After the reaction was complete, the mixture was filtered through a sieve, and the microspheres were washed three times with purified water to obtain polyvinylimidazole- β - Cyclodextrin complex microspheres, labeled as complex microspheres Cm.

[0095] Example 6 This embodiment provides a supramolecular composite microsphere, the preparation process of which is as follows: (a) Preparation of cationic supramolecular compounds according to the preparation method in Example 2: cationic cucurbituril (CB n+ ), labeled as n.

[0096] (ii) Anionic hydrogel microspheres were prepared according to the preparation method in Example 5: polyvinyl imidazole microspheres, labeled as microsphere C.

[0097] (III) Preparation of supramolecular composite microspheres: Polyvinyl imidazole-cucurbituril composite microspheres, labeled as composite microspheres Cn. The specific preparation process is as follows: 10 mL of polyvinylimidazole (C) was added to a three-necked flask, followed by 100 mL of a 2 wt% aqueous solution of cationic cucurbituril (n). The mixture was stirred mechanically at 100 rpm for 3 hours. After the reaction was complete, the mixture was filtered through a sieve and the microspheres were washed three times with purified water to obtain polyvinylimidazole-cucurbituril composite microspheres, labeled as composite microspheres Cn.

[0098] Example 7 This embodiment provides a supramolecular composite microsphere, the preparation process of which is as follows: (a) Preparation of cationic supramolecular compounds according to the preparation method in Example 1: cationic-β-cyclodextrin (β-CD) n+ ), marked as m.

[0099] (II) Preparation of anionic hydrogel microspheres: Synthesis of polyethylene glycol microspheres, labeled as microsphere D. The specific preparation process is as follows: (1) Preparation of aqueous phase: Accurately weigh 3.2 g of diethylene glycol diglycidyl ether (water-soluble nonionic monomer) into a glass bottle, add 6 mL of 12% NaOH aqueous solution, and stir at room temperature for 0.5 h on a magnetic stirrer. Add 9.5 mL of 50% N-hydroxyethyl acrylamide aqueous solution (crosslinking agent) to the bottle and continue stirring for 2 h. Neutralize the system solution with concentrated hydrochloric acid to neutral, add an aqueous solution containing 6.5 g of sodium acrylate (water-soluble anionic monomer), then add 4.5 g of polyvinyl alcohol solution (PVA1799, 10 wt%) (water-soluble pore-forming agent), stir for 0.5 h, add 180 mg of ammonium persulfate (initiator), stir evenly for 0.5 h to prepare an aqueous phase solution.

[0100] (2) Preparation of oil phase: Add 3g of cellulose acetate butyrate to 100mL of butyl acetate and stir at 50℃ to dissolve and form a homogeneous oil phase solution.

[0101] (3) Reverse suspension polymerization: Under stirring conditions of 50°C and 300 rpm, the aqueous phase solution prepared above was slowly added to the oil phase solution to form a water-in-oil reverse suspension polymerization system. The reaction was maintained at 50°C for 30 minutes, and then 1.2 mL of tetramethylethylenediamine (TMEDA) was added to the oil phase solution, and the temperature was raised to 80°C for 4 hours.

[0102] (4) Purification: After the reaction is completed, the obtained microspheres are washed repeatedly with butyl acetate, purified water and 5% sodium bicarbonate aqueous solution 3-5 times to obtain polyethylene glycol microspheres, which are labeled as microspheres D.

[0103] (III) Preparation of supramolecular composite microspheres: polyethylene glycol- β - Cyclodextrin composite microspheres, labeled as composite microspheres Dm. The specific preparation process is as follows: Add 10 mL of polyethylene glycol microspheres (D) to a three-necked flask, then add 100 mL of 2 wt% cationic polymeric acid. β An aqueous solution of cyclodextrin (m) was mechanically stirred at 100 rpm for 3 hours. After the reaction was complete, the mixture was filtered through a sieve, and the microspheres were washed three times with purified water to obtain polyethylene glycol. β - Cyclodextrin complex microspheres, labeled as complex microspheres Dm.

[0104] Example 8 This embodiment provides a supramolecular composite microsphere, the preparation process of which is as follows: (a) Preparation of cationic supramolecular compounds according to the preparation method in Example 2: cationic cucurbituril (CB n+ ), labeled as n.

[0105] (ii) Anionic hydrogel microspheres were prepared according to the preparation method in Example 7: polyethylene glycol microspheres, labeled as microsphere D.

[0106] (III) Preparation of supramolecular composite microspheres: Polyethylene glycol-cucurbita composite microspheres, labeled as composite microspheres Dn. The specific preparation process is as follows: 10 mL of polyethylene glycol microspheres (D) were added to a three-necked flask, followed by 100 mL of an aqueous solution of 2 wt% cationic cucurbituril (n). The mixture was stirred mechanically at 100 rpm for 3 hours. After the reaction was complete, the mixture was filtered through a sieve and the microspheres were washed three times with purified water to obtain polyethylene glycol-cucurbituril composite microspheres, labeled as composite microspheres Dn.

[0107] Example 9 This embodiment provides a supramolecular composite microsphere, the preparation process of which is as follows: (a) Preparation of cationic supramolecular compounds according to the preparation method in Example 1: cationic-β-cyclodextrin (β-CD) n+ ), marked as m.

[0108] (II) Preparation of anionic hydrogel microspheres: Poly(N-isopropyl)acrylamide microspheres, labeled as microsphere E. The specific preparation process is as follows: Weigh 1.46 g of methylenebisacrylamide (MBA) (crosslinking agent) and dissolve it in 16 mL of 50% ethanol aqueous solution under sonication, forming a clear solution, which is designated as aqueous phase 1. Then weigh 7.2 g of AMPS (water-soluble anionic monomer) and neutralize it with 12 mL of 20% NaOH solution in an ice-water bath; this solution is designated as aqueous phase 2. After neutralization, mix aqueous phase 1 and aqueous phase 2 thoroughly, and then add 5.4 g of [amount missing] ... NIsopropylacrylamide (a water-soluble nonionic monomer) and 3.8 g of polyoxyethylene-polyoxypropylene copolymer (Mn approximately 2500) (a water-soluble pore-forming agent) were thoroughly mixed to form a clear and transparent solution. Then, 2.4 mL of 0.1 g / mL ammonium persulfate (APS) solution (an initiator) was added to the solution. The mixed solution was then added to a flask containing 4.5 g of cellulose acetate butyrate dissolved in 150 mL of butyl acetate. After uniform dispersion at 45 °C for 30 min, the system was heated to 55 °C, and 3.2 mL of 50% TMEDA / butyl acetate solution was added. The reaction was carried out for 4 h. The resulting product was washed with butyl acetate and deionized water, then boiled in 0.5 wt% NaHCO3 aqueous solution for 30 min. Finally, it was sieved to obtain poly(N-isopropyl)acrylamide microspheres, labeled as microsphere E.

[0109] (III) Preparation of supramolecular composite microspheres: poly(N-isopropyl)acrylamide- β - Cyclodextrin microspheres, labeled as composite microspheres Em. The specific preparation process is as follows: 10 mL of poly(N-isopropyl)acrylamide microspheres (E) were added to a three-necked flask, followed by 100 mL of a 2 wt% aqueous solution of cationic β-cyclodextrin (m). The mixture was mechanically stirred at 100 rpm for 3 hours. After the reaction was complete, the mixture was filtered through a sieve, and the microspheres were washed three times with purified water to obtain poly(N-isopropyl)acrylamide. β - Cyclodextrin complex microspheres, labeled as complex microspheres Em.

[0110] Example 10 This embodiment provides a supramolecular composite microsphere, the preparation process of which is as follows: (a) Preparation of cationic supramolecular compounds according to the preparation method in Example 2: cationic cucurbituril (CB n+ ), labeled as n.

[0111] (ii) Anionic hydrogel microspheres were prepared according to the preparation method in Example 9: poly(N-isopropyl)acrylamide microspheres, labeled as microsphere E.

[0112] (III) Preparation of supramolecular composite microspheres: Poly(N-isopropyl)acrylamide-cucurbitaurea microspheres, labeled as composite microspheres En. The specific preparation process is as follows: 10 mL of poly(N-isopropyl)acrylamide microspheres (E) were added to a three-necked flask, followed by 100 mL of a 2 wt% aqueous solution of cationic cucurbituril (n). The mixture was stirred mechanically at 100 rpm for 3 hours. After the reaction was complete, the mixture was filtered through a sieve and the microspheres were washed three times with purified water to obtain poly(N-isopropyl)acrylamide-cucurbituril composite microspheres, labeled as composite microspheres En.

[0113] Comparative Example 1 This comparative example provides a supramolecular composite microsphere, the preparation process of which differs from that of Example 1 in that PEG400 is not added during the preparation of polyacrylic acid microspheres, resulting in polyacrylic acid microspheres without pores, which are labeled as microsphere a.

[0114] Using the polyacrylic acid microspheres (a), supramolecular composite microspheres were prepared according to the same method: sodium polyacrylate- β - Cyclodextrin complex microspheres, labeled as complex microspheres am.

[0115] Comparative Example 2 This comparative example provides a supramolecular composite microsphere, the preparation process of which differs from that of Example 2 in that PEG400 is not added during the preparation of polyacrylic acid microspheres, resulting in polyacrylic acid microspheres without pores, which are labeled as microsphere a.

[0116] Using the polyacrylic acid microspheres (a), supramolecular composite microspheres were prepared by the same method: sodium polyacrylate-cucurbituril composite microspheres, labeled as composite microsphere an.

[0117] Comparative Example 3 This comparative example provides a supramolecular composite microsphere, the preparation process of which differs from that of Example 3 in that: in the process of preparing polyvinyl alcohol microspheres, polyethylene glycol dimethyl ether is not added, resulting in polyvinyl alcohol microspheres without channels, which are labeled as microsphere b.

[0118] Using the polyvinyl alcohol microspheres (b), supramolecular composite microspheres were prepared according to the same method: polyvinyl alcohol- β - Cyclodextrin complex microspheres, labeled as complex microspheres bm.

[0119] Comparative Example 4 This comparative example provides a supramolecular composite microsphere, the preparation process of which differs from that of Example 4 in that: in the process of preparing polyvinyl alcohol microspheres, polyethylene glycol dimethyl ether is not added, resulting in polyvinyl alcohol microspheres without channels, labeled as microsphere b.

[0120] Using the same method, supramolecular composite microspheres were prepared from the polyvinyl alcohol microspheres (b): polyvinyl alcohol-cucurbita composite microspheres, labeled as composite microspheres bn.

[0121] Comparative Example 5 This comparative example provides a supramolecular composite microsphere, the preparation process of which differs from that of Example 5 in that: PVP58000 is not added during the preparation of polyvinyl imidazole microspheres, resulting in polyvinyl imidazole microspheres without pores, labeled as microsphere c.

[0122] Using the polyvinylimidazole microspheres (c), supramolecular composite microspheres were prepared according to the same method: polyvinylimidazole- β- Cyclodextrin complex microspheres, labeled as complex microspheres cm.

[0123] Comparative Example 6 This comparative example provides a supramolecular composite microsphere, the preparation process of which differs from that of Example 6 in that: PVP58000 is not added during the preparation of polyvinyl imidazole microspheres, resulting in polyvinyl imidazole microspheres without pores, labeled as microsphere c.

[0124] Using the same method, supramolecular composite microspheres were prepared from the polyvinyl imidazole microspheres (c): polyvinyl imidazole-cucurbituril composite microspheres, labeled as composite microspheres cn.

[0125] Comparative Example 7 This comparative example provides a supramolecular composite microsphere, the preparation process of which differs from that of Example 7 in that PVA is not added during the preparation of polyethylene glycol microspheres, resulting in polyethylene glycol microspheres without pores, which are labeled as microspheres d.

[0126] Using the same method, supramolecular composite microspheres were prepared from the polyethylene glycol microspheres (d): polyethylene glycol- β - Cyclodextrin complex microspheres, labeled as complex microspheres dm.

[0127] Comparative Example 8 This comparative example provides a supramolecular composite microsphere, the preparation process of which differs from that of Example 8 in that PVA is not added during the preparation of polyethylene glycol microspheres, resulting in polyethylene glycol microspheres without pores, which are labeled as microspheres d.

[0128] Using the same method, supramolecular composite microspheres were prepared from the polyethylene glycol microspheres (d): polyethylene glycol-cucurbita composite microspheres, labeled as composite microspheres dn.

[0129] Comparative Example 9 This comparative example provides a supramolecular composite microsphere, the preparation process of which differs from that of Example 9 in that: in the process of preparing poly(N-isopropyl)acrylamide microspheres, polyoxyethylene-polyoxypropylene copolymer is not added, resulting in poly(N-isopropyl)acrylamide microspheres without pores, which are labeled as microsphere e.

[0130] Using the poly(N-isopropyl)acrylamide microspheres (e), supramolecular composite microspheres were prepared by the same method: poly(N-isopropyl)acrylamide- β - Cyclodextrin complex microspheres, labeled as complex microspheres em.

[0131] Comparative Example 10 This comparative example provides a supramolecular composite microsphere, the preparation process of which differs from that of Example 10 in that: in the process of preparing poly(N-isopropyl)acrylamide microspheres, polyoxyethylene-polyoxypropylene copolymer is not added, resulting in poly(N-isopropyl)acrylamide microspheres without pores, which are labeled as microsphere e.

[0132] Using the poly(N-isopropyl)acrylamide microspheres (e), supramolecular composite microspheres were prepared by the same method: poly(N-isopropyl)acrylamide-cucurbituril composite microspheres, labeled as composite microspheres en.

[0133] I. Visual Inspection Microspheres A-E prepared using water-soluble pore-forming agents in Examples 1-10 and microspheres a-e prepared without pore-forming agents in Comparative Examples 1-10 show obvious differences in appearance. Microsphere A is a milky white with weak light transmission. Figures 3~5 Due to their low light transmittance, microspheres A, Am, and An appear darker under an optical microscope; while microsphere a, made of the same material, is translucent. Figure 6 Microsphere a appears brightly colored under an optical microscope. According to... Figure 7 Microsphere C shows a clear pore structure under a scanning electron microscope (SEM).

[0134] II. Characterization of Drug Delivery Performance Gemcitabine hydrochloride loading test: 1 mL of each of the microspheres A-E used in Examples 1-10, and their respective prepared composite microspheres Am, An, Bm, Bn, Cm, Cn, Dm, Dn, Em, En; and the microspheres a-e used in Comparative Examples 1-10, and their respective prepared composite microspheres am, an, bm, bn, cm, cn, dm, dn, em, en were taken and numbered. The surface moisture of the microspheres was removed with filter paper, and the microspheres were transferred to vials. 10 mL of gemcitabine hydrochloride aqueous solution (20 mg / mL) was added to each vial, and the mixture was shaken. The solution concentration was tested using high-performance liquid chromatography (HPLC) within 45 min, and the drug loading of the embolization microspheres was calculated. The results are shown in Table 1 below. Table 1. Drug loading of gemcitabine hydrochloride on different microspheres

[0135] Oxaliplatin drug loading test: 1 mL of each of the microspheres A-E used in Examples 1-10, and their respective prepared composite microspheres Am, An, Bm, Bn, Cm, Cn, Dm, Dn, Em, En; and microspheres a-e used in Microspheres a-10, and their respective prepared composite microspheres am, an, bm, bn, cm, cn, dm, dn, em, en were taken and numbered. The surface moisture of the microspheres was removed with filter paper, and the microspheres were transferred to vials. 10 mL of oxaliplatin aqueous solution (5 mg / mL) was added to each vial, and the mixture was shaken. The solution concentration was tested using high-performance liquid chromatography (HPLC) within 45 min, and the drug loading of the embolization microspheres was calculated. The results are shown in Table 2 below. Table 2. Drug loading of oxaliplatin on different microspheres

[0136] Sodium salicylate loading test: 1 mL of each of the microspheres A-E used in Examples 1-10, and their respective prepared composite microspheres Am, An, Bm, Bn, Cm, Cn, Dm, Dn, Em, En; and microspheres a-e used in Microspheres a-10, and their respective prepared composite microspheres am, an, bm, bn, cm, cn, dm, dn, em, en were taken and numbered. The surface moisture of the microspheres was removed with filter paper, and the microspheres were transferred to vials. 10 mL of sodium salicylate aqueous solution (10 mg / mL) was added to each vial, and the mixture was shaken. The solution concentration was tested using high performance liquid chromatography within 45 min, and the drug loading of the embolization microspheres was calculated. The results are shown in Table 3 below. Table 3. Drug loading of sodium salicylate on different microspheres

[0137] Albumin-bound paclitaxel loading test: 1 mL of each of the microspheres A-E used in Examples 1-10, and their respective prepared composite microspheres Am, An, Bm, Bn, Cm, Cn, Dm, Dn, Em, En; and microspheres a-e used in Microspheres a-10, and their respective prepared composite microspheres am, an, bm, bn, cm, cn, dm, dn, em, en were taken and numbered. The surface moisture of the microspheres was removed with filter paper, and the microspheres were transferred to vials. 2 mL of albumin-bound paclitaxel solution (20 mg paclitaxel / mL) was added to each vial, and the mixture was shaken. The solution concentration was tested using high-performance liquid chromatography (HPLC) within 45 min, and the drug loading of the embolization microspheres was calculated. The results are shown in Table 4 below. Table 4. Drug loading of albumin-bound paclitaxel on different microspheres

[0138] Analysis of drug loading test results: Based on the drug loading data of the microspheres in the above examples and the comparative microspheres, it can be seen that the drug loading of microspheres A to E after pore formation is improved to a certain extent compared with the non-pore-formed microspheres a to e. This may be because the microspheres after pore formation have a pore structure that connects the inside and outside, which is more conducive to the penetration of drug molecules into the interior of the microspheres.

[0139] The composite microspheres Am~En, prepared by further compounding microspheres A~E with cationic supramolecular compounds (m, n), showed a further improvement in drug loading compared to the composite microspheres am~en prepared by further compounding non-porous microspheres a~e with cationic supramolecular compounds (m, n). Especially for small molecule drugs, the compounded supramolecular compounds provided additional drug-loading cavities, significantly increasing drug loading. However, for large molecule drugs, such as albumin-bound paclitaxel, the drug loading increased only slightly after supramolecular compounding, possibly because albumin's molecular weight is too large to form an additional loading effect with the supramolecular cavity.

[0140] Comparative studies of non-porous microspheres a-e and their corresponding composite microspheres am-en showed no significant difference in drug loading. This may be because these microspheres lack large pore structures, making them unable to effectively adsorb and recombine supramolecular compounds; instead, only a small amount is adsorbed on the microsphere surface, thus failing to improve the drug loading performance of the microspheres.

[0141] Drug release performance test: Microspheres loaded with the four drugs were placed in beakers, and 100 mL of physiological saline was added. The solution concentration was tested by high performance liquid chromatography within 60 min, and the drug release rate of the microspheres was calculated. The results are shown in Tables 5-8 below: Table 5. Release rates of gemcitabine hydrochloride from different microspheres

[0142] Table 6. Oxaliplatin release rates from different microspheres

[0143] Table 7. Release rates of sodium salicylate from different microspheres

[0144] Table 8. Release rates of albumin-bound paclitaxel from different microspheres

[0145] Analysis of drug release test results: Data from Tables 5-8 show that there was no significant difference in the release rate of small molecule drugs between porous microspheres (microsphere A) and non-porous microspheres (microsphere a), with both releasing completely within 15 minutes. The sustained-release effect of small molecule drugs was significantly enhanced after microspheres were combined with supramolecular compounds (composite microspheres Am and An, compared to composite microspheres am and an). For the macromolecular drug albumin-paclitaxel, a certain degree of sustained-release effect was observed due to the strong van der Waals forces between the microspheres and the macroporous microspheres. Furthermore, there was no significant difference in drug release regardless of whether microsphere a was combined with a supramolecular compound.

[0146] III. Characterization of the physical properties of microspheres Microspheres A, a, Am, and An were finely sieved to obtain microspheres with a particle size of 100-200 μm. Their elasticity and strength were then tested (the method was as follows: microspheres were laid flat on a glass slide, placed under the probe of a texture analyzer (TAXT plus C), and the Hold Compression mode was selected for testing). The data are shown in Table 9 below. Table 9 Mechanical properties of different microspheres

[0147] In addition, the microspheres A to E used in Examples 1 to 10 above, as well as the composite microspheres Am, An, Bm, Bn, Cm, Cn, Dm, Dn, Em, and En prepared by each of them; and the microspheres a to e used in Comparative Examples 1 to 10, as well as the composite microspheres am, an, bm, bn, cm, cn, dm, dn, em, and en prepared by each of them, can all pass smoothly through the 2.6F microcatheter, meeting the requirements for the use of embolization microspheres.

[0148] In summary, the supramolecular composite microspheres, their preparation method, and applications described in this application demonstrate that the microsphere preparation process is controllable and convenient. The resulting composite microspheres possess excellent broad-spectrum drug loading capacity, exhibiting superior loading and sustained-release effects for various macromolecules, small molecules, cationic and non-cationic drugs. They also possess excellent hydrophilicity and mechanical properties, making them suitable for various application scenarios such as TACE therapy.

[0149] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for preparing supramolecular composite microspheres, characterized in that, It includes the following steps: An aqueous solution and an oil solution are mixed to form a water-in-oil reverse suspension polymerization system. The aqueous solution includes a water-soluble anionic monomer, a crosslinking agent, a water-soluble pore-forming agent, an initiator, and water. The oil solution contains an organic solvent and a dispersant. The reaction yields anionic hydrogel microspheres with pores. A cationic supramolecular compound is mixed with the anionic hydrogel microspheres, so that the cationic supramolecular compound is loaded onto the pores and surface of the anionic hydrogel microspheres through charge interaction, thereby obtaining supramolecular composite microspheres.

2. The method for preparing supramolecular composite microspheres according to claim 1, characterized in that, The method for preparing the aqueous solution includes: preparing an aqueous solution of a water-soluble anionic monomer and water, neutralizing it by slowly adding an alkaline solution dropwise under an ice-water bath, then adding the crosslinking agent and the water-soluble pore-forming agent, dissolving them completely, adding the initiator, mixing them evenly, and obtaining the aqueous solution. The method for preparing the oil phase solution includes: mixing an organic solvent and a dispersant, stirring thoroughly to completely dissolve the dispersant, and obtaining the oil phase solution.

3. The method for preparing supramolecular composite microspheres according to claim 1 or 2, characterized in that, The water-soluble anionic monomers include one or more of the following: carboxylic acid compounds and carboxylate compounds that simultaneously contain carboxylate groups and double bonds, sulfonic acid compounds and sulfonate compounds that simultaneously contain sulfonate groups and double bonds. And / or, the crosslinking agent includes one or more of N,N-methylenebisacrylamide, N-(2,2-dimethoxyethyl)-2-acrylamide-modified polyvinyl alcohol, and polyethylene glycol bisacrylamide.

4. The method for preparing supramolecular composite microspheres according to claim 1 or 2, characterized in that, The aqueous solution further includes a water-soluble nonionic monomer; optionally, the water-soluble nonionic monomer includes one or more of vinylimidazole, N-vinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, and N-isopropylacrylamide.

5. The method for preparing supramolecular composite microspheres according to claim 1 or 2, characterized in that, The water-soluble pore-forming agent includes one or more of polyethylene glycol, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol monomethyl ether, polyethylene glycol dimethyl ether, polypropylene glycol, and polyoxyethylene-polyoxypropylene copolymer. And / or, the amount of the water-soluble pore-forming agent is 10-50 wt% of the total mass of all functional monomers; And / or, the initiator includes one or more of sodium persulfate, potassium persulfate, ammonium persulfate, benzoyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, and azodialkylimidazoline salt.

6. The method for preparing supramolecular composite microspheres according to claim 1 or 2, characterized in that, The organic solvent includes one or more of butyl acetate, ethyl acetate, liquid paraffin, dimethyl silicone oil, soybean oil, cycloalkanes, and alkanes; And / or, the dispersant includes one or more of cellulose acetate butyrate, OP type, Span type, Tween type, AEO type, PEG type and PVA type; And / or, the amount of the dispersant is 1 to 6 wt% of the mass of the organic solvent.

7. The method for preparing supramolecular composite microspheres according to claim 1, characterized in that, The preparation method of the anionic hydrogel microspheres includes: adding the aqueous phase solution to the oil phase solution under stirring conditions, dispersing it evenly, adding a catalyst, and continuing to stir and heating the reaction for 4-12 hours; the resulting product is washed with an oil phase solvent and boiled with an alkaline solution, then sieved and rinsed to obtain anionic hydrogel microspheres.

8. The method for preparing supramolecular composite microspheres according to claim 7, characterized in that, The catalyst includes one or more of N,N,N',N'-tetramethylethylenediamine and triethylamine; And / or, the amount of the catalyst used is 10-20 wt% of the mass of the reactants; And / or, the alkaline solution comprises 0.5~2wt% of an aqueous solution of NaHCO3 or Na2CO3.

9. The method for preparing supramolecular composite microspheres according to claim 1 or 7, characterized in that, The reaction temperature is 50~80℃; And / or, the reaction time is 2 to 24 hours.

10. The method for preparing supramolecular composite microspheres according to claim 1, characterized in that, The preparation method of the supramolecular composite microspheres includes: preparing an aqueous solution of a cationic supramolecular compound with water; mixing the aqueous solution of the cationic supramolecular compound with the anionic hydrogel microspheres; stirring continuously for 2-5 hours; filtering; and rinsing multiple times with deionized water to obtain the supramolecular composite.

11. The method for preparing supramolecular composite microspheres according to claim 10, characterized in that, The mass concentration of the aqueous solution of the cationic supramolecular compound is 2-30 wt%. And / or, the volume ratio of the cationic supramolecular compound aqueous solution to the anionic hydrogel microspheres is 2:1 to 200:

1.

12. The method for preparing supramolecular composite microspheres according to claim 1 or 10, characterized in that, The cationic supramolecular compounds include one or more derivatives of cyclodextrin, cucurbituril, calixarene, and cryptane after cationic modification.

13. A supramolecular composite microsphere, characterized in that, It is prepared using the supramolecular composite microsphere preparation method as described in any one of claims 1 to 12.

14. The supramolecular composite microspheres according to claim 13, characterized in that, The anionic hydrogel microspheres in the supramolecular composite microspheres have a pore diameter of 50~5000 nm.

15. The application of a supramolecular composite microsphere as described in any one of claims 1 to 12, characterized in that, The supramolecular composite microspheres are used to load drug molecules, which include one or more of macromolecular drugs, small molecule drugs, cationic drugs, and non-cationic drugs.

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