A hydrogel dressing that promotes wound healing

Abstract

This invention discloses a hydrogel dressing that promotes wound healing. The hydrogel dressing of this invention comprises 1-15 parts by weight of polyvinyl alcohol, 0.3-10 parts by weight of tannic acid, 0.1-10 parts by weight of borax, 0.1-10 parts by weight of Fan's recombinant collagen, and the balance being water (based on 100 parts by weight of the hydrogel dressing), wherein the weight ratio of borax to tannic acid is 1:3 or higher. This invention provides an adaptive polyvinyl alcohol hydrogel dressing in which Fan's recombinant collagen and tannic acid can coexist and function synergistically.

Description

Technical Field

[0001] This technology relates to the field of biomedical materials technology, specifically to a polyvinyl alcohol hydrogel dressing that can promote wound healing. Background Technology

[0002] Polyvinyl alcohol hydrogel is often used as a matrix material for wound dressings. However, wound dressings based on polyvinyl alcohol hydrogel tend to have a fixed shape and lack adaptability. They can only cover the surface of the wound and cannot be used for deep or irregular wounds. It should be noted that the adaptability of hydrogel materials refers to the fact that the hydrogel is at the fluid-gel inflection point, and its shape can spontaneously change to adapt to external conditions, such as irregular or deep and complex wounds.

[0003] Tannic acid is a weakly acidic polyphenol compound with strong adhesive properties, particularly enhancing cell adhesion and proliferation. This high adhesiveness is attributed to its active catechol groups, which promote cell adhesion by binding to reactive groups (amino, carboxyl, and catechol groups) on the cell membrane. Tannic acid also possesses excellent antioxidant, antibacterial, anti-inflammatory, and hemostatic properties, as well as good biodegradability. Tannic acid has been incorporated into polyvinyl alcohol hydrogels to prepare tannic acid-containing polyvinyl alcohol hydrogel medical dressings.

[0004] Fan's recombinant collagen, invented by Professor Fan Daidi of Northwest University in China (see Chinese Patent Application Publication CN1371919A), possesses a triple-strand, triple-helix structure and is a highly biocompatible recombinant collagen. Fan's recombinant collagen can promote cell growth, provide nutrients to cells, promote the proliferation of skin fibroblasts, and enhance collagen expression in skin tissue, thus exhibiting excellent wound-healing properties and is currently widely used in the medical and cosmetic fields. Researchers have long hoped to simultaneously incorporate tannic acid and Fan's recombinant collagen into polyvinyl alcohol hydrogels and endow them with adaptability, thereby enabling them to exert multiple functions (adaptability, antioxidant, antibacterial, anti-inflammatory, and hemostatic properties, promoting wound healing) to prepare higher-performance polyvinyl alcohol hydrogel medical dressings.

[0005] However, the researchers' expectations were not met for at least the following reasons: 1. In the existing technology, regardless of the method used to prepare polyvinyl alcohol hydrogels containing tannic acid, the gel fraction is very low, meaning that a large amount of water is discharged from the system during the preparation process, resulting in hydrogels with low water content and hard texture, let alone adaptive properties; 2. Tannic acid can cause the aggregation of Fan's recombinant collagen molecules, leading to precipitation, which prevents the two from coexisting effectively in the polyvinyl alcohol hydrogel system and from performing their functions together. Summary of the Invention

[0006] In view of the above-mentioned technical problems existing in the prior art, the purpose of the present invention is to provide an adaptive polyvinyl alcohol hydrogel dressing in which recombinant collagen and tannic acid can coexist and function together.

[0007] Through in-depth research, the inventors discovered that by adding a certain amount of borax (with a borax to tannic acid weight ratio of 1:3 or higher) to a polyvinyl alcohol hydrogel containing recombinant collagen and tannic acid, the recombinant collagen and tannic acid can stably coexist in the polyvinyl alcohol hydrogel system and function together. Furthermore, such a polyvinyl alcohol hydrogel also possesses self-adaptive properties. Moreover, borax provides an ion conductor, endowing the polyvinyl alcohol hydrogel with electrical conductivity, allowing the polyvinyl alcohol hydrogel dressing of this invention to be used in conjunction with electrostimulation therapy to achieve better wound healing effects.

[0008] That is, the present invention includes:

[0009] 1. A hydrogel dressing, comprising, per 100 parts by weight:

[0010]

[0011] The weight ratio of borax to tannic acid is 1:3 or higher.

[0012] The upper limit for the weight ratio of borax to tannic acid can be 5:1, 3:1, 2:1, or 1:1. Optionally, the hydrogel dressing of the present invention may or may not contain other ingredients.

[0013] Preferably, the lower limit of the weight ratio of borax to polyvinyl alcohol can be, for example, 1:10 or 1:8, and the upper limit can be, for example, 1:3 or 1:5.

[0014] 2. The aforementioned hydrogel dressing, wherein the polyvinyl alcohol is 2 to 10 parts by weight, preferably 5 to 10 parts by weight.

[0015] 3. The aforementioned hydrogel dressing, wherein the tannic acid is 0.5 to 5 parts by weight, preferably 1 to 3 parts by weight.

[0016] 4. The aforementioned hydrogel dressing, wherein the borax is 0.2 to 5 parts by weight, preferably 0.5 to 3 parts by weight.

[0017] 5. The aforementioned hydrogel dressing, wherein the Fan's recombinant collagen is 0.5 to 5 parts by weight, preferably 1 to 2 parts by weight.

[0018] 6. The aforementioned hydrogel dressing, wherein the polyvinyl alcohol has a weight-average molecular weight of 89,000-98,000 Da and a degree of hydrolysis greater than 99%.

[0019] 7. The aforementioned hydrogel dressing is used to promote wound healing.

[0020] 8. The method for preparing the hydrogel dressing according to item 1, comprising the following steps:

[0021] 5) Prepare a polyvinyl alcohol solution of a certain concentration (e.g., 3-17% by weight);

[0022] 6) Prepare a borax solution of a certain concentration (e.g., 1-5% by weight);

[0023] 7) Prepare a tannic acid solution of a certain concentration (e.g., 1-20% by weight);

[0024] 8) Prepare a solution of Fan's recombinant collagen at a certain concentration (e.g., 1-15% by weight);

[0025] Take the borax solution prepared in step 2) and the tannic acid solution prepared in step 3) and mix them evenly. Then add the Fan's recombinant collagen solution prepared in step 4) to obtain solution A. Take an appropriate amount of solution A and add it to the polyvinyl alcohol solution prepared in step 1). Add a certain amount of water as needed, stir well, and let it stand at room temperature for a certain period of time (e.g., 24 hours) to obtain the hydrogel dressing described in item 1; or,

[0026] Mix the borax solution prepared in step 2) with the Fan's recombinant collagen solution prepared in step 4) until homogeneous, then add the tannic acid solution prepared in step 3) to obtain solution B. Add an appropriate amount of solution B to the polyvinyl alcohol solution prepared in step 1), and add a certain amount of water as needed. Stir well and allow to stand at room temperature for a certain period of time (e.g., 24 hours) to swell, thus obtaining the hydrogel dressing described in item 1; or...

[0027] Mix the polyvinyl alcohol solution prepared in step 1) with the recombinant collagen solution prepared in step 4) to obtain solution C. Mix the borax solution prepared in step 2) with the tannic acid solution prepared in step 3) evenly to obtain solution D. Finally, mix solution C and solution D, and add a certain amount of water as needed. After stirring, let it stand at room temperature for a certain period of time (e.g., 24 hours) to obtain the hydrogel dressing described in item 1.

[0028] 9. The aforementioned hydrogel dressing is used in the preparation of hydrogel dressings that promote wound healing. The aforementioned hydrogel dressing is an adaptive, conductive, self-healing, antibacterial, and anti-inflammatory hydrogel dressing. It possesses self-healing, adaptive, and conductive properties, a free radical scavenging rate of over 80%, and an inhibition rate of over 90% against Staphylococcus aureus and Escherichia coli. It exhibits excellent wound hemostasis and repair effects as well as anti-inflammatory properties.

[0029] 10. The aforementioned uses, wherein the wound-healing hydrogel dressing is used in combination with electrostimulation therapy. The aforementioned hydrogel dressing is an adaptive conductive hydrogel that can be used in combination with electrostimulation therapy to repair wounds and promote wound healing. Its mechanisms of action include: downregulating inflammation, antibacterial activity, increasing tissue oxygenation, reducing wound blood flow, promoting angiogenesis, and promoting fibroblast proliferation. Attached Figure Description

[0030] Figure 1 Graphs showing the morphology of the hydrogels of Examples 1-4 and Comparative Examples 1-3.

[0031] Figure 2 The figures illustrate feasible and infeasible preparation methods for the hydrogel of the present invention.

[0032] Figure 3 The figure shows the appearance and self-healing properties of the hydrogel in Example 5.

[0033] Figure 4 A diagram illustrating the internal bonding of the hydrogel in Example 5.

[0034] Figure 5 A graph illustrating the adaptability of the hydrogel in Example 5.

[0035] Figure 6 A graph illustrating the conductivity of the hydrogel in Example 5.

[0036] Figure 7 A graph showing the antioxidant properties of the hydrogel in Example 5.

[0037] Figure 8 A graph illustrating the antibacterial properties of the hydrogel in Example 5.

[0038] Figure 9 A graph showing the liver hemostatic properties of the hydrogel of Example 5.

[0039] Figure 10 A graph showing the anti-inflammatory properties (IL-6 level) of the hydrogel of Example 5.

[0040] Figure 11 A graph illustrating the full-thickness skin wound repair performance of the hydrogel of Example 5.

[0041] Figure 12 A diagram illustrating the mechanism of hemostasis and repair of deep wounds by adaptive conductive hydrogel.

[0042] Figure 13 Graphs showing the gelation state and gel fraction of the hydrogels of Examples 1-4 and Comparative Examples 1-3. Detailed Implementation

[0043] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0044] As an embodiment of the present invention, the polyvinyl alcohol has a weight-average molecular weight of 89,000-98,000 Da and a degree of alcoholysis greater than 99%. The molecular weight of Fan's recombinant collagen is 96,000 Da. The molecular weight of tannic acid is 1,700 Da.

[0045] Gel fraction = Weight of the hydrogel produced / Total weight of the materials added

[0046] Comparative Example 1

[0047] 1) Weigh out polyvinyl alcohol and dissolve it in deionized water. Heat the solution to 90°C until it is completely dissolved, and prepare a 10% PVA solution by weight.

[0048] 2) Weigh out tannic acid and dissolve it in deionized water. Sonicate the solution until it is completely dissolved to prepare a 4% by weight solution.

[0049] 3) Weigh out the human-like collagen and dissolve it in deionized water. Dissolve it in a constant temperature water bath at 37°C to prepare an 8% by weight solution.

[0050] 4) Scheme ①: Add 10 parts by weight of the tannic acid solution prepared in step 2) to 10 parts by weight of the Fan's recombinant collagen solution prepared in step 3) to obtain solution A. Add solution A to 50 parts by weight of the polyvinyl alcohol solution prepared in step 1), and then add 30 parts by weight of water. After stirring, let it stand at room temperature for 24 hours to swell, and you will get the hydrogel of Comparative Example 1.

[0051] The gel fraction of the hydrogel in Comparative Example 1 was determined to be 2.8%, and the resulting hydrogel was hard and lacked self-adaptability. Observation revealed that a large amount of aqueous liquid was still present in the system.

[0052] Comparative Example 2

[0053] 1) Weigh out polyvinyl alcohol and dissolve it in deionized water. Heat the solution to 90°C until it is completely dissolved, and prepare a 10% PVA solution by weight.

[0054] 2) Weigh out borax and dissolve it in deionized water, sonicate it until completely dissolved, and prepare a 0.167% by weight solution.

[0055] 3) Weigh out tannic acid and dissolve it in deionized water. Sonicate the solution until it is completely dissolved to prepare a 4% by weight solution.

[0056] 4) Weigh out the human-like collagen and dissolve it in deionized water. Dissolve it in a constant temperature water bath at 37°C to prepare an 8% by weight solution.

[0057] 5) Take 30 parts by weight of the borax solution prepared in step 2) and mix it evenly with 10 parts by weight of the tannic acid solution prepared in step 3). Then add 10 parts by weight of the Fan's recombinant collagen solution prepared in step 4) to obtain solution A. Add solution A to 50 parts by weight of the polyvinyl alcohol solution prepared in step 1). Stir well and let it stand at room temperature for 24 hours to swell, thus obtaining the hydrogel of Comparative Example 2.

[0058] The gel fraction of the hydrogel in Comparative Example 2 was determined to be 1.9%, and the resulting hydrogel was hard and lacked self-adaptability. Observation revealed that a large amount of viscous liquid was still present in the system.

[0059] Comparative Example 3

[0060] 1) Weigh out polyvinyl alcohol and dissolve it in deionized water. Heat the solution to 90°C until it is completely dissolved, and prepare a 10% PVA solution by weight.

[0061] 2) Weigh out borax and dissolve it in deionized water, then sonicate it until completely dissolved to prepare a 2.67% by weight solution.

[0062] 3) Weigh out tannic acid and dissolve it in deionized water (40℃), sonicate it until completely dissolved, and prepare a 32% by weight solution.

[0063] 4) Weigh out the human-like collagen and dissolve it in deionized water. Dissolve it in a constant temperature water bath at 37°C to prepare an 8% by weight solution.

[0064] 5) Mix 30 parts by weight of the borax solution prepared in step 2) with 10 parts by weight of the Fan's recombinant collagen solution prepared in step 4) until homogeneous, then add 10 parts by weight of the tannic acid solution prepared in step 3) to obtain solution B. Add solution B to 50 parts by weight of the polyvinyl alcohol solution prepared in step 1), stir well, and let it stand at room temperature for 24 hours to swell, thus obtaining the hydrogel of Comparative Example 3.

[0065] Observations show that a mixture of two hydrogels was actually formed in the system, one with a hard texture and the other with a soft texture, resulting in an uneven system.

[0066] Example 1

[0067] 1) Weigh out polyvinyl alcohol and dissolve it in deionized water. Heat the solution to 90°C until it is completely dissolved, and prepare a 10% PVA solution by weight.

[0068] 2) Weigh out borax and dissolve it in deionized water. Sonicate the solution until it is completely dissolved to prepare a 2.67% by weight solution.

[0069] 3) Weigh out tannic acid and dissolve it in deionized water. Sonicate the solution until it is completely dissolved to prepare an 8% by weight solution.

[0070] 4) Weigh out the human-like collagen and dissolve it in deionized water. Dissolve it in a constant temperature water bath at 37°C to prepare an 8% by weight solution.

[0071] 5) Mix 30 parts by weight of the borax solution prepared in step 2) with 10 parts by weight of the Fan's recombinant collagen solution prepared in step 4), and then add 10 parts by weight of the tannic acid solution prepared in step 3) to obtain solution B. Add solution B to 50 parts by weight of the polyvinyl alcohol solution prepared in step 1), stir well, and allow to stand at room temperature for 24 hours to swell, thus obtaining the hydrogel of Example 1. The gel fraction was determined to be greater than 90%.

[0072] Example 2

[0073] 1) Weigh out polyvinyl alcohol and dissolve it in deionized water. Heat the solution to 90°C until it is completely dissolved, and prepare a 10% PVA solution by weight.

[0074] 2) Weigh out borax and dissolve it in deionized water. Sonicate the solution until it is completely dissolved to prepare a 2.67% by weight solution.

[0075] 3) Weigh out tannic acid and dissolve it in deionized water. Sonicate the solution until it is completely dissolved to prepare a 16% by weight solution.

[0076] 4) Weigh out the human-like collagen and dissolve it in deionized water. Dissolve it in a constant temperature water bath at 37°C to prepare an 8% by weight solution.

[0077] 5) Mix 50 parts by weight of the polyvinyl alcohol solution prepared in step 1) with 10 parts by weight of the Fan's recombinant collagen solution prepared in step 4) to obtain solution C. Mix 30 parts by weight of the borax solution prepared in step 2) with 10 parts by weight of the tannic acid solution prepared in step 3) to obtain solution D. Finally, mix solutions C and D, stir well, and allow to stand at room temperature for 24 hours to swell, thus obtaining the hydrogel of Example 2. The gel fraction was determined to be greater than 90%.

[0078] Example 3

[0079] 1) Weigh out polyvinyl alcohol and dissolve it in deionized water. Heat the solution to 90°C until it is completely dissolved, and prepare a 10% PVA solution by weight.

[0080] 2) Weigh out borax and dissolve it in deionized water. Sonicate the solution until it is completely dissolved to prepare a 2.67% by weight solution.

[0081] 3) Weigh out tannic acid and dissolve it in deionized water. Sonicate the solution until it is completely dissolved to prepare a 24% by weight solution.

[0082] 4) Weigh out the human-like collagen and dissolve it in deionized water. Dissolve it in a constant temperature water bath at 37°C to prepare an 8% by weight solution.

[0083] 5) Mix 30 parts by weight of the borax solution prepared in step 2) with 10 parts by weight of the tannic acid solution prepared in step 3) until homogeneous, then add 10 parts by weight of the Fan's recombinant collagen solution prepared in step 4) to obtain solution A. Add solution A to 50 parts by weight of the polyvinyl alcohol solution prepared in step 1), stir well, and allow to stand at room temperature for 24 hours to swell, thus obtaining the hydrogel of Example 3. The gel fraction was determined to be greater than 90%.

[0084] Example 4

[0085] 1) Weigh out polyvinyl alcohol and dissolve it in deionized water. Heat the solution to 90°C until it is completely dissolved, and prepare a 10% PVA solution by weight.

[0086] 2) Weigh out borax and dissolve it in deionized water. Sonicate the solution until it is completely dissolved to prepare a 5.52% by weight solution.

[0087] 3) Weigh out tannic acid and dissolve it in deionized water (40℃), sonicate it until completely dissolved, and prepare a 32% by weight solution.

[0088] 4) Weigh out the human-like collagen and dissolve it in deionized water. Dissolve it in a constant temperature water bath at 37°C to prepare an 8% by weight solution.

[0089] 5) Mix 30 parts by weight of the borax solution prepared in step 2) with 10 parts by weight of the Fan's recombinant collagen solution prepared in step 4), and then add 10 parts by weight of the tannic acid solution prepared in step 3) to obtain solution B. Add solution B to 50 parts by weight of the polyvinyl alcohol solution prepared in step 1), stir well, and let it stand at room temperature for 24 hours to swell, thus obtaining the hydrogel of Example 4. The gel fraction was determined to be greater than 90%.

[0090] Figure 1 and Figure 13 The images show actual photographs of the hydrogels prepared in Examples 1-4 and Comparative Examples 1-3. It can be seen that the hydrogels in Examples 1-4 did not produce any precipitation and were homogeneous, while the hydrogels in Comparative Examples 1-3 produced precipitation and were not homogeneous. Furthermore, the adaptive properties of the hydrogels prepared in Examples 1-4 and Comparative Examples 1 and 2 were measured as in item (3) of Example 5 below. The results show that the hydrogels in Examples 1-4 possess adaptive properties, while the hydrogels in Comparative Examples 1 and 2 do not. The adaptive properties of the hydrogel in Comparative Example 3 could not be measured because it was not a homogeneous system.

[0091] Furthermore, through extensive experimental research, the inventors discovered that in the preparation of the hydrogel of this invention, the contact between polyvinyl alcohol and tannic acid must be carried out in the presence of borax; otherwise, flocculent matter will appear in the prepared hydrogel (which is irreversible even with the addition of borax), resulting in an inhomogeneous system. Figure 2 ).

[0092] Example 5

[0093] The preparation method of the hydrogel in this embodiment includes the following steps:

[0094] To prepare 100 parts by weight of hydrogel

[0095] 1) Weigh out polyvinyl alcohol and dissolve it in deionized water. Heat the solution to 90°C until it is completely dissolved, and prepare a 10% PVA solution by weight.

[0096] 2) Weigh out borax and dissolve it in deionized water, sonicate it until completely dissolved, and prepare a 3% by weight solution.

[0097] 3) Weigh out tannic acid and dissolve it in deionized water. Sonicate the solution until it is completely dissolved to prepare a 10% by weight solution.

[0098] 4) Weigh out the human-like collagen and dissolve it in deionized water. Dissolve it in a constant temperature water bath at 37°C to prepare a 10% by weight solution.

[0099] 5) Take 30 parts by weight of the borax solution prepared in step 2) and mix it evenly with 10 parts by weight of the tannic acid solution prepared in step 3). Then add 10 parts by weight of the Fan's recombinant collagen solution prepared in step 4) to obtain solution A. Add solution A to 50 parts by weight of the polyvinyl alcohol solution prepared in step 1). Stir well and let it stand at room temperature for 24 hours to swell, and you will get the hydrogel of Example 5.

[0100] The performance of the hydrogel prepared in Example 5 of this invention was tested and explained.

[0101] (1) Appearance and self-healing properties: The hydrogel in Example 5 appeared pale yellow. Its self-healing properties were as follows... Figure 3 As shown, after staining the hydrogel of Example 5 with Rhodamine B and Alcin Blue respectively, placing two hydrogels of different colors together, they self-healed within 30 seconds without external force. The self-repair mechanism is due to the formation of dynamic borate ester bonds between the hydroxyl groups of PVA (or TA) and the borate. Once contact occurs, the dynamic bonds can be rebuilt at the interface between the two hydrogels. The resulting hydrogel can be stretched and the contact portion can completely merge because there are sufficient free hydroxyl groups and borate on the surface of the hydrogel, which can establish borate ester bonds and hydrogen bonds at the contact interface.

[0102] (2) Crosslinking mechanism of the internal network of hydrogel: Figure 4 In pure PVA (a), characteristic peaks show that the tensile vibration peak of the -OH group is at 3300 cm⁻¹. -1 At this point, the tensile vibration peak of the -CH alkyl group is between 2940 and 2905 cm⁻¹. -1The stretching vibration peak of the -CO secondary alcohol is at 1086 cm⁻¹. -1 A symmetrical C-C tensile vibration peak was observed at 1142 cm⁻¹. -1 This is characteristic of semi-crystalline PVA. The characteristic peak for the formation of borate ester bonds in the condensation reaction of PVA with boric acid is at 1430 cm⁻¹. -1 and 1337cm -1 The peak at 1123 cm⁻¹ is due to BOC asymmetric stretch relaxation. -1 and 1129cm -1 The peak at 1094 cm⁻¹ represents the BOC tensile vibration. Meanwhile, the PVA main chain peaks at 1094 cm⁻¹. -1 The characteristic absorption at the point (corresponding to the stretching vibration of COC) disappears in the PVA-boronic acid binding spectrum, indicating that the PVA-boronic acid condensation reaction forms a borate ester bond. Figure 4 In b, at 1429cm -1 and 1334cm -1 The peak at 1284 cm⁻¹ represents the asymmetric stretching relaxation of B–O–C, while the peak at 1284 cm⁻¹ represents the asymmetric stretching relaxation of B–O–C. -1 1196cm -1 and 1130cm -1 The peak at that point is due to the tensile vibration of BOC. The results indicate that the crosslinking between TA and borax forms borate ester coordination bonds. Figure 4 In c, the characteristic peak of TA is 3600-3100 cm⁻¹. -1 The broadband range is due to the extension of the phenolic hydroxyl groups in TA. The characteristic peak of the C=O bond in HLC is at 1637 cm⁻¹. -1 At this point, the absorption peak of the aromatic C=O bond of TA is at 1611 cm⁻¹. -1 At this location, after HLC and TA bind, it is only at 1628 cm⁻¹. -1 A peak was observed, indicating that the two types of C=O bonds overlapped, and hydrogen bonds exist between HLC and TA. The connection between PVA and TA is as follows. Figure 4 As shown in d: the peak of the -OH stretching vibration of PVA shifts, becoming shorter and broader; the peak of the main stretching vibration of CH shifts relatively due to hydrogen bonding crosslinking (2942.2 cm⁻¹). -1 →2908.91cm -1 1661.71cm -1 →1606.25cm -1 1331.84cm -1 →1315.92cm -1 678.73cm -1 →505.91cm -1 This indicates that hydrogen bonding exists between PVA and TA. The connection mechanism between PVA and HLC is as follows: Figure 4 As shown in Figure e, the characteristic peak of the -OH tensile vibration of PVA is 3314 cm⁻¹.-1 The bending vibration peaks of CH-OH (1450 cm⁻¹) and CH-OH -1 The relative displacement of all molecules indicates the presence of hydrogen bonds between them.

[0103] (3) Adaptive performance: such as Figure 5 As shown, in Example 5, the hydrogel can move along the natural forces of gravity and surface tension. A glass sphere with a diameter of 8 mm is placed in a beaker, and the hydrogel is placed on the surface of the glass sphere. The hydrogel slowly moves downward (under the action of gravity) and engulfs the glass sphere after 8 minutes, eventually completely filling the narrow space around the bead, demonstrating its self-movement.

[0104] (4) Electrical conductivity: such as Figure 6 As shown, the hydrogel in Example 5 can light up an LED, indicating that the hydrogel has high electrical conductivity. The conductivity of the hydrogel can be measured using a Tektronix DMM6500 instrument, demonstrating that the hydrogel has excellent electrical conductivity.

[0105] (5) Antioxidant properties: Free radicals play a crucial role in all stages of wound healing. Topical application of free radical scavenging materials has been shown to accelerate wound repair. For example... Figure 7 As shown, in DPPH solution, the hydrogel's color changed from purple to yellow due to DPPH reduction. Example 5 showed a free radical scavenging rate of 91.2%. APTS was added to the hydrogel. + In solution, APTS + The reduced color changes from green to colorless, and the free radical scavenging rate can reach 88.4%. The antioxidant properties of the hydrogel are mainly due to the free radical scavenging ability of the phenolic hydroxyl groups of tannic acid or polydopamine; the phenolic hydroxyl groups are strong free radical terminators.

[0106] (6) Antibacterial properties: To study the antibacterial properties of the hydrogel in Example 5, we used Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli) as model bacteria. Figure 8 As shown, after co-culturing the hydrogel and bacterial suspension, the bacterial suspension was diluted and spread. At the same dilution factor, the number of colonies in the blank group and the hydrogel group showed a significant order of magnitude difference. In Example 5, the hydrogel showed an inhibition rate of 92.4% against Staphylococcus aureus and 97.3% against Escherichia coli.

[0107] (7) Liver hemostasis: The hemostatic effect of the hydrogel in Example 5 was evaluated using a rat liver bloodletting model, such as... Figure 9As shown, the untreated group of rats exhibited significant hemorrhage (approximately 630 mg) with blood flowing freely from the liver. In contrast, the hemorrhage volume of the hydrogel in Example 5 was only six percent of that in the blank control group (approximately 40 mg), and the hemorrhage volume of the hydrogel in Example 2 was approximately 50 mg. There was a significant difference in hemorrhage volume between the blank control group and the hydrogel group (P < 0.01).

[0108] (8) Anti-inflammatory properties: The anti-inflammatory ability of the hydrogel in Example 5 on wounds was assessed by evaluating the expression level of the inflammatory cytokine IL-6. IL-6 is a multifunctional cytokine produced by fibroblasts, monocytes / macrophages, T lymphocytes, B lymphocytes, epithelial cells, keratinocytes, and various tumor cells. IL-6 plays an important role in regulating immune responses, acute phase responses, and the body's anti-infective immune response. IL-6 is generated first and its level rises rapidly after infection and inflammation, reaching a peak within 2 hours. We returned the liver to the rats after hemostasis, sutured it, and removed the damaged liver again after 24 hours for immunohistochemical staining. The blank group consisted of livers without hydrogel hemostasis. Figure 10 As shown, compared with the control group, the amount of IL-6 secreted from the wound after hemostasis with the hydrogel of Example 5 was much smaller than that in the blank group, indicating that the hydrogel of Example 5 can effectively reduce inflammation.

[0109] (9) Wound healing performance: The hydrogel in Example 5 demonstrated good wound healing properties. Figure 11 As shown, on the third day, the granulation tissue at the wound site was more abundant, and the healing rate was far superior to that of the control group. The combined treatment with the hydrogel and ES in Example 5 demonstrated even better repair effects. By the tenth day, the wound tissue in the combined treatment group of the hydrogel and ES in Example 5 had completely healed, while the wound healing rate in the control group was only 50%, and the wound healing rate in the hydrogel group of Example 5 was 72%. This indicates that the hydrogel in Example 5 can effectively promote wound repair, and the combined treatment with ES results in even faster wound repair.

[0110] (10) Adaptive Conductive Hydrogel Repair Mechanism: Adaptive performance, also known as the fluidity of the hydrogel, occurs at the critical point between fluid and gel. It can automatically adjust to the irregular shape of the external wound to adapt and fill the wound surface, satisfying the needs of irregular or deep wounds. For example... Figure 12 As shown. The hydrogel in Example 5 has a certain degree of viscosity, is not easy to fall off, and also has antibacterial, anti-inflammatory, and antioxidant effects, which can effectively stop bleeding. The hydrogel of Example 5 can promote wound healing by combining with externally applied electrical stimulation (ES). Its mechanism of action includes: downregulating inflammation, antibacterial activity, increasing tissue oxygenation, reducing wound blood flow, promoting angiogenesis, and promoting fibroblast proliferation.

[0111] Finally, it should be noted that although the embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments and application fields described above. The specific embodiments described above are merely illustrative and instructive, and not restrictive. Those skilled in the art can make many other forms based on the guidance of this specification and without departing from the scope of protection of the claims of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A hydrogel dressing, comprising, per 100 parts by weight: in, The weight ratio of borax to tannic acid is 1:3 or higher; The upper limit for the weight ratio of borax to tannic acid is 2:1; The lower limit of the weight ratio of borax to polyvinyl alcohol is 1:10; The upper limit for the weight ratio of borax to polyvinyl alcohol is 1:5; The preparation method of the hydrogel dressing includes the following steps: 1) Prepare a polyvinyl alcohol solution of a certain concentration; 2) Prepare a borax solution of a certain concentration; 3) Prepare a tannic acid solution of a certain concentration; 4) Prepare a Fan's recombinant collagen solution of a certain concentration; Mix the borax solution prepared in step 2) and the tannic acid solution prepared in step 3) thoroughly, then add the Fan's recombinant collagen solution prepared in step 4) to obtain solution A. Add an appropriate amount of solution A to the polyvinyl alcohol solution prepared in step 1), and add a certain amount of water as needed. Stir well and let it stand at room temperature for a certain period of time to swell, thus obtaining the hydrogel dressing; or Mix the borax solution prepared in step 2) with the recombinant collagen solution prepared in step 4) until homogeneous, then add the tannic acid solution prepared in step 3) to obtain solution B. Add an appropriate amount of solution B to the polyvinyl alcohol solution prepared in step 1), and add a certain amount of water as needed. Stir well and allow to stand at room temperature for a certain period of time to swell, thus obtaining the hydrogel dressing; or Mix the polyvinyl alcohol solution prepared in step 1) with the recombinant collagen solution prepared in step 4) to obtain solution C. Mix the borax solution prepared in step 2) with the tannic acid solution prepared in step 3) evenly to obtain solution D. Finally, mix solution C and solution D, and add a certain amount of water as needed. Stir well and let stand at room temperature for a certain period of time to swell, thus obtaining the hydrogel dressing.

2. The hydrogel dressing according to claim 1, wherein, The polyvinyl alcohol is 2 to 10 parts by weight.

3. The hydrogel dressing according to claim 1, wherein, The tannic acid is 0.5 to 5 parts by weight.

4. The hydrogel dressing according to claim 1, wherein, The amount of borax is 0.2 to 5 parts by weight.

5. The hydrogel dressing according to claim 1, wherein, The recombinant collagen from Fan's method is 0.5 to 5 parts by weight.

6. The hydrogel dressing according to claim 1, wherein, The polyvinyl alcohol has a weight-average molecular weight of 89,000-98,000 Da and a degree of alcoholysis greater than 99%.

7. The hydrogel dressing according to claim 1, used to promote wound healing.

8. A method for preparing a hydrogel dressing, comprising the following steps: 1) Prepare a polyvinyl alcohol solution of a certain concentration; 2) Prepare a borax solution of a certain concentration; 3) Prepare a tannic acid solution of a certain concentration; 4) Prepare a Fan's recombinant collagen solution of a certain concentration; Mix the borax solution prepared in step 2) and the tannic acid solution prepared in step 3) thoroughly, then add the Fan's recombinant collagen solution prepared in step 4) to obtain solution A. Add an appropriate amount of solution A to the polyvinyl alcohol solution prepared in step 1), and add a certain amount of water as needed. Stir well and let it stand at room temperature for a certain period of time to swell, thus obtaining the hydrogel dressing; or Mix the borax solution prepared in step 2) with the recombinant collagen solution prepared in step 4) evenly, and then add the tannic acid solution prepared in step 3) to obtain solution B. Take an appropriate amount of solution B and add it to the polyvinyl alcohol solution prepared in step 1), and add a certain amount of water as needed. After stirring evenly, let it stand at room temperature for a certain period of time to swell, and then obtain the hydrogel dressing. or Mix the polyvinyl alcohol solution prepared in step 1) with the recombinant collagen solution prepared in step 4) to obtain solution C. Mix the borax solution prepared in step 2) with the tannic acid solution prepared in step 3) evenly to obtain solution D. Finally, mix solution C and solution D, and add a certain amount of water as needed. Stir well and let stand at room temperature for a certain period of time to swell, thus obtaining the hydrogel dressing.

9. The use of the hydrogel dressing according to claim 1 in the preparation of a hydrogel dressing that promotes wound healing.

10. The use according to claim 9, wherein, The hydrogel dressing that promotes wound healing is used in combination with electrostimulation therapy.

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