Environment-friendly degradable biological adhesive and preparation method thereof

Abstract

The invention discloses an environment-friendly degradable biological adhesive and a preparation method thereof, and belongs to the technical field of macromolecular adhesive preparation. The preparation method comprises the following steps: reacting a pre-activated gallic acid mixed solution, a pre-activated oxidized hyaluronic acid mixed solution and a diamine cross-linking agent at 20-25 DEG C for 15-20 hours, and performing dialysis treatment to obtain a gallic acid-oxidized hyaluronic acid mixed solution; the gallic acid-oxidized hyaluronic acid mixed solution and the glycosaminoglycan dispersion solution are mixed, stirred and left to stand, and the biological adhesive is obtained. Firstly, gallic acid and oxidized hyaluronic acid are mixed and react through a diamine cross-linking agent to obtain a gallic acid-oxidized hyaluronic acid mixed solution, then the gallic acid-oxidized hyaluronic acid mixed solution and a glycosaminoglycan dispersion solution are mixed and cross-linked to form the biological adhesive, and the biological adhesive has good adhesion performance, antibacterial performance and air permeability.

Description

Technical Field

[0001] The present invention belongs to the technical field of macromolecular adhesive preparation, and particularly relates to an environmentally friendly and biodegradable bioadhesive and a preparation method thereof. Background Art

[0002] As a kind of soft and wet material with a three-dimensional network structure, hydrogels show irreplaceable application value in the biomedical field due to their unique physical and chemical properties. The porous structure and high water content characteristics highly similar to the natural extracellular matrix (ECM) not only endow it with excellent biocompatibility, but also support key biological processes such as cell adhesion and nutrient transport. Hydrogels are mainly composed of hydrophilic polymer materials. Hydrogels formed by hydrophilic polymer materials usually have a porous structure and a relatively high water content, allowing gas and liquid to permeate. With the continuous in-depth research on hydrogels, various functional hydrogels have been successively reported, such as stimulus-responsive hydrogels, self-healing hydrogels, adhesive hydrogels, antibacterial hydrogels, etc. These hydrogels combine with the surface of the matrix material through physical or chemical interactions at the interface, so that the hydrogel binds to its surface, that is, the hydrogel can adhere to the surface of the matrix material (such as metals, glass, plastics, porcine skin tissues, etc.) to achieve specific functions. In recent years, through the cross-integration of material chemistry, bioengineering and clinical medicine, the research on hydrogels in bioadhesive materials has advanced from basic function development to a precise and intelligent innovation stage. A bioadhesive is an adhesive material prepared by biotechnology or modification of natural materials, used to replace or supplement traditional chemical adhesives, and has the advantages of biocompatibility, degradability and functionality. According to the raw material sources and preparation methods, it can be divided into the following two categories: (1) Natural bioadhesives. Based on natural polymer materials, such as collagen, chitosan, fibrin, tannin, lignin, etc. For example, collagen adhesives are widely used in skin and soft tissue repair because they are similar to human tissue components. (2) Synthetic bioadhesives. Materials prepared by chemical synthesis or bioengineering, such as polylactic acid (PLA), polyethylene glycol (PEG), polyurethane (PU), etc. However, most of the current hydrogel-based adhesives still have some problems: (1) The preparation method is complex and requires complex molecular structure design; (2) The adhesion strength is not high enough and can only show adhesion to specific materials; (3) The mechanical properties are poor; (4) The air permeability is poor during use and it is easy to be infected, which is not conducive to wound recovery; (5) Lack of antibacterial activity required for materials to be applied to easily infected wounds. Therefore, some new improvement technologies have been adopted in the prior art to solve such technical problems.

[0003] Patent CN116549712A discloses a degradable wound-healing medical adhesive and its preparation method. In this invention, oxidized sodium alginate and modified alginate microspheres loaded with growth factors are mixed in proportion to obtain component A; then, carboxymethyl chitosan and modified polylysine are added to water, and after dissolution, a mixed solution of carboxymethyl chitosan and modified polylysine is obtained. Then, a thickener is dissolved in the mixed solution of carboxymethyl chitosan and modified polylysine to obtain component B; when in use, the two are mixed and extruded to achieve the bonding effect.

[0004] Patent CN116173286A discloses a medical adhesive and its preparation method and application. In this invention, modified sodium alginate, tannic acid, and an inorganic substance capable of generating divalent metal cations are dissolved in water to obtain solution A; a positively charged polymer, a nano-composite antibacterial agent, and glucono delta-lactone are dissolved in water to obtain solution B. After mixing solution A and solution B evenly, a medical adhesive is obtained, achieving good adhesion, mechanical properties, antibacterial properties, and other performances.

[0005] The above improvements mainly utilize natural polymer materials such as sodium alginate and carboxymethyl chitosan. By mixing with other added materials, the improvement of the bonding effect is achieved. Although natural polymer materials such as sodium alginate and carboxymethyl chitosan are non-toxic to the human body, have good in vitro degradation performance, and are environmentally friendly, their adhesiveness is often low when used at low concentrations, and the concentration needs to be increased to have good adhesion performance. Although increasing the concentration has a good effect on improving the adhesion performance, too high a concentration will not only cause the adhesive to solidify but sometimes often cause excessive cross-linking, resulting in poor air permeability. And poor air permeability makes the wound prone to bacterial infection, which has a greater negative impact on the wound recovery.

[0006] Therefore, it is of great significance to use natural polymer materials to prepare adhesives with good adhesion performance while improving air permeability. Summary of the Invention

[0007] According to the deficiencies of the prior art, in the present invention, gallic acid and oxidized hyaluronic acid are first mixed and reacted through a diamine cross-linking agent to obtain a gallic acid-oxidized hyaluronic acid mixed solution, and then cross-linked with an amino polysaccharide dispersion liquid to form a bioadhesive, thereby solving the technical problems proposed in the background art. Specifically, the technical solution of the present invention includes the following content:

[0008] The second object of the present invention is to provide a preparation method of an environmentally friendly and degradable bioadhesive, and the preparation method includes the following steps:

[0009] After the pre-activated gallic acid mixed solution, the pre-activated oxidized hyaluronic acid mixed solution, and the diamine cross-linking agent react at 20°C to 25°C for 15h to 20h, a gallic acid-oxidized hyaluronic acid mixed solution is obtained through dialysis treatment;

[0010] The gallic acid-oxidized hyaluronic acid mixture and the aminopolysaccharide dispersion are mixed, stirred, and allowed to stand to obtain the bioadhesive.

[0011] Furthermore, the preparation method of the pre-activated gallic acid mixture includes the following steps:

[0012] Gallic acid, dimethyl sulfoxide, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1-hydroxybenzotriazole are mixed and dispersed, and then stirred and activated at 10°C to 15°C for 15 min to 20 min to obtain the pre-activated gallic acid mixture.

[0013] Furthermore, the weight ratio of gallic acid:dimethyl sulfoxide:1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride:1-hydroxybenzotriazole is 1:200 - 300:1 - 1.5:1 - 1.5.

[0014] Furthermore, the preparation method of the pre-activated oxidized hyaluronic acid mixture includes the following steps:

[0015] Hyaluronic acid, deionized water, and sodium periodate are mixed and dispersed, placed in a light-proof environment, and then reacted at 25°C to 30°C for 10 h to 12 h. Subsequently, dialysis and freezing treatments are performed in sequence to obtain oxidized hyaluronic acid;

[0016] The oxidized hyaluronic acid, dimethyl sulfoxide, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1-hydroxybenzotriazole are mixed and dispersed, and then stirred and activated at 10°C to 15°C for 15 min to 20 min to obtain the pre-activated oxidized hyaluronic acid mixture.

[0017] Furthermore, the weight ratio of hyaluronic acid:deionized water:sodium periodate is 1:100 - 150:0.5 - 1.

[0018] Furthermore, the weight ratio of oxidized hyaluronic acid:dimethyl sulfoxide:1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride:1-hydroxybenzotriazole is 1:150 - 200:1 - 1.5:1 - 1.5.

[0019] Furthermore, the diamine crosslinking agent includes 1,4-butanediamine or 1,6-hexanediamine.

[0020] Furthermore, the weight ratio of the pre-activated gallic acid mixture:the pre-activated oxidized hyaluronic acid mixture:the diamine crosslinking agent is 1:5 - 7:0.01 - 0.02.

[0021] Furthermore, the aminopolysaccharide dispersion is prepared by mixing and dispersing chitosan and absolute ethanol according to a weight ratio of 1:100 - 120.

[0022] Further, the weight ratio of the gallic acid-oxidized hyaluronic acid mixture to the polysaccharide amine dispersion is 1:1 to 3.

[0023] The second object of the present invention is to provide a bioadhesive prepared by a preparation method of an environmentally friendly and biodegradable bioadhesive.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] The present invention utilizes the principle of molecular bionics to mimic the adhesiveness of mussel adhesive protein. Mussel adhesive protein has good adhesion performance due to the oxidative self-polymerization cross-linking between the polyphenolic hydroxyl groups and amino groups on the dopa structure. Using gallic acid with a polyphenolic hydroxyl structure as one of the raw materials, first, natural polymer material hyaluronic acid with a carboxyl structure is oxidized to a certain extent to break the adjacent dihydroxy groups in its structure to generate aldehyde groups, thereby obtaining oxidized hyaluronic acid. Then, after pre-activating the carboxyl groups on gallic acid and oxidized hyaluronic acid respectively, they are mixed and stirred with a diamine cross-linking agent to undergo amidation condensation to obtain a gallic acid-oxidized hyaluronic acid mixture. The gallic acid-oxidized hyaluronic acid mixture and the polysaccharide amine dispersion are mixed and cross-linked to form a bioadhesive. The role of the diamine cross-linking agent is not only to enable gallic acid to be chemically condensed onto oxidized hyaluronic acid, but also the diamine cross-linking agent with a longer carbon chain can improve the flexibility of the molecular chain, reduce the resistance of chain segment movement, expand the molecular pores and increase the gap between chain segments, thereby enhancing the air permeability. If hyaluronic acid is over-oxidized, it will lead to too many aldehyde functional groups produced by oxidation. When the gallic acid-oxidized hyaluronic acid mixture and the polysaccharide amine dispersion are mixed and cross-linked, it will cause too many aldehyde groups to bind to the amino groups on the polysaccharide amine, and then the oxidative polymerization cross-linking between the phenolic hydroxyl groups and amino groups on the prepared bioadhesive will be poor, and the adhesion performance of the bioadhesive will deteriorate. The synergistic cooperation of gallic acid and chitosan improves the antibacterial performance of the bioadhesive while ensuring good adhesion performance through the construction of oxidative self-polymerization cross-linking between polyphenolic hydroxyl groups and amino groups. Specific embodiments

[0026] The technical solutions of the present invention will be clearly and completely described below through the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0027] Unless otherwise specified, the raw materials and reagents used in the present invention below are all commercially available products or can be prepared by known methods.

[0028] Preparation Example 1:

[0029] Preparation method of pre-activated gallic acid mixture, specifically including the following process:

[0030] Weigh 400 g of dimethyl sulfoxide and place it in a flask, and then place it in a temperature environment of 10 °C. At this time, weigh 2 g of gallic acid, 2 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 2 g of 1-hydroxybenzotriazole and add them to dimethyl sulfoxide together, and control the temperature environment at 10 °C, and stir and activate at a stirring speed of 100 r / min for 15 min to obtain a pre-activated gallic acid mixture.

[0031] Preparation Example 2:

[0032] Preparation method of pre-activated gallic acid mixture, specifically including the following process:

[0033] Weigh 500 g of dimethyl sulfoxide and place it in a flask, and then place it in a temperature environment of 10 °C. At this time, weigh 2 g of gallic acid, 3 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 2.5 g of 1-hydroxybenzotriazole and add them to dimethyl sulfoxide together, and control the temperature environment at 10 °C, and stir and activate at a stirring speed of 100 r / min for 20 min to obtain a pre-activated gallic acid mixture.

[0034] Preparation Example 3:

[0035] Preparation method of pre-activated gallic acid mixture, specifically including the following process:

[0036] Weigh 600 g of dimethyl sulfoxide and place it in a flask, and then place it in a temperature environment of 15 °C. At this time, weigh 2 g of gallic acid, 3 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 3 g of 1-hydroxybenzotriazole and add them to dimethyl sulfoxide together, and control the temperature environment at 15 °C, and stir and activate at a stirring speed of 100 r / min for 20 min to obtain a pre-activated gallic acid mixture.

[0037] Preparation Example 4:

[0038] Preparation method of pre-activated oxidized hyaluronic acid mixture, specifically including the following process:

[0039] Weigh 5 g of hyaluronic acid powder and add it to 500 g of deionized water. Stir continuously at a speed of 400 r / min until a homogeneous and transparent solution is formed (during this period, appropriate heating can be used to promote the dissolution and dispersion of hyaluronic acid, but it needs to be cooled to room temperature before adding sodium periodate). Subsequently, add 2.5 g of sodium periodate, mix and stir, and immediately place it in a dark environment. Then control the reaction temperature at 25 °C and carry out the reaction in the dark for 10 h. As soon as the reaction time is up, immediately add 10 g of ethylene glycol and continue to stir and react for 2 h to fully quench sodium periodate. Mix the finally obtained reaction solution with an equal volume of absolute ethanol and stir until it becomes turbid. Then place it in a dialysis bag with a cut-off molecular weight of 3.5 kDa and dialyze with deionized water for 2 days. Finally, use a freeze dryer to freeze-dry the dialyzed product solution to obtain oxidized hyaluronic acid. The aldehyde group concentration of the oxidized hyaluronic acid measured by the "hydroxylamine hydrochloride-potentiometric titration method" is 2.17 mmol / g;

[0040] Weigh 300 g of dimethyl sulfoxide and place it in a flask, and then place it in a temperature environment of 10 °C. At this time, weigh 2 g of oxidized hyaluronic acid and add it to dimethyl sulfoxide, and disperse it by ultrasonic treatment at an ultrasonic power of 300 W for 10 min. After the ultrasonic treatment is completed, add 2 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 2 g of 1-hydroxybenzotriazole, and control it in a temperature environment of 10 °C. Stir and activate at a stirring speed of 100 r / min for 15 min to obtain a pre-activated oxidized hyaluronic acid mixture.

[0041] Preparation Example 5:

[0042] The preparation method of the pre-activated oxidized hyaluronic acid mixture specifically includes the following process:

[0043] Weigh 5 g of hyaluronic acid powder and add it to 700 g of deionized water. Stir continuously at a speed of 400 r / min until a homogeneous and transparent solution is formed (during this period, appropriate heating can be used to promote the dissolution and dispersion of hyaluronic acid, but it needs to be cooled to room temperature before adding sodium periodate). Subsequently, add 4 g of sodium periodate, mix and stir, and immediately place it in a dark environment. Then control the reaction temperature at 25 °C and carry out the reaction in the dark for 11 h. As soon as the reaction time is up, immediately add 10 g of ethylene glycol and continue to stir and react for 2 h to fully quench sodium periodate. Mix the finally obtained reaction solution with an equal volume of absolute ethanol and stir until it becomes turbid. Then place it in a dialysis bag with a cut-off molecular weight of 3.5 kDa and dialyze with deionized water for 2 days. Finally, use a freeze dryer to freeze-dry the dialyzed product solution to obtain oxidized hyaluronic acid. The aldehyde group concentration of the oxidized hyaluronic acid measured by the "hydroxylamine hydrochloride-potentiometric titration method" is 2.32 mmol / g;

[0044] Weigh 350 g of dimethyl sulfoxide and place it in a flask, then place it in a temperature environment of 10°C. At this time, weigh 2 g of oxidized hyaluronic acid and add it to the dimethyl sulfoxide, and disperse it by ultrasonic treatment at a power of 300 W for 10 min. After the ultrasonic treatment, add 3 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 2 g of 1-hydroxybenzotriazole, and control the temperature environment at 10°C, and stir and activate at a stirring speed of 100 r / min for 20 min to obtain a pre-activated oxidized hyaluronic acid mixture.

[0045] Preparation Example 6:

[0046] A method for preparing a pre-activated oxidized hyaluronic acid mixture specifically includes the following process:

[0047] Weigh 5 g of hyaluronic acid powder and add it to 750 g of deionized water, and continuously stir at a speed of 400 r / min until a uniform and transparent solution is formed (during this period, appropriate heating can be used to promote the dissolution and dispersion of hyaluronic acid, but it needs to be cooled to room temperature before adding sodium periodate). Then add 5 g of sodium periodate, mix and stir, and immediately place it in a dark environment, and then control the reaction temperature at 30°C, and carry out the reaction in the dark at this temperature for 12 h. As soon as the reaction time arrives, immediately add 10 g of ethylene glycol and continuously stir and react for 2 h to fully quench sodium periodate. Mix the finally obtained reaction solution with an equal volume of absolute ethanol and stir until it becomes turbid, then place it in a dialysis bag with a cut-off molecular weight of 3.5 kDa, dialyze with deionized water for 2 days, and finally use a freeze dryer to freeze-dry the dialyzed product solution to obtain oxidized hyaluronic acid. The aldehyde group concentration of the oxidized hyaluronic acid measured by the "hydroxylamine hydrochloride-potentiometric titration method" is 2.38 mmol / g;

[0048] Weigh 400 g of dimethyl sulfoxide and place it in a flask, then place it in a temperature environment of 15°C. At this time, weigh 2 g of oxidized hyaluronic acid and add it to the dimethyl sulfoxide, and disperse it by ultrasonic treatment at a power of 300 W for 10 min. After the ultrasonic treatment, add 3 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 3 g of 1-hydroxybenzotriazole, and control the temperature environment at 15°C, and stir and activate at a stirring speed of 100 r / min for 20 min to obtain a pre-activated oxidized hyaluronic acid mixture.

[0049] Preparation Example 7:

[0050] A method for preparing a pre-activated oxidized hyaluronic acid mixture specifically includes the following process:

[0051] Increase the amount of sodium periodate used in Preparation Example 6 to 7 g and increase the light-shielded reaction time to 15 h. The aldehyde group concentration of oxidized hyaluronic acid measured by the "hydroxylamine hydrochloride-potentiometric titration method" is 3.05 mmol / g; the other conditions are the same as those in Preparation Example 6.

[0052] Example 1:

[0053] A preparation method of an environmentally friendly and biodegradable bioadhesive specifically includes the following process:

[0054] Weigh 1 part by weight of the pre-activated gallic acid mixed solution obtained in Preparation Example 1, 5 parts by weight of the pre-activated oxidized hyaluronic acid mixed solution obtained in Preparation Example 4, and 0.01 part by weight of 1,4-butanediamine, mix and stir until evenly dispersed, and then place it in an environment at 20 °C and stir and react at a speed of 200 r / min for 15 h. After the reaction is completed, place the reaction solution in a dialysis bag with a cut-off molecular weight of 3.5 kDa and dialyze with deionized water for 2 days to obtain a gallic acid-oxidized hyaluronic acid mixed solution;

[0055] Weigh 1 part by weight of the gallic acid-oxidized hyaluronic acid mixed solution and 1 part by weight of the chitosan dispersion (mix chitosan and absolute ethanol in a weight ratio of 1:100 and place them in an ultrasonic disperser, and ultrasonically treat them at a power of 400 W for 20 min to obtain the chitosan dispersion) and mix and stir, and then place it in a water bath at 37 °C and let it stand until a glue is formed to complete the preparation of the bioadhesive.

[0056] Example 2:

[0057] A preparation method of an environmentally friendly and biodegradable bioadhesive specifically includes the following process:

[0058] Weigh 1 part by weight of the pre-activated gallic acid mixed solution obtained in Preparation Example 2, 6 parts by weight of the pre-activated oxidized hyaluronic acid mixed solution obtained in Preparation Example 5, and 0.015 part by weight of 1,4-butanediamine, mix and stir until evenly dispersed, and then place it in an environment at 20 °C and stir and react at a speed of 200 r / min for 17 h. After the reaction is completed, place the reaction solution in a dialysis bag with a cut-off molecular weight of 3.5 kDa and dialyze with deionized water for 2 days to obtain a gallic acid-oxidized hyaluronic acid mixed solution;

[0059] Weigh 1 part by weight of the gallic acid-oxidized hyaluronic acid mixed solution and 2 parts by weight of the chitosan dispersion (mix chitosan and absolute ethanol in a weight ratio of 1:110 and place them in an ultrasonic disperser, and ultrasonically treat them at a power of 400 W for 20 min to obtain the chitosan dispersion) and mix and stir, and then place it in a water bath at 37 °C and let it stand until a glue is formed to complete the preparation of the bioadhesive.

[0060] Example 3:

[0061] A preparation method of an environmentally friendly and biodegradable bioadhesive, specifically including the following process:

[0062] Weigh 1 part by weight of the pre-activated gallic acid mixed solution obtained in Preparation Example 3, 7 parts by weight of the pre-activated oxidized hyaluronic acid mixed solution obtained in Preparation Example 6, and 0.02 part by weight of 1,6-hexanediamine, mix and stir until evenly dispersed, and then place it in an environment at 25°C and stir and react at a speed of 200 r / min for 20 h. After the reaction is completed, place the reaction solution in a dialysis bag with a cut-off molecular weight of 3.5 kDa and dialyze with deionized water for 2 days to obtain a gallic acid-oxidized hyaluronic acid mixed solution;

[0063] Weigh 1 part by weight of the gallic acid-oxidized hyaluronic acid mixed solution and 3 parts by weight of the chitosan dispersion (mix chitosan and absolute ethanol in a weight ratio of 1:120 and place it in an ultrasonic disperser, and ultrasonically treat it at a power of 400 W for 20 min to obtain the chitosan dispersion), mix and stir, and then place it in a water bath at 37°C and let it stand until a viscous glue is formed to complete the preparation of the bioadhesive.

[0064] Comparative Example 1:

[0065] A preparation method of an environmentally friendly and biodegradable bioadhesive, specifically including the following process:

[0066] Weigh 1 part by weight of the pre-activated gallic acid mixed solution obtained in Preparation Example 3, 7 parts by weight of the pre-activated oxidized hyaluronic acid mixed solution obtained in Preparation Example 7, and 0.02 part by weight of 1,6-hexanediamine, mix and stir until evenly dispersed, and then place it in an environment at 25°C and stir and react at a speed of 200 r / min for 20 h. After the reaction is completed, place the reaction solution in a dialysis bag with a cut-off molecular weight of 3.5 kDa and dialyze with deionized water for 2 days to obtain a gallic acid-oxidized hyaluronic acid mixed solution;

[0067] Weigh 1 part by weight of the gallic acid-oxidized hyaluronic acid mixed solution and 3 parts by weight of the chitosan dispersion (mix chitosan and absolute ethanol in a weight ratio of 1:120 and place it in an ultrasonic disperser, and ultrasonically treat it at a power of 400 W for 20 min to obtain the chitosan dispersion), mix and stir, and then place it in a water bath at 37°C and let it stand until a viscous glue is formed to complete the preparation of the bioadhesive.

[0068] Comparative Example 2:

[0069] A preparation method of an environmentally friendly and biodegradable bioadhesive, specifically including the following process:

[0070] Weigh 1 part by weight of the pre-activated gallic acid mixture obtained in Preparation Example 3, 7 parts by weight of the pre-activated oxidized hyaluronic acid mixture obtained in Preparation Example 6, and 0.02 part by weight of ethylenediamine, mix and stir until evenly dispersed, and then place it in an environment at 25 °C and stir and react at a speed of 200 r / min for 20 h. After the reaction is completed, place the reaction solution in a dialysis bag with a cut-off molecular weight of 3.5 kDa and dialyze with deionized water for 2 days to obtain a gallic acid-oxidized hyaluronic acid mixture;

[0071] Weigh 1 part by weight of the gallic acid-oxidized hyaluronic acid mixture and 3 parts by weight of the chitosan dispersion (mix chitosan and absolute ethanol in a weight ratio of 1:120 and place it in an ultrasonic disperser, and ultrasonically treat it at a power of 400 W for 20 min to obtain the chitosan dispersion), mix and stir, and then place it in a water bath at 37 °C and let it stand until a viscous glue is formed to complete the preparation of the bioadhesive.

[0072] Comparative Example 3:

[0073] A preparation method of an environmentally friendly and biodegradable bioadhesive specifically includes the following process:

[0074] Weigh 1 part by weight of the pre-activated gallic acid mixture obtained in Preparation Example 3, 7 parts by weight of the pre-activated oxidized hyaluronic acid mixture obtained in Preparation Example 6, and 0.02 part by weight of 1,8-octanediamine, mix and stir until evenly dispersed, and then place it in an environment at 25 °C and stir and react at a speed of 200 r / min for 20 h. After the reaction is completed, place the reaction solution in a dialysis bag with a cut-off molecular weight of 3.5 kDa and dialyze with deionized water for 2 days to obtain a gallic acid-oxidized hyaluronic acid mixture;

[0075] Weigh 1 part by weight of the gallic acid-oxidized hyaluronic acid mixture and 3 parts by weight of the chitosan dispersion (mix chitosan and absolute ethanol in a weight ratio of 1:120 and place it in an ultrasonic disperser, and ultrasonically treat it at a power of 400 W for 20 min to obtain the chitosan dispersion), mix and stir, and then place it in a water bath at 37 °C and let it stand until a viscous glue is formed to complete the preparation of the bioadhesive.

[0076] Comparative Example 4:

[0077] A preparation method of an environmentally friendly and biodegradable bioadhesive specifically includes the following process:

[0078] Weigh 1 part by weight of the pre-activated gallic acid mixed solution obtained in Preparation Example 3, 7 parts by weight of the pre-activated oxidized hyaluronic acid mixed solution obtained in Preparation Example 6, and 0.02 part by weight of 1,8-octanediamine, mix and stir until evenly dispersed, and then place it in an environment at 25 °C and stir and react at a speed of 200 r / min for 20 h. After the reaction is completed, place the reaction solution in a dialysis bag with a cut-off molecular weight of 3.5 kDa and dialyze with deionized water for 2 days to obtain a gallic acid-oxidized hyaluronic acid mixed solution;

[0079] Weigh 1 part by weight of the gallic acid-oxidized hyaluronic acid mixed solution, 3 parts by weight of the sodium alginate dispersion (mix sodium alginate and absolute ethanol in a weight ratio of 1:120 and place it in an ultrasonic disperser, and ultrasonically treat it at a power of 400 W for 20 min to obtain the sodium alginate dispersion), and 0.01 part by weight of the calcium chloride solution (the mass concentration of the calcium chloride solution is 20%), mix and stir, and then place it in a water bath at 37 °C and let it stand until a glue is formed to complete the preparation of the bioadhesive.

[0080] Comparative Example 5:

[0081] A preparation method of an environmentally friendly and biodegradable bioadhesive specifically includes the following process:

[0082] Weigh 1 part by weight of the pre-activated gallic acid mixed solution obtained in Preparation Example 3, 7 parts by weight of the pre-activated oxidized hyaluronic acid mixed solution obtained in Preparation Example 6, and 0.02 part by weight of 1,8-octanediamine, mix and stir until evenly dispersed, and then place it in an environment at 25 °C and stir and react at a speed of 200 r / min for 20 h. After the reaction is completed, place the reaction solution in a dialysis bag with a cut-off molecular weight of 3.5 kDa and dialyze with deionized water for 2 days to obtain a gallic acid-oxidized hyaluronic acid mixed solution;

[0083] Weigh 1 part by weight of the gallic acid-oxidized hyaluronic acid mixed solution and 3 parts by weight of the carboxymethyl chitosan dispersion (mix carboxymethyl chitosan and absolute ethanol in a weight ratio of 1:120 and place it in an ultrasonic disperser, and ultrasonically treat it at a power of 400 W for 20 min to obtain the carboxymethyl chitosan dispersion), mix and stir, and then place it in a water bath at 37 °C and let it stand until a glue is formed to complete the preparation of the bioadhesive.

[0084] (1) Adhesion strength test of the bioadhesive:

[0085] After removing the fat layer of fresh pigskin and leaving the dermis layer, cut it into strips with a length of 5 cm and a width of 2 cm. Then, apply the bioadhesives prepared in Examples 1-3 and Comparative Examples 1-5 to the surface of the pigskin respectively. Then, press another piece of pigskin against it at a pressure of 8 kPa for 30 s to make it completely adhere. Then, in a temperature environment of 25°C ± 2°C, use a universal testing machine to test the adhesion strength at a tensile speed of 10 mm / min. The results are shown in Table 1 below.

[0086] Table 1 Adhesion performance

[0087]

[0088]

[0089] (2) Degradation test:

[0090] Place the bioadhesives prepared in Examples 1-3 and Comparative Examples 1-5 in a constant temperature incubator at 37°C for hermetic curing for 6 h. Then, take them out and immerse them in 10 mL of PBS buffer solution with pH = 7.4 respectively and continue to incubate at 37°C for 6 days. Observe whether there is still solidified bioadhesive in the buffer solution. The results are shown in Table 2 below.

[0091] Table 2 Degradation behavior statistics

[0092]

[0093]

[0094] (3) Antibacterial test:

[0095] Apply the bioadhesives prepared in Examples 1-3 and Comparative Examples 1-5 to the surface of the beef extract peptone agar medium. After curing, evenly apply the Staphylococcus aureus bacterial solution with a bacterial concentration of 1×10 8 to the surface of the beef extract peptone agar medium solidified with the bioadhesive. Then, incubate it upside down in a constant temperature incubator at 37°C for 24 h. Then, take it out and measure the number of bacteria, and calculate the antibacterial rate (using the surface of the beef extract peptone agar medium without adding the bioadhesive as the blank group, and irradiating and sterilizing the blank group under ultraviolet light for 12 h after culturing for 24 h). The results are shown in Table 3 below.

[0096] Table 3 Antibacterial performance

[0097] Material source Bacteriostatic rate (%) Example 1 53.8 Example 2 55.4 Example 3 56.3 Comparative example 1 55.7 Comparative example 2 55.4 Comparative example 3 56.1 Comparative example 4 20.5 Comparative example 5 55.1 Blank group 65.3

[0098] (4) Breathability test:

[0099] According to "ASTM D 737", the air permeability of the bioadhesives prepared in Examples 1 to 3 and Comparative Examples 1 to 5 was tested using a fully automatic air permeability tester. The test area was 20 cm 2 , and the test pressure was 100 Pa. The results are shown in Table 4 below.

[0100] Table 4 Air Permeability

[0101] Material source Air permeability (mm / s) Example 1 3.1 Example 2 3.4 Example 3 3.5 Comparative example 1 3.2 Comparative example 2 1.8 Comparative example 3 1.5 Comparative example 4 3.3 Comparative example 5 3.1 Blank group 3.2

[0102] From the above Tables 1 to 4, the following conclusions can be drawn:

[0103] (1) It can be seen from Examples 1 to 3 that the bioadhesive formed by mixing and reacting gallic acid and oxidized hyaluronic acid through a diamine cross-linking agent to obtain a gallic acid-oxidized hyaluronic acid mixed solution and then mixing and cross-linking with an aminopolysaccharide dispersion has good adhesion performance, antibacterial performance and air permeability.

[0104] (2) It can be found from Comparative Example 1 that the bioadhesive prepared in this system has poor adhesion performance. This may be because the oxidation intensity of hyaluronic acid in this system is too high, and there are more aldehyde functional groups generated by the cleavage of adjacent dihydroxy groups of hyaluronic acid. The aldehyde groups on the prepared oxidized hyaluronic acid consume more amino groups on the chitosan structure, thereby making the oxidative polymerization cross-linking between the phenolic hydroxyl group on gallic acid and the amino group on chitosan poor, resulting in poor adhesion performance of the finally prepared bioadhesive.

[0105] (3) It can be found from Comparative Example 2 that the bioadhesive prepared in this system has poor air permeability performance. This may be because the carbon chain of ethylenediamine is short, and its effect on improving the flexibility of the molecular chain in the bioadhesive is poor. The cross-linking degree under the conditions of this system may be relatively high, resulting in fewer pores in the cross-linked bioadhesive and affecting the air permeability performance.

[0106] (4) It can be found from Comparative Example 3 that the bioadhesive prepared in this system has poor air permeability performance and also poor adhesion performance. This may be because in this system, the carbon chain of 1,8-octanediamine is too long. When the carbon chain is too long, the movement of molecular chain segments may be restricted, resulting in a decrease in air permeability. At the same time, the too long carbon chain may also lead to an increase in rigidity, which instead affects its adhesion performance.

[0107] (5) It can be found from Comparative Example 4 that the bioadhesive prepared in this system has poor antibacterial performance. This may be because in this system, although sodium alginate can cross-link with the gallic acid-oxidized hyaluronic acid mixed solution through hydrogen bond binding and calcium ion chelation, sodium alginate does not have antibacterial properties, and its ability to weaken bacterial infection during wound recovery is poor.

[0108] (6) It can be found from Comparative Example 5 that the bioadhesive prepared by this system shows poor adhesion performance. This may be because although carboxymethyl chitosan has the same amino functional groups as chitosan, carboxymethyl chitosan is a carboxymethylated derivative of chitosan, and a carboxymethyl group is introduced into its structure. On the one hand, this group may replace part of the amino structure in chitosan, resulting in a decrease in the amino content. On the other hand, a steric hindrance effect may occur in the spatial structure, making the cross-linking with the aldehyde groups on gallic acid-oxidized hyaluronic acid poor in the dosage of this system, and the adhesion performance is poor.

[0109] The above-described embodiments have detailed the technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A method for preparing an environmentally friendly and degradable bioadhesive, characterized in that: The preparation method comprises the following steps: The preactivated gallic acid mixed solution, the preactivated oxidized hyaluronic acid mixed solution and the diamine cross-linking agent are reacted at 20° C. to 25° C. for 15 to 20 hours, and then dialyzed to obtain a gallic acid-oxidized hyaluronic acid mixed solution; The gallic acid-oxidized hyaluronic acid mixed solution and the aminopolysaccharide dispersion solution are mixed, stirred, and allowed to stand to obtain the bioadhesive.

2. The method for preparing an environmentally friendly and degradable bioadhesive according to claim 1, characterized in that: The preparation method of the preactivated gallic acid mixed solution comprises the following steps: Gallic acid, dimethyl sulfoxide, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 1-hydroxybenzotriazole are mixed and dispersed, and stirred and activated at 10° C. to 15° C. for 15 min to 20 min to obtain the pre-activated gallic acid mixed solution.

3. The method for preparing an environmentally friendly and degradable bioadhesive according to claim 2, characterized in that: The weight ratio of gallic acid: dimethyl sulfoxide: 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride: 1-hydroxybenzotriazole is 1:200-300:1-1.5:1-1.

5.

4. The method for preparing an environmentally friendly and degradable bioadhesive according to claim 1, characterized in that: The method for preparing the pre-activated oxidized hyaluronic acid mixed solution comprises the following steps: Hyaluronic acid, deionized water and sodium periodate are mixed and dispersed in a light-proof environment, and then reacted at 25°C to 30°C for 10h to 12h, and then dialyzed and frozen to obtain oxidized hyaluronic acid; The oxidized hyaluronic acid, dimethyl sulfoxide, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 1-hydroxybenzotriazole are mixed and dispersed and stirred at 10° C. to 15° C. for 15 min to 20 min to obtain the pre-activated oxidized hyaluronic acid mixed solution.

5. The method for preparing an environmentally friendly and degradable bioadhesive according to claim 4, characterized in that: The weight ratio of the hyaluronic acid: deionized water: sodium periodate is 1:100-150:0.5-1.

6. The method for preparing an environmentally friendly and degradable bioadhesive according to claim 4, characterized in that: The weight ratio of the oxidized hyaluronic acid: dimethyl sulfoxide: 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride: 1-hydroxybenzotriazole is 1:150-200:1-1.5:1-1.

5.

7. The method for preparing an environmentally friendly and degradable bioadhesive according to claim 1, characterized in that: The diamine crosslinking agent includes 1,4-butanediamine or 1,6-hexanediamine.

8. The method for preparing an environmentally friendly and degradable bioadhesive according to claim 1, characterized in that: The weight ratio of the preactivated gallic acid mixed solution: the preactivated oxidized hyaluronic acid mixed solution: the diamine cross-linking agent is 1:5-7:0.01-0.

02.

9. The method for preparing an environmentally friendly and degradable bioadhesive according to claim 1, characterized in that: The weight ratio of the gallic acid-oxidized hyaluronic acid mixed solution to the aminopolysaccharide dispersion is 1:1-3.

10. A bioadhesive prepared by the method for preparing an environmentally friendly and degradable bioadhesive according to any one of claims 1 to 9.

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