JP2021003099A - Resin fiber for cell adhesion and cell adhesion structure - Google Patents

Abstract

To provide resin fibers for cell adhesion by which a cell adhesion structure with excellent shape-retaining property can be obtained.SOLUTION: Resin fibers for cell adhesion are used for adhering cells, and contain resin having a polyvinyl acetal skeleton or a poly(meth)acrylic acid ester skeleton.SELECTED DRAWING: Figure 1

Description

The present invention relates to a resin fiber for cell adhesion used for adhering cells. The present invention also relates to a cell adhesion structure using the above-mentioned resin fiber for cell adhesion.

Animal cells such as humans, mice, rats, pigs, cows and monkeys are used in research and development in academic fields, drug discovery fields, regenerative medicine fields and the like. Conventionally, as a method for transporting animal cells, a method of freezing and transporting animal cells and a liquid medium using a cryoprotectant such as dimethyl sulfoxide, and a method of transporting the animal cells in the liquid medium without freezing have been performed. ing.

Further, as a method for transporting animal cells, a method of producing cell fibers (cell adhesion structures) from animal cells and transporting the cells in the state of the cell fibers is known. The cell fiber includes a core portion and a shell portion arranged on the outer surface of the core portion. The core portion contains a matrigel containing laminin, collagen and the like, and cells arranged on the surface of the matrigel. The shell portion is formed of hydrogel. The cell fiber is disclosed in, for example, Patent Document 1 below.

Japanese Unexamined Patent Publication No. 2018-078917

In the method of freezing and transporting animal cells and liquid medium, cells may die during freezing or thawing. In addition, in the method of transporting animal cells in a liquid medium, stress is applied to the cells due to vibration during transportation or the like. For this reason, these transport methods may reduce cell viability.

On the other hand, in the method of transporting using a cell adhesion structure (cell fiber), the cells can be transported without freezing the cells and without excessively stressing the cells, so that the survival rate of the cells can be improved. Can be kept high. However, in the conventional cell adhesion structure containing Matrigel, the morphological retention of the cell adhesion structure may be low. For example, in a conventional cell adhesion structure containing Matrigel, the morphology tends to collapse within 24 hours after the cell adhesion structure is produced.

An object of the present invention is to provide a cell adhesion resin fiber capable of obtaining a cell adhesion structure having excellent morphological retention. Another object of the present invention is to provide a cell adhesion structure using the above-mentioned resin fiber for cell adhesion.

According to a broad aspect of the present invention, it is a resin fiber for cell adhesion used for adhering cells, and the resin fiber for cell adhesion includes a resin having a polyvinyl acetal skeleton or a poly (meth) acrylic acid ester skeleton. A resin fiber for cell adhesion, which is a resin fiber, is provided.

In a specific aspect of the cell adhesion resin fiber according to the present invention, the dispersion component γ ^d of the surface free energy of the resin film formed by using the material of the cell adhesion resin fiber is 24.5 mJ / m ² or more. It is less than 45.0 mJ / m ² , and the dipole component γ ^p of the surface free energy is 1.0 mJ / m ² or more and less than 20.0 mJ / m ² .

In another specific aspect of the cell adhesion resin fiber according to the present invention, the cell adhesion resin fiber is a resin fiber of a resin having a polyvinyl acetal skeleton.

In still another specific aspect of the cell adhesion resin fiber according to the present invention, the cell adhesion resin fiber has a phase-separated structure.

In yet another specific aspect of the resin fiber for cell adhesion according to the present invention, the resin having a polyvinyl acetal skeleton or a poly (meth) acrylic acid ester skeleton has a main chain having a polyvinyl acetal skeleton and poly (meth) acrylic. It has a graft chain having an acid ester skeleton.

In still another specific aspect of the cell adhesion resin fiber according to the present invention, the ratio of the content of hydrophilic functional groups to the content of hydrophobic functional groups is 0.1 or more and 1.5 or less.

In yet another specific aspect of the resin fiber for cell adhesion according to the present invention, in the resin having the polyvinyl acetal skeleton or the poly (meth) acrylic acid ester skeleton, the hydrophilic functional group with respect to the content of the hydrophobic functional group. The content ratio is 0.1 or more and 1.5 or less.

In still another specific aspect of the resin fiber for cell adhesion according to the present invention, the resin having a polyvinyl acetal skeleton or a poly (meth) acrylic acid ester skeleton has a hydrophilic structural unit and a hydrophobic structural unit. The ratio of the content of the hydrophilic structural unit to the content of the hydrophobic structural unit is 0.1 or more and 1.5 or less.

In still another specific aspect of the resin fiber for cell adhesion according to the present invention, the average fiber diameter is 100 nm or more and 10 μm or less.

According to a broad aspect of the present invention, the core portion includes a core portion and a shell portion arranged on the outer surface of the core portion, and the core portion includes the above-mentioned cell adhesion resin fiber and the cell adhesion resin fiber. Provided is a cell adhesion structure comprising cells adhered onto the surface of the cell and the shell portion comprising hydrogel.

The cell adhesion resin fiber according to the present invention is a cell adhesion resin fiber used for adhering cells, and the cell adhesion resin fiber has a polyvinyl acetal skeleton or a poly (meth) acrylic acid ester skeleton. Since it is a resin fiber containing, a cell adhesion structure having excellent morphological retention can be obtained.

FIG. 1 is a cross-sectional view schematically showing a cell adhesion structure according to an embodiment of the present invention. FIG. 2 is a diagram for explaining a method for producing a cell adhesion structure according to an embodiment of the present invention.

The details of the present invention will be described below.

The resin fiber for cell adhesion according to the present invention is used for adhering cells. The cell adhesion resin fiber according to the present invention is used for adhering cells to the surface of the cell adhesion resin fiber. The resin fiber for cell adhesion according to the present invention is a resin fiber containing a resin having a polyvinyl acetal skeleton or a poly (meth) acrylic acid ester skeleton.

In the present specification, "resin fiber for cell adhesion" may be abbreviated as "resin fiber". Further, in the present specification, "a resin having a polyvinyl acetal skeleton or a poly (meth) acrylic acid ester skeleton" may be referred to as "resin X".

Therefore, the resin fiber according to the present invention is a resin fiber containing resin X. The resin fiber is made of a resin containing resin X.

Since the resin fiber according to the present invention has the above-mentioned structure, a cell adhesion structure having excellent morphological retention can be obtained. Further, since the resin fiber according to the present invention has the above-mentioned structure, the cell adhesion can be enhanced in the obtained cell adhesion structure. Therefore, by using the cell adhesion structure containing the resin fiber according to the present invention, the survival rate of the cells can be enhanced, and the cells can be transported to a destination at a long distance. Further, since the resin fiber according to the present invention contains a synthetic resin, it is cheaper than conventional fibers such as Matrigel, which is a natural polymer material, has small variation between lots, and is excellent in safety.

From the viewpoint of further enhancing the morphological retention of the cell adhesion structure, the dispersion component γ ^d of the surface free energy of the resin film formed by using the above resin fiber material is 24.5 mJ / m ² or more and 45.0 mJ /. less than m ^2, the dipole component gamma ^p of the surface free energy is preferably less than 1.0 mJ / ^{m 2} or more 20.0mJ / ^{m 2.}

From further enhance the viewpoint than the shape retention yet of cell adhesion structures, variance components gamma ^d of the surface free energy of the resin film is preferably 28.0mJ / ^{m 2} or more, 32.8mJ / ^{m 2} or more more preferably, it is preferably 38.0mJ / ^{m 2} or less, and more preferably 36.0mJ / ^{m 2} or less.

From further enhance the viewpoint than the shape retention yet of cell adhesion structures, dipole component gamma ^p of the surface free energy of the resin film is preferably 1.5 mJ / ^{m 2} or more, 2.5 mJ / ^{m 2} The above is more preferable, 10.0 mJ / m ² or less is preferable, and 5.0 mJ / m ² or less is more preferable.

The dispersion component γ ^d of the surface free energy and the dipole component γ ^p are calculated using the theoretical formula of Kaelble-Uy. The Kaelble-Uy theoretical formula is a theoretical formula based on the assumption that the total surface free energy γ is the sum of the dispersion component γ ^d and the dipole component γ ^p , as shown by the following formula (1).

In the Kaelble-Uy theoretical formula, the surface free energy of the liquid is γ _l (mJ / m ² ), the surface free energy of the solid is γ _s (mJ / m ² ), and the contact angle is θ (°). Then, the following equation (2) is established.

Therefore, using two types of liquids whose surface free energy γ _l is known, the contact angles θ with respect to the resin film formed by using the resin fiber material are measured, and the contact angles θ of γ _s ^d and γ _s ^p are measured. By solving the simultaneous equations, the dispersion component γ ^d and the dipole component γ ^p of the surface free energy of the resin fiber can be obtained.

In the present invention, pure water and diiodomethane are used as the two types of liquids whose surface free energy γ _l is known.

The contact angle θ is measured as follows using a contact angle meter (for example, “DMo-701” manufactured by Kyowa Interface Science Co., Ltd.).

1 μL of pure water or diiodomethane is added dropwise to the surface of the resin film formed by using the resin fiber material. The angle formed by the pure water 30 seconds after the dropping and the resin film is defined as the contact angle θ with respect to the pure water. Similarly, the angle formed by the diiodomethane 30 seconds after the dropping and the resin film is defined as the contact angle θ with respect to the diiodomethane.

The resin film can be obtained by molding the same material as the resin fiber into a film shape, or by heating the resin fiber or the like to process it into a film shape.

Since the resin X is used in the resin fiber according to the present invention, the dispersion component γ ^d of the surface free energy and the dipole component γ ^p can be easily controlled within the above preferable ranges. Further, the surface free energy is dispersed by increasing the content of the hydrophobic functional group in the resin X, increasing the content of the functional group having a cyclic structure, and decreasing the content of the alkyl group. The component γ ^d can be reduced. Further, by increasing the content of the hydrophilic functional group in the resin X or increasing the content of the alkyl group, the dipole component γ ^p of the surface free energy can be reduced.

From the viewpoint of further enhancing the adhesiveness of cells, the resin fibers preferably have a phase-separated structure. The phase-separated structure has at least a first layer and a second layer.

Examples of the phase-separated structure include microphase-separated structures such as a sea-island structure, a cylinder structure, a gyroid structure, and a lamellar structure. In the sea-island structure, for example, the first phase can be the sea part and the second phase can be the island part. In a cylinder structure, a gyroid structure, or a lamellar structure, for example, the phase having the largest surface area can be the first phase, and the phase having the second largest surface area can be the second phase. Among these, the sea-island structure is preferable as the phase-separated structure. As described above, by having the continuous phase and the discontinuous phase, the affinity with the cell can be enhanced and the adhesiveness of the cell can be further enhanced.

When the phase-separated structure is a sea-island structure, the surface integration ratio of the island portion (second layer) with respect to the entire surface of the resin fiber is preferably 0.01 or more, more preferably 0.1 or more, still more preferable. Is 0.2 or more, preferably 0.95 or less, more preferably 0.9 or less, still more preferably 0.8 or less. When the surface integration ratio is equal to or higher than the lower limit and lower than the upper limit, the adhesiveness of cells can be further enhanced.

The presence or absence of the phase-separated structure can be confirmed by, for example, an atomic force microscope (AFM), a transmission electron microscope (TEM), a scanning electron microscope (SEM), or the like. Further, the surface area integration factor can be obtained from a microscope observation image using image analysis software such as ImageJ.

The phase-separated structure is formed, for example, by blending, copolymerizing, or graft-copolymerizing at least two kinds of polymers to form a phase-separated structure between or within the molecules of the resin X. be able to. From the viewpoint of further enhancing the adhesiveness of cells, it is preferable that the phase separation structure is formed by the intramolecular phase separation structure of the resin X. That is, the resin X is preferably a copolymer of at least two different polymers, and more preferably a graft copolymer.

The phase-separated structure is preferably formed by copolymerizing two or more kinds of polymers (monomers) having a solubility parameter (SP value) of 0.1 or more, preferably 0.5 or more, more preferably 1 or more. Can be done. In this case, the sea-island structure can be formed more easily.

The SP value is a measure of the intermolecular force acting between a solvent and a solute, and is a measure of the affinity between substances. The SP value can be determined based on Hidebrand's theory of regular solutions. Further, the SP value can be obtained from literature information, a calculation method of Hansen or Hoy, an estimation method of Fedors, or the like. In the present specification, it means a calculated value calculated by the formula δ ² = ΣE / ΣV of Fedors (δ is an SP value, E is an evaporation energy, and V is a molar volume). The unit of the SP value is (cal / cm ³ ) ^0.5 . The Fedors method is described in the Journal of the Japan Adhesive Society, Vol. 22, 1986, p. 566.

In the phase separation structure, another phase different from the first phase and the second phase may exist. The other phase may be one phase or a plurality of phases. Such a phase can be obtained, for example, by copolymerizing another polymer (monomer) having a different SP value by grafting or the like. In this case, the two phases occupying the surface of the resin material with a large area are referred to as the first phase and the second phase.

The resin fiber and the material of the resin fiber include resin X. The resin fiber and the material of the resin fiber may contain a polymer such as a resin different from the resin X.

The content of the resin X in 100% by weight of the resin fiber is preferably 90% by weight or more, more preferably 95% by weight or more, still more preferably 97.5% by weight or more, and particularly preferably 99% by weight or more. Is 100% by weight (total amount). Therefore, the resin fiber is most preferably a resin fiber of resin X. Most preferably, the resin fiber is a fibrous resin X. Most preferably, the material of the resin fiber is resin X. When the content of the resin X is at least the above lower limit, the morphological retention of the cell adhesion structure can be further enhanced, and the cell adhesion can be further enhanced. Further, the dispersion component γ ^d of the surface free energy and the dipole component γ ^p can be easily controlled within the above preferable ranges.

The resin fiber (component constituting the resin fiber) has a hydrophilic functional group and a hydrophobic functional group. Resin X has a hydrophobic functional group and a hydrophilic functional group.

Examples of the hydrophilic functional group include a hydroxyl group, an amino group, an amide group, an imino group, a thiol group, a carboxyl group, a sulfonyl group, an ether group, a thioether group, and a polyether group.

Examples of the hydrophobic functional group include an acetal group, an alkyl group, a phenyl group, an acetyl group and the like.

In the above resin fiber, the ratio of the content of hydrophilic functional groups to the content of hydrophobic functional groups (content of hydrophilic functional groups / content of hydrophobic functional groups) is preferably 0.1 or more. It is preferably 0.2 or more, preferably 10.0 or less, more preferably 5.0 or less, still more preferably 1.5 or less, and particularly preferably 1.0 or less. When the above ratio (content of hydrophilic functional group / content of hydrophobic functional group) is at least the above lower limit and at least the above upper limit, the morphological retention of the cell adhesion structure can be further enhanced, and the cells can be further enhanced. The adhesiveness of the product can be further improved. When the ratio (content of hydrophilic functional group / content of hydrophobic functional group) is equal to or higher than the lower limit and lower than the upper limit, the dispersion component γ ^d of the surface free energy and the dipole component γ ^p are added. It can be easily controlled within the preferable range of.

The content of the hydrophobic functional group and the content of the hydrophilic functional group in the resin fiber are the total of the content of the hydrophobic functional group and the hydrophilic functional group of all the components contained in the resin fiber as 100 mol%. It means the content of hydrophobic functional groups and the content of hydrophilic functional groups when Therefore, when the resin fiber contains only the resin X, the content of the hydrophobic functional group and the content of the hydrophilic functional group in the resin fiber are the content of the hydrophobic functional group and the hydrophilic functional group of the resin X. Means the content rate of. Further, when the resin fiber contains a component different from the resin X and the resin X, the content of the hydrophobic functional group and the content of the hydrophilic functional group in the resin fiber are different from those of the resin X and the resin X. It means the content of the hydrophobic functional group and the content of the hydrophilic functional group when the total content of the hydrophobic functional group and the hydrophilic functional group of the whole is 100 mol%.

In the resin X, the ratio of the content of the hydrophilic functional group to the content of the hydrophobic functional group (content of the hydrophilic functional group / content of the hydrophobic functional group) is preferably 0.1 or more, more preferably 0.1 or more. Is 0.2 or more, preferably 10.0 or less, more preferably 5.0 or less, still more preferably 1.5 or less, and particularly preferably 1.0 or less. When the above ratio (content of hydrophilic functional group / content of hydrophobic functional group) is at least the above lower limit and at least the above upper limit, the morphological retention of the cell adhesion structure can be further enhanced, and the cells can be further enhanced. The adhesiveness of the product can be further improved. When the ratio (content of hydrophilic functional group / content of hydrophobic functional group) is equal to or higher than the lower limit and lower than the upper limit, the dispersion component γ ^d of the surface free energy and the dipole component γ ^p are added. It can be easily controlled within the preferable range of.

From the viewpoint of further enhancing the morphological retention of the cell adhesion structure, the content of the hydrophobic functional group in the resin fiber and the resin X is preferably 40 mol% or more, more preferably 50 mol% or more. It is more preferably 60 mol% or more, preferably 95 mol% or less, more preferably 90 mol% or less, still more preferably 85 mol% or less.

From the viewpoint of further enhancing the morphological retention of the cell adhesion structure, the content of the hydrophilic functional group in the resin fiber and the resin X is preferably 5 mol% or more, more preferably 10 mol% or more. It is more preferably 15 mol% or more, preferably 60 mol% or less, more preferably 50 mol% or less, still more preferably 40 mol% or less.

The resin X preferably has a hydrophilic structural unit and a hydrophobic structural unit. The hydrophilic structural unit means a structural unit having a hydrophilic functional group. The hydrophobic structural unit is a structural unit different from the hydrophilic structural unit, and means a structural unit having a hydrophobic functional group.

When the resin fiber contains a component other than the resin X, the component other than the resin X is preferably a polymer having the above hydrophilic structural unit and the hydrophobic structural unit.

In the resin X, the ratio of the content of the hydrophilic structural unit to the content of the hydrophobic structural unit (content of the hydrophilic structural unit / content of the hydrophobic structural unit) is preferably 0.1 or more. It is more preferably 0.2 or more, preferably 10.0 or less, more preferably 5.0 or less, still more preferably 1.5 or less, and particularly preferably 1.0 or less. When the above ratio (content rate of hydrophilic structural unit / content rate of hydrophobic structural unit) is at least the above lower limit and at least the above upper limit, the morphological retention of the cell adhesion structure can be further enhanced, and the cells The adhesiveness of the product can be further enhanced. The total of the content of the hydrophobic structural unit and the content of the hydrophilic structural unit is 100 mol% (the total structural unit of the resin X).

When the resin fiber contains a polymer other than resin X, the ratio of the content of the hydrophilic structural unit to the content of the hydrophobic structural unit in the polymer (content of hydrophilic structural unit / hydrophobic structural unit). Content rate) is preferably 0.1 or more, more preferably 0.2 or more. In the polymer, the ratio of the content of the hydrophilic structural unit to the content of the hydrophobic structural unit (content of the hydrophilic structural unit / content of the hydrophobic structural unit) is preferably 10.0 or less. It is more preferably 5.0 or less, further preferably 1.5 or less, and particularly preferably 1.0 or less. When the above ratio (content rate of hydrophilic structural unit / content rate of hydrophobic structural unit) is at least the above lower limit and at least the above upper limit, the morphological retention of the cell adhesion structure can be further enhanced, and the cells The adhesiveness of the product can be further enhanced. The total of the content of the hydrophobic structural unit and the content of the hydrophilic structural unit is 100 mol% (total structural unit of the polymer).

From the viewpoint of further enhancing the morphological retention of the cell adhesion structure, the content of the hydrophobic structural unit in each of the resin X and the polymer other than the resin X is preferably 40 mol% or more, more preferably 50. It is mol% or more, more preferably 60 mol% or more, preferably 95 mol% or less, more preferably 90 mol% or less, still more preferably 85 mol% or less.

From the viewpoint of further enhancing the morphological retention of the cell adhesion structure, the content of the hydrophilic structural unit in each of the resin X and the polymer other than the resin X is preferably 5 mol% or more, more preferably 10. It is mol% or more, more preferably 15 mol% or more, preferably 60 mol% or less, more preferably 50 mol% or less, still more preferably 40 mol% or less.

In the resin X, the total content of the structural units having an acetal group, an alkyl group, a phenyl group or an acetyl group is defined as the content rate A. In the resin X, the total content of the structural units having a hydroxyl group, an amino group, an amide group, an imino group, a thiol group, a carboxyl group, a sulfonyl group, an ether group, a thioether group and a polyether group is defined as the content rate B.

The ratio of the content rate B to the content rate A (content rate B / content rate A) is preferably 0.1 or more, more preferably 0.2 or more, preferably 10.0 or less, and more preferably 5. It is 0 or less, more preferably 1.5 or less, and particularly preferably 1.0 or less. When the ratio (content rate B / content rate A) is at least the above lower limit and at least the above upper limit, the morphological retention of the cell adhesion structure can be further enhanced, and the cell adhesion can be further enhanced. Can be done.

From the viewpoint of further enhancing the morphological retention of the cell adhesion structure, the content A is preferably 40 mol% or more, more preferably 50 mol% or more, still more preferably 60 mol% or more, preferably 95 mol% or less. , More preferably 90 mol% or less, still more preferably 85 mol% or less.

From the viewpoint of further enhancing the morphological retention of the cell adhesion structure, the content B is preferably 5 mol% or more, more preferably 10 mol% or more, still more preferably 15 mol% or more, preferably 60 mol% or less. , More preferably 50 mol% or less, still more preferably 40 mol% or less.

When the resin fiber contains a polymer other than the resin X, the total content of the structural units having an acetal group, an alkyl group, a phenyl group or an acetyl group in the polymer is defined as the content rate C. When the resin fiber contains a polymer other than resin X, the structural unit having a hydroxyl group, an amino group, an amide group, an imino group, a thiol group, a carboxyl group, a sulfonyl group, an ether group, a thioether group, and a polyether group in the polymer. Let the total content of the above be the content rate D.

The ratio of the content rate D to the content rate C (content rate D / content rate C) is preferably 0.1 or more, more preferably 0.2 or more, preferably 10.0 or less, and more preferably 5. It is 0 or less, more preferably 1.5 or less, and particularly preferably 1.0 or less. When the ratio (content rate D / content rate C) is at least the above lower limit and at least the above upper limit, the morphological retention of the cell adhesion structure can be further enhanced, and the cell adhesion can be further enhanced. Can be done.

From the viewpoint of further enhancing the morphological retention of the cell adhesion structure, the content C is preferably 40 mol% or more, more preferably 50 mol% or more, still more preferably 60 mol% or more, preferably 95 mol% or less. , More preferably 90 mol% or less, still more preferably 85 mol% or less.

From the viewpoint of further enhancing the morphological retention of the cell adhesion structure, the content D is preferably 5 mol% or more, more preferably 10 mol% or more, still more preferably 15 mol% or more, preferably 60 mol% or less. , More preferably 50 mol% or less, still more preferably 40 mol% or less.

The content of the hydrophobic functional group, the content of the hydrophilic functional group, the content of the hydrophobic structural unit, the content of the hydrophilic structural unit, the content A, the content B, the content C , The above-mentioned content rate D can be measured by ¹ H-NMR (nuclear magnetic resonance spectrum).

Hereinafter, the resin constituting the resin fiber will be described in more detail.

(Resin in resin fiber)
Resin X:
The resin constituting the resin fiber contains a resin (resin X) having a polyvinyl acetal skeleton or a poly (meth) acrylic acid ester skeleton. The resin X may be a composite resin.

The resin X may be a resin having a polyvinyl acetal skeleton, a resin having a poly (meth) acrylic acid ester skeleton, and having both a polyvinyl acetal skeleton and a poly (meth) acrylic acid ester skeleton. It may be a resin. As the resin X, only one type may be used, or two or more types may be used in combination.

From the viewpoint of further enhancing the morphological retention of the cell adhesion structure and further enhancing the cell adhesion, the resin X is a resin having a polyvinyl acetal skeleton, or a polyvinyl acetal skeleton and poly (meth) acrylic. A resin having an acid ester skeleton is preferable. The resin X is preferably a resin having at least a polyvinyl acetal skeleton. The resin fiber is preferably a resin fiber of a resin having a polyvinyl acetal skeleton, and is also preferably a resin fiber of a resin having a polyvinyl acetal skeleton and a polyvinyl acetal skeleton.

<Resin having a polyvinyl acetal skeleton>
The cell adhesion resin fiber preferably contains a resin having a polyvinyl acetal skeleton as the resin X. The resin X is preferably a polyvinyl acetal resin. The polyvinyl acetal resin is a resin having a polyvinyl acetal skeleton. The polyvinyl acetal resin can be synthesized by acetalizing polyvinyl alcohol with an aldehyde. The polyvinyl acetal resin has an acetal group, an acetyl group, and a hydroxyl group in the side chain.

The aldehyde used for acetalizing polyvinyl alcohol is not particularly limited. Examples of the aldehyde include aldehydes having 1 to 10 carbon atoms. The aldehyde may have a chain aliphatic group, a cyclic aliphatic group or an aromatic group. The aldehyde may be a chain aldehyde or a cyclic aldehyde.

Examples of the above aldehydes include formaldehyde, acetaldehyde, propionaldehyde, butylaldehyde, pentanal, hexanal, heptanal, octanal, nonanal, decanal, achlorine, benzaldehyde, cinnamaldehyde, perylaldehyde, formylpyridine, formylimidazole, formylpyrrole, formylpiperidin, formyl. Triazole, formyltetrazole, formylindole, formylisoindole, formylpurine, formylbenzoimidazole, formylbenzotriazole, formylquinoline, formylisoquinolin, formylquinoxalin, formylcinnoline, formylpteridine, formylfuran, formyloxolane, formyloxane, Examples thereof include formylthiophene, formylthiolan, formyltian, formyladenine, formylguanine, formylcitosine, formyltimine, and formyluracil. Only one kind of the above aldehyde may be used, or two or more kinds may be used in combination.

The aldehyde is preferably formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, or pentanal, and more preferably butyraldehyde. Therefore, the polyvinyl acetal skeleton is preferably a polyvinyl butyral skeleton. The resin X is preferably a polyvinyl butyral resin.

The blending amount of the aldehyde can be appropriately set according to the target amount of acetal groups. From the viewpoint of increasing the efficiency of the acetalization reaction and easily removing the unreacted aldehyde, the amount of the aldehyde added is preferably 60 mol% or more, more preferably 65 mol% with respect to 100 mol% of polyvinyl alcohol. % Or more, preferably 95 mol% or less, more preferably 90 mol% or less.

The average degree of polymerization of the polyvinyl acetal resin is preferably 100 or more, more preferably 200 or more, further preferably 500 or more, particularly preferably 1500 or more, preferably 6000 or less, more preferably 3000 or less, still more preferably 2500 or less. is there. When the average degree of polymerization is at least the above lower limit, the strength of the resin fiber can be increased. When the average degree of polymerization is not more than the above upper limit, the handleability can be improved and the moldability of the resin fiber can be improved.

The number average molecular weight (Mn) of the polyvinyl acetal resin is preferably 10,000 or more, preferably 600,000 or less. The weight average molecular weight (Mw) of the polyvinyl acetal resin is preferably 2000 or more, preferably 1200,000 or less. Further, in the polyvinyl acetal resin, the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 2.0 or more, preferably 40 or less. When the Mn, the Mw, and the Mw / Mn are equal to or higher than the lower limit and lower than the upper limit, the strength of the resin fiber can be increased.

The degree of acetalization of the polyvinyl acetal resin (degree of butyralization in the case of polyvinyl butyral resin) is preferably 60 mol% or more, more preferably 65 mol% or more, preferably 90 mol% or less, more preferably 85 mol%. It is as follows. When the degree of acetalization is at least the above lower limit, the adhesiveness of cells can be further enhanced. When the degree of acetalization is not more than the above upper limit, the solubility in a solvent can be improved.

The degree of acetylation (acetyl group amount) of the polyvinyl acetal resin is preferably 0.0001 mol% or more, preferably 5 mol% or less.

The hydroxyl group content (hydroxyl group amount) of the polyvinyl acetal resin is preferably 5 mol% or more, more preferably 10 mol% or more, preferably 60 mol% or less, and more preferably 50 mol% or less.

The degree of acetalization, the degree of acetylation, and the amount of hydroxyl groups of the polyvinyl acetal resin can be measured by ¹ H-NMR (nuclear magnetic resonance spectrum).

The polyvinyl acetal resin may be copolymerized with a vinyl compound. The polyvinyl acetal resin may be a copolymer with a vinyl compound. In the present invention, the polyvinyl acetal resin copolymerized with the vinyl group is also regarded as the polyvinyl acetal resin. The vinyl compound is a compound having a vinyl group (H ₂ C = CH−). The vinyl compound may be a polymer having a structural unit having a vinyl group.

The copolymer may be a block copolymer of a polyvinyl acetal resin and a vinyl compound, or may be a graft copolymer obtained by grafting a vinyl compound on the polyvinyl acetal resin. The copolymer is preferably a graft copolymer.

The copolymer can be synthesized, for example, by the following methods (1) to (3). (1) A method for synthesizing a polyvinyl acetal resin using polyvinyl alcohol in which a vinyl compound is copolymerized. (2) A method for synthesizing a polyvinyl acetal resin using polyvinyl alcohol and polyvinyl alcohol in which a vinyl compound is copolymerized. (3) A method of graft-copolymerizing a vinyl compound with a polyvinyl acetal resin before graft copolymerization.

Examples of the vinyl compound include ethylene, allylamine, vinylpyrrolidone, maleic anhydride, maleimide, itaconic acid, (meth) acrylic acid, vinylamine, and (meth) acrylic acid ester. Only one kind of the vinyl compound may be used, or two or more kinds thereof may be used in combination. The copolymer of the polyvinyl acetal resin and the (meth) acrylic acid ester will be described later.

From the viewpoint of further enhancing the adhesiveness of cells, the polyvinyl acetal resin preferably has a Bronsted basic group or a Bronsted acidic group, and more preferably has a Bronsted basic group. That is, it is preferable that a part of the polyvinyl acetal resin is modified with a Bronsted basic group or a Bronsted acidic group, and more preferably a part of the polyvinyl acetal resin is modified with a Bronsted basic group.

The Bronsted basic group is a general term for functional groups capable of receiving hydrogen ion H ⁺ from other substances. Examples of the blended basic group include amine-based basic groups such as a substituent having an imine structure, a substituent having an imide structure, a substituent having an amine structure, and a substituent having an amide structure.

The polyvinyl acetal resin preferably has a structural unit having an imine structure, a structural unit having an imide structure, a structural unit having an amine structure, or a structural unit having an amide structure. In this case, it may have only one of these structural units, or it may have two or more.

The polyvinyl acetal resin preferably has a structural unit having an imine structure. The imine structure refers to a structure having a C = N bond. The polyvinyl acetal resin preferably has an imine structure in the side chain. In this case, the imine structure may be directly bonded to the carbon atom constituting the main chain of the polyvinyl acetal resin, or may be bonded to the main chain via a linking group such as an alkylene group. In addition, having the above-mentioned imine structure in the side chain also includes having the above-mentioned imine structure in the graft chain of the polyvinyl acetal resin. Examples of the structural unit having the imine structure include the structural unit represented by the following formula (11) or the following formula (12).

In the above formula (11), R ₁ represents a group having an imine structure.

In the above formula (12), R ₁ represents a group having an imine structure, and R ₂ represents an alkylene group. The alkylene group has preferably 1 or more carbon atoms, preferably 12 or less carbon atoms, and more preferably 5 or less carbon atoms. When the carbon number of the alkylene group is at least the above lower limit and at least the above upper limit, the strength of the resin fiber can be increased.

Examples of the alkylene group include linear alkylene groups such as methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, octamethylene group and decamethylene group, methylmethylene group and methylethylene group, 1 Examples thereof include a branched alkylene group such as a methylpentylene group and a 1,4-dimethylbutylene group, a cyclic alkylene group such as a cyclopropylene group, a cyclobutylene group and a cyclohexylene group. The alkylene group is preferably a linear alkyl group such as a methylene group, an ethylene group, a trimethylene group, or a tetramethylene group, and more preferably a methylene group or an ethylene group.

The _{R 1} in the above formula (11) _{R 1} and the formula in (12), include groups represented by the following formula (13).

In the above formula (13), R ₃ represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, and R ₄ represents a hydrocarbon group having 1 to 18 carbon atoms.

Examples of the hydrocarbon group include saturated hydrocarbon groups, unsaturated hydrocarbon groups, aromatic hydrocarbon groups and the like. The hydrocarbon group may consist of only one of a saturated hydrocarbon group, an unsaturated hydrocarbon group, and an aromatic hydrocarbon group, and two or more of these are used. You may.

Examples of the saturated hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, pentyl group and hexyl group. Examples thereof include a petit group, a 2-ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group and an octadecyl group. The saturated hydrocarbon group is preferably a methyl group, an ethyl group, an n-propyl group, or an n-butyl group.

Examples of the aromatic hydrocarbon group include a phenyl group, a toluyl group, a xsilyl group, a t-butylphenyl group, a benzyl group and the like.

The structural unit having the imine structure has a structure represented by the above formula (11), and in the above formula (13), R ₃ is a hydrogen atom, a methyl group, or an ethyl group, and R ₄ is methyl. It is preferably a structural unit which is a group, an ethyl group or a propyl group.

In the polyvinyl acetal resin, the content of the structural unit having the imine structure is preferably 0.1 mol% or more, more preferably 1.0 mol% or more, preferably 20.0 mol% or less, more preferably 15. It is 0.0 mol% or less. When the content is at least the above lower limit and at least the above upper limit, the adhesiveness of cells can be further enhanced.

In the polyvinyl acetal resin, the ratio of the content of structural units having an imine structure to the degree of acetalization (content of structural units having an imine structure / degree of acetalization) is preferably 0.001 or more, preferably 0. It is less than 5.5. When the above ratio (content rate of structural unit having an imine structure / degree of acetalization) is at least the above lower limit and at least the above upper limit, the strength of the resin fiber can be increased and the adhesiveness of the cells can be enhanced. ..

The polyvinyl acetal resin preferably has a structural unit having an imide structure. The structural unit having an imide structure is preferably a structural unit having an imino group (= NH).

The polyvinyl acetal resin preferably has the imino group in the side chain. In this case, the imino group may be directly bonded to the carbon atom constituting the main chain of the polyvinyl acetal resin, or may be bonded to the main chain via a linking group such as an alkylene group.

The polyvinyl acetal resin preferably has a structural unit having an amine structure. The amine group in the above amine structure may be a primary amine group, a secondary amine group, a tertiary amine group, or a quaternary amine group. Good.

The structural unit having an amine structure may be a structural unit having an amide structure. The amide structure refers to a structure having -C (= O) -NH-.

The polyvinyl acetal resin preferably has the amine structure or the amide structure in the side chain. In this case, the amine structure or the amide structure may be directly bonded to the carbon atom constituting the main chain of the polyvinyl acetal resin, or may be bonded to the main chain via a linking group such as an alkylene group. ..

The fact that the amine structure or the amide structure is present in the side chain also includes having the amine structure or the amide structure in the graft chain of the polyvinyl acetal resin.

From the viewpoint of enhancing cell adhesion, the amine group in the amine structure is preferably a primary amine group (-NH ₂ ).

The structural unit having the amine structure is preferably the structure represented by the following formula (21).

The structural unit having the amide structure is preferably the structure represented by the following formula (31).

In the above formula (31), R ₁ represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group and the like.

In the polyvinyl acetal resin, the content of the structural unit having the amine structure or the amide structure is preferably 0.1 mol% or more, more preferably 0.5 mol% or more, preferably 20 mol% or less, respectively. It is preferably 10 mol% or less. When the content is at least the above lower limit, the additional characteristics can be enhanced. When the content is not more than the above upper limit, the polyvinyl acetal resin powder can be easily separated by the precipitation method.

In the polyvinyl acetal resin, the content of the structural unit having an imine structure is preferably 0. In the total of 100 mol% of the content of the structural unit having an imine structure and the content of the structural unit having an amine structure. It is 5 mol% or more, more preferably 5 mol% or more, preferably 99.5 mol% or less, and more preferably 90 mol% or less. In the polyvinyl acetal resin, the content of the structural unit having an imine structure is preferably 100 mol% of the total content of the structural unit having an imine structure and the content of the structural unit having an amide structure. It is 0.5 mol% or more, more preferably 5 mol% or more, preferably 99.5 mol% or less, and more preferably 90 mol% or less. When the content of the structural unit having the imine structure is at least the above lower limit, the viscosity stability over time can be sufficiently sufficient. When the content of the structural unit having the imine structure is not more than the above upper limit, the adhesiveness of the cells can be further enhanced.

In the polyvinyl acetal resin, the total content of the structural unit having the imine structure, the structural unit having the amine structure, and the structural unit having the imide structure is preferably 0.1 mol% or more, more preferably. Is 1 mol% or more, preferably 30 mol% or less, and more preferably 10 mol% or less. Further, in the polyvinyl acetal resin, the total content of the structural unit having the imine structure, the structural unit having the amide structure, and the structural unit having the imide structure is preferably 0.1 mol% or more. It is more preferably 1 mol% or more, preferably 30 mol% or less, and more preferably 10 mol% or less. When the total content is not less than the above lower limit and not more than the above upper limit, the adhesiveness of cells can be further enhanced.

The content of the structural unit having the imine structure, the content of the structural unit having the imide structure, the content of the structural unit having the amine structure, and the content of the structural unit having the amide structure are ¹ H-NMR. It can be measured by (nuclear magnetic resonance spectrum).

The Bronsted acidic group is a general term for functional groups capable of passing hydrogen ions H ⁺ to other substances.

Examples of the blended acidic group include a carboxyl group, a sulfonic acid group, a maleic acid group, a sulfinic acid group, a sulfinic acid group, a phosphoric acid group, a phosphonic acid group, and salts thereof. The Bronsted acidic group is preferably a carboxyl group.

Examples of the method for modifying the polyvinyl acetal resin with the Brensted acidic group include a method of copolymerizing the polyvinyl alcohol with the itaconic acid or (meth) acrylic acid, and a Brensted acidic group on the side chain of the polyvinyl alcohol. There is a method of introducing.

The method for producing a polyvinyl acetal resin having a Bronsted basic group or a Bronsted acidic group is not particularly limited. For example, a polyvinyl acetal resin having a structural unit having an imine structure can be produced, for example, by the following methods (1), (2), (3) or (4). The polyvinyl acetal resin may be an acetal product of polyvinyl alcohol having a structural unit having an amine structure or an amide structure.

(1) Polyvinyl acetate is obtained by copolymerizing the above-mentioned monomer having an imine structure with vinyl acetate. The obtained polyvinyl acetate is saponified to obtain polyvinyl alcohol. The obtained polyvinyl alcohol is acetalized by a conventionally known method.

(2) An imine structure is introduced by acetalizing polyvinyl alcohol having a structural unit having an amine structure or an amide structure by a conventionally known method.

(3) Polyvinyl alcohol having an imine structure obtained by post-denaturing polyvinyl alcohol having a structural unit having an amine structure or an amide structure is acetalized by a conventionally known method.

(4) The imine structure is introduced by modifying the polyvinyl acetal resin.

Of the methods (1) to (4) above, it is particularly preferable to obtain a polyvinyl acetal resin having a structural unit having an imine structure by the method (2).

In the above methods (1) to (4), a polyvinyl acetal resin having a structural unit having an imine structure can be preferably obtained by a method of excessively adding an aldehyde or an acid catalyst used for acetalization.

In the method of adding an excess of aldehyde, it is preferable to add 70 parts by weight to 150 parts by weight of aldehyde with respect to 100 parts by weight of polyvinyl alcohol having a structural unit having an amine structure or an amide structure. In particular, as the aldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-barrel aldehyde, and phenyl aldehyde are preferable.

In the method of adding the acid catalyst in excess, it is preferable to add 0.5% by weight or more of the acid catalyst. Further, it is preferable to add 5.0 parts by weight to 70.0 parts by weight of the acid catalyst with respect to 100 parts by weight of polyvinyl alcohol having a structural unit having an amine structure or an amide structure. In particular, as the acid catalyst, hydrochloric acid, nitric acid, sulfuric acid and p-toluenesulfonic acid are preferable.

A known method can be used for the acetalization. The acetalization is preferably carried out in an aqueous solvent, in a mixed solvent with an organic solvent compatible with water, or in an organic solvent. Examples of the organic solvent compatible with water include alcohol-based organic solvents. Examples of the organic solvent include alcohol-based organic solvents, aromatic organic solvents, aliphatic ester-based solvents, ketone-based solvents, lower paraffin-based solvents, ether-based solvents, amide-based solvents, amine-based solvents and the like. Only one kind of the organic solvent may be used, or two or more kinds may be used in combination.

Examples of the alcohol-based organic solvent include methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol and the like.

Examples of the aromatic organic solvent include xylene, toluene, ethylbenzene, methyl benzoate and the like.

Examples of the aliphatic ester solvent include methyl acetate, ethyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, methyl acetoacetate, ethyl acetoacetate and the like.

Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methylcyclohexanone, benzophenone, acetophenone and the like.

Examples of the lower paraffin solvent include hexane, pentane, octane, cyclohexane, decane and the like.

Examples of the ether solvent include diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol diethyl ether and the like.

Examples of the amide-based solvent include N, N-dimethylformamide, N, N-dimethyltesetoamide, N-methylpyrrolidone, acetanilide and the like.

Examples of the amine-based solvent include ammonia, trimethylamine, triethylamine, n-butylamine, din-butylamine, trin-butylamine, aniline, N-methylaniline, N, N-dimethylaniline, and pyridine.

From the viewpoint of solubility in a resin and simplicity during purification, the organic solvent is preferably ethanol, n-propanol, isopropanol, or tetrahydrofuran.

The acetalization is preferably carried out in the presence of an acid catalyst. The above acid catalyst is not particularly limited, and mineral acids such as sulfuric acid, hydrochloric acid, nitric acid and phosphoric acid, carboxylic acids such as formic acid, acetic acid and propionic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid and paratoluenesulfone are used. Examples thereof include sulfonic acids such as acids. Only one kind of the acid catalyst may be used, or two or more kinds thereof may be used in combination. The acid catalyst is preferably hydrochloric acid, nitric acid or sulfuric acid, and more preferably hydrochloric acid.

<Resin having a poly (meth) acrylic acid ester skeleton>
The cell adhesion resin fiber preferably contains a resin having a poly (meth) acrylic acid ester skeleton as the resin X. The resin X is preferably a poly (meth) acrylic acid ester resin. The poly (meth) acrylic acid ester resin is a resin having a poly (meth) acrylic acid ester skeleton.

The poly (meth) acrylic acid ester resin is obtained by polymerizing a (meth) acrylic acid ester which is a monomer. The poly (meth) acrylic acid ester resin has a skeleton derived from the (meth) acrylic acid ester. The poly (meth) acrylic acid ester resin may be a resin obtained by copolymerizing the (meth) acrylic acid ester with a monomer other than the (meth) acrylic acid ester.

Examples of the (meth) acrylic acid ester include (meth) acrylic acid alkyl ester, (meth) acrylic acid cyclic alkyl ester, (meth) acrylic acid aryl ester, (meth) acrylamide, (meth) acrylic acid polyethylene glycol, and the like. Examples thereof include phosphorylcholine (meth) acrylate.

Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) acrylate. , T-butyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl Examples thereof include (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and isotetradecyl (meth) acrylate.

The (meth) acrylic acid alkyl ester may be substituted with a substituent such as an alkoxy group having 1 to 3 carbon atoms and a tetrahydrofurfuryl group. Examples of such (meth) acrylic acid alkyl esters include methoxyethyl acrylate and tetrahydrofurfuryl acrylate.

Examples of the (meth) acrylic acid cyclic alkyl ester include cyclohexyl (meth) acrylate and isobornyl (meth) acrylate.

Examples of the (meth) acrylic acid aryl ester include phenyl (meth) acrylate and benzyl (meth) acrylate.

Examples of the (meth) acrylamides include (meth) acrylamide, N-isopropyl (meth) acrylamide, N-tert-butyl (meth) acrylamide, N, N'-dimethyl (meth) acrylamide, and (3- (meth) acrylamide). Propyl) trimethylammonium chloride, 4- (meth) acryloylmorpholine, 3- (meth) acryloyl-2-oxazolidinone, N- [3- (dimethylamino) propyl] (meth) acrylamide, N- (2-hydroxyethyl) ( Examples thereof include meta) acrylamide, N-methylol (meth) acrylamide, and 6- (meth) acrylamide hexane acid.

Examples of the (meth) acrylate polyethylene glycols include methoxy-polyethylene glycol (meth) acrylate, ethoxy-polyethylene glycol (meth) acrylate, hydroxy-polyethylene glycol (meth) acrylate, methoxy-diethylene glycol (meth) acrylate, and ethoxy. -Diethylene glycol (meth) acrylate, hydroxy-diethylene glycol (meth) acrylate, methoxy-triethylene glycol (meth) acrylate, ethoxy-triethylene glycol (meth) acrylate, hydroxy-triethylene glycol (meth) acrylate, etc. Can be mentioned.

Examples of the phosphorylcholine (meth) acrylate include 2- (meth) acryloyloxyethyl phosphorylcholine.

Examples of the monomer other than the (meth) acrylic acid ester include (meth) acrylic acid, ethylene, vinyl ester and the like.

In addition, in this specification, "(meth) acrylic" means "acrylic" or "methacryl", and "(meth) acrylate" means "acrylate" or "methacrylate".

From the viewpoint of further enhancing the morphological retention of the cell adhesion structure, the poly (meth) acrylic acid ester resin preferably has a structure derived from the (meth) acrylic acid alkyl ester, and is preferably n-butyl (meth) acrylate. It is more preferable to have a structure derived from methoxyethyl acrylate or lauryl (meth) acrylate.

The number average molecular weight (Mn) of the poly (meth) acrylic acid ester resin is preferably 10,000 or more, preferably 5,000,000 or less. The weight average molecular weight (Mw) of the poly (meth) acrylic acid ester resin is preferably 10,000 or more, preferably 5,000,000 or less.

<Resin having a polyvinyl acetal skeleton and a poly (meth) acrylic acid ester skeleton> The resin fiber for cell adhesion may contain a resin having a polyvinyl acetal skeleton and a poly (meth) acrylic acid ester skeleton as the resin X. preferable. The resin X is preferably a composite resin having a polyvinyl acetal skeleton and a poly (meth) acrylic acid ester skeleton.

The resin having the polyvinyl acetal skeleton and the poly (meth) acrylic acid ester skeleton can be synthesized, for example, by the following methods (1) to (3). (1) A method for synthesizing a polyvinyl acetal resin using polyvinyl alcohol in which an acrylic acid ester is copolymerized. (2) A method for synthesizing a polyvinyl acetal resin using polyvinyl alcohol and polyvinyl alcohol in which an acrylic acid ester is copolymerized. (3) A method of graft-copolymerizing an acrylic acid ester with the above-mentioned polyvinyl acetal resin.

As the acrylic acid ester, the acrylic acid ester described above can be used.

From the viewpoint of further enhancing the morphological retention of the cell adhesion structure and further enhancing the cell adhesion, the resin having a polyvinyl acetal skeleton and a poly (meth) acrylic acid ester skeleton is described in the above-mentioned polyvinyl acetal resin. It is preferable that the (meth) acrylic acid ester is graft-copolymerized with the resin.

From the viewpoint of further enhancing the morphological retention of the cell adhesion structure and further enhancing the cell adhesion, the resin having a polyvinyl acetal skeleton and a poly (meth) acrylic acid ester skeleton is a main chain having a polyvinyl acetal skeleton. And a graft chain having a poly (meth) acrylic acid ester skeleton.

The number average molecular weight (Mn) of the resin having a polyvinyl acetal skeleton and a poly (meth) acrylic acid ester skeleton is preferably 10,000 or more, preferably 600,000 or less. The weight average molecular weight (Mw) of a resin having a polyvinyl acetal skeleton and a poly (meth) acrylic acid ester skeleton is preferably 2000 or more, preferably 1200,000 or less. Further, in a resin having a polyvinyl acetal skeleton and a poly (meth) acrylic acid ester skeleton, the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 2.0 or more, preferably 2.0 or more. Is 40 or less. When the Mn, the Mw, and the Mw / Mn are equal to or higher than the lower limit and lower than the upper limit, the strength of the resin fiber can be increased.

Polymers other than resin X:
The resin fiber may contain a polymer other than the resin X. Examples of the polymer include polyolefin resin, polyether resin, polyvinyl alcohol resin, polyester, epoxy resin, polyamide resin, polyimide resin, polyurethane resin, polycarbonate resin, cellulose, polypeptide and the like.

From the viewpoint of effectively exerting the effect of the present invention, the smaller the content of the polymer other than the resin X, the better. The content of the polymer in 100% by weight of the resin fiber and 100% by weight of the material of the resin fiber is preferably 10% by weight or less, more preferably 5% by weight or less, still more preferably 2.5% by weight or less. It is particularly preferably 1% by weight or less, and most preferably 0% by weight (not contained). Therefore, it is most preferable that the resin fiber does not contain a polymer other than the resin X.

It is preferable that the resin fiber does not substantially contain an animal-derived raw material. By substantially not containing an animal-derived raw material, it is possible to provide a resin fiber having little variation between lots and having excellent cost and safety. In addition, "substantially free of animal-derived raw materials" means that the animal-derived raw materials in the resin fibers are 3% by weight or less. In the resin fiber, the raw material derived from animals in the resin fiber is preferably 1% by weight or less, and more preferably 0% by weight. That is, it is more preferable that the resin fiber does not contain an animal-derived raw material in the resin fiber.

(Other details of resin fibers for cell adhesion)
The resin fiber for cell adhesion according to the present invention is used for adhering cells to the surface of the resin fiber. The resin fiber for cell adhesion according to the present invention is a resin fiber having cell adhesion. In the cell adhesion resin fiber according to the present invention, cells adhered to the surface of the resin fiber may proliferate.

Examples of the cells include animal cells such as humans, mice, rats, pigs, cows and monkeys. Examples of the cells include somatic cells, stem cells, progenitor cells, differentiated cells and the like. The somatic cells may be cancer cells.

Examples of the somatic cells include nerve cells, cardiomyocytes, retinal cells, hepatocytes and the like.

Examples of the stem cells include pluripotent stem cells, tissue stem cells, tissue progenitor cells and the like.

Examples of the pluripotent stem cells include induced pluripotent stem cells (iPS cells), embryonic stem cells (embryonic stem cells, ES cells), mouse cells (multiligence differential stem cells), embryonic stem cells (embryonic stem cells), and embryonic stem cells (embryonic stem cells). Examples thereof include embryonic germ cells, embryonic stem cells, and mGS cells (multipotent germ cell).

The tissue stem cells and the tissue precursor cells have self-renewal ability and belong to any of ectoderm tissue, endoderm tissue, mesoderm tissue and reproductive tissue, and are constituent cells of the organ to which they belong. A cell that exhibits limited ability to differentiate into a species.

Examples of tissue stem cells and tissue precursor cells include nerve stem cells, nerve ridge stem cells, retinal stem cells, corneal stem cells, keratinocyte epidermal stem cells, melanosite stem cells, mammary stem cells, hepatic stem cells, intestinal stem cells, airway stem cells, hematopoietic stem cells, and mesenchymal stem cells. , Cardiac stem cells, vascular endothelial precursor cells, vascular pericutaneous cells, skeletal muscle stem cells, adipose stem cells, renal precursor cells, sperm stem cells and the like.

Examples of the stem cells include the stem cells described in "Understanding Stem Cells and Regenerative Medicine" (Yodosha, by Kenji Nagafune).

The cells are preferably somatic cells, stem cells, progenitor cells or differentiated cells. The somatic cells are preferably cancer cells, nerve cells, myocardial cells, retinal cells, or hepatocytes. The stem cells are preferably pluripotent stem cells.

The average fiber diameter of the resin fibers is preferably 100 nm or more, more preferably 200 nm or more, further preferably 300 nm or more, particularly preferably 500 nm or more, preferably 10 μm or less, more preferably 5 μm or less, still more preferably 1 μm or less. .. When the average fiber diameter of the resin fibers is at least the above lower limit and at least the above upper limit, the morphological retention of the cell adhesion structure can be further enhanced, and the cell adhesion can be further enhanced.

The average fiber length of the resin fibers is not particularly limited. The average fiber length of the resin fibers may be 0.1 mm or more, 1 mm or more, 100 mm or less, or 10 mm or less.

The average fiber diameter and average fiber length of the resin fibers can be obtained by obtaining one resin fiber using a scanning electron microscope (SEM) and then averaging the fiber diameters and fiber lengths of a plurality of resin fibers. .. The average fiber diameter and the average fiber length are preferably the average of the fiber diameters and fiber lengths of 20 or more resin fibers.

The resin fiber can be produced by molding the material of the resin fiber into a fibrous form. For example, it can be produced by molding a resin fiber material into a fibrous form using an electric field spinning device.

(Cell adhesion structure)
The cell adhesion structure according to the present invention includes a core portion and a shell portion arranged on the outer surface of the core portion. In the cell adhesion structure according to the present invention, the core portion contains the above-mentioned cell adhesion resin fiber and the cells adhered on the surface of the cell adhesion resin fiber, and the shell portion is a hydrogel. Including.

The cell adhesion structure is preferably fibrous such as a string. The fibrous cell adhesion structure is sometimes called a cell fiber.

The length of the cell adhesion structure is not particularly limited, but is, for example, 1 cm or more and 100 cm or less.

FIG. 1 is a cross-sectional view schematically showing a cell adhesion structure according to an embodiment of the present invention.

The cell adhesion structure (cell fiber) 1 includes a core portion 2 and a shell portion 3 arranged on the outer surface of the core portion 2. The core portion 2 includes a plurality of cell adhesion resin fibers 21 and a plurality of cells 22. The cells 22 are adhered on the surface of the cell adhesion resin fiber 21.

The diameter of the core portion is not particularly limited, but is, for example, 1 μm or more and 1000 μm or less.

The core portion may contain a liquid medium, a growth factor-based additive, and the like.

Examples of the hydrogel include alginate gel, peptide hydrogel and agarose gel. The shell portion is preferably the hydrogel, more preferably an alginate gel.

The thickness of the shell portion is not particularly limited, but is, for example, 1 μm or more and 1000 μm or less.

The cell adhesion structure can be produced, for example, by the method described in JP-A-2018-0789717.

FIG. 2 is a diagram for explaining a method for producing a cell adhesion structure according to an embodiment of the present invention.

The microfluidic device 100 includes a first introduction port 110, a second introduction port 120, and a third introduction port 130. The material of the core portion 2 including the cell adhesion resin fiber 21 and the cells 22 is introduced from the first introduction port 110, the material of the shell portion 3 is introduced from the second introduction port 120, and the third introduction port is used. The cell adhesion structure 1 shown in FIG. 1 can be produced by introducing a liquid containing calcium chloride from 130 and injecting it.

Conventionally, in a cell adhesion structure, collagen, a mouse sarcoma extract, Matrigel, or the like has been used as a scaffold material for adhering cells. However, when a cell adhesion structure is produced using these scaffold materials, the morphological retention of the cell adhesion structure may be low.

On the other hand, by using the cell adhesion resin fiber according to the present invention as a scaffold material for adhering cells, the morphological retention of the cell adhesion structure can be enhanced. In addition, cell adhesion can be enhanced. Therefore, when cells are transported using the cell adhesion structure, the survival rate of cells can be increased.

The present invention will be described in more detail below with reference to Examples and Comparative Examples. The present invention is not limited to these examples.

The following were prepared as the materials for the resin fibers.

The content of structural units in the obtained resin was measured by ¹ H-NMR (nuclear magnetic resonance spectrum) after the resin was dissolved in DMSO-d6 (dimethylsulfoxide). Tables 1 and 2 show the content of each structural unit of the resin.

Resin X1: Synthesis example X1
To a reactor equipped with a stirrer, 300 parts by weight of polyvinyl alcohol having 2700 mL of ion-exchanged water, an average degree of polymerization of 250 and a saponification degree of 99 mol% was added and dissolved by heating while stirring to obtain a solution. To the obtained solution, 35% by weight hydrochloric acid was added as a catalyst so that the hydrochloric acid concentration was 0.2% by weight. Then, the temperature was adjusted to 15 ° C., and 22 parts by weight of n-butyraldehyde was added with stirring. Then, 148 parts by weight of n-butyraldehyde was added to precipitate a white particulate polyvinyl butyral resin. Fifteen minutes after the precipitation, 35% by weight hydrochloric acid was added so that the hydrochloric acid concentration became 1.8% by weight, and then the mixture was heated to 50 ° C. and maintained at 50 ° C. for 2 hours. Then, the solution was cooled and neutralized, and then the polyvinyl butyral resin was washed with water and dried to obtain resin X1 which is a polyvinyl butyral resin.

The obtained polyvinyl butyral resin (resin X1) had a weight average molecular weight of about 20,000, a hydroxyl group content of 28 mol%, an acetyl group content of 1 mol%, and an acetalization degree of 71 mol%.

Resin X2: Synthesis example X2
Resin X2, which is a polyvinyl butyraldehyde resin, was obtained in the same manner as in Synthesis Example X1 except that 135 parts by weight of n-butyraldehyde was used instead of 148 parts by weight of n-butyraldehyde.

The obtained polyvinyl butyral resin (resin X2) had a weight average molecular weight of about 20,000, a hydroxyl group content of 34 mol%, an acetyl group content of 1 mol%, and an acetalization degree of 65 mol%.

Resin X3: Synthesis example X3
Resin X3, which is a polyvinyl butyral resin, was obtained in the same manner as in Synthesis Example X1 except that polyvinyl alcohol containing 2 mol% of a structural unit having an amino group was used instead of polyvinyl alcohol.

The obtained polyvinyl butyral resin (resin X3) has a weight average molecular weight of about 20,000, a hydroxyl group content of 20 mol%, an acetyl group content of 1 mol%, an acetalization degree of 77 mol%, and a content of structural units having an amine structure of 0. The content was 3 mol% and the content of the structural unit having an imine structure was 1.7 mol%.

Resin X4: Synthesis example X4
A resin solution was obtained by dissolving 100 parts by weight of the polyvinyl butyral resin obtained in Example 1 and 5 parts by weight of diethylaminoethyl methacrylate in 500 parts by weight of tetrahydrofuran. 0.05 parts by weight of Irgacure 184 (manufactured by BASF) was dissolved in the obtained resin solution and applied onto a PET film. A composite resin solution was obtained by irradiating the coated object with ultraviolet rays having a wavelength of 365 nm at an integrated light intensity of 2000 mJ / cm ² using a UV conveyor device (“ECS301G1” manufactured by Eye Graphics Co., Ltd.) at 25 ° C. The obtained composite resin solution was vacuum-dried at 80 ° C. for 3 hours to obtain a resin X4 which is a graft copolymer of a polyvinyl acetal resin and a poly (meth) acrylic acid ester resin.

The obtained graft copolymer (resin X4) has a weight average molecular weight of about 60,000, a hydroxyl group content of 27 mol%, an acetyl group content of 1 mol%, an acetalization degree of 68 mol%, and a structural unit derived from diethylaminoethyl methacrylate. The rate was 4 mol%.

Resin X5: Synthesis example X5
75 parts by weight of N-isopropylacrylamide and 25 parts by weight of butyl methacrylate were dissolved in 300 parts by weight of tetrahydrofuran to obtain an acrylic monomer solution. 2 parts by weight of Irgacure 184 (manufactured by BASF) was dissolved in the obtained acrylic monomer solution and applied onto a PET film. Using a UV conveyor device (“ECS301G1” manufactured by Eye Graphics Co., Ltd.) at 25 ° C., the coated material was irradiated with ultraviolet rays having a wavelength of 365 nm so as to have an integrated light intensity of 2000 mJ / cm ^2, and a poly (meth) acrylic acid ester resin. A solution was obtained. The obtained poly (meth) acrylic acid ester resin solution was vacuum dried at 80 ° C. for 3 hours to obtain a resin X5 which is a poly (meth) acrylic acid ester resin.

The weight average molecular weight of the obtained poly (meth) acrylic acid ester resin (resin X5) is about 100,000, the content of structural units derived from butyl methacrylate is 21 mol%, and the content of structural units having an amide structure is 79. It was mol%.

Resin X6: Synthesis example X6
Poly (meth) was used in the same manner as in Synthesis Example X5 except that 90 parts by weight of methoxyethyl acrylate and 10 parts by weight of butyl methacrylate were used instead of 75 parts by weight of N-isopropylacrylamide and 25 parts by weight of butyl methacrylate. ) Resin X6, which is an acrylate resin, was obtained.

The weight average molecular weight of the obtained poly (meth) acrylic acid ester resin (resin X6) is about 80,000, the content of structural units derived from butyl methacrylate is 9 mol%, and the content of structural units derived from methoxyethyl acrylate. Was 91 mol%.

Resin X7: Synthesis example X7
Poly (meth) was used in the same manner as in Synthesis Example X5 except that 75 parts by weight of methoxyethyl acrylate and 25 parts by weight of butyl methacrylate were used instead of 75 parts by weight of N-isopropylacrylamide and 25 parts by weight of butyl methacrylate. ) Resin X7, which is an acrylate resin, was obtained.

The weight average molecular weight of the obtained poly (meth) acrylic acid ester resin (resin X7) is about 90,000, the content of structural units derived from butyl methacrylate is 23 mol%, and the content of structural units derived from methoxyethyl acrylate. Was 77 mol%.

Resin X8: Synthesis example X8
Instead of 100 parts by weight of the polyvinyl butyral resin and 5 parts by weight of diethylaminoethyl methacrylate, 70 parts by weight of polyvinyl butyral, 5 parts by weight of N-vinylpyrrolidone, and 25 parts by weight of lauryl methacrylate were used. Resin X8, which is a graft copolymer of a polyvinyl acetal resin and a poly (meth) acrylic acid ester resin, was obtained in the same manner as in Synthesis Example X4 except for these.

The obtained graft copolymer (resin X8) has a weight average molecular weight of about 70,000, a hydroxyl group content of 20 mol%, an acetyl group content of 1 mol%, an acetalization degree of 50 mol%, and a content of structural units derived from lauryl methacrylate. Was 25 mol%, and the content of the structural unit having an amide structure was 5 mol%.

Resin X9: Synthesis example X9
Instead of 100 parts by weight of the polyvinyl butyral resin and 5 parts by weight of diethylaminoethyl methacrylate, 50 parts by weight of polyvinyl butyral, 8 parts by weight of N-vinylpyrrolidone, and 42 parts by weight of lauryl methacrylate were used. Resin X9, which is a graft copolymer of a polyvinyl acetal resin and a poly (meth) acrylic acid ester resin, was obtained in the same manner as in Synthesis Example X4 except for these.

The obtained graft copolymer (resin X9) has a weight average molecular weight of about 70,000, a hydroxyl group content of 14 mol%, an acetyl group content of 0.5 mol%, an acetalization degree of 35.5 mol%, and a structure derived from lauryl methacrylate. The content of the unit was 42 mol%, and the content of the structural unit having an amide structure was 8 mol%.

Resin X10: Synthesis example X10
Instead of 100 parts by weight of the polyvinyl butyral resin and 5 parts by weight of diethylaminoethyl methacrylate, 25 parts by weight of polyvinyl butyral, 12.5 parts by weight of N-vinylpyrrolidone, and 62.5 parts by weight of lauryl methacrylate were used. Except for these, resin X10, which is a graft copolymer of a polyvinyl acetal resin and a poly (meth) acrylic acid ester resin, was obtained in the same manner as in Synthesis Example X4.

The obtained graft copolymer (resin X10) has a weight average molecular weight of about 60,000, a hydroxyl group content of 7 mol%, an acetyl group content of 0 mol%, an acetalization degree of 18 mol%, and a content of structural units derived from lauryl methacrylate. Was 62.5 mol%, and the content of the structural unit having an amide structure was 12.5 mol%.

Resin X11: Synthesis example X11
Instead of 100 parts by weight of the polyvinyl butyral resin and 5 parts by weight of diethylaminoethyl methacrylate, 10 parts by weight of polyvinyl butyral, 15 parts by weight of N-vinylpyrrolidone, and 75 parts by weight of lauryl methacrylate were used. Resin X11, which is a graft copolymer of a polyvinyl acetal resin and a poly (meth) acrylic acid ester resin, was obtained in the same manner as in Synthesis Example X4 except for these.

The obtained graft copolymer (resin X11) has a weight average molecular weight of about 70,000, a hydroxyl group content of 3 mol%, an acetyl group content of 0 mol%, an acetalization degree of 7 mol%, and a content of structural units derived from lauryl methacrylate. Was 75 mol%, and the content of the structural unit having an amide structure was 15 mol%.

Others:
Polystyrene ("Polystyrene MW125,000-250,000" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
Polylactic acid ("Polylactic acid Mw ~ 60000" manufactured by Sigma-Aldrich)
Matrigel ("Matrigel Basement Membrane Matrix" manufactured by Corning)

(Examples 1 to 11 and Comparative Examples 1 and 2)
Fabrication of resin fibers:
The resins shown in Tables 1 and 2 were dissolved in ethanol to obtain a 20% resin solution. The obtained resin solution was electrospun using an electric field spinning device at a voltage of 10 kV, a distance between needle tips of 10 cm, and a flow velocity of 0.5 mL / h to form fibers to prepare resin fibers.

Fabrication of cell adhesion structure:
A cell adhesion structure was prepared using the microfluidic device 100 shown in FIG. Specifically, a cell adhesion structure was prepared as follows. From the first inlet 110 of the microfluidic device 100, human hepatocytes (HepG2 cells) having a cell density of 1 × 10 ⁸ cells / mL are contained, and the obtained resin fibers are contained in 20% by weight (solid content weight). Phosphate buffer was introduced at a flow rate of 25 μL / min. Further, a 1.5 w / v% sodium alginate aqueous solution was introduced from the second introduction port 120 at a flow rate of 75 μL / min. Further, a 3% sucrose solution containing 100 mmol / L calcium chloride was introduced from the third inlet 130 at a flow rate of 3600 μL / min. By injecting these, a total of 5 cell adhesion structures (cell fibers) having a length of 10 cm containing resin fibers and HepG2 cells in the core portion (diameter 500 μm) and alginate gel in the shell portion (thickness 300 μm). This was prepared.

(Comparative Example 3)
A cell adhesion structure was prepared in the same manner as in Example 1 using Matrigel.

(Evaluation)
(1) Ratio (content of hydrophilic structural unit / content of hydrophobic structural unit)
In the resins X1 to X11, the ratio (content of hydrophilic structural unit / content of hydrophobic structural unit) is calculated from the content of each structural unit measured by ¹ H-NMR (nuclear magnetic resonance spectrum). did. The degree of acetalization, the amount of acetyl group, the structural unit derived from lauryl methacrylate, and the structural unit derived from butyl methacrylate are hydrophobic structural units. The amount of hydroxyl groups, the structural unit having an amine structure, the structural unit having an imine structure, the structural unit derived from diethylaminoethyl methacrylate, the structural unit having an amide structure, and the structural unit derived from methoxyethyl acrylate are hydrophilic structural units. In the table, "NA" means no data.

(2) Surface free energy 1 part by weight of each of the obtained resins X1 to X11, polystyrene and polylactic acid was dissolved in 19 parts by weight of butanol. 150 μL of the obtained solution was discharged onto the surface of a φ22 mm cover glass (“22 Maru No. 1” manufactured by Matsunami Co., Ltd.) dust-removed with an air duster, rotated at 2000 rpm for 20 seconds using a spin coater, and then 80. Vacuum dried at ° C. for 6 hours to obtain a resin film having a smooth surface. 1 μL of pure water was dropped on the surface of the obtained resin film, and a droplet image after 30 seconds was photographed using a contact angle meter (“DMo-701” manufactured by Kyowa Surface Chemistry Co., Ltd.) to obtain pure water. The contact angle θ was calculated. Similarly, 1 μL of diiodomethane was dropped on the surface of the obtained resin film, and a droplet image 30 seconds later was photographed with a contact angle meter to determine the contact angle θ of diiodomethane. From the obtained contact angle, the dispersion component γ ^d of the surface free energy and the dipole component γ ^p were calculated using the Kaelble-Uy theoretical formula.

(3) Presence or absence of phase-separated structure The obtained resin fiber was observed with an atomic force microscope (AFM, manufactured by Bruker, product number "Dimension XR"). The cantilever used was SCAN ASYST AIR. As a result, in the resin fibers obtained in Examples 8 to 11, the polyvinyl acetal resin portion as the first phase forms a sea portion, and the (meth) acrylic acid ester resin portion as the second phase forms an island portion. The forming sea-island-like phase-separated structure was observed. On the other hand, no phase-separated structure was observed in the resin fibers obtained in Examples 1 to 7 and Comparative Examples 1 to 3.

(4) Average Fiber Diameter of Resin Fiber The obtained resin fiber was observed using a scanning electron microscope (SEM). The fiber diameters of 20 or more resin fibers were measured, and the average fiber diameter of the resin fibers was calculated from the average value.

(5) Morphological retention Five cell adhesion structures having a length of 10 cm were allowed to stand in a liquid medium for 24 hours. The morphology of the cell adhesion structure after 24 hours was visually observed. The morphological retention of the cell adhesion structure was judged according to the following criteria.

<Criteria for morphological retention>
○○○: 5 out of 5 cell adhesion structures retain morphology ○○: 4 out of 5 cell adhesion structures retain morphology ○: 3 out of 5 Cell adhesion structure of book retains morphology ×: 2 or less of 5 cell adhesion structures retain morphology

(6) Cell Adhesion 1 mL of phosphate buffer containing 20% by weight (solid content weight) of the obtained resin fiber was applied to a Φ22 mm cover glass (manufactured by Matsunami Co., Ltd.) and dried at room temperature for 24 hours to carry a resin fiber. Got The carrier was fitted into the wells of a 12-well plate, and 3 × 10 ⁵ HepG2 cells suspended in phosphate buffer were seeded. The plate was allowed to stand in a CO ₂ incubator at 37 ° C. for 30 minutes. It was then washed twice with 1.5 mL phosphate buffer. Established cells were exfoliated using 1.0 mL of TryPLE Express exfoliating solution, and the number of cells was counted using a cell counter (“Nucleocounter NC-3000” manufactured by Chemometec) to obtain the number of cells after standing for 30 minutes. .. The cell adhesion rate was calculated by the following formula.

Cell adhesion rate (%) = (number of cells after standing for 30 minutes ÷ number of seeded cells) x 100

<Criteria for cell adhesion>
〇 〇… Cell adhesion rate is 60% or more 〇… Cell adhesion rate is 30% or more and less than 60% ×… Cell adhesion rate is less than 30%

Details and results are shown in Tables 1 and 2 below.

1 ... Cell adhesion structure (cell fiber)
2 ... Core part 3 ... Shell part 21 ... Resin fiber for cell adhesion 22 ... Cell 100 ... Microfluidic device 110 ... First introduction port 120 ... Second introduction port 130 ... Third introduction port

Claims (10)

A resin fiber for cell adhesion used for adhering cells.
A resin fiber for cell adhesion, wherein the resin fiber for cell adhesion is a resin fiber containing a resin having a polyvinyl acetal skeleton or a poly (meth) acrylic acid ester skeleton. The dispersion component γ ^d of the surface free energy of the resin film formed by using the material of the resin fiber for cell adhesion is 24.5 mJ / m ² or more and less than 45.0 mJ / m ² , and the surface free energy bipolar element. The resin fiber for cell adhesion according to claim 1, wherein the component γ ^p is 1.0 mJ / m ² or more and less than 20.0 mJ / m ² . The cell adhesion resin fiber according to claim 1 or 2, wherein the cell adhesion resin fiber is a resin fiber of a resin having a polyvinyl acetal skeleton. The resin fiber for cell adhesion according to any one of claims 1 to 3, which has a phase-separated structure. Any of claims 1 to 4, wherein the resin having a polyvinyl acetal skeleton or a poly (meth) acrylic acid ester skeleton has a main chain having a polyvinyl acetal skeleton and a graft chain having a poly (meth) acrylic acid ester skeleton. The resin fiber for cell adhesion according to item 1. The resin fiber for cell adhesion according to any one of claims 1 to 5, wherein the ratio of the content of the hydrophilic functional group to the content of the hydrophobic functional group is 0.1 or more and 1.5 or less. .. Claimed that the ratio of the content of hydrophilic functional groups to the content of hydrophobic functional groups in the resin having a polyvinyl acetal skeleton or poly (meth) acrylic acid ester skeleton is 0.1 or more and 1.5 or less. Item 2. The resin fiber for cell adhesion according to any one of Items 1 to 6. The resin having a polyvinyl acetal skeleton or a poly (meth) acrylic acid ester skeleton has a hydrophilic structural unit and a hydrophobic structural unit.
The cell adhesion resin according to any one of claims 1 to 7, wherein the ratio of the content of the hydrophilic structural unit to the content of the hydrophobic structural unit is 0.1 or more and 1.5 or less. fiber. The resin fiber for cell adhesion according to any one of claims 1 to 8, wherein the average fiber diameter is 100 nm or more and 10 μm or less. A core portion and a shell portion arranged on the outer surface of the core portion are provided.
The core portion contains the cell adhesion resin fiber according to any one of claims 1 to 9 and cells adhered on the surface of the cell adhesion resin fiber.
A cell adhesion structure in which the shell portion contains a hydrogel.

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