Dendrobium officinale polysaccharide hydrogel mask as well as preparation method and application thereof

Abstract

The invention discloses a dendrobium officinale polysaccharide hydrogel mask and a preparation method and application thereof.The dendrobium officinale polysaccharide hydrogel mask is prepared from gelatin, sodium alginate, a cross-linking agent and a dendrobium officinale polysaccharide extracting solution, and the water content and the water retention property of the hydrogel mask obtained through the preparation method can be remarkably improved; the composition also has excellent oxidation resistance, skin repairing performance and skin moisture retention; in addition, due to simple components, the mask is green and non-toxic and has relatively high safety. Meanwhile, the preparation method is simple and convenient to operate and easy to prepare, and the bioavailability of the dendrobium officinale can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of cosmetic technology, and more specifically, to a Dendrobium officinale polysaccharide hydrogel mask, its preparation method, and its application. Background Technology

[0002] Dendrobium officinale ( Dendrobium officinale *Kinura et Migo* is a rare perennial herb, the second largest genus in the Orchidaceae family. It has a wide geographical distribution, including India, Australia, Japan, and the United States, and is widely distributed in China. *Dendrobium officinale* is a valuable traditional Chinese medicine, and modern medicine has demonstrated its benefits, including anti-cancer, anti-angiogenic, antioxidant, anti-diabetic, immune-enhancing, liver-protective, antifungal, antibacterial, and antiviral effects. Recent studies have confirmed that *Dendrobium officinale* contains polysaccharides with moisturizing, antioxidant, and anti-aging properties, attracting significant attention from dermatologists and cosmetic engineers. *Dendrobium officinale* polysaccharides exert their antioxidant effects through pathways such as reducing free radicals, enhancing the antioxidant system, inhibiting nuclear factor-kappa B, and downregulating inflammatory responses, laying the foundation for further research on the application of *Dendrobium officinale* polysaccharides in dermatology and promoting the active research of traditional Chinese medicine in dermatology.

[0003] Currently, hydrogel masks suffer from problems such as complicated preparation processes, difficult preparation methods, and components that are mainly chemically synthesized with numerous additives. As a result, only a small amount of effective ingredients are absorbed during use, and the various components in the preparation of hydrogel masks are not fully utilized to provide diversified effects.

[0004] Therefore, it is imperative to develop a Dendrobium officinale polysaccharide hydrogel product that can be applied in the cosmetics field and has excellent antioxidant, skin moisturizing, and repairing effects, while being safe and non-toxic.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a Dendrobium officinale polysaccharide hydrogel mask, its preparation method and application. The preparation method provided by this invention can significantly improve the water content and water retention of the hydrogel mask, and it also has excellent antioxidant properties, skin repair properties and skin moisturizing properties.

[0007] This invention is implemented as follows: In a first aspect, the present invention provides a Dendrobium officinale polysaccharide hydrogel, the components of which are gelatin, sodium alginate, crosslinking agent and Dendrobium officinale polysaccharide extract.

[0008] Secondly, the present invention provides a method for preparing the above-mentioned Dendrobium officinale polysaccharide hydrogel, comprising: The gelatin is dissolved in the dendrobium officinale polysaccharide extract solution, and is stirred uniformly under heating; then, the sodium alginate is added to the mixed solution, and is stirred uniformly under heating to obtain a dendrobium officinale polysaccharide sol; The dendrobium officinale polysaccharide sol is refrigerated; then, the crosslinking agent is added dropwise to the surface of the cooled sol, and the crosslinking reaction is completed to obtain the dendrobium officinale polysaccharide hydrogel after cleaning.

[0009] In a third aspect, the present application provides application of the dendrobium officinale polysaccharide hydrogel or the dendrobium officinale polysaccharide hydrogel obtained by the preparation method in the preparation of a mask product with antioxidant, moisturizing and repairing effects.

[0010] The present application has the following beneficial effects: (1) The present application combines the dendrobium officinale polysaccharide extract solution, the gel matrix and the crosslinking agent to obtain a dendrobium officinale polysaccharide hydrogel, which has the antioxidant and repairing effects of the dendrobium officinale polysaccharide, and can improve the water content and water retention, thereby achieving excellent skin moisturizing property, and the water content of the mask is still higher than 70% even after 1 hour of use, so that the effects of the dendrobium officinale polysaccharide can be effectively exerted under the condition of ensuring the water content of the mask.

[0011] (2) The dendrobium officinale polysaccharide hydrogel of the present application can absorb the dendrobium officinale polysaccharide to a great extent, so that the dendrobium officinale polysaccharide can be better utilized by the skin, and has high bioavailability.

[0012] (3) The dendrobium officinale polysaccharide hydrogel of the present application has simple components, and the components are composed of natural substances without adding any chemicals, so it has the characteristics of safety and non-toxicity.

[0013] (4) The dendrobium officinale polysaccharide hydrogel of the present application can be prepared into related products such as masks, and has simple preparation process and is suitable for large-scale production. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and should not be regarded as a limitation on the scope, and other related drawings can also be obtained by those skilled in the art without creative labor on the premise of not paying.

[0015] Figure 1 The water retention detection result of the 3% dendrobium officinale polysaccharide hydrogel; Figure 2 The moisturizing property detection result of the 3% dendrobium officinale polysaccharide hydrogel on the skin; Figure 3 The hemolysis experiment detection result of the 3% dendrobium officinale polysaccharide hydrogel; Figure 4 Swelling test results of 3% Dendrobium candidum polysaccharide hydrogel; Figure 5 Comparison results of the size of the original 3% Dendrobium candidum polysaccharide hydrogel and the 3% Dendrobium candidum polysaccharide hydrogel after swelling; Figure 6 Comparison of the mechanical properties of 1% Dendrobium candidum polysaccharide hydrogel and 3% Dendrobium candidum polysaccharide hydrogel; wherein: 1% is Example 2; 3% is Example 1; Figure 7 Pictures of Dendrobium candidum polysaccharide hydrogel prepared by gelatin and hyaluronic acid gel matrix and Dendrobium candidum polysaccharide hydrogel prepared by sodium alginate and hyaluronic acid gel matrix; wherein: gelatin and hyaluronic acid gel matrix is Comparative Example 1; sodium alginate and hyaluronic acid gel matrix is Comparative Example 2; Figure 8 Pictures of 3% Dendrobium candidum polysaccharide hydrogel prepared without the step of refrigeration; Figure 9 Pictures of 3% Dendrobium candidum polysaccharide hydrogel prepared by using polyvinyl alcohol and sodium alginate as the matrix; Figure 10 Pictures of 3% Dendrobium candidum polysaccharide hydrogel prepared by using pullulan and sodium alginate as the matrix; Figure 11 Pictures of 3% Dendrobium candidum polysaccharide hydrogel prepared by using polyacrylic acid sodium and sodium alginate as the matrix; Figure 12 DPPH free radical scavenging test results of 3% Dendrobium candidum polysaccharide hydrogel prepared by using gelatin and sodium alginate as the matrix and 3% Dendrobium candidum polysaccharide hydrogel prepared by using pullulan and sodium alginate as the matrix; Figure 13 Pictures of 3% Dendrobium candidum polysaccharide hydrogel eye mask; Figure 14 Pictures of 3% Dendrobium candidum polysaccharide hydrogel facial mask. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below. If the specific conditions are not indicated in the embodiments, the conventional conditions or the conditions suggested by the manufacturer are adopted. If the reagents or instruments used are not indicated by the manufacturer, they are all conventional products that can be purchased in the market.

[0017] The present application provides a Dendrobium candidum polysaccharide hydrogel and a preparation method thereof, which comprises the following steps: (1) Dissolve gelatin in the Dendrobium candidum polysaccharide extract solution and stir uniformly under heating conditions.

[0018] In the present application, the Dendrobium officinale polysaccharide extract is selected as the main active ingredient. On the one hand, Dendrobium officinale is the second largest genus of Orchidaceae, and the Dendrobium officinale polysaccharide is the main active substance in Dendrobium officinale, which has multiple effects such as antioxidant, anti-inflammatory, anti-aging and repair, and is derived from natural herbal plants, and has high safety. On the other hand, not all natural polysaccharide substances or other active substances can be well integrated with other components of the hydrogel. It is found in the present application that the Dendrobium officinale polysaccharide can be fully integrated with gel matrices such as gelatin and sodium alginate, and the hydrogel prepared therefrom can enable the Dendrobium officinale polysaccharide to be better utilized by the skin.

[0019] In some embodiments, the Dendrobium officinale polysaccharide extract is obtained by extracting Dendrobium officinale raw materials with water, wherein the solid-liquid ratio is 1-3:100 (g / g). When the raw material is fresh Dendrobium officinale strips, the solid-liquid ratio is preferably 3:100 (g / g); when the raw material is dry Dendrobium officinale, the solid-liquid ratio is preferably 1:100 (g / g). The content of Dendrobium officinale polysaccharide in the Dendrobium officinale polysaccharide extract obtained by this method is 6-11 mg / mL.

[0020] For the preparation method of the Dendrobium officinale polysaccharide extract, other conventional extraction methods in the art can also be used.

[0021] In some embodiments, the temperature of the heating condition is 50-60°C. Specifically, the heating temperature can be 50°C, 51°C, 52°C, 53°C, 55°C, 58°C or 60°C, or any other value between 50°C and 60°C.

[0022] (2) Adding sodium alginate to the mixed solution obtained in step (1) and stirring uniformly under heating conditions to obtain a Dendrobium officinale polysaccharide sol.

[0023] In some embodiments, the temperature of the heating condition is 50-60°C. Specifically, the heating temperature can be 50°C, 51°C, 52°C, 53°C, 55°C, 58°C or 60°C, or any other value between 50°C and 60°C.

[0024] In some embodiments, the volume mass ratio of the Dendrobium officinale polysaccharide extract, gelatin and sodium alginate is 1:1:1-50:10:1 (mL / g / g). A ratio that is too low can result in poor mechanical properties of the Dendrobium officinale polysaccharide hydrogel mask prepared therefrom, or even failure to form a gel; a ratio that is too high can result in a Dendrobium officinale polysaccharide hydrogel mask with a tough texture and poor skin adhesion.

[0025] In the present application, the gelatin is first mixed with the dendrobium officinale polysaccharide extract solution, and then mixed with sodium alginate. The purpose is to fully dissolve the two components. After the sodium alginate is dissolved, it has a large viscosity. If the sodium alginate is first mixed with the dendrobium officinale polysaccharide extract solution, and then mixed with the gelatin, the gelatin may not be fully dissolved and the dissolution time may be too long.

[0026] (3) Put the sol obtained in (2) into a refrigerator for refrigeration.

[0027] In some embodiments, the refrigeration temperature is 0-10℃, and the refrigeration time is 5-15 min. The refrigeration function is to solidify the sol, which is convenient for subsequent crosslinking work.

[0028] (4) Add calcium chloride solution to the surface of the sol after cooling in (3) to crosslink.

[0029] In the present application, when the calcium chloride solution is added to the surface of the sol, the amount of calcium chloride added is determined by the fact that the calcium chloride solution completely covers the surface of the sol. It is found in the experiment that only adding the calcium chloride solution to the surface of the sol will prolong the time and cause the problem of incomplete gelation at the bottom. Therefore, in the present application, the calcium chloride solution that can completely cover the surface of the sol is added to the surface of the sol during crosslinking, so as to shorten the crosslinking time and eliminate the incomplete gelation phenomenon.

[0030] In some embodiments, the mass fraction of the calcium chloride solution is 2%. If the mass fraction of the calcium chloride solution is too low, the interaction between the calcium chloride molecules is small, which will form a hydrogel with a large pore size, thereby resulting in poor mechanical properties of the hydrogel or even no gelation; if the mass fraction of the calcium chloride solution is too high, the interaction between the calcium chloride molecules is large, which will form a hydrogel with a small pore size, thereby resulting in a tough hydrogel and poor adhesion to the skin.

[0031] In some embodiments, the crosslinking time is 5-20 min. Specifically, the crosslinking time can be 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min or 20 min, or any other value between 5 min and 20 min.

[0032] (5) After the crosslinking in (4) is completed, the dendrobium officinale polysaccharide hydrogel is obtained by washing with ultrapure water.

[0033] Preferably, the preparation method can be: 0.1 g gelatin is added to 2.5 mL 3% Dendrobium candidum polysaccharide extract solution, and stirred and dissolved at 50-60°C. After the gelatin is completely dissolved, 0.05 g sodium alginate is added, and stirred and dissolved at 50-60°C. After the sodium alginate is completely dissolved, it is placed in a refrigerator for cold storage for 5-15 min. After the cold storage is completed, 2% calcium chloride solution is completely covered on the surface of the sol, and crosslinking is performed for 5-20 min. After that, the hydrogel is washed with ultrapure water for 3 times to obtain the Dendrobium candidum polysaccharide hydrogel.

[0034] The Dendrobium candidum polysaccharide hydrogel obtained by the above preparation method has simple composition, and all the components are natural ingredients without chemical substances. The Dendrobium candidum polysaccharide hydrogel has excellent antioxidant property, skin moisturizing property and skin repairing effect while ensuring safety. Therefore, the Dendrobium candidum polysaccharide hydrogel can be applied to the preparation of film-type cosmetics, including face masks, eye masks, neck masks, hand masks and lip masks.

[0035] For example, the face mask is prepared by adding sodium alginate to the mixed solution, pouring the prepared sol into a face mask mold, and then placing it in a refrigerator for cold storage. After the cold storage, crosslinking reaction is performed, and then the Dendrobium candidum polysaccharide hydrogel face mask is obtained by washing with ultrapure water.

[0036] The features and properties of the present application are further described in detail below in combination with examples.

[0037] The purchase manufacturers and item numbers of the reagents used in the following examples are as follows:

[0038] The preparation method of the Dendrobium candidum polysaccharide extract solution used in the following examples is as follows: (1) The fresh Dendrobium candidum strips are washed, crushed, and added with deionized water at a mass ratio of 3:100 for normal temperature soaking for 30 min; (2) Then, micro-boiling heating reflux extraction (90-95°C) is performed. After the temperature meets the condition, the extraction is performed for 4 h; (3) After the extraction is completed, the residue is filtered with 300 mesh filter cloth while hot (above 60°C), and coarse filtration is performed (plate frame + 80 μm filter paper). After the coarse filtration is completed, 4°C low-temperature standing is performed for 24-36 h. After the standing is completed, fine filtration is performed (plate frame + 0.22 μm filter paper + filter aid); (4) The obtained fine filtrate is sterilized at 90°C for 30 min, cooled to 50°C, and a preservative system (0.5% p-hydroxyacetophenone + 2% 1,2-hexanediol + 5% glycerol) is compounded. After complete dissolution under stirring and heat preservation, the Dendrobium candidum polysaccharide extract solution (hereinafter referred to as 3% Dendrobium candidum polysaccharide extract solution) is obtained. The Dendrobium candidum polysaccharide contained therein is 6-7 mg / mL.

[0039] Using the above extraction method, taking dry Dendrobium officinale Kimura et Migo as raw material, extracting according to the ratio of 1:100, the obtained extract is hereinafter referred to as 1% Dendrobium officinale Kimura et Migo polysaccharide extract, wherein the Dendrobium officinale Kimura et Migo polysaccharide contained therein is 10-11 mg / mL.

[0040] Example 1 The present example is a preparation method of Dendrobium officinale Kimura et Migo polysaccharide hydrogel using gelatin and sodium alginate as the matrix, comprising the following steps: (1) 0.1 g of gelatin is added to 2.5 mL of 3% Dendrobium officinale Kimura et Migo polysaccharide extract, and dissolved by stirring at a temperature of 50°C-60°C; (2) After the gelatin is completely dissolved, 0.05 g of sodium alginate is added, and dissolved by stirring at a temperature of 50°C-60°C; (3) After the sodium alginate is completely dissolved, the sol is poured into a 24-well plate at a rate of 0.5 mL / well, and placed in a refrigerator for cold storage for 5-6 min; (4) After the cold storage is completed, 2% calcium chloride solution is used to completely cover the surface of the sol, and cross-linked for 10-15 min, and then the hydrogel is washed with ultrapure water for three times to obtain the Dendrobium officinale Kimura et Migo polysaccharide hydrogel.

[0041] Example 2 The difference from Example 1 is only that the 3% Dendrobium officinale Kimura et Migo polysaccharide extract is replaced by 1% Dendrobium officinale Kimura et Migo polysaccharide extract, and the other steps are the same as those of Example 1.

[0042] Comparative Example 1 The difference from Example 1 is only that the sodium alginate is replaced by hyaluronic acid, and the other steps are the same as those of Example 1.

[0043] Comparative Example 2 The difference from Example 1 is only that the gelatin is replaced by hyaluronic acid, and the other steps are the same as those of Example 1.

[0044] Comparative Example 3 The difference from Example 1 is only that the cold storage step is not performed, and the other steps are the same as those of Example 1.

[0045] Comparative Example 4 The present experiment is a preparation method of Dendrobium officinale Kimura et Migo polysaccharide hydrogel using polyvinyl alcohol and sodium alginate as the matrix, comprising the following steps: (1) 0.4 g of polyvinyl alcohol is added to 3 mL of 3% Dendrobium officinale Kimura et Migo polysaccharide extract, and dissolved by stirring at a temperature of 90°C; (2) After the polyvinyl alcohol is completely dissolved, 0.03 g of sodium alginate is added, and dissolved by stirring at a temperature of 90°C; (3) After the sodium alginate is completely dissolved, pour the sol into a 24-well plate at a rate of 0.5 mL / well and freeze it in a refrigerator for 3 h. (4) After freezing, thaw at room temperature for 3 hours; (5) Freeze and thaw again. After the second thawing, completely cover the surface of the sol with 2% calcium chloride solution. After crosslinking for 10-15 minutes, wash the hydrogel three times with ultrapure water.

[0046] Comparative Example 5 The only difference from Example 1 is that gelatin is replaced with pullulanose; the other steps are the same as in Example 1.

[0047] Comparative Example 6 The only difference from Example 1 is that 0.1 g of gelatin is replaced with 0.05 g of sodium polyacrylate, and 2.5 mL of 3% Dendrobium officinale polysaccharide extract is replaced with 6 mL. The other steps are the same as in Example 1.

[0048] Experimental Example 1. The determination of the water retention capacity of the 3% Dendrobium officinale polysaccharide hydrogel obtained in Example 1 includes the following steps: (1) Determination of water content of 3% Dendrobium officinale polysaccharide hydrogel obtained in Example 1: Three pieces of the prepared 3% Dendrobium officinale polysaccharide hydrogel were weighed and frozen overnight at -80°C. After the hydrogel was completely frozen, it was freeze-dried in a freeze dryer for 48 hours. The weights were then calculated, and the average water content of the 3% Dendrobium officinale polysaccharide hydrogel was taken. The water content of the hydrogel was calculated using the following formula:

[0049] The water content of the 3% Dendrobium officinale polysaccharide hydrogel was 94.34%.

[0050] (2) Determination of the water retention of the 3% Dendrobium officinale polysaccharide hydrogel obtained in Example 1: Three hydrogel samples were weighed and then exposed to air at room temperature. They were weighed every 10 minutes for 2 hours. The water retention capacity of the 3% Dendrobium officinale polysaccharide hydrogel was calculated using the following formula.

[0051] like Figure 1 As shown, the hydrogel lost 44.14% of its water after being exposed to air at room temperature for 2 hours, and still contained 50.20% water, indicating that the hydrogel has good water retention.

[0052] 2. Skin moisturizing effect determination of the 3% Dendrobium officinale polysaccharide hydrogel obtained in Example 1. The method for measuring the water content of the skin after the 3% Dendrobium candidum polysaccharide hydrogel obtained in Example 1 is applied to the skin is as follows: Three volunteers are selected, the forearms of the three volunteers are washed, the water content of the skin of the forearms of the three volunteers is detected, four pieces of 3% Dendrobium candidum polysaccharide hydrogel are applied to the forearms of the three volunteers respectively, one piece of hydrogel is removed after 15 min to measure the water content of the skin covered by the hydrogel, one piece of hydrogel is removed after 30 min to measure the water content of the skin covered by the hydrogel, one piece of hydrogel is removed after 45 min to measure the water content of the skin covered by the hydrogel, one piece of hydrogel is removed after 60 min to measure the water content of the skin covered by the hydrogel, and the average value of the data of the three volunteers is plotted.

[0053] From the results of Figure 2 It can be seen from the experiment that the water content of the skin is obviously increased when the hydrogel is applied to the skin for 15 min, indicating that the hydrogel has excellent skin moisturizing property.

[0054] 3. Hemolysis experiment of the 3% Dendrobium candidum polysaccharide hydrogel obtained in Example 1 The method for the hemolysis experiment is as follows: First, 1 mL of rabbit blood is centrifuged, the supernatant and the middle layer are discarded, 20 μL of the precipitate is taken and mixed with 980 μL of normal saline to obtain a 2% red blood cell solution, 1 mL of the 2% red blood cell solution is mixed with 20 μL of normal saline as a negative control group, 1 mL of the 2% red blood cell solution is mixed with 20 μL of Triton x 100 as a positive control group, 1.02 mL of the 2% red blood cell solution is added to a centrifuge tube containing 1 g of hydrogel as an experimental group, the experimental group, the negative control group and the positive control group are prepared in three groups respectively, mixed and placed for 3 h, and the supernatant is taken after centrifugation to measure the absorption at 541 nm.

[0055] Figure 3 The experimental results of the hydrogel are as follows: the hemolysis rate of the hydrogel is 0.6439%, which is much smaller than 5%, and the hydrogel has good blood compatibility.

[0056] 4. Swelling property of the 3% Dendrobium candidum polysaccharide hydrogel obtained in Example 1 (1) Freeze-drying of the 3% Dendrobium candidum polysaccharide hydrogel obtained in Example 1: Three pieces of the prepared 3% Dendrobium candidum polysaccharide hydrogel are frozen in a-80 °C refrigerator for one night, the hydrogel is completely frozen, and then is placed in a freeze dryer for freeze-drying, and is taken out after freeze-drying for 48 h and weighed.

[0057] (2) Measurement of the swelling property of the 3% Dendrobium candidum polysaccharide hydrogel obtained in Example 1: The freeze-dried 3% Dendrobium candidum polysaccharide hydrogel is placed in ultrapure water, and is weighed every 1 h, the experiment is performed for 8 h, and the average value of the data of three pieces of hydrogel is plotted.

[0058] Figure 4 The experimental results show that the swelling rate reaches its maximum value after soaking in ultrapure water for 7 hours.

[0059] 5. Comparison of morphology and size between 3% Dendrobium officinale polysaccharide hydrogel after swelling and the original 3% Dendrobium officinale polysaccharide hydrogel. (1) 3% Dendrobium officinale polysaccharide hydrogel freeze-dried: Three pieces of the prepared 3% Dendrobium officinale polysaccharide hydrogel were frozen overnight in a -80 °C freezer. After the hydrogel was completely frozen, it was placed in a freeze dryer for freeze drying and removed after 48 hours.

[0060] (2) Determination of swelling properties of 3% Dendrobium officinale polysaccharide hydrogel: The lyophilized 3% Dendrobium officinale polysaccharide hydrogel was placed in ultrapure water for 8 hours and then compared with the original hydrogel. Figure 5 The left side shows the original hydrogel, and the right side shows the hydrogel after freeze-drying and soaking. The experimental results show that after the freeze-dried hydrogel was soaked in ultrapure water for 8 hours, there was little change compared with the original hydrogel.

[0061] Comparison of mechanical properties of 6.1% Dendrobium officinale polysaccharide hydrogel and 3% Dendrobium officinale polysaccharide hydrogel Figure 6 The experimental results showed that the morphological integrity of 1% Dendrobium officinale polysaccharide hydrogel was not as good as that of 3% Dendrobium officinale polysaccharide hydrogel, indicating that the mechanical properties of 3% Dendrobium officinale polysaccharide hydrogel were better than those of 1% Dendrobium officinale polysaccharide hydrogel. This also reflects that excessively high Dendrobium officinale polysaccharide content can affect the morphological integrity of hydrogel and reduce mechanical properties.

[0062] 7.3% Dendrobium officinale polysaccharide hydrogel alters the gel matrix: The hydrogels prepared in Comparative Examples 1 and 2 were compared with the hydrogel prepared in Example 1. Figure 7 The left side is a schematic diagram of Comparative Example 1. Figure 7 The diagram on the right is a schematic of Comparative Example 2. The experimental results show that changing the gel matrix of gelatin and sodium alginate leads to non-gelation or poor gel mechanical properties.

[0063] 8. Comparative Example 3: Gel preparation without refrigeration. The hydrogel prepared in Comparative Example 3 was compared with the hydrogel prepared in Example 1. Figure 8 The experimental results show that without the refrigeration step, the crosslinking agent will mix with the sol and cannot form a gel.

[0064] 9. In Comparative Example 4, gels were prepared using polyvinyl alcohol and sodium alginate as the matrix. The hydrogel prepared in Comparative Example 4 was compared with the hydrogel prepared in Example 1. Figure 9The experimental results show that the gel prepared in Comparative Example 4 has poor mechanical properties and is very easy to break, and cannot be used for mask preparation.

[0065] 10. Gel prepared in Comparative Example 5 using pullulan and sodium alginate as the matrix The hydrogel prepared in Comparative Example 5 was compared with the hydrogel prepared in Example 1, Figure 10 The experimental results show that the gel prepared in Comparative Example 5 has an abnormal shape and cannot guarantee the uniformity of the product shape.

[0066] 11. Gel prepared in Comparative Example 6 using sodium polyacrylate and sodium alginate as the matrix The hydrogel prepared in Comparative Example 6 was compared with the hydrogel prepared in Example 1, Figure 11 The experimental results show that the gel prepared in Comparative Example 6 shrinks and cannot be shaped.

[0067] 12. DPPH radical scavenging of 3% Dendrobium candidum polysaccharide hydrogel prepared using gelatin and sodium alginate as the matrix and 3% Dendrobium candidum polysaccharide hydrogel prepared using pullulan and sodium alginate as the matrix in Comparative Example 7 was detected, as follows: (1) Preparation of DPPH ethanol solution: 20 mg of DPPH was weighed, dissolved in anhydrous ethanol, and diluted to a 250 mL volumetric flask. The DPPH concentration was configured to be 2 x 10 -4 mol / L, and stored at 0-4°C in the dark; (2) 3% Dendrobium candidum polysaccharide sol prepared using gelatin and sodium alginate as the matrix and 3% Dendrobium candidum polysaccharide sol prepared using pullulan and sodium alginate as the matrix were prepared according to Example 1 and Example 4; (3) 1 mL of the hydrogel sol of the two matrices was taken into a 2 mL centrifuge tube, and placed in a refrigerator for 5-6 min. After the cold storage was completed, 2% calcium chloride solution was completely covered on the surface of the sol, and crosslinked for 10-15 min. The hydrogel was washed with ultrapure water three times; (4) 1 mL of DPPH solution was taken and added to the centrifuge tube containing the two kinds of hydrogel, so that the DPPH solution was mixed with the hydrogel (tube A); (5) 1 mL of ultrapure water was taken and added to the centrifuge tube containing the two kinds of hydrogel, so that the ultrapure water was mixed with the hydrogel (tube B); (6) 200 μL of ultrapure water was mixed with 200 μL of DPPH solution (tube C); (7) Under light-proof conditions, after 30 min of reaction, centrifugation was performed at a speed of 7100 rpm for 5 min, and 200 μL of supernatant was taken, and the absorbance value was detected at 517 nm on an enzyme marker; (8) Clearance rate calculation formula: clearance rate (%) = [(B+C)-A] / B*100% The experimental results are shown in Figure 12 The antioxidant activity of the 3% D. candidum polysaccharide hydrogel prepared by using gelatin and sodium alginate as the matrix can reach 26.86%, while the 3% D. candidum polysaccharide hydrogel prepared by using pru blue sugar and sodium alginate as the matrix does not show antioxidant activity, and the error causes a negative value.

[0068] 13. Preparation of 3% D. candidum polysaccharide eye mask: 0.1 g of gelatin was added to 2.5 mL of 3% D. candidum polysaccharide extract solution, and stirred and dissolved at a temperature of 50-60 °C. After the gelatin was completely dissolved, 0.05 g of sodium alginate was added, and stirred and dissolved at a temperature of 50-60 °C. After the sodium alginate was completely dissolved, 2 mL was poured into an eye mask mold, and placed in a refrigerator for cold storage for 5-6 min. After the cold storage was completed, a 2% calcium chloride solution was completely covered on the surface of the sol, and cross-linked for 10-15 min. The hydrogel eye mask was obtained by washing the hydrogel mask with ultrapure water three times, and the physical map is shown in Figure 13 .

[0069] 14. Preparation of 3% D. candidum polysaccharide hydrogel mask: 0.1 g of gelatin was added to 2.5 mL of 3% D. candidum polysaccharide extract solution, and stirred and dissolved at a temperature of 50-60 °C. After the gelatin was completely dissolved, 0.05 g of sodium alginate was added, and stirred and dissolved at a temperature of 50-60 °C. After the sodium alginate was completely dissolved, 2 mL was poured into an eye mask mold, and placed in a refrigerator for cold storage for 5-6 min. After the cold storage was completed, a 2% calcium chloride solution was completely covered on the surface of the sol, and cross-linked for 10-15 min. The hydrogel eye mask was obtained by washing the hydrogel mask with ultrapure water three times, and the physical map is shown in Figure 14 .

[0070] The above results show that the D. candidum polysaccharide hydrogel mask prepared by the specific ratio of the present application has the advantages of simple preparation method, safety and non-toxicity, good water retention, outstanding antioxidant activity, good skin moisturizing property, etc., and can be applied to the field of cosmetics, and greatly improves the bioavailability of D. candidum polysaccharide.

[0071] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A Dendrobium candidum polysaccharide hydrogel, characterized in that, The components are gelatin, sodium alginate, crosslinking agent and Dendrobium officinale Kimura et Migo polysaccharide extract.

2. The Dendrobium polysaccharide hydrogel according to claim 1, characterized in that, The volume-mass ratio of the Dendrobium officinale Kimura et Migo polysaccharide extract, gelatin and sodium alginate is 1:1:1-50:10:1 (mL / g / g).

3. The Dendrobium candidum polysaccharide hydrogel of claim 2, characterized in that, The content of Dendrobium officinale Kimura et Migo polysaccharide in the Dendrobium officinale Kimura et Migo polysaccharide extract is 6-11 mg / mL.

4. The Dendrobium candidum polysaccharide hydrogel of claim 1, characterized in that, The crosslinking agent comprises calcium chloride solution.

5. The Dendrobium candidum polysaccharide hydrogel of claim 4, characterized in that, The mass concentration of the calcium chloride solution is 0.5%-5%.

6. The preparation method of Dendrobium candidum polysaccharide hydrogel according to any one of claims 1-5, characterized in that, The method comprises the following steps: The gelatin is dissolved in the Dendrobium officinale Kimura et Migo polysaccharide extract, and stirred uniformly under heating; Then, the sodium alginate is added to the mixed solution, and stirred uniformly under heating to obtain the Dendrobium officinale Kimura et Migo polysaccharide sol; The Dendrobium officinale Kimura et Migo polysaccharide sol is refrigerated, and then the crosslinking agent is added dropwise to the surface of the cooled sol, and the Dendrobium officinale Kimura et Migo polysaccharide hydrogel is obtained after the crosslinking reaction and cleaning.

7. The preparation method according to claim 6, characterized in that, The heating temperature for stirring when the gelatin and the Dendrobium officinale Kimura et Migo polysaccharide extract are mixed is 50-60°C; the heating temperature for stirring when the mixed solution and the sodium alginate are mixed is 50-60°C.

8. The preparation method according to claim 6, characterized in that, The refrigeration temperature is 0-10°C, and the refrigeration time is 5-15 min.

9. The preparation method according to claim 6, characterized in that, When the crosslinking agent is added dropwise to the surface of the cooled sol, the dropwise amount is: until the crosslinking agent completely covers the surface of the sol; The crosslinking reaction time is 5-20 min.

10. The use of the Dendrobium officinale Kimura et Migo polysaccharide hydrogel of any one of claims 1-5 or the Dendrobium officinale Kimura et Migo polysaccharide hydrogel obtained by the preparation method of any one of claims 6-9 in preparing a mask product with antioxidant, moisturizing and repairing effects.

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