Hydrogel containing tannic acid nanocarbon and preparation method and application thereof

Abstract

The present invention provides a hydrogel containing tannic acid nanocarbon and a preparation method and application thereof. The effective component in the hydrogel includes tannic acid nanocarbon. The hydrogel can solve the problem that the medical materials in the prior art are difficult to promote the healing of chronic wounds of diabetes, and is applicable to the field of nanomaterial technology.

Description

Technical Field

[0001] The invention relates to the technical field of nanomaterials, and in particular to a hydrogel containing tannic acid nanocarbon and a preparation method and application thereof. Background Art

[0002] According to the World Health Organization, approximately 422 million people suffer from diabetes worldwide, and chronic wounds that are difficult to heal are one of the most serious complications for diabetic patients, which can lead to lower limb amputation in severe cases. The wound dressing market is expected to reach $11.2 billion by 2025. There are currently various treatment options proposed, such as antibiotics, nitric oxide therapy, biomaterial gel, etc., but their treatment and effectiveness still face many challenges.

[0003] The chronicity of diabetic wounds is caused by multiple factors such as high blood sugar, bacterial infection, oxidative stress levels and insufficient angiogenesis. Among them, the high blood sugar of diabetic patients causes microvascular lesions and inhibits angiogenesis, which leads to prolonged and difficult healing of diabetic wounds. Therefore, promoting new blood vessel formation is crucial to improving the diabetic microenvironment and promoting wound healing, but there are few treatment strategies in the prior art that can simultaneously and synergistically regulate antibacterial and angiogenesis to provide a healing microenvironment for chronic diabetic wounds. Therefore, the prior art lacks a medical material that can effectively provide a healing microenvironment for chronic diabetic wounds. Summary of the invention

[0004] The main purpose of the present invention is to provide a hydrogel containing tannic acid nanocarbon and a preparation method and application thereof, so as to solve the problem that medical materials in the prior art are difficult to promote the healing of chronic wounds in diabetes.

[0005] In order to achieve the above-mentioned object, according to a first aspect of the present invention, there is provided a use of a hydrogel containing tannic acid nano-carbon in the preparation of a preparation for promoting wound healing, wherein the active ingredient in the hydrogel includes tannic acid nano-carbon.

[0006] Further, promoting wound healing includes promoting angiogenesis at the wound; preferably, the dosage form of the preparation includes an external preparation; preferably, the external preparation includes an ointment, an ointment, a spray, a patch or a lotion.

[0007] Furthermore, the diameter of the tannic acid nanocarbon is 20-100 nm; preferably, the pore size of the tannic acid nanocarbon hydrogel is 10-50 μm.

[0008] In order to achieve the above-mentioned purpose, according to the second aspect of the present invention, a method for preparing a hydrogel in any of the above-mentioned applications is provided, and the preparation method comprises: S1) mixing tannic acid with water and heating the mixture to obtain tannic acid nano-carbon; S2) drying the tannic acid nano-carbon and mixing the mixture with a first solution to obtain a tannic acid nano-carbon solution; S3) mixing the tannic acid nano-carbon solution with a gel matrix to obtain a hydrogel.

[0009] Further, S1) includes: S11) mixing tannic acid with water to obtain a tannic acid solution; S12) placing the tannic acid solution in a reactor and heating it for purification to obtain tannic acid nano-carbon; preferably, the concentration of the tannic acid solution is 2 to 5 wt%; preferably, the reactor includes a polytetrafluoroethylene reactor.

[0010] Further, the purification comprises dialysis; preferably, the dialysis time is 36-72 hours; preferably, the heating temperature is 180-220° C.; preferably, the heating time is 8-12 hours.

[0011] Furthermore, in S2), the concentration of the tannic acid nanocarbon solution is 0.1-2 wt %; preferably, the first solution includes one or more of water, saline or phosphate buffer.

[0012] Further, in S3), the gel matrix includes one or more of agarose, gelatin or polyvinyl alcohol; preferably, S3) includes: mixing, heating and cooling the tannic acid nanocarbon solution with the agarose solution to obtain a hydrogel; preferably, the concentration of the agarose solution is 1 to 5wt%; more preferably, the concentration of the agarose solution is 3wt%.

[0013] Furthermore, the diameter of the tannic acid nanocarbon is 20-100 nm; preferably, the pore size of the tannic acid nanocarbon hydrogel is 10-50 μm.

[0014] According to a third aspect of the present invention, a hydrogel containing tannic acid nano-carbon is provided. The hydrogel is prepared by any of the above-mentioned methods for preparing the hydrogel.

[0015] By applying the technical solution of the present invention, when a hydrogel containing tannic acid nanocarbon is used to prepare a preparation for promoting wound healing, because its active ingredient contains tannic acid nanocarbon, a preparation that promotes angiogenesis in chronic wounds of diabetic patients can be prepared, thereby accelerating the healing speed of such difficult-to-heal wounds. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 A schematic diagram of the characterization test results of tannic acid nanocarbon in Example 6 of the present invention is shown; wherein, Figure 1 Figure a is a schematic diagram of the ultraviolet absorption spectrum detection results; Figure 1 Middle b is a schematic diagram of the transmission electron microscope detection results;

[0018] Figure 2 A schematic diagram showing the characterization test results of tannic acid nanocarbon in Example 6 of the present invention is shown; Figure 2 Figure a is a schematic diagram of Fourier transform infrared absorption spectrum detection results; Figure 2 Fig. b shows a schematic diagram of the scanning electron microscope characterization test results of the tannic acid nanocarbon hydrogel in Example 6 of the present invention.

[0019] Figure 3 A general schematic diagram showing the changes in wound healing of mice in different treatment groups at 0, 3, 6, and 10 days in Example 7 of the present invention is shown.

[0020] Figure 4 A statistical diagram of wound area ratios of mice in different treatment groups on the 10th day in Example 7 of the present invention is shown.

[0021] Figure 5 A schematic diagram showing the results of CD31 immunohistochemical staining detection of mice in different treatment groups on the 10th day according to Example 7 of the present invention. DETAILED DESCRIPTION

[0022] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0023] As mentioned in the background technology, in the treatment of diabetic wounds with complex causes, microangiopathy caused by high blood sugar inhibits angiogenesis, which leads to prolonged and difficult healing of diabetic wounds. Therefore, promoting new blood vessel formation is crucial to improving the diabetic microenvironment and promoting wound healing, but there are few treatment options in the prior art that can promote the formation of new blood vessels in such wounds, which can provide a healing microenvironment for chronic diabetic wounds. Therefore, in this application, the inventor attempts to develop a new hydrogel containing tannic acid nanocarbon for promoting wound healing in diabetics, and thus proposes a series of protection schemes of this application.

[0024] In a first typical embodiment of the present application, a use of a hydrogel containing tannic acid nano-carbon in the preparation of a preparation for promoting wound healing is provided, wherein the active ingredient in the hydrogel includes tannic acid nano-carbon.

[0025] In the prior art, the dressings for treating common traumatic wounds usually focus on improving the antibacterial and antioxidant properties of the dressings. However, the wounds of diabetic patients are caused by multiple factors such as high blood sugar, bacterial infection, oxidative stress level and insufficient angiogenesis. In the prior art, the dressings for treating diabetic wounds include gauze dressings, foam dressings, film dressings, polymer gel dressings, and the preparation methods of such dressings include weaving, foaming, chemical cross-linking, dipping and coating, etc. If the dressings in the prior art are used for treatment, the effect is slow and needs to be replaced frequently. In addition, due to the particularity of diabetic wounds, the cost of the raw materials of such dressings is generally high, and the preparation process is complicated, which is not suitable for industrialized scale-up production.

[0026] Tannic acid is a natural polyphenol that can be extracted from a variety of plants (mainly oak and sumac). It has antioxidant, antibacterial, anti-inflammatory and biodegradable effects and can be used for the preparation of antibiotic-free antibacterial dressings. However, the benzene ring skeleton of tannic acid interacts with the polar end of the cell membrane phospholipid molecule to form a complex, which makes it difficult for it to enter the cell to exert its physiological activity. And when tannic acid is excessive, it will cause poisoning of the organism due to wound absorption, which is severely toxic to the liver, deepens the wound, and delays healing. Therefore, tannic acid is generally present as a reducing auxiliary material or carrier in wound dressings. In the prior art, a multifunctional mixed hydrogel containing tannic acid is usually prepared based on multiple components, with many steps, a complicated preparation method, and many added reagents, resulting in excessively high preparation costs.

[0027] In the present application, the inventors have found through a large number of studies that tannic acid is used as the main effective ingredient in the hydrogel and used as a carbon source. Tannic acid nanocarbon can be formed through a hydrothermal carbonization reaction, so that it has significant advantages such as good water solubility, biocompatibility and low toxicity, and can be used to prepare a hydrogel dressing that promotes wound healing in diabetic patients. In addition to the antibacterial properties of tannic acid itself, it also has a good ability to promote angiogenesis. The hydrogel containing tannic acid nanocarbon in the present application has simple raw materials and is formed by bonding tannic acid nanocarbon with a pharmaceutically acceptable hydrogel matrix (which can be selected from a pharmaceutically acceptable hydrogel matrix such as agarose, gelatin or polyvinyl alcohol), avoiding complex chemical addition regulation, having biosafety when used, and being able to promote angiogenesis at the wound of diabetic patients to accelerate the speed of wound healing.

[0028] In a preferred embodiment, promoting wound healing includes promoting angiogenesis at the wound; preferably, the wound includes difficult-to-heal wounds such as diabetic wounds and burn wounds; preferably, the dosage form of the preparation includes an external preparation; preferably, the external preparation includes an ointment, an ointment, a spray, a patch or a lotion.

[0029] In a preferred embodiment, the diameter of the tannic acid nanocarbon is 20-100 nm; preferably, the pore size of the tannic acid nanocarbon hydrogel is 10-50 μm.

[0030] The active ingredient tannic acid nanocarbon in the hydrogel containing tannic acid nanocarbon in the present application contains abundant oxygen-containing functional groups such as -OH, -C=O, OCO, and -CO, has a moderate diameter, and has good dispersibility in water. The tannic acid nanocarbon hydrogel prepared using this tannic acid nanocarbon has a rich pore structure with uniform pore size, which is conducive to locking water, maintaining a moist environment for the wound, and accelerating the wound healing speed by promoting angiogenesis in the wound of diabetic patients.

[0031] The wound healing preparation prepared by using the tannic acid nanocarbon hydrogel in the present application has a significant effect of promoting angiogenesis. Therefore, it can be applied to the preparation of dressings for diabetic wounds or other difficult-to-heal wounds (such as burn wounds, etc.). Since the dressing can promote the formation of blood vessels inside the wound, it can provide a healing microenvironment for the diabetic wound and accelerate the healing speed of the wound.

[0032] In a second typical embodiment of the present application, a method for preparing a hydrogel containing tannic acid nano-carbon in any of the above-mentioned applications is provided, and the preparation method comprises: S1) mixing tannic acid with water, heating and purifying to obtain tannic acid nano-carbon; S2) drying the tannic acid nano-carbon, and mixing it with a first solution to obtain a tannic acid nano-carbon solution; S3) mixing the tannic acid nano-carbon solution with a gel matrix, and heating to obtain the above-mentioned hydrogel.

[0033] Utilizing the preparation method in the present application, the prepared tannic acid nano-carbon has good dispersibility, and is uniform and stable, and a hydrogel containing tannic acid nano-carbon can be prepared by a simple one-step synthesis method. The hydrogel has excellent biocompatibility and is suitable for the preparation of dressings for repairing refractory wound tissues, such as dressings for chronic wounds and / or burn wounds of diabetics. Compared with the same type of dressings, the hydrogel in the present application can promote angiogenesis at the wound site and accelerate the healing of refractory wounds. In addition, the preparation method of the present application has simple steps, low raw material cost, and low reagent dosage, has biosafety, and is more suitable for industrialized scale-up production.

[0034] In a preferred embodiment, S1) includes: S11) mixing tannic acid with water to obtain a tannic acid solution; S12) dissolving the tannic acid in a reactor, heating and purifying to obtain tannic acid nano-carbon; preferably, the concentration of the tannic acid solution is 2 to 5wt%, including but not limited to 2wt%, 3wt%, 4wt% or 5wt%; preferably, the reactor includes a polytetrafluoroethylene reactor.

[0035] Hydrothermal carbonization refers to a process in which the heat and pressure in water are used to convert organic matter into carbonaceous materials under high temperature and / or high pressure conditions. The reaction does not require additional gas and catalyst, and the reaction time is relatively short. After tannic acid is mixed with water, it is placed in a polytetrafluoroethylene reactor for heating, and a hydrothermal carbonization reaction occurs. After purification and dialysis, tannic acid nanocarbon can be obtained. The preparation method is simple, and the tannic acid nanocarbon can be further prepared by reacting with a pharmaceutically acceptable hydrogel matrix to obtain a hydrogel, which is suitable for the preparation of dressings for the treatment of chronic wounds in diabetics.

[0036] In a preferred embodiment, purification comprises dialysis; preferably, the dialysis time is 36-72 hours, including but not limited to 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 55, 60, 65, 70, 71 or 72 hours.

[0037] The solution after the above reaction is purified by dialysis, which can remove most of the unreacted small molecules in the solution, so that the final tannic acid nanocarbon solution has a higher purity. After freezing and drying, tannic acid nanocarbon with good uniformity and dispersion can be obtained, which is more suitable for use in the subsequent preparation of tannic acid nanocarbon hydrogel to exert its ability to promote angiogenesis.

[0038] In a preferred embodiment, the heating temperature is 180-220°C, including but not limited to 180°C, 190°C, 200°C, 210°C or 200°C; preferably, the heating time is 8-12 hours, including but not limited to 8, 9, 10, 11 or 12 hours.

[0039] In a preferred embodiment, in S2), the concentration of the tannic acid nano-carbon solution is 0.1-2wt%, including but not limited to 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt% or 2wt%; preferably, the first solution comprises one or more of water, saline or phosphate buffer.

[0040] In a preferred embodiment, in S3), the gel matrix includes agarose, gelatin or polyvinyl alcohol; preferably, S3) includes: mixing the tannic acid nanocarbon solution with the agarose solution, heating, and cooling to obtain a hydrogel; preferably, the concentration of the agarose solution is 1 to 5wt%, including but not limited to 1wt%, 2wt%, 3wt%, 4wt% or 5wt%; more preferably, the concentration of the agarose solution is 3wt%.

[0041] In a preferred embodiment, the diameter of the tannic acid nanocarbon is 20-100 nm; preferably, the pore size of the tannic acid nanocarbon is 10-50 μm.

[0042] In a third typical embodiment of the present application, a hydrogel containing tannic acid nano-carbon is provided. The hydrogel is prepared by any of the above-mentioned methods for preparing a hydrogel containing tannic acid nano-carbon.

[0043] The beneficial effects of the present application will be further explained in detail below in conjunction with specific examples. The reagents and / or consumables used in the following examples are all commercially available products unless otherwise specified.

[0044] Example 1

[0045] Preparation of hydrogel containing tannic acid nanocarbon:

[0046] 1. Take 0.5 g of tannic acid and dissolve it in pure water to obtain a tannic acid solution with a mass concentration of 5 wt%.

[0047] 2. Place the tannic acid solution into a polytetrafluoroethylene reactor for hydrothermal carbonization reaction at a heating temperature of 200°C for 10 hours.

[0048] The reactor was naturally cooled to room temperature, the reaction solution was collected for dialysis purification, unreacted substances were removed by centrifugation and filtration, and tannic acid nanocarbon was obtained after freezing and drying.

[0049] The purification dialysis time was 48 hours.

[0050] 4. Take 0.1 g of tannic acid nanocarbon and mix it with 10 mL of water to prepare a tannic acid nanocarbon solution.

[0051] 5. Evenly mix the tannic acid nanocarbon solution and 3 wt % agarose solution, heat until dissolved, pour into a mold for gelation, and obtain tannic acid nanocarbon hydrogel.

[0052] Example 2

[0053] The difference from Example 1 is that the mass concentration of the tannic acid solution in step 1 of this embodiment is 2wt%, the mass concentration of the tannic acid nano-carbon solution in step 4 is 1wt%, and the purification dialysis time is 72h. The remaining steps are consistent with those in Example 1.

[0054] Example 3

[0055] The difference from Example 1 is that the mass concentration of the tannic acid solution in step 1 of this embodiment is 4wt%, the mass concentration of the tannic acid nano-carbon solution in step 4 is 0.5wt%, and the purification dialysis time is 36h. The remaining steps are consistent with those in Example 1.

[0056] Example 4

[0057] The difference from Example 1 is that the mass concentration of the tannic acid solution in step 1 of this embodiment is 10wt%. The mass concentration of the tannic acid nano-carbon solution in step 4 is 4wt%, and the purification dialysis time is 96h. The remaining steps are consistent with those in Example 1.

[0058] Example 5

[0059] The difference from Example 1 is that the mass concentration of tannic acid in step 1 of this embodiment is 1wt%. The mass concentration of tannic acid nano-carbon solution in step 4 is 0.05wt%, and the purification dialysis time is 24h. The remaining steps are consistent with those in Example 1.

[0060] Example 6

[0061] The tannic acid nanocarbon hydrogels prepared in Examples 1-5 were characterized and tested.

[0062] The detection methods include: UV-visible spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy.

[0063] UV-visible spectroscopy: Through the absorption peak of tannic acid nanocarbon between 200-600nm, observe whether it has an ultraviolet absorption peak in the 200-220nm region to determine whether tannic acid nanocarbon can be successfully synthesized using the preparation method of the present application.

[0064] Transmission electron microscopy observation method: The prepared tannic acid nanocarbon is placed under a transmission electron microscope to observe its morphology and measure its diameter.

[0065] Fourier transform infrared spectroscopy: Different functional groups have different transmittances at different wavelengths. The tannic acid nanocarbons prepared in different embodiments were evaluated at 400-4000 cm -1 The transmittance is used to analyze the status of oxygen-containing functional groups (including -OH, -C=O, OCO, and -CO).

[0066] Scanning electron microscopy: The freeze-dried tannic acid nanocarbon hydrogels of Examples 1-5 were placed under a scanning electron microscope to observe their pore structures and count the pore sizes.

[0067] The characterization data after detection by the above detection method show that the diameter of the tannic acid nanocarbon prepared in the examples of the present application is between 20-100nm, contains a large number of oxygen-containing functional groups, and can be dispersed in water; among them, the tannic acid nanocarbon hydrogel prepared in Examples 1, 2 and 3 has a pore size between 10-50μm, rich pore structure, and good uniformity and dispersibility. The characterization performance of the tannic acid nanocarbon and tannic acid nanocarbon hydrogel prepared in Examples 4 and 5 shows that their uniformity and dispersibility are poorer than those in Examples 1, 2 and 3.

[0068] The characterization test results of tannic acid nanocarbon in Example 1 are shown in FIG. Figure 1 He Ru Figure 2 As shown, Figure 1 Figure a is the result of ultraviolet absorption spectrum detection; Figure 1 Figure b is the transmission electron microscope test result; Figure 2 Figure a is the Fourier transform infrared absorption spectrum test result, and “TANCs” stands for “tannic acid nanocarbon”; Figure 2 Figure b is a schematic diagram of the scanning electron microscopy characterization results of tannic acid nanocarbon hydrogel.

[0069] Example 7

[0070] The tannic acid nanocarbon hydrogel prepared in Example 1, the blank hydrogel without tannic acid nanocarbon, and the silver-doped tannic acid nanocarbon hydrogel were used to treat the wounds of diabetic mice. The wound healing changes of the mice were observed and recorded from 1 to 10 days. CD31 immunohistochemical staining was performed on the 10th day to detect the angiogenesis in the skin wound area of ​​the mice. The grouping is shown in Table 1.

[0071] Among them, the method for preparing a blank hydrogel without tannic acid nanocarbon is as follows: an agarose solution is introduced into a mold for gelation to obtain a blank hydrogel without tannic acid nanocarbon.

[0072] The steps of preparing silver-doped tannic acid nanocarbon hydrogel are as follows, and the reaction conditions are the same as those in Example 1:

[0073] 1. Under stirring conditions, dissolve 0.5 g of tannic acid in 10 mL of pure water to obtain a tannic acid solution.

[0074] 2. Under stirring conditions, add 0.01 g of silver nitrate to the tannic acid solution in step 1 for coordination to obtain a mixed solution.

[0075] 3. Place the mixed solution obtained in step 2 into a polytetrafluoroethylene reactor and perform a hydrothermal carbonization reaction in a muffle furnace;

[0076] 4. After the reactor is naturally cooled to room temperature, the reaction solution in step 3 is collected and dialyzed and centrifuged to remove impurities;

[0077] 5. Collect the solution in step 4 and perform vacuum freeze drying to obtain silver-doped tannic acid nano-carbon powder;

[0078] 6. Prepare a solution from the powder obtained in step 5, mix it evenly with 3 wt % agarose solution and heat it until dissolved, then pour it into a silica gel mold for gelation to prepare a hydrogel patch.

[0079] Table 1

[0080] Group Mouse type Hydrogels for wound care Control group Non-diabetic mice Blank hydrogel without tannic acid nanocarbon 1 Diabetic mice Blank hydrogel without tannic acid nanocarbon 2 Diabetic mice Tannic acid nanocarbon hydrogel 3 Diabetic mice Silver-doped tannic acid nanocarbon hydrogel

[0081] The screening criteria for diabetic mice in this example were as follows: male (C57BL / 6J) mice, 35 days old, were selected and a diabetic animal model was established by chemical induction (blood was collected from the tail 3, 7, and 14 days after intraperitoneal injection of STA to measure random blood glucose). The mice were enrolled if their blood glucose was higher than 16.7 mmol / L for three times and accompanied by symptoms of "three mores and one less" (more drinking, more eating, more urination, and weight loss). A total of 18 mice that met the inclusion criteria were selected.

[0082] Non-diabetic mice: Male (C57BL / 6J) mice, 35 days old, were selected and injected with the same dose of sodium citrate solution as the diabetic mice at the same time of STA induction to prepare the control group of mice.

[0083] Wound formation in diabetic mice and normal mice: Diabetic mice (18 mice, divided into 3 groups) and control group mice (6 mice injected with the same dose of sodium citrate solution) were anesthetized with 0.1% sodium pentobarbital, and the dorsal area of ​​the rats was depilated, the skin was wiped and disinfected with 75% alcohol, and a circular wound with a diameter of 1 cm was formed in the middle of the mouse's back with a skin biopsy device with a diameter of 1 cm, and the excision range reached the depth of the fascia.

[0084] The wounds of the control group mice (non-diabetic mice) and the diabetic mice in group 1 were treated with blank hydrogels without tannic acid nanocarbon, and the wounds of the diabetic mice in groups 2 and 3 were treated with the tannic acid nanocarbon hydrogel prepared in Example 1 and the silver-doped tannic acid nanocarbon hydrogel, respectively. The wounds were changed every 2 days, and the wound healing of mice in different groups was observed at different times. The wound healing results of the wounds of mice in different groups on the 0th, 3rd, 6th and 10th days after being treated with different hydrogels are shown in the figure below. Figure 3 shown.

[0085] Image J software was used to evaluate the wound healing status of mice in different groups by the ratio of the remaining wound area to the original wound area on the 10th day. The final calculation results were as follows: Figure 4 shown.

[0086] CD31 immunohistochemical staining was used to detect angiogenesis in mice. CD31 is also known as platelet endothelial cell adhesion molecule-1 and is mainly expressed in endothelial cells. CD31 immunohistochemical staining is used to detect the expression level of CD31 in the wound area, and the angiogenesis is judged based on the staining intensity and distribution of CD31.

[0087] The detection method includes: on the 10th day of treatment, skin tissues from the original wound area of ​​mice in different groups were cut and fixed with 4% paraformaldehyde; after dehydration, embedding and sectioning, dewaxing and hydration were performed; 3% hydrogen peroxide was used to remove endogenous peroxidase, and microwave antigen repair and blocking were performed; CD31 primary and secondary antibodies were used for incubation, and DAB color was used for dehydration, transparency and sealing. The distribution of CD31 positive new blood vessels in the wound area was observed under a microscope. The results are as follows Figure 5 As shown, arrows point to the sites of neovascularization.

[0088] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: the hydrogel containing tannic acid nanocarbon in the present application has simple and easy-to-obtain raw materials, a simple preparation method, and can be used in the preparation of preparations that promote wound healing, can exert the antibacterial properties of tannic acid itself, and can also promote the formation of blood vessels in chronic wounds with complex causes and difficult to heal, thereby accelerating the speed of wound healing. In addition, compared with the same type of preparations in the prior art, it has lower cost and is suitable for industrialized amplification production.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Application of a hydrogel containing tannic acid nanocarbon in the preparation of a preparation for promoting wound healing, characterized in that: The active ingredient in the hydrogel is the tannic acid nanocarbon; The promoting wound healing comprises promoting angiogenesis at the wound site; The dosage forms of the preparation include external preparations; The topical preparation includes one or more of a liniment, an ointment, a spray, a patch or a lotion; The diameter of the tannic acid nanocarbon is 20-100 nm; The pore size of the tannic acid nanocarbon hydrogel is 10-50 μm; The gel matrix in the hydrogel includes one or more of agarose, gelatin or polyvinyl alcohol; The wound is a wound of a diabetic patient.

2. The method for preparing the hydrogel in the application of claim 1, characterized in that: The preparation method comprises: S1) mixing tannic acid with water and heating the mixture to obtain tannic acid nanocarbon; S2) drying the tannic acid nano-carbon and mixing it with the first solution to obtain a tannic acid nano-carbon solution; S3) mixing the tannic acid nano-carbon solution with a gel matrix to obtain the hydrogel; The gel matrix includes one or more of agarose, gelatin or polyvinyl alcohol; Said S1) includes: S11) mixing the tannic acid with water to obtain a tannic acid solution; S12) placing the tannic acid solution in a reaction kettle, heating it, and purifying it to obtain the tannic acid nano-carbon; The concentration of the tannic acid solution is 2-5 wt %; The reactor comprises a polytetrafluoroethylene reactor; The first solution includes one or more of water, physiological saline or phosphate buffer.

3. The preparation method according to claim 2, characterized in that: The purification includes dialysis.

4. The preparation method according to claim 3, characterized in that: The dialysis time is 36-72 hours.

5. The preparation method according to claim 2, characterized in that: The heating temperature is 180-220°C.

6. The preparation method according to claim 2, characterized in that: The heating time is 8-12 hours.

7. The preparation method according to claim 2, characterized in that: In the S2), the concentration of the tannic acid nano-carbon solution is 0.1-2 wt%.

8. The preparation method according to claim 2, characterized in that: The S3) comprises: mixing the tannic acid nanocarbon solution and the agarose solution, heating, and cooling to obtain the hydrogel.

9. The preparation method according to claim 8, characterized in that: The concentration of the agarose solution is 1-5wt%.

10. The preparation method according to claim 9, characterized in that: The concentration of the agarose solution is 3wt%.

11. The preparation method according to claim 2, characterized in that: The diameter of the tannic acid nanocarbon is 20-100 nm.

12. The preparation method according to claim 2, characterized in that: The pore size of the tannic acid nanocarbon hydrogel is 10-50 μm.

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