Visual hydrogel based on multiple response mechanisms and preparation method and application thereof

Abstract

The invention relates to the technical field of biological medicine, and particularly provides visual hydrogel based on multiple response mechanisms as well as a preparation method and application of the visual hydrogel. The preparation method comprises the following steps: (1) preparing an inclusion compound from beta-cyclodextrin, hydroxypropyl-beta-cyclodextrin and anthocyanin; (2) respectively preparing a polyvinyl alcohol / rhein solution and a mixed solution of quaternary ammonium salt chitosan / hyaluronic acid / kappa-carrageenan; and (3) initiating dynamic crosslinking through phenylboronic acid, constructing a multi-network structure by cooperating with tannic acid, the clathrate compound and genipin, and performing gradient temperature control curing to form the hydrogel. The hydrogel has the pH / temperature / ROS response characteristic, the wound surface microenvironment state can be fed back in real time by means of anthocyanin color change, meanwhile, hyaluronic acid / polyvinyl alcohol can construct a 3D microchannel structure, ordered arrangement of collagen is promoted, wound surface healing is accelerated, and the wound surface healing effect is improved. Therefore, the problems that direct loading of anthocyanin is unstable, and a single response mechanism is difficult to adapt to a complicated microenvironment of a diabetic wound surface are solved.

Description

Technical Field

[0001] The present invention relates to the field of biomedical technologies, and particularly to a visual hydrogel based on a multiple response mechanism, a preparation method thereof, and an application thereof. Background Art

[0002] The treatment of diabetic wounds faces multiple challenges, including susceptibility to bacterial infection, imbalance of the inflammatory microenvironment, excessive exudate, and difficulty in real-time monitoring of the healing process. Traditional hydrogel wound dressings have attracted much attention in the field of wound care due to their excellent moisture retention, breathability, and biocompatibility. However, existing products generally have the following limitations: (1) Most dressings have a single function, only providing a physical barrier and a moist environment, lacking the synergistic effects of antibacterial, anti-inflammatory, or promoting healing; (2) Drug release depends on simple diffusion and cannot respond to changes in the wound microenvironment to achieve on-demand release; (3) It is unable to intuitively reflect the wound state, requiring frequent replacement or relying on external detection means; (4) Some materials are prone to swelling and rupture or have poor adhesion, making it difficult to adapt to the treatment of complex wounds such as diabetic ulcers.

[0003] In recent years, the combination of intelligent responsive materials and visualization technologies has become a research hotspot. For example, pH-sensitive pigments can indicate the wound infection state through color changes, and natural polymers have been widely used to construct multifunctional hydrogel networks due to their antibacterial properties, responsiveness, and crosslinkable characteristics. Patent application 202411567623.7 discloses "a bilayer hydrogel for wound repair and infection monitoring, a preparation method thereof, and an application thereof". The bilayer hydrogel disclosed in this patent application utilizes the pH-responsive color change property of mulberry anthocyanin to achieve wound infection monitoring. The upper-layer hydrogel is based on a sodium alginate hydrogel network crosslinked by metal cations, and the lower-layer hydrogel is a dynamic hydrogel network based on Schiff base reaction containing quaternary ammonium salt groups. However, the visualization material used in this patent is prone to degradation, has poor direct loading stability, and cannot accurately indicate the change in the degree of wound infection. In addition, the single response mechanism adopted in this patent is difficult to meet the needs of complex wound management such as diabetes. Summary of the Invention

[0004] To solve the above problems, the present invention combines anthocyanin, β-cyclodextrin, and hydroxypropyl-β-cyclodextrin to form an inclusion complex, which improves the stability of anthocyanin and provides a visual basis for color change of the hydrogel. The hydrogel prepared by the present invention has triple response characteristics of pH / temperature / ROS, breaking through the defect that a single response mechanism is difficult to adapt to the complex microenvironment of diabetic wounds. At the same time, the synergistic antibacterial mechanism of quaternary ammonium salt chitosan, κ-carrageenan, and rhein effectively reduces the risk of wound infection. Meanwhile, hyaluronic acid / polyvinyl alcohol can construct a 3D microchannel structure to promote the orderly arrangement of collagen and accelerate the healing of diabetic wounds.

[0005] To this end, the present invention provides a method for preparing a visual hydrogel based on a multiple response mechanism, and the preparation method includes the following steps: S100. Dissolve β-cyclodextrin and hydroxypropyl-β-cyclodextrin in deionized water, add anthocyanin, and perform ultrasonic treatment, magnetic stirring treatment, filtration treatment, and freeze-drying treatment under light-shielded conditions to obtain an inclusion compound; S200. Add polyvinyl alcohol and rhein to deionized water to obtain a first solution; dissolve quaternary ammonium salt chitosan, hyaluronic acid, and κ-carrageenan in deionized water to obtain a second solution; S300. Add phenylboronic acid to the first solution, and then mix it with the second solution to obtain a first mixture; and sequentially add tannic acid, the inclusion compound, and genipin to the first mixture, and perform post-treatment to obtain a hydrogel.

[0006] In an example of the present invention, step S300 specifically includes: S310. Add phenylboronic acid to the first solution, mix well, and then slowly add it to the second solution to obtain a first mixture; S320. Add tannic acid and the inclusion compound to the first mixture, mix evenly, and add genipin, and react under light-shielded conditions at room temperature to obtain a second mixture; S330. Inject the second mixture into a mold, let it stand at room temperature, and then perform refrigeration curing to obtain a hydrogel.

[0007] In an example of the present invention, in step S100, the mass concentration of β-cyclodextrin is 2%, the mass concentration of hydroxypropyl-β-cyclodextrin is 2%, and the mass concentration of anthocyanin is 0.4 - 0.6%.

[0008] In an example of the present invention, in step S200, the mass concentration of polyvinyl alcohol is 5 - 10%, the mass concentration of rhein is 0.2 - 0.5%, the mass concentration of quaternary ammonium salt chitosan is 3 - 6%, the mass concentration of hyaluronic acid is 2 - 5%, and the mass concentration of κ-carrageenan is 2 - 4%.

[0009] In an example of the present invention, in step S300, the mass concentration of phenylboronic acid is 1 - 3%, the mass concentration of tannic acid is 1 - 3%, the mass concentration of the inclusion compound is 0.5%, and the mass concentration of genipin is 0.3 - 0.5%.

[0010] In an example of the present invention, in step S100, the ultrasonic treatment is carried out for 20 minutes, the power is 400W, the frequency is 30kHz, the temperature is 25°C, the time of magnetic stirring treatment is 4 - 6h, and the filtration treatment uses a 0.45μm filter membrane.

[0011] In an example of the present invention, in step S330, the temperature of refrigeration curing is 3 - 5°C, and the time is 5 - 7h.

[0012] In an example of the present invention, there is also provided a visual hydrogel based on a multiple response mechanism, and the hydrogel is obtained by using the preparation method of any one of the above.

[0013] In an example of the present invention, there is also provided an application of a visual hydrogel based on a multiple response mechanism, and the hydrogel is applied to the repair of diabetic wounds.

[0014] After adopting the technical solution of the present invention, the following technical effects can be achieved: (1) The co-modification of β-cyclodextrin and hydroxypropyl-β-cyclodextrin can form a double-layer inclusion structure. The cavity of β-cyclodextrin can accommodate anthocyanin molecules, and the outer modification of hydroxypropyl-β-cyclodextrin can further stabilize the inclusion complex and prevent the degradation and loss of anthocyanin in the external environment. β-cyclodextrin has a conical structure with hydrophobic interior and hydrophilic exterior, which can form an inclusion complex with anthocyanin molecules, thereby improving the water solubility and stability of anthocyanin. Hydroxypropyl-β-cyclodextrin is an etherified derivative of β-cyclodextrin, which has higher water solubility and lower toxicity, and can further enhance the stability and encapsulation efficiency of the inclusion complex. The cavitation effect of ultrasonic waves can provide mechanical energy to promote the formation of the inclusion complex. Through the oscillation and shearing action of ultrasonic waves, the inclusion complex particles can be broken into smaller particle sizes, which helps to form a stable dispersion system of the inclusion complex in the hydrogel. When the pH of the wound infection area increases, intramolecular charge transfer occurs in anthocyanin, and the color changes from purple to blue-green, which can reflect the pH change of the wound microenvironment in real time and avoid frequent dressing changes; (2) Based on the dual cross-linking network of phenylboronic acid-o-dihydroxy dynamic covalent bonds and κ-carrageenan thermosensitive phase change, combined with the characteristic that the solubility of rhein increases with the increase of pH, a triple environmental response of pH / reactive oxygen species / temperature is realized, which can accurately adapt to the complex pathological environment of diabetic wounds, such as high oxidative stress, higher temperature and pH waves caused by infection); (3) Rhein / tannic acid inhibits the NF-κB and MAPK inflammatory signaling pathways, reduces the expression of pro-inflammatory factors, and improves the anti-inflammatory ability of the hydrogel; (4) Quaternary ammonium chitosan and κ-carrageenan can form an electrostatic capture network, which can effectively capture and fix negatively charged bacteria, prevent the movement and reproduction of bacteria on the wound surface. Rhein can change the permeability of the bacterial cell membrane, destroy its integrity, cause the leakage of intracellular substances, and ultimately lead to the death of bacteria. The two work together to improve the antibacterial ability of the hydrogel and reduce the dependence on antibiotics; (5) Optimize the network topology structure through a step-by-step cross-linking strategy to improve the tensile strength; (6) Hyaluronic acid / PVA constructs a 3D microchannel structure to guide the directional migration of fibroblasts, activate the TGF-β signaling pathway at the same time, promote the orderly arrangement of collagen, and accelerate the healing of diabetic wounds. Description of the Drawings

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings to be used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings: Figure 1 Scanning electron microscope (SEM) image of the hydrogel prepared for Example 1; Figure 2 Color change of the hydrogel prepared for Example 1 under different pH conditions; Figure 3 Anti-tensile test results of the hydrogel prepared for Example 1; Figure 4 Cumulative release amount of rhein over time for the hydrogel prepared for Example 1 under different pH values and different H 2 O 2 concentration conditions, where A is the cumulative release amount of rhein over time under pH 7.2 conditions, and B is the cumulative release amount of rhein over time under pH 8.2 conditions; Figure 5 Cell compatibility test results of the hydrogel prepared for Example 1; Figure 6 Wound changes in diabetic mice in different treatment groups; Figure 7 Masson staining results of the infected wound experiment in diabetic mice. Detailed implementation manners

[0016] In order to more clearly understand the above objects, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

[0017] Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0018] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following combines Figures 1 to 7 to make a detailed description of the specific embodiments of the present invention.

[0019] The hydrogel prepared by the present invention has multiple response mechanisms and can respond to external stimuli such as pH, temperature, and ROS. In the microenvironment of diabetic wounds, the pH value usually changes. The hydrogel can adjust its own properties according to the change of wound pH to better adapt to the dynamic changes of the wound and improve the treatment effect. At the same time, the responsiveness to temperature and ROS also enables it to more flexibly respond to the complex microenvironment of diabetic wounds and achieve precise treatment and repair.

[0020] Furthermore, by adding β-CD / HP-β-CD / anthocyanin inclusion complex, the hydrogel has visualization characteristics. Anthocyanin can change color according to the change of environmental pH. Through the inclusion effect of β-CD / HP-β-CD, the stability and solubility of anthocyanin are improved, enabling it to play a more effective role in visual monitoring in the hydrogel.

[0021] Preferably, by reasonably proportioning and combining materials with different functions, such as PVA providing good gel-forming properties and mechanical properties, rhein having pharmacological effects such as anti-inflammatory, quaternary ammonium salt chitosan enhancing antibacterial properties, hyaluronic acid promoting cell proliferation and tissue repair, κ-carrageenan participating in the construction of the network structure, phenylboronic acid participating in the cross-linking reaction, tannic acid providing antioxidant properties, and β-CD / HP-β-CD / anthocyanin inclusion complex realizing the visualization function, etc., the synergistic effect of multiple functions is achieved, enabling the hydrogel to play a role from multiple perspectives during the wound repair process and promoting the rapid healing of the wound and tissue regeneration.

[0022] For example, the mass concentrations of each material are precisely controlled and optimized, such as PVA 5 - 10%, rhein 0.2 - 0.5%, QC 3 - 6%, HA 2 - 5%, κ-carrageenan 2 - 4%, etc., ensuring that the hydrogel has appropriate physical properties and chemical stability, enabling it to maintain a good shape and performance in practical applications, effectively fitting the wound and providing a lasting repair effect.

[0023] Preferably, the hydrogel of this embodiment is specifically designed for the repair of diabetic wounds, fully considering the special pathophysiological characteristics of diabetic wounds, such as hyperglycemia, microcirculation disorders, and relatively severe inflammatory reactions. Through the synergistic effect of multiple components, it can effectively improve the microenvironment of the wound, promote angiogenesis and tissue repair, improve the healing speed and quality of diabetic wounds, provide an effective means for treating wounds for diabetic patients, and reduce the pain of patients and the social medical burden.

[0024] Furthermore, in clinical applications, this hydrogel can be used as a new type of dressing or drug carrier for treating various types of diabetic wounds, such as diabetic foot ulcers, pressure sores, etc. Its good biocompatibility, multiple response mechanisms, and visualization function make it safer, more effective, and easier to monitor during use, and it is expected to become an ideal product in the field of diabetic wound repair, with high clinical application value and market promotion potential.

[0025] Preferably, the selected materials such as polyvinyl alcohol (PVA), chitosan, etc. all have good biocompatibility, so that the prepared hydrogel will not cause obvious immune reactions or toxic reactions when applied in vivo, ensuring the safety and reliability of use, and is particularly suitable for biomedical fields such as diabetic wound repair.

[0026] Optimally, the reaction conditions adopted during the preparation process are relatively mild, avoiding the destruction of materials and active ingredients under extreme conditions such as high temperature and high pressure, which is beneficial to maintaining the biological activity and stability of each component, and is also beneficial to energy conservation and reducing production costs. By precisely controlling parameters such as the reaction time, temperature, and stirring speed of each step, as well as strictly controlling the mass concentration of each material, the preparation process has good repeatability and can stably produce hydrogel products with consistent quality and stable performance, meeting the strict requirements of clinical applications and industrial production for product quality stability.

[0027]

Example 1

[0028]

Example 2

[0029] (2) Add 50 mg of PVA powder and 4 mg of rhein to 1 mL of deionized water, heat and stir until completely dissolved, and cool to room temperature to obtain the PVA / rhein solution; add 30 mg of QC, 20 mg of HA, and 20 mg of κ-carrageenan to 1 mL of deionized water, heat and fully dissolve to obtain the QC / HA / carrageenan solution.

[0030] (3) Add 10 mg of phenylboronic acid to the PVA / rhein solution, mix well, then slowly add the QC / HA / carrageenan solution to obtain mixture A; add 10 mg of tannic acid and 5 mg of the β-CD / HP-β-CD / anthocyanin inclusion complex to mixture A, stir and mix well, then add 3 mg of genipin, mix well, react at 37 °C under light-shielded conditions for 24 hours, inject the mixture into a mold, let it stand at room temperature for 1 hour, and then refrigerate and solidify at 4 °C for 6 hours to form a hydrogel.

[0031]

Example 3

[0032] (2) Add 80 mg of PVA powder and 3 mg of rhein to 1 mL of deionized water, heat and stir until completely dissolved, and cool to room temperature to obtain the PVA / rhein solution; add 60 mg of QC, 50 mg of HA, and 40 mg of κ-carrageenan to 1 mL of deionized water, heat and fully dissolve to obtain the QC / HA / carrageenan solution.

[0033] (3) Add 30 mg of phenylboronic acid to the PVA / rhein solution, mix well, then slowly add the QC / HA / carrageenan solution to obtain mixture A; add 30 mg of tannic acid and 5 mg of the β-CD / HP-β-CD / anthocyanin inclusion complex to mixture A, stir and mix well, then add 5 mg of genipin, mix well, react at 37 °C under light-shielded conditions for 24 hours, inject the mixture into a mold, let it stand at room temperature for 1 hour, and then refrigerate and solidify at 4 °C for 6 hours to form a hydrogel.

[0034]

Example 4

[0035] (2)Add 80 mg of PVA powder and 2 mg of rhein to 1 mL of deionized water, heat and stir until completely dissolved, and cool to room temperature to obtain the PVA / rhein solution; add 50 mg of QC, 50 mg of HA, and 40 mg of κ-carrageenan to 1 mL of deionized water, heat and dissolve thoroughly to obtain the QC / HA / carrageenan solution.

[0036] (3)Add 30 mg of phenylboronic acid to the PVA / rhein solution, mix well, then slowly add the QC / HA / carrageenan solution to obtain mixture A; add 30 mg of tannic acid and 5 mg of the β-CD / HP-β-CD / anthocyanin inclusion complex to mixture A, stir and mix well, then add 5 mg of genipin, mix well, react at 37 °C under dark conditions for 24 hours, inject the mixture into a mold, let it stand at room temperature for 1 hour, and then refrigerate and solidify at 4 °C for 6 hours to form a hydrogel.

[0037]

Example 5

[0038] (2)Add 80 mg of PVA powder and 2 mg of rhein to 1 mL of deionized water, heat and stir until completely dissolved, and cool to room temperature to obtain the PVA / rhein solution; add 40 mg of QC, 50 mg of HA, and 30 mg of κ-carrageenan to 1 mL of deionized water, heat and dissolve thoroughly to obtain the QC / HA / carrageenan solution.

[0039] (3)Add 30 mg of phenylboronic acid to the PVA / rhein solution, mix well, then slowly add the QC / HA / carrageenan solution to obtain mixture A; add 30 mg of tannic acid and 5 mg of the β-CD / HP-β-CD / anthocyanin inclusion complex to mixture A, stir and mix well, then add 5 mg of genipin, mix well, react at 37 °C under dark conditions for 24 hours, inject the mixture into a mold, let it stand at room temperature for 1 hour, and then refrigerate and solidify at 4 °C for 6 hours to form a hydrogel.

[0040]

Comparative Example 1

[0041] Performance Characterization (1)The hydrogel sample prepared in Example 1 was freeze-dried and then sputter-coated with gold, and its microscopic morphology was observed by scanning electron microscopy. The SEM image is as shown in Figure 1 . The results showed that the hydrogel had a three-dimensional porous structure, and the pore size was distributed in the range of 100-200 μm. This structure was beneficial to the absorption of exudate and gas exchange.

[0042] (2)The hydrogel samples prepared in Example 1 were immersed in buffer solutions with pH values of 5.0, 6.0, 7.0, and 8.0 respectively, and the color changes were recorded, as shown in Figure 2 . The hydrogel sample was purple at pH 5.0 (normal skin), blue-violet and blue at pH 6.0 and 7.0 respectively, and turned blue-green at pH 8.0 (infected environment), indicating that the hydrogel could reflect the pH change of the wound microenvironment in real time.

[0043] (3)The hydrogel sample in Example 1 was processed into strips (5 cm in length × 1 cm in width × 0.4 cm in thickness). At 25 °C, a universal testing machine was used to conduct a stress-strain test at a loading rate of 10 mm / min to investigate the tensile properties of the hydrogel.

[0044] The results are shown in Figure 3 . The maximum tensile strain of the hydrogel could reach 186.39%, and the stress could reach 67.6 kPa at this time, indicating that it had good tensile strength.

[0045] (4)The hydrogel samples prepared in Example 1 were placed under different pH buffer solutions (pH 7.2 and 8.2) and different H 2 O 2 concentrations (0.1 mM, 1 mM, 10 mM), and the cumulative release amount of rhein was quantitatively detected by HPLC.

[0046] The results are shown in Figure 4 . It can be seen that the cumulative release amount of rhein was affected by the pH value and H 2 O 2 concentration. When the pH value increased and (or) the H 2 O 2 concentration increased, the cumulative release amount of rhein increased, suggesting that this pH / ROS dual-responsive effect could enable the precise release of rhein in the specific environment of the inflammatory infection site.

[0047] (5) Using Escherichia coli and Staphylococcus aureus as the test strains, the antibacterial activity of the hydrogel samples in Example 1 and the comparative examples was determined by the plate colony counting method. Take 0.5 g of the hydrogel and mix it with 20 mL of the bacterial suspension (bacterial density 1×10 7 CFU / mL), then place it on a constant temperature shaking incubator and incubate at 37 °C for 30 minutes. After gradient diluting the bacterial suspension, spread it on a solid LB medium and incubate in an electrothermal constant temperature incubator at 37 °C for 12 hours. Calculate the inhibition rate according to the number of colonies on the plate. Inhibition rate = (number of colonies in the blank control group - number of colonies in the experimental group) / number of colonies in the blank control group * 100%.

[0048] The results are shown in Table 1. It can be seen that the hydrogel samples in the examples and the comparative examples all have good antibacterial effects, and the inhibition rates of the hydrogel samples in the three examples against Escherichia coli and Staphylococcus aureus are significantly higher than those of the comparative example samples.

[0049] Table 1 In vitro inhibition rate of hydrogels Inhibitory rate of Escherichia coli (%) Inhibitory rate of Staphylococcus aureus (%) Comparative Example 1 78.2 72.9 Example 1 99.4 97.9 Example 2 94.8 92.6 Example 3 90.3 83.5 Example 4 83.6 79.4 Example 5 80.9 76.2 (6) The cell compatibility of the hydrogel prepared in Example 1 was evaluated using L929 mouse fibroblasts. Add 1×10 5 cells per well to a 96-well plate and incubate for 24 h. In the control group, add 100 μL of complete medium to replace the original medium, and in the experimental group, add 100 μL of the hydrogel extract to replace the original medium. Incubate in an incubator at 37 °C and 5% CO 2 for 24 h, 48 h, and 72 h. When detecting at each time point, aspirate the medium in the wells, add 10 μL of MTT solution (final concentration 0.5 mg / mL) to each well, and continue to incubate for 4 hours. After the incubation is completed, carefully aspirate and discard the culture supernatant in the wells, add 100 μL of DMSO to each well, and gently shake for 10 minutes to fully dissolve the formazan crystals. Detect the absorbance OD 570 . Calculate the cell viability according to the following formula: Cell survival rate = (OD 570 experimental group / OD 570 control group) * 100%.

[0050] The results are as Figure 5 shown. After co-incubating the hydrogel with L929 mouse fibroblasts, the cell survival rate remained above 90%, indicating that it has no obvious toxic side effects.

[0051] (7) Investigate the effect of the hydrogel prepared in Example 1 on the infected wounds of diabetic mice. Eight male KM mice were randomly divided into two groups (control group, hydrogel group). Streptozotocin (STZ) was intraperitoneally injected (usually at a dose of 50 mg / kg / day for 5 consecutive days) to induce type 1 diabetes. Fasting blood glucose was monitored 72 hours after injection and throughout the experiment to confirm the successful establishment of the diabetic model (blood glucose ≥ 11.1 mmol / L). The mice were anesthetized with isoflurane, the back hair was shaved, and the skin was disinfected. Two circular full-thickness skin wounds were created at symmetric positions on the back using a sterile biopsy punch (6 mm in diameter). The control group was covered with PBS, and the hydrogel group was covered with the hydrogel. The wounds were cleaned daily and the treatment was reapplied. After the wounds had completely healed, Masson staining was performed on the healed tissues of the rats.

[0052] Figure 6 The figures show the wound surfaces of diabetic mice on the 0th, 3rd, 6th, and 12th days after hydrogel treatment. It can be seen that compared with the control group, the hydrogel group showed an effect of promoting wound healing. It could not only accelerate the healing rate but also had a positive effect on the repair of the surrounding tissues of the wound. The results of Masson staining are as Figure 7 shown. On the 12th day of the experiment, in the control group, the content of collagen fibers was relatively low, and the overall structure was relatively sparse, lacking a tight arrangement. In contrast, the generation of collagen fibers in the hydrogel group was significantly improved. Not only was the generated amount larger, but the arrangement was also more regular and orderly, showing a significant advantage of this group of treatments in promoting collagen fiber generation and tissue repair.

[0053] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing examples or perform equivalent replacements for some of the technical features. However, such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a visualized hydrogel based on a multiple response mechanism, characterized in that: The preparation method comprises the following steps: S100, dissolving β-cyclodextrin and hydroxypropyl-β-cyclodextrin in deionized water, adding anthocyanin, performing ultrasonic treatment, performing magnetic stirring treatment, filtering treatment, and freeze-drying treatment under light-proof conditions to obtain an inclusion compound; S200, adding polyvinyl alcohol and rhein into deionized water to obtain a first solution; dissolving quaternary ammonium salt chitosan, hyaluronic acid, and κ-carrageenan in deionized water to obtain a second solution; S300, adding phenylboric acid to the first solution, and mixing it with the second solution to obtain a first mixed solution; and sequentially adding tannic acid, the inclusion compound, and genipin to the first mixed solution, and performing post-treatment to obtain the hydrogel.

2. The preparation method according to claim 1, characterized in that: Step S300 specifically includes: S310, adding the phenylboric acid to the first solution, mixing thoroughly, and then slowly adding the phenylboric acid to the second solution to obtain the first mixed solution; S320, adding the tannic acid and the inclusion compound to the first mixed solution, mixing evenly, adding genipin, and reacting at room temperature in the dark to obtain a second mixed solution; S330, injecting the second mixed liquid into a mold, allowing it to stand at room temperature, and then refrigerating and curing it to obtain the hydrogel.

3. The preparation method according to claim 1, characterized in that: In step S100, the mass concentration of the β-cyclodextrin is 2%, the mass concentration of the hydroxypropyl-β-cyclodextrin is 2%, and the mass concentration of the anthocyanin is 0.4-0.6%.

4. The preparation method according to claim 1, characterized in that: In step S200, the mass concentration of the polyvinyl alcohol is 5-10%, the mass concentration of the rhein is 0.2-0.5%, the mass concentration of the quaternary ammonium salt chitosan is 3-6%, the mass concentration of the hyaluronic acid is 2-5%, and the mass concentration of the κ-carrageenan is 2-4%.

5. The preparation method according to claim 1, characterized in that: In step S300, the mass concentration of the phenylboric acid is 1-3%, the mass concentration of the tannic acid is 1-3%, the mass concentration of the inclusion complex is 0.5%, and the mass concentration of genipin is 0.3-0.5%.

6. The preparation method according to claim 1, characterized in that: In step S100, the ultrasonic treatment is performed for 20 minutes, with a power of 400 W, a frequency of 30 kHz, and a temperature of 25°C. The magnetic stirring treatment lasts for 4 to 6 hours. The filtration treatment uses a 0.45 μm filter membrane.

7. The preparation method according to claim 2, characterized in that: In step S330, the refrigerated curing temperature is 3-5°C and the time is 5-7 hours.

8. A visualized hydrogel based on a multiple response mechanism, characterized in that: The hydrogel is obtained by the preparation method according to any one of claims 1 to 7.

9. An application of a visualized hydrogel based on a multiple response mechanism, characterized in that: The hydrogel as claimed in claim 8 can be used for repairing diabetic wounds.

Images