Gel containing filament of Clania variegata and preparation method thereof

Abstract

The invention provides a novel application technology of the filament of the macromitra. The invention relates to a gel containing filament of Clania variegata and water.

Description

Technical Field

[0001] The present invention relates to a gel containing silk from a sedge moth and a method for producing the same. Background Art

[0002] Silk from the larvae of moths belonging to the family Psychidae in the order Lepidoptera (psychoptera), collectively known as psychedelic silk, possesses mechanical properties superior to those of silkworm silk and spider silk. For example, the elastic modulus of psychedelic silk from the tea moth (Eumeta minuscula) is 3.5 times that of silkworm silk and 2.5 times that of spider silk from the astilbe (Nephila clavata), demonstrating exceptional strength (Non-Patent Documents 1 and 2).

[0003] In terms of breeding, moths also have advantages over silkworms. For example, silkworms, in principle, only feed on the leaves of mulberry trees (Morus), such as mountain mulberry (M. bombycis), white mulberry (M. alba), and Lu mulberry (M. Ihou). Therefore, the breeding area and breeding period are determined by the supply of mulberry leaves and the time when the mulberry leaves bloom. On the other hand, moths are polyphagous and have low specificity for bait leaves, and can feed on leaves from a wide variety of tree species. Therefore, bait leaves are easy to obtain, and there is no need to select a breeding area. In addition, depending on the species, the leaves of evergreen trees can also be used as bait leaves. Therefore, unlike deciduous mulberry trees, bait leaves can be supplied year-round. Moreover, moths are smaller than silkworms, so the breeding space required for breeding is less than that of silkworms, making them easy to breed in large quantities. Therefore, compared with silkworms, breeding costs can be significantly reduced.

[0004] The moth also has an advantage over the silkworm in productivity. For example, silkworms produce large amounts of silk only during cocooning, with the entire cocoon-making process occurring during the same period. Consequently, the silk-collecting periods overlap, creating a problem of concentrated labor. Meanwhile, the moth repeatedly produces silk throughout its larval stage, both while building its nest and while migrating. Therefore, manually adjusting the silk-collecting period offers the advantage of distributing the labor period.

[0005] As mentioned above, silk from the moth has properties that surpass those of traditional animal fibers and offers many advantages in production, making it a promising environmentally friendly alternative to silk (Non-Patent Document 2). Furthermore, its use in fiber-reinforced composite materials combined with other polymers has also been reported (Patent Document 1).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2019-44117

[0009] Non-patent literature

[0010] Non-patent literature 1: Nature Communications (2019) 10: 1469

[0011] Non-patent document 2: Next technology Vol.39, N0.4 (2020): 14-17 Summary of the Invention

[0012] Technical problem to be solved by the invention

[0013] However, previous technologies for applying the silk of the moth moth have only utilized the properties of the silk of the moth moth as a fiber.

[0014] Therefore, the technical problem of the present invention is to provide a new application technology of the silk of the moth.

[0015] Technical solutions to technical problems

[0016] Therefore, the inventors of the present invention conducted research to change the silk of the moth moth into a form other than a fiber form. As a result, they unexpectedly discovered that by heating a dispersion or aqueous solution containing the moth moth silk and then cooling it, and adjusting the water content as needed, a hydrogel (moth moth silk hydrogel) can be easily formed. The resulting hydrogel has excellent stability and formability and can be used in various technical fields, thus completing the present invention.

[0017] That is, the present invention provides the following inventions [1] to [6].

[0018] [1] A gel containing (i) silk from a sedge moth and (ii) water (hereinafter sometimes referred to as a sedge moth silk water-containing gel).

[0019] [2] The water-containing gel of worm silk according to [1], wherein the water content is 80% by mass or more and 99.99% by mass or less of the total amount of the gel.

[0020] [3] The water-containing gel of sedge moth silk as described in [1] or [2], further comprising one or more components selected from the group consisting of gel-forming polymers, sugars, sugar alcohols, alcohols, polyols, water-soluble polymers and alkaline substances.

[0021] [4] The water-containing gel of moth silk according to [1], wherein the moth silk is the silk of Eumeta japonica, Eumeta minuscula or Nipponopsyche fuscescens.

[0022] [5] Foods, pharmaceuticals, cosmetics, biomaterials, cushioning materials, elastic materials, fishing gear, medical devices, industrial materials, and sanitary materials containing the water-containing gel of the silk of the moth described in any one of [1] to [4].

[0023] [6] A method for producing a hydrogel containing silk from a sedge moth, which is used to produce the hydrogel containing silk from a sedge moth according to any one of [1] to [3], wherein the method is characterized in that an aqueous solution containing silk from a sedge moth is heated to 50°C or higher and then cooled.

[0024] Effects of the Invention

[0025] The sedge moth silk hydrogel of the present invention is a hydrogel formed from sedge moth silk having an extremely high elastic modulus and strength and water molecules. Its strength and other properties can be varied, and it can be used in a wide range of fields, including food, medicine, cosmetics, biomaterials, cushioning materials, elastic materials, fishing gear, medical devices, industrial materials, and sanitary materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a graph showing the evaluation results of the surface smoothness, shape stability, and appearance of the water-containing gel of the silk of the present invention obtained in Example 3. DETAILED DESCRIPTION

[0027] The present invention relates to a water-containing gel of sedge moth silk. One embodiment of the water-containing gel comprises (i) sedge moth silk and (ii) water.

[0028] In this specification, gel refers to a solid substance in a colloid-like liquid dispersion medium. Because it is solid, it lacks the fluidity of gases or liquids. Therefore, a gel is a substance that exhibits thixotropy—flow when subjected to shear stress but no flow when static.

[0029] In this specification, a hydrogel is a colloid in which the dispersion medium is water and is in a solid state. Specifically, it is a state in which a large amount of water is absorbed by a polymer in a network-like state.

[0030] The water-containing gel of the moth silk is a gel in which the moth silk has absorbed a large amount of water.

[0031] The main component of the aqueous gel of the present invention is Psychodon silk, which is a general term for silk derived from the larvae of moths belonging to the family Psychidae of the order Lepidoptera. More specifically, it is protein-based silk produced by Psychodon larvae.

[0032] The family Acanthopsychidae includes genera such as Acanthopsyche, Anatolopsyche, Bacotia, Bambalina, Canephora, Chalioides, Dahlica, Diplodoma, Eumeta, Eumasia, Kozhantshikovia, Mahasena, Nipponopsyche, Paranarychia, Proutia, Psyche, Pteroma, Siederia, Striglocyrbasia, Taleporia, Theriodopteryx, and Trigonodoma. However, the term "acanthopsyche" used herein may refer to a species belonging to any genus. Specific examples of acanthopsyche include Eumeta japonica, Eumeta minuscula, and Nipponopsychefus cescens. Larvae may range in age from the first to the last instar. However, if the goal is to obtain thicker and longer silk from the moth, larger moths are preferred. For example, within the same species, more advanced larvae are preferred, and between males and females, larger females are preferred. Furthermore, within the family of Moths, larger species are preferred. Therefore, the giant moth and the tea moth are suitable moth species.

[0033] In this specification, "worm silk" refers to silk derived from insects, specifically protein-based silk produced by insect larvae and adults for purposes such as nesting, locomotion, anchoring, cocooning, and hunting. Unless otherwise specified, references to "worm silk" in this specification refer to silk from the moth.

[0034] The silk of the moth in this specification includes single fibers, spun fibers and aggregated fibers.

[0035] "Single filament" refers to the smallest unit of filaments that make up a fiber, also known as a single filament. Single filaments are primarily composed of fibroin-like proteins. Silk produced by the moth naturally spins as a pair of filaments, and single filaments are not typically found. However, through a scouring process, adhering substances can be removed, resulting in single filaments.

[0036] "Spun silk fiber" refers to silk produced by the moth in its direct spinning state. Spinned silk fibers are composed of pairs of two single filaments. Their morphology is based on the fact that two single filaments, released from the moth's left and right spinning openings, are bound together by a sericin-like adhesive. Furthermore, in this specification, when the term "spun silk" is used together with "spun silk," such as "spun moth silk" or "spinning moth silk," it generally refers to the spinned silk fiber.

[0037] "Collective fibers" refer to fibers composed of multiple fiber bundles, also known as multifilaments. These are so-called raw silk, which in principle consists of multiple single fibers. However, in this specification, this also includes fibers composed of multiple single fibers and spun fibers, or multiple spun fibers. The collective fibers in this specification refer to collective fibers composed solely of silk from the moth. The collective fibers are twisted through the twisting process to form stronger silk threads. However, the collective fibers in this specification include not only twisted silk fibers but also untwisted silk fibers that feel soft and smooth to the touch.

[0038] There are two types of silk threads of the moth: support silk threads and nest silk threads. "Support silk threads" refer to the silk threads spun by the moth before it moves, and they function as a support (foothold) to prevent it from falling from branches or leaves during movement. The moth usually uses this support silk thread as a foothold, and moves in the direction of travel while hooking the claws of its two legs. In order to make it easier for the moth to hook the left and right legs, and to distribute the fixed part of the silk thread or the load on the silk thread to the left and right, the support silk threads are spun in a zigzag shape. On the other hand, "nest silk threads" are the silk threads that make up the nest, and they are spun to splice leaf or branch fragments, or to make the inner wall of the nest, which serves as a living area, a comfortable environment. In principle, support silk threads are thicker than nest silk threads and are also mechanically stronger.

[0039] The method for obtaining the silk of the moth is not particularly limited, and is preferably produced by the method described in Japanese Patent Application Laid-Open No. 2018-197415. Alternatively, the modified silk of the moth produced by genetically modified silkworms described in International Publication No. 2018 / 074403 can be used.

[0040] As described in Non-Patent Documents 1 and 2, silk from the moth has a unique amino acid sequence and a highly ordered hierarchical structure. This unique amino acid sequence and highly ordered hierarchical structure result in fibers with both excellent elastic modulus and strength.

[0041] The silk of the moth moth is formed by a fibril hierarchy with nanofibrils as basic units composed of a repeating long-period structure of a crystalline phase and an amorphous phase. The repeating unit of the primary structure is about 160 residues, which is about 5 times longer than spider silk. The biggest feature of the moth moth silk is that it has a hybrid type of polyalanine sequence and Gly-Gly-X (X is Ala, Tyr, etc.) sequence that are characteristic of spider silk, and Gly-X (X is Ala, Ser, etc.) that is characteristic of silkworms. The number of amino acid residues in the crystalline phase is believed to be 67 residues, which is several times longer than other silks (such as the silk of the amber silkworm). The length of the period of the crystalline phase and the amorphous phase (long period), which serves as the benchmark for the length of the crystalline phase, is also several times longer than that of other silks. In the formation of aqueous gels, the areas where such crystalline phases are easily formed are believed to form physical cross-linked structures, and the formation of a strong cross-linked structure is also believed to affect the strength of the gel.

[0042] Water molecules are believed to be concentrated in the amorphous region during hydrogel formation. As mentioned above, the primary structure consists of 160 repeating units, of which 67 form the crystalline phase, resulting in an amorphous phase of approximately 90 residues. Water molecules are believed to be concentrated in these 90 residues of amorphous regions.

[0043] The sedge moth silk hydrogel of the present invention contains water as a solvent or dispersion medium. The water content in the gel can be adjusted appropriately based on the desired strength and functionality of the hydrogel and the properties of other additives, as long as the gel is formed at 25°C and atmospheric pressure.

[0044] The water content in the hydrogel is preferably 80% by mass or more and 99.99% by mass or less of the total amount of the gel, from the perspective of forming a gel at 25°C under atmospheric pressure. Furthermore, it is more preferably 85% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more. Furthermore, it is more preferably 99.95% by mass or less, even more preferably 99.9% by mass or less, and even more preferably 99.5% by mass or less.

[0045] The mass ratio (a / b) of the moth silk (a) to water (b) varies depending on the strength and functionality of the hydrogel, as well as the properties of other additives, and is preferably from 0.0001 to 0.1765, more preferably from 0.0005 to 0.1111, and even more preferably from 0.005 to 0.0417.

[0046] In order to prepare an aqueous solution containing the silk of the moth, in addition to water, an aqueous solvent that is conducive to dissolving the moth silk can also be used. As an aqueous solvent, a solution formed by dissolving a neutral salt in water can be listed, such as a copper-ethylenediamine aqueous solution, a copper hydroxide-ammonia aqueous solution, a copper hydroxide-alkali-glycerol aqueous solution, a lithium bromide aqueous solution, a calcium chloride aqueous solution, a magnesium chloride aqueous solution, a zinc chloride aqueous solution, a calcium nitrate aqueous solution, a magnesium nitrate aqueous solution, a zinc nitrate aqueous solution, a calcium thiocyanate aqueous solution, a magnesium thiocyanate aqueous solution, a zinc thiocyanate aqueous solution, a sodium thiocyanate aqueous solution, a lithium thiocyanate aqueous solution, an urea aqueous solution, a sodium lauryl sulfate aqueous solution, etc. In addition, an aqueous alcohol formed by mixing a lower alcohol such as methanol and / or ethanol in water can also be used. In addition, from the viewpoint of dissolving the moth silk, organic solvents such as hexafluoroacetone, dichloroacetic acid, trifluoroacetic acid, hexafluoroisopropanol, hexafluoroacetone, and formic acid can also be used.

[0047] The sedge moth silk hydrogel of the present invention contains, in addition to the sedge moth silk as a solute and dispersoid and water as a solvent and dispersion medium, various additives may be contained in consideration of the strength of the hydrogel and the desired functions and properties.

[0048] Examples of additives that may be contained include components having a high affinity for moth silk and water, gel-forming polymers, sugars, sugar alcohols, alcohols, polyols, water-soluble polymers, plasticizers, basic compounds such as organic bases and inorganic bases, and pigments.

[0049] Examples of gel-forming polymers include synthetic polymers such as poly(meth)acrylic acid, poly(meth)acrylates, carboxyvinyl polymers, polyvinyl chloride, polyvinyl acetate, or salts thereof, and natural polymers such as cellulose derivatives and polysaccharides (agar, gelatin, carrageenan, pectin, gellan gum, xanthan gum, locust bean gum, tamarind seed gum, and thermogellan).

[0050] Examples of sugars include monosaccharides, oligosaccharides, and oligosaccharides. Examples of sugar alcohols include thitol, lactitol, maltitol, mannitol, sorbitol, and xylitol. Examples of alcohols include ethanol, isopropanol, and butanol. Examples of polyols include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glycerol, polyglycerol, butylene glycol, and polybutylene glycol.

[0051] Examples of the water-soluble polymer include polyvinyl alcohol and the like.

[0052] Examples of the plasticizer include triacetin, triethylene glycol diacetate, acetyl tributyl citrate, dibutyl sebacate, epoxy soybean oil, phthalic acid esters, and adipate esters.

[0053] In addition, basic compounds such as organic bases and inorganic bases function as cross-linking agents for acidic polymers such as polyacrylic acid.

[0054] Examples of the coloring matter include Edible Red No. 2, Edible Red No. 3, Edible Red No. 40, Edible Red No. 102, Edible Red No. 106, Edible Yellow No. 4, Edible Yellow No. 5, Edible Blue No. 1, Edible Blue No. 2, and caramel.

[0055] These other components have different effects on the hydrogel of the present invention depending on their types, and therefore their content varies greatly. However, the content is preferably from 0.5% by mass to 60% by mass, more preferably from 1% by mass to 45% by mass, and even more preferably from 5% by mass to 30% by mass, relative to the total amount of the gel.

[0056] The aqueous gel containing silkworm silk of the present invention can be easily produced, for example, by heating an aqueous solution or dispersion containing silkworm silk (hereinafter, the aqueous solution or dispersion containing silkworm silk may also be simply referred to as the silkworm silk-containing aqueous solution) to 50°C or higher and then cooling it. If necessary, the silkworm silk-containing aqueous solution may be concentrated by dialysis, ultrafiltration, or other methods before heating.

[0057] In the method for producing an aqueous gel containing silk from the present invention, an aqueous solution or dispersion containing silk from the moth is first prepared. The aqueous solution containing silk from the moth can be produced by adding a sufficient amount of water to the silk from the moth and, if necessary, additives. The additives may be added simultaneously with the water or separately.

[0058] The heating temperature of the aqueous solution containing worm silk is sufficient to be 50° C. or higher, more preferably 60° C. or higher. The upper limit of the heating temperature may be 100° C. or higher, but is preferably 130° C. or lower in consideration of industrial productivity.

[0059] About heating conditions, if the concentration of the moth silk changes significantly in the stage of gelation of the moth silk aqueous solution, it will be difficult to obtain the gel with target properties, so it is preferably set to prevent the condition of water evaporation in gelation and the condition that water molecules can have accessibility inside and outside the solution or gel.If such conditions are considered, it is preferably heated in a container (mould) that is limited to a certain degree of water permeability containing the moth silk aqueous solution.As the container (mould) for heating, it is not particularly limited, and the container of dialysis membrane, low-density polyethylene container, metal container etc. can be enumerated.In addition, heating can be heated in water or in air.

[0060] After sufficient gelation is confirmed, the mixture is cooled to 15 to 25° C., thereby obtaining the water-containing gel of the silk of the present invention.

[0061] Furthermore, for example, when the container is a dialysis membrane, the amount of water in the gel can be adjusted by appropriately changing the solvent of the external liquid in the container.

[0062] Furthermore, even when the aqueous solution of silk was heated for a long time (80°C for 500 minutes) and then cooled, no gel was obtained. Therefore, the method for producing gel containing silkworm moths of the present invention is industrially advantageous.

[0063] In addition, when preparing the water-containing gel of the silk of the present invention, not only the silk of the silk moth can be used, but also a protein having an amino acid sequence constituting the silk of the silk moth or a protein having an amino acid sequence obtained by deleting, adding and / or replacing one or more amino acids in the amino acid sequence based on a known method can be used.

[0064] By adding other ingredients (additives) such as polyvinyl alcohol and agar to the aqueous solution containing the silkworm moth, heating it to 50°C or higher, and then cooling it, a composite hydrogel composed of the silkworm moth, polyvinyl alcohol, and agar can be obtained. The resulting hydrogel has the properties of maintaining its soft shape and exhibiting resilience. Furthermore, using a dialysis membrane as a container minimizes water evaporation and prevents deformation due to adhesion to the container.

[0065] The sedge moth silk hydrogel of the present invention can also be transformed into a thixotropic gel by adjusting the water content and adding other components (additives) during gelation. The gel is solid at 15-25°C but develops fluidity upon application of shear force. Such a gel can be used as a pharmaceutical, cosmetic, or food product.

[0066] In addition, a solid but elastic hydrogel can be produced. Such a gel can be used as food, cosmetics, biomaterials, cushioning materials, elastic materials, fishing gear, medical equipment, industrial materials, sanitary materials (diapers, etc.), etc.

[0067] Example

[0068] Next, the present invention will be described in further detail with reference to Examples, but the present invention is not limited to these Examples.

[0069] Example 1

[0070] As the silk of the moth, the support silk of the moth was used and scouring was carried out in a 0.02M sodium carbonate aqueous solution heated to 90°C for 30 minutes. After 40 mg of the scouring moth silk was dissolved in a saturated lithium thiocyanate aqueous solution heated to 70°C for 60 minutes, it was placed in a cellulose dialysis tube and dialyzed using 2 liters of ultrapure water as the dialysis external solution. The dialysis temperature was set to 4°C, and the dialysis external solution was replaced twice a day for a total of 4 times. The prepared moth silk aqueous solution was calculated to have a concentration of 1.2% by mass by dry weight. The obtained moth silk aqueous solution was placed in a cellulose dialysis tube, air-dried and concentrated, thereby preparing a 2% by mass moth silk aqueous solution. The obtained aqueous solution was placed in a dialysis tube and heated in a warm bath at 38°C to 80°C. The relationship between heating time and gelation is shown in Table 1. As shown in Table 1, the aqueous solution containing silk from the moth is easily gelled when heated to 50°C or higher.

[0071] Furthermore, the 2 mass % silk aqueous solution did not gel even when heated at 80° C. for 500 minutes.

[0072] [Table 1]

[0073]

[0074] Example 2

[0075] A 2% by mass aqueous solution of scutellaria silk was sealed in a dialysis membrane, a low-density polyethylene (LDPE) film, a sealed container (sample tube with a lid), or an open container (petal dish). The solution was heated for 20 minutes under the conditions shown in Table 2, and the resulting gel was observed. The water heating and dry heat (bath) temperature were set at 80°C. Dry heat treatment was performed in a dry heat sterilizer at 80°C for 20 minutes, while autoclaving was performed at 121°C for 20 minutes. The results are shown in Table 2.

[0076] As can be seen from Table 2, the heating conditions are such that water evaporation is prevented during gelation, and the conditions for water molecules to flow freely inside and outside the film (container) are good.

[0077] [Table 2]

[0078]

[0079] Example 3

[0080] 1 mL of aqueous solutions of 0.005, 0.01, 0.05, 0.07, 0.1, 0.5, 0.75, 1, 2, 4, 5, 6, and 7 mass % scutellaria silk prepared in the same manner as in Example 1 were enclosed in an 8 / 32 dialysis membrane along with air bubbles and heated in 90°C hot water for 15 minutes. After heating, gelation was determined by the movement of air bubbles when the dialysis membrane was inverted. The dialysis membrane was then cut open and the gel morphology evaluated.

[0081] The degree of gelation was determined based on the movement of air bubbles enclosed in the dialysis membrane. The evaluation criteria were as follows.

[0082] ×: No change from before heating was observed.

[0083] △: Movement is slightly slower than before gelation.

[0084] ○: Movement is slower than before gelation.

[0085] ◎: The movement of bubbles stops in the gel or the bubbles are stationary.

[0086] The results are shown in Table 3.

[0087] [Table 3]

[0088] Concentration of silk from the moth (mass %) Gelation form 0.005 × liquid 0.01 △ liquid 0.05 ○ liquid 0.07 ◎ liquid 0.1 ◎ liquid 0.5 ◎ Semi-solid 0.75 ◎ Solid State 1 ◎ Solid State 2 ◎ Solid State 4 ◎ Solid State 5 ◎ Solid State 6 ◎ Solid State 7 ◎ Solid State

[0089] ※Degree of gelation:◎>○>△>×

[0090] Example 4

[0091] 10% by mass of polyvinyl alcohol aqueous solution 1mL and agar 100mg were placed in a 5mL sample tube and vigorously stirred with a vortex mixer to disperse. 1mL of 2% by mass of sedge moth silk aqueous solution was added and mixed evenly by blowing. The mixed solution was sealed in a dialysis membrane, immersed in a 90°C water bath and heated for 30 minutes, and then further transferred to a saturated borax aqueous solution heated to 90°C and heated for 30 minutes. The moisture was removed, and after cooling at 4°C for 5 minutes, the dialysis membrane was cut open and the gel was recovered.

[0092] The resulting gel was evaluated for surface smoothness, shape stability, and appearance. Surface smoothness evaluated the roughness of the gel surface and the presence of peeling. Shape stability evaluated the presence of the dialysis membrane container shape and the presence of peeling from the membrane attachment. Appearance evaluated transparency, gloss, and other characteristics.

[0093] The results are expressed in Figure 1 .

[0094] Depend on Figure 1 It was found that the composite aqueous gel of the present invention's silk, polyvinyl alcohol, and agar was obtained, and that the composite aqueous gel had excellent surface smoothness, shape stability, and appearance.

[0095] Furthermore, the polyvinyl alcohol was not dissolved by adding it to the dialysis membrane and heating it in water. Since it came into contact with the borax solution, excess water escaped from the gel, causing the membrane to shrink and tighten. This achieved a three-stage gel structure formation: gelation of the silkworm, gelation of the polyvinyl alcohol, and gelation of the agar.

[0096] Test Example 1 Comparison of Physical Properties of Cotton Moth Silk Gel and Silk-Containing Hydrogel

[0097] An experiment was conducted to compare the physical properties of a hydrogel containing silkworm silk, which is a silk-spinning insect similar to the sedge moth, and the sedge moth silk-containing hydrogel of the present invention.

[0098] A 2% by mass aqueous solution of sedge moth silk and a 2% by mass aqueous solution of silkworm silk were prepared by the same method as in Example 1, and 2 mL of each was sealed in an 8 / 32 dialysis membrane.

[0099] The resulting dialysis membrane was placed in a 50 mL tube containing 40 mL of ultrapure water, which had been previously heated at 100°C in a dry heat unit. The membrane was heated to form a gel. The heating process in water was continued until gelation occurred. The gel was cut into 10 mm lengths and subjected to a uniaxial compression test (load cell: 50 N, indenter: The base was set to Z = 0, and the position where F>0.03N was defined as the height of the gel, and the compression rate was measured to 70% at 1 mm / min (n = 9).

[0100] The compressive modulus was calculated from the stress and strain at a strain of 0.05 to 0.25%, and the results are shown in Table 4 from the time until the initial gel destruction.

[0101] [Table 4]

[0102]

[0103] It can be seen that the sedge moth silk hydrogel has extremely excellent physical properties, with a compressive elastic modulus of 0.8 times, a toughness of 6.0 times, a breaking displacement of 2.3 times, and a compressive failure stress of 3.7 times, compared with the silk hydrogel.

Claims

1. A gel, characterized in that contain: (i) silk from the moth and (ii) water.

2. The gel according to claim 1, wherein: The water content is 80% by mass or more and 99.99% by mass or less in the total amount of the gel.

3. The gel according to claim 1, wherein: It further contains one or more components selected from the group consisting of gel-forming polymers, sugars, sugar alcohols, alcohols, polyols, water-soluble polymers, and alkaline substances.

4. The gel according to claim 1, wherein: The silk of the moth is the silk spun by the giant moth (Eumeta japonica), the giant tea moth (Eumeta minuscula) or the sesame moth (Nipponopsyche fuscescens).

5. A food, medicine, cosmetic, sanitary material, biomaterial, cushioning material, elastic material, fishing gear, medical device or industrial material containing the gel according to any one of claims 1 to 4.

6. A method for producing a gel, for producing the gel according to claim 1, wherein: The aqueous solution containing the silk of the moth is heated to 50°C or higher and then cooled.

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