A patterned skin dressing with antioxidant, antibacterial and moisturizing properties and a preparation method thereof

Abstract

The present invention belongs to the technical field of skin dressings. The present invention provides a patterned skin dressing with antioxidant, antibacterial and moisturizing properties and a preparation method thereof, the preparation method comprising the following steps: (1) preparing a polymer solution with a mixture of chitosan and polyvinyl alcohol as a shell solution; mixing active ingredients into a polyethylene glycol aqueous solution as a core solution; (2) using a glass plate with a groove pattern as a receiving plate, coaxially electrospinning the shell solution and the core solution obtained in step (1) to prepare a fiber membrane to obtain the skin dressing; wherein the active ingredients include vitamin E, celery seed water extract and amaranth water extract in a weight ratio of 1:1:1 to 2. The dressing obtained by the present invention has excellent antioxidant, antibacterial and moisturizing properties, can also significantly shorten the healing time of burn wounds, and has good industrial application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of skin dressings, and in particular relates to a patterned skin dressing with antioxidant, antibacterial and moisturizing properties and a preparation method thereof. Background Art

[0002] Burns are one of the common traumas, and dressings are often needed in clinical treatment of burns. Generally speaking, dressings include dry dressings and wet dressings. Common dry dressings are gauze, and wet dressings include hydrogels, fiber membranes, etc. Wet dressings generally used for burns are only used to provide a moist environment to reduce the pain caused by dressing changes to patients; a few dressings can provide anti-inflammatory and antibacterial effects and shorten the wound healing time.

[0003] At present, people have made a lot of achievements in the research and development of dressings specifically for burns, such as Xiao Changshuan et al. [1] The compound phellodendron chinense liquid was combined with moist healing dressing to obtain a dressing for treating deep second-degree burns in the elderly that are difficult to heal; Li Zhaopei [2] et al. used compound lithospermum oil nanosilver for the treatment of burns; Zhang Yan [3] et al. used mesh xenogeneic acellular dermal matrix dressing combined with medical activated carbon dressing for the treatment of pediatric burns.

[0004] In the prior art of this field, there are few reports on skin dressings that can take into account antioxidant, antibacterial and moisturizing properties. The reason is that it is relatively difficult to find new substances or material compositions that have high antioxidant and antibacterial properties. In addition, if existing skin dressings need to obtain good moisturizing properties, they often require more complicated designs, which increases the production cost of the dressings. At the same time, there is a lack of available theoretical guidance for finding new substances that can be used to promote the healing of burn wounds.

[0005] Therefore, developing a skin dressing with excellent antioxidant, antibacterial, moisturizing properties and that can accelerate the healing of burn wounds is a challenging research topic.

[0006] [1] Xiao Changshuan, Liu Yaping, Wang Hao, Bao Haiyang, Yang Jingzhe, Chen Hongyu. Clinical observation of compound phellodendron liquid combined with moist healing dressing in the treatment of deep second-degree burns and refractory wounds in the elderly[J]. Chinese Journal of Aesthetic Medicine, 2024.

[0007] [2] Li Zhaopei, Wang Zhouzhu. Efficacy of compound lithospermum oil nanosilver medical antibacterial dressing in the treatment of deep second-degree burns[J]. China Medical Guide, 2024(28).

[0008] [3] Zhang Yan, Lai Qinghong, Sun Junfeng, et al. Evaluation of the therapeutic effect of improved burn eschar removal + mesh xenogeneic acellular dermal matrix dressing combined with activated carbon dressing on deep second-degree burn wounds in children[J]. Medical Theory and Practice, 2024, 37(20):3513-3516.DOI:10.19381 / j.issn.1001-7585.2024.20.033. Summary of the invention

[0009] In view of the defects of the prior art, the object of the present invention is to provide a skin dressing having excellent antioxidant, antibacterial and moisturizing properties and a preparation method thereof, and the skin dressing can significantly improve the wound healing rate after burns.

[0010] In order to achieve the above object, the present invention provides the following technical solutions:

[0011] A method for preparing an antioxidant, antibacterial and moisturizing patterned skin dressing, the preparation method comprising the following steps:

[0012] (1) preparing a polymer solution with a mixture of chitosan and polyvinyl alcohol at a weight ratio of 3 to 5:1 as a shell layer solution; mixing the active ingredient into the polyethylene glycol aqueous solution as a core layer solution;

[0013] (2) using a glass plate with a groove pattern as a receiving plate, a coaxial needle as a nozzle, and a dual-channel propulsion pump to control the flow rate of the shell layer liquid and the core layer liquid, and coaxially electrospinning the shell layer solution and the core layer solution obtained in step (1) to prepare a fiber membrane, thereby obtaining the skin dressing;

[0014] Wherein, in step (1), the active ingredients include vitamin E, celery seed water extract and amaranth water extract in a weight ratio of 1:1:1-2.

[0015] The research of the present invention was completed with the support of the special project of the Medical Beauty Research Center of Chengdu Medical College (project number: 22YM009). As shown in Experimental Example 1 of the present invention, the present invention investigated the effect of active substances in different core layer solutions on the antibacterial properties of the obtained dressing during the research process. The inventors found that when celery seed water extract or amaranth water extract was not added, the antibacterial properties of the obtained dressing were poor.

[0016] In the prior art, people have done a lot of research on celery seed water extracts. The inventor of CN112716989B extracted celery seeds with an organic solvent and then extracted them with an ethanol-water solution. The obtained extract has health effects such as reducing blood uric acid, relieving and treating gout, and preventing gout. For example, the inventor of CN107362194B found that after extracting celery seeds and Sophora japonica seeds with alcohol solvents, the obtained extract can effectively prevent or treat gout caused by hyperuricemia. In addition to the efficacy in treating high uric acid, people have also found that celery seed oil prepared using celery seeds as raw materials has antibacterial effects. For example, the celery seed oil obtained from Chinese patent application CN114317102A has antioxidant and antibacterial effects. However, there are few studies on the antibacterial properties of celery seed water extracts.

[0017] The inventors of the present invention have found that the antibacterial property of the resulting dressing can be significantly enhanced by mixing the celery seed water extract with the amaranth water extract, which indicates that the two have a synergistic effect in antibacterial properties.

[0018] In addition, as far as the inventors know, there are few studies on the efficacy of amaranth water extract in the prior art, and people are more concerned about amaranth alcohol extract. For example, Chinese patent CN110711208B found that after amaranth was extracted with ethanol and then subjected to specific extraction and purification steps, the resulting extract has the effect of lowering blood uric acid.

[0019] On the basis of the above, the core layer solution designed in the present invention when preparing the dressing also contains vitamin E, which can play a corresponding antioxidant role. It is worth noting that, as shown in Experimental Example 2 of the present invention, the amaranth extract can also produce obvious synergistic effects with vitamin E.

[0020] The most surprising thing is that the inventors found that the dressing obtained by the present invention can significantly improve the wound healing rate after burns. Generally speaking, the moisturizing, antibacterial and antioxidant environment provided by the dressing helps to prevent wound infection and reduce the pain of the patient, but the effect on wound healing is often limited. In order to accelerate healing, it is usually necessary to add drugs that can promote wound healing. However, as shown in Experimental Example 4 of the present invention, the dressing obtained by Examples 1-3 of the present invention can significantly promote the healing of wounds, and is even significantly better than the known active ingredient Centella asiatica total glycosides that promotes the recovery of burn skin; at the same time, as shown in the relevant comparative examples, whether celery seed water extract is added has little effect on the wound healing rate. It can be seen that the celery seed water extract and the amaranth water extract in the present invention play a synergistic role in the antibacterial and antioxidant properties of the dressing. In addition, the amaranth water extract in the dressing has a promoting effect on the recovery of burn skin.

[0021] In summary, the contribution of the present invention to the prior art is that it not only provides an environment with good antibacterial and antioxidant properties to prevent wound infection; it also provides good moisturizing properties for the dressing in a relatively simple way, which is beneficial for patients to reduce discomfort; more importantly, the provided dressing can significantly accelerate the healing of the wound surface, which is beneficial for the recovery of burn wounds.

[0022] Preferably, the weight ratio of chitosan to polyvinyl alcohol is 4:1.

[0023] Preferably, when preparing the polymer solution with a mixture of chitosan and polyvinyl alcohol, chitosan and polyvinyl alcohol are dissolved in acetic acid solution, and the weight concentration of the obtained polymer solution is 1%.

[0024] Preferably, in the core layer solution, the weight concentration of polyethylene glycol is 25%.

[0025] Preferably, among the active ingredients added to the core layer solution, the weight concentration of vitamin E in the core layer solution is 1%, the weight concentration of celery seed water extract in the core layer solution is 1%, and the weight concentration of amaranth extract in the core layer solution is 2%.

[0026] Preferably, the groove-patterned glass plate is obtained by silver plating on a non-conductive glass substrate by direct current magnetron sputtering. In the groove-patterned glass plate, the groove patterning is formed by a stripe pattern array, and the width of the stripe pattern is 200 μm.

[0027] Preferably, during coaxial electrospinning, the voltage is 15 kV, the core layer solution feeding rate is 0.5 ml / h, the shell layer solution feeding rate is 2 ml / h, and the distance from the needle to the receiving plate is 12 cm.

[0028] Preferably, in step (2), after preparing the fiber membrane, a treatment step of removing residual solvent in the fiber membrane is also included; when performing the treatment step of removing residual solvent in the fiber membrane, the obtained fiber membrane is placed in a vacuum drying oven at 35°C and dried for 6 hours.

[0029] Preferably, the amaranth extract is prepared by the following method: take the whole amaranth herb, wash and cut it into pieces, add water at a solid-liquid weight ratio of 1:10, extract at 90°C for 2 hours, and filter to obtain the filtrate; then add water to the filter residue at a solid-liquid weight ratio of 1:10, extract at 90°C for another 2 hours, and filter to obtain the filtrate; combine the filtrates obtained from the two extractions, perform rotary evaporation, and obtain a dry powder; the celery seed water extract is prepared by the following method: take celery seeds, wash them, add water at a solid-liquid weight ratio of 1:15, extract at 90°C for 2 hours, and filter to obtain the filtrate; then add water to the filter residue at a solid-liquid weight ratio of 1:15, extract at 90°C for another 2 hours, and filter to obtain the filtrate; combine the filtrates obtained from the two extractions, perform rotary evaporation, and obtain a dry powder.

[0030] Beneficial effects of the present invention:

[0031] The dressing obtained by the present invention has excellent anti-oxidation, antibacterial and moisturizing properties, can also significantly shorten the healing time of burn wounds, and has good industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The diagram is a schematic diagram of the preparation of the receiving plate used in the present invention and a SEM image of the resulting dressing; wherein, part a is a schematic diagram of the preparation of the receiving plate; parts b and c are SEM images of the resulting dressing at different scales. DETAILED DESCRIPTION

[0033] The present invention is described in detail below through examples. It is necessary to point out that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by technical personnel in this field based on the above invention content still fall within the scope of protection of the present invention.

[0034] Example 1

[0035] 1. Raw materials and equipment

[0036] (1) Raw materials

[0037] Chitosan (CS for short): Sichuan Chengzhu Biotechnology Co., Ltd.; polyvinyl alcohol (PVA for short): Chengdu Blue Whale Technology Co., Ltd.; polyethylene glycol (PEG for short): polyethylene glycol 400, Sichuan Baichun Technology Co., Ltd.; vitamin E: Sichuan Jingcui Tiancheng Pharmaceutical Technology Co., Ltd.

[0038] Amaranth water extract:

[0039] Take the whole herb of Amaranth available on the market, wash it and cut it into pieces, add water at a solid-liquid weight ratio of 1:10, extract it at 90°C for 2 hours, and filter out the filtrate; then add water to the residue at a solid-liquid weight ratio of 1:10, extract it at 90°C for another 2 hours, and filter out the filtrate; combine the filtrates obtained from the two extractions, perform rotary evaporation, and obtain a dry powder.

[0040] Celery Seed Water Extract:

[0041] Take commercially available celery seeds, wash them, add water at a solid-liquid weight ratio of 1:15, extract at 90°C for 2 hours, and filter the filtrate; then add water to the residue at a solid-liquid weight ratio of 1:15, extract at 90°C for another 2 hours, and filter the filtrate; combine the filtrates obtained from the two extractions, perform rotary evaporation, and obtain a dry powder.

[0042] (2) Device

[0043] Silver-coated "groove-gully" patterned glass plate: the operation steps are as follows Figure 1 As shown in part a, the specific design is as follows: TannerL-edit software is used to design multiple 6.0×6.0 mm 2 The micro-regions consist of squares, each of which is a strip array consisting of multiple strips and gaps. The width of the strip pattern is 200 μm, and the width of the interval between the strip patterns is also set to 200 μm. The computer-designed pattern data is input into a high-resolution electron beam lithography system to prepare a photolithography mask. A DC magnetron sputtering machine is used to deposit a 15×15 cm 2 A non-conductive glass substrate is plated with a layer of metallic silver, a layer of photoresist is coated thereon, and then covered with a photolithography mask. A photolithography machine is used for exposure, the glass substrate is cleaned to remove the exposed photoresist, the silver exposed area is corroded, and the excess photoresist is finally removed. An electrospinning receiving plate with patterned micro-areas can be formed on the glass substrate.

[0044] 2. Preparation of dressing:

[0045] (1) CS and PVA in a weight ratio of 4:1 were dissolved in acetic acid solution to prepare a polymer solution with a concentration of 1% (w%). The solution was stirred on a constant temperature magnetic stirrer for 4 h until the polymer was completely dissolved and the final solution was a clear light orange-yellow color, which served as the shell liquid.

[0046] (2) Using deionized water as the solvent, vitamin E, celery seed water extract, amaranth water extract and PEG solution were blended to obtain an aqueous solution in which PEG accounted for 25% (w%), vitamin E accounted for 1% (w%), celery seed water extract accounted for 1% (w%) and amaranth water extract accounted for 2% (w%) as the core layer liquid.

[0047] (3) The electrospinning parameters were set as follows: a fixed voltage of 15 kV, a dual-channel electrospinning propulsion pump was used to control the liquid flow rates of the shell layer and the core layer respectively, the shell layer syringe liquid feeding rate was 2 ml / h, and the core layer syringe liquid feeding rate was 0.5 ml / h; a coaxial needle was used as the nozzle, and a silver-coated "groove-gully" patterned glass plate was used as the receiving plate, and the distance between the needle and the receiving plate was 12 cm; the prepared nanofibers were placed in a vacuum drying oven at 35 °C for 6 h to remove the residual solvent to obtain a dressing. Figure 1 Part b in the middle is a scanning electron microscope image of the patterned nanofiber membrane prepared on a patterned receiving plate using electrospinning technology. It can be seen that the fiber membrane has a clear "groove" pattern, and the grooves are clearly spaced apart. The spacing and width of the grooves are relatively uniform. The magnification is 40 times. Figure 1 The c part is correct Figure 1 From the further magnified scanning electron microscope image of part b, it can be seen that the fiber membrane structure is uniform and dense. The density of the "gully" is higher than that of the "groove", and the grayscale is darker, which can clearly distinguish the structures of the two patterns.

[0048] Example 2

[0049] The raw materials and apparatus are the same as those in Example 1.

[0050] Dressing preparation:

[0051] (1) CS and PVA in a weight ratio of 3:1 were dissolved in acetic acid solution to prepare a polymer solution with a concentration of 1% (w%). The solution was stirred on a constant temperature magnetic stirrer for 4 h until the polymer was completely dissolved and the final solution was a clear light orange-yellow color, which served as the shell liquid.

[0052] (2) Using deionized water as the solvent, vitamin E, celery seed water extract, amaranth water extract and PEG solution were blended to obtain an aqueous solution with PEG accounting for 25% (w%), vitamin E accounting for 1% (w%), celery seed water extract accounting for 1% (w%) and amaranth water extract accounting for 1.5% (w%) as the core layer liquid.

[0053] (3) The electrospinning parameters were set as follows: a fixed voltage of 15 kV, a dual-channel electrospinning propulsion pump was used to control the liquid flow rates of the shell layer and the core layer respectively, the shell layer syringe liquid feeding rate was 2 ml / h, and the core layer syringe liquid feeding rate was 0.5 ml / h; a coaxial needle was used as the nozzle, and a silver-coated "groove-gully" patterned glass plate was used as the receiving plate, and the distance between the needle and the receiving plate was 12 cm; the prepared nanofibers were placed in a vacuum drying oven at 35 °C for 6 h to remove the residual solvent to obtain a dressing.

[0054] Example 3

[0055] The raw materials and apparatus are the same as those in Example 1.

[0056] Dressing preparation:

[0057] (1) CS and PVA in a weight ratio of 5:1 were dissolved in acetic acid solution to prepare a polymer solution with a concentration of 1% (w%). The solution was stirred on a constant temperature magnetic stirrer for 4 h until the polymer was completely dissolved and the final solution was a clear light orange-yellow color, which served as the shell liquid.

[0058] (2) Using deionized water as the solvent, vitamin E, celery seed water extract, amaranth water extract and PEG solution were blended to obtain an aqueous solution with PEG accounting for 25% (w%), vitamin E accounting for 1% (w%), celery seed water extract accounting for 1% (w%) and amaranth water extract accounting for 1% (w%) as the core layer liquid.

[0059] (3) The electrospinning parameters were set as follows: a fixed voltage of 15 kV, a dual-channel electrospinning propulsion pump was used to control the liquid flow rates of the shell layer and the core layer respectively, the shell layer syringe liquid feeding rate was 2 ml / h, and the core layer syringe liquid feeding rate was 0.5 ml / h; a coaxial needle was used as the nozzle, and a silver-coated "groove-gully" patterned glass plate was used as the receiving plate, and the distance between the needle and the receiving plate was 12 cm; the prepared nanofibers were placed in a vacuum drying oven and dried at 35 °C for 6 h to remove the residual solvent to obtain a dressing.

[0060] Comparative Example 1

[0061] The technical solution of this comparative example is different from that of Example 1, except that the core layer liquid does not contain the amaranth water extract, and the rest is the same as that of Example 1. In addition, the raw materials used in this comparative example refer to those of Example 1.

[0062] The specific technical solutions are as follows:

[0063] Dressing preparation:

[0064] (1) CS and PVA in a weight ratio of 4:1 were dissolved in acetic acid solution to prepare a polymer solution with a concentration of 1% (w%). The solution was stirred on a constant temperature magnetic stirrer for 4 h until the polymer was completely dissolved and the final solution was a clear light orange-yellow color, which served as the shell liquid.

[0065] (2) Using deionized water as the solvent, vitamin E, celery seed aqueous extract, and PEG solution were blended to obtain an aqueous solution in which PEG accounted for 25% (w%), vitamin E accounted for 1% (w%), and celery seed aqueous extract accounted for 1% (w%), which was used as the core layer liquid.

[0066] (3) The electrospinning parameters were set as follows: a fixed voltage of 15 kV, a dual-channel electrospinning propulsion pump was used to control the liquid flow rates of the shell layer and the core layer respectively, the shell layer syringe liquid feeding rate was 2 ml / h, and the core layer syringe liquid feeding rate was 0.5 ml / h; a coaxial needle was used as the nozzle, and a silver-coated "groove-gully" patterned glass plate was used as the receiving plate, and the distance between the needle and the receiving plate was 12 cm; the prepared nanofibers were placed in a vacuum drying oven and dried at 35 °C for 6 h to remove the residual solvent to obtain a dressing.

[0067] Comparative Example 2

[0068] The technical scheme of this comparative example is consistent with that of Example 1, except that the addition ratio of vitamin E, celery seed water extract and amaranth water extract is 1:1:0.8 (the weight concentration of vitamin E in the core layer solution is 1%). In addition, the raw materials used in this comparative example refer to those in Example 1.

[0069] The specific technical solutions are as follows:

[0070] Dressing preparation:

[0071] (1) CS and PVA in a weight ratio of 4:1 were dissolved in acetic acid solution to prepare a polymer solution with a concentration of 1% (w%). The solution was stirred on a constant temperature magnetic stirrer for 4 h until the polymer was completely dissolved and the final solution was a clear light orange-yellow color, which served as the shell liquid.

[0072] (2) Using deionized water as the solvent, vitamin E, amaranth water extract and PEG solution were blended to obtain an aqueous solution in which PEG accounted for 25% (w%), vitamin E accounted for 2% (w%) and amaranth water extract accounted for 1% (w%), which was used as the core layer liquid.

[0073] (3) The electrospinning parameters were set as follows: a fixed voltage of 15 kV, a dual-channel electrospinning propulsion pump was used to control the liquid flow rates of the shell layer and the core layer respectively, the shell layer syringe liquid feeding rate was 2 ml / h, and the core layer syringe liquid feeding rate was 0.5 ml / h; a coaxial needle was used as the nozzle, and a silver-coated "groove-gully" patterned glass plate was used as the receiving plate, and the distance between the needle and the receiving plate was 12 cm; the prepared nanofibers were placed in a vacuum drying oven and dried at 35 °C for 6 h to remove the residual solvent to obtain a dressing.

[0074] Comparative Example 3

[0075] The technical scheme of this comparative example is consistent with that of Example 1, except that the addition ratio of vitamin E, celery seed water extract and amaranth water extract is 1:1:0.5 (the weight concentration of vitamin E in the core layer solution is 1%). In addition, the raw materials used in this comparative example refer to those of Example 1.

[0076] The specific technical solutions are as follows:

[0077] Dressing preparation:

[0078] (1) CS and PVA in a weight ratio of 4:1 were dissolved in acetic acid solution to prepare a polymer solution with a concentration of 1% (w%). The solution was stirred on a constant temperature magnetic stirrer for 4 h until the polymer was completely dissolved and the final solution was a clear light orange-yellow color, which served as the shell liquid.

[0079] (2) Using deionized water as the solvent, vitamin E, amaranth water extract and PEG solution were blended to obtain an aqueous solution in which PEG accounted for 25% (w%), vitamin E accounted for 1% (w%) and amaranth water extract accounted for 3% (w%), which was used as the core layer liquid.

[0080] (3) The electrospinning parameters were set as follows: a fixed voltage of 15 kV, a dual-channel electrospinning propulsion pump was used to control the liquid flow rates of the shell layer and the core layer respectively, the shell layer syringe liquid feeding rate was 2 ml / h, and the core layer syringe liquid feeding rate was 0.5 ml / h; a coaxial needle was used as the nozzle, and a silver-coated "groove-gully" patterned glass plate was used as the receiving plate, and the distance between the needle and the receiving plate was 12 cm; the prepared nanofibers were placed in a vacuum drying oven at 35 °C for 6 h to remove the residual solvent to obtain a dressing.

[0081] Comparative Example 4

[0082] This comparative example 1 is the same as Example 1 except that the Amaranth water extract is replaced by the Purslane water extract. In addition, the raw materials used in this comparative example, except for the Purslane water extract, are the same as those in Example 1.

[0083] The preparation method of the purslane water extract used in this comparative example refers to the literature "Effects of purslane water extract on blood lipids in hyperlipidemic mice" (Pan Yuchen, Lv Youwei, Sun Mingjian, et al. Effects of purslane water extract on blood lipids in hyperlipidemic mice [J]. Journal of Beihua University (Natural Science Edition), 2023, 2403): 315-319.), and is slightly adjusted, specifically:

[0084] Take the commercially available dried aerial part of Purslane, grind it, add water at a solid-liquid weight volume ratio of 1g:10ml, extract it three times at 65°C using ultrasound, each time for 1.5 hours, combine the extracts, and perform rotary evaporation to obtain dry powder.

[0085] The specific technical solutions are as follows:

[0086] Dressing preparation:

[0087] (1) CS and PVA in a weight ratio of 4:1 were dissolved in acetic acid solution to prepare a polymer solution with a concentration of 1% (w%). The solution was stirred on a constant temperature magnetic stirrer for 4 h until the polymer was completely dissolved and the final solution was a clear light orange-yellow color, which served as the shell liquid.

[0088] (2) Using deionized water as the solvent, vitamin E, celery seed aqueous extract, purslane aqueous extract and PEG solution were blended to obtain an aqueous solution in which PEG accounted for 25% (w%), vitamin E accounted for 1% (w%), celery seed aqueous extract accounted for 1% (w%), and purslane aqueous extract accounted for 2% (w%) as the core layer liquid.

[0089] (3) The electrospinning parameters were set as follows: a fixed voltage of 15 kV, a dual-channel electrospinning propulsion pump was used to control the liquid flow rates of the shell layer and the core layer respectively, the shell layer syringe liquid feeding rate was 2 ml / h, and the core layer syringe liquid feeding rate was 0.5 ml / h; a coaxial needle was used as the nozzle, and a silver-coated "groove-gully" patterned glass plate was used as the receiving plate, and the distance between the needle and the receiving plate was 12 cm; the prepared nanofibers were placed in a vacuum drying oven and dried at 35 °C for 6 h to remove the residual solvent to obtain a dressing.

[0090] Comparative Example 5

[0091] In the preparation of the dressing in this example, ordinary aluminum foil is used as the receiving plate, and the rest is consistent with Example 1. In addition, the raw materials used in this comparative example refer to Example 1.

[0092] The specific technical solutions are as follows:

[0093] Dressing preparation:

[0094] (1) CS and PVA in a weight ratio of 4:1 were dissolved in acetic acid solution to prepare a polymer solution with a concentration of 1% (w%). The solution was stirred on a constant temperature magnetic stirrer for 4 h until the polymer was completely dissolved and the final solution was a clear light orange-yellow color, which served as the shell liquid.

[0095] (2) Using deionized water as the solvent, vitamin E, celery seed water extract, amaranth water extract and PEG solution were blended to obtain an aqueous solution in which PEG accounted for 25% (w%), vitamin E accounted for 1% (w%), celery seed water extract accounted for 1% (w%) and amaranth water extract accounted for 2% (w%) as the core layer liquid.

[0096] (3) The electrospinning parameters were set as follows: a fixed voltage of 15 kV, a dual-channel electrospinning propulsion pump was used to control the liquid flow rates of the shell layer and the core layer respectively, the shell layer syringe liquid feeding rate was 2 ml / h, and the core layer syringe liquid feeding rate was 0.5 ml / h; a coaxial needle was used as the nozzle, and ordinary aluminum foil was used as the receiving plate, and the distance between the needle and the receiving plate was 12 cm; the prepared nanofibers were placed in a vacuum drying oven at 35 °C for 6 h to remove the residual solvent to obtain a dressing.

[0097] Comparative Example 6

[0098] The technical solution of this comparative example is different from that of Example 1 in that no celery seed water extract is added to the core layer liquid, and the rest is consistent with Example 1. In addition, the raw materials used in this comparative example refer to those in Example 1.

[0099] The specific technical solutions are as follows:

[0100] Dressing preparation:

[0101] (1) CS and PVA in a weight ratio of 4:1 were dissolved in acetic acid solution to prepare a polymer solution with a concentration of 1% (w%). The solution was stirred on a constant temperature magnetic stirrer for 4 h until the polymer was completely dissolved and the final solution was a clear light orange-yellow color, which served as the shell liquid.

[0102] (2) Using deionized water as the solvent, vitamin E, amaranth water extract and PEG solution were blended to obtain an aqueous solution in which PEG accounted for 25% (w%), vitamin E accounted for 1% (w%) and amaranth water extract accounted for 2% (w%), which was used as the core layer liquid.

[0103] (3) The electrospinning parameters were set as follows: a fixed voltage of 15 kV, a dual-channel electrospinning propulsion pump was used to control the liquid flow rates of the shell layer and the core layer respectively, the shell layer syringe liquid feeding rate was 2 ml / h, and the core layer syringe liquid feeding rate was 0.5 ml / h; a coaxial needle was used as the nozzle, and a silver-coated "groove-gully" patterned glass plate was used as the receiving plate, and the distance between the needle and the receiving plate was 12 cm; the prepared nanofibers were placed in a vacuum drying oven and dried at 35 °C for 6 h to remove the residual solvent to obtain a dressing.

[0104] Comparative Example 7

[0105] This comparative example refers to the literature "Research on Drug-Loaded Coaxial Nanofiber Burn Dressing" (Liu Xiaoyan. Research on Drug-Loaded Coaxial Nanofiber Burn Dressing [D]. Academy of Military Medical Sciences of the Chinese People's Liberation Army, 2016.), and uses Centella asiatica glycosides to replace amaranth extract and celery seed water extract as the active ingredient in the core layer liquid, and the rest is consistent with Example 1; in addition, the raw materials used in this comparative example, except for Centella asiatica glycosides, the rest refer to Example 1; the Centella asiatica glycosides in this comparative example were purchased from Shanghai Modern Pharmaceutical Co., Ltd. (the total amount of Centella asiatica glycoside and madecassoside>60%).

[0106] The specific technical solutions are as follows:

[0107] Dressing preparation:

[0108] (1) CS and PVA in a weight ratio of 4:1 were dissolved in acetic acid solution to prepare a polymer solution with a concentration of 1% (w%). The solution was stirred on a constant temperature magnetic stirrer for 4 h until the polymer was completely dissolved and the final solution was a clear light orange-yellow color, which served as the shell liquid.

[0109] (2) Using deionized water as the solvent, vitamin E, total glycosides of Centella asiatica and PEG solution were mixed to obtain an aqueous solution in which PEG accounted for 25% (w%), vitamin E accounted for 1% (w%) and total glycosides of Centella asiatica accounted for 2% (w%), which was used as the core layer liquid.

[0110] (3) The electrospinning parameters were set as follows: a fixed voltage of 15 kV, a dual-channel electrospinning propulsion pump was used to control the liquid flow rates of the shell layer and the core layer respectively, the shell layer syringe liquid feeding rate was 2 ml / h, and the core layer syringe liquid feeding rate was 0.5 ml / h; a coaxial needle was used as the nozzle, and a silver-coated "groove-gully" patterned glass plate was used as the receiving plate, and the distance between the needle and the receiving plate was 12 cm; the prepared nanofibers were placed in a vacuum drying oven and dried at 35 °C for 6 h to remove the residual solvent to obtain a dressing.

[0111] Experimental Example 1

[0112] This experiment is an antibacterial test.

[0113] The tested bacteria included Gram-negative bacteria and Gram-positive bacteria. E. coli ATCC25922, Gram-positive bacteria S. aureus ATCC 29213, all prepared at a bacterial concentration of 1×10 8 CFU / mL bacterial suspension was used for antibacterial test.

[0114] Take the dressings obtained from each group, cut them into square dressing pieces of 1cm×1cm×1cm, place them in a glass test tube with a specification of 15mm×150mm, and pour the above test bacterial suspension into the glass test tube to half of the test tube capacity, incubate at 37℃ for 2 hours, take the bacterial suspension for plate counting to calculate the bacterial concentration. Then calculate the decrease in the bacterial concentration of the test bacterial suspension, and use the decrease as the antibacterial index. The experimental results are shown in Table 1.

[0115] Table 1

[0116]

[0117] As shown in Examples 1-3, Comparative Example 1, Comparative Example 6, Comparative Example 2 and Comparative Example 3 in Table 1, the addition of celery seed water extract has a synergistic effect on the antibacterial activity of amaranth water extract. At the same time, the addition ratio of celery seed extract and amaranth extract has an important influence on the synergistic effect.

[0118] It is worth noting that when the purslane water extract replaces the amaranth extract, as shown in Comparative Example 4, it has a better antibacterial effect than Comparative Example 1 and Comparative Example 6, but the improvement is limited and no significant difference is produced. This shows that the purslane water extract and the celery seed water extract do not produce a synergistic effect in antibacterial effect.

[0119] Experimental Example 2

[0120] This experiment is an antioxidant test.

[0121] DPPH and ABTS+ free radical scavenging tests were used to detect the antioxidant activity of each group of dressings and their free radical scavenging ability at different concentrations.

[0122] A 0.1 mM DPPH solution was prepared, and 30 mg of the dressing obtained in each group was put into 30 mL of DPPH solution. The absorbance change at 517 nm was recorded within 30 min using UV spectrophotometry.

[0123] A 0.1 mM ABTS+ solution was prepared, and 30 mg of the dressing obtained in each group was put into 30 mL of ABTS+ solution. The absorbance change at 749 nm was recorded within 30 min using UV spectrophotometry.

[0124] The free radical scavenging capacity of each group of dressings was calculated according to the following formula:

[0125]

[0126] Wherein, A0 is the absorbance of the solution before adding the dressing, and At is the absorbance of the solution at the corresponding time after adding the dressing.

[0127] The experimental results are shown in Table 2.

[0128] Table 2

[0129]

[0130] As shown in Table 2, the dressings of Examples 1-3 have excellent antioxidant properties, with a removal rate of more than 97% for DPPH and ABTS+ at a concentration of 0.1 mM, which is much better than the dressings obtained in the corresponding comparative examples. As shown in Comparative Examples 1 and 4, when the core solution does not add the amaranth water extract, the antioxidant properties of the obtained dressings decrease significantly; at the same time, it can be seen from Comparative Examples 2 and 3 that when the amaranth extract in the dressing is added less, the antioxidant properties of the obtained dressings decrease accordingly, which indicates that the presence of the amaranth water extract and the sufficient addition amount are important for the antioxidant properties of the dressing. For example, as shown in Comparative Example 6, the presence or absence of the celery seed water extract has no obvious effect on the antioxidant effect of the obtained dressing.

[0131] Experimental Example 3

[0132] This experiment is a moisture retention test.

[0133] The dry film of the dressing obtained in each group was weighed in advance, and then immersed in 20 mL of phosphate buffered saline (PBS) at 37°C. After swelling equilibrium, the hydrogel in swelling equilibrium was weighed, and then placed in an oven at 37°C and weighed after 24 hours. The weight difference before and after was calculated, and its water retention rate was calculated.

[0134] The experimental results are shown in Table 3.

[0135] Table 3

[0136]

[0137] As shown in Table 3, compared with the dressing using ordinary aluminum foil as the receiving plate, the dressings obtained in Examples 1-3 have better water retention.

[0138] Experimental Example 4

[0139] This experiment is a burn repair effect experiment.

[0140] 1. Establishment of Animal Model

[0141] Male SD rats (weight 190-200 g) were selected and fed adaptively for one week. They were allowed to drink water and eat freely. The back hair of the rats was shaved cleanly with an electric shaver before the experiment. Before the burn, the rats were anesthetized by intraperitoneal injection of 10% chloral hydrate at a dose of 4 ml / kg. The burn was performed using a desktop super-temperature controlled burn instrument. The burn head temperature of the burn instrument was 80°C, the diameter was 2 cm, the pressure was 500 g, and the contact time between the burn head and the skin was 8 s. The area of ​​the burn skin wound of the rat 24 h after the injury was taken as the initial burn area. On the 7th, 14th and 21st days after the burn, the wound photos were taken, and the burn wound area was calculated using Image Pro Plus 6.0 image analysis software. The wound healing rate was calculated using the following formula: wound healing rate = (initial burn area - wound area at each time point) / initial burn area × 100%.

[0142] According to the above experimental process, the rats were divided into 7 groups, with 5 rats in each group for testing.

[0143] 2. Experimental results

[0144] The experimental results are shown in Table 4.

[0145] Table 4

[0146]

[0147] As shown in Table 4, the wound healing rate of the dressing obtained in Example 1 reached 68% after 7 days of use, which is significantly higher than the use effect of the dressing obtained in the corresponding comparative example. Generally speaking, a wound healing rate of 95% is considered to be healed. It can be seen that the dressing of the present invention only needs to be used for 14 days to achieve the effect of healing, which has a better effect than the dressing containing the active substance Centella asiatica glycosides that promotes the healing of burn wounds. It is worth noting that comparative example 4 uses the water extract of purslane as the active ingredient of the core solution, and the resulting dressing is less effective in promoting wound healing, which is consistent with Zhang Zhenbang's [4] The reason for the different research results of others may be that the purslane extract is dose-dependent in promoting burn recovery and cannot promote wound healing at low doses.

[0148] This section refers to the prior art:

[0149] [4] Zhang Zhenbang, Yuan Xiaohua, Shen Yugang, et al. Treatment of 20 cases of second-degree burns with purslane extract [J]. Journal of Baotou Medical College, 1999(01):64. DOI:CNKI:SUN:BTYX.0.1999-01-041.

Claims

1. A method for preparing a patterned skin dressing with antioxidant, antibacterial and moisturizing properties, characterized in that: The preparation method comprises the following steps: (1) preparing a polymer solution with a mixture of chitosan and polyvinyl alcohol at a weight ratio of 3 to 5:1 as a shell layer solution; mixing the active ingredient into the polyethylene glycol aqueous solution as a core layer solution; (2) using a glass plate with a groove pattern as a receiving plate, a coaxial needle as a nozzle, and a dual-channel propulsion pump to control the flow rate of the shell layer liquid and the core layer liquid, and coaxially electrospinning the shell layer solution and the core layer solution obtained in step (1) to prepare a fiber membrane, thereby obtaining the skin dressing; Wherein, in step (1), the active ingredients include vitamin E, celery seed water extract and amaranth water extract in a weight ratio of 1:1:1-2.

2. The method for preparing a patterned skin dressing with antioxidant, antibacterial and moisturizing properties according to claim 1, characterized in that: The weight ratio of chitosan to polyvinyl alcohol is 4:

1.

3. The method for preparing a patterned skin dressing with antioxidant, antibacterial and moisturizing properties according to claim 2, characterized in that: The polymer solution is prepared by using a mixture of chitosan and polyvinyl alcohol. The chitosan and polyvinyl alcohol are dissolved in an acetic acid solution. The weight concentration of the obtained polymer solution is 1%.

4. The method for preparing a patterned skin dressing with antioxidant, antibacterial and moisturizing properties according to claim 1 or 3, characterized in that: In the core layer solution, the weight concentration of polyethylene glycol is 25%.

5. The method for preparing a patterned skin dressing with antioxidant, antibacterial and moisturizing properties according to claim 4, characterized in that: Among the active ingredients added to the core layer solution, the weight concentration of vitamin E in the core layer solution is 1%, the weight concentration of celery seed water extract in the core layer solution is 1%, and the weight concentration of amaranth extract in the core layer solution is 2%.

6. The method for preparing a patterned skin dressing with antioxidant, antibacterial and moisturizing properties according to claim 1 or 5, characterized in that: The groove-patterned glass plate is obtained by silver-plating on a non-conductive glass substrate by direct current magnetron sputtering. In the groove-patterned glass plate, the groove patterning is formed by a stripe pattern array, and the width of the stripe pattern is 200 μm.

7. The method for preparing a patterned skin dressing with antioxidant, antibacterial and moisturizing properties according to claim 6, characterized in that: During coaxial electrospinning, the voltage was 15 kV, the core solution feeding rate was 0.5 mL / h, the shell solution feeding rate was 2 mL / h, and the distance from the needle to the receiving plate was 12 cm.

8. The method for preparing a patterned skin dressing with antioxidant, antibacterial and moisturizing properties according to claim 7, characterized in that: In step (2), after preparing the fiber membrane, a treatment step of removing the residual solvent in the fiber membrane is also included; when performing the treatment step of removing the residual solvent in the fiber membrane, the obtained fiber membrane is placed in a vacuum drying oven at 35° C. and dried for 6 hours.

9. The method for preparing a patterned skin dressing with antioxidant, antibacterial and moisturizing properties according to claim 8, characterized in that: The amaranth extract is prepared by the following method: take the whole amaranth herb, wash it and cut it into pieces, add water at a solid-liquid weight ratio of 1:10, extract at 90°C for 2 hours, and filter to obtain the filtrate; then add water to the filter residue at a solid-liquid weight ratio of 1:10, extract at 90°C for another 2 hours, and filter to obtain the filtrate; combine the filtrates obtained from the two extractions, perform rotary evaporation, and obtain a dry powder; the celery seed water extract is prepared by the following method: take celery seeds, wash them, add water at a solid-liquid weight ratio of 1:15, extract at 90°C for 2 hours, and filter to obtain the filtrate; then add water to the filter residue at a solid-liquid weight ratio of 1:15, extract at 90°C for another 2 hours, and filter to obtain the filtrate; combine the filtrates obtained from the two extractions, perform rotary evaporation, and obtain a dry powder.

10. A patterned skin dressing with antioxidant, antibacterial and moisturizing properties, characterized in that: The skin dressing is prepared by the preparation method according to any one of claims 1 to 9.

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