Hydrogel dressing based on traditional Chinese medicine polysaccharide and preparation method thereof

Abstract

The invention belongs to the technical field of biomedical materials, and particularly relates to a hydrogel dressing based on traditional Chinese medicine polysaccharide and a preparation method of the hydrogel dressing. The hydrogel dressing based on the traditional Chinese medicine polysaccharide is prepared from the following raw materials in parts by weight: 10 to 15 parts of gastrodia elata polysaccharide, 8 to 12 parts of rhizoma bletillae polysaccharide, 5 to 8 parts of astragalus polysaccharide, 1 to 3 parts of a nano-silver-baicalin compound, 2 to 3 parts of methacrylic anhydride, 0.02 to 0.05 part of VEGF, 0.4 to 1 part of PLGA, 0.1 to 0.3 part of Irgacure 2959, 20 to 30 parts of a 5% calcium chloride solution, 0.1 part of polyvinyl alcohol and 100 to 170 parts of PBS. A triple gel network structure is constructed through photocuring, ionic crosslinking and an emulsification-solvent evaporation method, so that the function integration of controlled release, antibiosis and vascular regeneration promotion is realized, and the clinical treatment requirements of complex wounds are effectively met.

Description

Technical Field

[0001] The invention belongs to the technical field of biomedical materials, and particularly relates to a hydrogel dressing based on traditional Chinese medicine polysaccharides and a preparation method thereof. Background Art

[0002] Hydrogel dressings are widely used in wound repair due to their high water content, good biocompatibility and breathability. Traditional hydrogel dressings are mainly based on synthetic polymer materials or natural polymer materials. Although they have functions such as moisturizing and promoting wound healing, they still have significant defects and are difficult to meet the clinical needs of complex wound treatment. Traditional dressings mostly focus on single functions such as antibacterial or moisturizing, while in actual clinical practice, complex wounds such as burns and infected wounds need to deal with multi-stage problems such as inflammatory response, bacterial infection, and angiogenesis at the same time. Although the natural hydrogels commonly used in clinical practice have good biocompatibility, their mechanical strength is generally insufficient, and they are prone to rupture when the wound contracts or moves, making it difficult to fit the dynamically changing wound surface; while synthetic materials have superior mechanical properties, but there is a potential risk of biotoxicity, and long-term use may inhibit cell migration and tissue regeneration. In addition, the existing technology for adding Chinese medicine ingredients mostly adopts simple physical mixing or direct loading of crude extracts, which makes the active ingredients easy to oxidize and inactivate, and the release is uncontrollable.

[0003] Therefore, there is an urgent need to develop a new type of hydrogel dressing that can achieve a triple balance of hydrogel mechanical properties, functional diversity, and drug sustained release through material design and process innovation while ensuring biosafety. Summary of the invention

[0004] In view of the above situation, the present invention provides a hydrogel dressing based on traditional Chinese medicine polysaccharides and a preparation method thereof. By introducing active polysaccharides from the traditional Chinese medicines Gastrodia elata, Bletilla striata and Astragalus membranaceus, and combining the dual curing design of photocuring and ionic crosslinking, a new multifunctional hydrogel dressing is developed. Relying on the design of the triple network structure and the dynamic responsive release mechanism, the mechanical properties of the gel and the utilization efficiency of the bioactive ingredients are significantly improved, and the defects of traditional dressings such as single function, mechanical fragility and uncontrollable release of traditional Chinese medicine ingredients are overcome. At the same time, multifunctional dressings such as antibacterial, anti-inflammatory, hemostasis and promotion of angiogenesis are achieved, providing an efficient and safe solution for the treatment of complex wounds.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows: The invention provides a hydrogel dressing based on traditional Chinese medicine polysaccharides. The hydrogel dressing comprises the following raw materials in parts by weight: 10-15 parts of gastrodia elata polysaccharide, 8-12 parts of bletilla striata polysaccharide, 5-8 parts of astragalus polysaccharide, 1-3 parts of nano silver-baicalin complex, 2-3 parts of methacrylic anhydride, 0.02-0.05 parts of VEGF (vascular endothelial growth factor), 0.4-1 parts of PLGA (polylactic acid-glycolic acid copolymer), 0.1-0.3 parts of Irgacure 2959 (photoinitiator), 20-30 parts of 5% (mass volume fraction) calcium chloride solution, 0.1 parts of polyvinyl alcohol and 100-170 parts of PBS (phosphate buffer, pH 7.4).

[0006] Furthermore, the nanosilver-baicalin complex comprises the following raw materials in parts by weight: 1-3 parts of silver nitrate, 5-10 parts of baicalin, 2-6 parts of 1% (mass volume fraction) sodium citrate solution and 1 part of PVP (polyvinyl pyrrolidone).

[0007] Furthermore, the purity of the Gastrodia elata polysaccharide, Bletilla striata polysaccharide and Astragalus membranaceus polysaccharide is 95%-98%.

[0008] Furthermore, the VEGF is VEGF165 subtype.

[0009] Furthermore, the polyvinyl alcohol is polyvinyl alcohol 1788, with a molecular weight of 75-80 kDa, a degree of polymerization of 1700, and a degree of alcoholysis of 87-89%.

[0010] The preparation method of the nano silver-baicalin complex comprises the following steps: S1: Weigh 1-3 parts of silver nitrate, add it to deionized water, stir and dissolve it, and prepare a 1% mass volume fraction silver nitrate solution; weigh 5-10 parts of baicalin, dissolve it in deionized water, and prepare a 1% mass volume fraction baicalin solution; S2: Heat the silver nitrate solution obtained in step S1 to 80° C. in a constant temperature magnetic stirrer, weigh 2-6 parts of 1% sodium citrate solution and slowly add it to the silver nitrate solution while stirring at a stirring speed of 100 rpm to obtain a reaction solution; S3: When the reaction solution of step S2 turns light yellow, weigh 1 portion of PVP and add it thereto, continue stirring for 10 min, then stop stirring and cool to room temperature to obtain a nanosilver solution; S4: mixing the baicalin solution obtained in step S1 with the nanosilver solution obtained in step S3, and placing the mixture in a constant temperature magnetic stirrer and stirring at 100 rpm for 2 h to obtain a nanosilver-baicalin crude complex; S5: The nanosilver-baicalin crude complex obtained in step S4 was centrifuged at 8000 rpm for 10 min, the supernatant was discarded, and the precipitate was collected. The precipitate was washed with deionized water for 3 times and then dried in an oven at 60° C. for 12 h to obtain a nanosilver-baicalin complex.

[0011] The present invention also provides a method for preparing a hydrogel dressing based on traditional Chinese medicine polysaccharides, which specifically comprises the following steps: Step 1: Weigh 10-15 parts of Gastrodia elata polysaccharide and dissolve it in deionized water to prepare a 5% mass volume fraction Gastrodia elata polysaccharide solution, weigh 2-3 parts of methacrylic anhydride and add it to the Gastrodia elata polysaccharide solution, stir it at 120 rpm in a constant temperature magnetic stirrer at 25°C for 12 h to obtain a crude reaction solution; Step 2: The crude reaction solution obtained in step 1 was transferred to a dialysis bag with a molecular weight of 3500 Da and dialyzed for 24 h. The liquid in the dialysis bag was transferred out to obtain a purified solution. 5-8 parts of astragalus polysaccharide and 0.1-0.3 parts of Irgacure 2959 were weighed and added to the purified solution. The mixture was stirred and dissolved to obtain a mixed solution. The mixed solution was placed in an ultraviolet crosslinker at a wavelength of 365 nm and 10 mW / cm 2 The primary gel was obtained by irradiating at 500 W for 5 min; Step 3: Weigh 8-12 parts of Bletilla striata polysaccharide and dissolve them in deionized water to prepare a 5% mass volume fraction Bletilla striata polysaccharide solution; weigh 20-30 parts of 5% calcium chloride solution, mix them with the Bletilla striata polysaccharide solution, and then add them to the primary gel obtained in step 2; gently stir and mix, and then let stand for 10 minutes to obtain a cross-linked gel; Step 4: Weigh 0.02-0.05 parts of VEGF and 0.4-1 parts of PLGA and dissolve them in dichloromethane at a mass ratio of PLGA to dichloromethane of 1:5 to obtain an oil phase; weigh 0.1 parts of polyvinyl alcohol and dissolve them in 90°C deionized water at a mass ratio of 1:100 to obtain an aqueous phase; slowly add the oil phase to the aqueous phase in a 40°C water bath to obtain a primary emulsion; emulsify the primary emulsion for 10 min using an ultrasonic emulsifier at a power of 200 W to obtain an emulsion; Step 5: The emulsion obtained in step 4 was placed on a constant temperature magnetic stirrer, stirred at 200 rpm for 4 h to volatilize the dichloromethane, centrifuged at 8000 rpm for 10 min, the supernatant was discarded to obtain a precipitate, and the precipitate was freeze-dried to obtain VEGF microspheres; Step 6: Weigh 100-170 parts of PBS, freeze-dry the cross-linked gel obtained in step 3 and add it to PBS, stir in a constant temperature magnetic stirrer at 40°C and 120 rpm for 30 min to dissolve, and obtain a hydrogel matrix. Weigh 1-3 parts of the nanosilver-baicalin complex and the VEGF microspheres obtained in step 5 and disperse them into the hydrogel matrix, continue stirring for 2 h, and let stand for 30 min to obtain a hydrogel dressing based on traditional Chinese medicine polysaccharides.

[0012] The beneficial effects achieved by the present invention are as follows: The hydrogel dressing based on Chinese medicine polysaccharides prepared by the present invention uses Gastrodia elata polysaccharide, Bletilla striata polysaccharide and Astragalus membranaceus polysaccharide as main raw materials, and successfully solves the problems of single function, insufficient mechanical properties and low utilization efficiency of active ingredients of Chinese medicine in traditional hydrogel dressings through the dual curing process of light curing-ion crosslinking. The modified methacrylic acid group in Gastrodia elata polysaccharide and Astragalus membranaceus polysaccharide form a primary network through ultraviolet light-induced free radical polymerization, and Bletilla striata polysaccharide and Ca²⁺ ion crosslinking construct a secondary network to form a triple network structure, which significantly improves the mechanical properties and biocompatibility of the hydrogel; at the same time, the loaded nanosilver-baicalin complex and VEGF microspheres realize the multifunctional integration of antibacterial, anti-inflammatory, hemostasis and angiogenesis through a dynamic responsive release mechanism, meeting the multi-stage treatment needs of complex wounds.

[0013] In addition, the present invention optimizes the preparation method of hydrogels, adopts the combined technology of light curing and ion cross-linking, solves the problem of insufficient mechanical properties of single cross-linking method, and gives the dressing injectability and in-situ gelling properties, adapting to irregular wounds; VEGF microspheres prepared by emulsification-solvent evaporation method achieve sustained release of vascular endothelial growth factor, significantly improving wound healing efficiency. Through the dual responsiveness design of pH / temperature, the hydrogel releases antibacterial components in the acidic environment of the wound, triggers gel contraction under high temperature conditions to accelerate hemostasis, realizes on-demand treatment, and avoids the problem of uncontrollable drug release in traditional dressings.

[0014] The present invention improves the performance and reliability of hydrogel dressings through unique material design, and provides a safer, more efficient and stable technical solution for the treatment of complex wounds. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention is a flow chart of the preparation of a hydrogel dressing based on traditional Chinese medicine polysaccharides; Figure 2 The compression modulus test results of the hydrogel dressings based on traditional Chinese medicine polysaccharides prepared in Examples 1-4 and the hydrogel dressing of Comparative Example 1; Figure 3 The swelling rate test results of the hydrogel dressings based on traditional Chinese medicine polysaccharides prepared in Examples 1-4 and the hydrogel dressing of Comparative Example 1; Figure 4 The antibacterial performance test results of the hydrogel dressings based on traditional Chinese medicine polysaccharides prepared in Examples 1-4 and the hydrogel dressing of Comparative Example 1; Figure 5 The cell proliferation rate test results of the hydrogel dressings based on traditional Chinese medicine polysaccharides prepared in Examples 1-4 and the hydrogel dressing of Comparative Example 1; Figure 6This is a scanning electron microscope image of the hydrogel dressing based on traditional Chinese medicine polysaccharides prepared in Example 1. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0017] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention. The preferred implementation methods and materials described herein are for demonstration purposes only and are not intended to limit the content of this application.

[0018] In the following embodiments, the preparation process of the hydrogel dressing based on traditional Chinese medicine polysaccharides is as follows: Figure 1 As shown, unless otherwise specified, all methods are conventional; the materials used in the following embodiments, unless otherwise specified, are new materials purchased from the market.

[0019] Example 1: This example provides a hydrogel dressing based on traditional Chinese medicine polysaccharides, comprising the following raw materials in parts by weight: 10 parts of Gastrodia elata polysaccharide, 10 parts of Bletilla striata polysaccharide, 5 parts of Astragalus polysaccharide, 1 part of nanosilver-baicalin complex, 2 parts of methacrylic anhydride, 0.02 parts of VEGF, 0.4 parts of PLGA, 0.1 parts of Irgacure 2959, 20 parts of 5% calcium chloride solution, 0.1 parts of polyvinyl alcohol and 100 parts of PBS.

[0020] The nano silver-baicalin complex comprises the following raw materials in parts by weight: 1 part of silver nitrate, 5 parts of baicalin, 2 parts of 1% sodium citrate solution and 1 part of PVP. The specific preparation method comprises the following steps: S1: Weigh 1 part of silver nitrate and add it to deionized water, stir and dissolve it to prepare a 1% mass volume fraction silver nitrate solution; weigh 5 parts of baicalin and dissolve it in deionized water to prepare a 1% mass volume fraction baicalin solution; S2: The silver nitrate solution obtained in step S1 is heated to 80° C. in a constant temperature magnetic stirrer, and 2 parts of 1% sodium citrate solution are weighed and slowly added into the silver nitrate solution while stirring at a stirring speed of 100 rpm to obtain a reaction solution; S3: When the reaction solution of step S2 turns light yellow, weigh 1 portion of PVP and add it thereto, continue stirring for 10 min, then stop stirring and cool to room temperature to obtain a nanosilver solution; S4: mixing the baicalin solution obtained in step S1 with the nanosilver solution obtained in step S3, and placing the mixture in a constant temperature magnetic stirrer and stirring at 100 rpm for 2 h to obtain a nanosilver-baicalin crude complex; S5: The nanosilver-baicalin crude complex obtained in step S4 was centrifuged at 8000 rpm for 10 min, the supernatant was discarded, and the precipitate was collected. The precipitate was washed with deionized water for 3 times and then dried in an oven at 60° C. for 12 h to obtain a nanosilver-baicalin complex.

[0021] This embodiment also provides a method for preparing a hydrogel dressing based on traditional Chinese medicine polysaccharides, which specifically comprises the following steps: Step 1: Weigh 10 parts of Gastrodia elata polysaccharide and dissolve it in deionized water to prepare a 5% mass volume fraction Gastrodia elata polysaccharide solution, weigh 2 parts of methacrylic anhydride and add it to the Gastrodia elata polysaccharide solution, stir it at 120 rpm in a constant temperature magnetic stirrer at 25°C for 12 hours to obtain a crude reaction solution; Step 2: The crude reaction solution obtained in step 1 was transferred to a dialysis bag with a molecular weight of 3500 Da and dialyzed for 24 h. The liquid in the dialysis bag was transferred out to obtain a purified solution. 5 parts of astragalus polysaccharide and 0.1 parts of Irgacure 2959 were weighed and added to the purified solution. The mixture was stirred and dissolved to obtain a mixed solution. The mixed solution was placed in an ultraviolet crosslinker at a wavelength of 365 nm and 10 mW / cm 2 The primary gel was obtained by irradiating at 500 W for 5 min; Step 3: Weigh 10 parts of Bletilla striata polysaccharide and dissolve them in deionized water to prepare a 5% mass volume fraction Bletilla striata polysaccharide solution; weigh 20 parts of 5% calcium chloride solution, mix them with the Bletilla striata polysaccharide solution and add them to the primary gel obtained in step 2; gently stir and mix well and let stand for 10 minutes to obtain a cross-linked gel; Step 4: Weigh 0.02 parts of VEGF and 0.4 parts of PLGA and dissolve them in dichloromethane at a mass ratio of PLGA to dichloromethane of 1:5 to obtain an oil phase; weigh 0.1 parts of polyvinyl alcohol and dissolve them in 90°C deionized water at a mass ratio of 1:100 to obtain an aqueous phase; slowly add the oil phase to the aqueous phase in a 40°C water bath to obtain a primary emulsion; emulsify the primary emulsion for 10 min using an ultrasonic emulsifier at a power of 200 W to obtain an emulsion; Step 5: The emulsion obtained in step 4 was placed on a constant temperature magnetic stirrer, stirred at 200 rpm for 4 h to volatilize the dichloromethane, centrifuged at 8000 rpm for 10 min, the supernatant was discarded to obtain a precipitate, and the precipitate was freeze-dried to obtain VEGF microspheres; Step 6: Weigh 100 parts of PBS, freeze-dry the cross-linked gel obtained in step 3 and add it to PBS, stir in a constant temperature magnetic stirrer at 40°C and 120 rpm for 30 min to dissolve, and obtain a hydrogel matrix. Weigh 1 part of the nanosilver-baicalin complex and the VEGF microspheres obtained in step 5 and disperse them into the hydrogel matrix, continue stirring for 2 h, and let stand for 30 min to obtain a hydrogel dressing based on traditional Chinese medicine polysaccharides.

[0022] Example 2: This example provides a hydrogel dressing based on traditional Chinese medicine polysaccharides, comprising the following raw materials in parts by weight: 12 parts of Gastrodia elata polysaccharide, 8 parts of Bletilla striata polysaccharide, 6 parts of Astragalus polysaccharide, 2 parts of nanosilver-baicalin complex, 2.5 parts of methacrylic anhydride, 0.04 parts of VEGF, 0.8 parts of PLGA, 0.2 parts of Irgacure 2959, 25 parts of 5% calcium chloride solution, 0.1 parts of polyvinyl alcohol and 140 parts of PBS.

[0023] The nano silver-baicalin complex comprises the following raw materials in parts by weight: 2 parts of silver nitrate, 8 parts of baicalin, 4 parts of 1% sodium citrate solution and 1 part of PVP. The specific preparation method comprises the following steps: S1: Weigh 2 parts of silver nitrate, add it into deionized water, stir and dissolve it, prepare a 1% mass volume fraction silver nitrate solution, weigh 8 parts of baicalin, dissolve it into deionized water, prepare a 1% mass volume fraction baicalin solution; S2: The silver nitrate solution obtained in step S1 is heated to 80° C. in a constant temperature magnetic stirrer, 4 parts of 1% sodium citrate solution are weighed and slowly added to the silver nitrate solution while stirring at a stirring speed of 100 rpm to obtain a reaction solution; S3: When the reaction solution of step S2 turns light yellow, weigh 1 portion of PVP and add it thereto, continue stirring for 10 min, then stop stirring and cool to room temperature to obtain a nanosilver solution; S4: mixing the baicalin solution obtained in step S1 with the nanosilver solution obtained in step S3, and placing the mixture in a constant temperature magnetic stirrer and stirring at 100 rpm for 2 h to obtain a nanosilver-baicalin crude complex; S5: The nanosilver-baicalin crude complex obtained in step S4 was centrifuged at 8000 rpm for 10 min, the supernatant was discarded, and the precipitate was collected. The precipitate was washed with deionized water for 3 times and then dried in an oven at 60° C. for 12 h to obtain a nanosilver-baicalin complex.

[0024] This embodiment also provides a method for preparing a hydrogel dressing based on traditional Chinese medicine polysaccharides, which specifically comprises the following steps: Step 1: Weigh 12 parts of Gastrodia elata polysaccharide and dissolve it in deionized water to prepare a 5% mass volume fraction Gastrodia elata polysaccharide solution, weigh 2.5 parts of methacrylic anhydride and add it to the Gastrodia elata polysaccharide solution, stir it at 120 rpm in a constant temperature magnetic stirrer at 25°C for 12 h to obtain a crude reaction solution; Step 2: The crude reaction solution obtained in step 1 was transferred to a dialysis bag with a molecular weight of 3500 Da and dialyzed for 24 h. The liquid in the dialysis bag was transferred out to obtain a purified solution. 6 parts of astragalus polysaccharide and 0.2 parts of Irgacure 2959 were weighed and added to the purified solution. The mixture was stirred and dissolved to obtain a mixed solution. The mixed solution was placed in an ultraviolet crosslinker at a wavelength of 365 nm and 10 mW / cm 2 The primary gel was obtained by irradiating at 500 W for 5 min; Step 3: Weigh 8 parts of Bletilla striata polysaccharide and dissolve them in deionized water to prepare a 5% mass volume fraction Bletilla striata polysaccharide solution; weigh 25 parts of 5% calcium chloride solution, mix them with the Bletilla striata polysaccharide solution and add them to the primary gel obtained in step 2; gently stir and mix well and let stand for 10 minutes to obtain a cross-linked gel; Step 4: Weigh 0.04 parts of VEGF and 0.8 parts of PLGA and dissolve them in dichloromethane at a mass ratio of PLGA to dichloromethane of 1:5 to obtain an oil phase; weigh 0.1 parts of polyvinyl alcohol and dissolve them in 90°C deionized water at a mass ratio of 1:100 to obtain an aqueous phase; slowly add the oil phase to the aqueous phase in a 40°C water bath to obtain a primary emulsion; emulsify the primary emulsion for 10 min using an ultrasonic emulsifier at a power of 200 W to obtain an emulsion; Step 5: The emulsion obtained in step 4 was placed on a constant temperature magnetic stirrer, stirred at 200 rpm for 4 h to volatilize the dichloromethane, centrifuged at 8000 rpm for 10 min, the supernatant was discarded to obtain a precipitate, and the precipitate was freeze-dried to obtain VEGF microspheres; Step 6: Weigh 140 parts of PBS, freeze-dry the cross-linked gel obtained in step 3 and add it to PBS, stir in a constant temperature magnetic stirrer at 40°C and 120 rpm for 30 min to dissolve, and obtain a hydrogel matrix. Weigh 2 parts of the nanosilver-baicalin complex and the VEGF microspheres obtained in step 5 and disperse them into the hydrogel matrix, continue stirring for 2 h, and let stand for 30 min to obtain a hydrogel dressing based on traditional Chinese medicine polysaccharides.

[0025] Example 3: This example provides a hydrogel dressing based on traditional Chinese medicine polysaccharides, comprising the following raw materials in parts by weight: 15 parts of Gastrodia elata polysaccharide, 10 parts of Bletilla striata polysaccharide, 8 parts of Astragalus polysaccharide, 3 parts of nanosilver-baicalin complex, 3 parts of methacrylic anhydride, 0.05 parts of VEGF, 1 part of PLGA, 0.3 parts of Irgacure 2959, 30 parts of 5% calcium chloride solution, 0.1 parts of polyvinyl alcohol and 150 parts of PBS.

[0026] The nano silver-baicalin complex comprises the following raw materials in parts by weight: 3 parts of silver nitrate, 10 parts of baicalin, 6 parts of 1% sodium citrate solution and 1 part of PVP. The specific preparation method comprises the following steps: S1: Weigh 3 parts of silver nitrate, add it into deionized water, stir and dissolve it, prepare a 1% mass volume fraction silver nitrate solution, weigh 10 parts of baicalin, dissolve it into deionized water, prepare a 1% mass volume fraction baicalin solution; S2: The silver nitrate solution obtained in step S1 is heated to 80° C. in a constant temperature magnetic stirrer, 6 parts of 1% sodium citrate solution are weighed and slowly added into the silver nitrate solution while stirring at a stirring speed of 100 rpm to obtain a reaction solution; S3: When the reaction solution of step S2 turns light yellow, weigh 1 portion of PVP and add it thereto, continue stirring for 10 min, then stop stirring and cool to room temperature to obtain a nanosilver solution; S4: mixing the baicalin solution obtained in step S1 with the nanosilver solution obtained in step S3, and placing the mixture in a constant temperature magnetic stirrer and stirring at 100 rpm for 2 h to obtain a nanosilver-baicalin crude complex; S5: The nanosilver-baicalin crude complex obtained in step S4 was centrifuged at 8000 rpm for 10 min, the supernatant was discarded, and the precipitate was collected. The precipitate was washed with deionized water for 3 times and then dried in an oven at 60° C. for 12 h to obtain a nanosilver-baicalin complex.

[0027] This embodiment also provides a method for preparing a hydrogel dressing based on traditional Chinese medicine polysaccharides, which specifically comprises the following steps: Step 1: Weigh 15 parts of Gastrodia elata polysaccharide and dissolve it in deionized water to prepare a 5% mass volume fraction Gastrodia elata polysaccharide solution, weigh 3 parts of methacrylic anhydride and add it to the Gastrodia elata polysaccharide solution, stir it at 120 rpm in a constant temperature magnetic stirrer at 25°C for 12 hours to obtain a crude reaction solution; Step 2: The crude reaction solution obtained in step 1 was transferred to a dialysis bag with a molecular weight of 3500 Da and dialyzed for 24 h. The liquid in the dialysis bag was transferred out to obtain a purified solution. 8 parts of astragalus polysaccharide and 0.3 parts of Irgacure 2959 were weighed and added to the purified solution. The mixture was stirred and dissolved to obtain a mixed solution. The mixed solution was placed in an ultraviolet crosslinker at a wavelength of 365 nm and 10 mW / cm 2 The primary gel was obtained by irradiating at 500 W for 5 min; Step 3: Weigh 10 parts of Bletilla striata polysaccharide and dissolve them in deionized water to prepare a 5% mass volume fraction Bletilla striata polysaccharide solution; weigh 30 parts of 5% calcium chloride solution, mix them with the Bletilla striata polysaccharide solution, and then add them to the primary gel obtained in step 2; gently stir and mix, and then let stand for 10 minutes to obtain a cross-linked gel; Step 4: Weigh 0.05 parts of VEGF and 1 part of PLGA and dissolve them in dichloromethane at a mass ratio of PLGA to dichloromethane of 1:5 to obtain an oil phase; weigh 0.1 parts of polyvinyl alcohol and dissolve them in 90°C deionized water at a mass ratio of 1:100 to obtain an aqueous phase; slowly add the oil phase to the aqueous phase in a 40°C water bath to obtain a primary emulsion; emulsify the primary emulsion for 10 min using an ultrasonic emulsifier at a power of 200 W to obtain an emulsion; Step 5: The emulsion obtained in step 4 was placed on a constant temperature magnetic stirrer, stirred at 200 rpm for 4 h to volatilize the dichloromethane, centrifuged at 8000 rpm for 10 min, the supernatant was discarded to obtain a precipitate, and the precipitate was freeze-dried to obtain VEGF microspheres; Step 6: Weigh 150 parts of PBS, freeze-dry the cross-linked gel obtained in step 3 and add it to PBS, stir in a constant temperature magnetic stirrer at 40°C and 120 rpm for 30 min to dissolve, and obtain a hydrogel matrix. Weigh 3 parts of nanosilver-baicalin complex and VEGF microspheres obtained in step 5 and disperse them into the hydrogel matrix, continue stirring for 2 h, and let stand for 30 min to obtain a hydrogel dressing based on traditional Chinese medicine polysaccharides.

[0028] Example 4: This example provides a hydrogel dressing based on traditional Chinese medicine polysaccharides, comprising the following raw materials in parts by weight: 15 parts of Gastrodia elata polysaccharide, 12 parts of Bletilla striata polysaccharide, 8 parts of Astragalus polysaccharide, 3 parts of nanosilver-baicalin complex, 3 parts of methacrylic anhydride, 0.05 parts of VEGF, 1 part of PLGA, 0.3 parts of Irgacure 2959, 30 parts of 5% calcium chloride solution, 0.1 parts of polyvinyl alcohol and 170 parts of PBS.

[0029] The nano silver-baicalin complex comprises the following raw materials in parts by weight: 2 parts of silver nitrate, 7 parts of baicalin, 2 parts of 1% sodium citrate solution and 1 part of PVP. The specific preparation method comprises the following steps: S1: Weigh 2 parts of silver nitrate, add it into deionized water, stir and dissolve it, prepare a 1% mass volume fraction silver nitrate solution, weigh 7 parts of baicalin, dissolve it into deionized water, prepare a 1% mass volume fraction baicalin solution; S2: The silver nitrate solution obtained in step S1 is heated to 80° C. in a constant temperature magnetic stirrer, and 2 parts of 1% sodium citrate solution are weighed and slowly added into the silver nitrate solution while stirring at a stirring speed of 100 rpm to obtain a reaction solution; S3: When the reaction solution of step S2 turns light yellow, weigh 1 portion of PVP and add it thereto, continue stirring for 10 min, then stop stirring and cool to room temperature to obtain a nanosilver solution; S4: mixing the baicalin solution obtained in step S1 with the nanosilver solution obtained in step S3, and placing the mixture in a constant temperature magnetic stirrer and stirring at 100 rpm for 2 h to obtain a nanosilver-baicalin crude complex; S5: The nanosilver-baicalin crude complex obtained in step S4 was centrifuged at 8000 rpm for 10 min, the supernatant was discarded, and the precipitate was collected. The precipitate was washed with deionized water for 3 times and then dried in an oven at 60° C. for 12 h to obtain a nanosilver-baicalin complex.

[0030] This embodiment also provides a method for preparing a hydrogel dressing based on traditional Chinese medicine polysaccharides, which specifically comprises the following steps: Step 1: Weigh 15 parts of Gastrodia elata polysaccharide and dissolve it in deionized water to prepare a 5% mass volume fraction Gastrodia elata polysaccharide solution, weigh 3 parts of methacrylic anhydride and add it to the Gastrodia elata polysaccharide solution, stir it at 120 rpm in a constant temperature magnetic stirrer at 25°C for 12 hours to obtain a crude reaction solution; Step 2: The crude reaction solution obtained in step 1 was transferred to a dialysis bag with a molecular weight of 3500 Da and dialyzed for 24 h. The liquid in the dialysis bag was transferred out to obtain a purified solution. 8 parts of astragalus polysaccharide and 0.3 parts of Irgacure 2959 were weighed and added to the purified solution. The mixture was stirred and dissolved to obtain a mixed solution. The mixed solution was placed in an ultraviolet crosslinker at a wavelength of 365 nm and 10 mW / cm 2 The primary gel was obtained by irradiating at 500 W for 5 min; Step 3: Weigh 12 parts of Bletilla striata polysaccharide and dissolve them in deionized water to prepare a 5% mass volume fraction Bletilla striata polysaccharide solution; weigh 30 parts of 5% calcium chloride solution, mix them with the Bletilla striata polysaccharide solution, and then add them to the primary gel obtained in step 2; gently stir and mix, and then let stand for 10 minutes to obtain a cross-linked gel; Step 4: Weigh 0.05 parts of VEGF and 1 part of PLGA and dissolve them in dichloromethane at a mass ratio of PLGA to dichloromethane of 1:5 to obtain an oil phase; weigh 0.1 parts of polyvinyl alcohol and dissolve them in 90°C deionized water at a mass ratio of 1:100 to obtain an aqueous phase; slowly add the oil phase to the aqueous phase in a 40°C water bath to obtain a primary emulsion; emulsify the primary emulsion for 10 min using an ultrasonic emulsifier at a power of 200 W to obtain an emulsion; Step 5: The emulsion obtained in step 4 was placed on a constant temperature magnetic stirrer, stirred at 200 rpm for 4 h to volatilize the dichloromethane, centrifuged at 8000 rpm for 10 min, the supernatant was discarded to obtain a precipitate, and the precipitate was freeze-dried to obtain VEGF microspheres; Step 6: Weigh 170 parts of PBS, freeze-dry the cross-linked gel obtained in step 3 and add it to PBS, stir in a constant temperature magnetic stirrer at 40°C and 120 rpm for 30 min to dissolve, and obtain a hydrogel matrix. Weigh 3 parts of nanosilver-baicalin complex and VEGF microspheres obtained in step 5 and disperse them into the hydrogel matrix, continue stirring for 2 h, and let stand for 30 min to obtain a hydrogel dressing based on traditional Chinese medicine polysaccharides.

[0031] Comparative Example 1 is a hydrogel dressing purchased on the market and prepared from sodium carboxymethyl cellulose, calcium alginate and purified water.

[0032] Mechanical properties inspection (compression modulus) The hydrogel dressings prepared in Examples 1-4 and Comparative Example 1 were respectively cut into cylinders with a diameter of 10 mm and a height of 5 mm, placed on a universal material testing machine, and the compression rate was set to 1 mm / min. The compression was performed to 50% strain, and the stress-strain curve was recorded. The compression modulus (the slope of the initial linear segment) was calculated. The above operation was repeated 3 times, and the results were averaged. Figure 2 .

[0033] Swelling performance investigation After freeze-drying, 10 mg (dry weight, W0) of the hydrogel dressings prepared in Examples 1-4 and Comparative Example 1 were weighed respectively and placed in 50 mL PBS (pH 7.4). After standing at room temperature for 24 hours, the dressings were taken out and the surface moisture was absorbed with filter paper and the wet weight (Wₜ) was weighed. The swelling rate was calculated as follows: Swelling rate (%) = (W t -W0) / W0×100%, repeat 3 times, take the average value, the result is shown in Figure 3 .

[0034] Antibacterial performance investigation The hydrogel samples prepared in Examples 1-4 and Comparative Example 1 were cut into discs with a diameter of 6 mm, and were respectively pasted on LB agar plates inoculated with Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922). After incubation at 37°C for 24 hours, the diameter of the inhibition zone was measured. The above operation was repeated 3 times and the average value was taken. The results are shown in Table 1. Figure 4 .

[0035] Cytocompatibility study The hydrogel dressings prepared in Examples 1-4 and Comparative Example 1 were respectively co-cultured with L929 mouse fibroblasts. When L929 was in the logarithmic growth phase, they were inoculated in a 96-well plate at 2000 cells / well. After the cells adhered to the wall, the hydrogel dressings prepared in Examples 1-4 and Comparative Example 1 were diluted 100 times with DMEM single culture medium, and 100 μL of the diluted gel was respectively taken in a 96-well plate. After 1 day, the absorbance (A) at 450 nm was detected by CCK-8 method, and the cell proliferation rate was calculated. The wells without cells were used as blank groups, and the wells with DMEM single culture medium were used as control groups. The cell proliferation rate (%) = (A 实验组 -A 空白组 ) / (A 对照组 -A 空白组 )×100%, see the results Figure 5 .

[0036] Microscopic morphology observation The hydrogel dressing prepared in Example 1 was fixed on a sample plate using a conductive adhesive, and gold was plated using a sputtering coating machine. The morphology of the microneedles was examined using a scanning electron microscope. The results are as follows: Figure 6 shown.

[0037] Figure 2 The compression modulus results show that compared with the traditional hydrogel dressing of Comparative Example 1, the hydrogel dressing based on traditional Chinese medicine polysaccharides provided by the present invention has good mechanical properties and a stable structure.

[0038] Figure 3 The gel swelling test results show that the hydrogel dressings based on traditional Chinese medicine polysaccharides prepared in Examples 1-4 have stronger water absorption, which is beneficial for absorbing tissue fluid and blood exuded from the wound surface.

[0039] Figure 4 The antibacterial performance results show that the components such as the Chinese herbal polysaccharides and VEGF in the hydrogel dressings based on Chinese herbal polysaccharides prepared in Examples 1-4 can effectively inhibit the growth of Staphylococcus aureus and Escherichia coli, effectively reduce secondary infection of skin wounds, and accelerate wound healing.

[0040] Figure 5 The cell proliferation results showed that the hydrogel dressing based on Chinese medicine polysaccharides can provide certain nutrients and growth factors for cell growth, and can promote cell growth and proliferation.

[0041] Figure 6 The scanning electron microscope micrograph shows that the hydrogel dressing based on traditional Chinese medicine polysaccharides prepared in Example 1 has a cross-linked gel network structure, and has certain micromechanical strength and controlled drug release performance.

[0042] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0043] The present invention and its implementation methods are described above, which is not restrictive. The drawings are only one of the implementation methods of the present invention, and the actual application is not limited thereto. In short, if ordinary technicians in the field are inspired by it and design methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A hydrogel dressing based on traditional Chinese medicine polysaccharides, characterized in that: The hydrogel dressing comprises the following raw materials in parts by weight: 10-15 parts of Gastrodia elata polysaccharide, 8-12 parts of Bletilla striata polysaccharide, 5-8 parts of Astragalus polysaccharide, 1-3 parts of nanosilver-baicalin complex, 2-3 parts of methacrylic anhydride, 0.02-0.05 parts of VEGF, 0.4-1 parts of PLGA, 0.1-0.3 parts of Irgacure 2959, 20-30 parts of 5% calcium chloride solution, 0.1 parts of polyvinyl alcohol and 100-170 parts of PBS; The nano silver-baicalin complex comprises the following raw materials in parts by weight: 1-3 parts of silver nitrate, 5-10 parts of baicalin, 2-6 parts of 1% sodium citrate solution and 1 part of PVP.

2. A hydrogel dressing based on traditional Chinese medicine polysaccharides according to claim 1, characterized in that: The specific preparation method of the nano silver-baicalin complex comprises the following steps: S1: weigh silver nitrate and baicalin to prepare silver nitrate solution and baicalin solution respectively; S2: Weigh 1% sodium citrate solution and add it to the silver nitrate solution to obtain a reaction solution; S3: When the reaction solution changes color, weigh PVP and add it to obtain a nanosilver solution; S4: mixing and stirring the baicalin solution and the nanosilver solution to obtain a nanosilver-baicalin crude complex; S5: centrifuging the crude nanosilver-baicalin complex to obtain a precipitate, and drying the precipitate to obtain the nanosilver-baicalin complex.

3. A hydrogel dressing based on traditional Chinese medicine polysaccharides according to claim 2, characterized in that: In step S1, the concentrations of the silver nitrate solution and the baicalin solution are both 1% by mass volume fraction; In step S3, the color change process is that the reaction liquid changes to light yellow.

4. The hydrogel dressing based on traditional Chinese medicine polysaccharides according to claim 1, characterized in that: The purity of the Gastrodia elata polysaccharide, Bletilla striata polysaccharide and Astragalus membranaceus polysaccharide is 95%-98%.

5. The hydrogel dressing based on traditional Chinese medicine polysaccharides according to claim 1, characterized in that: The VEGF is the VEGF165 subtype.

6. The hydrogel dressing based on traditional Chinese medicine polysaccharides according to claim 1, characterized in that: The polyvinyl alcohol is polyvinyl alcohol 1788, with a molecular weight of 75-80 kDa, a degree of polymerization of 1700, and a degree of alcoholysis of 87-89%.

7. A method for preparing a hydrogel dressing based on traditional Chinese medicine polysaccharides according to any one of claims 1 to 6, characterized in that: The specific preparation method is as follows: Step 1: Weigh Gastrodia elata polysaccharide to prepare Gastrodia elata polysaccharide solution, weigh methacrylic anhydride and add it into the solution. Obtaining a crude reaction solution; Step 2: dialyze the crude reaction solution to obtain a purified solution, weigh astragalus polysaccharide and Irgacure 2959 and add them to the purified solution to obtain a mixed solution, and irradiate with ultraviolet light to obtain a primary gel; Step 3: Weighing Bletilla striata polysaccharide to prepare Bletilla striata polysaccharide solution, weighing 5% calcium chloride solution and mixing with the Bletilla striata polysaccharide solution, and then adding to the primary gel to obtain a cross-linked gel; Step 4: Weigh VEGF and PLGA to dissolve to obtain an oil phase, weigh polyvinyl alcohol to dissolve to obtain an aqueous phase, and add the oil phase to the aqueous phase for emulsification to obtain an emulsion; Step 5: stirring and centrifuging the emulsion to obtain a precipitate, and freeze-drying the precipitate to obtain VEGF microspheres; Step 6: Weigh PBS, freeze-dry the cross-linked gel and dissolve it in PBS to obtain a hydrogel matrix, weigh the nanosilver-baicalin complex and the VEGF microspheres obtained in step 5 and disperse them into the hydrogel matrix to obtain a hydrogel dressing based on traditional Chinese medicine polysaccharides.

8. The method for preparing a hydrogel dressing based on traditional Chinese medicine polysaccharides according to claim 7, characterized in that: In step 2, the dialysis bag used in the dialysis process has a specification of 3500 Da, and the ultraviolet light irradiation conditions are 365 nm wavelength, 10 mW / cm 2 Irradiate at 500W for 5 min; In step 4, the solvent used in the oil phase is dichloromethane, the solvent used in the water phase is deionized water, the mass ratio of PLGA to dichloromethane is 1:5, and the mass ratio of polyvinyl alcohol to deionized water is 1:100.

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