Bi-crosslinked gelatin-based hydrogel wound dressing as well as preparation method and application thereof

Abstract

The invention discloses a bi-crosslinking gelatin-based hydrogel wound dressing as well as a preparation method and application thereof, and belongs to the technical field of biomedical materials. The preparation method disclosed by the invention comprises the following steps: mixing a gelatin solution and an oxidized konjac glucomannan solution, heating and stirring to obtain a hydrogel precursor solution; and mixing the hydrogel precursor solution with a borax solution to obtain the bi-crosslinked gelatin-based hydrogel wound dressing. According to the method, oxidized konjac glucomannan and gelatin are subjected to Schiff base and Schiff base crosslinking, borax is further added to introduce a dynamic boric acid ester bond effect to enhance a three-dimensional network of the hydrogel, and the dynamic reversible Schiff base effect and the boric acid ester bond effect are enhanced, so that the pore diameter and the swelling ratio of the hydrogel are increased, and the gel strength of the hydrogel is enhanced; due to the good self-healing injectable performance, biodegradability and mechanical property of the hydrogel, the hydrogel can be used as a wound dressing for irregular deep skin wounds, and the technical problem that existing hydrogel is insufficient in treatment of irregular wounds is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical materials, and particularly relates to a double-crosslinked gelatin-based hydrogel wound dressing, a preparation method thereof, and an application thereof. Background Art

[0002] As an important organ of the human epidermal system, the skin can protect the body from the external environment, but at the same time it is also one of the most vulnerable organs in the human body. Due to the complexity of wound healing, the treatment of trauma has always been a clinical challenge worldwide. Traditional wound dressings such as gauze and bandages have limited effects in promoting wound healing and preventing bacterial infection. The granulation tissue of the wound often grows into the mesh of the dressing and is difficult to remove without damaging the new tissue. The hemostatic effect and barrier function are poor, and there is a risk of causing exogenous infection.

[0003] Hydrogel dressings have shown significant advantages in the field of wound care due to their unique physical and chemical properties and biological functions, and have become potential candidate materials. Hydrogels are three-dimensional network structures formed by hydrophilic polymers through physical or chemical crosslinking. There are a large number of hydrogen bonds and van der Waals forces between their molecular chains, enabling them to absorb a large amount of water in water (usually dozens to hundreds of times their own weight) without dissolving, while maintaining structural integrity, thus providing a stable moist environment for the wound surface, meeting the requirements of the modern moist healing theory. This moist microenvironment can effectively prevent the wound surface from dehydration and necrosis, promote the migration of keratinocytes and angiogenesis, and at the same time reduce mechanical damage and pain during dressing change. From the perspective of biocompatibility, the main components of hydrogels such as polyvinyl alcohol, polyethylene glycol, hyaluronic acid, and collagen all have good biological safety and will not cause obvious immune rejection reactions or interfere with the normal cell metabolism process. In addition, the porous structure and high specific surface area characteristics of hydrogels make them excellent drug carriers, which can load various antibacterial drugs (such as gentamicin, silver ions), growth factors (such as epidermal growth factor, vascular endothelial growth factor), or antioxidants (such as gallic acid, vitamin E) through physical embedding, electrostatic adsorption, or covalent binding, etc., to achieve controlled release of drugs and synergistic treatment. However, traditional hydrogel dressings are usually prepared by a pre-forming process, with fixed shapes and sizes, and it is difficult to fully conform to common irregular wound surfaces in clinics (such as deep cavity wounds or joint activity parts), resulting in gaps at the dressing-wound surface interface, affecting the treatment effect. This lack of morphological adaptability may also lead to dressing displacement or fluid accumulation, increasing the risk of infection. Summary of the Invention

[0004] The purpose of the present invention is to provide a double-crosslinked gelatin-based hydrogel wound dressing, a preparation method thereof, and an application thereof, so as to solve the technical problem that the existing hydrogels are pre-formed scaffolds, resulting in insufficient treatment of irregular wound surfaces.

[0005] To achieve the above object, the present invention is implemented by the following technical solutions:

[0006] The present invention discloses a preparation method of a double-crosslinked gelatin-based hydrogel wound dressing, comprising the following steps:

[0007] Mix a gelatin solution and an oxidized konjac glucomannan solution, and stir to obtain a hydrogel precursor solution;

[0008] Mix the hydrogel precursor solution and a borax solution to obtain a double-crosslinked gelatin-based hydrogel wound dressing.

[0009] Further, the gelatin solution and the oxidized konjac glucomannan solution are prepared by separately dispersing gelatin and oxidized konjac glucomannan in deionized water and heating and stirring;

[0010] The oxidized konjac glucomannan is prepared by oxidizing konjac glucomannan with sodium periodate.

[0011] Further, the temperature of the heating and stirring is 60 °C, and the time is 0.5 - 1 h.

[0012] Further, the mass concentration of the gelatin solution is 16 - 19 wt%; the mass concentration of the oxidized konjac glucomannan solution is 1 - 5 wt%.

[0013] Further, the stirring speed is 300 - 500 rpm, the temperature is 40 - 60 °C, and the time is 2 - 3 h.

[0014] Further, the volume ratio of the gelatin solution to the oxidized konjac glucomannan solution is 1:1.

[0015] Further, the borax solution is prepared by dissolving borax in deionized water; the mass concentration of the borax solution is 3.5 - 14 wt%.

[0016] Further, the volume ratio of the hydrogel precursor solution to the borax solution is 6:1.

[0017] The present invention also discloses a double-crosslinked gelatin-based hydrogel wound dressing prepared by the above preparation method.

[0018] The present invention also discloses the application of the above double-crosslinked gelatin-based hydrogel wound dressing in wound protection.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention discloses a preparation method of a double-crosslinked gelatin-based hydrogel wound dressing. By using oxidized konjac glucomannan and gelatin to undergo Schiff base crosslinking, and further adding borax to introduce dynamic borate ester bonds to enhance its three-dimensional network, the dynamic reversible Schiff base action and borate ester bond action are enhanced, thereby increasing the pore size and swelling ratio of the hydrogel, enhancing the gel strength of the hydrogel. The good self-healing injectable performance, biodegradability and mechanical properties of the hydrogel enable it to be used as a wound dressing for irregular deep skin wounds, solving the technical problem of the insufficient treatment of irregular wound surfaces by existing hydrogels.

[0021] Furthermore, the gelatin used in the present invention has many characteristics of collagen, such as good biocompatibility, the ability to maintain a moist wound environment, etc., and allows oxygen to penetrate into damaged tissues. Oxidized konjac glucomannan can be used as a crosslinking agent to prepare hydrogels, which is more biocompatible than chemical crosslinking agents.

[0022] Furthermore, the preparation method of the present invention is simple, has low requirements for reactions, and is conducive to large-scale production. The hydrogel prepared by the method provided by the present invention has good biocompatibility, wound healing promotion ability and hemostatic effect as a wound dressing, and has the potential for application in wound healing. Description of the Drawings

[0023] Figure 1 It is a test chart of the self-healing performance, injectable performance and shape self-adaptability performance of the double-crosslinked gelatin-based hydrogel wound dressing prepared by the present invention;

[0024] Figure 2 It is a scanning electron microscope image of the double-crosslinked gelatin-based hydrogel wound dressing prepared by the present invention;

[0025] Among them: taking "0-1" as an example, "0" represents that the content of oxidized konjac glucomannan in the hydrogel is 0%, and "1" represents that the content of borax in the hydrogel is 1%;

[0026] Figure 3 It is an infrared spectrum diagram of the double-crosslinked gelatin-based hydrogel wound dressing prepared by the present invention;

[0027] Figure 4 It is a swelling ratio result chart of the double-crosslinked gelatin-based hydrogel wound dressing prepared by the present invention;

[0028] Among them: a - the swelling ratio of hydrogels with different oxidized konjac glucomannan contents (0.5%-2%); b - the swelling ratio of hydrogels with different borax contents (0%-2%); Different lowercase letters indicate significant differences (p<0.05);

[0029] Figure 5The gel strength result diagram of the double-crosslinked gelatin-based hydrogel wound dressing prepared in the present invention;

[0030] Among them: a - the gel strength of hydrogels with different konjac glucomannan oxide contents (0% - 2%); b - the gel strength of hydrogels with different borax contents (0% - 2%); Different lowercase letters indicate significant differences (p < 0.05);

[0031] Figure 6 The degradation rate result diagram of the double-crosslinked gelatin-based hydrogel wound dressing prepared in the present invention;

[0032] Among them: a - the degradation rate of hydrogels with different konjac glucomannan oxide contents (0.5% - 2%); b - the degradation rate of hydrogels with different borax contents (0% - 2%);

[0033] Figure 7 The cell survival rate result diagram when the double-crosslinked gelatin-based hydrogel wound dressing prepared in the present invention is used to culture L929 cells for 24 h and 48 h;

[0034] Figure 8 The hemostasis effect diagram of the double-crosslinked gelatin-based hydrogel wound dressing prepared in the present invention and medical gauze;

[0035] Among them: a - the blank group (without treatment), the bleeding volume after treating mouse liver injury in the gauze group and the hydrogel group; b - the in-situ hemostasis photos after treating mouse liver injury in the blank group (without treatment), the gauze group and the hydrogel group; Compared with the blank group, *p < 0.05, **p < 0.01, **p < 0.001, ns, no significant difference;

[0036] Figure 9 The photos taken at different time points within two weeks of wound closure using the double-crosslinked gelatin-based hydrogel wound dressing prepared in the present invention and medical gauze. Detailed implementation manners

[0037] To enable those skilled in the art to understand the features and effects of the present invention, the following provides a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein shall have the ordinary meaning understood by those skilled in the art for the present invention. In case of conflicts, the definitions in this specification shall prevail.

[0038] The theories or mechanisms described and disclosed herein, whether correct or incorrect, shall not limit the scope of the present invention in any way, that is, the content of the present invention can be implemented without being limited by any specific theory or mechanism.

[0039] In this text, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are only for the sake of brevity and convenience. Accordingly, the description of a numerical range or percentage range should be regarded as having covered and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0040] In this text, unless otherwise specified, terms such as "comprising", "including", "containing", "having", or similar terms cover the meanings of "consisting of" and "consisting essentially of". For example, "A comprises a" covers the meanings of "A comprises a and others" and "A consists only of a".

[0041] In this text, for the sake of brevity of description, all possible combinations of all technical features in each embodiment or example are not described. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered to be within the scope described in this specification.

[0042] The present invention provides a method for preparing a double-crosslinked gelatin-based hydrogel wound dressing. First, Schiff base crosslinking occurs between the aldehyde groups in oxidized konjac glucomannan and the amino groups in type B gelatin, and then borax is further added to introduce dynamic borate ester bonds to enhance its three-dimensional network, thereby obtaining a double-crosslinked gelatin-based hydrogel wound dressing. The method specifically includes the following steps:

[0043] S1: Gelatin and oxidized konjac glucomannan are respectively dispersed in deionized water, and a gelatin solution and an oxidized konjac glucomannan solution are prepared by heating and stirring; then, the same volume of the two is taken and mixed and stirred to obtain a hydrogel precursor solution;

[0044] S2: Borax is dissolved in deionized water to prepare a borax solution, which is then mixed with the hydrogel precursor solution obtained in step S1 to obtain a gelatin-oxidized konjac glucomannan-borax hydrogel (double-crosslinked gelatin-based hydrogel wound dressing).

[0045] Preferably, in S1, the oxidized konjac glucomannan is prepared by oxidizing konjac glucomannan with sodium periodate.

[0046] Preferably, in S1, the mass concentration of the gelatin solution is 16-19 wt%, and the mass concentration of the oxidized konjac glucomannan solution is 1-5 wt%.

[0047] Preferably, in S1, the heating and stirring temperature is 60 °C, and the time is 0.5-1 h.

[0048] Preferably, in S1, the mixing and stirring speed of the gelatin solution and the oxidized konjac glucomannan solution is 300-500 rpm, the temperature is 40-60 °C, and the time is 2-3 h.

[0049] Preferably, in S1, the same volume is taken for the two, and each takes 3 mL.

[0050] Preferably, in S2, the mass concentration of the borax solution is 3.5 - 14 wt%.

[0051] Preferably, in S2, the volume ratio of the hydrogel precursor solution to the borax solution is 6:1.

[0052] The above preparation method specifically comprises the following steps:

[0053] S1: Prepare a 600 mL konjac glucomannan (KGM) solution with a mass concentration of 1%, heat and stir at 60 °C for 3 - 5 h until uniform, add 1.58 g of sodium periodate (NaIO4), stir and react in the dark in a 40 °C water bath for 6 h, then add ethylene glycol (10 mL) to remove the unreacted NaIO4, continue to stir for 2 h, then put the solution into a dialysis bag (MWCO: 3500 Da), and dialyze in deionized water for 3 d until there is no iodate in the dialysis solution, and freeze-dry to obtain oxidized konjac glucomannan (OKG);

[0054] Disperse gelatin (GB) and OKG in deionized water respectively, heat and stir at 60 °C for 2 h to prepare a GB solution with a mass concentration of 16 - 19 wt% and an OKG solution with a mass concentration of 1 - 5 wt%. Take 3 mL each of the two, mix and stir at 60 °C and 300 - 500 rpm for 2 - 3 h to obtain a hydrogel precursor solution;

[0055] S2: Dissolve borax in deionized water to prepare a 2 - 14 wt% borax solution, and then mix it with the hydrogel precursor solution obtained in step S1 to obtain a double-crosslinked gelatin-based hydrogel wound dressing.

[0056] The following further illustrates the present invention with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0057] The following embodiments use conventional instruments and equipment in the art. The experimental methods without specific conditions noted in the following embodiments are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer. Various raw materials used in the following embodiments are all conventional commercially available products unless otherwise stated, and their specifications are conventional specifications in the art. In the specification of the present invention and the following embodiments, unless otherwise specified, "%" all represents weight percentage, "parts" all represents weight parts, and the ratio all represents weight ratio.

[0058] Example 1

[0059] A preparation method of a double-crosslinked gelatin-based hydrogel wound dressing specifically includes the following steps:

[0060] S1: Disperse GB and OKG separately in deionized water, heat and stir at 60 °C for 2 h to obtain a GB solution with a mass concentration of 18.7% and an OKG solution with a mass concentration of 1.1%. Take 3 mL of each of the two solutions and mix and stir at 60 °C and 400 rpm for 2 h to obtain a hydrogel precursor solution;

[0061] S2: Add 1 mL of 7 wt% borax solution to the hydrogel precursor solution, stir to crosslink it, and cool it at room temperature to obtain a double-crosslinked gelatin-based hydrogel wound dressing (GB-OKG-borax hydrogel).

[0062] Example 2

[0063] A preparation method of a double-crosslinked gelatin-based hydrogel wound dressing specifically includes the following steps:

[0064] S1: Disperse GB and OKG separately in deionized water, heat and stir at 60 °C for 2 h to obtain a GB solution with a mass concentration of 18.7% and an OKG solution with a mass concentration of 2.3%. Take 3 mL of each of the two solutions and mix and stir at 60 °C and 400 rpm for 2 h to obtain a hydrogel precursor solution;

[0065] S2: Add 1 mL of 7 wt% borax solution to the hydrogel precursor solution, stir to crosslink it, and cool it at room temperature to obtain a double-crosslinked gelatin-based hydrogel wound dressing.

[0066] Example 3

[0067] A preparation method of a double-crosslinked gelatin-based hydrogel wound dressing specifically includes the following steps:

[0068] S1: Disperse GB and OKG separately in deionized water, heat and stir at 60 °C for 2 h to obtain a GB solution with a mass concentration of 18.7% and an OKG solution with a mass concentration of 3.5%. Take 3 mL of each of the two solutions and mix and stir at 60 °C and 400 rpm for 2 h to obtain a hydrogel precursor solution;

[0069] S2: Add 1 mL of 7 wt% borax solution to the hydrogel precursor solution, stir to crosslink it, and cool it at room temperature to obtain a double-crosslinked gelatin-based hydrogel wound dressing.

[0070] Example 4

[0071] A preparation method of a double-crosslinked gelatin-based hydrogel wound dressing specifically includes the following steps:

[0072] S1: Disperse GB and OKG separately in deionized water, heat and stir at 60 °C for 2 h to obtain a GB solution with a mass concentration of 18.7% and an OKG solution with a mass concentration of 4.6%. Take 3 mL of each of them and mix and stir at 60 °C and 400 rpm for 2 h to obtain a hydrogel precursor solution;

[0073] S2: Add 1 mL of 7 wt% borax solution to the hydrogel precursor solution, stir to crosslink it, and cool it at room temperature to obtain a double-crosslinked gelatin-based hydrogel wound dressing.

[0074] Example 5

[0075] A preparation method of a double-crosslinked gelatin-based hydrogel wound dressing specifically includes the following steps:

[0076] S1: Disperse GB and OKG separately in deionized water, heat and stir at 60 °C for 2 h to obtain a GB solution with a mass concentration of 18.7% and an OKG solution with a mass concentration of 4.6%. Take 3 mL of each of them and mix and stir at 60 °C and 400 rpm for 2 h to obtain a hydrogel precursor solution;

[0077] S2: Add 1 mL of 3.5 wt% borax solution to the hydrogel precursor solution, stir to crosslink it, and cool it at room temperature to obtain a double-crosslinked gelatin-based hydrogel wound dressing.

[0078] Example 6

[0079] A preparation method of a double-crosslinked gelatin-based hydrogel wound dressing specifically includes the following steps:

[0080] S1: Disperse GB and OKG separately in deionized water, heat and stir at 60 °C for 2 h to obtain a GB solution with a mass concentration of 18.7% and an OKG solution with a mass concentration of 4.6%. Take 3 mL of each of them and mix and stir at 60 °C and 400 rpm for 2 h to obtain a hydrogel precursor solution;

[0081] S2: Add 1 mL of 10.5 wt% borax solution to the hydrogel precursor solution, stir to crosslink it, and cool it at room temperature to obtain a double-crosslinked gelatin-based hydrogel wound dressing.

[0082] Example 7

[0083] A preparation method of a double-crosslinked gelatin-based hydrogel wound dressing specifically includes the following steps:

[0084] S1: Disperse GB and OKG separately in deionized water, heat and stir at 60 °C for 2 h to obtain a GB solution with a mass concentration of 18.7% and an OKG solution with a mass concentration of 4.6%. Take 3 mL of each of them and mix and stir at 60 °C and 400 rpm for 2 h to obtain a hydrogel precursor solution;

[0085] S2: Add 1 mL of 14 wt% borax solution to the hydrogel precursor solution, stir to crosslink it, and cool it at room temperature to obtain a double-crosslinked gelatin-based hydrogel wound dressing.

[0086] Comparative Example 1

[0087] Disperse GB in deionized water, heat and stir at 60 °C for 2 h to obtain a GB solution with a mass concentration of 16%. Add 3 mL of 2 wt% borax solution to 3 mL of the GB solution with a mass concentration of 16%, stir evenly, and cool it at room temperature to obtain GB-borax hydrogel.

[0088] Comparative Example 2

[0089] Disperse GB and OKG in deionized water respectively, heat and stir at 60 °C for 2 h to obtain a GB solution with a mass concentration of 16% and an OKG solution with a mass concentration of 4%. Take 3 mL of each of them, mix and stir at 60 °C and 300 - 500 rpm for 2 h, and cool it at room temperature to obtain GB-OKG hydrogel.

[0090] Table 1 summarizes the final concentrations of GB, OKG, and borax solution prepared in different examples and comparative examples.

[0091] Table 1 Final Concentrations of GB, OKG, and Borax Solution Prepared

[0092]

[0093] Macroscopically test the self-healing property of the hydrogel. Cut the hydrogel in half, stain one half with rhodamine B, then bring the cut interfaces into contact with each other, record the self-healing process and time of the hydrogel. Select Example 4 to test its injectability. Before complete gelation, immediately add the sol to a syringe. After gelation, write "SUST" on a flat plate with the syringe, take a photo for record. At the same time, inject it into molds of different shapes, demold, and take a photo for record. The results are as Figure 1 shown. It can be Figure 1 seen that the hydrogel can be continuously injected through a syringe to draw the letter "SUST", and the hydrogel can also be injected into molds of any shape and then form various complex 3D shapes; the ability of the hydrogel to adapt to different shapes indicates that it can closely cover irregular wounds. In addition, the hydrogel in Example 4 can self-heal in only 10 min, indicating that the hydrogel has good self-healing ability.

[0094] Use a scanning electron microscope (SEM) to observe the influence of different OKG and borax contents on the internal microstructure of the hydrogel. The results are as Figure 2 shown. It can be Figure 2It can be seen that as the OKG content increases, the pore size increases, which is due to the Schiff base interaction between gelatin and OKG molecules and the borate ester bond interaction between OKG and borax; as the borax content increases, the pore size of the hydrogel increases from 12.62±0.78μm to 21.49±0.31μm, and the pore sizes of the hydrogels with more than 1% borax content are not very different, which may be due to the insufficient cross-linking sites between borax and OKG.

[0095] An FT-IR spectrometer was used to test OKG, GB, borax, and the freeze-dried hydrogel. The test parameters are as follows: the test wavelength range is 4000-400 cm-1, the number of scans is set to 64 times, and the spectrum is recorded at a resolution of 4 cm -1 , and the results are as Figure 3 shown. From Figure 3 it can be seen that the characteristic peaks at 1640 cm -1 and 1531 cm -1 in the infrared spectrum of GB are attributed to the C=O stretching vibration peak of amide I and the N-H bending vibration peak and C-N stretching vibration peak of amide II; in the infrared spectrum of the GB-OKG hydrogel, the aldehyde group characteristic peak of OKG at 1730 cm -1 disappears, and a characteristic peak at 1670 cm -1 (C=N double bond) appears, indicating that the aldehyde group participates in the formation of imine bonds, proving the existence of Schiff base interaction in the GB-OKG hydrogel network. After further introducing borax, characteristic peaks at 1360 cm -1 and 1240 cm -1 appear in the infrared spectrum of the GB-OKG-Borax hydrogel, which are the asymmetric stretching vibration peaks of the B-O-C complex, proving the formation of borate ester bonds. This may be because the tetrahydroxyborate ion [B(OH) 4- generated after borax reacts with water can react with the -OH that has not been fully oxidized on OKG, promoting the formation of borate ester bonds.

[0096] The swelling properties of the hydrogel were measured by gravimetric analysis. The dry gel sample was weighed and recorded as W0. At 37°C, the dry hydrogel was placed in PBS with a pH of 7.4 for 24 h and then weighed, and the weight of the gel sample was recorded. This process was repeated every 1 h until the weight of the hydrogel reached a constant weight, which was recorded as Wt. The swelling ratio of the hydrogel is as Figure 4 shown, and the swelling ratio of the hydrogel is calculated by the following formula:

[0097]

[0098] From Figure 4a) It can be seen that the addition of OKG significantly increases the swelling ratio of the hydrogel. The swelling ratio of the 2% OKG hydrogel can reach 793 ± 44%, which is consistent with the above-mentioned trend of the pore size of the hydrogel. The larger the pore size, the stronger the water absorption ability. From Figure 4 b) It can be seen that when the OKG content is constant, compared with the hydrogels with low borax content (0% - 0.5%), the swelling ratio of the hydrogels with high borax content (1% - 2%) increases, and there is no significant difference in the swelling ratio among the hydrogels with high borax content.

[0099] Gel strength measurement: Use a mold to make the hydrogel into a cylinder with a diameter of 12 mm and a height of 12 mm. Use a texture analyzer to measure the gel strength of the hydrogel. Calibrate its measured height and weight before testing; set the parameters as follows: the compression deformation is 75%, the trigger force is 5 g, and the test rate is 1 mm / s. Adopt the puncture mode and select the probe model P / 0.5. The gel strength results are as Figure 5 shown.

[0100] The influence of different OKG contents on the gel strength is as Figure 5 shown in a). As the OKG content increases from 0% to 2%, the gel strength increases by about three times. This may be because when the borax content remains unchanged, with the increase of the OKG content, the number of groups on the OKG molecular chain that can crosslink with gelatin and borax increases, resulting in the enhancement of the gel skeleton network strength by the borate ester bonds and imine bonds in the hydrogel network structure. The influence of different borax contents on the gel strength is as Figure 5 shown in b). Compared with the control group, the gel strength of the hydrogel containing borax can be increased by about 10 kPa, and there is no significant difference in the gel strength of the hydrogels with borax content of 1% - 2%.

[0101] The in vitro degradation behavior of the hydrogel was characterized by monitoring the weight loss of the hydrogel. Immerse the initially weighed freeze-dried hydrogel (W0) in PBS (pH = 7.4) solution and place it in a thermostatic oscillator (37 °C, 100 rpm); at the time points of 6 h, 12 h, 24 h, 72 h, 120 h, and 168 h, use filter paper to absorb the excess water, freeze-dry and weigh (W t ); The hydrogel degradation rate results are as Figure 6 shown. The hydrogel degradation rate is calculated by the following formula:

[0102]

[0103] In the degradation experiment, the 0% OKG hydrogel quickly dissolved immediately in the 37 °C environment, and the degradation rates of the other groups are as Figure 6As shown in a), the 0.5% and 1% OKG hydrogels were completely degraded within 1 day, the 1.5% OKG hydrogel was completely degraded within 3 days, and the 2% OKG hydrogel was completely degraded within 7 days, with the slowest degradation rate. This indicates that the addition of OKG enhanced the Schiff base interaction and borate ester bond interaction, strengthening the hydrogel network structure. From Figure 6 As shown in b), the 0% borax hydrogel was completely degraded within 5 days. Although the 0.5% borax hydrogel and the 1%-2% borax hydrogels were all completely degraded within 7 days, the 0.5% borax hydrogel had a faster degradation rate on the 1st day, indicating that the borate ester bond interaction strengthened the hydrogel network structure.

[0104] L929 cells (1×10 5 cells / well) were seeded in a 96-well plate. After culturing for 24 h, the culture medium was removed, and the L929 cells were treated with the extraction solutions (25 mg / mL) of the 2-1 group of hydrogels or complete growth medium, with untreated L929 cells as the control group. After co-incubating in a humidified incubator at 37 °C with 5% CO2 for 24 h and 48 h, 200 μL of MTT reagent with a concentration of 0.5 mg / mL was added to each well. After culturing for 4 h, the MTT reagent was aspirated, 200 μL of DMSO was added, and the plate was shaken at 100 rpm on a thermostatic shaker at 37 °C. After 10 min, the absorbance at 490 nm was measured. The results of cell viability are as Figure 7 shown, and the cell viability was calculated according to the following formula:

[0105]

[0106] where: A test refers to the absorbance value of the cells after treatment with the sample; A control refers to the absorbance value of the cells without treatment with the sample; A blank refers to the absorbance value of the solution without adding cell suspension and without treatment with the sample;

[0107] From Figure 7 it can be seen that after the hydrogel extraction solution acted on L929 for different times, the cell viability measured by the MTT method was all above 80%, indicating that the gel was non-toxic to cells and had good cell compatibility.

[0108] The mice were anesthetized and fixed on the operating table. The abdominal cavity was opened to expose the liver of the mice. The weighed filter paper was placed on the paraffin film and placed under the liver to absorb blood. An acute bleeding wound was made on the liver with a scalpel, and immediately the 2-1 group of hydrogel samples were injected to cover the surface of the bleeding site. Medical gauze was used as the control group, and the untreated acute wound surface was used as the blank group. The results are as Figure 8 shown. From Figure 8It can be seen that the blood stain area on the filter paper in the control group was larger, and the blood loss was about 200 mg. The blood loss in the hydrogel group was less, about 33 mg, which was significantly lower than that in the control group and the gauze group (P<0.05), indicating the good hemostatic effect of the hydrogel.

[0109] Using the standard anesthesia procedure, after intraperitoneal injection of anesthetic (tribromoethanol), the dorsal skin of the rats was shaved, and a full-thickness skin incision with a diameter of 6 mm was made using a punch; the wound in the control group was covered with medical gauze, and the sample group was treated with Example 4. The dressing was changed every day, and the wound was photographed. The results are as Figure 9 shown.

[0110] It can be Figure 9 seen that compared with ordinary medical gauze, the double-crosslinked gelatin-based hydrogel wound dressing can more effectively promote wound healing and accelerate skin tissue regeneration.

[0111] The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A preparation method of a double-crosslinked gelatin-based hydrogel wound dressing, characterized in that, It includes the following steps: Mix the gelatin solution and the oxidized konjac glucomannan solution, and obtain a hydrogel precursor solution after stirring; After mixing the hydrogel precursor solution and the borax solution, a double-crosslinked gelatin-based hydrogel wound dressing is obtained.

2. The preparation method of a double-crosslinked gelatin-based hydrogel wound dressing according to claim 1, characterized in that, The gelatin solution and the oxidized konjac glucomannan solution are prepared by dispersing gelatin and oxidized konjac glucomannan in deionized water respectively and then heating and stirring; The oxidized konjac glucomannan is prepared by oxidizing konjac glucomannan with sodium periodate.

3. The preparation method of a double-crosslinked gelatin-based hydrogel wound dressing according to claim 2, characterized in that, The temperature of the heating and stirring is 60 °C, and the time is 0.5 - 1 h.

4. The preparation method of a double-crosslinked gelatin-based hydrogel wound dressing according to claim 1, characterized in that, The mass concentration of the gelatin solution is 16 - 19 wt%; the mass concentration of the oxidized konjac glucomannan solution is 1 - 5 wt%.

5. The preparation method of a double-crosslinked gelatin-based hydrogel wound dressing according to claim 1, characterized in that, The rotation speed of stirring is 300 - 500 rpm, the temperature is 40 - 60 °C, and the time is 2 - 3 h.

6. The preparation method of a double-crosslinked gelatin-based hydrogel wound dressing according to claim 1, characterized in that, The volume ratio of the gelatin solution to the oxidized konjac glucomannan solution is 1:

1.

7. The preparation method of a double-crosslinked gelatin-based hydrogel wound dressing according to claim 1, characterized in that The borax solution is prepared by dissolving borax in deionized water; the mass concentration of the borax solution is 3.5 - 14 wt%.

8. The preparation method of a double-crosslinked gelatin-based hydrogel wound dressing according to claim 1, characterized in that, The volume ratio of the hydrogel precursor solution to the borax solution is 6:

1.

9. A double-crosslinked gelatin-based hydrogel wound dressing, characterized in that, It is prepared by using the preparation method described in any one of claims 1 to 8.

10. Use of the double-crosslinked gelatin-based hydrogel wound dressing described in claim 9 in wound protection.

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