Zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres, their preparation methods and applications

Abstract

This invention relates to the field of biomedical materials technology, providing zeolite-polyvinyl alcohol (PVA) organic-inorganic composite embolization microspheres, their preparation method, and applications. The method involves preparing coagulation-functional nano-zeolite through ion exchange, dispersing the nano-zeolite in silicone oil to form a continuous phase, and using microfluidic technology to form W / O droplets between the PVA dispersion solution and the nano-zeolite-containing continuous phase. After cross-linking and curing using an organic acid catalyst, zeolite-PVA organic-inorganic composite embolization microspheres with both physical embolization and procoagulant functions are obtained. These microspheres, using cross-linked PVA as a matrix and uniformly distributed with specific functional nano-zeolite particles on the surface, possess both physical embolization and procoagulant functions. They show broad application prospects in tumor embolization therapy, vascular malformation embolization, and the treatment of hemorrhagic diseases, providing a novel and highly efficient embolization treatment solution for clinical use.

Description

Technical Field

[0001] This invention belongs to the field of biomedical materials technology, and particularly relates to zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres, their preparation methods, and applications. Background Technology

[0002] In recent years, embolic microspheres have played a crucial role in the treatment of tumors, vascular malformations, and hemorrhagic diseases as key materials in interventional medicine. Ideal embolic microspheres require good biocompatibility, precise size controllability, excellent monodispersity, and additional functional properties (such as drug loading and imaging). Polyvinyl alcohol (PVA) is widely used as a matrix material for embolic microspheres due to its excellent water solubility, biocompatibility, and spheroidizing properties. However, PVA microspheres prepared by traditional methods have limited functionality and a wide size distribution, making it difficult to meet the high-order requirements of modern embolization therapy for size uniformity and multifunctionality. Microfluidic technology, based on the precise control of multiphase fluids within micron-scale channels, can generate highly uniform, monodisperse droplets, providing a powerful technological platform for the preparation of high-performance composite embolic microspheres with precise size control and complex structures.

[0003] Traditional embolic microspheres primarily function as physical embolizers, with limited therapeutic potential. Combining functional nanomaterials with polyvinyl alcohol (PVA) microspheres is an effective strategy to enhance their performance. While nanozeolites possess excellent coagulation properties, they also present several challenges. For example, direct application in vivo leads to particle aggregation, potentially causing ectopic embolism or vascular stenosis over time. Furthermore, the extremely small size of nanoparticles and their uncontrollable distribution within the body make precise delivery to normal tissues difficult, and uncontrollable coagulation activity increases the risk of thrombosis. These factors prevent the direct application of nanozeolites in in vivo embolization therapy. Currently, although various drug-loaded PVA microspheres or inorganic composite microspheres have been reported, the technology for preparing nanozeolite-PVA organic-inorganic composite embolic microspheres with ultra-high monodispersity, precisely tunable size, and high drug loading capacity has yet to be reported. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres, their preparation method, and applications, with the aim of solving the problems mentioned in the background art.

[0005] In a first aspect, the present invention provides a method for preparing zeolite polyvinyl alcohol organic-inorganic composite embolic microspheres, comprising the following steps:

[0006] Step 1: Tetramethylammonium hydroxide, aluminum isopropoxide, LUDOX HS-40, sodium hydroxide, and water are mixed and reacted at 90°C. The reaction mixture is then allowed to stand and crystallized at 100°C. The cooled reaction product is centrifuged, the supernatant is discarded, the precipitate is collected and washed, and CaCl2 solution is added for multiple ion exchange treatments until Ca²⁺ ions are completely exchanged. The final precipitate is dried to obtain nano-zeolite.

[0007] Step 2: Prepare a continuous phase solution by mixing nano-zeolite with silicone oil, followed by shaking and ultrasonic treatment to obtain a continuous phase solution;

[0008] Step 3: Mix the polyvinyl alcohol solution with the crosslinking agent and acid catalyst, and shake to form a uniform dispersed phase solution. Load the dispersed phase solution and the continuous phase solution into syringes respectively, and place a portion of the continuous phase solution in a glass dish at 60°C as a curing medium. Driven by a micro-injection pump, the dispersed phase solution and the continuous phase are combined through a three-way tube to form W / O type droplets. The droplets are introduced into silicone oil at 60°C, and the curing reaction is completed under magnetic heating and stirring to obtain zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres.

[0009] Further, in step one, the mass ratio of tetramethylammonium hydroxide, aluminum isopropoxide, LUDOX HS-40, sodium hydroxide and water is 7.2-0.8 : 0.85-1.27 : 1.35-2.03 : 0.56-0.84 : 3.0-4.5.

[0010] Furthermore, in step two, nano-zeolite and silicone oil are mixed at a ratio of nano-zeolite:silicone oil = 1-5 mg: 1 ml.

[0011] Furthermore, in step three, the mass fraction of the polyvinyl alcohol solution is 2%-10%.

[0012] Furthermore, in step three, the crosslinking agent includes at least one of glutaraldehyde, glyoxal, formaldehyde, ethylene glycol diglycidyl ether, or polyethylene glycol diglycidyl ether.

[0013] Furthermore, in step three, the acid catalyst is 3-amino-5-[(hydroxymethyl)oxy]-4-[(sulfonylmethyl)oxymethyl]valerate.

[0014] Furthermore, in step three, the volume ratio of polyvinyl alcohol solution: crosslinking agent: acid catalyst is 8-12:0.5-1.5:0.5-1.5.

[0015] Secondly, the present invention provides zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres, which are prepared by the method for preparing zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres.

[0016] Furthermore, the zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres use cross-linked polyvinyl alcohol as a matrix to form the main body of the microspheres, and nano-zeolite particles are distributed on the surface of the main body of the microspheres.

[0017] Furthermore, the application of zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres in the preparation of medical devices for treating vascular embolism.

[0018] The present invention has the following beneficial effects:

[0019] (1) Coagulation-functional nano-zeolite (CaY type) was prepared by ion exchange. The nano-zeolite was dispersed in silicone oil to form a continuous phase. Microfluidic technology was used to form W / O droplets between the polyvinyl alcohol dispersion solution and the continuous phase containing nano-zeolite. After cross-linking and curing, zeolite-polyvinyl alcohol organic-inorganic composite embolization microspheres were prepared. These microspheres combine the good biocompatibility and elasticity of the polyvinyl alcohol matrix with the excellent coagulation function of CaY type zeolite. In vascular embolization treatment, they can achieve rapid and effective vascular occlusion and significantly improve embolization efficiency. In particular, the nano-zeolite not only has a high specific surface area and ordered pore structure, providing a large number of loading sites for drug molecules, which is conducive to achieving high drug loading and sustained release, but its regular pore structure also has a molecular sieving effect, which can achieve selective loading and controlled release of drugs.

[0020] (2) 3-Amino-5-[(hydroxymethyl)oxy]-4-[(sulfonylmethyl)oxymethyl]valeric acid is used. It is a multifunctional organic acid catalyst containing sulfonic acid, amino and carboxyl groups. Compared with traditional inorganic acid catalysts (such as hydrochloric acid and sulfuric acid), this organic acid catalyst is milder and can avoid excessive local acidity and uniformly regulate the cross-linking process, thereby obtaining microspheres with full morphology, uniform size and good dispersion. At the same time, this organic acid catalyst also has good biocompatibility, which can prevent the key coagulation sites (calcium ion release channels, porous adsorption structures) of nano-zeolite from being destroyed by strong acid, ensuring that the coagulation active sites are fully exposed, maintaining the coagulation function of nano-zeolite, and synergistically enhancing the therapeutic effect of embolization microspheres.

[0021] (3) The entire preparation process is mild, with good process repeatability, and does not require surface modification of zeolite. The process is simple and has good repeatability and scale-up potential. The zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres prepared by cross-linking and curing have broad application prospects in the fields of tumor embolization therapy, vascular malformation embolization and hemorrhagic disease treatment, providing a new and efficient embolization treatment solution for clinical use. Attached Figure Description

[0022] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0023] Figure 1This is a graph showing the DLS dynamic light scattering analysis results of CaY-type nanozeolite in Example 1 of this invention.

[0024] Figure 2 This is a transmission electron microscope image of CaY-type nanozeolite from Example 1 of the present invention. Scale bar: 200 μm.

[0025] Figure 3 These are scanning electron microscope images of the zeolite polyvinyl alcohol composite embolization microspheres (conventional acidic catalyst) prepared in Comparative Example 2 and the zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres (organic acidic catalyst) prepared in Example 1 of this invention, wherein:

[0026] Figure 3 In Example 2, A represents the microspheres prepared using hydrochloric acid as an acid catalyst. Scale bar: 100 μm.

[0027] Figure 3 In Example 1, B refers to the microspheres prepared using 3-amino-5-[(hydroxymethyl)oxy]-4-[(sulfonylmethyl)oxymethyl]valerate as an acid catalyst. Scale bar: 100 μm.

[0028] Figure 4 The figure shows the results of the in vitro coagulation performance verification test of Example 5 of the present invention, wherein:

[0029] Figure 4 A in the figure is a comparison of the time for complete coagulation of rabbit plasma catalyzed by polyvinyl alcohol embolization microspheres in Example 1 and zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres in Example 1.

[0030] Figure 4 Figure B in the diagram illustrates the complete coagulation state of rabbit plasma catalyzed by polyvinyl alcohol embolization microspheres in Example 1.

[0031] Figure 4 C in the figure represents the complete coagulation state of rabbit plasma catalyzed by zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres in Example 1.

[0032] Figure 5 Images showing ear vascular embolism and tissue changes in rabbits in the experimental and control groups of Example 5 of this invention, wherein:

[0033] Figure 5 In the figure, A is a healthy rabbit ear of a control group rabbit after being injected with polyvinyl alcohol embolized microspheres of control example 1;

[0034] Figure 5 B in the figure is the rabbit ear image on the first day after the control group rabbits were injected with polyvinyl alcohol embolized microspheres of Comparative Example 1;

[0035] Figure 5 C in the figure is the rabbit ear image of the control group rabbits on the sixth day after injection of polyvinyl alcohol embolized microspheres of Comparative Example 1;

[0036] Figure 5 D in the figure is the ear image of the control group rabbits on the eleventh day after injection of polyvinyl alcohol embolized microspheres of Comparative Example 1;

[0037] Figure 5 E in the figure is the rabbit ear image of the control group rabbits on the fourteenth day after injection of polyvinyl alcohol embolized microspheres of Comparative Example 1;

[0038] Figure 5 F in the figure represents the ear of a healthy rabbit in the experimental group after injection of zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres as described in Example 1.

[0039] Figure 5 G in the figure is the rabbit ear image on the first day after the rabbits in the experimental group were injected with zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres from Example 1.

[0040] Figure 5 H in the figure is the rabbit ear image on the sixth day after the rabbits in the experimental group were injected with zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres of Example 1;

[0041] Figure 5 In the image, I represents the ear of a rabbit on the eleventh day after injection of zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres from Example 1 into the experimental group of white rabbits.

[0042] Figure 5 J in the figure is the rabbit ear image on the fourteenth day after the rabbits in the experimental group were injected with zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres of Example 1.

[0043] Figure 6 This is a quantitative result of the ear vascular embolism and tissue changes in the experimental and control groups of rabbits in Example 5 of the present invention. Detailed Implementation

[0044] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0046] This invention provides a method for preparing zeolite polyvinyl alcohol organic-inorganic composite embolic microspheres, comprising the following steps:

[0047] Step 1: Tetramethylammonium hydroxide, aluminum isopropoxide, LUDOX HS-40, sodium hydroxide, and water are mixed and reacted at 90°C. The reaction mixture is then allowed to stand and crystallized at 100°C. The cooled reaction product is centrifuged, the supernatant is discarded, the precipitate is collected and washed, and CaCl2 solution is added for multiple ion exchange treatments until Ca²⁺ ions are completely exchanged. The final precipitate is dried to obtain nano-zeolite.

[0048] Step 2: Prepare a continuous phase solution by mixing nano-zeolite with silicone oil, followed by shaking and ultrasonic treatment to obtain a continuous phase solution;

[0049] Step 3: Mix the polyvinyl alcohol solution with the crosslinking agent and acid catalyst, and shake to form a uniform dispersed phase solution. Load the dispersed phase solution and the continuous phase solution into syringes respectively, and place a portion of the continuous phase solution in a glass dish at 60°C as a curing medium. Driven by a micro-injection pump, the dispersed phase solution and the continuous phase are combined through a three-way tube to form W / O type droplets. The droplets are introduced into silicone oil at 60°C, and the curing reaction is completed under magnetic heating and stirring to obtain zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres.

[0050] In some embodiments, in step one, the mass ratio of tetramethylammonium hydroxide, aluminum isopropoxide, LUDOX HS-40, sodium hydroxide, and water is 7.2-0.8 : 0.85-1.27 : 1.35-2.03 : 0.56-0.84 : 3.0-4.5.

[0051] In some embodiments, in step two, nano-zeolite and silicone oil are mixed at a ratio of nano-zeolite:silicone oil = 1-5 mg: 1 ml.

[0052] In some embodiments, in step three, the mass fraction of the polyvinyl alcohol solution is 2%-10%.

[0053] In some embodiments, in step three, the crosslinking agent includes at least one of glutaraldehyde, glyoxal, formaldehyde, ethylene glycol diglycidyl ether, or polyethylene glycol diglycidyl ether.

[0054] In some embodiments, in step three, the acid catalyst is 3-amino-5-[(hydroxymethyl)oxy]-4-[(sulfonylmethyl)oxymethyl]valerate.

[0055] In some embodiments, in step three, the volume ratio of polyvinyl alcohol solution: crosslinking agent: acid catalyst is 8-12:0.5-1.5:0.5-1.5.

[0056] In some embodiments, the present invention provides zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres, which are prepared by the method for preparing zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres.

[0057] In some embodiments, the zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres use cross-linked polyvinyl alcohol as a matrix to form the microsphere body, and nano-zeolite particles are distributed on the surface of the microsphere body. The particle size range of the nano-zeolite particles is 20-1000 nm, and the overall particle size range of the zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres is 50-1000 μm.

[0058] In some embodiments, the application of zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres in the preparation of medical devices for treating vascular embolism.

[0059] Example 1: Preparation of zeolite polyvinyl alcohol organic-inorganic composite embolic microspheres

[0060] (1) Preparation of CaY type nano zeolite: 9.0g tetramethylammonium hydroxide, 1.06g aluminum isopropoxide, 1.6875g LUDOXHS-40, 0.675ml sodium hydroxide and 3.75ml water were mixed and reacted at 90℃ for 1 hour. The mixture was then transferred to a reaction vessel and allowed to stand for 2 hours. The mixture was then crystallized at 100℃ for 2 hours. The reaction product was centrifuged and the precipitate was collected and washed with deionized water until the pH was 6-7. CaCl2 solution was added and stirred at room temperature for 10 hours. After centrifugation, the supernatant was discarded, the precipitate was collected and washed, and the ion exchange treatment was repeated twice to ensure complete Ca²⁺ ion exchange (the absence of precipitate was indicated by sodium carbonate test). Finally, the CaY type nano zeolite was obtained by drying.

[0061] The DLS dynamic light scattering analysis results of CaY-type nanozeolite are as follows: Figure 1 As shown in the figure, the hydrated particle size of CaY-type nanozeolite is approximately 140 nm, indicating that it exhibits good nanoscale properties in the dispersion. Transmission electron microscopy (TEM) images of CaY-type nanozeolite are shown below. Figure 2 As shown, the results indicate that the geometric size of the primary particles is concentrated in the range of 90-220 nm, with regular morphology and clear crystal structure. This result is consistent with the hydration kinetic diameter measured by DLS, which together confirm that the synthesized CaY zeolite has uniform nanoscale size and good dispersibility in the dispersion system, without serious irreversible agglomeration.

[0062] (2) Preparation of continuous phase solution: CaY type nano zeolite: silicone oil = 1mg: 1ml is mixed, and the zeolite particles are fully dispersed by shaking and ultrasonic treatment to obtain a continuous phase solution (oil phase).

[0063] (3) Preparation of composite embolization microspheres: 1 ml of 6% polyvinyl alcohol solution was mixed with 0.1 ml of glutaraldehyde and 0.1 mL of 0.2 M 3-amino-5-[(hydroxymethyl)oxy]-4-[(sulfonylmethyl)oxymethyl]valerate to form a dispersed phase solution (aqueous phase);

[0064] 3-Amino-5-[(hydroxymethyl)oxy]-4-[(sulfonylmethyl)oxymethyl]valeric acid is prepared from L-serine. The main process includes: using L-serine as a raw material, the OH group on the carboxyl group is first replaced with Cl, then with CN, and then the carbonyl CO is reduced to methylene CH2. After hydrolysis, CN is converted to carboxyl COOH to obtain 3-amino-4-hydroxybutyric acid; then the hydroxyl group at position 4 on 3-amino-4-hydroxybutyric acid is oxidized to an aldehyde group, and reacted with methoxymethanol (CH3OCH2OH) under alkaline conditions. After oxidation, the product is reacted with methoxymethanesulfonic acid (CH3OCH2SO3H). After dehydroxylation, the target product, 3-amino-5-[(hydroxymethyl)oxy]-4-[(sulfonylmethyl)oxymethyl]valeric acid, is obtained.

[0065] In the microfluidic device, a 2ml syringe is used to draw the dispersed phase solution and a 20ml syringe is used to draw the continuous phase solution. The syringes are connected to the corresponding inlets of a three-way connector through a thin tube and a conduit, respectively. At the same time, the outlet conduit is placed into the collection device. The microinjection pump pushes the 2ml syringe at a flow rate of 0.10ml / min and the 20ml syringe at a flow rate of 1.00ml / min. The dispersed phase solution and the continuous phase are combined through the three-way connector to form W / O type droplets. The microfluidic device adopts a three-way connector structure. The syringe carrying the dispersed phase solution is connected to one interface of the three-way connector through a thin tube, and the syringe carrying the continuous phase solution is connected to another interface through a conduit. The third interface is connected to the heated curing bath through a conduit.

[0066] The formed W / O type droplets were introduced into a glass dish containing silicone oil at 60°C through a conduit. The solidification reaction was completed under the action of a magnetic heating stirrer. Finally, the collected microspheres were washed and dried with petroleum ether and ethanol to obtain pure zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres.

[0067] Among them, 3-amino-5-[(hydroxymethyl)oxy]-4-[(sulfonylmethyl)oxymethyl]valerate was structurally identified and has the structural formula shown in formula (I):

[0068] Formula (I).

[0069] Example 2: Preparation of zeolite polyvinyl alcohol organic-inorganic composite embolic microspheres

[0070] (1) Preparation of CaY-type nano-zeolite: 10.0g tetramethylammonium hydroxide, 1.20g aluminum isopropoxide, 2.00g LUDOXHS-40, 0.80g sodium hydroxide and 4.2ml water were mixed and reacted at 90℃ for 1 hour. The mixture was then transferred to a reaction vessel and allowed to stand for 2 hours. The mixture was then crystallized at 100℃ for 2 hours. The reaction product was centrifuged and the precipitate was collected and washed with deionized water until the pH was 6-7. CaCl2 solution was added and stirred at room temperature for 10 hours. After centrifugation, the supernatant was discarded, the precipitate was collected and washed, and the ion exchange treatment was repeated twice to ensure complete Ca²⁺ ion exchange (the absence of precipitate was indicated by sodium carbonate test). Finally, the CaY-type nano-zeolite was obtained by drying.

[0071] (2) Preparation of continuous phase solution: CaY type nano zeolite: silicone oil = 3mg: 1ml is mixed, and the zeolite particles are fully dispersed by shaking and ultrasonic treatment to obtain a continuous phase solution.

[0072] (3) Preparation of composite embolization microspheres: Mix 1 ml of 8% (w / w) polyvinyl alcohol solution with 0.1 ml of... Glyoxal and 0.1 mL of 0.3 M 3-amino-5-[(hydroxymethyl)oxy]-4-[(sulfonylmethyl)oxymethyl]valeric acid were mixed to form a dispersed phase solution. In a microfluidic device, a 2 mL syringe was used to draw the dispersed phase solution and a 20 mL syringe was used to draw the continuous phase solution. The syringes were connected to the corresponding inlets of a three-way connector through a thin tube and a conduit, respectively, while the outlet conduit was placed into the collection device. A micro-injection pump pushed the 2 mL syringe at a flow rate of 0.10 mL / min and the 20 mL syringe at a flow rate of 1.00 mL / min. The dispersed phase solution and the continuous phase were combined through the three-way connector to form W / O type droplets. The formed W / O type droplets were introduced into a glass dish containing 60 °C silicone oil through a conduit. The solidification reaction was completed under the action of a magnetic heating stirrer. Finally, the collected microspheres were washed and dried with petroleum ether and ethanol to obtain pure zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres.

[0073] Example 3: Preparation of zeolite polyvinyl alcohol organic-inorganic composite embolic microspheres

[0074] (1) Preparation of CaY-type nano-zeolite: 7.5g tetramethylammonium hydroxide, 0.90g aluminum isopropoxide, 1.40g LUDOXHS-40, 0.60g sodium hydroxide and 3.2ml water were mixed and reacted at 90℃ for 1 hour. The mixture was then transferred to a reaction vessel and allowed to stand for 2 hours, followed by crystallization at 100℃ for 2 hours. After centrifugation, the precipitate was collected and washed with deionized water until the pH reached 6-7. CaCl2 solution was added, and the mixture was stirred at room temperature for 10 hours. After centrifugation, the supernatant was discarded, the precipitate was collected and washed, and this ion exchange treatment was repeated twice to ensure complete Ca²⁺ ion exchange (the absence of precipitate was used as a test by sodium carbonate). Finally, the CaY-type nano-zeolite was obtained by drying.

[0075] (2) Preparation of continuous phase solution: CaY type nano zeolite: silicone oil = 5mg: 1ml is mixed, and the zeolite particles are fully dispersed by shaking and ultrasonic treatment to obtain a continuous phase solution.

[0076] (3) Preparation of composite embolic microspheres: 1 ml of 4% polyvinyl alcohol solution was mixed with 0.08 ml of glutaraldehyde and 0.04 ml of... A dispersed phase solution was formed by mixing polyethylene glycol diglycidyl ether and 0.15 mL of 0.2 M 3-amino-5-[(hydroxymethyl)oxy]-4-[(sulfonylmethyl)oxymethyl]valerate. In a microfluidic device, a 2 mL syringe was used to draw the dispersed phase solution and a 20 mL syringe was used to draw the continuous phase solution. The syringes were connected to the corresponding inlets of a three-way connector through a thin tube and a conduit, respectively, while the outlet conduit was placed into a collecting device. A micro-injection pump pushed the 2 mL syringe at a flow rate of 0.10 mL / min and the 20 mL syringe at a flow rate of 1.00 mL / min. The dispersed phase solution and the continuous phase were combined through the three-way connector to form W / O droplets. The formed W / O droplets were introduced into a glass dish containing 60 °C silicone oil through a conduit. The solidification reaction was completed under the action of a magnetic heating stirrer. Finally, the collected microspheres were washed and dried with petroleum ether and ethanol to obtain pure zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres.

[0077] Comparative Example 1: Preparation of Polyvinyl Alcohol Embolizing Microspheres

[0078] (1) Forming and curing of microspheres: 1 mL of 6% polyvinyl alcohol aqueous solution was mixed with 0.1 mL of glutaraldehyde and 0.02 mL of 1M hydrochloric acid and stirred thoroughly to form a dispersed phase solution; at the same time, pure silicone oil was used as the continuous phase solution; in the microfluidic device, a 2 mL syringe was used to draw the dispersed phase solution and a 20 mL syringe was used to draw the continuous phase solution; the two syringes were connected to the two inlets of a three-way tube through a polytetrafluoroethylene capillary tube and a conduit, respectively, and the outlet of the three-way tube was connected to a glass dish containing 60℃ silicone oil (as a heating curing bath) through a conduit; the micro-injection pump was started to push the 2 mL syringe loaded with the dispersed phase at a flow rate of 0.10 mL / min and the 20 mL syringe loaded with the continuous phase at a flow rate of 1.00 mL / min. The two-phase fluids converge at the three-way pipe, and the dispersed phase forms uniform W / O type droplets under the shearing action of the continuous phase. The W / O type droplets flow into the silicone oil curing bath at 60°C with the continuous phase. Under the gentle stirring of the magnetic heating stirrer, polyvinyl alcohol undergoes a cross-linking reaction with glutaraldehyde under acid catalysis and is cured into spherical microspheres. The reaction lasts for about 1 hour to ensure complete curing.

[0079] (2) Post-treatment of microspheres: After solidification, the collected microspheres and mixed liquid were poured into a centrifuge tube. The supernatant was discarded by centrifugation. Then, the microspheres were washed repeatedly with petroleum ether and anhydrous ethanol to thoroughly remove residual silicone oil, unreacted crosslinking agent and acid catalyst. Finally, the pure microspheres were dried in a vacuum drying oven at 40°C to constant weight to obtain polyvinyl alcohol embolization microspheres.

[0080] Comparative Example 2: Preparation of Zeolite Polyvinyl Alcohol Composite Embolizing Microspheres

[0081] (1) Preparation of CaY type nano zeolite: 9.0g tetramethylammonium hydroxide, 1.06g aluminum isopropoxide, 1.6875g LUDOXHS-40, 0.675ml sodium hydroxide and 3.75ml water were mixed and reacted at 90℃ for 1 hour. The mixture was then transferred to a reaction vessel and allowed to stand for 2 hours. The mixture was then crystallized at 100℃ for 2 hours. The reaction product was centrifuged and the precipitate was collected and washed with deionized water until the pH was 6-7. CaCl2 solution was added and stirred at room temperature for 10 hours. After centrifugation, the supernatant was discarded, the precipitate was collected and washed, and the ion exchange treatment was repeated twice to ensure complete Ca²⁺ ion exchange (the absence of precipitate was indicated by sodium carbonate test). Finally, the CaY type nano zeolite was obtained by drying.

[0082] (2) Preparation of continuous phase solution: CaY type nano zeolite: silicone oil = 1mg: 1ml is mixed, and the zeolite particles are fully dispersed by shaking and ultrasonic treatment to obtain a continuous phase solution (oil phase).

[0083] (3) Preparation of composite embolization microspheres: 1 ml of 6% polyvinyl alcohol solution was mixed with 0.1 ml of glutaraldehyde and 0.02 ml of 2M sulfuric acid to form a dispersed phase solution; in a microfluidic device, a 2 ml syringe was used to draw the dispersed phase solution and a 20 ml syringe was used to draw the continuous phase solution. The syringes were connected to the corresponding inlets of the three-way tube through the thin tube and the conduit, respectively, and the outlet conduit was placed in the collection device. The micro-injection pump pushed the 2 ml syringe at a flow rate of 0.10 ml / min and the 20 ml syringe at a flow rate of 1.00 ml / min. The dispersed phase solution and the continuous phase were combined through the three-way tube to form W / O type droplets; the formed W / O type droplets were introduced into a glass dish containing 60℃ silicone oil through the conduit, and the solidification reaction was completed under the action of a magnetic heating stirrer. Finally, the collected microspheres were washed and dried with petroleum ether and ethanol to obtain pure zeolite polyvinyl alcohol composite embolization microspheres.

[0084] Scanning electron microscope images of the zeolite polyvinyl alcohol composite embolization microspheres (conventional acidic catalyst) prepared in Comparative Example 2 and the zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres (organic acidic catalyst) prepared in Example 1 are shown below. Figure 3 As shown, the results indicate that the zeolite-polyvinyl alcohol composite embolization microspheres prepared in Comparative Example 2 exhibited obvious damage and collapse on the surface, resulting in poor structural integrity. Some microspheres showed signs of rupture and denting. Figure 3 (A) The zeolite-polyvinyl alcohol organic-inorganic composite embolization microspheres prepared in Example 1 have nano-zeolite fillers uniformly distributed on their surface, exhibiting a clear surface enrichment structure, full spherical shape, smooth and intact surface, uniform size and good dispersion. Figure 3 (B in the middle).

[0085] The conventional acidic catalyst used in this embodiment is sulfuric acid. Another conventional acidic catalyst (hydrochloric acid) yielded scanning electron microspheres with the same results as those with sulfuric acid.

[0086] Example 4:

[0087] To verify the procoagulant properties and embolic effect of zeolite polyvinyl alcohol organic-inorganic composite embolic microspheres, in vitro procoagulant performance verification tests and in vivo effect evaluation tests using a rabbit ear central artery embolization model were conducted, as detailed below:

[0088] (1) In vitro coagulation performance verification test: Blood was collected from healthy rabbits, anticoagulated with sodium citrate, and platelet-rich plasma was obtained after centrifugation. The experiment was divided into two groups: polyvinyl alcohol embolization microsphere group and zeolite polyvinyl alcohol organic-inorganic composite embolization microsphere group; 70 μL of 0.1 mol / L CaCl2 solution was added to 200 μL of rabbit plasma to initiate the coagulation process, and then the same mass (10 mg) of polyvinyl alcohol embolization microspheres (Comparative Example 1) or zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres (Example 1) were added respectively. The plasma was immediately shaken at 37℃ and the time required for complete coagulation was recorded.

[0089] Results of in vitro coagulation performance verification test as follows Figure 4 As shown, the results indicate that the zeolite-polyvinyl alcohol organic-inorganic composite embolization group exhibits a strong procoagulant ability, with a significantly shorter clotting time than the polyvinyl alcohol embolization microsphere group. The average clotting time of the polyvinyl alcohol embolization microsphere group was 6.71 min, while the average clotting time of the zeolite-polyvinyl alcohol organic-inorganic composite embolization microsphere group was shortened to 3.88 min. This is attributed to the large specific surface area of ​​the nano-zeolite and the Ca²⁺ carried on its surface, which can efficiently activate the coagulation reaction and adsorb platelets, while the simple polyvinyl alcohol embolization microspheres only have physical adsorption effects and limited procoagulant activity. This demonstrates that the zeolite-polyvinyl alcohol organic-inorganic composite embolization prepared in this invention has excellent active procoagulant function.

[0090] (2) In vivo efficacy evaluation of rabbit central auricular artery embolization model: New Zealand white rabbits were selected and fixed after anesthesia; polyvinyl alcohol embolization microspheres (comparative example 1) and zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres (example 1) were dispersed in a mixed solution of glycerol and physiological saline to prepare embolization suspensions; 0.3 mL of zeolite polyvinyl alcohol organic-inorganic composite embolization microsphere suspension was precisely injected into the central auricular artery of the experimental group rabbits, and the same amount of polyvinyl alcohol embolization microsphere suspension was injected into the control group rabbits; the embolization status and tissue changes of the ear blood vessels were continuously monitored and recorded immediately after injection and on day 1, day 6, day 11 and day 14 of injection in the control group and experimental group through visual observation and digital photographic analysis.

[0091] Images of ear vascular embolism and tissue changes in the experimental and control groups of rabbits are shown below. Figure 5As shown, the results indicate that the control group (polyvinyl alcohol embolization microspheres) required a longer time to induce embolism, exhibited significant early recanalization after embolization, had a smaller embolization area, and insufficient persistence. In stark contrast, the experimental group (zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres) rapidly induced local thrombus formation after injection into the target vessel, achieving rapid and thorough vascular occlusion. Throughout the 14-day observation period, the experimental group maintained a stable and persistent embolization state without significant recanalization. The reliability, thoroughness, and persistence of its embolization effect were significantly superior to those of the control group. This demonstrates that the zeolite polyvinyl alcohol organic-inorganic composite embolization prepared in this invention can achieve highly efficient and persistent vascular occlusion in clinical treatment, greatly improving the efficacy of embolization.

[0092] The quantitative results of ear vascular embolism and tissue changes in the experimental and control groups of rabbits are as follows: Figure 6 As shown, the results indicate that the tissue necrosis rate in the experimental group (zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres) rapidly increased after embolization and continued to rise, maintaining a stable and persistent upward trend throughout the 14-day observation period, reaching a high level of approximately 20%-25% by the end of the observation period, with no obvious recanalization observed. In contrast, the tissue necrosis rate in the control group (polyvinyl alcohol embolization microspheres) remained at a lower level (approximately 5%-10%), with a sluggish increase, indicating that its embolization effect was incomplete. This quantitative data fully demonstrates that the zeolite polyvinyl alcohol organic-inorganic composite embolization microspheres provided by this invention are significantly superior to traditional polyvinyl alcohol embolization microspheres in terms of the reliability, thoroughness, and durability of the embolization effect, enabling efficient and sustained vascular occlusion in clinical treatment, thereby greatly improving the efficacy of embolization.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing zeolite polyvinyl alcohol organic-inorganic composite embolic microspheres, characterized in that: The method comprises the following steps: Step one: mixing tetramethylammonium hydroxide, aluminum isopropoxide, LUDOX HS-40, sodium hydroxide and water, reacting at 90°C, then standing the reaction mixture and crystallizing at 100°C; centrifuging the cooled reaction product, discarding the supernatant, collecting the precipitate and washing, then adding CaCl2 solution for ion exchange treatment multiple times until the Ca²⁺ ion exchange is complete; Drying the final precipitate to obtain nano zeolite; Step two: preparing a continuous phase solution, mixing the nano zeolite and silicone oil, then oscillating and ultrasonic treating to obtain the continuous phase solution; Step three: mixing the polyvinyl alcohol solution, crosslinking agent and acid catalyst, oscillating to form a uniform dispersed phase solution; loading the dispersed phase solution and the continuous phase solution into syringes respectively, and taking part of the continuous phase solution into a glass dish at 60°C as a solidification medium; under the push of a microsyringe pump, the dispersed phase solution and the continuous phase are combined through a three-way pipe to form W / O type droplets; the droplets are introduced into 60°C silicone oil, and the solidification reaction is completed under magnetic heating stirring to obtain zeolite polyvinyl alcohol organic-inorganic composite embolism microspheres; The acid catalyst is 3-amino-5-[(hydroxymethyl)oxy]-4-[(sulfonic acid methyl)oxymethyl] pentanoic acid, which has a structural formula as shown in formula (I): Formula (I).

2. The production method according to claim 1, characterized by: In step one, the mass ratio of tetramethylammonium hydroxide, aluminum isopropoxide, LUDOX HS-40, sodium hydroxide and water is 7.2-0.8:0.85-1.27:1.35-2.03:0.56-0.84:3.0-4.

5.

3. The production method according to claim 2, characterized by: In step two, the nano zeolite and silicone oil are mixed in a mass ratio of 1-5 mg:1 ml.

4. The production method according to claim 3, characterized by: In step three, the mass fraction of the polyvinyl alcohol solution is 2%-10%.

5. The production method according to claim 4, characterized by: In step three, the crosslinking agent includes at least one of glutaraldehyde, glyoxal, formaldehyde, ethylene glycol diglycidyl ether or polyethylene glycol diglycidyl ether.

6. The production method according to claim 5, characterized by: In step three, the volume ratio of the polyvinyl alcohol solution, the crosslinking agent and the acid catalyst is 8-12:0.5-1.5:0.5-1.

5.

7. Zeolite polyvinyl alcohol organic-inorganic composite embolizing microspheres, characterized by: The zeolite polyvinyl alcohol organic-inorganic composite embolism microspheres are prepared by the preparation method of any one of claims 1-6.

8. The zeolite polyvinyl alcohol organic-inorganic composite embolic microspheres as described in claim 7, characterized in that: The zeolite polyvinyl alcohol organic-inorganic composite embolism microspheres have crosslinked polyvinyl alcohol as a matrix to constitute a microsphere body, and nano zeolite particles are distributed on the surface of the microsphere body.

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