WO2023112804A1 - Fibrous structure, scaffold material for cultured meat, and method for manufacturing fibrous structure - Google Patents

Abstract

The present invention provides a novel fibrous structure suitable for culturing cells. The fibrous structure 1 of the present invention contains a fiber 5. The fibrous structure 1 has a porous structure and an apparent density of 0.04 g/cm3 or less. The fibrous structure 1 is in the shape of, for example, a sheet. The sheet-shaped fibrous structure 1 has, for example, a single layer structure with a thickness of 3 mm or more. The method for manufacturing the fibrous structure 1 of the present invention includes contacting a sheet-shaped structure, which comprises a gelatinous fiber 6 containing water, with an alcohol.

Description

Fiber structure, scaffolding material for cultured meat, and method for producing fiber structure

The present invention relates to a fibrous structure, a scaffolding material for cultured meat, and a method for producing a fibrous structure.

In recent years, it is expected that the demand for meat will increase as the world's population increases. In order to meet the future increase in meat demand, it is not enough to simply increase the production efficiency of conventional protein sources, and it is essential to develop new protein sources. New protein sources include vegetable meat produced from plants, meat produced from insects, cultured meat produced by culturing microorganisms or cells themselves, and the like. “Vegetable meat” is a processed food made by adding additives to vegetable protein such as soybeans as a raw material, and is also called “fake meat”. “Cultured meat” means meat produced by culturing muscle cells using regenerative medicine technology, and is also called “cultured meat” or “clean meat”.

One of the benefits of cultured meat is its safety. For example, in the process of meat production and processing, there is always the risk of contamination with pathogens that cause food poisoning. However, since cultured meat is cultivated in almost sterile conditions, the risk of contamination with pathogenic bacteria is low. In addition, cultured meat can not only reduce the cost of the processing process, but it is also attracting attention from an environmental point of view, as research results show that it can reduce greenhouse gases by 96% compared to conventional production methods. At present, minced meat has been reported as cultivated meat.

Japanese Patent Application Laid-Open No. 2020-79460

In order to produce chunks of meat of a certain size, such as steak, sashimi, and fillets, it is necessary to use scaffolding materials to three-dimensionally culture cells such as muscle cells. Scaffolds for culturing cells include, for example, fibrous structures such as fibrous sheets. As an example, Patent Document 1 discloses a fiber assembly that can be used for cell culture. In the field of cultivated meat, new fiber structures suitable for culturing cells are desired.

Therefore, an object of the present invention is to provide a new fiber structure suitable for culturing cells.

The present invention
A fibrous structure comprising fibers,
Provided is a fibrous structure having a porous structure and an apparent density of 0.04 g/cm ³ or less.

Furthermore, the present invention provides
Provided is a cultivated meat scaffold comprising the fiber structure.

Furthermore, the present invention provides
Provided is a method for producing a fibrous structure, comprising contacting a structure having gel-like fibers containing water with alcohol.

According to the present invention, a new fiber structure suitable for culturing cells can be provided.

It is an image which shows an example of the fiber structure of this embodiment. It is a scanning electron microscope (SEM) image showing an example of an end surface of the fiber structure of the present embodiment. FIG. 4 is a diagram for explaining the shape of fibers in a fiber structure; FIG. 4 is a diagram for explaining the shape of fibers in a fiber structure; It is a SEM image which shows an example of the surface of the fiber structure of this embodiment. 5 is a graph for explaining a method of examining the state of orientation of fibers contained in a fiber structure; 4C is a diagram for explaining the relationship between the angles θ ₁ and θ ₂ shown in the graph of FIG. 4B and the fibers included in the fiber structure; FIG. It is a figure for demonstrating the manufacturing method of a fiber structure. It is a figure for demonstrating the manufacturing method of a fiber structure. 4 is an SEM image showing the surface of the fiber structure of Example 5. FIG. 10 is an SEM image showing the surface of the fiber structure of Example 6. FIG.

The fiber structure according to the first aspect of the present invention comprises
A fibrous structure comprising fibers,
It has a porous structure and an apparent density of 0.04 g/cm ³ or less.

In the second aspect of the present invention, for example, the fiber structure according to the first aspect is sheet-like.

In the third aspect of the present invention, for example, the fiber structure according to the second aspect has a single layer structure.

In the fourth aspect of the present invention, for example, the fiber structure according to the second or third aspect has a thickness of 3 mm or more.

In the fifth aspect of the present invention, for example, in the fiber structure according to any one of the first to fourth aspects, the fibers have an average fiber diameter of 1 μm or more.

In the sixth aspect of the present invention, for example, in the fiber structure according to any one of the first to fifth aspects, the fibers are oriented.

In the seventh aspect of the present invention, for example, in the fiber structure according to any one of the first to sixth aspects, in the graph created by the following test method, the first peak and the second peak different from the first peak There are 2 peaks.
Test method: Observe the surface of the fiber structure with a scanning electron microscope. The obtained electron microscope image is binarized to create a binarized image. A power spectrum is obtained by Fourier transforming the binarized image. The angular distribution of the average amplitude is calculated from the power spectrum, and a graph is created in which the horizontal axis is the angle and the vertical axis is the average amplitude.

In the eighth aspect of the present invention, for example, in the fiber structure according to the seventh aspect, the difference between the angle θ ₁ corresponding to the apex of the first peak and the angle θ ₂ corresponding to the apex of the second peak is 70° to 130°.

In the ninth aspect of the present invention, for example, in the fiber structure according to any one of the first to eighth aspects, the fibers contain polysaccharides.

In the tenth aspect of the present invention, for example, in the fiber structure according to any one of the first to ninth aspects, the fibers contain alginic acid and/or alginate.

In the eleventh aspect of the present invention, for example, the fiber structure according to any one of the first to tenth aspects is edible.

In the twelfth aspect of the present invention, for example, the fiber structure according to any one of the first to eleventh aspects includes an adhesion improver that improves adhesion of cells, and further includes a coating layer that coats the fibers. have.

In the thirteenth aspect of the present invention, for example, the fiber structure according to any one of the first to twelfth aspects is used as a substrate for culturing cells.

The cultivated meat scaffolding material according to the fourteenth aspect of the present invention comprises
A fiber structure according to any one of the first to thirteenth aspects is provided.

A method for manufacturing a fiber structure according to the fifteenth aspect of the present invention comprises:
It involves contacting a structure having gelatinous fibers containing water with an alcohol.

In the sixteenth aspect of the present invention, for example, in the production method according to the fifteenth aspect, the alcohol is ethanol.

In the seventeenth aspect of the present invention, for example, the manufacturing method according to the fifteenth or sixteenth aspect comprises winding the gel-like fibers around a bobbin to produce a wound body, and obtaining the sheet-like structure. and cutting the winding so as to.

In the eighteenth aspect of the present invention, for example, in the manufacturing method according to the seventeenth aspect, the gel-like fibers are wound around the bobbin while being traversed.

In the 19th aspect of the present invention, for example, in the manufacturing method according to the 18th aspect, the ratio of the number of traverses per second to the rotation speed (rps) of the bobbin is 0.25-5.

In the twentieth aspect of the present invention, for example, the production method according to any one of the fifteenth to nineteenth aspects comprises ejecting a solution containing a polysaccharide and water from a nozzle, and and contacting the discharge from the nozzle with a coagulating liquid.

Although the details of the present invention will be described below, the following description is not intended to limit the present invention to specific embodiments.

(fiber structure)
As shown in FIG. 1 , the fiber structure 1 of this embodiment includes fibers 5 . Specifically, the fiber structure 1 is an assembly of multiple fibers 5 . The fibrous structure 1 may consist essentially of the fibers 5 alone. The fiber structure 1 is typically sheet-like. However, the fiber structure 1 may be block-shaped. In this specification, the sheet-like fiber structure 1 is sometimes referred to as a "fiber sheet 1".

The fiber structure 1 typically has a flat plate shape and has two pairs of end faces facing each other. In this embodiment, the direction X is, for example, the direction from one of the pair of end faces of the fiber structure 1 to the other. The direction Y is, for example, a direction orthogonal to the direction X, and is a direction from one of the other pair of end faces of the fiber structure 1 to the other.

The fiber structure 1 has a porous structure. Specifically, in the fiber structure 1, spaces exist between the fibers 5, and the spaces can be regarded as pores. The pores included in the fiber structure 1 are continuous pores that are continuously formed in a three-dimensional shape. In the fibrous structure 1, the holes penetrate the fibrous structure 1, for example. In the fiber structure 1, the fibers 5 and the spaces between the fibers 5 all have relatively uniform sizes.

In the fiber structure 1 of this embodiment, the spaces between the fibers 5 are large and the apparent density is small. In this embodiment, the fiber structure 1 has an apparent density of 0.04 g/cm ³ or less. The fiber structure 1 having such a small apparent density is suitable for culturing cells in spaces between the fibers 5 . In other words, the fiber structure 1 has a space of a size suitable for culturing cells therein. In addition, in the fiber aggregate of Patent Document 1, the fibers are welded and fixed at the portions where the fibers intersect. In Patent Document 1, it is difficult to adjust the apparent density of the fiber assembly to 0.04 g/cm ³ or less.

The apparent density of the fiber structure 1 can be measured according to Japanese Industrial Standards (former Japanese Industrial Standards; JIS) K7222:2005. The apparent density of the fiber structure 1 is 0.03 g/cm ³ or less, 0.025 g/cm ³ or less, 0.023 g/cm 3 or less, 0.020 g/cm ^{3 or} less, 0.018 g/cm ³ or less, and further may be 0.015 g/cm ³ or less. The lower limit of the apparent density of the fiber structure 1 is not particularly limited, and is, for example, 0.005 g/cm ³ and may be 0.010 g/cm ³ .

The porosity of the fiber structure 1 is not particularly limited, and is, for example, 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, and further may be 90% or more. The upper limit of the porosity of the fiber structure 1 is not particularly limited, and is, for example, 99%. The porosity of the fibrous structure 1 can be calculated from the following formula based on the volume V (cm ³ ), weight W (g) and true density D (g/cm ³ ) of the fibrous structure 1 . In addition, the true density D means the specific gravity of the material forming the fiber structure 1 .
Porosity (%) = 100 × (V-(W / D)) / V

A sheet-like fiber structure (fiber sheet) 1 has, for example, a single layer structure. The fiber sheet 1 having a single-layer structure tends to be difficult to fibrillate in a liquid such as a culture medium. However, the fiber sheet 1 may have a laminated structure in which a plurality of layers made of fibers are laminated.

The thickness of the sheet-like fiber structure (fiber sheet) 1 is not particularly limited, and is, for example, 0.5 mm or more, 1 mm or more, 3 mm or more, 5 mm or more, 8 mm or more, 10 mm or more, and further 12 mm or more. may As an example, the fiber sheet 1 has a single layer structure and a thickness of 3 mm or more. The upper limit of the thickness of the fiber sheet 1 is not particularly limited, and may be, for example, 500 mm, 100 mm, or 50 mm. It is particularly preferable that the thickness of the fiber sheet 1 is 10 mm to 15 mm.

As an example, the length L X of the fiber structure 1 in the direction _X and the length L _Y of the fiber structure 1 in the direction Y are each greater than the thickness of the fiber structure 1 . The length L _X of the fiber structure 1 is not particularly limited, and is, for example, 10 mm to 1000 mm, and may be 100 mm to 500 mm. The length L _Y of the fiber structure 1 is not particularly limited, and is, for example, 10 mm to 500 mm, and may be 50 mm to 200 mm.

The fiber structure 1 is typically edible. In the present specification, "the fiber structure is edible" means that the fiber structure is composed only of substances approved as foods or food additives according to the laws and regulations of each country.

The shape of the fibers 5 in the fiber structure 1 is not particularly limited. Fibers 5 are preferably long fibers, but may be short fibers. Fiber 5 preferably does not have a branched structure. As shown in FIG. 2, the fibers 5 may have a flattened cross-section. In addition, FIG. 2 shows an example of an SEM image when the end face of the fiber structure 1 is observed in the direction X. As shown in FIG.

The average fiber diameter of the fibers 5 is not particularly limited. The upper limit of the average fiber diameter is not particularly limited, and may be, for example, 100 μm, 50 μm, or 30 μm. The average fiber diameter can be specified by the following method. First, the surface of the fiber structure 1, typically the main surface (the surface having the widest area), is observed by SEM. The enlargement magnification at this time is, for example, 300 times. In the obtained electron microscope image, the outer diameter of the specific fiber 5 is measured with a vernier caliper. An arbitrary number (at least 15) of the outer diameters of the fibers 5 are measured, and the average value of the obtained measured values is regarded as the average fiber diameter.

3A and 3B are schematic diagrams showing the outer shape of the fiber structure 1 in plan view and the shape of one fiber 5 included in the fiber structure 1. FIG. Other fibers have been omitted from FIGS. 3A and 3B for illustrative purposes. As shown in FIGS. 3A and 3B, in the fiber structure 1, the fibers 5 extend, for example, in the direction X, and more specifically, extend in the direction X while undulating in the direction Y. As shown in FIGS. The corrugations F formed by the undulating fibers 5 have, for example, smooth curves and form crests and valleys in the Y direction. Wavelength W _L (distance between two adjacent crests in direction X) of waveform F is not particularly limited, and may be, for example, 10 mm to 1000 mm, or 100 mm to 500 mm. A ratio R ₁ of the length _{L X} (mm) of the fiber structure 1 in the direction X to the wavelength W L (mm) is, for example, 0.25 to 5, preferably 0.5 to 3, and more preferably is between 0.75 and 1.5. Note that FIG. 3A shows a configuration in which the ratio R ₁ is 0.75. FIG. 3B shows a configuration in which the ratio R ₁ is 1.5.

The height W _H of the waveform F (the distance between peaks and valleys in the direction Y) matches the length L _Y of the fiber structure 1 in the direction Y, for example. The height W _H of the waveform F is not particularly limited, and is, for example, 10 mm to 500 mm, and may be 50 mm to 200 mm.

As an example, in the fiber structure 1, each of the plurality of fibers 5 extends in the direction X while undulating in the direction Y. As shown in FIG. Such a configuration of fibers 5 is suitable for reducing the apparent density of fiber structure 1 . The plurality of waveforms F formed by each of the plurality of fibers 5 may have the same wavelength W _L and may also have the same height W _H . These waveforms F may have the same size and shape as each other, except that their starting points are shifted. In this embodiment, it is preferable that at least two fibers 5 cross each other when the fiber structure 1 is viewed from above. At this intersection, the two fibers 5 are preferably not welded and not fixed. However, as long as the fiber structure 1 has an apparent density of 0.04 g/cm ³ or less, the two fibers 5 may be welded together at the intersection.

In the fiber structure 1, the fibers 5 are preferably oriented. When the fibers 5 are oriented, cultured meat produced using the fiber structure 1 has tissue density and hardness comparable to those of muscle fibers, and tends to achieve a good texture. Whether or not the fibers 5 are oriented can be confirmed, for example, from a graph prepared by the following test method. First, the surface of the fiber structure 1, typically near the center of gravity of the main surface, is observed with a scanning electron microscope (SEM). The enlargement magnification at this time is, for example, 300 times. As a result, an electron microscope image (for example, FIG. 4A) displaying a range of about 1000 μm in length×about 1000 μm in width is obtained. The vertical direction of this electron microscope image matches the direction X, for example. Next, the obtained electron microscope image is binarized to create a binarized image. A power spectrum is obtained by Fourier transforming the binarized image. The angular distribution of the average amplitude is calculated from the obtained power spectrum, and a graph (for example, FIG. 4B) is created with the angle on the horizontal axis and the average amplitude on the vertical axis. When a peak is confirmed in this graph, it can be determined that the fibers 5 are oriented in the fiber structure 1 . For details on how to create the graph above, see Enomae, T., et al, "Nondestructive Determination of Fiber Orientation Distribution of Paper Surface by Image Analysis", Nordic Pulp and Paper Research Journal 2006, Vol. 21, p. 253. -259. The graph can be created using known software, for example, the fiber orientation analysis program "FiberOri8single03" published by the Environmental Materials Science Laboratory, Biomaterials Engineering Division, University of Tsukuba. Multiple SEM images may be used to create the graph.

As shown in FIG. 4B, the graph created by the above test method preferably has a first _peak P ₁ and a second peak P ₂ different from the first peak P 1 . In this specification, the angle corresponding to the vertex _T1 of the first peak _P1 may be called the angle _θ1 , and the angle corresponding to the vertex _T2 of the second peak _P2 may be called the angle _θ2 . In the above graph, the presence of the first peak P ₁ and the second peak P ₂ means that the fiber structure 1 is oriented at an angle θ ₁ with respect to a specific direction (for example, the direction X). and fibers 5 oriented at an angle θ ₂ are present. Specifically, as shown in FIG. 4C, in the fiber structure 1, the fibers 5a are oriented at an angle θ ₁ and the fibers 5a are oriented at an angle θ ₂ It can be said that the fibers 5b and 5b are present. 4C is a schematic diagram showing the surface of the fiber structure 1. FIG. Other fibers are omitted in FIG. 4C for illustration purposes.

The angle θ ₁ corresponding to the vertex T ₁ of the first peak P ₁ is not particularly limited, and is within the range of 10° to 60°, for example. The angle θ ₂ corresponding to the vertex T ₂ of the second peak P ₂ is not particularly limited, and is within the range of 120° to 170°, for example. The difference between the angles θ ₁ and θ ₂ is, for example, 70° to 130°, preferably 70° to 110°. The difference between the angles θ ₁ and θ ₂ is preferably about 90°. In this case, the number of intersections between the fibers 5 increases, which tends to further reduce the apparent density.

From another aspect of the present invention,
A fiber structure 1 comprising fibers 5,
In the graph created by the test method below, there are a first peak P ₁ and a second peak P ₂ different from the first peak P ₁ ,
A fiber structure ₁ is provided in which the difference between the angle θ ₁ corresponding to the vertex T ₁ of the first peak P ₁ and the angle θ ₂ corresponding to the vertex T 2 of the second peak P ₂ is 70° to 130°. do.
Test method: Observe the surface of the fiber structure 1 with a scanning electron microscope. The obtained electron microscope image is binarized to create a binarized image. A power spectrum is obtained by Fourier transforming the binarized image. The angular distribution of the average amplitude is calculated from the power spectrum, and a graph is created in which the horizontal axis is the angle and the vertical axis is the average amplitude.

The fiber 5 contains, for example, an edible material. Edible materials include, for example, polysaccharides; proteins such as gelatin and collagen; lipids such as beeswax, phospholipids and fatty acids. The edible material is preferably a polymeric compound, ie an edible polymer. The weight average molecular weight of the edible polymer is not particularly limited, and is, for example, 1000 or more.

The fiber 5 preferably contains polysaccharide as an edible material. The fibers 5 preferably contain alginic acid and/or alginate as polysaccharide. Alginic acid is a polysaccharide contained in seaweeds and the like, and has a structural unit (M block) derived from β-D-mannuronic acid and a structural unit (G block) derived from α-L-guluronic acid. In alginic acid, each structural unit is linked via a 1,4-glycosidic bond. The content of G blocks in alginic acid is not particularly limited, and is, for example, 30 mol % or more, preferably 40 mol % or more, and more preferably 50 mol % or more. The upper limit of the G block content may be 90 mol % or 80 mol %. The content of G blocks may be from 31 mol % to 63 mol %.

The alginate contained in the fiber 5 is, for example, a salt of alginic acid and a divalent metal ion. For example, in alginate, at least one G block contained in alginic acid forms an ionic bond with a divalent metal ion. In other words, in the alginate contained in the fiber 5, alginic acid partially forms a salt with divalent metal ions. Alginates, for example, have a crosslinked structure via divalent metal ions. Examples of divalent metal ions include calcium ions, barium ions, iron ions, zinc ions, copper ions, and aluminum ions, with calcium ions being preferred.

The total value of the alginic acid content and the alginate content in the fiber 5 is not particularly limited, and is, for example, 50 wt% or more, preferably 60 wt% or more, more preferably 80 wt% or more, and 90 wt% or more. or more. The upper limit of this total value is not particularly limited, and is, for example, 95 wt%. As used herein, "content in fiber" means content based on dry fiber unless otherwise specified. By "dry state" is meant that the water content in the fiber is 1 wt% or less.

The fibers 5 may contain other polysaccharides P than alginic acid and alginate together with alginic acid and/or alginate or instead of alginic acid and/or alginate. Other polysaccharides P include carrageenan, glucomannan (konnyakumannan), chitosan, chitin, and the like. The fibers 5 preferably contain carrageenan as another polysaccharide P. Carrageenan, for example, functions as a softening agent that softens the fibers 5 .

Carrageenan is a polysaccharide extracted from red algae and has structural units derived from D-galactose sulfate. Carrageenan is classified into kappa carrageenan, iota carrageenan and lambda carrageenan according to the content of sulfate ester groups. In this embodiment, the fibers 5 preferably contain iota carrageenan.

Glucomannan is a polysaccharide contained in konjac yam and the like, and has a structural unit derived from glucose (glucose unit) and a structural unit derived from mannose (mannose unit). In glucomannan, each structural unit is linked via 1,4-glycosidic bonds. In glucomannan, the molar ratio of mannose unit to glucose unit is not particularly limited, and is, for example, 0.5 to 2, and may be 0.5 to 1.6.

The content of the other polysaccharide P in the fiber 5 is not particularly limited, and is, for example, 0.5 wt% or more, preferably 5 wt% or more, more preferably 10 wt% or more, and still more preferably 20 wt% or more. is. The upper limit of the content of other polysaccharide P is not particularly limited, and is, for example, 50 wt%.

The fibers 5 may further contain components other than polysaccharides. Other components include coagulants, softeners, lubricants, adhesion improvers described later, and the like. Coagulants include, for example, salts containing divalent metal ions. The salts include chlorides such as calcium chloride and carbonates such as calcium carbonate. Lubricants include glycerin and the like. The lubricant prevents the gelled fibers from coming into contact with free rollers, guides, and the like and rubbing off when the fiber structure 1 described later is produced, particularly when the gelled fibers, which are the precursors of the fibers 5, are wound. suitable for

The fiber structure 1 may further have a coating layer that covers the fibers 5. The coating layer may cover the entire surface of the fiber 5 or partially cover the surface of the fiber 5 . The coating layer contains, for example, an adhesion improver that improves the adhesiveness of cells, and is preferably composed substantially only of the adhesion improver. As mentioned above, the fibers 5 themselves may contain adhesion promoters as other ingredients.

The adhesion improver is preferably edible. The adhesion improver contains, for example, at least one selected from the group consisting of edible plant-derived components and edible animal-derived components. The adhesion improver may consist essentially of edible plant-derived components, or may consist essentially of edible animal-derived components.

As used herein, the term "edible plant-derived component" means an edible component made from a plant. The edible plant-derived component is not particularly limited, and is derived, for example, from plant seeds, roots, stems, leaves, and the like. The edible plant-derived component is preferably a seed-derived component.

The raw material of the edible plant-derived component is not particularly limited, and examples include leguminosae, grape family, gramineous family, asteraceae, palm family, cotton family, brassicaceae, poppy family, sesame family, rose family, oleaceae, mallow. plants belonging to the family, Pinaceae, Polygonaceae, Ericaceae, Currantaceae, Zingiberaceae, etc., preferably leguminous plants or grape family plants, more preferably leguminous plants. The raw material of the edible plant-derived component is preferably a leguminous plant seed, more preferably a soybean seed (soybean).

Edible plant-derived ingredients are, for example, ingredients processed from soybeans. The component obtained by processing soybeans is not particularly limited. Soy protein.

Defatted soybeans are soybeans from which oil has been removed. For example, they contain 50% or more protein, 35% or more carbohydrates, and 19% or less lipids by weight.

Defatted soymilk is a water-extracted fraction of defatted soybeans, and the dried fraction contains, for example, 59.0% or more protein, 26.9% or more carbohydrate, and 0.9% fat by weight. Including 2% or less.

Isolated soy protein is a protein separated from defatted soy milk by isoelectric precipitation or heating. %, containing 0.2-31% lipids.

Whey is a fraction obtained by removing separated soy protein from skimmed soy milk, and contains oligosaccharides and minerals.

Soybean meat is a product obtained by processing the water-insoluble components of defatted soymilk. Contains 5 to 2.8%.

Tofu cheese is defatted soymilk agglomerated with calcium ions and the like. .9%.

As used herein, the term "edible animal-derived ingredient" means an edible ingredient made from an animal. The edible animal-derived ingredients preferably include non-mortal animal-derived ingredients. "Non-lethal animal-derived ingredient" means an animal-sourced ingredient that can be obtained without slaughtering an animal. Raw materials for non-lethal animal-derived components include, for example, animal milk, eggs, blood, crop milk and the like, preferably animal milk or eggs.

Animal milk is not particularly limited, and examples include cow, goat, sheep, buffalo, camel, donkey, horse, reindeer, and yak milk, preferably cow milk (milk). The edible animal-derived component derived from milk is not particularly limited, and examples thereof include casein, whey, milk fat, lactose, vitamins, minerals, etc., preferably casein or whey. Casein is, for example, sodium caseinate.

The animal eggs are not particularly limited, and examples include chicken, quail, duck, ostrich, and pigeon eggs, preferably chicken eggs (chicken eggs). An egg is, for example, an unfertilized egg. Edible animal-derived components derived from eggs are not particularly limited, and examples thereof include egg yolk, egg white, ovalbumin, egg yolk lecithin, eggshell membrane, and the like.

The coating layer may or may not be gelled. A gelled coating layer can constitute a strong film. Ungelled coating layers tend to be relatively brittle.

In the fiber structure 1, the weight ratio of the adhesion improver to the weight of the fibers 5 is, for example, 0.01 wt% or more, may be 0.1 wt% or more, or may be 1 wt% or more. The upper limit of this ratio is not particularly limited, and is, for example, 50 wt%, may be 30 wt%, or may be 10 wt%. The adhesion promoter allows cells to easily adhere to the fiber structure 1 . While culturing cells on the fiber structure 1, some or all of the adhesion promoter may flow out or elute into the culture medium of the cells.

(Manufacturing method of fiber structure)
The method for manufacturing the fiber structure 1 of this embodiment includes:
It involves contacting a structure having gelatinous fibers containing water with an alcohol.

A structure having gel-like fibers is typically sheet-like. However, this structure may be block-shaped. In this specification, a sheet-like structure having gel-like fibers is sometimes referred to as a "sheet-like structure". A sheet-like structure can be produced, for example, using a production apparatus 100 shown in FIG. The manufacturing apparatus 100 includes a discharge section 10 for discharging a solution S containing an edible material (especially polysaccharide) and water, a solidification section 20 for containing a coagulation liquid 21 for solidifying the discharge from the discharge section 10, and a solidification section 20. A winding section 30 for winding the gel-like fibers 6 formed in the above is provided. The discharging part 10, the solidifying part 20, and the winding part 30 are arranged in this order along the direction in which the gel-like fibers 6 are wound by the winding part 30, for example. Note that the direction in which the gel-like fibers 6 are wound typically coincides with the direction X described above.

The ejection unit 10 has a storage unit 11 that stores the solution S and a nozzle 13 that ejects the solution S. As the discharge part 10, a commercially available syringe pump type discharge device or the like can be used. The solution S contained in the container 11 contains edible materials (especially polysaccharides) and water, as described above. Polysaccharides include alginates and other polysaccharides P described above. Alginates contained in the solution S include, for example, salts of alginic acid and alkali metal ions such as sodium ions and potassium ions, and sodium alginate is preferred. The alginate added to solution S is typically substantially free of divalent metal ions. The polysaccharide concentration in the solution S is not particularly limited, and is, for example, 0.05 wt % to 5 wt %. Solution S may further include softeners, lubricants, adhesion promoters, and the like.

In the ejection section 10 , the solution S is sent from the storage section 11 to the nozzle 13 and ejected from the ejection port of the nozzle 13 to the outside of the ejection section 10 . The ejection speed of the solution S from the nozzle 13 is not particularly limited, and is, for example, 0.1 to 100 mL/min. The size of the ejection port of the nozzle 13 can be appropriately adjusted according to the outer diameter of the target fiber 5 . The nozzle 13 may have a plurality of ejection openings. In this case, by solidifying the ejected material ejected from the nozzle 13, a plurality of gel-like fibers 6 can be produced at once. The number of ejection openings in the nozzle 13 is not particularly limited, and is, for example, 1-50. By using the nozzle 13 having a large number of ejection ports and setting the ejection speed of the solution S to be high, the gel-like fibers 6 can be efficiently produced, and the productivity is improved. The nozzle 13 is, for example, immersed in the coagulating liquid 21 contained in the coagulating section 20 .

The coagulating liquid 21 contained in the coagulating portion 20 can solidify the discharge by contacting the discharge discharged from the nozzle 13 . Gel-like fibers 6 are formed by solidifying the discharge from the nozzle 13 . The gel-like fiber 6 is hydrogel containing water derived from the solution S. The production method of the present embodiment includes, for example, ejecting a solution S containing an edible material (especially polysaccharide) and water from the nozzle 13, with the coagulation liquid 21 .

The coagulating liquid 21 is typically an aqueous solution containing a coagulant. The concentration of the coagulant in the coagulating liquid 21 is not particularly limited, and is, for example, 0.1 wt % to 10 wt %. The coagulant can be appropriately selected according to the edible material contained in the solution S (especially polysaccharides). As an example, when the solution S contains the above alginate, the coagulant is preferably a salt containing divalent metal ions. As the salt containing a divalent metal ion, those mentioned above can be used. The salt containing divalent metal ions dissolves in the coagulation liquid 21 to generate divalent metal ions. Divalent metal ions can form ionic bonds with the G blocks of alginate. Specifically, the metal ions (alkali metal ions) contained in the alginate are exchanged with divalent metal ions, thereby cross-linking a plurality of alginic acid molecules via the divalent metal ions. Due to this cross-linking reaction, gelling of the ejected material ejected from the nozzle 13 proceeds, and the gelled fibers 6 are obtained.

The cross-linking reaction of multiple alginic acid molecules via divalent metal ions is usually an irreversible reaction. Therefore, the gel-like fibers 6 obtained by the above method are difficult to return to the solution S. As a result, the fiber structure 1 made from this gel-like fiber 6 tends to be excellent in heat resistance. When the fibrous structure 1 is excellent in heat resistance, cultured meat produced using this fibrous structure 1 as a scaffold easily maintains its shape even when cooked. Thus, the fiber structure 1 having excellent heat resistance is particularly suitable as a scaffolding material for cultured meat for cooking.

The gel-like fibers 6 formed in the coagulating section 20 are sent to the winding section 30 . The manufacturing apparatus 100 may further include free rollers 40 and 41 for sending the gelled fibers 6 to the winding section 30 . The free roller 40 is placed, for example, in the coagulating liquid 21 and is separated from the nozzle 13 by about 1 m. Gel-like fibers 6 pass through free rollers 40 and are sent to the outside of solidifying section 20 . The gelatinous fibers 6 sent to the outside of the solidifying section 20 are sent to the winding section 30 after passing through the free rollers 41 .

The winding section 30 has a bobbin 31 for winding the gel-like fibers 6 formed in the coagulating section 20 and a guide 35 for traversing the gel-like fibers 6 when winding the gel-like fibers 6 . FIG. 6 is a schematic perspective view showing the configuration of the bobbin 31 and guide 35. As shown in FIG. As shown in FIG. 6, the bobbin 31 has a columnar or cylindrical shape. The direction in which the bobbin 31 extends typically coincides with the direction Y described above. The bobbin 31 is configured to be rotatable in the winding direction (direction X) of the gel-like fibers 6 by a motor, for example. The outer diameter of the bobbin 31 is not particularly limited, and is, for example, 100 mm to 1000 mm. The length of the bobbin 31 in the direction Y is not particularly limited, and is, for example, 10 mm to 500 mm.

The guide 35 has, for example, a columnar or cylindrical shape. The guide 35 extends in the direction (direction Y) in which the bobbin 31 extends. The length of the guide 35 in the Y direction is smaller than the length of the bobbin 31 in the Y direction. The guide 35 is formed with a groove 36 extending in the winding direction (direction X) of the gel-like fiber 6 . The number of grooves 36 in the guide 35 is not particularly limited, and is, for example, 1-10. The guide 35 is configured to be reciprocable in the direction Y, for example, by a motor. In the winding section 30 , the gel-like fibers 6 can be traversed by reciprocating the guide 35 in the direction Y while the gel-like fibers 6 are passed through the grooves 36 .

In the manufacturing method of the present embodiment, by using the guide 35, the gel-like fiber 6 can be wound around the bobbin 31 while being traversed. The traversal is preferably performed such that the waveform F described with reference to FIGS. 3A and 3B is formed. A ratio R ₂ of the number of traverses per second to the revolutions per second (rps) of the bobbin 31 is, for example, 0.25 to 5, preferably 0.5 to 3, and more preferably 0. 0.75 to 1.5. The number of traverses per second means the number of times the guide 35 reciprocates in the direction Y in one second. The ratio R ₂ typically coincides with the above-described ratio R ₁ (the ratio of the length L _X (mm) of the fiber structure 1 in the direction X to the wavelength W _L (mm)).

The rotation speed of the bobbin 31 is not particularly limited, and is, for example, 0.1 to 10 rps. The winding speed of the gelled fibers 6 by the bobbin 31 is not particularly limited, and is, for example, 0.1 to 50 m/min. The number of traverses per second is not particularly limited, and is, for example, 0.1-10. The traverse speed is not particularly limited, and is, for example, 10 to 500 mm/sec. The traverse speed means the average speed of the reciprocating motion of the guide 35 in the Y direction.

By winding the gel fiber 6 around the bobbin 31, a wound body of the gel fiber 6 can be produced around the bobbin 31. A sheet-like structure having the gel-like fibers 6 can be obtained by cutting the wound body along the direction Y using a knife such as scissors. Thus, the manufacturing method of the present embodiment includes, for example, winding the gel-like fibers 6 around the bobbin 31 to produce a wound body, and cutting the wound body so as to obtain a sheet-like structure. further comprising: The sheet-like structure has, for example, the same shape and dimensions as the fiber structure 1 except that it has gel-like fibers 6 instead of the fibers 5 described above. Note that excess water may be removed from the wound body before cutting the wound body. A slit for cutting the wound body may be formed in the bobbin 31 .

Note that the manufacturing method of the present embodiment may further include a washing step of washing the gel-like fibers 6 before and/or after producing the sheet-like structure. The washing step is performed, for example, before contacting the sheet-like structure with alcohol. The cleaning liquid used in the cleaning step is typically water. The temperature of the cleaning liquid is, for example, room temperature. The time for which the gel-like fibers 6 are brought into contact with the cleaning liquid is not particularly limited, and is, for example, 1 minute to 1 hour. According to the washing process, salts containing divalent metal ions such as calcium chloride adhering to the surface of the gel-like fibers 6 can be removed.

As an example, the cleaning process may be performed using a cleaning tank (not shown) disposed between the solidifying section 20 and the winding section 30 and containing cleaning liquid. According to the washing tank, the gel-like fibers 6 sent from the coagulating section 20 can be washed by bringing them into contact with the washing liquid. Gel-like fibers 6 that have been washed are sent from the washing tank to a winding section 30 and wound on a bobbin 31 . The washing step may be performed by applying a washing liquid to the wound body produced by winding the gel-like fibers 6 around the bobbin 31, or by immersing the wound body together with the bobbin 31 in the washing liquid. Furthermore, the washing step may be performed by immersing the sheet-like structure in a washing liquid. At this time, a nylon mesh or the like may be arranged at the bottom of the container containing the cleaning liquid.

As described above, the manufacturing method of the present embodiment includes bringing a structure (sheet-like structure) having gel-like fibers 6 into contact with alcohol. The method of bringing the sheet-like structure into contact with alcohol is not particularly limited. As an example, the sheet-like structure may be brought into contact with alcohol by immersing the sheet-like structure in liquid L containing alcohol. The alcohol concentration in the liquid L is, for example, 50 wt % or higher, preferably 70 wt % or higher, and even more preferably 90 wt % or higher. The liquid L may consist essentially of alcohol. The liquid L may further contain water in addition to alcohol. The temperature of the liquid L is, for example, room temperature. The time for which the sheet-like structure is immersed in the liquid L is not particularly limited, and is, for example, 1 minute to 1 hour. As the alcohol, for example, a lower alcohol having 5 or less carbon atoms can be used, preferably ethanol.

The manufacturing method of the present embodiment further includes, for example, contacting the structure (sheet-like structure) having gel-like fibers 6 with alcohol and then drying the sheet-like structure. Drying conditions for the sheet-like structure are not particularly limited. As an example, the sheet-like structure may be dried by allowing the sheet-like structure to stand at room temperature. However, the sheet-like structure may be heated during the drying of the sheet-like structure. By drying the sheet-like structure, the solvent (alcohol or water) is removed from the sheet-like structure, and the fiber structure 1 is obtained.

In the manufacturing method of the present embodiment, water contained in the gel-like fibers 6 is replaced with alcohol by bringing the structure having the gel-like fibers 6 into contact with alcohol. According to studies by the present inventors, in a state in which the water contained in the gel-like fibers 6 is replaced with alcohol, the gel-like fibers 6 are sufficiently suppressed from being welded or bound together. When the structure is dried in this state, the fiber structure 1 of the present embodiment having a large space between the fibers 5 and a low apparent density can be obtained.

In the manufacturing method of the present embodiment, for example, before drying the structure having the gel-like fibers 6, the structure having the gel-like fibers 6 is cut into a predetermined shape, and/or the structure having the gel-like fibers 6 is dried. A cutting step of cutting the dried product into a predetermined shape may be further included after the treatment. According to the cutting process, the fiber structure 1 having a shape suitable for producing cultivated meat can be produced.

The production method of the present embodiment may further include applying an adhesion improver that improves the adhesion of cells to the dried product obtained by drying the structure having gel-like fibers 6. The coating layer described above can be formed by applying an adhesion improver to the dried product. As the adhesion improver, those described above can be used.

The adhesion improver can be applied, for example, by spraying an aqueous solution containing the adhesion improver onto the dried object. The adhesion improver may be applied by immersing the dried product in an aqueous solution containing the adhesion improver.

After applying the adhesion improver, you may wipe off excess water and heat dry. The drying temperature is not particularly limited, and is, for example, 50°C or higher, typically 90°C. The drying time is not particularly limited, and is, for example, 30 minutes or more, typically 1 hour.

(Characteristics and use of fiber structure)
As described above, the fiber structure 1 of this embodiment has an apparent density of 0.04 g/cm ³ or less. In the fiber structure 1 having such a small apparent density, the space between the fibers 5 is large, and cells can be easily cultured in the space. The fiber structure 1 also tends to allow the culture solution for culturing the cells to easily permeate inside. Thus, it can be said that the fiber structure 1 of the present embodiment is suitable for culturing cells. According to the fibrous structure 1, a sufficient amount of cells can be easily cultured inside the fibrous structure 1, whereby, for example, sufficiently large cultured meat can be easily produced.

The fiber structure 1 of this embodiment is used, for example, as a base material for culturing cells. The fibrous structure 1 is particularly suitable for use as a scaffold material for cultivated meat. From another aspect, the present invention provides a cultivated meat scaffold comprising the fiber structure 1 . However, the fiber structure 1 of the present embodiment can also be used for applications other than the scaffold material for cultured meat, such as foods other than cultured meat, chemical products, and medicines.

The present invention will be described in more detail below with examples and comparative examples, but the present invention is not limited to these.

(Example 1)
First, distilled water was added to a 1000 mL disposable cup (square type) and stirred with a three-one motor having a stirring blade attached to the tip of the shaft. The rotation speed of the three-one motor was set to approximately 600 rpm. The amount of distilled water added was adjusted so that the total weight of the materials added to the cup was 100 parts by weight. Next, 1.6 parts by weight of powdered sodium alginate (Kimika Co., Ltd., Kimika Algin I-3G) and 0.4 parts by weight of powdered iota carrageenan (manufactured by Unitec Foods) were added to the cup little by little in this order. , dissolved in water. Further, 4.7 parts by weight of a glycerin aqueous solution with a concentration of 84 to 87 wt % (Kenei Pharmaceutical Co., Ltd., Glycerin P "Kenei") was added. As a result, an aqueous solution (solution S) containing sodium alginate and iota carrageenan as polysaccharides was prepared.

Next, using the manufacturing apparatus 100 described above, a sheet-like structure was produced by the following method. First, a syringe pump type discharge device was prepared as a discharge part of the manufacturing apparatus. A multi-hole nozzle was used as the nozzle of the ejection part. The multi-hole nozzle had 10 ejection openings with a diameter of 0.1 mm. Next, the above aqueous solution was injected into the accommodating portion of the ejection portion, and the aqueous solution was ejected from the nozzle. The ejection speed of the aqueous solution from the nozzle was set to 3 mL/min. After confirming that the aqueous solution was discharged from the nozzle, the nozzle was immersed in the coagulating liquid contained in the coagulating portion. A calcium chloride aqueous solution with a concentration of 2 wt % was used as the coagulating liquid.

The discharge from the nozzle was solidified by contact with the solidifying liquid. This formed gel-like fibers. This gel-like fiber was grasped by hand, passed through a free roller and a guide, and set on a bobbin of a winding section. The free roller placed in the coagulation liquid was 1 m away from the nozzle. The bobbin had an outer diameter of 100 mm and a length in direction Y of 150 mm.

Next, the bobbin and guide were driven to wind the gel-like fiber. At this time, the bobbin winding speed was set to 8 m/min, and the traverse speed was set to 64 mm/sec. The gelled fiber was wound on a bobbin such that the length of the wound body in the direction Y was about 100 mm. The ratio of traverses per second to bobbin revolutions (rps) was 0.75.

When the amount of gel-like fibers corresponding to 200 mL of the aqueous solution was wound up, the ejection of the aqueous solution from the nozzle was stopped. A wound body of gel-like fibers was formed around the bobbin. Extra moisture was removed from the roll by placing a kimtowel on top of the roll and squeezing with a hand roller. A sheet-like structure was obtained by cutting the wound body with scissors using a slit provided in the bobbin.

Next, 800 mL of ethanol (manufactured by Kishida Chemical Co., Ltd., ethanol 99.5, special grade) was added to the plastic container, and a nylon mesh was placed on the bottom of the container. By placing the above sheet-like structure on a nylon mesh, the sheet-like structure was immersed in ethanol for 5 minutes. As a result, the water contained in the gel-like fibers of the sheet-like structure was replaced with ethanol. The fiber structure (fiber sheet) of Example 1 was obtained by air-drying the sheet-like structure.

(Example 2)
A fiber structure (fiber sheet) of Example 2 was obtained in the same manner as in Example 1, except that the discharge of the aqueous solution from the nozzle was stopped at the stage of winding the gel-like fibers in an amount corresponding to 300 mL of the aqueous solution. .

(Example 3)
A fiber structure (fiber sheet) of Example 3 was obtained in the same manner as in Example 1, except that the traverse speed was set to 128 mm/sec. In Example 3, the ratio of traverses per second to bobbin revolutions (rps) was 1.5.

(Example 4)
A fiber structure (fiber sheet) of Example 4 was obtained in the same manner as in Example 1, except that the sheet-like structure was not immersed in ethanol.

(Example 5)
A conventional non-woven fabric (Sobu Sun Flat No. 1, manufactured by Alcare Co., Ltd.) composed of fibers containing alginate was prepared as the fiber structure (fiber sheet) of Example 5.

(Example 6)
A conventional non-woven fabric composed of fibers containing alginate (alginate non-woven fabric manufactured by Kimika Co., Ltd.) was prepared as the fiber structure (fiber sheet) of Example 6.

[Layer structure]
The end surfaces of the fiber sheets of Examples 1 to 6 were observed with an SEM to confirm the layer structure. As a result, the fiber sheets of Examples 1-4 had a single layer structure. The fiber sheets of Examples 5 and 6 had a laminated structure in which multiple layers of fibers were laminated. In Examples 5 and 6, the thickness of the layer composed of fibers was 0.1-0.2 mm.

[Apparent density]
The volume and weight of the fiber sheets of Examples 1 to 6 were measured, and the apparent density was calculated from the measured values obtained.

[SEM Observation of Surface]
The surfaces of the fiber sheets of Examples 1 to 6 were observed by SEM. The SEM image in FIG. 4A corresponds to the SEM image of the surface of the fiber sheet of Example 1. Figures 7 and 8 are SEM images showing the surfaces of the fibrous sheets of Examples 5 and 6, respectively.

[Fiber Orientation]
For the fiber sheets of Examples 1-3, 5 and 6, the SEM images of the surface were used to generate a graph of the average amplitude according to the test method described above, from which it was confirmed whether or not the fibers were oriented. The graph was created using the fiber orientation analysis program "FiberOri8single03". The graph of FIG. 4B is created from the SEM image of the surface of the fiber sheet of Example 1. From the graph of FIG. 4B, it can be confirmed that the first peak _P1 and the second peak _P2 are present. In this graph, the angle θ ₁ corresponding to the vertex T ₁ of the first peak P ₁ is 20°, _{the angle θ 2 corresponding to the vertex T 2 of} the second peak P 2 is 135°, and the angle θ ₁ and The difference from the angle θ ₂ was 115°.

[Space between fibers]
The end surfaces of the fiber sheets of Examples 1 to 6 were observed with an SEM to observe the spaces between the fibers. In addition, the condition of the space was evaluated according to the following criteria.
◯: Spaces between fibers all have a relatively uniform size.
x: The size of the space between the fibers is non-uniform.

[Fibrillation]
The fibrous sheets of Examples 1 to 6 were evaluated for defibration properties by the following method. First, a dry fiber sheet is prepared. The surface of the fiber sheet is pinched with tweezers, and stress is applied in the direction away from the fiber sheet. The state of the fiber sheet at this time was visually confirmed, and the defibration property was evaluated as follows.
◯: Almost no delamination between layers can be observed in the fiber sheet.
x: Peeling between layers is confirmed for the fiber sheet.

[Cell affinity]
(Culture test)
The fiber sheet of Example 1 was evaluated for cell affinity by the following method. First, a dry fiber sheet was cut with scissors into 3 cm squares and prepared. Next, a 3 cm square fiber sheet was immersed for 5 minutes in a solution containing New Fuji Pro SEH (manufactured by Fuji Oil Co., Ltd.) as an adhesion improver at a concentration of 1 wt %. As a result, the fibers contained in the fiber sheet were coated with the adhesion improver to form a coating layer composed of the adhesion improver. A disc having a diameter of 6 mm was punched out from the fiber sheet on which the coating layer was formed to obtain a test piece.

Next, the test piece was sterilized by being immersed in a 70 w/w % ethanol aqueous solution and allowed to stand for 30 minutes. After that, ethanol was removed from the test piece by washing with ultrapure water three times. This specimen was placed in a 96-well plate (Nunc® MicroWell® 96-Well #167008). Next, medium (DMEM (High glucose) D6546 (manufactured by Sigma-Aldrich)), L-glutamine (L-Glu 25030081 (manufactured by Thermo Fisher Scientific)), fetal bovine serum (FBS 10270 (manufactured by Thermo Fisher Scientific) )), and penicillin-streptomycin (#168-23191 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)). In the medium, the final concentration of L-glutamine was 4 mmol/L, the final concentration of fetal bovine serum was 10 wt%, and the final concentration of penicillin streptomycin was 100 units/mL. Next, 100 μL of the prepared medium was added to each well and allowed to stand for about 15 minutes, and the medium that did not permeate the test piece was removed. Next, a cell solution containing NIH3T3 cells, mouse fetal skin cells, was slowly added dropwise at a density of 1×10 ⁵ to 1×10 ⁷ cells/cm ² and allowed to stand for 30 minutes. Furthermore, the culture medium was replenished in an amount sufficient for the test piece to be immersed, and culture was started under conditions of 37° C. in a 5% CO ₂ atmosphere. One day after the initiation of culture, the test piece was transferred to a new plate, and culture was continued for a total of 7 days at 37°C in a 5% CO ₂ atmosphere by exchanging the medium every 3 days.

(Evaluation of cell number by CTG assay)
By the method described above, a well plate containing a test piece after one day from the start of culture and a well plate containing a test piece after three days from the start of culture were prepared. Next, 100 μL of a cell number evaluation reagent (CellTiter-Glo (registered trademark) 2.0 Cell Viability Assay G9243 (manufactured by Promega)) was added to each well and gently stirred for about 2 minutes. 200 μL of supernatant from each well was transferred to a 96-well plate (Perkin Elmer, OptiPlate-96 #6005299) for luminescence measurement. Next, the luminescence of the supernatant was measured according to the standard protocol for luminescence measurement of a plate reader (manufactured by Perkin Elmer, EnSight), and the number of cells was calculated from a calibration curve prepared in advance. Cell numbers were determined by an automated cell counter Thermo Countess® II FL. Based on the measurement results, the ratio of the cell number after 3 days to the cell number after 1 day from the start of culture was calculated. The calculated cell number ratio was 238%.

As can be seen from Table 1, the fiber sheets of Examples 1 to 3, which were produced by contacting the sheet-like structure with alcohol, had smaller apparent densities than the fiber sheet of Example 4. The apparent densities of the fibrous sheets of Examples 1-3 were lower than the fibrous sheets of Examples 5 and 6, which were conventional nonwoven fabrics. A fiber structure having an apparent density as low as 0.04 g/cm ³ or less has large spaces between fibers, and cells can be easily cultured in the spaces. In fact, in Example 1, cells could be cultured while the fiber sheet was coated with the adhesion promoter. Thus, it can be said that a fiber structure with a low apparent density is suitable for culturing cells.

As described above, the fiber sheets of Examples 5 and 6 had a laminated structure in which a plurality of layers made of fibers were laminated. When the fibrillation property was evaluated, this fiber sheet was separated into a plurality of layers due to delamination between the layers. When cells are cultured using this fiber sheet, it is expected that delamination will occur between the layers in the culture medium. It can be said that a fiber sheet that causes delamination in a culture solution is not suitable as a scaffold material for producing cultivated meat.

The fiber structure of this embodiment is suitable as a scaffolding material for producing cultured meat. The fiber structure of the present embodiment can also be used for applications other than scaffolding materials for cultured meat, such as foods other than cultured meat, chemical products, and medicines.

Claims (20)

A fibrous structure comprising fibers,
A fibrous structure having a porous structure and an apparent density of 0.04 g/cm ³ or less. The fiber structure according to claim 1, which is in the form of a sheet. The fiber structure according to claim 2, which has a single layer structure. The fiber structure according to claim 2, which has a thickness of 3 mm or more. The fiber structure according to claim 1, wherein the fibers have an average fiber diameter of 1 μm or more. The fiber structure according to claim 1, wherein the fibers are oriented. The fiber structure according to claim 1, wherein a graph prepared by the following test method has a first peak and a second peak different from the first peak.
Test method: Observe the surface of the fiber structure with a scanning electron microscope. The obtained electron microscope image is binarized to create a binarized image. A power spectrum is obtained by Fourier transforming the binarized image. The angular distribution of the average amplitude is calculated from the power spectrum, and a graph is created in which the horizontal axis is the angle and the vertical axis is the average amplitude. The fiber structure according to claim 7, wherein the difference between the angle θ ₁ corresponding to the apex of the first peak and the angle θ ₂ corresponding to the apex of the second peak is 70° to 130°. The fiber structure according to claim 1, wherein the fibers contain polysaccharides. The fiber structure according to claim 1, wherein the fibers contain alginic acid and/or alginate. The fiber structure according to claim 1, which is edible. The fiber structure according to claim 1, further comprising an adhesion improver that improves cell adhesion and further comprising a coating layer that coats the fibers. The fiber structure according to claim 1, which is used as a substrate for culturing cells. A scaffolding material for cultured meat, comprising the fiber structure according to any one of claims 1 to 13. A method for producing a fiber structure, which includes bringing a structure having gel-like fibers containing water into contact with alcohol. The production method according to claim 15, wherein the alcohol is ethanol. Winding the gel-like fiber around a bobbin to produce a wound body;
cutting the wound body so as to obtain the sheet-like structure;
16. The manufacturing method of claim 15, further comprising: The manufacturing method according to claim 17, wherein the gel-like fibers are wound around the bobbin while being traversed. The manufacturing method according to claim 18, wherein the ratio of the number of traverses per second to the number of revolutions (rps) of the bobbin is 0.25-5. ejecting a solution containing a polysaccharide and water from a nozzle;
contacting the discharge from the nozzle with a coagulating liquid such that the gel-like fibers are formed;
16. The manufacturing method of claim 15, further comprising:

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