CN116059434A

CN116059434A - Biomedical tissue adhesive and preparation method thereof

Info

Publication number: CN116059434A
Application number: CN202211723502.8A
Authority: CN
Inventors: 刘子骁; 徐传艳; 程文悦; 王妍妍
Original assignee: Zhuoruan Medical Technology Suzhou Co ltd; Shanghai Excellence Medical Technologies Co ltd
Current assignee: Zhuoruan Medical Technology Suzhou Co ltd; Shanghai Excellence Medical Technologies Co ltd
Priority date: 2022-12-30
Filing date: 2022-12-30
Publication date: 2023-05-05

Abstract

The invention relates to the technical field of medical materials, in particular to a biomedical tissue adhesive and a preparation method thereof. The present application provides a biomedical tissue adhesive whose raw materials include a prepolymer and a polyphenol compound, the prepolymer including a combination of one or more of polyvinyl alcohol, acrylic acid and N-hydroxysuccinimide acrylate. The biomedical tissue adhesive provided by the invention can be adhered to a wet and moist tissue surface quickly and durably, has good biocompatibility, and is simple and controllable in clinical implementation conditions.

Description

Biomedical tissue adhesive and preparation method thereof

Technical Field

The invention belongs to the technical field of medical materials, and particularly relates to a biomedical tissue adhesive and a preparation method thereof.

Background

Wound healing is an important issue facing surgery, and after tissue damage, the formation of new tissue and the remodeling of tissue function can take as long as several months to one year, becoming an important factor in assessing whether surgery is successful. At present, the surgical operation mainly adopts physical closure technologies such as suture lines, suture nails and the like, but the closure technologies can cause secondary wounds and inflammatory reactions after operation in the operation process, and are difficult to apply to the physical closure technologies of tissues with complex structures. In contrast, the tissue adhesive has the characteristics of simple operation, short operation time, rapid wound healing and the like, and has wide application prospect. Despite the potential advantages of tissue adhesives over conventional suturing techniques, existing tissue adhesives still have some limitations: slow adhesion kinetics, low mechanical strength and poor interfacial bonding to wet biological tissue. For example, alpha-cyanoacrylates cure rapidly, but have low mechanical strength and are prone to toxic degradation products in physiological environments. Fibrinogen adhesives have good biocompatibility and degradability, but slow cure speed, low adhesive strength, and potential risk of viral infection. The hydrogel is a material with high water content and three-dimensional structure, is similar to biological tissues, has good biocompatibility, and various forms, and can be suitable for complex tissues. At present, various hydrogels have been developed for wound repair, but long-term practice shows that hydrogel adhesives still have the problems of low adhesive property, low adhesion speed, low mechanical property due to easy water absorption, and the like, which cannot be matched with tissues.

In addition, when a moist wound surface such as an in vivo tissue is involved, water molecules on the tissue surface hinder diffusion of adhesive molecules, and cannot bond with groups of the tissue. Either commercial tissue adhesives or hydrogel adhesives exhibit non-adhesion to tissue or low adhesion strength, i.e., are not effective in stopping bleeding or closing the wound. The ideal medical tissue adhesive should satisfy the following conditions: safe, nontoxic, non-carcinogenic, good and durable adhesive strength in wet environment, good biocompatibility, and gradual degradation and absorption in tissues.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention aims to provide the biomedical tissue adhesive and the preparation method thereof, and the biomedical tissue adhesive prepared by the synergistic effect of the acrylic acid, the polyvinyl alcohol, the N-hydroxysuccinimide acrylate and the polyphenol compound has the advantages of quick and lasting adhesion to moist and wet tissue surfaces, good biocompatibility, simple and controllable clinical implementation conditions and can be used for solving the problems in the prior art.

To achieve the above and other related objects, a first aspect of the present invention provides a biomedical tissue adhesive, the raw materials of which include a prepolymer including a combination of one or more of polyvinyl alcohol, acrylic acid, and N-hydroxysuccinimide acrylate, and a polyphenol compound.

In any embodiment of the present application, the concentration of the polyvinyl alcohol in the solution of the prepolymer is 3% -15% (w/w), and the alcoholysis degree of the polyvinyl alcohol is 75% or more.

In any of the embodiments herein, the concentration of acrylic acid in the solution of the prepolymer is 15% to 30% (w/w).

In any of the embodiments herein, the N-hydroxysuccinimide acrylate is present in the solution of the prepolymer at a concentration of 0.1% to 2% (w/w)

In any embodiment of the present application, the polyphenol compound is selected from one or more of tannic acid, catechol derivative pyrogallol, pyrogallol derivative, dopamine derivative, caffeic acid derivative, gallic acid derivative, catechin derivative.

In any of the embodiments herein, the concentration of the solution of the polyphenol compound is from 0.5% to 8% (w/w).

In any of the embodiments herein, the prepolymer further comprises a crosslinking agent and/or a photoinitiator.

In any embodiment of the present application, the cross-linking agent comprises one or more of a group consisting of a methacrylic acid anhydrified gelatin, polyethylene glycol diacrylate N, N' -methylenebisacrylamide.

In any embodiment of the present application, the photoinitiator comprises α -ketoglutarate and/or Irgacure 2959.

In any of the embodiments herein, the concentration of the crosslinking agent in the solution of the prepolymer is 0.01% to 0.1% (w/w).

In any of the embodiments herein, the concentration of the photoinitiator in the solution of the prepolymer is from 0.05% to 0.5% (w/w).

The second aspect of the present application provides a method for preparing the biomedical tissue adhesive, comprising the following steps:

1) Proportioning, stirring and mixing the polyvinyl alcohol, the acrylic acid N-hydroxysuccinimide ester, the cross-linking agent and the photoinitiator according to the proportion relation of the first aspect, so as to obtain a prepolymer solution;

2) Photo-crosslinking the prepolymer solution obtained in the step 1) to obtain hydrogel;

3) Soaking the hydrogel obtained in the step 2) in a polyphenol compound solution to obtain an adhesive precursor;

4) Drying the adhesive precursor in the step 3) to obtain the biomedical tissue adhesive.

In any embodiment of the present application, in step 1), the stirring time is 4 to 12 hours.

In any embodiment of the present application, in step 2), the photo-crosslinking reaction time is 5 to 20min.

In any embodiment of the present application, in step 3), the soaking treatment is performed under a dark condition, and the soaking treatment time is 12-48 hours.

In any embodiment of the present application, the drying is freeze-drying and/or vacuum-drying.

In a third aspect, the present application provides the use of the biomedical tissue adhesive or the preparation method in the preparation of a medical adhesive material.

The beneficial effects of the invention are as follows:

1. the medical tissue adhesive provided by the invention can quickly absorb moisture and retain water for a long time on the moist and wet tissue surface, can quickly and permanently adhere to the tissue surface, achieves the aim of closing a wound without a suture, and has simple and controllable clinical implementation conditions.

According to the invention, acrylic acid and polyvinyl alcohol are used as molecular frameworks, so that a three-dimensional porous gel topological network structure is constructed, the material can quickly absorb and moisten tissue surface liquid, and initial weak connection is formed through hydroxyl on the surface of the material and hydroxyl on the surface of the tissue. The first strong binding site which generates covalent reaction with amino groups on the surface of the tissue is constructed by carrying out N-hydroxysuccinimide surface grafting modification on the hydroxyl groups of acrylic acid and polyvinyl alcohol. The polyhydric phenol groups are introduced into the network structure to form multiple hydrogen bonding, so that the tissue adhesion gel topological network structure is stabilized, the biomechanical strength of the material is improved, and meanwhile, the introduced polyhydric phenol groups can react with amino groups and sulfhydryl groups on the surface of the tissue to generate Schiff base reaction and Michael addition reaction to form second strong bonding sites, so that the tissue bonding strength is further improved.

2. The medical tissue provided by the invention is subjected to aftertreatment by using low-concentration tannic acid, so that the swelling rate of the tissue adhesive is obviously reduced.

Natural polyphenols such as tannic acid have the characteristics of low cytotoxicity, antioxidation, antibacterial activity and the like, and can form non-covalent bonds with a polymer skeleton through hydrogen bonding, so that the overall mechanical strength is enhanced, and the swelling rate of a tissue adhesive is remarkably reduced; at the same time, the adhesive property with various surfaces is enhanced through the actions of hydrogen bond, ionic bond, pi-pi accumulation and the like.

3. The medical tissue adhesive provided by the invention is completely degradable and has good biocompatibility.

Drawings

Fig. 1 shows the scanning electron microscope results of example 1 and comparative example 1. Fig. 1A is a cross-sectional scanning electron microscope of example 1, and fig. 1B is a cross-sectional scanning electron microscope of comparative example 1.

Fig. 2 shows fourier infrared spectra of example 1 and comparative example 1.

Detailed Description

Before the embodiments of the invention are explained in further detail, it is to be understood that the invention is not limited in its scope to the particular embodiments described below; it is also to be understood that the terminology used in the examples of the invention is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention; in the description and claims of the invention, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

The "range" disclosed herein is defined in terms of lower and upper limits, with a given range being defined by the selection of a lower and an upper limit, the selected lower and upper limits defining the boundaries of the particular range. Ranges that are defined in this way can be inclusive or exclusive of the endpoints, and any combination can be made, i.e., any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a particular parameter, it is understood that ranges of 60 to 110 and 80 to 120 are also contemplated. Furthermore, if the minimum range values 1 and 2 are listed, and if the maximum range values 3,4 and 5 are listed, the following ranges are all contemplated: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In this application, unless otherwise indicated, the numerical ranges "a-b" represent shorthand representations of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed throughout, and "0-5" is only a shorthand representation of a combination of these values. When a certain parameter is expressed as an integer of 2 or more, it is disclosed that the parameter is, for example, an integer of 2, 3,4, 5, 6, 7, 8, 9, 10, 11, 12 or the like.

All steps of the present application may be performed sequentially or randomly, preferably sequentially, unless otherwise indicated. For example, the method comprises steps 1) and 2), meaning that the method may comprise steps 1) and 2) performed sequentially, or may comprise steps 2) and 1) performed sequentially.

Where numerical ranges are provided in the examples, it is understood that unless otherwise stated herein, both endpoints of each numerical range and any number between the two endpoints are significant both in the numerical range. Unless defined otherwise, 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 belongs. The present invention may be implemented using any method, apparatus and materials similar or equivalent to those described in the embodiments of the present invention, according to the knowledge of those skilled in the art and the description of the present invention, in addition to the specific methods, apparatus and materials used in the embodiments.

Unless otherwise indicated, the experimental methods, detection methods, and preparation methods disclosed in the present invention employ conventional techniques in the art, such as pharmacy, pharmacoanalytics, pharmaceutical chemistry, analytical chemistry, molecular biology, biochemistry, and related fields. These techniques are well described in the prior art.

In a first aspect, the present application provides a biomedical tissue adhesive, the biomedical tissue adhesive comprising a raw material comprising a prepolymer and a polyphenol compound, the prepolymer includes a combination of one or more of polyvinyl alcohol, acrylic acid, and N-hydroxysuccinimide acrylate. The above raw materials may be dissolved in deionized water, an aqueous solution, or an organic solvent to form a polyphenol compound solution or a prepolymer solution. The aqueous solution includes physiological solution including physiological saline, wilt's solution Le Shi solution, and tai's solution, etc., and the buffer solution includes phosphate buffer, citrate buffer, carbonate buffer, acetate buffer, tris buffer, etc. The organic solvent comprises one or more of methanol, toluene, ethanol, diethyl ether, and ethylene, and those skilled in the art will appreciate that solvents that dissolve the feedstock of the present invention are within the scope of protection.

In the biomedical tissue adhesive provided by the application, the concentration of polyvinyl alcohol in a prepolymer solution is 3% -15% (w/w); preferably 3% -5% (w/w), 5% -6% (w/w), 6% -10% (w/w), or 10% -15% (w/w) etc.

In the biomedical tissue adhesive provided by the application, the alcoholysis degree of the polyvinyl alcohol is more than 75%; preferably 75 to 80% (w/w), 80 to 85% (w/w), 85 to 95% (w/w), or more than 95%, etc. The alcoholysis degree refers to the percentage of hydroxyl groups in the original groups in the product obtained after alcoholysis.

In the biomedical tissue adhesive provided by the application, the concentration of acrylic acid in the prepolymer solution is 15% -30% (w/w); preferably, it is 15% -18% (w/w), 18% -25% (w/w), 25% -30% (w/w), etc. Compared with high molecular polyacrylic acid, the acrylic acid monomer is used, the reaction quality is stable, the succinimide is easier to graft, and because the acrylic acid has certain toxicity, the monomer which does not participate in the reaction needs to be eluted in the subsequent treatment process, and the acrylic acid has good solubility and is easy to elute, so that the overall toxicity risk of the product is reduced.

In the biomedical tissue adhesive provided by the application, the concentration of the N-hydroxysuccinimide acrylate in the prepolymer solution is 0.1% -1% (w/w); preferably, it is 0.1 to 0.2% (w/w), 0.2 to 0.5% (w/w), 0.5 to 1% (w/w), or 1 to 2% (w/w), etc.

Acrylic acid and polyvinyl alcohol are molecular skeletons, and a three-dimensional porous gel topological network structure is constructed, so that the material can quickly absorb liquid on the surface of a moist tissue, and initial weak connection is formed through hydroxyl on the surface of the material and hydroxyl on the surface of the tissue. The N-hydroxysuccinimide acrylate can carry out N-hydroxysuccinimide surface grafting modification on hydroxyl groups of acrylic acid and polyvinyl alcohol, and a first strong bonding site which generates covalent reaction with amino groups on the surface of the tissue is constructed, so that the tissue adhesive has stronger bonding strength.

In the biomedical tissue adhesive provided by the application, the polyhydric phenol compound is selected from one or a combination of more of tannic acid, catechol derivatives, pyrogallol derivatives, dopamine derivatives, caffeic acid derivatives, gallic acid derivatives, catechin and catechin derivatives. The concentration of the polyhydric phenol compound solution is 0.5% -8% (w/w); preferably, it is 0.5 to 1% (w/w), 1 to 1.5% (w/w), or 1.5 to 5% (w/w), 5 to 8% (w/w), etc. The polyphenol compound has wide application in biological fields because of its physiological functions of resisting oxidation, protecting blood vessels, preventing tumors, etc. The collar benzenediol such as dopamine and dopamine derivatives are important components in the adhesive proteins secreted by marine mussel organisms, and the components can be effectively bonded with various surfaces for a long time through the actions of hydrogen bonds, ionic bonds, pi-pi accumulation and the like. Furthermore, poor adhesive performance and excessive swelling behavior of conventional tissue adhesives in wet in vivo environments have been major impediments to numerous applications and functional studies.

In one embodiment of the present application, the polyphenol compound is tannic acid. Tannic acid is a naturally occurring antioxidant polyphenol and has the characteristics of low cytotoxicity, antioxidant activity, antibacterial activity and the like. And tannic acid can be oxidized into o-quinone under alkaline environment, and non-covalent bond can be formed between the tannic acid and the polymer skeleton through hydrogen bond, so that the overall mechanical strength is enhanced.

The polyhydric phenol groups are introduced into a network structure constructed by taking acrylic acid and polyvinyl alcohol as molecular skeletons to form a multiple hydrogen bond to stabilize a tissue adhesion gel topological network structure and improve the biomechanical strength of the material, and meanwhile, the introduced polyhydric phenol groups can react with amino groups and sulfhydryl groups on the surface of the tissue to generate Schiff base reaction and Michael addition reaction to form a second strong bonding site, so that the tissue bonding strength is further improved. Schiff base reaction means that carbonyl groups in the polyphenol groups can react with amino groups to generate organic compounds containing imine or azomethine characteristic groups, and Michael addition reaction means that carbanion carries out conjugated addition reaction on alpha, beta-unsaturated aldehydes, ketones, carboxylic acids, esters, nitriles, nitro compounds and the like, namely, the polyphenol groups react with mercapto groups.

In the biomedical tissue adhesives provided herein, the prepolymer further comprises a crosslinking agent and/or a photoinitiator.

In the biomedical tissue adhesives provided herein, the cross-linking agent comprises one or more of methacrylic anhydride gelatin (GelMA), polyethylene glycol diacrylate (PEGDA), N' -Methylenebisacrylamide (MBAA). In the prepolymer solution, the concentration of the cross-linking agent is 0.01% -0.1% (w/w); preferably, it is 0.01 to 0.05% (w/w), 0.05 to 0.08% (w/w), or 0.08 to 0.1% (w/w), etc.

In the biomedical tissue adhesives provided herein, the photoinitiator includes alpha-ketoglutarate and/or Irgacure 2959. In the prepolymer solution, the concentration of the photoinitiator is 0.05% -0.5% (w/w); preferably, it is 0.05 to 0.1% (w/w), 0.1 to 0.2% (w/w), or 0.2 to 0.5% (w/w), etc. The photoinitiator is also called a photosensitizer or a photo-curing agent, and is a compound capable of absorbing energy with a certain wavelength in an ultraviolet light region (250-420 nm) or a visible light region (400-800 nm) to generate free radicals, cations and the like so as to initiate polymerization, crosslinking and curing of monomers.

In the biomedical tissue adhesive provided by the application, the raw materials of the prepolymer comprise polyvinyl alcohol, acrylic acid, N-hydroxysuccinimide acrylate, a cross-linking agent and a photoinitiator, the prepolymer is a substance generated by the reaction of the 5 raw materials, the prepolymer needs to be subjected to photo-crosslinking to form hydrogel, and the hydrogel is soaked in a polyphenol compound solution to react again to generate the biomedical tissue adhesive.

The biomedical tissue adhesive provided by the invention has the following action mechanism: the biomedical tissue adhesive is in a dry state, can be directly adhered to the wet and moist tissue surface without special treatment before use, and a double-network structure formed by acrylic acid and polyvinyl alcohol in the adhesive can be used as a water-absorbing and water-retaining medium. The hydroxyl and acrylic acid grafted N-succinimidyl acrylate in the tissue adhesive can form covalent and non-covalent bonds with the tissue surface, and has high adhesive strength. The polyhydric phenol groups are introduced into the network structure, and the tissue bonding strength is further improved through the formation of multiple hydrogen bonds.

In the biomedical tissue adhesive provided by the application, the surface of the tissue adhesive is provided with a uniform micropore array. The depth of each micropore in the micropore array is 50% -100% of the thickness of the adhesive film layer. In one embodiment of the present application, when the thickness of the adhesive film layer is 200 μm, the depth of each micropore is 100 μm to 200 μm; preferably, the method comprises the steps of, 100 to 120 μm, 120 to 150 μm, 150 to 200 μm, etc. The depth of each of the micro-holes may be consistent with the thickness of the tissue adhesive, in which case each of the micro-holes may penetrate the tissue adhesive. The micropore spacing of the adhesive film layer between the micropore arrays is 10-100 mu m; preferably 10 to 50 μm, 50 to 80 μm, or 80 to 100 μm. The micropore spacing can enable the surface of the adhesive film layer to form a uniform micropore array regularly. Due to the existence of the micropore array, the surface roughness and the specific surface area of the tissue adhesive are improved, the tissue adhesive is easier to attach to tissues, and the adhesion, migration and differentiation of cells are positively influenced. The aperture of each micropore of the micropore array is 10-1000 mu m; preferably 10 to 100 μm, 100 to 500 μm, 500 to 1000 μm, etc. The shape of each microwell cross section of the microwell array of the tissue adhesive is various, and can be triangular, rectangular, elliptical, etc. The various micropore structures can adapt to complex tissue surfaces. Although high surface tension on small dimensions tends to collapse and retract the micropores, the tissue adhesive uses its dissipative matrix to keep the structure stably present, and the microporous structure is beneficial for enhancing tissue adhesion properties. When the tissue adhesive is adhered to tissues, water and air in the micropores can be discharged in a pressing mode and the like, so that pressure difference between the inside and the outside of the micropores is caused, additional suction force is generated, relative sliding between the tissue adhesive and the surface of the tissues in the initial adhesion stage is reduced, and the adhesion performance of the tissue adhesive is improved.

A second aspect of the present application provides a method of preparing a biomedical tissue adhesive comprising the steps of:

1) Proportioning polyvinyl alcohol, acrylic acid, N-hydroxysuccinimide acrylate, a cross-linking agent and a photoinitiator in the biomedical tissue adhesive according to the proportion relation of the first aspect, and stirring and mixing to obtain a prepolymer solution;

3) Soaking the hydrogel of the step 2) in a polyhydric phenol compound solution in the biomedical tissue adhesive to obtain an adhesive precursor;

In the preparation method provided by the application, step 1) is to mix the polyvinyl alcohol, the acrylic acid, the N-hydroxysuccinimide acrylate, the cross-linking agent and the photoinitiator in the biomedical tissue adhesive according to the proportion relation of the first aspect, and stir and mix the mixture to obtain a prepolymer solution. The prepolymer solution comprises the following components in percentage by mass: 15-30% (w/w) of acrylic acid, 3-15% (w/w) of polyvinyl alcohol, 0.1-2% (w/w) of N-succinimidyl acrylate, 0.1-1% (w/w) of cross-linking agent, 0.05-0.5% (w/w) of photoinitiator, and the balance of water, aqueous solution or organic solvent to form a polyphenol compound solution or prepolymer solution. The aqueous solution includes physiological solution including physiological saline, wilt's solution, le Shi solution, and tai's solution, and buffer solution including phosphate buffer, citrate buffer, carbonate buffer, acetate buffer, tris buffer, and the like. The organic solvent comprises one or more of methanol, toluene, ethanol, diethyl ether, and ethylene, and those skilled in the art will appreciate that solvents that dissolve the feedstock of the present invention are within the scope of protection. Wherein the stirring time is 4-12 h; preferably, the time is 4 to 8 hours, 8 to 10 hours, 10 to 12 hours, or the like. In one embodiment of the present application, deionized water may be used as the solution during the stirring process. In the process, acrylic acid and polyvinyl alcohol react to form a molecular skeleton, a three-dimensional porous gel topological network structure is constructed, N-hydroxysuccinimide acrylate carries out N-hydroxysuccinimide surface grafting modification on hydroxyl groups of the acrylic acid and the polyvinyl alcohol, and a first strong binding site which generates covalent reaction with amino groups on the surface of a tissue is constructed. The crosslinking agent may crosslink the aforementioned compounds. The photoinitiator may initiate curing of the aforementioned compounds under conditions such as ultraviolet light.

In the preparation method provided by the application, the step 2) is to carry out photocrosslinking on the prepolymer solution in the step 1) to obtain the hydrogel. Wherein the reaction time of photocrosslinking is 5-20 min; preferably, it is 5 to 10 minutes, 10 to 15 minutes, 15 to 20 minutes, or the like. Photocrosslinking is a reaction in which a compound is photolyzed after being irradiated with light, or when a part of bonds are separated, activated molecules such as generated radicals are bonded to each other to cause a polymer chain to form a network structure. The photoinitiator can absorb energy with a certain wavelength in ultraviolet light (250-420 nm) to generate free radicals, cations and the like, so that crosslinking and curing of polyvinyl alcohol, acrylic acid and N-hydroxysuccinimide acrylate are initiated. In one embodiment of the present application, photocrosslinking is carried out under an ultraviolet lamp.

In the preparation method provided by the application, the step 3) is to soak the hydrogel in the step 2) in the polyphenol compound solution in the biomedical tissue adhesive to obtain the adhesive precursor. Wherein soaking means that the hydrogel is completely immersed in the solution of the polyphenol compound. The concentration of the polyhydric phenol compound solution is 0.5% -8% (w/w); preferably, it is 0.5 to 1% (w/w), 1 to 1.5% (w/w), or 1.5 to 5% (w/w), 5 to 8% (w/w), etc. The solvent of the polyphenol compound solution is selected from water, an aqueous solution, or a solution of a polyphenol compound or a prepolymer formed in an organic solvent. The aqueous solution includes physiological solution including physiological saline, wilt's solution, le Shi solution, and tai's solution, and buffer solution including phosphate buffer, citrate buffer, carbonate buffer, acetate buffer, tris buffer, and the like. The organic solvent comprises one or more of methanol, toluene, ethanol, diethyl ether and cyclohexane. Wherein, the soaking treatment is carried out in the dark, and the reaction time is 12-48 h; preferably, the time is 12 to 24 hours, 24 to 36 hours, 36 to 48 hours, or the like. The polyphenol compound is added in the step to introduce a polyphenol group into the crosslinked network structure in the step 2) to form multiple hydrogen bonds, stabilize the tissue adhesion gel topological network structure and improve the biomechanical strength of the material, and form a second strong bonding site, so that the tissue bonding strength is further improved.

In the preparation method provided by the application, the step 4) is to dry the adhesive precursor of the step 3) to obtain the biomedical tissue adhesive. Wherein the drying may be freeze drying and/or vacuum drying.

In a third aspect the present application provides the use of the biomedical tissue adhesive described above or the preparation method described above for the preparation of a medical adhesive material.

The present application is further illustrated by the following examples, which are not intended to limit the scope of the present application. All reagents were commercially available as analytically pure products.

Implementation of the embodiments example 1

A prepolymer solution was prepared, which contained a deionized water solution of polyvinyl alcohol having a concentration of 15% (w/w) and an alcoholysis degree of 75%, 20% (w/w) acrylic acid, 0.1% (w/w) N, N' -methylenebisacrylamide, 0.05% (w/w) alpha-ketoglutaric acid, and 0.5% (w/w) N-hydroxysuccinimide acrylate, and was sufficiently and uniformly stirred to obtain a prepolymer solution.

The prepolymer solution was poured into a mold having a thickness of 500 μm and crosslinked under an ultraviolet lamp for 20min to form a hydrogel. Immersing in 1.0% (w/w) tannic acid solution under the condition of avoiding light, immersing for 24 hours, and taking out to obtain the tissue adhesive precursor. And carrying out in-situ freeze-drying on the tissue adhesive precursor to obtain the tissue adhesive.

Comparative example 1

Preparing a prepolymer solution, wherein the prepolymer solution contains a deionized water solution of 15% (w/w) of polyvinyl alcohol with alcoholysis degree of 75%, 20% (w/w) of acrylic acid, 0.1% (w/w) of N, N' -methylene bisacrylamide, 0.05% (w/w) of alpha-ketoglutaric acid and 0.5% (w/w) of N-hydroxysuccinimide acrylate, and fully and uniformly stirring the solution to obtain the prepolymer solution.

The prepolymer solution was poured into a mold having a thickness of 500 μm and crosslinked under an ultraviolet lamp for 20min to form a hydrogel. And freeze-drying the hydrogel in situ to obtain the tissue adhesive.

Example 2

Preparing a prepolymer solution, wherein the prepolymer solution comprises 8% (w/w) of polyvinyl alcohol with alcoholysis degree of 85%, 30% (w/w) of acrylic acid, 0.1% (w/w) of N, N' -methylene bisacrylamide, 0.05% (w/w) of alpha-ketoglutaric acid and 1% (w/w) of N-hydroxysuccinimide acrylate in deionized water, and fully and uniformly stirring the solution to obtain the prepolymer solution.

The prepolymer solution was poured into a mold having a thickness of 500 μm and crosslinked under an ultraviolet lamp for 20min to form a hydrogel. Immersing in 1% (w/w) tannic acid solution under the condition of avoiding light for 24 hours, and taking out to obtain the tissue adhesive precursor. And carrying out in-situ freeze-drying on the tissue adhesive precursor to obtain the tissue adhesive.

Example 3

Pouring the prepolymer solution into a mold with the thickness of 500 mu m to prepare micropores with the distance of 80 mu m, the depth of 150 mu m and the aperture of 200 mu m; and cross-linking under ultraviolet lamp for 20min to form hydrogel. Immersing in 1.5% (w/w) catechol solution under dark condition, soaking for 24h, and taking out to obtain the tissue adhesive precursor. And carrying out in-situ freeze-drying on the tissue adhesive precursor to obtain the tissue adhesive.

Example 4

Preparing a prepolymer solution, wherein the prepolymer solution comprises 10% (w/w) of polyvinyl alcohol with alcoholysis degree of 75%, 25% (w/w) of acrylic acid, 0.1% (w/w) of polyethylene glycol diacrylate, 0.05% (w/w) of alpha-ketoglutaric acid and 1% (w/w) of N-hydroxysuccinimide acrylate in deionized water, and fully and uniformly stirring the solution to obtain the prepolymer solution.

The prepolymer solution was poured into a mold having a thickness of 500 μm and crosslinked under an ultraviolet lamp for 20min to form a hydrogel. Immersing in 0.5% (w/w) tannic acid solution under dark condition, soaking for 48 hr, and taking out to obtain the tissue adhesive precursor. And carrying out in-situ freeze-drying on the tissue adhesive precursor to obtain the tissue adhesive.

Comparative example 2

Preparing a prepolymer solution, wherein the prepolymer solution comprises deionized water solution of 1% (w/w) polyvinyl alcohol with alcoholysis degree of 75%, 25% (w/w) acrylic acid, 0.1% (w/w) polyethylene glycol diacrylate, 0.05% (w/w) alpha-ketoglutaric acid and 1% (w/w) N-hydroxysuccinimide acrylate, and fully and uniformly stirring the deionized water solution to obtain the prepolymer solution.

Comparative example 3

Preparing a prepolymer solution, wherein the prepolymer solution comprises 10% (w/w) of polyvinyl alcohol with alcoholysis degree of 75%, 10% (w/w) of acrylic acid, 0.1% (w/w) of polyethylene glycol diacrylate, 0.05% (w/w) of alpha-ketoglutaric acid and 1% (w/w) of N-hydroxysuccinimide acrylate in deionized water, and fully and uniformly stirring the solution to obtain the prepolymer solution.

The ingredients of the above examples and comparative examples are shown in Table 1:

TABLE 1 Components of biomedical tissue adhesives

The properties of the tissue adhesives prepared in the examples of the present invention were measured separately:

(1) Scanning electron microscope test

The results of the test are shown in FIG. 1, suggesting that tannic acid treatment may help the binder form a loose structure to facilitate water absorption and adhesion reactions.

(2) Fourier infrared spectroscopy

As a result of detection, as shown in FIG. 2, the adhesive prepared in example 1 was used at 1608cm ^–1 1535cm ^–1 A distinct c=c characteristic peak appears, indicating successful introduction of the polyphenol group, suggesting the formation of a second strong binding site.

(3) Swelling ratio test the tissue adhesives of the above examples and comparative examples were taken, the measured thickness was designated as V0, immersed in PBS solution, taken out at 1, 2, 4, 7 days, the surface water was scraped off with filter paper, and the colloid thickness was measured and designated as Vs (s=1, 2, 4, 7). The swelling ratio q= (Vs-V0)/V0, and the result is shown in table 3.

TABLE 3 swelling ratio data

	D1	D2	D4	D7
					Example 1	21％	25％	25％	25％
Comparative example 1	185％	205％	205％	205％
					Example 2	12％	18％	18％	20％
Example 3	26％	31％	31％	31％
					Example 4	18％	20％	20％	20％
Comparative example 2	1000％	1200％	1200％	1250％
					Comparative example 3	85％％	92％	92％	92％

(4) Evaluation of adhesion Strength

The above examples and comparative examples were taken separately and were referred to YY/T0729.1 tissue adhesive bonding performance test method part 1: lap-shear tensile load strength adhesion strength testing was performed. After washing the pigskin, it was immersed in PBS. The adhesive was applied to the wet pigskin and pressed with a 200g weight for 10min. And shear testing was performed using a tensile machine. The test results are shown in Table 3.

TABLE 3 adhesion Strength data

	Adhesive strength (KPa)
		Example 1	102.7
Comparative example 1	56.4
		Example 2	105.7
Example 3	117.3
		Example 4	94.6
Comparative example 2	46.3
		Comparative example 3	18.5

The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims

1. A biomedical tissue adhesive, wherein the biomedical tissue adhesive comprises a prepolymer and a polyphenol compound, and the prepolymer comprises one or more of polyvinyl alcohol, acrylic acid and N-hydroxysuccinimide acrylate.

2. The biomedical tissue adhesive according to claim 1, wherein in the solution of the prepolymer, the concentration of the polyvinyl alcohol is 3% -15% (w/w), and the alcoholysis degree of the polyvinyl alcohol is 75% or more;

and/or, in the solution of the prepolymer, the concentration of the acrylic acid is 15% -30% (w/w);

and/or, the concentration of the N-hydroxysuccinimide acrylate in the solution of the prepolymer is 0.1% to 2% (w/w).

3. The biomedical tissue adhesive according to claim 1, wherein the polyhydric phenol compound is selected from one or more of tannic acid, catechol derivatives, pyrogallol derivatives, dopamine derivatives, caffeic acid derivatives, gallic acid derivatives, catechins, catechin derivatives.

4. The biomedical tissue adhesive according to claim 1, wherein said polyhydric phenol compound has a solution concentration of 0.5% to 8% (w/w).

5. The biomedical tissue adhesive according to claim 1, wherein said prepolymer further comprises a cross-linking agent and/or a photoinitiator.

6. The biomedical tissue adhesive according to claim 5, wherein said cross-linking agent comprises a combination of one or more of a group consisting of a class a acrylated gelatin, a polyethylene glycol diacrylate, N' -methylenebisacrylamide;

and/or the photoinitiator comprises alpha-ketoglutaric acid and/or Irgacure 2959.

7. The biomedical tissue adhesive according to claim 5, wherein the concentration of said crosslinking agent in the solution of the prepolymer is 0.01% to 0.1% (w/w); and/or, the concentration of the photoinitiator in the prepolymer solution is 0.05% -0.5% (w/w).

8. The method of preparing a biomedical tissue adhesive according to any one of claims 1 to 7, comprising the steps of:

1) Stirring and mixing the polyvinyl alcohol, the acrylic acid N-hydroxysuccinimide ester, the cross-linking agent and the photoinitiator to obtain a prepolymer solution;

9. The method of manufacturing of claim 8, further comprising one or more of the following features:

a) In the step 1), the stirring time is 4-12 h;

b) In the step 2), the reaction time of the photo-crosslinking is 5-20 min;

c) In the step 3), the soaking treatment is carried out in a dark place, and the soaking treatment time is 12-48 hours;

d) In step 4), the drying is freeze drying and/or vacuum drying.

10. Use of a biomedical tissue adhesive according to any one of claims 1 to 7 or a method of preparation according to any one of claims 8 to 9 for the preparation of a medical adhesive material.