A vascular closure glue composition, a method for preparing the same

Abstract

This invention discloses a vascular occlusive gel composition, comprising a first component and a second component. The first component comprises cysteine-modified carboxymethyl cellulose and dopamine-modified carboxymethyl cellulose. The second component comprises 3-aminophenylboronic acid-modified carboxymethyl cellulose and hydroxyethyl methacrylate-modified carboxymethyl cellulose. This invention also discloses a vascular occlusive gel prepared from the above composition and its preparation method. This invention employs a two-component system that can rapidly crosslink to form a sealing hydrogel with excellent tissue adhesion, mechanical properties, and biocompatibility, effectively achieving physical occlusion of diseased blood vessels. Furthermore, all components exhibit good biocompatibility and biodegradability, ensuring medical safety.

Description

Technical Field

[0001] This invention relates to the field of biomedical materials, specifically to a vascular sealing adhesive composition and its preparation method. Background Technology

[0002] Endovenous treatment techniques mainly include radiofrequency ablation and endovenous laser ablation. Compared with traditional open surgery, thermal ablation significantly reduces the incidence of postoperative complications, alleviates pain, shortens recovery time, and improves patients' quality of life, thereby reducing treatment-related morbidity.

[0003] To overcome the inherent risks of thermal damage and the reliance on tumescent anesthesia in thermal ablation techniques, a novel class of non-thermal, non-tumescent therapies has been developed, including a technique for venous occlusion via intravascular injection of cyanoacrylate medical adhesive. The cyanoacrylate adhesive undergoes a rapid polymerization reaction upon contact with blood, achieving adhesion and occlusion of the vein wall. Clinical studies have shown that its venous occlusion rate is comparable to traditional thermal ablation, demonstrating certain therapeutic efficacy.

[0004] However, with the accumulation of clinical application experience, the limitations of cyanoacrylate medical adhesives have gradually become apparent. Taking the cyanoacrylate medical adhesive involved in Chinese patent document CN 114796591 A as an example, its drawbacks are mainly reflected in the following aspects: First, adverse reactions are relatively common, mainly including phlebitis, allergic reactions, foreign body granulomas, and intracavitary adhesive-induced thrombosis. Among them, foreign body granulomas and allergic reactions are closely related to the chronic inflammation caused by the permanent implantation of the adhesive. Second, there is a risk of adhesive embolism; the adhesive may extravasate or migrate, leading to serious complications such as pulmonary embolism. In addition, studies have shown that cyanoacrylate injection causes a high degree of pathological damage to the blood vessel wall, which, although contributing to vascular fibrosis, may also trigger a stronger inflammatory response. As a permanent implant material, its long-term degradation products in vivo and long-term safety still need further observation.

[0005] Carboxymethyl cellulose (CMC)-based bioadhesives offer unique advantages as a novel, non-thermal, non-swelling therapeutic material. CMC is a promising cellulose derivative. Due to its unique surface properties, mechanical strength, tunable hydrophilicity, viscous properties, availability and abundance of raw materials, low-cost synthesis processes, and numerous comparative advantages, it is now widely used. It exhibits good biocompatibility and biodegradability, gradually degrading and being absorbed in vivo. The degradation products are non-toxic, avoiding the risks of chronic foreign body granulomas and allergic reactions associated with permanent foreign body implantation. Existing CMC medical colloidal materials primarily focus on applications in skin and wound repair, such as the sodium CMC medical bioadhesive solution disclosed in patent document CN104645407A, which is mainly targeted at the repair of human skin and epithelial tissue in wounds, promoting healing through drug-loaded microspheres. To date, there are no mature products or clinical application schemes for directly using carboxymethyl cellulose-based bio-adhesive for filling and occluding varicose veins, and existing carboxymethyl cellulose (CMC) medical adhesives cannot be directly applied to fill and occlude varicose veins. Summary of the Invention

[0006] This invention is made to solve the above-mentioned problems, and aims to provide a vascular sealing adhesive composition and vascular sealing adhesive, which is particularly suitable for venous vascular closure in the treatment of varicose veins. The vascular sealing adhesive adopts a two-component system, which can be mixed with existing three-way connectors and injected through catheters. It can quickly cross-link to form a sealing hydrogel with excellent tissue adhesion, mechanical properties and biocompatibility, effectively achieving physical closure of diseased blood vessels.

[0007] In a first aspect, the present invention provides a vascular occlusive adhesive composition comprising a first component and a second component; the first component comprising: cysteine-modified carboxymethyl cellulose (CMC-Cys) and dopamine-modified carboxymethyl cellulose (CMC-dopamine, or CMC-CD); the second component comprising: 3-aminophenylboronic acid-modified carboxymethyl cellulose (CMC-PBA) and hydroxyethyl methacrylate-modified carboxymethyl cellulose (CMC-HEMA).

[0008] Furthermore, the mass ratio of the first component to the second component is 0.8:1 to 1.2:1; even further, the mass ratio of the first component to the second component is 1:1.

[0009] Further, in the first component, the mass ratio of cysteine-modified carboxymethyl cellulose to dopamine-modified carboxymethyl cellulose is 0.5:1 to 4:1. Even further, in the first component, the mass ratio of cysteine-modified carboxymethyl cellulose to dopamine-modified carboxymethyl cellulose is 0.5:1 to 2:1. As a specific preferred embodiment, in the first component, the mass ratio of cysteine-modified carboxymethyl cellulose to dopamine-modified carboxymethyl cellulose is 1:1.

[0010] Furthermore, in the second component, the mass ratio of 3-aminophenylboronic acid-modified carboxymethyl cellulose to hydroxyethyl methacrylate-modified carboxymethyl cellulose is 1:1 to 4:1. Even further, in the second component, the mass ratio of 3-aminophenylboronic acid-modified carboxymethyl cellulose to hydroxyethyl methacrylate-modified carboxymethyl cellulose is 1:1 to 3:1, including but not limited to 1:1, 1.5:1, 2:1, 2.5:1, 3:1, etc.

[0011] A venous vascular occlusive adhesive composition, which is the vascular occlusive adhesive composition described in any of the above-mentioned technical solutions.

[0012] Furthermore, a vein vascular sealing adhesive composition suitable for varicose veins is the vascular sealing adhesive composition described in any of the above-mentioned technical solutions.

[0013] In a second aspect, the present invention provides a vascular sealing adhesive, which is obtained by reacting the first component and the second component as described in any of the above technical solutions.

[0014] Further, the first component and the second component are reacted in a solvent to obtain the final product.

[0015] Further, the solvent is one or more mixed solvents selected from buffer solution, physiological saline, and water for injection. Even further, the solvent is one or more mixed solvents selected from phosphate buffer, 2-(N-morpholino)ethanesulfonic acid buffer, physiological saline, and water for injection.

[0016] A venous vascular sealing adhesive, which is the vascular sealing adhesive described in any of the above technical solutions.

[0017] Furthermore, a vein vascular sealing adhesive suitable for varicose veins is the vascular sealing adhesive described in any of the above technical solutions.

[0018] A third aspect of the present invention provides a method for preparing the vascular sealing adhesive described in any of the above-mentioned technical solutions, comprising:

[0019] The first component is dissolved in a solvent to obtain a first mixed solution;

[0020] The second component is dissolved in a solvent to obtain a second mixed solution;

[0021] The first mixture and the second mixture are mixed to obtain the vascular sealing gel.

[0022] Furthermore, a method for preparing a vein vascular sealing adhesive for varicose veins is provided, comprising the vein vascular sealing adhesive being a two-component system, prepared through the following steps:

[0023] (1) Preparation of the first component: carboxymethyl cellulose modified with cysteine ​​(CMC-Cys) and carboxymethyl cellulose modified with dopamine (CMC-dopamine) are mixed and dissolved in a solvent to obtain the first mixed solution;

[0024] (2) Preparation of the second component: Carboxymethyl cellulose (CMC-PBA) modified with 3-aminophenylboronic acid and carboxymethyl cellulose (CMC-HEMA) modified with hydroxyethyl methacrylate are mixed and dissolved in a solvent to obtain a second mixed solution;

[0025] (3) Mix the first component and the second component to obtain the vein vascular sealing adhesive.

[0026] Furthermore, in step (3), two syringes containing the first component and the second component are connected by a three-way connector to ensure that the two components are mixed evenly during the injection process.

[0027] Furthermore, in the specific implementation of step (3): the first component and the second component are respectively loaded into two independent syringes and connected by a three-way connector. Before injection, the syringe is pushed to make the two components mix evenly when passing through the three-way connector, and then injected into the target vein through the catheter. The mixed solution cross-links in situ in the body to form a blocking hydrogel.

[0028] Further, the mass-volume percentage concentration of the first mixed solution is 2-10% (g / mL). Even further, the mass-volume percentage concentration of the first mixed solution is 3-8% (g / mL); specifically, the mass-volume percentage concentration of the first mixed solution is 4-6%.

[0029] Further, the mass-volume percentage concentration of the second mixed solution is 2-10% (g / mL). Even further, the mass-volume percentage concentration of the second mixed solution is 3-8% (g / mL); specifically, the mass-volume percentage concentration of the first mixed solution is 4-6%.

[0030] This invention employs a two-component reactive hydrogel system, in which chemically modified carboxymethyl cellulose (CMC) derivatives are formulated into two components. In the first component, CMC-Cys provides thiol and amino groups from cysteine, which can form disulfide bonds with thiol groups on the tissue surface or amide bonds with carboxyl groups, achieving covalent adhesion. Simultaneously, its thiol groups can also undergo a thiol-alkene click reaction with the hydroxyethyl methacrylate double bond of CMC-HEMA in the second component, achieving chemical cross-linking between components. CMC-dopamine (CMC-DA) provides catechol groups (derived from dopamine), enabling self-crosslinking (see...). Figure 4 The second component, CMC-PBA, provides phenylboronic acid groups (derived from 3-aminophenylboronic acid), which can form dynamically reversible phenylboronic ester bonds with the catechol groups of dopamine (see...). Figure 6 This process enables rapid gelation, while CMC-HEMA provides hydroxyethyl methacrylate groups, which can enhance the gel's network structure through interactions such as hydrogen bonding. After the two components are mixed via a three-way connector, the thiol and amino groups of cysteine ​​covalently bind to corresponding groups on the tissue surface, while the thiol groups crosslink with the HEMA double bonds (see...). Figure 5 Together, they achieve robust vascular wall occlusion; at the same time, the cross-linking of dopamine and PBA, along with the auxiliary reinforcement of HEMA, form a hydrogel with appropriate mechanical strength and toughness.

[0031] Furthermore, this invention introduces dopamine into the CMC framework, utilizing its catechol structure to mimic mussel adhesive proteins, thereby endowing the sealing adhesive with strong adhesion to the vascular endothelial tissue in a moist physiological environment, ensuring the firmness and durability of the sealing.

[0032] Furthermore, this invention introduces 3-aminophenylboronic acid (PBA) onto the CMC backbone, enabling the phenylboronic acid groups in CMC-PBA to rapidly form reversible phenylboronic acid ester bonds with the catechol groups of dopamine under physiological pH conditions. This not only achieves rapid cross-linking and curing of the adhesive, preventing it from being washed away by blood flow, but also provides the gel with self-healing ability and a certain degree of compliance due to its dynamic reversibility.

[0033] Furthermore, in the two-component system of the present invention, the presence of thiol and amino groups of cysteine ​​provides the ability to covalently bind with tissue proteins. At the same time, the thiol group can also chemically crosslink with HEMA double bonds, further enhancing the cohesive strength of the gel and effectively resisting the blood flow pressure in venous blood vessels.

[0034] Compared to traditional varicose vein treatments (such as laser, radiofrequency, or sclerotherapy) or single-component occlusion materials, the venous occlusion adhesive provided by this invention has advantages such as ease of use (ready to mix and use), rapid in-situ cross-linking, strong adhesion, adjustable mechanical properties, and good biocompatibility. By adjusting the ratio of the two components, the gelation time and mechanical properties of the gel can be controlled to adapt to veins of different diameters and blood flow conditions, achieving precise and effective vascular occlusion.

[0035] In some embodiments, in the first mixed solution of step (1), the mass ratio of CMC-Cys to CMC-dopamine is (0.5~2):1.

[0036] CMC-Cys provides cross-linking activity and tissue adhesion sites, while CMC-dopamine primarily provides wet adhesion properties. Controlling their ratio balances the adhesive's tissue adhesion strength and cohesive energy. A higher CMC-Cys ratio enhances covalent bonding with tissue and cross-linking density with HEMA, but may reduce gel flexibility; a higher CMC-dopamine ratio improves wet adhesion and the gel's dynamic reversibility. In this example, the mass ratio is controlled at (0.5~2):1 to ensure the adhesive maintains good cohesive strength and suitable flexibility while possessing strong tissue adhesion, meeting the requirements for vein occlusion.

[0037] In some embodiments, in the second mixed solution of step (2), the mass ratio of CMC-PBA to CMC-HEMA is (1~3):1.

[0038] CMC-PBA, as the main crosslinking component, drives gelation through its interaction with dopamine. CMC-HEMA, as an auxiliary reinforcing component, enhances the physical entanglement between molecular chains through hydrogen bonding via its hydroxyethyl side chains. Its double bonds can also chemically crosslink with the thiol groups of CMC-Cys, improving the gel's toughness and structural density. Controlling the ratio of these two components allows for precise regulation of the gel's crosslinking density, mechanical strength, and swelling behavior. In this example, the mass ratio is controlled at (1~3):1 to ensure that the adhesive rapidly gels after injection and forms a three-dimensional network structure with sufficient mechanical strength, effectively occluding blood vessels.

[0039] In some embodiments, the solvent for the first or second component is phosphate buffer, physiological saline, or water for injection.

[0040] Using biocompatible buffer solutions or saline solutions as solvents can ensure the safety of the glue system for vascular tissues, avoid the toxic side effects caused by residual organic solvents, and maintain the stability and activity of each component.

[0041] In some embodiments, the mixing volume ratio of the first component and the second component is 1:1.

[0042] Equal-volume mixing via a T-joint is the most common method for two-component medical adhesives, offering a simple and easy-to-master procedure for clinicians. This equal-volume mixing design ensures that reactive groups (such as cysteine ​​thiol / amino groups with tissue surface groups, thiol with HEMA double bonds, and catechol with PBA) contact in the designed proportions, achieving optimal cross-linking and sealing performance.

[0043] In some embodiments, in step (3), after the two components are mixed, the gelation transition is completed within 10 seconds to 5 minutes.

[0044] Controlling gelation time is crucial for clinical procedures. Gelping too quickly can lead to catheter blockage or inaccurate injection sites; gelling too slowly may result in dilution or flushing away in the bloodstream. The system of this invention, by adjusting the degree of substitution and ratio of its components, can control the gelation time within the range of 10 seconds to 5 minutes, providing physicians with an ample operational window while ensuring rapid formation and sealing of the adhesive once it reaches the target location.

[0045] Further, the cysteine-modified carboxymethyl cellulose is obtained by a condensation reaction of cysteine ​​and carboxymethyl cellulose or its salt in the presence of a coupling agent; the dopamine-modified carboxymethyl cellulose is obtained by a condensation reaction of dopamine and carboxymethyl cellulose or its salt in the presence of a coupling agent; the 3-aminophenylboronic acid-modified carboxymethyl cellulose is obtained by a condensation reaction of 3-aminophenylboronic acid and carboxymethyl cellulose or its salt in the presence of a coupling agent; the hydroxyethyl methacrylate-modified carboxymethyl cellulose is obtained by a condensation reaction of hydroxyethyl methacrylate and carboxymethyl cellulose or its salt in the presence of a coupling agent. In this invention, the carboxymethyl cellulose can be directly used, or a carboxymethyl cellulose salt, such as sodium carboxymethyl cellulose, or any combination thereof. Further, the weight-average molecular weight of the carboxymethyl cellulose or its salt is 100,000 to 400,000 Da.

[0046] Furthermore, the coupling agent includes 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC); the reaction system may also contain carbodiimide and N-hydroxysuccinimide (NHS) and / or DMAP and / or antioxidants, as needed. The reaction solvent for the condensation reaction is selected from one or more of 2-(N-morpholino)ethanesulfonic acid buffer solution and phosphate buffer solution. The amount of EDC or NHS, DMAP or antioxidant added is the conventional amount.

[0047] Furthermore, in preparing cysteine-modified carboxymethyl cellulose, the mass ratio of cysteine ​​to carboxymethyl cellulose or its salt is 0.2~0.4:1; further, in preparing cysteine-modified carboxymethyl cellulose, sodium carboxymethyl cellulose is used; even further, the mass ratio of cysteine ​​to sodium carboxymethyl cellulose is 0.2~0.3:1; more specifically, it is preferably 0.24:1.

[0048] Furthermore, in preparing dopamine-modified carboxymethyl cellulose, the mass ratio of dopamine or its salt to carboxymethyl cellulose or its salt is 0.07~1.2:1; further, in preparing dopamine-modified carboxymethyl cellulose, dopamine hydrochloride and sodium carboxymethyl cellulose are used; even further, the mass ratio of dopamine hydrochloride to sodium carboxymethyl cellulose is 0.08~0.1:1; more specifically, it is preferably 0.09:1.

[0049] Furthermore, in preparing 3-aminophenylboronic acid-modified carboxymethyl cellulose, the mass ratio of 3-aminophenylboronic acid to carboxymethyl cellulose or its salt is 0.07~1.2:1; further, in preparing 3-aminophenylboronic acid-modified carboxymethyl cellulose, sodium carboxymethyl cellulose is used; further, the mass ratio of 3-aminophenylboronic acid to sodium carboxymethyl cellulose is 0.08~0.1:1; more specifically, preferably 0.09:1.

[0050] Furthermore, in preparing hydroxyethyl methacrylate-modified carboxymethyl cellulose, the mass ratio of hydroxyethyl methacrylate to carboxymethyl cellulose or its salt is 0.3~0.8:1; furthermore, in preparing hydroxyethyl methacrylate-modified carboxymethyl cellulose, sodium carboxymethyl cellulose is used; furthermore, the mass ratio of hydroxyethyl methacrylate to sodium carboxymethyl cellulose is 0.5:1.

[0051] As one embodiment, the method for preparing the cysteine-modified carboxymethyl cellulose includes: dissolving carboxymethyl cellulose or its salt (such as sodium salt) in a buffer solution (such as MES buffer solution), reacting it with cysteine ​​in the presence of a coupling agent (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, with the addition of N-hydroxysuccinimide), and obtaining the cellulose after purification. In some embodiments, the preparation method of CMC-Cys in step (1) includes: dissolving carboxymethyl cellulose (or its salt, both referred to as CMC) in a buffer solution, adding N-hydroxysuccinimide, and then adding a coupling agent (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and also adding N-hydroxysuccinimide) to convert the carboxyl group on CMC into an NHS active ester intermediate; then adding cysteine ​​to the activated solution, and finally grafting cysteine ​​onto the CMC backbone via an amide bond in the presence of the above coupling agent, dialysis purification after the reaction (dialysis with a dialysis bag with a molecular weight cutoff of 8k-14kDa), and lyophilization to obtain CMC-Cys.

[0052] In this embodiment, cysteine ​​is grafted onto the CMC molecular chain via an amidation reaction. The thiol and amino groups of cysteine ​​endow the adhesive with the ability to form disulfide or amide bonds with the tissue surface. At the same time, the thiol groups can also undergo efficient thiol-alkene click chemistry with the double bonds of HEMA. This is the key to achieving a strong covalent bond between the adhesive and the blood vessel wall, as well as chemical cross-linking between components.

[0053] Further, the preparation method of the dopamine-modified carboxymethyl cellulose includes: dissolving carboxymethyl cellulose or its salt (such as sodium salt) in a buffer solution, reacting it with dopamine in the presence of a coupling agent, and obtaining it after purification. Further still, in some embodiments, the preparation method of CMC-dopamine in step (1) includes: dissolving carboxymethyl cellulose or its salt (such as sodium salt) in a buffer solution (MES), adding EDC·HCl and NHS for activation; dissolving dopamine hydrochloride and vitamin C (as an antioxidant) in the MES buffer solution; slowly adding the dopamine solution dropwise to the activated CMC solution, adjusting the pH, and grafting dopamine hydrochloride onto the CMC backbone via amide bonds in the presence of the above coupling agent; dialysis purification after the reaction, and lyophilization to obtain CMC-dopamine.

[0054] Furthermore, in the preparation of the dopamine-modified carboxymethyl cellulose, the reaction is carried out under conditions of pH 5.3-5.6 (which can be performed in MES buffer). The dopamine can be provided in the form of dopamine hydrochloride, and the reaction is carried out in the absence of light and / or in the presence of antioxidants. After the reaction is complete, glycine is added to terminate the reaction.

[0055] In the examples, dopamine was grafted onto the CMC molecular chain via an amidation reaction. The catechol groups of dopamine are the source of its super-strong wet adhesion, enabling it to bind to various inorganic / organic surfaces (including biological tissues) through a variety of forces such as hydrogen bonding, metal complexation, π-π stacking, and covalent bonding, thus endowing the adhesive with excellent water-resistant adhesion properties.

[0056] Further, the preparation method of 3-aminophenylboronic acid modified carboxymethyl cellulose includes: dissolving carboxymethyl cellulose or its salt (such as sodium salt) in a buffer solution, reacting it with 3-aminophenylboronic acid in the presence of a coupling agent, and obtaining it after purification. In some embodiments, the preparation method of CMC-PBA in step (2) includes: dissolving carboxymethyl cellulose or its salt (such as sodium salt) in a buffer solution (MES), adding EDC·HCl and NHS for activation; then dissolving 3-aminophenylboronic acid in the MES buffer solution to obtain a PBA solution; slowly adding the PBA solution dropwise to the activated CMC solution, controlling the pH value; in the presence of the above coupling agent, grafting 3-aminophenylboronic acid or its derivative onto the CMC backbone through an amide bond; after the reaction is completed, adding glycine to terminate the reaction; dialysis purification and lyophilization to obtain CMC-PBA.

[0057] Further, the CMC-PBA is prepared, and the reaction is carried out at pH 5.4-5.6 (optionally in MES buffer solution).

[0058] In the examples, 3-aminophenylboronic acid was introduced into the CMC via an amidation reaction, thereby grafting phenylboronic acid groups onto the CMC backbone. Phenylboronic acid is a functional group that has the ability to specifically recognize and reversibly bind to diols (such as catechol of dopamine), and can form phenylboronic ester bonds at physiological pH. It is a core component for constructing dynamic cross-linked networks and achieving rapid gelation.

[0059] Furthermore, the preparation method of carboxymethyl cellulose modified with hydroxyethyl methacrylate includes: dissolving sodium carboxymethyl cellulose in anhydrous dimethyl sulfoxide, adding a coupling agent (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride) and N-hydroxysuccinimide and 4-dimethylaminopyridine) to convert the carboxyl group on CMC into an NHS active ester intermediate; then adding hydroxyethyl methacrylate to the activated solution, reacting under nitrogen protection and light-protected conditions to react hydroxyethyl methacrylate with carboxymethyl cellulose or its salt, purifying (dialyzing with an 8k-14kDa dialysis bag), and lyophilizing to obtain dry carboxymethyl cellulose (CMC-HEMA) modified with hydroxyethyl methacrylate.

[0060] Furthermore, after the above reactions are completed, unreacted small molecule reagents and byproducts are removed using a dialysis bag with a molecular weight cutoff of 8k-14kDa, thereby enriching the product. The dialyzed product is then pre-frozen at -80°C and subsequently freeze-dried to obtain the corresponding modified carboxymethyl cellulose dry material.

[0061] In a second aspect, the present invention provides a venous vascular sealing adhesive for varicose veins, wherein the venous vascular sealing adhesive is prepared according to the preparation method described in the first aspect, and is a two-component system comprising a first component and a second component, wherein the two components are mixed to form a hydrogel with tissue adhesion and vascular sealing functions.

[0062] In this invention, the sealing hydrogel formed after mixing the two components has a storage modulus of 500-5000 Pa, and in in vitro tests simulating physiological blood flow conditions, it can withstand a blood impact pressure of not less than 50 mmHg without displacement or rupture.

[0063] A third aspect of the present invention provides an application of a venous vascular closure adhesive for varicose veins, wherein the venous vascular closure adhesive prepared by the preparation method described in the first aspect or the venous vascular closure adhesive described in the second aspect is used to prepare a medical device or drug for treating varicose veins.

[0064] Specifically, through interventional methods, a dual syringe containing the first and second components is connected to a catheter. Under image guidance, the catheter tip is delivered to the target varicose vein. The syringe is then pushed to mix the two components as they pass through the three-way connector and are injected through the catheter. The mixture cross-links in situ within the vein to form a hydrogel, thereby physically blocking the varicose vein, making it organized, and eventually absorbed by the body or permanently occluded.

[0065] Specifically, the medical device or drug is injected into the target vein via catheter intervention, where it cross-links in situ to form a sealing adhesive; wherein the viscosity of the vein sealing adhesive is such that it is compatible with 4F to 8F series catheters for smooth injection.

[0066] By implementing the above technical solution, the present invention has the following beneficial effects:

[0067] This invention employs a two-component reaction system, grafting functional groups such as cysteine ​​(Cys), dopamine, phenylboronic acid (derived from 3-aminophenylboronic acid), and hydroxyethyl methacrylate onto a carboxymethyl cellulose backbone. This design allows the first and second components to be mixed via a three-way connector (see...). Figure 1This adhesive can rapidly undergo multiple cross-linking reactions: on the one hand, the thiol and amino groups of cysteine ​​covalently bind to corresponding groups on the tissue surface, while the thiol groups chemically cross-link with HEMA double bonds, giving the adhesive strong tissue adhesion and cohesive strength; on the other hand, dopamine forms dynamic phenylboronic acid ester bonds with phenylboronic acid, achieving rapid in-situ gelation of the adhesive; simultaneously, the HEMA groups enhance the physical cross-linking network through hydrogen bonds. This synergistic effect of multiple mechanisms allows the adhesive to rapidly form and firmly adhere to the inner wall of blood vessels under the physiological environment of blood flushing, achieving effective physical occlusion of varicose veins.

[0068] This invention uses carboxymethyl cellulose as the main framework, which possesses excellent biocompatibility and biodegradability. The introduced functional groups, such as cysteine, dopamine, phenylboronic acid (derived from 3-aminophenylboronic acid), and HEMA, do not produce significant cytotoxicity when properly designed. After fulfilling its sealing function, the adhesive gradually degrades over time, and the degradation products are harmless to the human body, avoiding the long-term risks associated with permanent implants.

[0069] This invention presents a ready-to-use two-component liquid system, administered via catheter injection, which is convenient, minimally invasive, and can perfectly fill irregularly shaped blood vessels. Compared to existing sclerotherapy (prone to recurrence and requiring pressure bandaging) or thermal ablation (requiring anesthesia and carrying the risk of nerve damage), the sealing adhesive of this invention offers a new approach to physical sealing, which is expected to simplify the procedure and improve treatment success rate and safety.

[0070] This invention allows for convenient adjustment of gelation time, gel strength, adhesion, and degradation rate by adjusting the proportions of each component of the CMC derivative, thereby enabling personalized design for veins of different diameters and blood flow velocities to meet diverse clinical needs.

[0071] The viscosity and curing properties of the carboxymethyl cellulose-based colloid of this invention can be precisely controlled, enabling controlled intravascular filling and occlusion, significantly reducing the risk of off-target embolism. Furthermore, this type of material does not require tumescent anesthesia and can be directly and precisely injected through a catheter, simplifying the procedure and increasing patient comfort.

[0072] Finally, the degradation of carboxymethyl cellulose-based colloids can provide a suitable matrix environment for vascular wall repair, potentially promoting physiological healing rather than simple inflammatory fibrosis, thereby further reducing the incidence of long-term complications. Therefore, carboxymethyl cellulose-based bio-adhesives represent an important development direction for next-generation minimally invasive treatment of varicose veins. Attached Figure Description

[0073] Figure 1 This is a schematic diagram of the glue mixing device used in this invention;

[0074] Figure 2This is an HE-stained image of a slice obtained during the in vitro simulated occlusion performance test of this invention;

[0075] Figure 3 This is a statistical graph of cell viability obtained from the biocompatibility test of this invention;

[0076] Figure 4 This is a schematic diagram of the CMC-DA self-crosslinking reaction;

[0077] Figure 5 This is a schematic diagram of a click chemistry reaction between mercapto-olefins;

[0078] Figure 6 This is a schematic diagram of the dynamic cross-linking reaction of phenylboronic acid esters.

[0079] Figure 7 This is the proton NMR spectrum of CMC-PBA.

[0080] Figure 8 This is the proton NMR spectrum of CMC-DA.

[0081] Figure 9 This is the hydrogen NMR spectrum of CMC-Cys.

[0082] Figure 10 This is the hydrogen NMR spectrum of CMC-HEMA. Detailed Implementation

[0083] To make the technical means, creative features, objectives and effects of this invention easy to understand, the invention will be specifically described below in conjunction with embodiments and accompanying drawings.

[0084] Example 1

[0085] Preparation of cysteine-modified carboxymethyl cellulose (CMC-Cys):

[0086] (1) Add 1g of sodium carboxymethyl cellulose (CMC) with a molecular weight of 250,000 to 100mL of 2-(N-morpholino)ethanesulfonic acid (MES) buffer solution and stir at 200rpm for 2-4 hours at 4℃ to fully dissolve it.

[0087] (2) First, add 0.11g of N-hydroxysuccinimide (NHS) to the above solution and stir for 5 minutes; then add 0.18g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl) and continue stirring at 4℃ for 60 minutes to carry out the activation reaction, so that the carboxyl group on CMC is converted into the NHS active ester intermediate.

[0088] (3) Add 0.24g of cysteine ​​(Cys) to the activated solution and continue stirring at room temperature (25℃) for 18 hours to allow the amino group of cysteine ​​to undergo amidation reaction with the NHS active ester on CMC and graft it onto the CMC skeleton.

[0089] (4) The solution after the reaction is placed into a dialysis bag with a molecular weight cutoff of 8k-14kDa and dialyzed in deionized water for 3 days to remove unreacted small molecule reagents and byproducts.

[0090] (5) The dialysis product was pre-frozen at -80℃ and then freeze-dried for 48 hours to obtain cysteine-modified carboxymethyl cellulose (CMC-Cys) dry material (NMR spectrometry results are shown in [reference]). Figure 9 ).

[0091] It should be noted that after the reaction in step (2) is completed, the NHS active ester intermediate purified product can be obtained by dialysis and lyophilization, denoted as "CMC-NHS", which can be directly used in other subsequent examples.

[0092] Example 2

[0093] Preparation of carboxymethyl cellulose modified with hydroxyethyl methacrylate (CMC-HEMA):

[0094] (1) Add 1 g of sodium carboxymethyl cellulose (CMC) with a molecular weight of 250,000 to 100 mL of anhydrous dimethyl sulfoxide (DMSO) and stir at 200 rpm for 4-6 hours at room temperature (25°C) to fully dissolve or evenly disperse it (if the dissolution is incomplete, it can be heated at 50°C to assist dissolution, and then cooled to room temperature).

[0095] (2) Add 0.18 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl), 0.11 g of N-hydroxysuccinimide (NHS) and 0.12 g of 4-dimethylaminopyridine (DMAP) to the above solution in sequence, and continue to stir and activate at room temperature for 30 minutes to convert the carboxyl group on CMC into the NHS active ester intermediate.

[0096] (3) Add 0.5 g of hydroxyethyl methacrylate (HEMA) to the activated solution and continue stirring for 24 hours at room temperature (25°C) under nitrogen protection and light protection to allow the hydroxyl groups of HEMA to undergo esterification with the NHS active ester on CMC and graft onto the CMC skeleton.

[0097] (4) The solution after the reaction is placed into a dialysis bag with a molecular weight cutoff of 8k-14k Da. First, it is dialyzed in 50% ethanol aqueous solution for 24 hours (the dialysate is changed every 8 hours), and then dialyzed in deionized water for 48 hours (the dialysate is changed every 12 hours) to remove unreacted HEMA, EDC, NHS, DMAP and by-products.

[0098] (5) The dialysis product was pre-frozen at -80℃ and then freeze-dried for 48 hours to obtain carboxymethyl cellulose (CMC-HEMA) dry material modified with hydroxyethyl methacrylate (NMR spectrometry results are shown in [reference]). Figure 10 ).

[0099] Example 3

[0100] Preparation of dopamine-modified carboxymethyl cellulose (CMC-dopamine)

[0101] (1) Add 1g of sodium carboxymethyl cellulose (CMC) with a molecular weight of 250,000 to 100mL of MES buffer solution and stir at 200rpm for 2-4 hours at 4℃ to fully dissolve it.

[0102] (2) Add 0.18g EDC·HCl to the above solution first, then add 0.11g NHS, and stir at 4℃ and 200rpm for 20 minutes to activate it.

[0103] (3) Weigh 0.09g of dopamine hydrochloride and 0.0025g of vitamin C (as an antioxidant), dissolve them in 5mL of MES buffer solution, prepare and use immediately to obtain dopamine solution and store it away from light.

[0104] (4) Slowly add the prepared dopamine solution to the activated CMC solution in step (2), and control the addition time to about 10 minutes. During the reaction, continue to add MES buffer solution to maintain the pH value of the system in the range of 5.3-5.6. React at 200 rpm for 3 hours at room temperature.

[0105] (5) Add 0.075 g of glycine and stir for 10 minutes to terminate the reaction. Transfer the reaction solution into a dialysis bag with a molecular weight cutoff of 8 kDa and dialyze in deionized water for 3 days.

[0106] (6) The dialysis product was pre-frozen at -80°C and then freeze-dried for 48 hours to obtain dopamine-modified carboxymethyl cellulose (CMC-DA) dry material (NMR spectrometry results are shown in [reference]). Figure 8 ).

[0107] Example 4

[0108] Preparation of 3-aminophenylboronic acid modified carboxymethyl cellulose (CMC-PBA)

[0109] (1) Add 1g of sodium carboxymethyl cellulose (CMC) with a molecular weight of 250,000 to 100mL of MES buffer solution and stir at 200rpm for 2-4 hours at 4℃ to fully dissolve it.

[0110] (2) Add 0.18g EDC.HCl to the above solution first, then add 0.11g NHS, and stir at 4℃ and 200rpm for 20 minutes to activate it.

[0111] (3) Weigh 0.09g of 3-aminophenylboronic acid (PBA) and dissolve it in 5mL of MES buffer solution to obtain PBA solution.

[0112] (4) Slowly add the PBA solution to the activated CMC solution in step (2), and control the addition time to about 10 minutes. During the reaction, maintain the pH value of the system in the range of 5.4-5.6, and react at 200 rpm for 3 hours at room temperature.

[0113] (5) Add 0.075 g of glycine and stir for 10 minutes to terminate the reaction. Transfer the reaction solution into a dialysis bag with a molecular weight cutoff of 8 k-14 kDa and dialyze for 2 days.

[0114] (6) The dialysis product was pre-frozen at -80°C and then freeze-dried for 48 hours to obtain carboxymethyl cellulose (CMC-PBA) dry material modified with 3-aminophenylboronic acid (NMR spectrometry results are shown in [reference]). Figure 7 ).

[0115] Example 5

[0116] Formulation of two-component venous vascular occlusion adhesive components

[0117] (1) Preparation of the first component: CMC-Cys prepared in Example 1 and CMC-DA prepared in Example 3 were mixed at a mass ratio of 1:1 and dissolved in physiological saline to obtain a first mixed solution with a total concentration of 5% (w / v, g / ml, the same below).

[0118] (2) Prepare the second component:

[0119] The CMC-PBA prepared in Example 4 and the CMC-HEMA prepared in Example 2 were mixed at a mass ratio of 2:1 and dissolved in physiological saline to obtain a second mixed solution with a total concentration of 5% (w / v) (the corresponding glue system is referred to as "Example 5-2").

[0120] Adjust the mass ratio of CMC-PBA to CMC-HEMA to 1:1 and 3:1 respectively, and repeat the above steps to obtain a second mixed solution with a total concentration of 5% (w / v) (the corresponding glue systems are referred to as "Example 5-1" and "Example 5-3" respectively).

[0121] Comparative Example 1

[0122] Preparation of Cys-free sealing adhesive components:

[0123] (1) The first component and the second component were prepared according to the method of Example 5, except that CMC-Cys was not added to the first component, and only CMC-DA was used as the first component.

[0124] Comparative Example 2

[0125] Preparation of PBA-free sealing adhesive components:

[0126] (1) The first component and the second component were prepared according to the method of Example 5, except that CMC-PBA was not added to the second component, and only CMC-HEMA was used as the second component.

[0127] Comparative Example 3

[0128] Preparation of dopamine-free vein sealing adhesive components

[0129] The first and second components were prepared according to the method of Example 5, except that the CMC-dopamine prepared in Example 3 was not added to the first component. Instead, only the CMC-Cys prepared in Example 1 was used as the sole solute in the first component. That is, CMC-Cys was dissolved in physiological saline at the same total concentration (5% w / v) to obtain the first mixed solution. The second component was prepared in the same way as in Example 5 (CMC-PBA to CMC-HEMA mass ratio 2:1, total concentration 5% w / v).

[0130] Comparative Example 4

[0131] Unmodified CMC solution

[0132] Add 1g of sodium carboxymethyl cellulose (CMC) with a molecular weight of 250,000 to 20ml of deionized water and dissolve it completely to obtain a CMC solution with a concentration of 5% w / v.

[0133] Performance testing

[0134] 1. Gelization time test

[0135] The first and second components prepared in Example 5 were respectively loaded into two 1mL syringes and connected via a three-way connector. The syringes were then rapidly pushed to mix the two components at a 1:1 volume ratio and extrude the mixture. The adhesive mixing device is as follows: Figure 1 As shown in Table 1. The gelation time was determined using the inverted test tube method: the mixed solution was quickly added to the vial, and the vial was tilted every 5 seconds to observe whether the solution flowed. The time when the liquid surface stopped flowing was recorded as the gelation time. The test results are shown in Table 1.

[0136] The results showed that the gelation time of the venous vascular occlusion adhesive of the present invention could be effectively controlled by adjusting the mass ratio of CMC-PBA to CMC-HEMA in the second component. The gelation time could be controlled within the range of 20 to 120 seconds, meeting the needs of clinical operation. The adhesive obtained without the Cys component had a gelation time of more than 300 seconds, and the gel strength was weak. The mixture without the PBA component failed to form a stable gel for a long time (>10 minutes), and the fluidity remained very strong; while the control system without dopamine could not form a gel quickly, confirming that the phenylboronic acid ester bond formed between PBA and dopamine is the key mechanism for the rapid gelation of this system.

[0137] Table 1. Gelation time of venous vascular occlusion adhesives with different formulations

[0138]

[0139] 2. Tissue adhesion performance test

[0140] Fresh porcine aorta was collected, the adventitia and adipose tissue were peeled off, and the samples were cut into 2 cm × 2 cm pieces and soaked in physiological saline for later use. The first and second components were prepared according to the formula in Example 5 with a mass ratio of CMC-PBA:CMC-HEMA = 2:1 (wherein the first component contains CMC-Cys prepared in Example 1 and CMC-dopamine prepared in Example 3). The two components were mixed through a three-way connector, and 50 μL was immediately applied to the surface of one piece of porcine aortic tissue. Another piece of porcine aortic tissue was quickly placed on top, with an overlap area of ​​1 cm × 1 cm. Slight pressure was applied to ensure adhesion, and the mixture was incubated in a 37 ℃ incubator for 30 minutes. An overlap shear test was performed using a universal testing machine at a tensile speed of 5 mm / min. The maximum load was recorded, and the adhesion strength was calculated. The test results are shown in Table 2.

[0141] The results showed that the adhesion strength of Comparative Example 3, which did not contain dopamine, was 0.6 ± 0.4, which was much lower than that of Examples 5-2 and Comparative Example 1 (16.8 kPa), which contained both dopamine and cysteine ​​(CMC-Cys), confirming that the wet adhesion ability of dopamine is crucial for enhancing tissue adhesion.

[0142] Table 2. Tissue adhesion strength of venous vascular occlusion adhesive

[0143]

[0144] 3. In vitro simulated occlusion performance test

[0145] Construction of an in vitro venous vessel simulation device: The venous vessel sealing adhesive prepared in Example 5-2 was injected into the dissected venous vessel specimen through a catheter, with an injection volume of 0.5 mL. After gentle pressing for 30 seconds, it was flushed with physiological saline at a rate of 20 ml / min. The retention of the adhesive, the gel formation state, and the sealing effect were observed in the simulated blood flow environment.

[0146] Test results showed that the adhesive gelled in situ within 30 seconds after injection, forming a white columnar hydrogel that completely blocked the silicone tube lumen. No gel displacement or detachment was observed under continuous flow of saline solution, demonstrating stable sealing performance. Figure 2 The vascular pathology sections after the experiment show that the occlusion effect is good and obvious. As a control, after the glue prepared in Comparative Example 1 (without Cys) was injected, it was partially dispersed by the flowing saline, and the resulting gel block was small and failed to completely seal the lumen; after the glue prepared in Comparative Example 2 (without PBA) was injected, due to slow gelation, most of it was washed away by the flowing saline and could not form an effective occlusion.

[0147] 4. Biocompatibility testing (cytotoxicity testing)

[0148] Following ISO 10993-5 standards, the biocompatibility of the venous vascular sealing adhesive of this invention was characterized using the CCK-8 Cell Counting Kit by co-culturing the sample extract with L929 mouse fibroblasts in vitro. Cells cultured in ordinary culture medium were used as a negative control group. First, the venous vascular sealing adhesive was prepared according to Examples 5-2. After curing, an extraction solution (0.2 g / mL, extraction for 24 h) was prepared under aseptic conditions at 37°C. The extraction solution was sterilized through a 0.22 μm filter membrane and then supplemented with 10% fetal bovine serum. L929 mouse fibroblasts (cell concentration = 1 × 10⁻⁶ cells) were then used. 4 Cells ( / mL) were seeded in 96-well cell culture plates and cultured at 37°C and 5% CO2 for 24 hours. The culture medium was then removed, and 100 μL of extraction buffer was added for further culture. After 24 h, 48 h, and 72 h of culture, 10 μL of CCK-8 solution was added to each well, and the cells were incubated for 4 hours. The absorbance (OD) was measured at 450 nm using a microplate reader. Cell viability was calculated using formula (1):

[0149] (1)

[0150] Where As represents the absorbance of the experimental group, Ab represents the absorbance of the blank well, and Ac represents the absorbance of the negative control group.

[0151] Test results are as follows Figure 3As shown, cell viability (relative cell growth rate (RGR)) at each time point was greater than 90%, indicating that the venous vascular occlusion adhesive of the present invention is non-cytotoxic and has good biocompatibility.

[0152] As can be seen from the above embodiments and comparative examples, the two-component venous occlusion adhesive provided by the present invention achieves rapid and controllable gelation, excellent wet tissue adhesion, and good biocompatibility by grafting functional groups such as cysteine ​​(providing thiol and amino groups), dopamine, phenylboronic acid, and hydroxyethyl methacrylate onto a carboxymethyl cellulose backbone. By adjusting the ratio of each component, the gelation time and mechanical properties of the adhesive can be effectively controlled to meet the clinical needs of varicose vein occlusion treatment.

Claims

1. A vascular sealing adhesive composition, characterized in that, Includes the first component and the second component; The first component comprises: cysteine-modified carboxymethyl cellulose and dopamine-modified carboxymethyl cellulose; the second component comprises: 3-aminophenylboronic acid-modified carboxymethyl cellulose and hydroxyethyl methacrylate-modified carboxymethyl cellulose.

2. The vascular sealing adhesive composition according to claim 1, characterized in that, The mass ratio of the first component to the second component is 0.8:1 to 1.2:

1.

3. The vascular sealing adhesive composition according to claim 1, characterized in that, In the first component, the mass ratio of cysteine-modified carboxymethyl cellulose to dopamine-modified carboxymethyl cellulose is 0.5:1 to 4:1; in the second component, the mass ratio of 3-aminophenylboronic acid-modified carboxymethyl cellulose to hydroxyethyl methacrylate-modified carboxymethyl cellulose is 1:1 to 4:

1.

4. The vascular sealing adhesive composition according to claim 1, characterized in that, The cysteine-modified carboxymethyl cellulose, dopamine-modified carboxymethyl cellulose, 3-aminophenylboronic acid-modified carboxymethyl cellulose, and hydroxyethyl methacrylate-modified carboxymethyl cellulose are obtained by condensation reactions of cysteine, dopamine, 3-aminophenylboronic acid, and hydroxyethyl methacrylate with carboxymethyl cellulose or their salts under the action of corresponding coupling agents.

5. The vascular sealing adhesive composition according to claim 4, characterized in that, When preparing cysteine-modified carboxymethyl cellulose, the mass ratio of cysteine ​​to carboxymethyl cellulose or its salt is 0.2~0.4:1; when preparing dopamine-modified carboxymethyl cellulose, the mass ratio of dopamine or its salt to carboxymethyl cellulose or its salt is 0.07~1.2:1; when preparing 3-aminophenylboronic acid-modified carboxymethyl cellulose, the mass ratio of 3-aminophenylboronic acid to carboxymethyl cellulose or its salt is 0.07~1.2:1; when preparing hydroxyethyl methacrylate-modified carboxymethyl cellulose, the mass ratio of hydroxyethyl methacrylate to carboxymethyl cellulose or its salt is 0.3~0.8:

1.

6. The vascular sealing adhesive composition according to claim 4, characterized in that, The carboxymethyl cellulose or its salts have a weight-average molecular weight of 100,000 to 400,000 Da.

7. A vascular sealing adhesive, characterized in that, It is obtained by reacting the first component and the second component as described in any one of claims 1 to 6.

8. The vascular sealing adhesive according to claim 7, characterized in that, The first and second components are obtained by reacting in a solvent.

9. The vascular sealing adhesive according to claim 8, characterized in that, The solvent is one or more mixed solvents selected from phosphate buffer, 2-(N-morpholino)ethanesulfonic acid buffer, physiological saline, and water for injection.

10. A method for preparing the vascular sealing adhesive according to any one of claims 7 to 9, characterized in that: The first component is dissolved in a solvent to obtain a first mixed solution; The second component is dissolved in a solvent to obtain a second mixed solution; The first mixture and the second mixture are mixed to obtain the vascular sealing gel.

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