Tissue body forming device and tissue body forming method

Abstract

To provide a tissue body forming device and a tissue body forming method for forming a connective tissue body efficiently in an environment whose size is limited.SOLUTION: A tissue body forming device includes a first partition member 11 and a second partition member 21. A plurality of first through-holes 14 penetrating from an exterior surface 13 to an interior surface 12 are formed in the first partition member 11. A groove 24 sandwiched by a groove side wall and having a groove opening 24A on the opposite surface 22 is formed in the second partition member 21. The opening dimensions of the first though-holes 14 are 0.02-2.5 mm. The depth of the first through-holes 14 is 0.1-2.0 mm. The ratio occupied by the opening of the first through-holes 14 in a unit area of the exterior surface 13 is 4-70%. The distance between the opposite surface 22 and the interior surface 12 is equal to or less than the width of the groove side wall, and is equal to or less than 0.5 mm. The groove 24 is communicated with the plurality of first through-holes 14.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a tissue forming apparatus for forming a connective tissue body and a method for forming a tissue body using the tissue forming apparatus.

Background Art

[0002] The self-defense function of the body is covered with a capsule mainly composed of fibroblasts and collagen to cover foreign substances in the body. One type of regenerative medicine, which is a medical treatment for reviving lost tissues and organs, is to form a living body-derived connective tissue body using the self-defense function from living cells on a tissue forming apparatus after implanting the tissue forming apparatus as a foreign substance into the living body (see, for example, Patent Documents 1 to 4). A first example of the tissue forming apparatus includes two tissue forming surfaces facing each other. The two tissue forming surfaces divide a flat space or a valve-shaped space. The biological tissue material that enters between the two tissue forming surfaces forms a connective tissue body so as to fill the space (see, for example, Patent Documents 5 and 6).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, the technology for forming connective tissue constructs has reached the stage of verifying safety and effectiveness as regenerative medicine, so to speak, the stage of clinical research. One of the new issues brought about by the clinical research stage for the technology of forming connective tissue constructs is to efficiently form connective tissue constructs in an environment with limited size. The above-described tissue construct forming device enables the formation of connective tissue constructs in an environment where biological tissue materials are present. On the other hand, the environment for forming connective tissue constructs, such as the biological species and the number of living bodies recognized in clinical research, is greatly lacking from the perspective of evaluating a large number of items. And the technology for efficiently forming connective tissue constructs in an environment with limited size solves the environmental deficiency in clinical research and greatly promotes the popularization of regenerative medicine using the tissue construct forming device itself.

Means for Solving the Problem

[0005] The tissue construct forming device for solving the above problem is a tissue construct forming device that forms connective tissue constructs in an environment where biological tissue materials are present, and includes a first partition member having an outer surface in contact with the environment and an inner surface opposite to the outer surface, and a second partition member having a facing surface facing the inner surface. A plurality of through holes penetrating from the outer surface to the inner surface are formed in the first partition member, and a groove having a groove opening on the facing surface sandwiched between groove side walls is formed in the second partition member. The opening dimension of the through hole is 0.02 mm or more and 2.5 mm or less, the depth of the through hole is 0.1 mm or more and 2.0 mm or less, the ratio of the opening of the through hole occupying the unit area of the outer surface is 4% or more and 70% or less, the distance between the facing surface and the inner surface is equal to or less than the width of the groove side wall and 0.5 mm or less, and the groove has a curved shape with the groove openings facing a plurality of the through holes.

[0006] The tissue formation device for solving the above problems is a tissue formation method in which the tissue formation device is buried in an environment outside the human body where the biological tissue material exists, and a connective tissue body is formed in the tissue formation device. The tissue formation device includes a first partition member having an outer surface in contact with the environment and an inner surface opposite to the outer surface, and a second partition member having a facing surface facing the inner surface. A plurality of through holes penetrating from the outer surface to the inner surface are formed in the first partition member, and a groove having a groove opening on the facing surface sandwiched between groove side walls is formed in the second partition member. The opening dimension of the through hole is 0.02 mm or more and 2.5 mm or less, the depth of the through hole is 0.1 mm or more and 2.0 mm or less, the ratio of the opening of the through hole occupying the unit area of the outer surface is 4% or more and 70% or less, the distance between the facing surface and the inner surface is not more than the width of the groove side wall and is 0.5 mm or less, and the groove has a curved shape with the groove opening facing a plurality of the through holes.

[0007] According to the above configuration, the opening dimension of the through hole is 0.02 mm or more and 2.5 mm or less, and the ratio of the area occupied by the opening of the through hole in the unit area of the outer surface is 4% or more and 70% or less. For this reason, the biological tissue material contained in the biological environment is supplied into the through hole, and the biological tissue material supplied into the through hole recognizes the first partition member as a foreign substance and produces connective tissue. Further, since the depth of the through hole is 0.1 mm or more and 2.0 mm or less, the biological tissue material supplied to the through hole is supplied into the groove, and the biological tissue material supplied into the groove produces connective tissue.

[0008] Here, since the distance between the facing surface of the second partition member and the inner surface of the first partition member is not more than the width of the groove side wall and is 0.5 mm or less, (i) the biological tissue material supplied into the groove is less likely to be supplied between the facing surface and the inner surface. As a result, one groove formed in the second partition member causes the biological tissue material supplied from a plurality of through holes to form (ii) a curved connective tissue body conforming to the groove shape. That is, the biological tissue material is less likely to be supplied between the facing surface and the inner surface, and the length of the connective tissue body increases in the limited gap between the first partition member and the second partition member as much as the groove shape is curved.

[0009] In the above-described tissue forming device, the second partitioning member may be configured to be assembled to the first partitioning member by bringing the opposing surface into contact with the inner surface. According to the above configuration, (i) the biological tissue material supplied into the groove does not pass between the opposing surface and the inner surface. For this reason, a shape conforming to the groove shape is likely to be obtained in the connective tissue body. As a result, the dimensional accuracy of the connective tissue body is enhanced.

[0010] In the above-described tissue forming device, the first partitioning member has a cylindrical shape having an outer cylindrical surface as the outer surface, the second partitioning member has a columnar shape having an outer peripheral surface as the opposing surface and is installed inside the cylinder of the first partitioning member, and the groove may have one spiral shape extending in the axial direction of the outer peripheral surface while rotating in the circumferential direction of the outer peripheral surface, or a mesh shape spreading on the outer peripheral surface.

[0011] In the above-described tissue forming device, the first partitioning member has a flat plate shape, the second partitioning member has a flat plate shape that is stacked on the first partitioning member, and the groove may have a curved shape repeating folds or a logarithmic spiral shape when viewed from a viewpoint facing the opposing surface.

[0012] According to the above configuration, (ii) a spiral connective tissue body, a mesh connective tissue body, a curved connective tissue body repeating folds, or a logarithmic spiral connective tissue body conforming to the groove shape can be obtained. The spiral connective tissue body or the logarithmic spiral connective tissue body facilitates one-dimensional deformation so as to be stretched along the spiral central axis or to have the twist released to become linear. The mesh connective tissue body or the curved connective tissue body repeating folds facilitates two-dimensional deformation in the direction in which the mesh spreads or the direction in which the folds are arranged. Any of the connective tissue bodies can expand the range to which the connective tissue body is applied.

[0013] In the above-described tissue forming device, the second partitioning member may include a side wall member including a groove side wall partitioning the groove and the opposing surface, and a bottom wall member including a groove bottom surface partitioning the groove, and the bottom wall member may be configured to contact the opposing surface with the inner surface and sandwich the side wall member between the first partitioning member and the bottom wall member.

[0014] According to the above configuration, since the second partitioning member includes a side wall member and a bottom wall member that is separate from the side wall member, it is possible to remove the first partitioning member and the bottom wall member from the side wall member so as to open the groove opening and the groove bottom surface. Therefore, when the combined tissue is taken out from the tissue forming device, for example, it is also possible to take out the combined tissue from the groove in which the groove opening and the groove bottom surface are opened. As a result, it becomes easy to take out the combined tissue.

[0015] In the above-described tissue forming device, the through hole is a first through hole, a plurality of second through holes penetrating the bottom wall member and communicating with the groove are formed in the bottom wall member, the opening dimension of the second through hole is 0.02 mm or more and 2.5 mm or less, and the depth of the second through hole may be 0.1 mm or more and 2.0 mm or less.

[0016] According to the above configuration, the biological tissue material is supplied into the groove not only through the through hole facing the groove opening but also through the through hole on the groove bottom surface. Therefore, the formation speed of the combined tissue and the shape accuracy of the combined tissue are increased as the number of sites where the biological tissue material is supplied increases.

Effect of the Invention

[0017] The tissue forming device and the tissue forming method of the present disclosure can efficiently form a combined tissue in an environment with limited size.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

DETAILED DESCRIPTION OF THE INVENTION

[0019] An embodiment of the tissue forming apparatus will be described with reference to FIGS. 1 to 4. [Tissue Forming Apparatus] As shown in FIG. 1, the tissue forming apparatus is an apparatus that is buried in an environment where a biological tissue material is present (hereinafter, also simply referred to as a biological environment) to form a connective tissue body.

[0020] The biological tissue material includes various physiologically active substances present in vivo, such as animal cells, proteins, saccharides such as hyaluronic acid, cell growth factors that promote cell growth and differentiation, and cytokines. Animal cells include somatic stem cells, fibroblasts, smooth muscle cells, ES cells, and iPS cells. Proteins include collagen and elastin. The biological tissue material may be a material derived from a human, a material derived from an animal other than the human body, including mammals such as dogs, cows, pigs, goats, and sheep, birds, fish, and others, and an artificial material equivalent thereto. The biological environment may be inside the human body, or inside the body of an animal other than the human body, including mammals such as dogs, cows, pigs, goats, and sheep, birds, fish, and others. The biological environment may be subcutaneous in the limb, shoulder, back, abdomen, etc., or in the abdominal cavity. The biological environment may be an artificial environment containing the biological tissue material. The connective tissue body may be a parallel fibrous connective tissue body such as a tendon or ligament, or an interwoven fibrous connective tissue body such as a perichondrium.

[0021] The tissue formation device demarcates a groove 24 within the biological environment. The groove 24 is a space for forming a connective tissue body. The tissue formation device includes a first partitioning member 11 and a second partitioning member 21. The first partitioning member 11 is the outer shell among the partitioning walls that demarcate the groove 24. The space demarcated by the first partitioning member 11 within the biological environment may be the space in which the second partitioning member 21 is accommodated. In this case, the second partitioning member 21 may be the inner shell among the partitioning walls that demarcate the groove 24.

[0022] The first partitioning member 11 and the second partitioning member 21 may each independently be a metal member or a resin member. The metal constituting the tissue formation device may be any one selected from the group consisting of stainless steel, titanium, titanium-nickel alloy, and cobalt-chromium alloy. The resin constituting the tissue formation device is a non-degradable resin having biocompatibility with living tissue. The non-degradable resin may be any one selected from the group consisting of polymethylpentene-based resins, polyfluoroethylene-based resins, polypropylene resins, polyethylene resins, silicone resins, and mixed resins of these with other resin components.

[0023] [First partitioning member 11] The first partitioning member 11 has a cylindrical shape. The first partitioning member 11 includes an inner surface 12 and an outer surface 13. The inner surface 12 is the inner cylindrical surface of the first partitioning member 11 and is the surface opposite to the outer surface 13. The outer surface 13 is the outer cylindrical surface of the first partitioning member 11 and contacts the biological environment. Note that the first partitioning member 11 may be cylindrical, elliptical cylindrical, or polygonal cylindrical. The first partitioning member 11 may be cylindrical and extend along one straight line or cylindrical and extend along one curve. When the inner surface 12 is a cylindrical surface, the inner surface 12 has an inner diameter 11R.

[0024] In the first partition member 11, a plurality of first through-holes 14 are formed. The first through-holes 14 penetrate the first partition member 11 from the outer surface 13 to the inner surface 12. The first through-holes 14 supply the biological tissue material from the outer surface 13 toward the inner surface 12. The first through-holes 14 are formed by various hole machining methods such as etching and laser drilling. Note that the opening of the first through-hole 14 on the outer surface 13 and the opening of the first through-hole 14 on the inner surface 12 may be circular, elliptical, polygonal, or irregular in shape. The first through-holes 14 may be formed over the entire outer surface 13 or only on a part of the outer surface 13.

[0025] The first partition member 11 satisfies the dimensions of the following [Condition 1] to [Condition 3]. [Condition 1] The opening dimension 14R of the first through-hole 14 is 0.02 mm or more and 2.5 mm or less. [Condition 2] The depth 11T of the first through-hole 14 is 0.1 mm or more and 2.0 mm or less. [Condition 3] The opening occupancy rate is 4% or more and 70% or less.

[0026] The opening dimension 14R of the first through-hole 14 is the diameter of the circle circumscribing the opening of the first through-hole 14. The circle circumscribing the opening of the first through-hole 14 is the circle having the smallest diameter among the circles circumscribing the opening when viewed from a viewpoint facing the opening of the first through-hole 14 on the outer surface 13.

[0027] The depth 11T of the first through-hole 14 is the average value of the thickness of the portion located around the entire circumference of the first through-hole 14 within the first partition member 11. The opening occupancy rate (%) is the ratio with respect to the unit area of the area occupied by the opening of the first through-hole 14. The unit area is the area of the unit region on the outer surface 13 of the first partition member 11. The area occupied by the opening of the first through-hole 14 is the total area of the openings of all the first through-holes 14 included in the unit region.

[0028] As shown in FIG. 2, when the opening dimension 14R of the first through-hole 14 is 0.02 mm or more, since the minimum dimension of the opening through which the biological tissue material passes is about 0.01 mm, biological tissue materials such as plasma proteins and fibroblasts contained in the biological environment can pass through the first through-hole 14. When the opening dimension 14R of the first through-hole 14 is 0.02 mm or more and 2.5 mm or less, the first partition member 11 can ensure mechanical strength while having the first through-hole 14 through which the biological tissue material can pass.

[0029] When the opening occupancy rate is 4% or more, the biological tissue material contained in the biological environment is easily supplied to the second partition member 21 through the first through-hole 14. When the opening occupancy rate is 4% or more and 70% or less, the structure 14P between the mutually adjacent first through-holes 14 is recognized as a foreign substance by the biological tissue material. Fibroblasts that recognize the structure 14P as a foreign substance are promoted to produce collagen at the opening edge of the first through-hole 14 on the inner surface 12 and the like.

[0030] When the depth 11T of the first through-hole 14 is 2.0 mm or less, the biological tissue material entering the first through-hole 14 from the outer surface 13 is easily supplied to the inner surface 12. When the depth 11T of the first through-hole 14 is 0.1 mm or more and 2.0 mm or less, the first partition member 11 can ensure mechanical strength while having the thickness for the biological tissue material to reach the inner surface 12.

[0031] [Second partition member 21] Returning to FIG. 1, the second partition member 21 has a columnar shape that is installed inside the first partition member 11. The second partition member 21 includes a first opposing surface 22 and a groove side wall 23. The first opposing surface 22 is the outer peripheral surface of the second partition member 21 and faces the inner surface 12 of the first partition member 11. The first opposing surface 22 constitutes the top surface of the groove side wall 23. The first opposing surface 22 has a shape conforming to the inner surface 12 of the first partition member 11. When the inner surface 12 is a cylindrical surface, the first opposing surface 22 is a cylindrical surface following the inner surface 12. When the inner surface 12 is an elliptical cylindrical surface, the first opposing surface 22 is a polygonal cylindrical surface following the inner surface 12. When the first opposing surface 22 is a cylindrical surface, the first opposing surface 22 has an outer diameter 21R.

[0032] As shown in FIG. 2, a groove 24 is formed in the second partition member 21. The groove 24 is recessed from the first opposing surface 22 toward the inside of the second partition member 21. The groove 24 has a curved shape with groove openings 24A facing a plurality of first through holes 14. The groove 24 has a groove opening 24A on the first opposing surface 22 and is sandwiched by groove side walls 23. The groove opening 24A communicates with a plurality of first through holes 14. Among the grooves 24 communicating with the first through holes 14, after the adsorption of plasma proteins, they are filled with collagen produced by fibroblasts adsorbed to the plasma proteins.

[0033] The groove side walls 23 may be ridges having the first opposing surface 22 as the top surface. The ridge may be a single male thread continuously spiraling along the first opposing surface 22. When the groove side wall 23 is a single male thread, one groove 24 has a spiral shape extending in the axial direction of the first opposing surface 22 while rotating in the circumferential direction of the first opposing surface 22. Note that the ridge may have a single closed annular shape continuous in the circumferential direction of the first opposing surface 22. The second partition member 21 may have two or more ridges having a closed annular shape arranged in parallel in the axial direction. When the groove side walls 23 having a closed annular shape are arranged in the axial direction of the first opposing surface 22, the groove 24 has a single annular shape continuous in the circumferential direction of the first opposing surface 22. Further, the ridge may have a single linear shape continuous in the axial direction of the first opposing surface 22. The second partition member 21 may have two or more ridges having a linear shape arranged in parallel in the circumferential direction. When the groove side walls 23 having a linear shape are arranged in the circumferential direction of the first opposing surface 22, the groove 24 has a linear shape continuous in the axial direction of the first opposing surface 22.

[0034] The groove side walls 23 may also be a plurality of protrusions 23A scattered with the first opposing surface 22 as the top surface. As shown in FIG. 3, the protrusion 23A may have a quadrangular prism shape, or as shown in FIG. 4, it may have a triangular prism shape. The protrusion 23A may have a conical shape or a hemispherical shape. The groove 24 may have a mesh shape. The mesh shape is a shape in which gaps between adjacent protrusions 23A are connected in a plurality of intersecting directions. The groove 24 may have a mesh shape spreading over the entire first opposing surface 22, or may have a mesh shape spreading only over a part of the first opposing surface 22. The groove 24 may be a combination of a linear shape and a mesh shape.

[0035] The depth 24D of the groove 24 may be 0.5 mm or more and 5 mm or less. When the depth 24D of the groove 24 is 0.5 mm or more, a dense connective tissue body can be easily obtained over the entire groove 24. When the depth 24D of the groove 24 is 5 mm or less, a portion that cannot be buried in the connective tissue body is less likely to remain in the groove 24.

[0036] The gap length 23w, which is the width of the groove side wall 23, is the maximum thickness of the groove side wall 23 in a direction orthogonal to the extending direction of the groove 24, and may be 0.5 mm or more and 5 mm or less. When the gap length 23w is 0.5 mm or more, the mechanical strength of the groove side wall 23 can be easily obtained. When the gap length 23w is 5 mm or less, the size of the connective tissue body formed per unit area of the first facing surface 22 can be easily obtained. The ratio of the depth 24D to the groove width of the groove 24 is the aspect ratio of the groove 24. The groove pitch 24W, which is the pitch at which the grooves 24 are arranged, may be sized to make the aspect ratio of the grooves 24 0.5 or more and 2 or less. The aspect ratio of the groove 24 is appropriately selected according to the cross-sectional shape required for the linear connective tissue body.

[0037] The second partition member 21 satisfies the following [Condition 4]. The second partition member 21 may satisfy the following [Condition 5]. [Condition 4] The gap width, which is the distance between the first facing surface 22 and the inner surface 12, is 0.5 mm or less and is less than or equal to the gap length 23w. [Condition 5] The compressive strength of the first partition member 11 is higher than the compressive strength of the second partition member 21.

[0038] The gap width is the depthwise distance in the first through-hole 14 in the gap between the first facing surface 22 and the inner surface 12. When the gap width is 0.5 mm or less, even if biological tissue materials such as plasma proteins, somatic stem cells, and fibroblasts contained in the biological environment are supplied to the groove 24 wider than the first through-hole 14 after passing through the first through-hole 14, they are difficult to be supplied between the narrow first facing surface 22 and the inner surface 12 like the first through-hole 14. In addition, fibroblasts that recognize the first facing surface 22 as a foreign object are promoted to produce collagen at the edge of the first facing surface 22 and the like, making it even more difficult to supply biological tissue materials between the first facing surface 22 and the inner surface 12. And when the gap width is equal to or less than the gap length 23w and 0.5 mm or less, even if the biological tissue material reaches a part between the first facing surface 22 and the inner surface 12, it is difficult for the biological tissue material to reach the whole between the first facing surface 22 and the inner surface 12. From the viewpoint that the biological tissue material is difficult to be supplied between the first facing surface 22 and the inner surface 12, the gap width is preferably smaller than the opening dimension 14R, more preferably less than 0.05 mm, and even more preferably 0.01 mm or less. When the first facing surface 22 contacts the inner surface 12, the biological tissue materials contained in the biological environment do not pass between the first facing surface 22 and the inner surface 12.

[0039] Therefore, one groove 24 formed in the second partitioning member 21 causes the biological tissue materials supplied from the plurality of first through-holes 14 to form a curved connective tissue body conforming to the groove shape. That is, the biological tissue material is difficult to be supplied between the first facing surface 22 and the inner surface 12, and the length of the connective tissue body becomes larger in the limited gap between the first partitioning member 11 and the second partitioning member 21 as much as the groove shape is curved. From the viewpoint that the connective tissue body is difficult to be formed between the first facing surface 22 and the inner surface 12 and a curved connective tissue body conforming to the groove shape is easily formed, the gap length 23w is preferably large, and preferably larger than the depth 11T of the first through-hole 14.

[0040] In addition, the formation of the connective tissue body in the tissue body forming device may occur competitively between the outer surface 13 of the first partition member 11 and the inside of the groove 24. Even if the structure has mutually equal opening occupation ratios, when the number of the first through holes 14 is small and the size of the openings is large, due to the excessively large gap length 23w, the outer surface 13 of the first partition member 11 is likely to be covered with the collagen film. As a result, before the inside of the groove 24 is filled with the connective tissue body, the openings of the first through holes 14 are likely to be closed with the collagen film. Alternatively, it is difficult for plasma proteins, somatic stem cells, and fibroblasts to be supplied into the first through holes 14. On the other hand, when the number of the first through holes 14 is large and the size of the openings of the first through holes 14 is moderately small, the outer surface 13 of the first partition member 11 is less likely to be covered with the collagen film by the amount of the small gap length 23w. And when the first partition member 11 and the second partition member 21 satisfy [Condition 1] to [Condition 4], with the promotion of the formation of the connective tissue body, the production of collagen by fibroblasts also accelerates. As a result, the blockage of the openings is suppressed before the completion of the formation of the connective tissue body, and thereby the groove 24 is likely to be filled with the connective tissue body.

[0041] The compressive strength of the first partition member 11 and the compressive strength of the second partition member 21 are values measured in accordance with ASTM D695 (Standard Test Method for Compressive Properties of Rigid Plastics). When the compressive strength of the first partition member 11 is higher than the compressive strength of the second partition member 21, it also becomes easy to bring the first opposing surface 22 into contact with the inner surface 12 to make the gap width 0.5 mm or less.

[0042] When the compressive strength of the first partition member 11 is higher than that of the second partition member 21, the second partition member 21 with relatively low compressive strength provides a soft surface to the biological tissue material. The soft surface aligns the longitudinal direction of the collagen fibers with the collagen fibers so that the collagen fibers are stabilized on the surface. That is, the soft inner surface of the groove 24 aligns the longitudinal direction of the collagen fibers in the extending direction of the groove 24, making it easy for the collagen fibers to extend in the extending direction of the groove 24 and promoting the growth of a dense connective tissue body. As a result, when the compressive strength of the second partition member 21 is higher than that of the first partition member 11, densification of the connective tissue body filling the groove 24 is achieved compared to the connective tissue body formed on the outer surface 13 or the like.

[0043] [Method for forming connective tissue body] A method for forming a connective tissue body using a tissue body forming device will be described. First, the tissue body forming device is placed in a biological environment. The biological environment may be inside the human body or inside a living body of an animal other than the human body, including mammals such as dogs, cows, pigs, goats, sheep, birds, fish, and others. The biological environment may be under the skin of the extremities, shoulders, back, abdomen, etc., or in the abdominal cavity. The biological environment may also be an artificial environment containing biological tissue material. When the tissue body forming device is implanted in the living body, first, a minimal incision is made in the living body under sufficient anesthesia. Then, after the tissue body forming device is implanted, the wound is sutured.

[0044] In the tissue body forming device placed in an environment containing biological tissue material, plasma proteins adsorb on the outer surface 13 of the first partition member 11, and fibroblasts adsorb on the plasma proteins. Next, the biological tissue material enters the groove 24 through the first through-hole 14. At this time, plasma proteins adsorb on the inner surface of the first through-hole 14 and the inner surface 12 of the first partition member 11, and fibroblasts adsorb on the plasma proteins. Then, a connective tissue body is formed in the groove 24 from the biological tissue material that has entered the groove 24.

[0045] Here, the groove 24 that satisfies [Condition 5] provides a soft groove inner surface to the biological tissue material. The groove 24 that provides a hard groove inner surface easily fixes the collagen fibers that reach the hard surface to the groove inner surface regardless of the longitudinal direction of the collagen fibers. In contrast, the soft groove inner surface aligns the longitudinal direction of the collagen fibers with the collagen fibers so that the collagen fibers are stabilized on the groove inner surface. That is, the soft groove inner surface of the groove 24 promotes the growth of dense collagen fibers so that the longitudinal direction of the collagen fibers follows the extending direction of the groove 24.

[0046] Next, the tissue formation device implanted in the biological environment is taken out of that environment after a predetermined implantation period, which is the period during which the connective tissue is formed, has elapsed. When taking out the tissue formation device from the biological environment, first, a minimal incision is made on the living body under sufficient anesthesia. Then, after the tissue formation device is taken out, the wound is sutured. The connective tissue formed using the tissue formation device has a linear shape following the shape of the groove 24. The width and height of the connective tissue correspond to the gap length 23w and the depth 24D of the groove 24.

[0047] In addition, when the connective tissue is used for xenotransplantation, in order to suppress the rejection reaction after transplantation, it is preferable that the connective tissue be subjected to immunogenicity removal treatments such as decellularization treatment, dehydration treatment, and fixation treatment. The decellularization treatment is, for example, a treatment in which the extracellular matrix is eluted and washed by ultrasonic treatment, surfactant treatment, enzyme treatment such as collagenase, and the like. The dehydration treatment is a treatment in which the connective tissue is washed with a water-soluble organic solvent such as methanol, ethanol, or isopropyl alcohol. The fixation treatment is a treatment in which the connective tissue is immersed in an aldehyde compound such as glutaraldehyde or formaldehyde.

[0048] [Test Example] A plurality of tissue forming devices having the following materials and various dimensions were prepared using the first partition member 11 and the second partition member 21 having the shapes shown in FIG. 1. At this time, the gap width, the gap length 23w, the depth 24D of the groove 24, and the groove pitch 24W were changed within the following ranges. Specifically, the combination of the interval width and the gap length 23w is denoted as (gap width, gap length 23w), and tissue forming devices having the following gap dimensions of Test Examples 1 to 9 were prepared. Then, using the inside of a dog's body as the environment in which the biological tissue material exists, it was visually confirmed whether a curved connective tissue body conforming to the groove shape could be obtained. As a result, it was confirmed that a curved connective tissue body following the shape of the groove 24 could be obtained by the tissue forming devices of Test Examples 1 to 3. Also, it was confirmed that, similar to Test Examples 1 to 3, a curved connective tissue body following the shape of the groove 24 could be obtained by the tissue forming devices of Test Examples 5, 6, 8, and 9. On the other hand, it was confirmed that the connective tissue bodies formed by the tissue forming devices of Test Examples 4 and 7 had a planar shape in which the curved lines following the shape of the groove 24 were connected in the gap between the first opposing surface 22 and the inner surface 12.

[0049] <Materials and various dimensions> · Material of the first partition member 11: Stainless steel · Material of the second partition member 21: Polyfluoroethylene resin · Opening dimension 14R of the first through hole 14: 0.1 mm · Depth of the first through hole 14: 1 mm · Opening occupancy rate: 50% · Gap width: 0.1 mm or more and 1.0 mm or less · Gap length 23w: 0.3 mm or more and 3.0 mm or less · Depth 24D of the groove 24: 2 mm · Groove pitch 24W: 2 mm · Implantation period of the tissue forming device: 4 weeks <Gap dimensions of test examples> · Test Example 1: (0.1 mm, 0.1 mm) · Test Example 2: (0.1 mm, 0.3 mm) · Test Example 3: (0.1 mm, 3.0 mm) · Test Example 4: (0.5 mm, 0.1 mm) · Test Example 5: (0.5 mm, 0.5 mm) · Test Example 6: (0.5 mm, 3.0 mm) · Test Example 7: (1.0 mm, 0.1 mm) · Test Example 8: (1.0 mm, 1.0 mm) · Test Example 9: (1.0 mm, 3.0 mm)

[0050] [Effects of the Embodiment] As described above, the following effects can be obtained. (1) Since the gap width is 23w or less of the gap length and 0.5 mm or less, the biological tissue material supplied into the groove 24 is difficult to be supplied between the first facing surface 22 and the inner surface 12. As a result, one groove 24 forms a curved connective tissue body conforming to the groove shape in the biological tissue material supplied from a plurality of first through holes 14. That is, the biological tissue material is difficult to be supplied between the first facing surface 22 and the inner surface 12, and the length of the connective tissue body increases in the limited gap between the first partition member 11 and the second partition member 21 as much as the groove shape is curved.

[0051] (2) When the second partition member 21 is assembled to the first partition member 11 with the first facing surface 22 contacting the inner surface 12, the biological tissue material supplied into the groove 24 does not pass between the first facing surface 22 and the inner surface 12. For this reason, a shape conforming to the groove shape is easily obtained in the connective tissue body. As a result, the dimensional accuracy of the connective tissue body is improved.

[0052] (3) The spiral connective tissue body facilitates one-dimensional deformation such as being stretched along the spiral central axis or having its twist released to become linear. The mesh-like connective tissue body facilitates two-dimensional deformation such as the direction in which the mesh spreads or the direction in which the folds are arranged. Any of the connective tissue bodies can expand the range of application of the connective tissue body.

[0053] Note that the above-described embodiment can be implemented with the following modifications. [Tissue Forming Apparatus] · As shown in FIG. 5, the tissue forming device may include a flat first partition member 11 and a flat second partition member 21, and the first partition member 11 may be configured to overlap the second partition member 21. At this time, the second partition member 21 may include a flat side wall member 25 and a flat bottom wall member 31, and the side wall member 25 may be configured to overlap the bottom wall member 31. The first partition member 11 and the second partition member 21 may each have a disc shape. The first partition member 11 may have an outer edge that coincides with the outer edge of the second partition member 21, may be larger than the second partition member 21, or may be smaller than the second partition member 21.

[0054] The side wall member 25 includes a first facing surface 22 that faces the inner surface 12 (the lower surface in FIG. 5) of the first partition member 11 and a second facing surface 22R that faces the bottom wall member 31. One groove 24 penetrating from the first facing surface 22 to the second facing surface 22R is formed in the side wall member 25. The one groove 24 has a curved shape with repeated folds when viewed from a viewpoint facing the first facing surface 22. As shown in FIG. 6, the one groove 24 may have a logarithmic spiral shape when viewed from a viewpoint facing the first facing surface 22.

[0055] The bottom wall member 31 includes a groove bottom surface 33 that faces the second facing surface 22R. The groove bottom surface 33 constitutes the bottom surface of the groove 24. The bottom wall member 31 may be configured such that the first facing surface 22 is brought into contact with the inner surface 12 of the first partition member 11, and the side wall member 25 is sandwiched between the first partition member 11 and the bottom wall member 31. The bottom wall member 31 may be configured such that the groove bottom surface 33 is brought into contact with the second facing surface 22R of the side wall member 25, and the side wall member 25 is sandwiched between the first partition member 11 and the bottom wall member 31. The bottom wall member 31 may be configured such that the distances between the inner surface 12 and the first facing surface 22 and between the groove bottom surface 33 and the second facing surface 22R are each 23w or less and 0.5 mm or less, and the side wall member 25 is sandwiched between the first partition member 11 and the bottom wall member 31.

[0056] (4) According to the above modification example, the second partition member 21 includes the side wall member 25 and the bottom wall member 31 which is separate from the side wall member 25. Therefore, it becomes possible to remove the first partition member 11 and the bottom wall member 31 from the side wall member 25 so as to open the groove opening 24A and the groove bottom surface 33. As a result, when the combined tissue body is taken out from the tissue body forming device, for example, it also becomes possible to take out the combined tissue body from the groove 24 in which the groove opening 24A and the groove bottom surface 33 are opened, so that the combined tissue body can be easily taken out.

[0057] (5) The curved combined tissue body with repeated folding facilitates two-dimensional deformation, such as in the direction in which the folds are arranged. Therefore, the range to which the combined tissue body is applied can be expanded. [Bottom wall member 31] · Further, in the above modification example, the bottom wall member 31 may include a plurality of second through holes 34 that penetrate from the groove bottom surface 33 to the outer surface 32 on the side opposite to the groove bottom surface 33. Similar to the first through hole 14, the second through hole 34 satisfies the above [Condition 1] to [Condition 3]. Similar to the first partition member 11, the bottom wall member 31 satisfies the above [Condition 4]. The compression strength of the first partition member 11 and the compression strength of the bottom wall member 31 may be higher than the compression strength of the side wall member 25.

[0058] (6) According to the above modification example, the biological tissue material is supplied into the groove 24 not only through the first through hole 14 facing the groove opening 24A but also through the second through hole 34 on the groove bottom surface 33. Therefore, the formation speed of the combined tissue body and the shape accuracy of the combined tissue body are increased by the amount of the increased supply sites of the biological tissue material.

Explanation of reference numerals

[0059] 10... Tissue body forming device 11... First partition member 12... Inner surface 13... Outer surface 14... First through hole 21... Second partition member 22... Opposing surface 23... Groove side wall 23w... Gap length 24... Groove 24A…Groove opening 24W…Groove pitch 34…Second through-hole

Claims

1. A tissue forming device that forms a connective tissue body in an environment where a biological tissue material exists, a first partition member having an outer surface that contacts the environment and an inner surface opposite to the outer surface, and a second partition member having an opposing surface that faces the inner surface, wherein a plurality of through holes penetrating from the outer surface to the inner surface are formed in the first partition member, a groove having a groove opening on the opposing surface and sandwiched between groove side walls is formed in the second partition member, the opening dimension of the through hole is 0.02 mm or more and 2.5 mm or less, the depth of the through hole is 0.1 mm or more and 2.0 mm or less, the ratio of the opening of the through hole occupying the unit area of the outer surface is 4% or more and 70% or less, the distance between the opposing surface and the inner surface is not more than the width of the groove side wall and is 0.5 mm or less, the groove has a curved shape with the groove opening facing a plurality of the through holes, characterized in that it is a tissue forming device.

2. The second partition member is configured to be assembled to the first partition member by bringing the opposing surface into contact with the inner surface, The tissue forming device according to Claim 1.

3. The first partition member has a cylindrical shape having an outer cylindrical surface as the outer surface, the second partition member has a columnar shape having an outer peripheral surface as the opposing surface and is installed inside the cylinder of the first partition member, the groove has a single spiral shape that extends in the axial direction of the outer peripheral surface while rotating in the circumferential direction of the outer peripheral surface, or has a mesh shape that spreads over the outer peripheral surface, The tissue forming device according to Claim 1.

4. The first partition member has a flat plate shape, the second partition member has a flat plate shape that is stacked on the first partition member, the groove has a curved shape with repeated folds or a logarithmic spiral shape when viewed from a perspective facing the opposing surface, The tissue forming device according to Claim 1.

5. The second partition member includes a side wall member including a groove side wall that partitions the groove and the opposing surface, and a bottom wall member including a groove bottom surface that partitions the groove, the bottom wall member is configured to be sandwiched between the first partition member and the bottom wall member by bringing the opposing surface into contact with the inner surface so as to sandwich the side wall member, The tissue forming device according to Claim 4.

6. The through hole is a first through hole, a plurality of second through holes penetrating the bottom wall member and communicating with the groove are formed in the bottom wall member, the opening dimension of the second through hole is 0.02 mm or more and 2.5 mm or less, The depth of the second through hole is 0.1 mm or more and 2.0 mm or less. The tissue formation device according to claim 5.

7. A tissue formation method of embedding a tissue formation device in an environment outside the human body where a biological tissue material exists and forming a connective tissue body in the tissue formation device, The tissue formation device is a first partition member having an outer surface in contact with the environment and an inner surface opposite to the outer surface, and a second partition member having an opposing surface facing the inner surface, a plurality of through holes penetrating from the outer surface to the inner surface are formed in the first partition member, a groove having a groove opening on the opposing surface sandwiched between groove side walls is formed in the second partition member, the opening dimension of the through hole is 0.02 mm or more and 2.5 mm or less, the depth of the through hole is 0.1 mm or more and 2.0 mm or less, the ratio of the opening of the through hole to the unit area of the outer surface is 4% or more and 70% or less, the distance between the opposing surface and the inner surface is equal to or less than the width of the groove side wall and 0.5 mm or less, the groove has a curved shape with the groove opening facing a plurality of the through holes, characterized in that it is a tissue formation method.

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