Sheet for adhering stem cell

Abstract

To provide a sheet for adhering a stem cell capable of stably holding a stem cell.SOLUTION: A sheet for adhering a stem cell comprises a nonwoven fabric, where the nonwoven fabric has a laminated structure including: a first layer which is constituted of a fiber having biocompatible polymers as a main component; and a second layer which is constituted of a fiber having biocompatible polymers as a main component, and constituted of a fiber having a fiber diameter larger than that of a fiber constituting the first layer, and the biocompatible polymers constituting the first layer and the second layer include a polymer material of the same kind.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The disclosure in the present application relates to a sheet for stem cell adhesion.

Background Art

[0002] In recent years, in the field of regenerative medicine, development of tissue regeneration promoting materials that can hold cells inside and promote tissue regeneration by being implanted in the body has been progressing. For example, Patent Document 1 discloses a sheet-like tissue regeneration promoting material having at least one member selected from the group consisting of white blood cells and platelets on its surface. Further, Patent Document 2 discloses a liquid tissue regeneration promoting material obtained by mixing powder of a polymer material and cells.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the tissue regeneration promoting materials disclosed in Patent Documents 1 and 2, since a porous body or powder of a polymer material is used, there is a problem that it is difficult to stably hold mesenchymal stem cells having a high tissue regeneration ability among cells. Such a problem exists not only when holding mesenchymal stem cells with a tissue regeneration promoting material but also when holding other stem cells.

[0005] The disclosure in the present application is made based on such a background, and an object thereof is to provide a sheet for stem cell adhesion capable of stably holding stem cells.

Means for Solving the Problems

[0006] The disclosure in this application relates to a sheet for stem cell adhesion as shown below. (1) A sheet for stem cell adhesion comprising a nonwoven fabric, wherein the nonwoven fabric comprises a first layer composed of fibers mainly made of a biocompatible polymer, and a second layer composed of fibers mainly made of a biocompatible polymer and having a fiber diameter thicker than that of the fibers constituting the first layer, and has a laminated structure including them, and the biocompatible polymers constituting the first layer and the second layer contain the same type of polymer material. A sheet for stem cell adhesion. (2) The sheet for stem cell adhesion according to (1) above, wherein the polymer material is at least one selected from the group consisting of polylactic acid, polycaprolactone, chitin, chitosan, polyglycolic acid, and copolymers thereof. The sheet for stem cell adhesion according to (1) above. (3) The sheet for stem cell adhesion according to (2) above, wherein the polymer material is at least one selected from the group consisting of polylactic acid, polycaprolactone, and a copolymer of polylactic acid and polycaprolactone. The sheet for stem cell adhesion according to (2) above. (4) The sheet for stem cell adhesion according to (1) above, wherein the polymer materials of the biocompatible polymers constituting the first layer and the second layer contain the same type of polymer material at a ratio of at least 25% or more. The sheet for stem cell adhesion according to (1) above. (5) The sheet for stem cell adhesion according to (2) above, wherein the polymer materials of the biocompatible polymers constituting the first layer and the second layer contain the same type of polymer material at a ratio of at least 25% or more. The sheet for stem cell adhesion according to (2) above. (6) The sheet for stem cell adhesion according to (3) above, wherein the polymer materials of the biocompatible polymers constituting the first layer and the second layer contain the same type of polymer material at a ratio of at least 25% or more. The sheet for stem cell adhesion according to (3) above. (7) The sheet for stem cell adhesion according to any one of (4) to (6) above, wherein the polymer materials of the biocompatible polymers constituting the first layer and the second layer are 100% the same type of material. The sheet for stem cell adhesion according to any one of (4) to (6) above. (8) The fiber diameter of the fibers constituting the first layer is 200 nm or more and 5 μm or less. The fiber diameter of the fibers constituting the second layer is larger than the fiber diameter of the fibers constituting the first layer and 30 μm or less. and is in the range of The stem cell adhesion sheet according to any one of (1) to (7) above. (9) The basis weight of the first layer is 0.2 g / m 2 or more and 4 g / m 2 or less. The basis weight of the second layer is 2 g / m 2 or more and 30 g / m 2 or less. and is in the range of The stem cell adhesion sheet according to any one of (1) to (8) above.

Advantages of the Invention

[0007] With the stem cell adhesion sheet disclosed in the present application, stem cells can be stably retained.

Brief Description of the Drawings

[0008]

Figure 1

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BEST MODE FOR CARRYING OUT THE INVENTION

[0009] The stem cell adhesion sheet disclosed in the present application will be described below with reference to the drawings. Note that the position, size, range, etc. of each component shown in the drawings may not represent the actual position, size, range, etc. for the sake of easy understanding. Therefore, the disclosure of the present application is not necessarily limited to the position, size, range, etc. disclosed in the drawings.

[0010] Also, in this specification, (1) A numerical range represented by “~” means a range including the numerical values described before and after “~” as the lower limit value and the upper limit value, (2) Regarding numerical values, numerical ranges, and qualitative expressions (for example, expressions such as “identical” and “the same”), they indicate numerical values, numerical ranges, and properties including generally acceptable errors in the relevant technical field, (3) When described as “substantially XX”, it is interpreted to include not only the exact XX but also shapes that are grasped as approximately XX.

[0011] (Embodiments of the Stem Cell Adhesion Sheet) With reference to FIGS. 1 to 4, the outline of the stem cell adhesion sheet 10 according to the embodiment will be described. FIGS. 1 to 4 are perspective views showing the configuration of an example of the stem cell adhesion sheet according to the embodiment.

[0012] The stem cell adhesion sheet according to the embodiment is used for adhering stem cells. The sheet after the stem cells are adhered (hereinafter sometimes referred to as the "tissue regeneration promoting sheet") has the effect of promoting tissue regeneration at the damaged site by being implanted at the damaged site in the body. The stem cell adhesion sheet according to the embodiment includes a non-woven fabric composed of fibers having a fine diameter to which stem cells adhere, for example, microfibers. The non-woven fabric is a sheet formed by entangling fine-diameter fibers without weaving. Since the non-woven fabric can be freely deformed, it is suitable for embedding or attaching according to the shape of the damaged site. The tissue regeneration promoting sheet can be attached to or embedded in any organ or tissue, for example, the heart, blood vessels, lungs, trachea, esophagus, stomach, small intestine, large intestine, liver, kidney, bladder, bone, muscle, and skin. The tissue regeneration promoting sheet can function as a scaffold for promoting the growth of specific cells in the body.

[0013] As shown in FIG. 1, the stem cell adhesion sheet 10 includes a first layer 12 composed of fibers mainly made of a biocompatible polymer and a second layer 14 composed of fibers mainly made of a biocompatible polymer. The second layer 14 is composed of fibers having a fiber diameter thicker than the fibers constituting the first layer 12.

[0014] As shown in FIG. 3 of Japanese Patent Application Laid-Open No. 2023-47494, the stem cells are captured by the stem cell adhesion sheet 10 by adhering to the fibers rather than being trapped in the gaps between the fibers constituting the non-woven fabric. The procedure for attaching the stem cells to the stem cell adhesion sheet 10 will be described later, but the stem cells can adhere to both the first layer 12 and the second layer 14. Further, since the second layer 14 is composed of fibers thicker than the fiber diameter of the fibers constituting the first layer 12, it functions as a reinforcing sheet that adheres the stem cells and reinforces the first layer 12. When the stem cell adhesion sheet is formed only of the first layer 12 having a small fiber diameter, it is likely to curl when exposed to the cell suspension. The stem cell adhesion sheet 10 according to the embodiment improves the handleability of the stem cell adhesion sheet 10 by laminating the first layer 12 and the second layer 14. The first layer 12 and the second layer 14 may be laminated so as not to be easily separated. Although not limited, they may be joined by intertwining the fibers during the production of the non-woven fabric, or the separately produced first layer 12 and second layer 14 may be joined to each other by an adhesive or heat fusion.

[0015] FIG. 1 shows an example of the stem cell adhesion sheet 10 in which one layer of the first layer 12 and the second layer 14 are laminated respectively, but the number of the first layer 12 and the second layer 14 is not particularly limited as long as the cell suspension containing the stem cells can be filtered and the stem cells can be adhered to the stem cell adhesion sheet 10.

[0016] For example, as shown in FIG. 2, the first layer 12 may be sandwiched between two upper and lower second layers 14. Further, as shown in FIG. 3, a plurality of layers of the first layer 12 (two layers in the example shown in FIG. 3) may be laminated between the two upper and lower second layers 14. Further, as shown in FIG. 4, the first layer 12 and the second layer 14 may be laminated alternately.

[0017] The first layer 12 and the second layer 14 are composed of fibers mainly composed of a biocompatible polymer. In this specification, the "biocompatible polymer" means a polymer that has an affinity for living tissues and organs and does not cause foreign body reactions or rejection reactions when applied to a living body.

[0018] The polymer materials used in producing biocompatible polymers are not particularly limited as long as they have high biocompatibility. Although not limited, examples include polylactic acid (PLA), polycaprolactone (PCL), chitin, chitosan, polyglycolic acid (PGA), and their copolymers.

[0019] Among the polymer materials exemplified above, polycaprolactone is a semi-crystalline and biodegradable thermoplastic polyester and can also be suitably used in the production of non-woven fabrics. Polycaprolactone may be, for example, poly-ε-caprolactone. The molecular weight of polycaprolactone may be a molecular weight suitable for injection molding, and for example, the range of 70,000 to 200,000 can be mentioned. Also, the molecular weight of polylactic acid is 50,000 to 200,000, and the molecular weight of polyglycolic acid is 50,000 to 500,000.

[0020] The fibers constituting the first layer 12 and the second layer 14 may be composed only of the biocompatible polymer formed of the above polymer material, or may contain other substances. As other substances, for example, drugs that promote tissue regeneration or other biodegradable polymers may be used. Drugs that promote tissue regeneration include, for example, hydroxyapatite (calcium hydrogen phosphate), tricalcium phosphate, etc. Other biodegradable polymers include, for example, polydioxanone, etc. The mass ratio of the biocompatible polymer in the fiber may be 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, 100%, etc.

[0021] Incidentally, although it is unapproved in Japan, a non-woven fabric made of 100% polylactic acid (PLA) has been approved by the pharmaceutical affairs in the United States. Also in Japan, a copolymer of 50% polycaprolactone (PCL) and 50% polylactic acid (PLA) is used as a synthetic artificial dura mater (trade name: Seam Dura, manufactured by Gunze), and a copolymer of 25% polycaprolactone (PCL) and 75% polylactic acid (PLA) is used as an absorbable suture (trade name: P(LA / CL) suture, manufactured by Gunze), and both have been approved by the pharmaceutical affairs. That is to say, polylactic acid and polycaprolactone can be said to be polymer materials whose safety in humans has been confirmed. Therefore, from the perspective of reducing the burden of applying for pharmaceutical approval including safety tests when applied to the living body, as polymer materials, polylactic acid, polycaprolactone, and copolymers of polylactic acid and polycaprolactone are more preferable.

[0022] The biocompatible polymers constituting the first layer 12 and the second layer 14 preferably contain the same type of polymer material. When the tissue regeneration promoting sheet is implanted at the damaged site in the living body, the biocompatible polymer is decomposed in the living body. At that time, if the polymer materials of the first layer 12 and the second layer 14 are different, differences may occur in the environment at the implantation site such as the decomposition rate, decomposition products, and pH. When the biocompatible polymers constituting the first layer 12 and the second layer 14 contain the same type of polymer material, it is expected that the difference in environmental changes after decomposition at the implantation site will be reduced.

[0023] It is expected that the same type of polymer material will have a greater effect as its proportion increases. Although not limited, the proportion of the same type in the polymer materials of the biocompatible polymers constituting the first layer 12 and the second layer can be 5% or more, 10%, 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, 45%, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% or more, 85% or more, 90% or more, 95% or more, 100%, etc.

[0024] In addition, in this specification, the ratio of the same type of polymer material means the mass of the component when the mass of the polymer material in the first layer 12 is set to 100 and the mass of the component when the mass of the polymer material in the second layer 14 is set to 100, when comparing them. When the polymer material is a copolymer, the same type of components contained in the copolymer are compared, and the mass of the component with the smaller amount may be taken as the ratio of the same type of polymer material. The same type may be one type or two or more types. When two or more types of the same type of polymer material (components) are included, the ratios may be added together. More specific examples when the polymer materials are X, Y, and Z are shown below. Note that the description "X+Y" means a copolymer of X and Y. JPEG2025099519000002.jpg55133

[0025] The fiber diameter of the fibers constituting the first layer 12 and the fiber diameter of the fibers constituting the second layer 14 are not particularly limited as long as the fiber diameter of the fibers constituting the first layer 12 is smaller than the fiber diameter of the fibers constituting the second layer 14, the stem cells can adhere, and there are no problems in handling the stem cell adhesion sheet. Although not limited, examples of the lower limit value of the fiber diameter of the fibers constituting the first layer 12 include 200 nm or more, 300 nm or more, 400 nm or more, 500 nm or more, 600 nm or more, 700 nm or more, 800 nm or more, 900 nm or more, 1 μm or more, etc. On the other hand, examples of the upper limit value include 5 μm or less, 4.75 μm or less, 4.5 μm or less, 4.25 μm or less, 4 μm or less, etc. The lower limit value of the fiber diameter of the fibers constituting the second layer 14 may be larger than the fiber diameter of the fibers constituting the first layer 12, and examples of the upper limit value include 30 μm or less, 27.5 μm or less, 25 μm or less, 22.5 μm or less, 20 μm or less, 17.5 μm or less, 15 μm or less, etc. Also, when the fiber diameter of the fibers constituting the first layer 12 is set to 1, the fiber diameter of the fibers constituting the second layer 14 is, although not limited, 1.2 times or more, 1.4 times or more, 1.6 times or more, 1.8 times or more, 2 times or more, 3 times or more, 4 times or more, 5 times or more, 6 times or more, 7 times or more, 8 times or more, 9 times or more, 10 times or more, etc.

[0026] The first layer 12 can increase the amount of stem cells attached as the basis weight increases, but the filtration of the cell suspension gradually becomes difficult. The basis weight of the first layer 12 may be determined in consideration of the amount of stem cells attached and the ease of production. Although not limited, the lower limit of the basis weight of the first layer 12 is 0.2 g / m 2 or more, 0.4 g / m 2 or more, 0.6 g / m 2 or more, 0.8 g / m 2 or more, 1 g / m 2 or more, etc. can be mentioned. As the upper limit, 4 g / m 2 or less, 3 g / m 2 or less, 2.8 g / m 2 or less, 2.6 g / m 2 or less, 2.4 g / m 2 or less, 2.2 g / m 2 or less, 2.0 g / m 2 or less, etc. can be mentioned.

[0027] On the other hand, as described above, the second layer 14 functions as a reinforcing sheet that attaches stem cells and reinforces the first layer 12. Therefore, the basis weight of the second layer 14 may be appropriately determined within a range considering handling properties along with the attachment of stem cells. Although not limited, the lower limit is 2 g / m 2 or more, 2.5 g / m 2 or more, 3 / m 2 or more, 3.5 g / m 2 or more, 4 g / m 2 or more, 4.5 g / m 2 or more, 5 / m 2 or more, 5.5 g / m 2 or more, 6 g / m 2 or more, 6.5 g / m 2 or more, 7 g / m 2 or more, 7.5 / m 2 or more, 8 g / m 2 or more, 8.5 g / m 2 or more, 9 g / m 2 or more, 9.5 / m 2 or more, 10 / m 2 or more, etc. can be mentioned. The upper limit is 30 g / m 2 or less, 29 g / m 2 or less, 28 g / m 2 or less, 27 g / m 226 g / m or less 2 25 g / m or less 2 24 g / m or less 2 23 g / m or less 2 22 g / m or less 2 21 g / m or less 2 20 g / m or less 2 Examples include the above and so on. Regarding the fiber diameter, the fiber diameter of the fibers constituting the second layer 14 needs to be thicker than the fiber diameter of the fibers constituting the first layer 12. On the other hand, regarding the basis weight, as long as the handleability is good and the filtration of stem cells is not hindered, the basis weight of the first layer 12 may be smaller, the same, or larger than the basis weight of the second layer 14.

[0028] The thickness of the laminated structure in which the first layer 12 and the second layer 14 are laminated may be appropriately determined while considering the handleability by tweezers. Although not limited, examples of the thickness of the laminated structure include 200 μm or more, 300 μm or more, 400 μm or more, 500 μm or more, 600 μm or more, 700 μm or more, and so on. On the other hand, examples of the upper limit of the thickness of the laminated structure include 1700 μm or less, 1600 μm or less, 1500 μm or less, 1400 μm or less, and so on. Also, since the second layer 14 functions as a reinforcing sheet, there is no problem with handleability even if the first layer 12 is thin. Examples of the thickness of the first layer 12 in the above laminated structure include 10 μm or more, 20 μm or more, 40 μm or more, 60 μm or more, 80 μm or more, 100 μm or more, and so on. Examples of the upper limit value include less than 200 μm, 180 μm or less, 160 μm or less, 140 μm or less, and so on.

[0029] The stem cells to be attached to the stem cell attachment sheet 10 include mesenchymal stem cells (MSC), cells differentiated from mesenchymal stem cells, ES (Embryonic Stem) cells, iPS (induced Pluripotent Stem) cells, and the like. Mesenchymal stem cells are somatic stem cells having the ability to differentiate into cells belonging to the mesenchymal system, and may be derived from any of adipose tissue, periosteum, synovium, cancellous bone, bone marrow, amnion, umbilical cord blood, and placenta. The stem cells attached to the non-woven fabric may be of one type or a combination of two or more types.

[0030] The stem cells to be attached to the stem cell attachment sheet 10 may be those collected from a patient or those that have been established in culture. To culture stem cells in vitro, for example, a medium containing fetal bovine serum (FBS) or human serum, preferably human serum derived from the patient, or a serum-free medium may be used. The stem cells cultured in the medium may be directly attached to the non-woven fabric, or the stem cells may be differentiated to express specific cells, such as osteoblasts, and then attached to the non-woven fabric. To express specific cells, for example, a differentiation inducer may be added to the medium of the stem cells.

[0031] In addition, it is not always necessary to pre-attach stem cells to the stem cell attachment sheet 10 disclosed in the present application. After the stem cell attachment sheet 10 is placed at the damaged site in the body, stem cells may be attached to the stem cell attachment sheet in the body by administering a cell suspension containing stem cells to the vascular system.

[0032] Next, a specific procedure for attaching stem cells to the stem cell attachment sheet 10 according to the embodiment will be described. To attach stem cells to the stem cell attachment sheet 10, the cell suspension containing stem cells may be brought into contact for a while, but in order to suppress the decrease in the growth factor production ability during stem cell culture, it is preferably carried out according to the following procedure.

[0033] First, as shown in FIG. 5, between a pair of holders 20 constituting the filtration device, a stem cell adhesion sheet 10 according to the embodiment is set. Each holder 20 is configured such that the cell suspension can flow out or in. In the example shown in FIG. 5, when the cell suspension is flowed from one holder 20 toward the other holder 20, the cell suspension contacts the first layer 12.

[0034] Next, the cell suspension containing stem cells is slowly dropped one drop at a time from above, and the cell suspension is filtered through the first layer 12. The filtration rate can be, for example, the rate of dropping 1 ml of the cell suspension over 2 to 3 minutes. At this time, the stem cells contained in the dropped cell suspension adhere to the fibers of the first layer 12 by themselves. Although the exact mechanism is unknown, when the cell suspension containing stem cells is gradually filtered through the stem cell adhesion sheet, the stem cells stably adhere to each fiber, and the attached stem cells are activated to promote the production of growth factors. Note that the stem cells that pass through without adhering to the first layer 12 can adhere to the second layer 14, but all the stem cells may adhere to the first layer 12 by adjusting conditions and the like. That is, although the second layer 14 has the function of adhering stem cells, the adhesion of stem cells to the second layer 14 is not essential when used as the tissue regeneration promoting sheet.

[0035] The above embodiments are illustrative, and the present invention is not limited thereto. Various embodiments are possible without departing from the spirit of the invention described in the claims. The components described in the embodiments can be freely combined. Also, inventions equivalent to the invention described in the claims are included in the present invention.

[0036] For example, although illustration is omitted, the stem cell adhesion sheet 10 shown in FIG. 5 may be the stem cell adhesion sheet 10 shown in FIGS. 2 to 4. Further, the cell suspension may be flowed from the second layer 14 side. Further, in the examples shown in FIGS. 2 to 4, a laminated structure of three or more layers is shown, but as the types of layers, there are two types, the first layer 12 and the second layer 14. Alternatively, a third layer having different polymer materials, fiber diameter sizes, etc. constituting the first layer 12 and the second layer 14 may be laminated. As long as the first layer 12 and the second layer 14 disclosed in the present application are included, other layers may be included.

[0037] Examples will be given below to specifically explain the embodiments disclosed in the present application. However, these examples are merely for the purpose of explaining the embodiments and do not represent a limitation or restriction of the technical scope disclosed in the present application.

Example

[0038] <Example 1> [Production of various nonwoven fabrics] A copolymer of polycaprolactone (PCL) and polylactic acid (PLA) that has already been used clinically as an artificial dura mater in a ratio of 50:50 was used as the polymer material for the first layer 12 and the second layer 14. Using a commercially available nonwoven fabric production apparatus, nonwoven fabrics with the fiber diameters, basis weights, and thicknesses shown in Table 1 below were produced.

Table 1

[0039] [Adsorption (capture) of stem cells onto the produced nonwoven fabric] Next, the produced nonwoven fabric was used as a stem cell adhesion sheet. With the stem cell adhesion sheet sandwiched in a filtration sterilization holder, a cell suspension containing human adipose-derived mesenchymal stem cells (ADSC. Promocell, product code C-12977.) was passed through to attach human mesenchymal stem cells to the stem cell adhesion sheet, and the adhesion rate was evaluated. A Swinex filter holder (Merck Millipore) was used for the filtration sterilization holder. Also, the cell suspension was dropped one drop at a time. Experiments were conducted on three samples each.

[0040] The results of the adhesion (capture) experiment are also shown in Table 1. The capture rate is a value obtained by measuring the number of cells before and after filtration using a hemocytometer and calculating (number of cells before filtration - number of cells after filtration) / number of cells before filtration × 100. As is clear from the results shown in Table 1, it was confirmed that stem cells can be adhered with very high efficiency by using the stem cell adhesion sheet comprising the nonwoven fabric produced in Example 1.

[0041] <Example 2> A nonwoven fabric was produced in the same procedure as in Example 1, except that 100% polycaprolactone was used instead of the polymer material of Example 1. The sizes of the first and second layers of the produced nonwoven fabric are as follows. Also, the cell capture rate was 100%. · First layer: fiber diameter 0.5 μm, basis weight 2 g / m 2 , thickness 100 μm. · Second layer: fiber diameter 5 μm, basis weight 10 g / m 2 , thickness 500 μm.

[0042] [Confirmation of growth factor production ability] Next, using the nonwoven fabric produced in Example 2, a tissue regeneration promoting sheet was produced by adhering stem cells to the nonwoven fabric in the same procedure as in Example 1. The produced tissue regeneration promoting sheet was transferred to a petri dish containing a medium and cultured for 4 weeks. Also, as a comparison, stem cells (ADSCs) were directly cultured in a petri dish for 4 weeks. After culturing for 4 weeks, the expression level of vascular endothelial growth factor (VEGF) was measured using ELISA. The results are shown in Fig. 6.

[0043] <Example 3> The ability to produce growth factors was confirmed using the nonwoven fabric produced in the same manner as in Example 2, except that the polymer material of Example 1 was used. The sizes of the first and second layers of the produced nonwoven fabric are as follows. Also, the cell capture rate was 99.7%. The results are shown in Fig. 7. · First layer: fiber diameter 0.5 μm, basis weight 2 g / m 2 , thickness 100 μm. · Second layer: fiber diameter 4 μm, basis weight 10 g / m 2, thickness 500 μm.

[0044] As is apparent from FIGS. 6 and 7, when the stem cells were attached to the stem cell attachment sheet disclosed in the present application and cultured, it was confirmed that the stem cells were activated as compared with the case where the stem cells were cultured in the medium as they were (ADSC in FIGS. 6 and 7). Further, since the stem cell attachment sheet disclosed in the present application has a laminated structure of a first layer and a second layer having a fiber diameter thicker than that of the first layer, it was confirmed that there were no particular problems with the handleability of the stem cell attachment sheet in a series of experiments.

[0045] <Example 4> Instead of the polymer material of Example 1, a copolymer of polycaprolactone (PCL) and polylactic acid (PLA) that has already been used clinically as an absorbable suture at a ratio of 25:75 was used as the polymer material for the first layer 12 and the second layer 14, and a nonwoven fabric was produced in the same procedure as in Example 1, and the adsorption (capture) of stem cells was performed. Table 2 shows the fiber diameters, basis weights, and thicknesses of the first layer and the second layer, as well as the number of laminated sheets and the capture rate of stem cells.

[0046]

Table 2

[0047] As is apparent from the results shown in Table 2, it was confirmed that stem cells can be attached with very high efficiency by using the stem cell attachment sheet provided with the nonwoven fabric produced in Example 4.

[0048] <Comparative Example 1> Only polycaprolactone was used as the polymer material, and a nonwoven fabric having only a first layer was produced. The size of the produced nonwoven fabric is as follows. · First layer: fiber diameter 0.5 μm, basis weight 2 g / m 2 , thickness 100 μm.

[0049] An attempt was made to set the produced nonwoven fabric in a holder, but the handleability was poor and it could not be set in the holder.

[0050] <Comparative Example 2> Using the polymer material described in Example 4, a nonwoven fabric was produced in the same procedure as in Example 1 except that the fiber diameter, basis weight, thickness, and number of laminated layers shown in Table 3 below were set to 1, and adsorption (capture) of stem cells was performed. The capture rate is also shown in Table 3 below.

[0051]

Table 3

[0052] As shown in Table 3, since the fiber diameter of the fibers constituting the nonwoven fabric produced in Comparative Example 2 is quite close to the fiber diameter of the second layer in Examples 1 to 4, even when the basis weight is almost the same as that in Comparative Example 1, there was no particular problem in handleability. Also, in Comparative Example 2, although the capture rate of stem cells was lower than that in Examples 1 to 4, a predetermined amount of stem cells could be captured. Therefore, it was confirmed that the second layer of the stem cell adhesion sheet disclosed in the present application exhibits the function of adhering (capturing) stem cells and the reinforcing function of reinforcing the first layer. From the results shown in Table 3, it was confirmed that if there is no problem even when the capture rate of stem cells is low, by making the fiber diameter thicker than a predetermined value, the nonwoven fabric can function as a stem cell adhesion sheet even if it is a single layer.

[0053] From the above results, rather than producing a stem cell adhesion sheet with only the first layer having a small fiber diameter, by adopting a laminated structure with a second layer composed of fibers having a fiber diameter thicker than that of the first layer, it was confirmed that the handleability and the capture efficiency of stem cells when attaching stem cells to the stem cell adhesion sheet are improved.

Explanation of Reference Numerals

[0054] 10 Stem cell adhesion sheet 12 First layer 14 Second layer 20 Holder

Claims

1. A stem cell adhesion sheet comprising a non-woven fabric, wherein the non-woven fabric comprises a first layer composed of fibers mainly composed of a biocompatible polymer, and a second layer composed of fibers mainly composed of a biocompatible polymer and having a fiber diameter larger than that of the fibers constituting the first layer, and has a laminated structure including the above, and the biocompatible polymers constituting the first layer and the second layer contain the same type of polymer material Stem cell adhesion sheet.

2. The stem cell adhesion sheet according to claim 1, wherein the polymer material is at least one selected from the group consisting of polylactic acid, polycaprolactone, chitin, chitosan, polyglycolic acid, and copolymers thereof. The stem cell adhesion sheet according to claim 1.

3. The stem cell adhesion sheet according to claim 2, wherein the polymer material is at least one selected from the group consisting of polylactic acid, polycaprolactone, and a copolymer of polylactic acid and polycaprolactone. The stem cell adhesion sheet according to claim 2.

4. The stem cell adhesion sheet according to claim 1, wherein the polymer materials of the biocompatible polymers constituting the first layer and the second layer contain the same type of polymer material at a ratio of at least 25% or more. The stem cell adhesion sheet according to claim 1.

5. The stem cell adhesion sheet according to claim 2, wherein the polymer materials of the biocompatible polymers constituting the first layer and the second layer contain the same type of polymer material at a ratio of at least 25% or more. The stem cell adhesion sheet according to claim 2.

6. The stem cell adhesion sheet according to claim 3, wherein the polymer materials of the biocompatible polymers constituting the first layer and the second layer contain the same type of polymer material at a ratio of at least 25% or more. The stem cell adhesion sheet according to claim 3.

7. The stem cell adhesion sheet according to any one of claims 4 to 6, wherein the polymer materials of the biocompatible polymers constituting the first layer and the second layer are 100% of the same type of material. The stem cell adhesion sheet according to any one of claims 4 to 6.

8. The fiber diameter of the fibers constituting the first layer is 200 nm or more and 5 μm or less, The fiber diameter of the fibers constituting the second layer is larger than the fiber diameter of the fibers constituting the first layer and 30 μm or less, and is in the range of The stem cell adhesion sheet according to any one of claims 1 to 6.

9. The basis weight of the first layer is 0.2 g / m ２ or more and 4 g / m ２ or less. The basis weight of the second layer is 2 g / m ２ or more and 30 g / m ２ or less and is in the range of The stem cell adhesion sheet according to any one of claims 1 to 6.

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