CN111057252B

CN111057252B - Controllable-removal strong-adhesion hydrogel and preparation method thereof

Info

Publication number: CN111057252B
Application number: CN202010009207.0A
Authority: CN
Inventors: 罗晓民; 霍倩倩; 刘新华; 冯见艳; 张鹏; 郑驰; 刘颖; 王怡然
Original assignee: Shaanxi University of Science and Technology
Current assignee: Shaanxi University of Science and Technology
Priority date: 2020-01-06
Filing date: 2020-01-06
Publication date: 2022-11-25
Anticipated expiration: 2040-01-06
Also published as: CN111057252A

Abstract

A multifunctional hydrogel adhesive with excellent wet-state adhesion, rapid degradation and controllable removal is composed of two parts of a double network. The first network is gelatin containing catechol groups and the second network is hyaluronic acid containing succinimide succinate groups. The hydrogel was obtained by mixing the two components in PBS solution. Upon contact of the hydrogel with the tissue, the residual succinimidyl succinate groups and catechol groups in the network react with the amino groups on the tissue protein, and these chemical bonds result in stronger bonds between the tissue and the hydrogel than commercial fibrin glue. The introduction of the cyclized succinic acid ester group into the hydrogel matrix enables the hydrogel to have the characteristics of rapid degradation and controllable removal.

Description

Controllable-removal strong-adhesion hydrogel and preparation method thereof

Technical Field

The invention relates to medical gelatin hydrogel and also relates to a preparation method of the strong-adhesion multifunctional hydrogel.

Background

Uncontrolled bleeding and wound infections have been one of the leading causes of death in the medical field. Improper wound management not only prolongs healing time, but also increases the risk of infection, increases the likelihood of death, and increases economic burden. The traditional method of hemostasis is to press the wound with cotton gauze, but the gauze absorbs blood and causes inevitable blood loss. Meanwhile, absorbed blood can form a tight whole with the gauze, and wound tearing and secondary bleeding and even infection are caused in the process of removing the gauze. The biological adhesive is a biological medical material which can fill, seal, stop bleeding and adhere wounds, has the bonding performance of common adhesives and has a plurality of functions meeting the requirements of biological medical application. With the rapid development of modern medicine, the clinical requirement on wound adhesion is higher and higher, so that the pain of a patient is reduced to the greatest extent, the wound healing time is shortened, the wound is required to be free of scars as far as possible after healing, the appearance is attractive, the traditional suture mode is inconvenient to operate, the pain of the patient is increased due to frequent stitch removal, the wound is easy to infect, the scar is left after healing and the like, and the traditional suture mode is undoubtedly unacceptable for many patients. Therefore, there is an increasing demand for medical adhesives, and hydrogels are often used as adhesives as a soft material, often with good biocompatibility, and can provide a microenvironment simulating extracellular matrix for cells, thereby being widely studied in the fields of tissue engineering and regenerative medicine. Therefore, there is a need for a hydrogel adhesive that can stop bleeding quickly without causing difficulty in removal, and that can stop bleeding quickly without causing secondary damage to the wound.

Disclosure of Invention

The invention aims to solve the problems that the existing hydrogel material is only suitable for bonding under a dry condition, and the integration of the hydrogel material and the surface of organism tissue is seriously hindered by a hydrogen bond failure effect caused by a humid physiological environment and the inherent high water content of the hydrogel, and the like. The adhesives currently in commerce need to be removed by mechanical debridement or surgical excision, and the hydrogels not only provide rapid hemostasis during emergency bleeding, strive for rescue time for the patient, but also provide controlled removal by the PBS solution when the wound needs to be exposed a second time for further treatment. In addition, the hydrogel has good biocompatibility and biodegradability, so that the actual requirements in the field of biomedicine can be met.

The technical scheme adopted by the invention for solving the technical problems is as follows: a strong-adhesion hydrogel adhesive with controllable removal is characterized in that: consists of two parts of a double network, the first network is gelatin containing catechol groups, and the second network is hyaluronic acid containing succinimide succinate groups.

The preparation method of the controllable-removal strong-adhesion hydrogel adhesive is characterized by comprising the following steps of:

(1) Preparation of catechol group-containing gelatin: dissolving 10-20% w/v gelatin in deionized water at 50 ℃, magnetically stirring until the gelatin is completely dissolved, then adding dopamine into the gelatin solution, uniformly stirring, wherein the mass ratio of the dopamine to the gelatin is 10-20%, then adding a natural cross-linking agent into the solution, wherein the mass ratio of the natural cross-linking agent to the gelatin is 10-20%, dialyzing with the deionized water after full reaction, and freeze-drying for later use.

(2) Preparation of hyaluronic acid containing succinimide succinate: dissolving 0.5-0.8% w/v hyaluronic acid in deionized water at 37 ℃, magnetically stirring until the hyaluronic acid is completely dissolved, then adding succinic anhydride into the hyaluronic acid solution, and uniformly stirring, wherein the molar ratio of the succinic anhydride to the hyaluronic acid is 0.7:1-2.5, then adding N-hydroxysuccinimide into the solution, wherein the molar ratio of N-hydroxysuccinimide to succinic anhydride is 1.

(3) The lyophilized gelatin foam and hyaluronic acid foam were dissolved in two sample vials in a 37 ℃ PBS solution (7.4), respectively. Then, the two components were mixed with a double syringe to prepare a hydrogel. The final concentration is 0.625%/2.5% -2.5%/5.0% hyaluronic acid/gelatin.

Natural cross-linking agents include, but are not limited to, genipin, citric acid, and the like.

The hydrogel prepared by the preparation method can be used for uncontrollable bleeding after trauma or in operation, can realize good wet-state adhesion (such as water, PBS buffer solution and blood environment), has the adhesion time within 60 s and the in-vitro degradation time of 48 h, has good biocompatibility and adhesion force, and has the effects of adhering wounds, stopping bleeding and the like.

The invention has the following remarkable advantages: the invention is designed aiming at the problems that the existing hydrogel is only suitable for bonding under a dry condition, a humid physiological environment, a hydrogen bond failure effect caused by inherent high water content of the hydrogel and the like, a catechol group and a succinimide succinate group are introduced into a hydrogel system, a first network is prepared by chemical grafting of a component containing the catechol group and gelatin, the catechol group is easily oxidized into a quinone or semiquinone structure, and at the moment, the catechol group can not only carry out Michael addition and Schiff base reaction with amino, imino, sulfydryl and other groups, but also can carry out intramolecular cyclization to form a dehydroindole structure, and carry out disproportionation reaction to form a free radical which is further coupled into a tannin compound, finally form polymerization crosslinking, enhance the adhesion and cohesion between the hydrogel and a wet tissue, have good wet adhesion, and can use the prepared hydrogel to rapidly stop bleeding when bleeding is emergent, and strive for rescue and rescue time for a patient; the second network was prepared by chemical grafting of the succinimide succinate group with hyaluronic acid, which in turn could be controllably removed by a PBS solution when a second exposure of the wound was required for further treatment. Thereby meeting the actual requirements of the field of biological medicine. When applied to a wound, the hydrogel binds strongly to the skin. In particular, the synthesized material has no cytotoxicity, good biocompatibility and biodegradability, and can meet the safety requirement of the biomedical field on the material.

Drawings

FIG. 1 is a photograph of the hydrogel prepared in example 2.

Figure 2 is a schematic of the dissolution of the hydrogel prepared in example 2 controlled by wiping the PBS solution on both the flat and perforated pigskins.

Detailed Description

In order to verify the feasibility of the design, the technical solution of the present invention is further described below with reference to the specific embodiments, but the application of the present invention is not limited thereto.

Examples example 1

Gelatin was dissolved in PBS at 50 ℃ to make a 10% w/v homogeneous solution. Then 100 mg dopamine per gram gelatin is added into the gelatin solution and stirred evenly, and then 6 mg genipin per gram gelatin is added into the mixed solution at the speed of 0.5 mL/min and stirring is continued. The mixture was reacted at 37 ℃ for 6 h. The gelatin solution was dialyzed with deionized water for 3 days using an 8-14 kDa cut-off dialysis bag to remove unreacted dopamine, genipin and any by-products. Freeze drying for use. The second network, hyaluronic acid, was prepared in a two-step process. First, hyaluronic acid (1 g), succinic anhydride (180 mg) were reacted in distilled water (100 mL) for 24 hours to prepare hyaluronic acid succinic acid, which was dialyzed with deionized water using a 2 kDa cut-off dialysis bag for 3 days. N-hydroxysuccinimide (200 mg) was then dissolved in distilled water (100 mL). The system was stirred at 37 ℃ for 24 h and dialyzed against deionized water using a 2 kDa cut-off dialysis bag for 3 days. Freeze drying for use. The above lyophilized gelatin foam and hyaluronic acid foam were dissolved in two sample bottles, respectively, in a PBS solution (7.4) at 37 ℃. Then, the two components were mixed with a double syringe to prepare a hydrogel. The final concentration was 1.25% hyaluronic acid/5.0% gelatin.

Example 2

Gelatin was dissolved in PBS at 50 ℃ to make a 10% w/v homogeneous solution. Then 200 mg dopamine per gram gelatin is added into the gelatin solution and stirred evenly, and then 12 mg genipin per gram gelatin is added into the mixed solution at the speed of 0.5 mL/min and the stirring is continued. The mixture was reacted at 50 ℃ for 12 h. The gelatin solution was dialyzed against deionized water using an 8-14 kDa cut-off dialysis bag for 3 days to remove unreacted dopamine, genipin and any by-products. Freeze drying for use. The second network, hyaluronic acid, was prepared in a two-step process. First, hyaluronic acid (1 g), succinic anhydride (180 mg) were reacted in distilled water (100 mL) for 24 hours to prepare hyaluronic acid succinic acid, which was dialyzed against deionized water using a 2 kDa cut-off dialysis bag for 3 days. N-hydroxysuccinimide (436 mg) was then dissolved in distilled water (100 mL). The system was stirred at 37 ℃ for 24 h and dialyzed against deionized water using a 2 kDa cut-off dialysis bag for 3 days. Freeze drying for use. The above lyophilized gelatin foam and hyaluronic acid foam were dissolved in two sample bottles, respectively, in a PBS solution (7.4) at 37 ℃. Then, the two components were mixed with a double syringe to prepare a hydrogel. The final concentration was 2.5% hyaluronic acid/7.5% gelatin.

FIG. 1 is a photograph of a hydrogel prepared in this example. FIG. 1 (a) is a visual photograph of a hydrogel, and FIGS. 1 (b-c) are photographs of the prepared hydrogel twisted to adhere to skin tissue. The pigskin is soaked in PBS solution in advance, and the wet adhesion of the hydrogel to the pigskin is researched through a torsion experiment. Briefly, the hydrogel was formed in situ on the surface of the pigskin using a syringe. Then, torsional stresses in different directions are applied to the pigskin, and the adhesion flexibility of the pigskin is tested.

FIG. 2 is a hydrogel prepared in this example, the dissolution of which was controlled by wiping the PBS solution on the flattened (a) and perforated (b) pigskins. The prepared hydrogel was gelled on the surface of pig skin, and the hydrogel was wiped with a 5 wt% PBS solution. The hydrogels prepared could be cleaned on smooth pigskin in 2 minutes, and importantly, even for hydrogels in irregular wound crevices, they could be rapidly cleared within 4 minutes, and controlled removal experiments fully demonstrated the clinical advantages of the hydrogels prepared when secondary exposure of the wound was required.

Claims

1. A composition for preparing a controlled removal strongly adherent hydrogel, comprising a gelatin-based hydrogel containing catechol groups and a hyaluronic acid hydrogel containing succinimide succinate groups;

the catechol group-containing gelatin-based hydrogel is obtained by reacting a catechol group-containing component with amino groups on gelatin through a natural cross-linking agent by a method comprising the following steps:

dissolving 10-20 g/100 ml of gelatin in deionized water at 50 ℃, and magnetically stirring until the gelatin is completely dissolved; then adding dopamine into the gelatin solution, and uniformly stirring, wherein the mass ratio of dopamine to gelatin is (10-20): 100; then adding a natural cross-linking agent into the solution, wherein the mass ratio of the natural cross-linking agent to the gelatin is (10-20): 100; dialyzing with deionized water after full reaction, and freeze-drying;

the component containing catechol groups is dopamine;

the natural cross-linking agent is one or more of genipin and citric acid;

the hyaluronic acid hydrogel containing succinimide succinic acid ester groups is obtained by reacting a component containing succinimide succinic acid ester groups with hydroxyl groups on hyaluronic acid, and comprises the following steps:

dissolving 0.5-0.8 g/100 ml hyaluronic acid in deionized water at 37 deg.C, and magnetically stirring to dissolve completely; then adding succinic anhydride into the hyaluronic acid solution, and uniformly stirring, wherein the molar ratio of the succinic anhydride to the hyaluronic acid is (0.7-2.5): 1; then adding N-hydroxysuccinimide into the solution, wherein the molar ratio of the N-hydroxysuccinimide to the succinic anhydride is 1; after full reaction, dialyzing with deionized water, and freeze-drying.

2. A preparation method of a controllable-removal strong-adhesion hydrogel is characterized by comprising the following steps: mixing the catechol group-containing gelatin-based hydrogel of claim 1 with the succinimide succinate group-containing hyaluronic acid hydrogel of claim 1 to obtain a strongly adherent hydrogel with controlled removal.

3. The method of claim 2, comprising the steps of: respectively dissolving freeze-dried gelatin-based hydrogel containing catechol groups and freeze-dried hyaluronic acid hydrogel containing succinimide succinate groups in a PBS (phosphate buffer solution) solution with the pH =7.4, and mixing the two dispersions by using a double syringe to prepare hydrogel; the mass concentration of hyaluronic acid in the finally obtained hydrogel is 0.625% -2.5%, and the mass concentration of gelatin is 2.5% -5.0%.

4. A strongly adherent hydrogel which is controllably removable by a process as defined in claim 2 or 3.