Isoimperatorin-loaded dual-network hydrogel wound dressing as well as preparation method and application thereof

Abstract

The invention discloses a dual-network hydrogel wound dressing loaded with isoimperatorin as well as a preparation method and application of the dual-network hydrogel wound dressing, and belongs to the field of biomedical materials. The method comprises the following steps: modifying the surface of TOCNF with TA to obtain TA-coated TOCNF; and then compounding the TA-coated TOCNF / PVA hydrogel with PVA, and adding an ethanol solution containing isoimperatorin to finally form the dual-network TA-coated TOCNF / PVA hydrogel. Tannic acid with a convergence effect is introduced into the design, so that the hydrogel has certain antibacterial and adhesive properties; meanwhile, isoimperatorin with wound repairing activity is loaded, so that the bacteriostatic action is further synergistically enhanced, and the hydrogel dressing with a good promoting effect on wound healing is obtained. The preparation process only relates to simple mixing and freeze-thawing processes, a complex preparation process is not needed, and the preparation cost is low; the obtained hydrogel has self-healing ability, can be attached to irregular wounds, has bacteriostatic and antioxidant functions, and is suitable for large-scale production and wound treatment application.

Description

Technical Field

[0001] This invention relates to a dual-network hydrogel wound dressing loaded with isoimperatorin, its preparation method and application, belonging to the field of biomedical materials technology. Background Technology

[0002] As a protective barrier, the skin plays a crucial role in resisting the invasion of external pathogens and maintaining homeostasis. Because the skin is easily damaged through direct contact with the external environment, traumatic wounds are a common clinical problem. These wounds often have irregular shapes, large amounts of exudate, significant amounts of necrotic tissue, and are prone to secondary infection, resulting in slow healing and significantly increasing the difficulty of treatment. Wound healing involves four stages: hemostasis, inflammation, proliferation, and remodeling. During the inflammatory stage of wound healing, pathogens may invade and infect the wound. Therefore, skin wound healing is a complex and dynamic process; if this process is hindered, traumatic wounds may fail to heal.

[0003] Currently, medical dressings are a widely used clinical method for treating wounds. Traditional dressings mainly consist of medical gauze, primarily used to prevent bleeding and exudate. However, a drawback is that they tend to adhere to the skin and wound tissue after drying, making subsequent dressing changes painful or causing secondary trauma. Furthermore, there is a lack of highly effective and safe medical dressings for wound treatment that combine healing promotion and infection control. While some drugs loaded with natural products have shown potential, their application specifically for wound repair is limited. Therefore, there is an urgent need to develop a green, environmentally friendly, and effective treatment strategy.

[0004] Hydrogels, due to their three-dimensional hydrophilic network structure, can absorb exudate and maintain wound moisture, similar to the natural extracellular matrix, which is beneficial for tissue repair. Cellulose, as the most abundant natural polymer on Earth, has outstanding advantages such as wide availability, low cost, good biocompatibility, and environmental friendliness. When used to prepare hydrogel wound dressings, cellulose's high hydrophilicity can effectively absorb and lock in wound exudate, maintaining a suitable moist healing environment, thereby promoting tissue repair and regeneration. However, cellulose hydrogels have drawbacks such as poor mechanical properties, easy degradation, and lack of antibacterial properties, which limit their further development. Summary of the Invention

[0005] The purpose of this invention is to provide a dual-network hydrogel wound dressing loaded with isoimperatorin, its preparation method, and its application. The method involves only a simple mixing and freeze-thaw process, without the need for a complex preparation process. The prepared hydrogel wound dressing has excellent mechanical properties, antibacterial properties, antioxidant properties, and adhesive properties. The good astringency, antibacterial properties, and antioxidant activity of this dressing can effectively promote the healing of wounds.

[0006] To achieve the above-mentioned objective, this invention provides a method for preparing a dual-network hydrogel wound dressing loaded with isoimperatorin, comprising the following steps: (1) Add TA to the TOCNF solution, mix well, adjust the pH of the system to 8.0, and stir at room temperature in the dark for 12-16 hours to obtain TA@TOCNF; (2) Add PVA solution to the product obtained in step (1), vortex mix to form a uniform gel precursor solution; (3) Add isoimperatorin solution to the precursor solution obtained in step (2), vortex mix, pour into a mold, place in a -20°C refrigerator, freeze-thaw to obtain a double network hydrogel wound dressing loaded with isoimperatorin.

[0007] In a preferred embodiment, in step (1), the mass ratio between TA and TOCNF is (1-4):1, and the stirring time is 12-16 hours.

[0008] In a preferred embodiment, in step (1), the concentration of the TOCNF solution is 1-1.25 wt%, and the dispersion medium is water.

[0009] In a preferred embodiment, in step (1), the pH is adjusted using a Tris-HCl buffer solution with a pH of 8.0.

[0010] In a preferred embodiment, in step (2), the mass ratio between PVA and TOCNF is (5-12):1; the concentration of the PVA solution is 5-15wt%; and the dispersion medium is water.

[0011] In a preferred embodiment, in step (2), the mass ratio between isoimperatorin and TOCNF is 1:(2.67-10), the concentration of the isoimperatorin solution is 10-35 mg / mL, and the dispersion medium is ethanol.

[0012] In a preferred embodiment, in step (3), the freezing time is 18-24 h and the thawing time is 6-10 h; the freezing-thawing process is repeated 3 times.

[0013] To achieve the above-mentioned objectives, the present invention also provides a dual-network hydrogel wound dressing loaded with isoimperatorin prepared by the above-mentioned preparation method.

[0014] To achieve the above-mentioned objectives, the present invention also provides the application of the dual-network hydrogel wound dressing loaded with isoimperatorin in biomedical dressings.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: This invention modifies TOCNF with TA, which has adhesive and astringent effects on wounds, endowing the hydrogel with certain adhesive and antibacterial properties. PVA is introduced through physical blending. This dressing forms a first network based on the hydrogen bonding of TA, TOCNF, and PVA. A second network is formed based on the intermolecular interactions of polyvinyl alcohol under the influence of crystalline microregions after freeze-thaw cycles. The PVA network enhances mechanical properties. Finally, an isoimperatorin solution is added to achieve the preparation of a uniformly structured dual-network TA@TOCNF / PVA hydrogel and the loading of the active small molecule drug isoimperatorin. In this invention, isoimperatorin has a dual function: it can effectively inhibit common wound pathogens and accelerate wound healing by regulating cellular inflammation and antioxidant effects. The porous structure within the hydrogel also gives it a unique advantage in drug delivery. The preparation process of this invention involves only simple mixing and freeze-thaw processes, without the need for complex preparation techniques; and the preparation cost is low, which is conducive to large-scale production and practical application; the prepared hydrogel is easy to freeze-thaw and mold, has good biocompatibility, and also has certain adhesion, antioxidant and antibacterial properties, which can be adapted to complex wounds with a lot of exudate and easy infection; at the same time, the presence of TA and isoimperatorin also has a good promoting effect on the healing of skin wounds, and has potential application potential in the fields of medicine and health, flexible materials, etc. Attached Figure Description

[0016] Figure 1 The image shows the actual product of the TA@TOCNF / PVA dual-network hydrogel loaded with isoimperatorin obtained in Example 1. Figure 2 This is a photograph of the tensile properties of the TA@TOCNF / PVA dual-network hydrogel loaded with isoimperatorin obtained in Example 2. Figure 3 The adhesion of the TA@TOCNF / PVA dual-network hydrogel loaded with isoimperatorin obtained in Example 2 to nitrile rubber, aluminum, and copper is shown in the figure. Figure 4 The image shows the antibacterial activity of the TA@TOCNF / PVA dual-network hydrogel loaded with isoimperatorin obtained in Example 2 against Escherichia coli. Figure 5 The image shows the wound healing effect of the TA@TOCNF / PVA dual-network hydrogel loaded with isoimperatorin obtained in Example 2 as a wound dressing. Detailed Implementation

[0017] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explanation of the present invention and are not intended to limit the present invention.

[0018] In this invention, "TOCNF" stands for "2,2,6,6-tetramethylpiperidine-N-oxygen radical oxidized cellulose nanofibers", "2,2,6,6-tetramethylpiperidine-N-oxygen radical" is abbreviated as "TEMPO", and "cellulose nanofibers" is abbreviated as "CNF". Therefore, TOCNF is also called "TEMPO oxidized CNF".

[0019] In this invention, "TA" represents "tannic acid"; "Tris-HCl buffer" represents "tris(hydroxymethyl)aminomethane-hydrochloric acid buffer"; and "PVA" represents "polyvinyl alcohol".

[0020] Example 1 A method for preparing a dual-network hydrogel wound dressing loaded with isoimperatorin includes the following steps: (1) Add 0.2 g TA to 20.0 g of 1.00 wt% TOCNF aqueous solution, mix well and adjust the pH of the system to 8.0 with Tris-HCl buffer solution of pH=8. Stir at room temperature in the dark for 12 hours to obtain TA@TOCNF; (2) Add 20 g of 5 wt% PVA aqueous solution to the product obtained in step (1), vortex mix evenly to form a uniform gel precursor solution; (3) Add 2 mL of ethanol dispersion of isoimperatorin with a concentration of 10 mg / mL to the precursor solution obtained in step (2), vortex mix, pour into a mold, place in a -20°C refrigerator, freeze (18 h) and thaw (6 h), repeat the freezing-thawing process 3 times to obtain the double network hydrogel wound dressing loaded with isoimperatorin.

[0021] Example 2 Unlike Example 1, in step (1), TA was 0.5 g and stirred at room temperature in the dark for 16 hours; in step (2), the concentration of PVA aqueous solution was 10 wt%; in step (3), the concentration of isoimperatorin ethanol dispersion was 30 mg / mL, and other conditions and parameters were the same as in Example 1.

[0022] Example 3 Unlike Example 1, in step (1), TA was 0.6 g, the concentration of TOCNF aqueous solution was 1.25 wt%, and the mixture was stirred at room temperature in the dark for 14 hours; in step (2), the concentration of PVA aqueous solution was 15 wt%; in step (3), the concentration of isoimperatorin ethanol dispersion was 30 mg / mL, and the freezing and thawing times were 24 h and 10 h, respectively. Other conditions and parameters were the same as in Example 1.

[0023] Example 4 Unlike Example 1, in step (1), TA was 1.0 g and the concentration of TOCNF aqueous solution was 1.25 wt%; in step (2), the concentration of PVA aqueous solution was 15 wt%; in step (3), the concentration of isoimperatorin ethanol dispersion was 30 mg / mL, and the freezing and thawing times were 20 h and 6 h, respectively. Other conditions and parameters were the same as in Example 1.

[0024] Example 5 Unlike Example 1, in step (2), the concentration of the PVA aqueous solution is 10 wt%; in step (3), the concentration of the isoimperatorin ethanol dispersion is 35 mg / mL, and other conditions and parameters are the same as in Example 1.

[0025] Comparative Example 1 A method for preparing a hydrogel wound dressing includes the following steps: Take 20.0 g of 1.00 wt% TOCNF aqueous solution, then add 20 g of 10 wt% PVA aqueous solution, vortex mix evenly, then pour into a mold, place in a -20°C freezer, freeze (18 h) - thaw (6 h), repeat the freeze-thaw process 3 times to obtain hydrogel wound dressing.

[0026] Comparative Example 2 Unlike Example 1, step (3) of adding isoimperatorin ethanol dispersion to the precursor solution is omitted. The other steps and the conditions and parameters involved in the steps are the same as in Example 1.

[0027] As an example, Example 1 demonstrates the preparation of a TA@TOCNF / PVA hydrogel loaded with isoimperatorin. For example... Figure 1 As shown, after freeze-thaw, the TA@TOCNF / PVA hydrogel loaded with isoimperatorin changed from a flowable solution to a gel with a uniform color. The uniform color proves that isoimperatorin and the precursor solution of the gel were successfully cross-linked, and uniform loading of isoimperatorin was achieved.

[0028] The stretchability of the TA@TOCNF / PVA hydrogel loaded with isoimperatorin prepared in Example 2 is as follows: Figure 2 As shown in the figure, the prepared TA@TOCNF / PVA hydrogel loaded with isoimperatorin was stretched from 3 cm to 8 cm, which is 266.7% of the original hydrogel. The hydrogel still maintained its integrity without any breakage. This shows that the hydrogel prepared by the present invention has good mechanical strength and can effectively resist mechanical stretching within a certain range.

[0029] The adhesion of the TA@TOCNF / PVA hydrogel loaded with isoimperatorin prepared in Example 2 is as follows: Figure 3 As shown in the figure, the prepared hydrogel has good adhesion to skin, paper, and plastic.

[0030] The antibacterial properties of the TA@TOCNF / PVA hydrogel loaded with isoimperatorin prepared in Example 2 are as follows: Figure 4 As shown in the figure, after culturing the hydrogel loaded with isoimperatorin with Escherichia coli for 24 h, obvious inhibition zones were formed around it. The size of the inhibition zones is shown in Table 1. After co-culturing the hydrogels prepared in other examples and comparative examples with Escherichia coli for 24 h, obvious inhibition zones were formed around the hydrogels prepared in the examples, while no inhibition zone was formed around the hydrogel prepared in comparative example 1. An inhibition zone was formed around the hydrogel prepared in comparative example 2, but the size of the inhibition zone was smaller. The specific size of the inhibition zone is shown in Table 1. This proves that the TA@TOCNF / PVA hydrogel loaded with isoimperatorin has good antibacterial activity against Escherichia coli.

[0031] The self-healing TA@TOCNF / PVA hydrogel loaded with isoimperatorin prepared in Example 2, when used as a wound dressing, demonstrates its effectiveness in promoting wound healing. Figure 5 As shown in Table 1 and Figure 5 As can be seen, after applying the hydrogel to a wound approximately 1 cm in diameter, the wound size significantly decreased after 7 days, and it was essentially healed after 14 days, with a wound area of ​​only 0.042 cm². 2 The hydrogels prepared in other examples and comparative examples were used as wound dressings to promote wound healing. After applying the hydrogel prepared in the examples to a wound with a diameter of approximately 1 cm, the wound size significantly decreased after 3 days and was essentially healed after 14 days, with a wound area ranging from 0.029 to 0.047 cm². 2 After applying the hydrogels prepared in Comparative Example 1 and Comparative Example 2 to wounds approximately 1 cm in diameter, the wound areas were 0.106 cm² and 0.106 cm² respectively after 14 days. 2 0.057cm 2 This demonstrates that the TA@TOCNF / PVA hydrogel loaded with isoimperatorin has a significant effect on promoting wound healing.

[0032] Table 1. Size of the inhibition zone and wound area after 14 days. In summary, the hydrogels prepared in Examples 1-5 respectively exhibit good adhesion, antibacterial properties, and wound healing promotion performance. Adhesion is demonstrated by the fact that the TA@TOCNF / PVA hydrogel loaded with isoimperatorin can adhere to the surfaces of materials such as skin, cardboard, and plastics. As shown in Table 1, the antibacterial effect of Comparative Example 1 against Escherichia coli is 0, while the antibacterial effect of the hydrogel against Escherichia coli is significantly improved after the addition of TA. Further introduction of isoimperatorin further enhances the antibacterial effect of the hydrogel dressing against Escherichia coli. Compared to Comparative Example 1, this hydrogel adheres to the wound surface, resulting in a smaller wound area after 14 days, demonstrating a better healing effect.

[0033] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A method for preparing a dual-network hydrogel wound dressing loaded with isoimperatorin, characterized in that, Includes the following steps: (1) Add TA to the TOCNF solution, mix well, adjust the pH of the system to 8.0, and stir at room temperature in the dark for 12-16 hours to obtain TA@TOCNF; (2) Add PVA solution to the product obtained in step (1), vortex mix to form a uniform gel precursor solution; (3) Add isoimperatorin solution to the precursor solution obtained in step (2), vortex mix, pour into a mold, place in a -20°C refrigerator, freeze-thaw to obtain a double network hydrogel wound dressing loaded with isoimperatorin.

2. The method for preparing a dual-network hydrogel wound dressing loaded with isoimperatorin according to claim 1, characterized in that, In step (1), the mass ratio between TA and TOCNF is (1-4):1, and the stirring time is 12 h.

3. A method for preparing a dual-network hydrogel wound dressing loaded with isoimperatorin according to claim 1 or 2, characterized in that, In step (1), the concentration of the TOCNF solution is 1-1.25 wt%, and the dispersion medium is water.

4. A method for preparing a dual-network hydrogel wound dressing loaded with isoimperatorin according to claim 1 or 2, characterized in that, In step (1), the pH is adjusted using Tris-HCl buffer solution with a pH of 8.

0.

5. A method for preparing a dual-network hydrogel wound dressing loaded with isoimperatorin according to claim 1 or 2, characterized in that, In step (2), the mass ratio between PVA and TOCNF is (5-12):1, the concentration of the PVA solution is 5-15wt%, and the dispersion medium is water.

6. A method for preparing a dual-network hydrogel wound dressing loaded with isoimperatorin according to claim 1 or 2, characterized in that, In step (2), the mass ratio between isoimperatorin and TOCNF is 1:(2.67-10), the concentration of the isoimperatorin solution is 10-35 mg / mL, and the dispersion medium is ethanol.

7. A method for preparing a dual-network hydrogel wound dressing loaded with isoimperatorin according to claim 1 or 2, characterized in that, In step (3), the freezing time is 18-24 h and the thawing time is 6-10 h; the freezing-thawing process is repeated 3 times.

8. A dual-network hydrogel wound dressing loaded with isoimperatorin, characterized in that, It is prepared by the method described in any one of claims 1-7.

9. The application of the dual-network hydrogel wound dressing loaded with isoimperatorin as described in claim 8 in biomedical dressings.

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