A dressing with a repair function and its preparation method

Abstract

This application relates to the technical field of medical dressings, specifically to a preparation method of a dressing with a repair function, including: mixing citric acid-modified fucoidan and chitosan, adding water, heating and then performing ultrasonic oscillation, adding a crosslinking agent, heating while stirring to obtain a stock solution; mixing calendula extract, centella asiatica extract, dandelion extract, green tea extract, and honey, adding them to a high-speed disperser, adding water, after high-speed dispersion, adding them to the stock solution, continuing to stir, filtering, evaporating, standing to remove bubbles to obtain a precursor solution; soaking a porous scaffold in the precursor solution, allowing the precursor solution to penetrate into the pores of the porous scaffold through capillary action, and performing irradiation crosslinking and curing to obtain a dressing with a repair function. By selecting specific components for combination and using a specific preparation method, the prepared dressing with a repair function has good moisture retention, antibacterial properties, and mechanical strength while maintaining good wound repair function.

Description

Technical Field

[0001] The present application relates to the technical field of medical dressings, and particularly relates to a dressing with a repair function and a preparation method thereof. Background Art

[0002] Medical dressings are medical materials used to cover wounds, promote healing, and protect wounds from infection, and play a very important role in human health.

[0003] Traditional medical dressings are gauzes made of cotton or synthetic fibers, which have good air permeability but poor moisture retention and are prone to sticking to wounds. There are many types of modern dressings, including hydrogel dressings, hydrocolloid dressings, foam dressings, alginate dressings, silver ion dressings, and nanofiber dressings. Among them, hydrogel dressings and nanofiber dressings are relatively popular. Hydrogel dressings have good moisture retention, relieve pain, and are easy to use, but they are weak in strength and easy to tear; nanofiber dressings have natural antibacterial properties and high strength, but poor moisture retention and are relatively dependent on the liquid absorption capacity of the fibers.

[0004] Therefore, there is an urgent need to provide a more comprehensive medical dressing that is not only easy to use but also can meet various functions such as moisture retention, antibacterial property, and strength to cope with different types of traumas. Summary of the Invention

[0005] The present application aims to at least overcome one of the defects of the prior art, and provides a dressing with a repair function and a preparation method thereof. By selecting specific components for combination and adopting a specific preparation method, the prepared dressing with a repair function has the advantages of both hydrogel dressings and nanofiber dressings, and has good moisture retention, antibacterial property, and mechanical strength while maintaining good wound repair function.

[0006] In a first aspect, an embodiment of the present application provides a preparation method of a dressing with a repair function, which is realized through the following technical solutions:

[0007] A preparation method of a dressing with a repair function includes the following steps:

[0008] (1) Mix 20 - 40 parts of fucose polysaccharide modified by citric acid and 6 - 12 parts of chitosan by weight, add them to 60 - 120 parts of deionized water in an ultrasonic oscillator, heat up and then perform ultrasonic oscillation, and then add 2 - 3 parts of a crosslinking agent, and heat up while stirring to obtain a fucose polysaccharide hydrogel stock solution;

[0009] (2) Mix 1 - 2 parts of calendula extract, 1 - 2 parts of centella asiatica extract, 1 - 2 parts of dandelion extract, 2 - 3 parts of green tea extract, and 1 - 2 parts of honey, then add them to a high - speed disperser. Next, add 25 - 60 parts of deionized water. After high - speed dispersion, add the mixture to the fucoidan hydrogel stock solution described in step (1), continue to stir and mix, then filter, evaporate, and let it stand to remove bubbles to obtain a fucoidan hydrogel precursor solution;

[0010] (3) Immerse the nanofiber porous framework structure in the fucoidan hydrogel precursor solution described in step (2). Through capillary action, the fucoidan hydrogel precursor solution penetrates into the pores of the nanofiber porous framework structure, and through electron beam irradiation cross - linking and curing, a dressing with repair function is obtained.

[0011] A preparation method of a dressing with repair function according to an embodiment of the present application has at least the following beneficial effects:

[0012] In the preparation method of the present application, by filling the fucoidan hydrogel into the nanofiber porous framework structure, the nanofiber framework provides good mechanical strength and structural stability, making up for the lack of mechanical strength of the hydrogel. The composite dressing has both the flexibility of nanofibers and the elasticity of the hydrogel, adapting to the shape change of the wound; the high water content of the hydrogel can keep the wound moist, promote cell migration and proliferation, and accelerate wound healing. The lubricating effect of the hydrogel reduces the adhesion between the dressing and the wound, alleviating the pain during dressing change; the hydrogel can be used as a drug carrier to achieve slow and controlled release of drugs, and the nanofiber framework provides a drug release channel, which can load multiple drugs simultaneously to achieve multiple functions such as antibacterial, anti - inflammatory, and promoting healing; the high specific surface area of nanofibers is beneficial to cell attachment and growth, and the moist environment of the hydrogel promotes cell migration and proliferation. Both materials have good biocompatibility, reducing immune rejection reactions.

[0013] The fucoidan of the present application, as an excellent natural moisturizer, has good hygroscopicity and moisturizing properties. It can effectively lock in the moisture of the skin, prevent dryness, maintain a moist environment for the wound, promote cell regeneration and wound healing. At the same time, it has broad - spectrum antibacterial and antiviral effects, can stimulate cell regeneration, accelerate the repair speed of skin cells, and reduce scar formation. Fucoidan also has an immunomodulatory effect, can stimulate the body to produce specific immune responses, enhance immunity, and helps improve the local immune defense ability of the wound in the dressing, prevent the spread of infection, and further promote wound healing.

[0014] The fucoidan of the present application contains sulfate groups, which can complex with components such as calendula extract, centella asiatica extract, dandelion extract, and green tea extract to improve the loading capacity of the hydrogel and slow down the release of active ingredients.

[0015] The calendula extract of the present application is a natural ingredient, suitable for sensitive skin, capable of anti - inflammation, anti - bacteria, and promoting cell regeneration; the asiatic pennywort extract is a traditional herb with high safety, capable of promoting collagen synthesis, accelerating wound healing, and reducing scar formation; the dandelion extract can reduce inflammation and swelling, has anti - bacterial and anti - viral effects, promotes wound healing, and soothes the skin; the green tea extract is rich in polyphenolic compounds, with antioxidant, anti - inflammatory, and anti - bacterial effects, helping to reduce oxidative stress; honey is natural and easily obtainable, suitable for various types of wounds, with anti - bacterial, anti - inflammatory, and moisturizing effects, and can promote wound healing.

[0016] According to some embodiments of the present application, the preparation of the nanofiber porous framework structure in step (3) includes the following steps: Dissolve 5 - 10 parts by weight of polyvinyl alcohol in 100 - 120 parts by weight of absolute ethanol, mix evenly, add 20 - 60 parts by weight of hydrated aluminum silicate and 1 - 2 parts by weight of zinc chloride, mix evenly, add hydrochloric acid to adjust the pH value of the solution, and under the conditions of light - proof and protective gas atmosphere, while stirring, dropwise add 2 - 4 parts by weight of an ethanol solution of curcumin with a mass fraction of 50% to obtain a curcumin / hydrated aluminum silicate / polyvinyl alcohol solution; Use an electrospinning device to spin the curcumin / hydrated aluminum silicate / polyvinyl alcohol solution into curcumin / hydrated aluminum silicate / polyvinyl alcohol nanofibers under an electric field with a voltage of 10 - 30 kV, and collect the curcumin / hydrated aluminum silicate / polyvinyl alcohol nanofibers to form a nanofiber porous framework structure.

[0017] The hydrated aluminum silicate nanofibers of the present application have good biocompatibility, small size, high charge, strong hydrophilicity, can stably exist in an aqueous system, are easily well - dispersed in a solution. In addition, the hydrated aluminum silicate nanofibers have a unique cavity structure, have a strong adsorption capacity for various molecules, can load curcumin, and at the same time control the release rate of curcumin to achieve a sustained - release effect.

[0018] The polyvinyl alcohol of the present application has good hydrophilicity. The anti - bacterial, anti - inflammatory, and antioxidant properties of curcumin are combined with the hydrophilicity and water - retaining ability of polyvinyl alcohol, improving the hydrophilicity, high swelling property, and high drug absorbability of the dressing, and can promote the survival and proliferation of cells.

[0019] Zn of the present application 2+ Forms a complex with curcumin, which can enhance the structural strength of curcumin nanoparticles, enhance the stability of curcumin, improve the bioavailability of curcumin. Zinc ions also have anti - bacterial and anti - inflammatory effects, promote cell proliferation and collagen synthesis, and promote wound healing. When paired with curcumin, it can further enhance the anti - bacterial, anti - inflammatory, and wound - repair functions of the dressing.

[0020] Further, the pH value of the adjusting solution is 5 - 6.5. Adjusting the pH value of the solution to 5 - 6.5 can maintain the relative stability of the pH value of the reaction solution and inhibit the hydrolysis of Zn 2+ , which is beneficial to improving the stability of the curcumin-Zn 2+ complex, reducing the decomposition of curcumin, and promoting the progress of the reaction. If the pH value of the reaction system is too high, curcumin is easily decomposed, and Zn 2+ is prone to hydrolysis, affecting the formation of the complex.

[0021] Further, the parameters of the electrospinning device include: the receiving distance is 10 - 20 cm, and the liquid outlet speed is 5 - 20 μL / min.

[0022] According to some embodiments of the present application, the preparation method of the citric acid-modified fucoidan in step (1) includes the following steps:

[0023] Add fucoidan to the citric acid solution, add EDC, stir, react at a temperature of 70 - 90 °C for 2 h - 4 h, then cool the solution, adjust the pH to 6.5 - 7.5, dialyze with tap water for 40 h - 50 h, dialyze with distilled water for 20 h - 30 h, and then perform freeze-drying to obtain the citric acid-modified fucoidan.

[0024] Further, the dosage ratio of the fucoidan, the citric acid, and the EDC is (5 - 10) mg : (0.04 - 0.06) mmol : (0.05 - 0.1) mmol.

[0025] By using citric acid to modify fucoidan, the citric acid-modified fucoidan has good biocompatibility, will not cause obvious immune reactions or tissue damage, the solubility of the citric acid-modified fucoidan in water is improved, which is beneficial to its loading in the hydrogel. At the same time, the citric acid-modified fucoidan has better stability and biological activities, such as anti-inflammatory and antioxidant effects, improving the repair effect of the dressing.

[0026] According to some embodiments of the present application, the cross-linking agent in step (1) is at least one of N-hydroxymethylacrylamide, tetramethyl-1,2-ethylenediamine, hexamethylenetetramine, and aluminum glycolate.

[0027] According to some embodiments of the present application, the temperature of the ultrasonic oscillation in step (1) is 45 - 55 °C.

[0028] According to some embodiments of the present application, the frequency of the ultrasonic oscillation in step (1) is 25 - 30 kHz.

[0029] According to some embodiments of the present application, the ultrasonic intensity of the ultrasonic oscillation in step (1) is 2 - 3 W / cm2 。

[0030] According to some embodiments of the present application, the ultrasonic time of the ultrasonic oscillation in step (1) is 5 - 10 min.

[0031] According to some embodiments of the present application, the rotation speed of the stirring in step (1) is 300 - 400 r / min.

[0032] According to some embodiments of the present application, the stirring time in step (1) is 1 - 2 h.

[0033] According to some embodiments of the present application, the heating temperature in step (1) is 55 - 65 °C.

[0034] In a second aspect, the present application provides, in an embodiment, a dressing with a repair function prepared by the above - mentioned preparation method of a dressing with a repair function.

[0035] A dressing with a repair function according to an embodiment of the present application has at least the following beneficial effects:

[0036] The dressing with a repair function of the present application has good mechanical strength and structural stability, has both the flexibility of nanofibers and the elasticity of hydrogel, and can adapt to the shape change of the wound; it can keep the wound moist, promote cell migration and proliferation, and accelerate wound healing.

[0037] In a third aspect, the present application provides, in an embodiment, the application of the above - mentioned dressing with a repair function in repairing skin wounds. Using the dressing with a repair function of the present application to cover human skin wounds can accelerate the repair and healing of the wounds and reduce wound infection and inflammation. Specific Embodiments

[0038] To make the objectives, technical solutions, and advantages of the present application clearer, the following will further describe in detail with specific embodiments. The embodiments described herein are only a part of the embodiments of the present application and should not be construed as a limitation on the protection scope of the present application.

[0039] Example 1

[0040] Preparation of a dressing with a repair function:

[0041] (1) Preparation of nanofiber porous framework structure: Dissolve 8 parts by weight of polyvinyl alcohol in 110 parts of absolute ethanol, mix evenly, add 40 parts of hydrated aluminum silicate and 1.5 parts of zinc chloride, mix evenly, add hydrochloric acid to adjust the pH value of the solution to 6, and under the conditions of avoiding light and protective gas atmosphere, while stirring, dropwise add 3 parts of an ethanol solution of curcumin with a mass fraction of 50% to obtain a curcumin / hydrated aluminum silicate / polyvinyl alcohol solution; Use an electrospinning device with a receiving distance of 15 cm and a liquid outlet speed of 10 μL / min. Under an electric field of 20 kV voltage, spin the curcumin / hydrated aluminum silicate / polyvinyl alcohol solution into curcumin / hydrated aluminum silicate / polyvinyl alcohol nanofibers, and collect the curcumin / hydrated aluminum silicate / polyvinyl alcohol nanofibers to form a nanofiber porous framework structure;

[0042] (2) Preparation of citric acid-modified fucoidan: Add fucoidan to a citric acid solution, add EDC, stir, react at 80 °C for 3 h, then cool the solution and adjust the pH to 7, dialyze with running tap water for 45 h, dialyze with distilled water for 25 h, and then perform freeze-drying to obtain citric acid-modified fucoidan, where the dosage ratio of the fucoidan, the citric acid, and the EDC is 8 mg:0.05 mmol:0.07 mmol;

[0043] (3) Mix 30 parts by weight of citric acid-modified fucoidan and 9 parts of chitosan, add 90 parts of deionized water to an ultrasonic oscillator, heat up and perform ultrasonic oscillation for 8 min. The temperature of the ultrasonic oscillation is 50 °C, the frequency of the ultrasonic oscillation is 28 kHz, and the ultrasonic intensity of the ultrasonic oscillation is 2.5 W / cm 2 , then add 2.5 parts of N-hydroxymethylacrylamide, and while stirring at a speed of 350 r / min for 1.5 h, heat up to 60 °C to obtain a fucoidan hydrogel stock solution;

[0044] (4) Mix 1.5 parts of calendula extract, 1.5 parts of centella asiatica extract, 1.5 parts of dandelion extract, 2.5 parts of green tea extract, and 1.5 parts of honey, add them to a high-speed disperser, then add 40 parts of deionized water, after high-speed dispersion, add them to the fucoidan hydrogel stock solution, continue to stir and mix, then filter, evaporate, and stand to remove bubbles to obtain a fucoidan hydrogel precursor solution;

[0045] (5) Immerse the nanofiber porous framework structure in the fucoidan hydrogel precursor solution, and through capillary action, make the fucoidan hydrogel precursor solution penetrate into the pores of the nanofiber porous framework structure, and perform electron beam irradiation cross-linking and curing to obtain a dressing with a repair function.

[0046] Example 2

[0047] Preparation of a dressing with a repair function:

[0048] (1) Preparation of nanofiber porous framework structure: Dissolve 10 parts by weight of polyvinyl alcohol in 100 parts of absolute ethanol, mix evenly, add 60 parts of hydrated aluminum silicate and 1 part of zinc chloride, mix evenly, add hydrochloric acid to adjust the pH value of the solution to 6.5, and under the conditions of light avoidance and protective gas atmosphere, while stirring, dropwise add 2 parts of an ethanol solution of curcumin with a mass fraction of 50% to obtain a curcumin / hydrated aluminum silicate / polyvinyl alcohol solution; Use an electrospinning device with a receiving distance of 20 cm and a liquid outlet speed of 5 μL / min, and spin the curcumin / hydrated aluminum silicate / polyvinyl alcohol solution into curcumin / hydrated aluminum silicate / polyvinyl alcohol nanofibers under an electric field of 30 kV voltage, and collect the curcumin / hydrated aluminum silicate / polyvinyl alcohol nanofibers to form a nanofiber porous framework structure;

[0049] (2) Preparation of citric acid-modified fucoidan: Add fucoidan to a citric acid solution, add EDC, stir, react at 70 °C for 4 h, then cool the solution and adjust the pH to 6.5, dialyze with running tap water for 50 h and with distilled water for 20 h, and then perform freeze-drying to obtain citric acid-modified fucoidan, where the dosage ratio of the fucoidan, the citric acid, and the EDC is 10 mg:0.04 mmol:0.1 mmol;

[0050] (3) Mix 20 parts by weight of citric acid-modified fucoidan and 12 parts of chitosan, then add 60 parts of deionized water to an ultrasonic oscillator, heat up and perform ultrasonic oscillation for 10 min, the temperature of the ultrasonic oscillation is 45 °C, the frequency of the ultrasonic oscillation is 30 kHz, and the ultrasonic intensity of the ultrasonic oscillation is 2 W / cm 2 , then add 3 parts of tetramethylethylenediamine, and while stirring at a speed of 300 r / min for 2 h, heat up to 55 °C to obtain a fucoidan hydrogel stock solution;

[0051] (4) Mix 2 parts of calendula extract, 1 part of centella asiatica extract, 2 parts of dandelion extract, 2 parts of green tea extract, and 2 parts of honey, then add them to a high-speed disperser, and then add 25 parts of deionized water. After high-speed dispersion, add them to the fucoidan hydrogel stock solution, continue to stir and mix, then filter, evaporate, and let stand to remove bubbles to obtain a fucoidan hydrogel precursor solution;

[0052] (5) Immerse the nanofiber porous framework structure in the fucoidan hydrogel precursor solution, and make the fucoidan hydrogel precursor solution penetrate into the pores of the nanofiber porous framework structure through capillary action, and perform electron beam irradiation cross-linking and curing to obtain a dressing with a repair function.

[0053] Example 3

[0054] Preparation of a dressing with a repair function:

[0055] (1) Preparation of nanofiber porous framework structure: Dissolve 5 parts by weight of polyvinyl alcohol in 120 parts of absolute ethanol, mix evenly, add 20 parts of hydrated aluminosilicate and 2 parts of zinc chloride, mix evenly, add hydrochloric acid to adjust the pH value of the solution to 5, and under the conditions of light avoidance and protective gas atmosphere, while stirring, dropwise add 4 parts of an ethanol solution of curcumin with a mass fraction of 50% to obtain a curcumin / hydrated aluminosilicate / polyvinyl alcohol solution; Use an electrospinning device, with a receiving distance of 10 cm and a liquid outlet speed of 20 μL / min, and spin the curcumin / hydrated aluminosilicate / polyvinyl alcohol solution into curcumin / hydrated aluminosilicate / polyvinyl alcohol nanofibers under an electric field of 10 kV voltage, and collect the curcumin / hydrated aluminosilicate / polyvinyl alcohol nanofibers to form a nanofiber porous framework structure;

[0056] (2) Preparation of citric acid-modified fucoidan: Add fucoidan to a citric acid solution, add EDC, stir, react at 90 °C for 2 h, then cool the solution and adjust the pH to 7.5, dialyze with running tap water for 40 h and with distilled water for 30 h, and then perform freeze-drying to obtain citric acid-modified fucoidan, where the dosage ratio of the fucoidan, the citric acid, and the EDC is 5 mg:0.06 mmol:0.05 mmol;

[0057] (3) Mix 40 parts by weight of citric acid-modified fucoidan and 6 parts of chitosan, add 120 parts of deionized water to an ultrasonic oscillator, heat up and ultrasonically oscillate for 5 min, the temperature of the ultrasonic oscillation is 55 °C, the frequency of the ultrasonic oscillation is 25 kHz, and the ultrasonic intensity of the ultrasonic oscillation is 3 W / cm 2 , then add 2 parts of hexamethylenetetramine, and while stirring at a speed of 400 r / min for 1 h, heat up to 65 °C to obtain a fucoidan hydrogel stock solution;

[0058] (4) Mix 1 part of calendula extract, 2 parts of centella asiatica extract, 1 part of dandelion extract, 3 parts of green tea extract, and 1 part of honey, add them to a high-speed disperser, then add 60 parts of deionized water, after high-speed dispersion, add them to the fucoidan hydrogel stock solution, continue to stir and mix, then filter, evaporate, and let stand to remove bubbles to obtain a fucoidan hydrogel precursor solution;

[0059] (5) Immerse the nanofiber porous framework structure in the fucoidan hydrogel precursor solution, and make the fucoidan hydrogel precursor solution penetrate into the pores of the nanofiber porous framework structure through capillary action, and obtain a dressing with a repair function through electron beam irradiation crosslinking and curing.

[0060] Example 4

[0061] Preparation of a dressing with a repair function:

[0062] (1) Preparation of nanofiber porous framework structure: Dissolve 7 parts by weight of polyvinyl alcohol in 110 parts of absolute ethanol, mix evenly, add 50 parts of hydrated aluminum silicate and 2 parts of zinc chloride, mix evenly, add hydrochloric acid to adjust the pH value of the solution to 5.5, and under the conditions of light avoidance and protective gas atmosphere, while stirring, dropwise add 3 parts of an ethanol solution of curcumin with a mass fraction of 50% to obtain a curcumin / hydrated aluminum silicate / polyvinyl alcohol solution; Use an electrospinning device with a receiving distance of 15 cm and a liquid outlet speed of 15 μL / min. Under an electric field of 20 kV voltage, spin the curcumin / hydrated aluminum silicate / polyvinyl alcohol solution into curcumin / hydrated aluminum silicate / polyvinyl alcohol nanofibers, and collect the curcumin / hydrated aluminum silicate / polyvinyl alcohol nanofibers to form a nanofiber porous framework structure;

[0063] (2) Preparation of citric acid-modified fucoidan: Add fucoidan to a citric acid solution, add EDC, stir, react at 80 °C for 3 h, then cool the solution and adjust the pH to 6, dialyze with running tap water for 45 h, dialyze with distilled water for 25 h, and then perform freeze-drying to obtain citric acid-modified fucoidan, where the dosage ratio of the fucoidan, the citric acid, and the EDC is 6 mg: 0.05 mmol: 0.08 mmol;

[0064] (3) Mix 30 parts by weight of citric acid-modified fucoidan and 8 parts of chitosan, add 100 parts of deionized water to an ultrasonic oscillator, heat up and perform ultrasonic oscillation for 8 min. The temperature of the ultrasonic oscillation is 50 °C, the frequency of the ultrasonic oscillation is 28 kHz, and the ultrasonic intensity of the ultrasonic oscillation is 2.5 W / cm 2 , then add 2.5 parts of aluminum glycinate, and while stirring at a speed of 350 r / min for 1 h, heat up to 60 °C to obtain a fucoidan hydrogel stock solution;

[0065] (4) Mix 1.5 parts of calendula extract, 1 part of centella asiatica extract, 2 parts of dandelion extract, 2.5 parts of green tea extract, and 2 parts of honey, add them to a high-speed disperser, then add 35 parts of deionized water, after high-speed dispersion, add them to the fucoidan hydrogel stock solution, continue to stir and mix, then filter, evaporate, and let stand to remove bubbles to obtain a fucoidan hydrogel precursor solution;

[0066] (5) Immerse the nanofiber porous framework structure in the fucoidan hydrogel precursor solution, and through capillary action, enable the fucoidan hydrogel precursor solution to penetrate into the pores of the nanofiber porous framework structure, and perform electron beam irradiation crosslinking and curing to obtain a dressing with a repair function.

[0067] Comparative Example 1

[0068] Preparation of a dressing with a repair function:

[0069] (1) Preparation of nanofiber porous framework structure: Dissolve 8 parts by weight of polyvinyl alcohol in 110 parts of absolute ethanol, mix evenly, add 40 parts of hydrated aluminum silicate, mix evenly, add hydrochloric acid to adjust the pH value of the solution to 6, and under the conditions of avoiding light and protective gas atmosphere, while stirring, dropwise add 3 parts of an ethanol solution of curcumin with a mass fraction of 50% to obtain a curcumin / hydrated aluminum silicate / polyvinyl alcohol solution; Use an electrospinning device with a receiving distance of 15 cm and a liquid output speed of 10 μL / min. Under an electric field of 20 kV voltage, spin the curcumin / hydrated aluminum silicate / polyvinyl alcohol solution into curcumin / hydrated aluminum silicate / polyvinyl alcohol nanofibers, and collect the curcumin / hydrated aluminum silicate / polyvinyl alcohol nanofibers to form a nanofiber porous framework structure;

[0070] (2) Preparation of citric acid-modified fucoidan: Add fucoidan to a citric acid solution, add EDC, stir, react at 80 °C for 3 h, then cool the solution and adjust the pH to 7, dialyze with running tap water for 45 h and with distilled water for 25 h, and then through freeze-drying, obtain citric acid-modified fucoidan, where the dosage ratio of the fucoidan, the citric acid, and the EDC is 8 mg:0.05 mmol:0.07 mmol;

[0071] (3) Mix 30 parts by weight of citric acid-modified fucoidan and 9 parts of chitosan, then add 90 parts of deionized water to an ultrasonic oscillator, heat up and ultrasonically oscillate for 8 min at a temperature of 50 °C, an ultrasonic oscillation frequency of 28 kHz, and an ultrasonic intensity of 2.5 W / cm 2 , and then add 2.5 parts of N-hydroxymethylacrylamide, while stirring at a speed of 350 r / min for 1.5 h and heating up to 60 °C, to obtain a fucoidan hydrogel stock solution;

[0072] (4) Mix 1.5 parts of calendula extract, 1.5 parts of centella asiatica extract, 1.5 parts of dandelion extract, 2.5 parts of green tea extract, and 1.5 parts of honey, then add them to a high-speed disperser, and then add 40 parts of deionized water. After high-speed dispersion, add them to the fucoidan hydrogel stock solution, continue to stir and mix, then filter, evaporate, and let stand to remove bubbles to obtain a fucoidan hydrogel precursor solution;

[0073] (5) Immerse the nanofiber porous framework structure in the fucoidan hydrogel precursor solution, and through capillary action, make the fucoidan hydrogel precursor solution penetrate into the pores of the nanofiber porous framework structure, and through electron beam irradiation cross-linking and curing, obtain a dressing with a repair function.

[0074] Comparative Example 2

[0075] Preparation of a dressing with a repair function:

[0076] (1) Preparation of nanofiber porous framework structure: Dissolve 8 parts by weight of polyvinyl alcohol in 110 parts of absolute ethanol, mix evenly, add 40 parts of polylactic acid and 1.5 parts of zinc chloride, mix evenly, add hydrochloric acid to adjust the pH value of the solution to 6, and under the conditions of light avoidance and protective gas atmosphere, while stirring, dropwise add 3 parts of an ethanol solution of curcumin with a mass fraction of 50% to obtain a curcumin / polylactic acid / polyvinyl alcohol solution; Use an electrospinning device with a receiving distance of 15 cm and a liquid outlet speed of 10 μL / min, and spin the curcumin / polylactic acid / polyvinyl alcohol solution into curcumin / polylactic acid / polyvinyl alcohol nanofibers under an electric field of 20 kV voltage, and collect the curcumin / polylactic acid / polyvinyl alcohol nanofibers to form a nanofiber porous framework structure;

[0077] (2) Preparation of citric acid-modified fucoidan: Add fucoidan to a citric acid solution, add EDC, stir, react at 80 °C for 3 h, then cool the solution and adjust the pH to 7, dialyze with running tap water for 45 h and with distilled water for 25 h, and then perform freeze-drying to obtain citric acid-modified fucoidan, wherein the dosage ratio of the fucoidan, the citric acid and the EDC is 8 mg:0.05 mmol:0.07 mmol;

[0078] (3) Mix 30 parts by weight of citric acid-modified fucoidan and 9 parts of chitosan, add 90 parts of deionized water to an ultrasonic oscillator, heat up and perform ultrasonic oscillation for 8 min, the temperature of the ultrasonic oscillation is 50 °C, the frequency of the ultrasonic oscillation is 28 kHz, and the ultrasonic intensity of the ultrasonic oscillation is 2.5 W / cm 2 , then add 2.5 parts of N-hydroxymethylacrylamide, and while stirring at a speed of 350 r / min for 1.5 h, heat up to 60 °C to obtain a fucoidan hydrogel stock solution;

[0079] (4) Mix 1.5 parts of calendula extract, 1.5 parts of centella asiatica extract, 1.5 parts of dandelion extract, 2.5 parts of green tea extract, and 1.5 parts of honey, add them to a high-speed disperser, then add 40 parts of deionized water, after high-speed dispersion, add them to the fucoidan hydrogel stock solution, continue to stir and mix, then filter, evaporate, and stand to remove bubbles to obtain a fucoidan hydrogel precursor solution;

[0080] (5) Immerse the nanofiber porous framework structure in the fucoidan hydrogel precursor solution, and make the fucoidan hydrogel precursor solution penetrate into the pores of the nanofiber porous framework structure through capillary action, and perform electron beam irradiation crosslinking and curing to obtain a dressing with a repair function.

[0081] Comparative Example 3

[0082] Preparation of a dressing with a repair function:

[0083] (1) Preparation of nanofiber porous framework structure: Dissolve 8 parts by weight of polyvinyl alcohol in 110 parts of absolute ethanol, mix evenly, add 40 parts of hydrated aluminum silicate and 1.5 parts of zinc chloride, mix evenly, add hydrochloric acid to adjust the pH value of the solution to 6. Under the conditions of light avoidance and protective gas atmosphere, while stirring, dropwise add 3 parts of an ethanol solution of curcumin with a mass fraction of 50% to obtain a curcumin / hydrated aluminum silicate / polyvinyl alcohol solution; Use an electrospinning device with a receiving distance of 15 cm and a liquid output speed of 10 μL / min. Under an electric field of 20 kV voltage, spin the curcumin / hydrated aluminum silicate / polyvinyl alcohol solution into curcumin / hydrated aluminum silicate / polyvinyl alcohol nanofibers, and collect the curcumin / hydrated aluminum silicate / polyvinyl alcohol nanofibers to form a nanofiber porous framework structure;

[0084] (2) Mix 30 parts by weight of fucoidan and 9 parts of chitosan, then add 90 parts of deionized water to an ultrasonic oscillator, heat up and perform ultrasonic oscillation for 8 min. The temperature of ultrasonic oscillation is 50 °C, the frequency of ultrasonic oscillation is 28 kHz, and the ultrasonic intensity of ultrasonic oscillation is 2.5 W / cm 2 , then add 2.5 parts of N-hydroxymethylacrylamide, and while stirring at a speed of 350 r / min for 1.5 h, heat up to 60 °C to obtain a fucoidan hydrogel stock solution;

[0085] (3) Mix 1.5 parts of calendula extract, 1.5 parts of centella asiatica extract, 1.5 parts of dandelion extract, 2.5 parts of green tea extract, and 1.5 parts of honey, then add them to a high-speed disperser, and then add 40 parts of deionized water. After high-speed dispersion, add them to the fucoidan hydrogel stock solution, continue to stir and mix, then filter, evaporate, and let stand to remove bubbles to obtain a fucoidan hydrogel precursor solution;

[0086] (4) Immerse the nanofiber porous framework structure in the fucoidan hydrogel precursor solution, and through capillary action, make the fucoidan hydrogel precursor solution penetrate into the pores of the nanofiber porous framework structure, and perform electron beam irradiation cross-linking and curing to obtain a dressing with a repair function.

[0087] Experimental Example

[0088] Take the dressings with repair functions prepared in Examples 1-4 and Comparative Examples 1-3, and respectively test the tensile strength, compressive strength, flame retardancy and corrosion resistance. The test methods are as follows:

[0089] The breaking elongation rate is tested according to the standard of GB / T 2421803-2010.

[0090] The cytotoxicity is tested according to the standard of GB / T 14233.2-2005.

[0091] Test method for antibacterial property: The antibacterial activity of the skin wound repair film against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was tested by the agar diffusion method. The dressing with repair function was cut into discs with a diameter of 10 mm, sterilized under ultraviolet light for 30 min, and then placed on a solidified agar culture dish uniformly coated with 200 μL of bacterial culture solution (3×108 CFU / mL). After incubation at 37 °C for 24 h, the diameter of the inhibition zone around the dressing with repair function was recorded.

[0092] Test method for wound repair performance: The dressings with repair function prepared in Examples 1-4 and Comparative Examples 1-3 were used for the wounds of mice to repair the wounds, and the wound healing of the mice was observed. The test method was as follows: 70 mice (in good health, weighing 30-40 g) were taken and divided into 7 groups, with 10 mice in each group. The dressings with repair function of Examples 1-4 and Comparative Examples 1-3 were applied respectively. A 3 cm×3 cm hair-removed area was reserved on the back of the mice. After disinfection, a 1 cm×1 cm wound was made on the back with a scalpel. The above dressings were cut into 3 cm×3 cm in size and applied to the surface of the wound. The hemostasis of the wound was observed, and the dressing was changed once a day until the wound of the mice was completely healed. The healing time of the mouse wound was counted.

[0093] The test data are shown in Table 1 below:

[0094] Table 1

[0095]

[0096]

[0097] It can be seen from Table 1 that the dressings with repair function prepared in Examples 1-4 of the present application have good wound healing properties, no cytotoxicity, and at the same time have good tensile strength and antibacterial properties.

[0098] The preparation raw materials of the nanofiber porous framework structure in Comparative Example 1 do not contain zinc chloride, and the rest are the same as in Example 1. The antibacterial performance and wound healing performance of the dressing with repair function prepared in Comparative Example 1 are significantly worse, indicating that the Zn 2+ forming a complex with curcumin can enhance the structural strength of curcumin nanoparticles, enhance the stability of curcumin, improve the bioavailability of curcumin, and zinc ions also have antibacterial and anti-inflammatory effects, promote cell proliferation and the synthesis of collagen, and promote wound healing. Combining with curcumin can further enhance the antibacterial, anti-inflammatory and wound repair functions of the dressing.

[0099] In Comparative Example 2, the hydrated aluminum silicate in the raw materials for preparing the nanofiber porous framework structure was replaced with polylactic acid, and the rest was the same as in Example 1. The tensile strength, antibacterial property, and wound healing property of the dressing with a repair function prepared in Comparative Example 2 were significantly poorer. This shows that the hydrated aluminum silicate nanofibers of the present application have good biocompatibility, small size, high charge, strong hydrophilicity, can stably exist in an aqueous system, and are easily dispersed well in a solution. In addition, the hydrated aluminum silicate nanofibers have a unique cavity structure, strong adsorption ability for various molecules, can load curcumin, and at the same time control the release rate of curcumin to achieve a sustained release effect. Replacing hydrated aluminum silicate with polylactic acid will affect the comprehensive performance of the dressing.

[0100] In Comparative Example 3, the fucoidan in the raw materials was not modified with citric acid, and the rest was the same as in Example 1. The antibacterial property and wound healing property of the dressing with a repair function prepared in Comparative Example 3 were significantly poorer, and the tensile strength also decreased. This shows that by using citric acid to modify fucoidan, the citric acid-modified fucoidan has good biocompatibility and will not cause obvious immune reactions or tissue damage. The solubility of the citric acid-modified fucoidan in water is improved, which is beneficial to its loading in the hydrogel. At the same time, the citric acid-modified fucoidan has better stability and biological activity, such as anti-inflammatory and antioxidant effects, improving the repair effect of the dressing.

[0101] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, or variations can be made to these embodiments without departing from the principles and purposes of the present application, and the technical solutions after these changes, modifications, substitutions, or variations will fall within the protection scope of the present application.

Claims

1. A preparation method of a dressing with a repair function, characterized in that, It includes the following steps: (1) Mix 20 - 40 parts by weight of citric acid - modified fucoidan and 6 - 12 parts of chitosan, add them to 60 - 120 parts of deionized water in an ultrasonic oscillator, heat up and then perform ultrasonic oscillation. Then add 2 - 3 parts of a cross - linker, heat up while stirring to obtain a fucoidan hydrogel stock solution; (2) Mix 1 - 2 parts of calendula extract, 1 - 2 parts of centella asiatica extract, 1 - 2 parts of dandelion extract, 2 - 3 parts of green tea extract, and 1 - 2 parts of honey, add them to a high - speed disperser, then add 25 - 60 parts of deionized water. After high - speed dispersion, add them to the fucoidan hydrogel stock solution described in step (1), continue to stir and mix, then filter, evaporate, and stand still to remove bubbles to obtain a fucoidan hydrogel precursor solution; (3) Immerse the nanofiber porous framework structure in the fucoidan hydrogel precursor solution described in step (2), and make the fucoidan hydrogel precursor solution penetrate into the pores of the nanofiber porous framework structure through capillary action. Cross - link and cure it by electron beam irradiation to obtain a dressing with a repair function; The preparation of the nanofiber porous framework structure described in step (3) includes the following steps: Dissolve 5 - 10 parts by weight of polyvinyl alcohol in 100 - 120 parts of absolute ethanol, mix evenly, add 20 - 60 parts of hydrated aluminum silicate and 1 - 2 parts of zinc chloride, mix evenly, add hydrochloric acid to adjust the pH value of the solution. Under the conditions of avoiding light and in an inert gas atmosphere, dropwise add 2 - 4 parts of an ethanol solution of curcumin with a mass fraction of 50% while stirring to obtain a curcumin / hydrated aluminum silicate / polyvinyl alcohol solution; Use an electrospinning device to electrospin the curcumin / hydrated aluminum silicate / polyvinyl alcohol solution into curcumin / hydrated aluminum silicate / polyvinyl alcohol nanofibers under an electric field with a voltage of 10 - 30 kV, and collect the curcumin / hydrated aluminum silicate / polyvinyl alcohol nanofibers to form a nanofiber porous framework structure.

2. The preparation method of a dressing with a repair function according to claim 1, characterized in that, The pH value of the adjusted solution is 5 - 6.

5.

3. The preparation method of a dressing with a repair function according to claim 1, characterized in that, The parameters of the electrospinning device include: the receiving distance is 10 - 20 cm, and the liquid output speed is 5 - 20 μL / min.

4. The preparation method of a dressing with a repair function according to claim 1, characterized in that, The preparation method of the citric acid - modified fucoidan described in step (1) includes the following steps: Add fucoidan to a citric acid solution, add EDC, stir, react at a temperature of 70 - 90 °C for 2 - 4 h, then cool the solution, adjust the pH to 6.5 - 7.5, dialyze with running tap water for 40 - 50 h, dialyze with distilled water for 20 - 30 h, and then perform freeze - drying to obtain citric acid - modified fucoidan.

5. The preparation method of a dressing with a repair function according to claim 4, characterized in that, The dosage ratio of the fucoidan, the citric acid, and the EDC is (5 - 10) mg:(0.04 - 0.06) mmol:(0.05 - 0.1) mmol.

6. The preparation method of a dressing with a repair function according to claim 1, characterized in that, The cross - linker described in step (1) is at least one of N - hydroxymethylacrylamide, tetramethyl - 1,2 - ethylenediamine, hexamethylenetetramine, and aluminum glycinate.

7. The preparation method of a dressing with a repair function according to claim 1, characterized in that, The temperature of the ultrasonic oscillation in step (1) is 45 - 55 °C. A dressing with a repair function prepared by the preparation method of a dressing with a repair function according to any one of claims 1 to 7.

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