Repair gel containing mesenchymal stem cell exosome and preparation method thereof

Abstract

The invention relates to the technical field of repair gel, in particular to repair gel containing mesenchymal stem cell exosomes and a preparation method of the repair gel, and the preparation method comprises the following steps: uniformly blending exosome freeze-dried powder, a modified shell agent and a silicon dioxide coating solution according to a weight ratio of (7-9): (4-6): 4 to obtain the repair gel. The preparation method of the repair gel containing the mesenchymal stem cell exosome comprises the following steps: uniformly blending exosome freeze-dried powder, a modified shell agent and a silicon dioxide coating solution according to a weight ratio of (7-9): (4-6): 4 to obtain the repair gel.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of repair gels, in particular to a mesenchymal stem cell exosome-containing repair gel and a preparation method thereof. BACKGROUND

[0002] In the field of skin damage repair and skin care, traditional repair products have many limitations. For example, although common antibiotic ointments have certain inhibitory effect on wound infection, long-term use is easy to produce drug resistance, and the effect on skin cell regeneration and repair is limited; and exosomes are a kind of vesicular structure secreted by mammalian cells through the "endocytosis-exocytosis" process. The existing repair gel has poor acne repair property, and the moisturizing property of the product is poor, so it is difficult for the product to realize the coordinated improvement of acne repair property and moisturizing property, and the long-acting moisturizing property of the product is poor, which limits the use efficiency of the product. SUMMARY

[0003] In view of the defects of the prior art, the purpose of the present application is to provide a mesenchymal stem cell exosome-containing repair gel and a preparation method thereof, so as to solve the problems raised in the background art.

[0004] The technical problem solved by the present application adopts the following technical scheme: The present application provides a preparation method of a mesenchymal stem cell exosome-containing repair gel, comprising the following steps: blending uniformly exosome freeze-dried powder, modified shell agent and silicon dioxide coating liquid according to a weight ratio of (7-9):(4-6):4 to obtain the repair gel.

[0005] Preferably, the exosome freeze-dried powder is made of the prior art of CN113797151B One kind of mesenchymal stem cell exosome-containing repair gel and a preparation method thereof Example 1.

[0006] Preferably, the preparation method of the modified shell agent is: S01: heat-treating the shell powder at 130-140℃ for 1h, then cooling to 55℃ at a rate of 2-5℃ / min, and keeping the temperature; S02: preparation of the modification liquid: S02a: adding 2-4 parts of carboxymethyl cellulose and 1-3 parts of brown algae extract to 5-8 parts of 5% mass fraction sodium citrate solution and stirring uniformly to obtain a brown algae composite liquid; S02b: mixing 2-5 parts of collagen and 4-7 parts of fermentation composite liquid and ultrasonic treatment, and after ultrasonic treatment, obtaining a collagen liquid; blending and stirring uniformly the brown algae composite liquid and the collagen liquid according to a weight ratio of 5:3 to obtain a modification liquid; S03: stirring the heat-treated shell powder in the modification liquid at 4-7 times the total amount of the heat-treated shell powder, and after stirring, filtering and drying to obtain a modified shell agent.

[0007] Preferably, the ultrasonic power of the mixed ultrasonic treatment is 350-400 W, and the ultrasonic treatment lasts for 1 h; the stirring speed of the stirring treatment is 450-500 r / min, and the stirring treatment lasts for 2 h.

[0008] Preferably, the specific preparation method of the brown algae extract is as follows: The brown algae is crushed to 100 meshes, and then is extracted in a sufficient amount of 95% ethanol solution, the extraction temperature is 65-70 DEG C, the extraction lasts for 5 h, after the extraction is completed, filtration is performed, an extract is obtained, and then concentration and drying are performed to obtain the brown algae extract.

[0009] Preferably, the preparation method of the fermentation complex liquid is as follows: The shea nut oil, centella asiatica and saposhnikovia divaricata root are uniformly blended according to the weight ratio (2-4):5:(1-3) to obtain a uniformly blended material, 10-15% of bacillus subtilis is added to the uniformly blended material, and then fermentation treatment is performed, after the fermentation is completed, filtration is performed to obtain the fermentation complex liquid.

[0010] Preferably, the fermentation temperature of the fermentation treatment is 38-42 DEG C, and the fermentation lasts for 1 h.

[0011] Preferably, the silica coating liquid is silica, silane coupling agent and silicone oil according to the weight ratio (3-5):1:(5-8).

[0012] Preferably, the silane coupling agent is silane coupling agent KH550.

[0013] The application further provides a repair gel containing mesenchymal stem cell exosome, which is prepared by the preparation method of the repair gel.

[0014] Compared with the prior art, the application has the following beneficial effects: The repair gel is prepared by using exosome freeze-dried powder, modified shell agent and silica coating liquid, and the modified shell agent and the silica coating liquid are well coordinated, so that the obtained repair gel product has excellent acne repair property and remarkable product moisturizing property, and the product realizes the coordinated improvement of acne repair property and moisturizing property, and has remarkable long-acting moisturizing effect. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0016] The preparation method of the mesenchymal stem cell exosome-containing repair gel in the embodiment comprises the following steps: uniformly blending exosome freeze-dried powder, modified shell agent and silicon dioxide coating liquid according to a weight ratio of 7-9:4-6:4 to obtain the repair gel.

[0017] The exosome freeze-dried powder in the embodiment is made of the prior art of CN113797151B One mesenchymal stem cell exosome-containing repair gel and a preparation method thereof Embodiment 1.

[0018] The preparation method of the modified shell agent in the embodiment is as follows: S01: heat-treating the shell powder at 130-140℃ for 1h, then cooling to 55℃ at a rate of 2-5℃ / min, and keeping the temperature; S02: preparation of the modification liquid: S02a: adding 2-4 parts of carboxymethyl cellulose and 1-3 parts of brown algae extract to 5-8 parts of a 5% mass fraction sodium citrate solution and stirring uniformly to obtain a brown algae composite liquid; S02b: mixing 2-5 parts of collagen and 4-7 parts of a fermentation composite liquid and ultrasonically treating, obtaining a collagen liquid after ultrasonic treatment, and uniformly blending and stirring the brown algae composite liquid and the collagen liquid according to a weight ratio of 5:3 to obtain a modification liquid; S03: stirring the heat-preserved shell powder in the modification liquid at 4-7 times the total amount of the heat-preserved shell powder, stirring for 2h at a stirring speed of 450-500r / min, and then filtering and drying to obtain the modified shell agent.

[0019] The ultrasonic power of the ultrasonic treatment in the embodiment is 350-400W, and the ultrasonic treatment is performed for 1h; the stirring speed of the stirring treatment is 450-500r / min, and the stirring treatment is performed for 2h.

[0020] The specific preparation method of the brown algae extract in the embodiment is as follows: The brown algae is crushed to 100 mesh, and then extracted in a sufficient amount of 95% ethanol solution at an extraction temperature of 65-70℃ for 5h, and then filtered to obtain an extract liquid, and then concentrated and dried to obtain the brown algae extract.

[0021] The preparation method of the fermentation composite liquid in the embodiment is as follows: Blend the shea butter, centella asiatica and silene root according to the weight ratio (2-4):5:(1-3) to obtain a mixed material, then add 10-15% of bacillus subtilis to the mixed material, and then perform fermentation treatment, filter after fermentation is completed to obtain a fermentation compound liquid.

[0022] The fermentation temperature of the fermentation treatment in this embodiment is 38-42℃, and the fermentation time is 1h.

[0023] The silica coating liquid in this embodiment is silica, silane coupling agent and silicone oil in a weight ratio of (3-5):1:(5-8).

[0024] The silane coupling agent in this embodiment is silane coupling agent KH550.

[0025] The preparation method of the mesenchymal stem cell exosome-containing repair gel in this embodiment is used to prepare the repair gel.

[0026] Embodiment 1. The preparation method of the mesenchymal stem cell exosome-containing repair gel in this embodiment comprises the following steps: blending exosome freeze-dried powder, modified shell agent and silica coating liquid according to a weight ratio of 7:4:4 to obtain a repair gel.

[0027] The exosome freeze-dried powder in this embodiment is prepared according to the prior art of CN113797151B, a mesenchymal stem cell exosome-containing repair gel and a preparation method thereof, embodiment 1.

[0028] The preparation method of the modified shell agent in this embodiment is as follows: S01: heat the shell powder at 130℃ for 1h, then cool it to 55℃ at a rate of 2℃ / min, and keep it at this temperature for a certain period of time; S02: preparation of the modification liquid: S02a: add 2 parts of carboxymethyl cellulose and 1 part of brown algae extract to 5 parts of a 5% mass fraction sodium citrate solution and stir until uniform to obtain a brown algae compound liquid; S02b: mix 2 parts of collagen and 4 parts of fermentation compound liquid and perform ultrasonic treatment, and then obtain a collagen liquid after ultrasonic treatment is completed; blend and stir the brown algae compound liquid and the collagen liquid according to a weight ratio of 5:3 to obtain a modification liquid; S03: stir the shell powder in the modification liquid at a rate of 450 / min for 2h, and then filter and dry to obtain a modified shell agent.

[0029] The ultrasonic power of the ultrasonic treatment in this embodiment is 350W, and the ultrasonic treatment time is 1h; the stirring speed of the stirring treatment is 450 / min, and the stirring time is 2h.

[0030] The specific preparation method of the brown algae extract in this embodiment is as follows: The brown algae is crushed to 100 meshes, then extracted in a sufficient amount of 95% ethanol solution, the extraction temperature is 65°C, the extraction time is 5h, after extraction, filtration is performed to obtain an extract, and then the extract is concentrated and dried to obtain a brown algae extract.

[0031] The preparation method of the fermentation complex liquid of the present embodiment is as follows: The Vaccinium vitis-idaea oil, Centella asiatica and Saposhnikovia divaricata root are uniformly blended according to a weight ratio of 2:5:1 to obtain a uniformly blended material, 10% of Bacillus subtilis is added to the uniformly blended material, and then fermentation treatment is performed, after which fermentation is completed, and filtration is performed to obtain a fermentation complex liquid.

[0032] The fermentation temperature of the fermentation treatment of the present embodiment is 38°C, and the fermentation time is 1h.

[0033] The silicon dioxide coating liquid of the present embodiment is silicon dioxide, silane coupling agent and silicone oil according to a weight ratio of 3:1:5.

[0034] The silane coupling agent of the present embodiment is silane coupling agent KH550.

[0035] The preparation method of the mesenchymal stem cell exosome-containing repair gel of the present embodiment is used to prepare the repair gel.

[0036] Embodiment 2. The preparation method of the mesenchymal stem cell exosome-containing repair gel of the present embodiment comprises the following steps: uniformly blending exosome freeze-dried powder, modified shell agent and silicon dioxide coating liquid according to a weight ratio of 9:6:4 to obtain a repair gel.

[0037] The exosome freeze-dried powder of the present embodiment is prepared according to the prior art of CN113797151B Mesenchymal stem cell exosome-containing repair gel and preparation method thereof Embodiment 1.

[0038] The preparation method of the modified shell agent of the present embodiment is as follows: S01: The shell powder is first heat-treated at 140°C for 1h, then cooled to 55°C at a rate of 5°C / min, and kept at 55°C for a certain period of time; S02: Preparation of a modification liquid: S02a: 4 parts of carboxymethyl cellulose and 3 parts of brown algae extract are added to 8 parts of a 5% sodium citrate solution and stirred uniformly to obtain a brown algae complex liquid; S02b: 5 parts of collagen and 7 parts of fermentation complex liquid are mixed and ultrasonically treated, and after ultrasonic treatment, a collagen liquid is obtained; the brown algae complex liquid and the collagen liquid are uniformly blended and stirred according to a weight ratio of 5:3 to obtain a modification liquid; S03: The heat-treated shell powder is stirred in 7 times the amount of the modification liquid, and after stirring, filtration and drying are performed to obtain a modified shell agent.

[0039] The ultrasonic power of the mixed ultrasonic treatment of this embodiment is 400W, and the ultrasonic treatment is performed for 1h; the stirring speed of the stirring treatment is 500r / min, and the stirring treatment is performed for 2h.

[0040] The specific preparation method of the brown algae extract of this embodiment is as follows: The brown algae is crushed to 100 meshes, and then extracted in a sufficient amount of 95% ethanol solution, the extraction temperature is 70℃, the extraction time is 5h, after the extraction is completed, filtration is performed to obtain an extract, and then the extract is concentrated and dried to obtain the brown algae extract.

[0041] The preparation method of the fermentation complex liquid of this embodiment is as follows: The milk fruit oil, centella asiatica and saposhnikovia divaricata root are uniformly blended according to a weight ratio of 4:5:3 to obtain a uniformly blended material, 15% of Bacillus subtilis is added to the uniformly blended material, and then fermentation treatment is performed, after the fermentation is completed, filtration is performed to obtain a fermentation complex liquid.

[0042] The fermentation temperature of the fermentation treatment of this embodiment is 42℃, and the fermentation is performed for 1h.

[0043] The silicon dioxide coating liquid of this embodiment is silicon dioxide, silane coupling agent and silicone oil according to a weight ratio of 5:1:8.

[0044] The silane coupling agent of this embodiment is silane coupling agent KH550.

[0045] The preparation method of the mesenchymal stem cell exosome-containing repair gel of this embodiment is used to prepare the repair gel.

[0046] Embodiment 3. The preparation method of the mesenchymal stem cell exosome-containing repair gel of this embodiment comprises the following steps: uniformly blending exosome freeze-dried powder, modified shell agent and silicon dioxide coating liquid according to a weight ratio of 8:54 to obtain a repair gel.

[0047] The exosome freeze-dried powder of this embodiment is prepared according to the prior art of CN113797151B Mesenchymal stem cell exosome-containing repair gel and preparation method thereof Embodiment 1.

[0048] The preparation method of the modified shell agent of this embodiment is as follows: S01: heat treatment of the shell powder at 135℃ for 1h, then cooling to 55℃ at a rate of 3.5℃ / min, and keeping the temperature; S02: preparation of the modification liquid: S02a: 3 parts of carboxymethyl cellulose and 2 parts of brown algae extract are added to 6.5 parts of 5% sodium citrate solution and stirred uniformly to obtain a brown algae complex liquid; S02b: 3.5 parts of collagen, 5.5 parts of fermentation complex liquid are mixed and ultrasonically treated, after ultrasonic treatment, collagen liquid is obtained; the complex liquid of brown algae and the collagen liquid are blended and stirred uniformly according to a weight ratio of 5:3 to obtain a modified liquid; S03: The heat-preserved shell powder is stirred in the modified liquid which is 5.5 times the total amount of the heat-preserved shell powder, and after stirring, filtration and drying, a modified shell agent is obtained.

[0049] The ultrasonic power of the ultrasonic treatment in this embodiment is 375 W, and the ultrasonic treatment is performed for 1 h; the stirring speed of the stirring treatment is 470 r / min, and the stirring treatment is performed for 2 h.

[0050] The specific preparation method of the brown algae extract in this embodiment is as follows: The brown algae is crushed to 100 mesh, and then extracted in a sufficient amount of 95% ethanol solution, the extraction temperature is 67℃, the extraction time is 5 h, after extraction, filtration is performed to obtain an extract, and then the extract is concentrated and dried to obtain a brown algae extract.

[0051] The preparation method of the fermentation complex liquid in this embodiment is as follows: The milk fruit oil, centella asiatica and saposhnikovia divaricata root are uniformly blended according to a weight ratio of 3:5:2 to obtain a uniformly blended material, 12.5% of the total amount of the uniformly blended material is added to the uniformly blended material, and then fermentation treatment is performed, after fermentation, filtration is performed to obtain a fermentation complex liquid.

[0052] The fermentation temperature of the fermentation treatment in this embodiment is 40℃, and the fermentation treatment is performed for 1 h.

[0053] The silicon dioxide coating liquid in this embodiment is silicon dioxide, silane coupling agent and silicone oil according to a weight ratio of 4:1:6.5.

[0054] The silane coupling agent in this embodiment is silane coupling agent KH550.

[0055] The preparation method of the mesenchymal stem cell exosome-containing repair gel in this embodiment is as follows:

[0056] Embodiment 4. The preparation method of the mesenchymal stem cell exosome-containing repair gel in this embodiment comprises the following steps: uniformly blending exosome freeze-dried powder, modified shell agent and silicon dioxide coating liquid according to a weight ratio of 7:5:4 to obtain a repair gel.

[0057] The exosome freeze-dried powder in this embodiment is prepared by the prior art of CN113797151B Mesenchymal stem cell exosome-containing repair gel and preparation method thereof Embodiment 1.

[0058] The preparation method of the modified shell agent in this embodiment is as follows: S01: The shell powder is first heat treated at 132℃ for 1h, then cooled to 55℃ at a rate of 3℃ / min, and kept at this temperature; S02: Preparation of the modification liquid: S02a: 3 parts of carboxymethyl cellulose and 2 parts of brown algae extract are added to 6 parts of a 5% mass fraction sodium citrate solution and stirred uniformly to obtain a brown algae compound liquid; S02b: 3 parts of collagen and 5 parts of a fermentation compound liquid are mixed and ultrasonically treated. After ultrasonic treatment, a collagen liquid is obtained. The brown algae compound liquid and the collagen liquid are blended and stirred uniformly at a weight ratio of 5:3 to obtain a modification liquid; S03: The heat-treated shell powder is stirred in a modification liquid that is 5 times the total amount of the heat-treated shell powder, and after stirring, it is filtered and dried to obtain a modified shell agent.

[0059] The ultrasonic power for the ultrasonic treatment in this example is 360W, and the ultrasonic treatment is performed for 1h. The stirring speed for the stirring treatment is 460r / min, and the stirring treatment is performed for 2h.

[0060] The specific preparation method of the brown algae extract in this example is as follows: The brown algae is ground to 100 mesh and then extracted in a sufficient amount of 95% ethanol solution at an extraction temperature of 68℃ for 5h. After extraction, the extract is filtered and concentrated and dried to obtain the brown algae extract.

[0061] The preparation method of the fermentation compound liquid in this example is as follows: The milk fruit oil, centella asiatica, and saposhnikovia divaricata root are blended uniformly at a weight ratio of 3:5:2 to obtain a blended material. Then, 12% of bacillus subtilis based on the total amount of the blended material is added to the blended material, and then fermentation treatment is performed. After fermentation, the fermentation compound liquid is obtained by filtration.

[0062] The fermentation temperature for the fermentation treatment in this example is 39℃, and the fermentation treatment is performed for 1h.

[0063] The silica coating liquid in this example is a mixture of silica, silane coupling agent, and silicone oil at a weight ratio of 4:1:5.

[0064] The silane coupling agent in this example is silane coupling agent KH550.

[0065] The preparation method of the mesenchymal stem cell exosome-containing repair gel in this example is as follows:

[0066] Comparative Example 1. The difference between this example and Example 3 is that no modified shell agent is added.

[0067] Comparative Example 2. The difference between this example and Example 3 is that no modification liquid is added during the preparation of the modified shell agent.

[0068] Comparative Example 3. Unlike Example 3, the modification liquid was not added with the brown algae extract.

[0069] Comparative Example 4. Unlike Example 3, the modification liquid was not added with the fermentation complex liquid.

[0070] Comparative Example 5. Unlike Example 3, the modification liquid was not added with the fermentation complex liquid.

[0071] The product performance test of Examples 1-4 and Comparative Examples 1-5, 100 volunteers of 20-35 years old with mild acne and similar symptoms were evenly distributed in each group, and the test product was used for testing. The significant efficiency = the number of significant effects / the number of tests, and the number of significant effects is the number of people with mild acne symptoms disappearing. The test results are as follows

[0072] From Examples 1-4 and Comparative Examples 1-5, it can be seen that the product of the present application can achieve long-term moisturizing and excellent acne treatment effect; the performance of the product is significantly deteriorated without adding the modified shell agent; the performance of the product is deteriorated without adding the modification liquid in the preparation of the modified shell agent, without adding the brown algae extract in the modification liquid, without adding the fermentation complex liquid in the modification liquid, and without adding the silica coating liquid in the product. The performance of the product is also deteriorated without adding the silica coating liquid in the product. The long-term moisturizing and excellent acne treatment effect of the product can be achieved by using the specific raw material ratio of the present application.

[0073] It is apparent for those skilled in the art that the present application is not limited to the details of the foregoing exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, and the scope of the present application should be defined by the appended claims rather than the above description, and it is intended to include all changes falling within the meaning and range of equivalents of the claims.

[0074] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be combined appropriately to form other embodiments that those skilled in the art can understand.

Claims

1. A method of preparing a mesenchymal stem cell exosome-containing repair gel, characterized by, Comprising the following steps: The exosome freeze-dried powder, modified shell agent and silicon dioxide coating liquid are blended uniformly according to the weight ratio (7-9): (4-6): 4 to obtain the repair gel.

2. The method of claim 1, wherein the method of preparing the mesenchymal stem cell exosome-containing repair gel is characterized by, The exosome freeze-dried powder is made of the prior art of CN113797151B A repair gel containing mesenchymal stem cell exosomes and its preparation method Example 1.

3. The method of claim 1, wherein the method of preparing the mesenchymal stem cell exosome-containing repair gel is characterized by, The preparation method of the modified shell agent is: S01: The shell powder is first heat treated at 130-140℃ for 1h, then cooled to 55℃ at a rate of 2-5℃ / min, and kept at this temperature; S02: Preparation of modification liquid: S02a: 2-4 parts of carboxymethyl cellulose and 1-3 parts of brown algae extract are added to 5-8 parts of 5% mass fraction sodium citrate solution and stirred uniformly to obtain a brown algae compound liquid; S02b: 2-5 parts of collagen and 4-7 parts of fermentation compound liquid are mixed and ultrasonically treated, and after ultrasonic treatment, a collagen liquid is obtained; the brown algae compound liquid and the collagen liquid are blended and stirred uniformly according to a weight ratio of 5:3 to obtain a modification liquid; S03: The heat-treated shell powder is stirred in the modification liquid at 4-7 times the total amount of the heat-treated shell powder, and after stirring, it is filtered and dried to obtain a modified shell agent.

4. The method of claim 3, wherein the method further comprises the step of adding a pharmaceutically acceptable carrier to the mixture of the mesenchymal stem cell exosomes and the pharmaceutically acceptable carrier. The ultrasonic power of the ultrasonic treatment is 350-400W, and the ultrasonic treatment is performed for 1h; the stirring speed of the stirring treatment is 450-500r / min, and the stirring treatment is performed for 2h.

5. The method of claim 3, wherein the method further comprises the step of adding a pharmaceutically acceptable carrier to the mixture. The specific preparation method of the brown algae extract is: The brown algae is crushed to 100 mesh, then extracted in sufficient 95% mass fraction ethanol solution at 65-70℃ for 5h, filtered after extraction, and then concentrated and dried to obtain the brown algae extract.

6. The method of claim 3, wherein the method further comprises the step of adding a pharmaceutically acceptable carrier to the mixture. The preparation method of the fermentation compound liquid is: The milkwood oil, centella asiatica and saposhnikovia divaricata root are blended uniformly according to a weight ratio of (2-4):5:(1-3) to obtain a mixed material, 10-15% of bacillus subtilis is added to the mixed material, then fermented, filtered after fermentation, and a fermentation compound liquid is obtained.

7. The method of claim 6, wherein the method further comprises the step of adding a pharmaceutically acceptable carrier to the mixture of the mesenchymal stem cell exosomes and the pharmaceutically acceptable carrier. The fermentation temperature of the fermentation treatment is 38-42℃, and the fermentation treatment is performed for 1h.

8. The method of claim 1, wherein the method of preparing the mesenchymal stem cell exosome-containing repair gel is characterized by, The silicon dioxide coating liquid is a mixture of silicon dioxide, silane coupling agent and silicone oil according to a weight ratio of (3-5):1:(5-8).

9. The method of claim 8, wherein the method further comprises the step of adding a pharmaceutically acceptable carrier to the mixture of the mesenchymal stem cell exosomes and the pharmaceutically acceptable carrier. The silane coupling agent is silane coupling agent KH550.

10. The repair gel prepared by the preparation method of any one of claims 1-9.

Images