Cell retention device placed in the lower limbs

Abstract

To provide a cell placement device which can place a cell that produces a liquid factor in the vicinity of an artery outer side of a lower limb in order to make the liquid factor sufficiently act on an ischemic limb and a therapeutic method using the cell placement device.SOLUTION: A cell placement device which is placed in the body along a blood vessel of a lower limb comprises a tubular body part which has a lumen that can store a cell. The body part is configured so as not to release the cell injected to the lumen. At least a portion of the body part is made of a porous material so as to allow transmission of a liquid factor produced by the cell injected to the lumen. The body part has an opening that can be opened by pressing. The cell placement device is configured such that the opening is opened by pressing on a skin tissue when being placed, and a cell suspension can be injected to the lumen of the body part from the outside of the body through the opening by puncture on the skin tissue.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a cell indwelling device to be placed in the lower limb and a treatment method. [Background technology]

[0002] In recent years, attempts have been made to transplant various cells to repair damaged tissues, etc. One example of repairing damaged tissues, etc. by cell transplantation is CD34-positive cell therapy for severe lower limb diseases. In this treatment, CD34-positive cells are dissolved in physiological saline and injected intramuscularly into several dozen sites on both legs that are in a severe ischemic state (see, for example, Non-Patent Document 1).

[0003] Catheters are used for patients who require long-term administration of infusions and drug solutions, and one example of such a catheter is described as an indwelling catheter that is placed from outside the body into a blood vessel, body fluid duct, or organ inside the body via a skin puncture site and subcutaneous tissue (see, for example, Patent Document 1). Another example of an indwelling device is described as a cell indwelling device that can place cells inside a body cavity in order to allow humoral factors to act sufficiently on tissues (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4906408 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-079480 [Non-patent literature]

[0005] [Non-Patent Document 1] Fujita et al., Circulation Journal Vol.78, February 2014: 490-501 Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention is to provide a cell placement device that can place cells that produce humoral factors near the outside of the arteries in the lower limbs in order to allow humoral factors to act sufficiently on ischemic limbs, and a treatment method using the cell placement device. [Means for solving the problem]

[0007] After extensive research, the inventors discovered that the above objectives could be achieved by employing a device having a tubular main body that can accommodate cells while allowing liquid factors released from the cells to pass through, and thus completed the present invention.

[0008] That is, the present invention relates to the following. (1) A cell placement device that is placed in the body along the blood vessels of the lower limbs, a tubular body having a lumen capable of accommodating cells; the main body is configured not to release the cells injected into the lumen; At least a part of the main body is made of a porous material so as to be permeable to humoral factors produced by cells injected into the lumen; the main body has an opening that can be opened by pressing; The cell retention device is configured so that, when retained, the opening is opened by pressing the skin tissue, and a cell suspension can be injected from outside the body through the opening into the inner cavity of the main body by puncturing the skin tissue. (2) The cell retention device according to (1), wherein the opening is in the form of a slit on the surface of the main body, and the slit opens when pressed. (3) The cell retention device according to (1) or (2), wherein the porous material is expanded polytetrafluoroethylene (ePTFE). (4) The cell retention device according to any one of (1) to (3), wherein the main body has hair-like projections and is movable within the body by repulsive force against pressure from outside the body. (5) A cell retention device according to any one of (1) to (3), wherein at least a portion of the main body is made of a magnetic material and is movable within the body by application of a magnetic force from outside the body. (6) The cell placement device according to any one of (1) to (5), which can be housed in the lumen of an injection needle and can be injected into the body. (7) The cell retention device according to (6), which has guide members made of sutures at both ends of the main body. (8) The cell placement device according to any one of (1) to (7), wherein the blood vessel of the lower limb is the anterior tibial artery, the posterior tibial artery, or the peroneal artery. (9) A method for improving the state of arterial blood circulation in the lower limbs, comprising: providing a cell retention device, wherein the cell retention device has a tubular main body having an inner lumen capable of accommodating cells and is configured so as not to release the accommodated cells from the cell retention device, and wherein at least a portion of the main body is made of a porous material that allows the passage of liquid factors released from the cells; forming a space in which the main body portion is to be placed near the outside of an artery of the lower limb; and placing the main body portion near the outside of an artery in the lower limb; and filling the body portion with a cell suspension. [Effects of the Invention]

[0009] According to the present invention, by employing a cell placement device having a tubular main body that can accommodate cells and allow humoral factors released from the cells to pass through, cells can be easily placed near the outside of an artery in the lower limb, allowing the humoral factors released from the placed cells to act sufficiently on the target ischemic limb. In particular, by employing a tubular device body, it becomes relatively easy to insert the cell placement device near the outside of an artery in the lower limb. Furthermore, particularly when the cell retention device can be housed in the needle lumen, minimally invasive treatment is possible. [Brief explanation of the drawings]

[0010] [Figure 1] 1 shows an overall view of a cell retention device according to a preferred embodiment of the present invention, where (a) shows an opening in the longitudinal direction, and (b) shows an opening in the lateral direction. [Figure 2] FIG. 2 shows (a) a top view, (b) a cross-sectional view, and (c) a longitudinal-sectional view of the cell retention device shown in FIG. 1(b). [Figure 3] 3 shows (a) a perspective view of the end of a tubular body with a slit-shaped opening and a hole in the inner structure of the opening, and (b) a cross-sectional view of the slit-shaped opening, with the arrow indicating the direction of pressure from outside the body. [Figure 4] FIG. 4 shows (a) an example of the structure of a single-layer opening in the main body of a cell retention device according to a preferred embodiment of the present invention, (b) an example of the structure of a two-layer opening, (c) Example 1 of the inner structure of a two-layer opening, and (d) Example 2 of the inner structure of a two-layer opening. [Figure 5] Figure 5 is (a) a schematic diagram of a cell retention device according to a preferred embodiment of the treatment method of the present invention, which has guide members on both the distal and proximal ends of the main body, and an injection needle that houses the cell retention device, and (b) a schematic diagram of the cell retention device according to a preferred embodiment of the treatment method of the present invention after it has been housed in the injection needle. [Figure 6] 6 is a schematic diagram illustrating a preferred embodiment of the treatment method of the present invention. (a) shows the step of inserting a needle into the vicinity of the outside of an artery from outside the body to form a space for placing the cell-retention device of the present invention. (b) shows the step of placing the cell-retention device of the present invention in the formed space while withdrawing it from the needle. (c) shows the state after the cell-retention device of the present invention has been placed near the outside of an artery. [Figure 7] 7 shows examples of movement of the cell retention device according to a preferred embodiment of the treatment method of the present invention, where (a) the main body has trichomes, (b) the main body has a magnetic material, and (c) the main body has a guide member. The thick arrow indicates the direction of movement of the main body. DETAILED DESCRIPTION OF THE INVENTION

[0011] Preferred embodiments of the present invention will now be described in detail with reference to the drawings. First, the cell retention device of the present invention will be described.

[0012] Figure 1 is an overall view of a cell retention device according to a preferred embodiment of the present invention, where (a) shows a case where an opening is provided in the longitudinal direction, and (b) shows a case where an opening is provided in the lateral direction. Figure 2 shows (a) a top view, (b) a transverse cross-sectional view, and (c) a longitudinal cross-sectional view of the cell retention device shown in Figure 1(b). For ease of explanation, in each figure, the side of the cell retention device 1 that is inserted near the outside of the artery is referred to as the distal end, and the opposite side as the proximal end. 1, the cell retention device 1 has a main body 2 and an opening 23. In another embodiment, the cell retention device 1 further has a guide member 3. The cell retention device 1 is used to retain cells near the outside of an artery by retaining the main body 2, which contains a cell composition such as a cell suspension containing cells, near the outside of an artery in a lower limb. This allows humoral factors to be produced in the cells and released from the cells, which act on the ischemic limb, improving blood flow in peripheral arterial disease caused by arteriosclerosis, foot lesions caused by diabetes, and other conditions, and alleviating lower limb ischemia.

[0013] In the present invention, the term "cell suspension" refers to cells suspended in any medium. The cells may be in the form of single cells, or may be connected to each other via an intervening substance. The cells may contain any gene or a viral vector containing any gene. The cells may also be a cell culture. In the present invention, the term "cell culture" refers to a product obtained through a cell culture step, and includes, but is not limited to, spheroids, sheet-shaped cell cultures, and fragments of sheet-shaped cell cultures. In the present invention, the medium for suspending cells includes, but is not limited to, water, physiological saline, culture medium, buffer solution, diluent, cell preservation solution, and swelling bodies such as gel.

[0014] In the present invention, the location where the cell retention device is to be retained may be, for example, a site where damage (wound) exists in a living body or the vicinity thereof. Damage (wound) includes, but is not limited to, damage to or stenosis of a blood vessel. In such cases, the target site in the tissue is in the tissue near the blood vessel, preferably between the blood vessel wall and the surrounding tissue. In one embodiment, the target site in the tissue is the vascular sheath surrounding the vascular tissue. The target site in the tissue may be determined in advance by ultrasound examination, CT examination, or the like before administration. In one embodiment, the subject in whom the cell placement device of the present invention is to be placed has a lower limb disease. Lower limb diseases include any disease that impairs the lower limbs. Examples of such diseases include, but are not limited to, peripheral arterial disease, varicose veins, deep vein thrombosis, and diabetic foot disease. Preferably, the lower limb disease in the present invention is a disease in which blood vessels in the lower limbs are narrowed or blocked, resulting in impaired blood flow in the lower limbs, such as peripheral arterial disease. In the present invention, peripheral arterial disease includes, but is not limited to, arteriosclerosis obliterans, Buerger's disease, collagen disease, and the like, and particularly severe arteriosclerosis obliterans is referred to as critical limb ischemia. As used herein, "near the outside of an artery in the lower limb" refers to a location outside the blood vessels of the lower limb, such as the tissue surrounding the blood vessels of the lower limb (e.g., the anterior tibial artery, the posterior tibial artery, or the peroneal artery) or the vascular sheath (a thin membrane tissue on the surface of a blood vessel).

[0015] The cells contained in the cell suspension of the present invention are not particularly limited as long as they can be administered into tissues, and include, for example, adhesive cells (adherent cells). Adherent cells include, for example, adhesive somatic cells. Examples of somatic cells include myoblasts (e.g., skeletal myoblasts), muscle satellite cells, mesenchymal stem cells (e.g., derived from bone marrow, adipose tissue, peripheral blood, skin, hair roots, muscle tissue, endometrium, placenta, and umbilical cord blood), tissue stem cells such as cardiomyocytes, fibroblasts, and cardiac stem cells, pluripotent stem cells such as embryonic stem cells and iPS (induced pluripotent stem) cells, synovial cells, chondrocytes, epithelial cells (e.g., oral mucosal epithelial cells, retinal pigment epithelial cells, and nasal mucosal epithelial cells), endothelial cells (e.g., vascular endothelial cells), hepatocytes (e.g., hepatic parenchymal cells), pancreatic cells (e.g., pancreatic islet cells), kidney cells, adrenal cells, periodontal ligament cells, gingival cells, periosteal cells, and skin cells. Somatic cells may be differentiated from iPS cells (iPS cell-derived cells), and examples include iPS cell-derived cardiomyocytes, fibroblasts, myoblasts, epithelial cells, endothelial cells, hepatocytes, pancreatic cells, kidney cells, adrenal cells, periodontal ligament cells, gingival cells, periosteal cells, skin cells, synovial cells, and chondrocytes. Cells also include floating cells. Examples of floating cells include T lymphocytes and B lymphocytes. In one embodiment, the cells contained in the cell suspension of the present invention are particularly preferably cells capable of promoting angiogenesis, for example, cells capable of secreting factors that promote angiogenesis, for example, cytokines such as VEGF.

[0016] These cells are not particularly limited and may be derived from any mammal or other organism, such as humans, non-human primates, dogs, cats, pigs, horses, goats, or sheep. These cells are prepared by suspending or suspending them in a liquid in the following forms: individual cells, clumps of cells (spheroids), membranes of cells in sheet-like cell cultures, or fragments of membrane-like cell cultures. A liquid containing cells in such a state is called a cell composition, and it may contain other substances as long as it is applicable to the present invention. Liquids that can be used to suspend or suspend cells are not particularly limited, but are preferably non-toxic to living organisms. For example, various buffer solutions, culture media, and the like can be used singly or in combination. Drugs such as therapeutic agents and anesthetics may also be added to the cell composition as appropriate. Cell compositions may also be prepared by enclosing cells in a carrier (e.g., a bead-shaped carrier) made of polysaccharides such as alginate, allowing humoral factors to be released from the carrier; this is also considered a cell composition. Hereinafter, the term "cells" may refer to a cell suspension or a cell composition.

[0017] Furthermore, humoral factors released by the above-mentioned cells include, for example, cell growth factors, differentiation-inducing factors, hematopoietic factors, and various other cytokines. Examples of these humoral factors include HGF, VEGF, SDF-1, etc. Naturally, humoral factors other than those exemplified above may also be released from the above-mentioned cells, and since these released humoral factors act together on tissues, it goes without saying that the concept of humoral factors in this specification also includes humoral factors other than those exemplified.

[0018] 1 and 2, the cell retention device 1 has a cylindrical main body 2 and an opening 23 provided on the surface of the main body 2. The main body 2 is connectable to a guide member 3 and has a cylindrical shape.

[0019] As shown in Figures 1 and 2, the main body 2 has a tubular overall shape, and a space 21 is formed therein. This shape makes it easy to insert the cell retention device 1 near the outside of an artery. That is, when inserting the cell retention device 1 near the outside of an artery, it is necessary to form a space in the tissue of the lower limb, etc., but this space can be made as small as possible by forming a space of, for example, several centimeters with a syringe needle, and as a result, treatment using the cell retention device 1 can be performed minimally invasively. Furthermore, when the cell retention device 1 is placed near the outside of an artery, it is less likely to interfere with the tissue it comes into contact with.

[0020] Furthermore, the main body 2 is formed so that its distal end 22 and proximal end 24 seal the space 21. More specifically, the distal end 22 and proximal end 24 separate the space 21 from the external space. The space 21 is formed inside the tubular main body 2 and contains the cells 300. Furthermore, the space 21 contains a cell composition containing cells when the cell indwelling device 1 is placed near the outside of the artery.

[0021] Furthermore, openings 23 are provided on the surface of the main body 2 along the lateral or longitudinal direction of the main body 2. The cell composition is configured to be supplied to the space 21 through the openings 23. The openings 23 have a sufficient opening area to accommodate the cells. For example, the cell composition can be injected into the space 21 by puncturing the skin with a syringe needle and passing through the openings.

[0022] The length of the main body 2 is not particularly limited as long as it can pass through the inner diameter of the injection needle and be housed in the injection needle, but it can be, for example, 1 to 30 mm, and preferably 3 to 10 mm. Furthermore, the width (i.e., diameter) of the main body 2 is not particularly limited as long as it can pass through the inner diameter of the injection needle and be housed in the injection needle, but it can be, for example, 30 μm to 500 μm, preferably 100 μm to 200 μm.

[0023] At least a portion of the main body forming the lumen is made of a material that allows humoral factors released from cells to pass through. As a result, when the cell retention device 1 is retained near the outside of an artery, the cells stored in the lumen release humoral factors, which are then released outside the cell retention device 1. The released humoral factors then act on the target site in the artery of the lower limb, for example, an ischemic area. However, the cells are not released outside the cell retention device 1, and are retained near the outside of the artery while being stored in the lumen 21. This prevents the cells from diffusing near the outside of the artery, allowing the humoral factors to reach the target site sufficiently.

[0024] The material constituting at least a portion of such a main body is not particularly limited as long as it allows the passage of the desired humoral factor but does not allow cells to pass through, but for example, materials with pores that allow the passage of humoral factors but not cells can be used, specifically, fiber materials (mesh fabrics) with a specific mesh such as woven fabrics (woven fabrics, knitted fabrics) and nonwoven fabrics, and porous membranes such as semipermeable membranes, which can be used alone or in combination of two or more. In particular, porous membranes made of fluororesins mainly composed of polytetrafluoroethylene (registered trademark) (porous PTFE membranes) are preferably used because they are chemically stable and have excellent heat resistance, chemical resistance, and mechanical strength.

[0025] As shown in FIG. 3(a), the end 22 of the tubular main body is sealed, and the tubular main body can have, for example, a slit-shaped opening in the horizontal axis direction. For example, as shown in FIG. 3(b), the slit 23 can be formed by making an oblique cut in the tubular main body.

[0026] As shown in Figure 4(a), the opening 23 on the surface of the main body has the function of, for example, a valve or slit, and is normally closed, but can be opened by shifting the valve or slit when pressed from above the skin tissue, and is large enough to allow a cell composition to be injected through the opening 23 with an injection needle by puncturing the skin tissue.

[0027] The opening 23 can also be formed from an elastic body. On the other hand, the opening 23 can be penetrated by an injection needle 400 or the like, and therefore, the injection needle 400 can be penetrated through the opening 23 to inject a cell composition containing cells into the space 21. The elastic material that constitutes the opening 23 is not particularly limited, but a material with excellent elasticity is preferable, and for example, silicone rubber, butyl rubber, latex rubber, isoprene rubber, etc. can be used alone or in combination of two or more.

[0028] As shown in Figure 4(b), the opening can be made into a two-layer structure by layering the above-mentioned rubber or gel body on its inside, ensuring strength sufficient to prevent breakage during injection of the cell composition. For example, the strength of the main body can be ensured by layering a rubber or gel body with a hole in the position corresponding to the opening, as shown in Figure 4(c), or a rubber or gel body with fine holes throughout, as shown in Figure 4(d), on the inside (lumen side) of the valve or slit.

[0029] As described above, the main body 2 of the cell retention device 1 has sealed distal end 22 and proximal end 24, and the opening 23 is made of a material that does not allow cells to pass through. Therefore, the cell retention device 1 does not release the stored cells to the outside. Therefore, even if the stored cells are retained in a body cavity for a relatively long period of time, the cells are prevented from diffusing to the outside of the cell retention device 1, and humoral factors can be more reliably delivered to the desired site in the tissue, such as an ischemic site.

[0030] As shown in Fig. 5, the main body portion may have guide members 3 at its distal and proximal ends. For example, as shown in Fig. 5(b), the main body portion 2 is configured so as to be able to fit within the inner diameter of an injection needle 400. This makes it easier to insert the cell retention device 1 near the outside of an artery. The guide member 3 is fixed to the base end of the main body, and can be used when storing the guide member 3 in the lumen of the needle 400 of the injection needle. As shown in Figure 7(c), for example, by fixing the guide member 3 to the tip of the main body, the guide member can be extended and fixed in the space 500 formed inside the body by the needle. The guide member can be made by closing or tying off the distal and proximal ends of a tubular body constructed from a porous material, which can be made, for example, with sutures.

[0031] It goes without saying that the size and other details of each component of the cell retention device 1 described above can be appropriately set by a person skilled in the art according to the condition of the blood vessels of the lower limb to which it is applied, even if not otherwise specified.

[0032] Next, the treatment method of the present invention will be described based on a preferred embodiment. 6 and 7 are schematic diagrams illustrating a preferred embodiment of the treatment method of the present invention. Note that in the related drawings, some parts may be enlarged or reduced in size and shown at different scales from the actual size for the purpose of illustrating the embodiment.

[0033] The treatment method of the present invention is a method for improving the state of arterial blood circulation in the lower limbs, comprising: providing a cell retention device, wherein the cell retention device has a tubular main body having an inner lumen capable of accommodating cells and is configured so as not to release the accommodated cells from the cell retention device, and wherein at least a portion of the main body is made of a porous material that allows the passage of liquid factors released from the cells; a step of forming a space in which the main body portion is to be placed near the outside of the artery of the lower limb (space forming step); a step of placing the main body portion near the outside of the artery of the lower limb (placement step); and The method includes a step of filling the main body with a cell suspension (cell filling step).

[0034] In the following, this embodiment will be described assuming that the cell indwelling device 1 described above is placed near the outside 200 of the artery 100 of a lower limb to treat an ischemic limb.

[0035] First, in the first step, a cell retention device 1 is provided that has a main body 2. As described above, the main body 2 has an inner cavity capable of storing cells, and is configured so as not to release the stored cells from the main body 2. Furthermore, as described above, the tubular main body 2 is made of a material that allows the passage of liquid factors released from cells. The provided cell retention device 1 may be washed and sterilized as appropriate by known methods.

[0036] Next, in the space forming step, a space is formed for placing the cell retention device 1. Specifically, an injection needle is inserted near the outside of a blood vessel in the lower limb to form a space in which the cell retention device can be placed and, if necessary, a space in which the guide member 3 can be placed.

[0037] Next, in the placement step, the main body 2 is placed in a hollow injection needle of a size large enough to accommodate the main body 2, and the needle is inserted through the skin to push out the main body 2, thereby placing the main body 2 near the outside of the artery. The placement step can be performed without connecting the guide member 3 to the main body 2, and after puncturing the body, the space formed in the space formation step can be moved back and forth by pressing the skin tissue from outside the body. As shown in Figure 7(a), when the main body has hair-like protrusions 4, the repulsive force of the protrusions can be used to push the main body in the opposite direction to move it in the desired direction. The hair-like protrusions can be made of resin such as polycarbonate. As shown in Figure 7(b), when at least a portion of the main body is made of magnetic material 5, the space formed in the space forming step can be moved in the desired direction (direction of the arrow) by magnetic force from outside the body.

[0038] 7(c), delivery of the cell retention device 1 may be performed by connecting the main body 2 to the guide member 3, manipulating the guide member 3, inserting it into the body, and then fixing it near the outside of the artery. This facilitates insertion into the lumen of the injection needle, prevents unintended movement of the cell retention device 1 during the retention step, and also makes it easy to retrieve the cell retention device 1 after the retention step.

[0039] Next, in the cell filling step, the cells 300 are filled into the main body part 2, and the main body part 2 is maintained in a state in which it is placed near the outside of the blood vessel, thereby placing the cells 300 near the ischemic tissue. This step is carried out by leaving the cell retention device 1 arranged as described above for a certain period of time, for example, 2 to 60 days, preferably 7 to 21 days.

[0040] In this step, by placing the cell placement device 1, the liquid factors produced and released in the cells 300 are released near the outside of the blood vessel via the main body 2. The released liquid factors are expected to act on the ischemic tissue and treat the ischemic limb.

[0041] Next, in the removal step, the cell retention device 1 is removed from the vicinity of the outside of the artery. In this step, first, an incision is made again as appropriate to expose the guide member 3 on the base end side of the cell retention device 1. Next, the cell retention device 1 is pulled out together with the delivery member 3, and the cell retention device 1 is removed from near the outside of the artery. Finally, the incision is sutured.

[0042] As described above, according to the present invention, by employing a cell retention device having a main body that can accommodate cells while allowing the passage of liquid factors released from the cells, cells can be easily retained in a body cavity, allowing the liquid factors released from the retained cells to act sufficiently on the target tissue. In particular, by employing a tubular device body, it becomes relatively easy to insert the cell placement device near the outside of the artery.

[0043] In particular, the present invention can be used not only with cells used in conventional tissue or cell transplants, but also with cells (or cell-containing grafts) that are not suitable for transplantation but release necessary fluid factors. Furthermore, particularly when the cell retention device can be housed in an injection needle, the puncture area for inserting the cell retention device can be made small, allowing for minimally invasive treatment.

[0044] Although the present invention has been described above with reference to the illustrated embodiment, the present invention is not limited to this. In the present invention, each component can be replaced with any component that can exert a similar function, or any component can be added. [Explanation of symbols]

[0045] 1. Cell placement device 2 Main body 21 Space (lumen) 22 Tip 23 Opening (valve or slit) 24 Proximal end 25 inner layer 3 Guide member 4 trichomes 5 Magnetic materials 100 arteries 200 Near the outside of the artery 300 cells 400 syringe needle 500 Space (inside the body)

Claims

1. A cell placement device to be placed near the outside of an artery, a tubular body having a lumen capable of accommodating cells; the main body is configured not to release the cells injected into the lumen; At least a part of the main body is made of a porous material so as to be permeable to humoral factors produced by cells injected into the lumen; the main body has an opening that can be opened by pressing, The opening is in the form of a slit on the surface of the main body, and the slit opens when pressed. The cell retention device is configured so that when retained, the tubular main body is not exposed to the outside of the body, and an opening is opened by pressing the skin tissue, and a cell suspension can be injected from outside the body through the opening into the inner cavity of the main body by puncturing the skin tissue.

2. The cell retention device according to claim 1 , wherein the porous material is expanded polytetrafluoroethylene (ePTFE).

3. The cell retention device according to claim 1 or 2, wherein the main body portion has hair-like protrusions, is movable within the body by repulsive force against pressure from outside the body, and has spaces in front and behind the main body portion to allow the main body portion to move within the body.

4. The cell retention device according to claim 1 or 2, wherein at least a portion of the main body is made of a magnetic material and is movable within the body by application of a magnetic force from outside the body.

5. The cell retention device according to any one of claims 1 to 4, which can be housed in the lumen of an injection needle and can be injected into the body.

6. The cell retention device according to claim 5 , wherein the main body has guide members made of sutures at both ends thereof.

7. A cell placement device described in any one of claims 1 to 6, wherein the artery is the anterior tibial artery, the posterior tibial artery, or the peroneal artery.

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