Target cell capture filter and target cell capture method

Abstract

Provided is a target cell capture filter, which is a filter for simply, quickly, and efficiently separating and capturing target cells contained in a biological sample such as blood, and the target cell capture filter has an increased capture rate per unit area. The solution is a target cell capture filter, characterized in that it is a target cell capture filter having a capture surface capable of capturing target cells in a liquid, the target cell capture filter has a plurality of incisions, and the incisions enable a part of the capture surface to elastically deform in a direction perpendicular to the capture surface to form a gap. At least a part of the plurality of incisions is a first incision group, and the amount of elastic deformation with respect to the impulse per unit area is equal. The first incision group is a plurality of incisions with different shortest distances from the maximum deformation part of the incision to the outer edge of the capture surface.

Description

Technical Field

[0001] The present invention relates to a target cell capture filter and a target cell capture method, and particularly to a target cell capture filter having a capture surface capable of capturing target cells in a liquid, etc. Background Art

[0002] Selectively extracting target substances (mainly cells, microorganisms, proteins, exosomes, etc.) in a liquid has become a very important subject in life science and biotechnology fields such as medicine, health, and agriculture, and a method for simply, quickly, and efficiently capturing only the target substances is desired.

[0003] The inventors of the present application have so far proposed a target cell capture device (Patent Document 1) for simply, quickly, and efficiently separating and capturing target cells contained in a biological sample such as blood.

[0004] In addition, Patent Document 2 discloses a method of "using a microfluidic chip in which avidin is immobilized in a cell capture path", "pre-adding a nucleic acid aptamer modified with biotin to a sample and incubating", and "filling the incubated mixed solution into the microfluidic chip, so that the target cancer cells in the mixed solution bind to avidin via biotin to achieve separation of the target cancer cells".

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-83265

[0008] Patent Document 2: Specification of Chinese Patent Application Publication No. 103087899 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] However, although the existing capture methods (Patent Document 1 and Patent Document 2) can achieve capture of target cells, there is a problem that the capture rate per unit area is not increased.

[0011] Therefore, an object of the present invention is to provide a target cell capture filter with an increased capture rate per unit area.

[0012] Means for Solving the Problems

[0013] A first aspect of the invention of the present application is a target cell capture filter, which is characterized in that it is a target cell capture filter having a capture surface capable of capturing target cells in a liquid. The target cell capture filter has a plurality of incisions, and these incisions enable a part of the capture surface to elastically deform in a direction perpendicular to the capture surface to form a gap. At least a part of the plurality of incisions is a first incision group, and the amount of elastic deformation with respect to the impulse per unit area is equal. The first incision group is a plurality of incisions having different shortest distances from the maximum deformation part of the incision to the outer edge of the capture surface.

[0014] A second aspect of the invention of the present application is the target cell capture filter of the first aspect. In this target cell capture filter, the plurality of incisions belonging to the first incision group are arranged in a pattern shape, and the pattern shape is formed in a nested box shape, and the nested box-shaped pattern shape is arranged more closely from the inside to the outside.

[0015] A third aspect of the invention of the present application is the target cell capture filter of the second aspect. This target cell capture filter has a plurality of the nested box-shaped pattern shapes.

[0016] A fourth aspect of the invention of the present application is the target cell capture filter of any one of the first to third aspects. In this target cell capture filter, the lengths of the line segments of the plurality of incisions belonging to the first incision group are equal.

[0017] A fifth aspect of the invention of the present application is the target cell capture filter of any one of the first to fourth aspects. In this target cell capture filter, the plurality of incisions belonging to the first incision group are arranged in a concentric circle pattern.

[0018] A sixth aspect of the invention of the present application is the target cell capture filter of the fifth aspect. In this target cell capture filter, the concentric circles sequentially have, in ascending order of radius: a first circle having a first radius, a second circle having a second radius, and a third circle having a third radius. The difference in length between the second radius and the first radius is greater than the difference in length between the third radius and the second radius.

[0019] A seventh aspect of the invention of the present application is a method for capturing target cells using a target cell capture filter having a capture surface capable of capturing target cells in a liquid. The method for capturing target cells includes a target cell capture step of capturing the target cells in the liquid by the target cell capture filter. The target cell capture filter has a plurality of incisions that allow a part of the capture surface to elastically deform in a direction perpendicular to the capture surface to form a gap. At least a part of the plurality of incisions is a first incision group, and the amount of elastic deformation per unit area of impulse is equal. The first incision group is a plurality of incisions having different shortest distances from the maximum deformation part of the incision to the outer edge of the capture surface.

[0020] Effects of the Invention

[0021] According to the first aspect of the present invention, by making the amount of deformation of the gap equal when the target cell capture filter elastically deforms, the liquid uniformly passes through the entire surface of the target cell capture filter, and capture using the entire surface of the filter can be achieved. Therefore, the capture rate per unit area of the filter can be improved.

[0022] In addition, according to the second, third, or fifth aspect of the present invention, by making the stiffness of the target cell capture filter uniform, the amount of deformation when elastically deformed becomes equal compared to existing filters, making it easier to capture using the entire surface of the filter.

[0023] The inventors of the present invention found that the capture amount of the outer part of the existing target cell capture filter is extremely small, and considering that this adverse condition stems from the structural stiffness imbalance of the filter and the problem of the gap when elastically deformed, the present invention was conceived.

[0024] Furthermore, according to the fourth aspect of the present invention, by making the lengths of the line segments of the incisions equal, the amount of deformation of the gap when elastically deformed becomes equal, thus making it easier to capture using the entire surface of the filter.

[0025] According to the fifth aspect of the present invention, by forming concentric incisions, gaps can be arranged without bias on the entire surface of the target cell capture filter, and the target cell capture filter is suitable for a generally used conical container. Brief Description of the Drawings

[0026] Figure 1 It is a diagram showing an example of the incisions of the target cell capture filter.

[0027] Figure 2 It is a histogram showing the measurement results of the capture density of target cells based on the differences in the incisions of the filter. Detailed Description of the Invention

[0028] Hereinafter, embodiments of the invention of the present application will be described with reference to the accompanying drawings. In addition, the invention of the present application is not limited to the following embodiments.

[0029] Embodiment

[0030] The present invention mainly relates to a three-dimensional filter for size-selective and affinity-specific classification of a target substance present in a liquid and a method for capturing target cells using the three-dimensional filter, and particularly relates to a three-dimensional filter for effectively capturing target cells present in a liquid, etc.

[0031] Figure 1 (A) is a diagram illustrating a target cell capture filter 1 and a target cell capture filter 21 according to this embodiment. The target cell capture filter 1 and the target cell capture filter 21 are in a plate shape except when in use. In addition, the target cell capture filter 1 and the target cell capture filter 21 are each an example of the "target cell capture filter" in the claims of the present application.

[0032] Figure 1 The target cell capture filter 1 (hereinafter referred to as "composite 3D filter 1") shown in (A) has notches 3 (an example of the "notch" in the claims of the present application) in the shape of different concentric circles (an example of the "graphical shape" and "concentric circles" in the claims of the present application) within one surface (an example of the "capture surface" in the claims of the present application). In addition, Figure 1 The target cell capture filter 21 in (B) (hereinafter referred to as "equispaced filter 21") has a notch 3 in the shape of one concentric circle (an example of the "graphical shape" and "concentric circles" in the claims of the present application). By having the notch 3, a part of the surface can elastically deform in a direction perpendicular to the surface to form a gap. From the center through the gap concentrically towards the outside, the interval for forming the gap becomes narrower within the surface, so that the width of the gap when elastically deformed by hydrodynamic force becomes equispaced.

[0033] Figure 2 It is a histogram showing the measurement results of the capture density of target cells based on the differences in the notches of the target cell capture filter. Here, the measurement will be described. It is considered to pre-modify the target cells with nucleic acid aptamers, and the binding to the filter utilizes biotin-avidin binding. Specifically, a nucleic acid aptamer modified at the end with biotin is introduced into a sample solution containing target cells, and the target cells are bound to the nucleic acid aptamer, thereby modifying the filter with avidin. Then, the sample solution is introduced into the filter, thereby forming a structure for capturing target cells using biotin-avidin binding. As Figure 2As shown, compared with the existing filter 51, the capture density of target cells in the equally-spaced filter 21 of this embodiment is increased to more than three times. Furthermore, compared with the existing filter 51, it can be seen that in the composite 3D filter 1, the capture density of target cells is increased to about 20 times.

[0034] The target cell capture filters 1 and 21 have a plurality of incisions 3 that elastically deform to form gaps, and at least a part of the plurality of incisions 3 has the following characteristics. That is, it has

[0035] (1) a plurality of incisions,

[0036] (2) the shortest distances from the maximum deformation parts of the respective incisions to the outer edge 5 of the target cell capture filter are different from each other

[0037] such characteristics. Hereinafter, the plurality of incisions having such characteristics are referred to as "the first incision group" (an example of "the first incision group" in the claims of this application).

[0038] In addition, the first incision group also has the characteristic that the amount of elastic deformation with respect to the impulse per unit area in the central part 7, which is the area including the center of the filter, is equal to the amount of elastic deformation with respect to the impulse per unit area in the outer edge part 9, which is the area in contact with the outer edge of the filter.

[0039] Here, the amount of deformation can be represented by the area of the gap and can be approximately obtained by the product of the length of the gap and the distance where the deformation has occurred.

[0040] In addition, for the target cell capture filter 21, the lengths of the incisions 3 are prepared to be equal. Compared with the existing filter 51 in which the length of the outermost concentric circular incision is longer, the stiffness of the filter is increased, so that clogging before deformation into a three-dimensional shape is likely to occur, and the object to be captured is likely to stay on the target cell capture filter 21. Considering this also relates to the improvement of the capture rate of target cells.

[0041] On the other hand, in the target cell capture filter 1, the shorter the arc of the incision, the shorter the length of the incision.

[0042] Since the cell capture filter of this embodiment elastically deforms to the same extent in the central part and the outer edge part, the liquid can easily pass through the entire surface of the filter uniformly. Therefore, the amount of the object to be captured in contact with the filter per unit area is the same in the central part and the outer edge part, and the capture rate of the object to be captured can be greatly improved compared with the existing filter.

[0043] In addition, in the present embodiment, the target cell capture filter is provided in a plate shape, but any shape having a capture surface is acceptable, and it may also be a shape other than a plate shape, such as a film shape. Additionally, the capture surface is not limited to a flat surface and may also be a curved surface.

[0044] Symbol Explanation

[0045] 1: Target cell capture filter, 3: Notch, 5: Outer edge, 7: Central part, 9: Outer edge part, 21: Target cell capture filter.

Claims

1. A target cell capture filter, characterized in that, it is a target cell capture filter having a capture surface capable of capturing target cells in a liquid, the target cell capture filter has a plurality of incisions, and these incisions enable a part of the capture surface to elastically deform in a direction perpendicular to the capture surface to form a gap, at least a part of the plurality of incisions is a first incision group, and the amount of deformation of the elastic deformation with respect to the impulse per unit area is equal, the first incision group is a plurality of incisions with different shortest distances from the maximum deformation part of the incision to the outer edge of the capture surface, the plurality of incisions belonging to the first incision group are arranged in a manner that respectively forms circles, the circles at least successively have in the order of increasing radius: a first circle having a first radius, a second circle having a second radius, and a third circle having a third radius, the difference in length between the second radius and the first radius is greater than the difference in length between the third radius and the second radius, the first circle, the second circle, and the third circle are a set of concentric circles sharing one center, the lengths of the plurality of incisions belonging to the first incision group are equal.

2. A target cell capture filter, characterized in that, it is a target cell capture filter having a capture surface capable of capturing target cells in a liquid, the target cell capture filter has a plurality of incisions, and these incisions enable a part of the capture surface to elastically deform in a direction perpendicular to the capture surface to form a gap, at least a part of the plurality of incisions is a first incision group, and the amount of deformation of the elastic deformation with respect to the impulse per unit area is equal, the first incision group is a plurality of incisions with different shortest distances from the maximum deformation part of the incision to the outer edge of the capture surface, the plurality of incisions belonging to the first incision group are arranged in a manner that forms a graphic shape, and the graphic shape is formed in a nested box shape, the target cell capture filter has a plurality of graphic shapes arranged in the nested box shape, the plurality of graphic shapes are arranged axially symmetric with respect to a straight line connecting the center of the filter and the center of any one graphic shape.

3. The target cell capture filter according to claim 2, wherein, the plurality of incisions belonging to the first incision group are arranged in a manner that respectively forms circles.

4. The target cell capture filter according to claim 2 or 3, wherein, each of the graphic shapes is a set of concentric circles having a plurality of circles with different radii and sharing one center.

5. A target cell capture method, characterized in that, it is a target cell capture method using a target cell capture filter having a capture surface capable of capturing target cells in a liquid, including a target cell capture step of capturing the target cells in the liquid by the target cell capture filter, the target cell capture filter has a plurality of incisions, and these incisions enable a part of the capture surface to elastically deform in a direction perpendicular to the capture surface to form a gap, at least a part of the plurality of incisions is a first incision group, and the amount of deformation of the elastic deformation with respect to the impulse per unit area is equal, The first incision group is a plurality of incisions with different shortest distances from the maximum deformation part of the incision to the outer edge of the target cell capture filter. The plurality of incisions belonging to the first incision group are arranged in a manner that respectively forms a circle. The circle has at least, in the order of increasing radius: a first circle with a first radius, a second circle with a second radius, and a third circle with a third radius. The difference in length between the second radius and the first radius is greater than the difference in length between the third radius and the second radius. The first circle, the second circle, and the third circle are a set of concentric circles sharing one center. The lengths of the plurality of incisions belonging to the first incision group are equal.

6. A method for capturing target cells Characterized in that It is a method for capturing target cells using a target cell capture filter having a capture surface capable of capturing target cells in a liquid, including a target cell capture step of capturing the target cells by the target cell capture filter in the liquid. The target cell capture filter has a plurality of incisions, and these incisions enable a part of the capture surface to elastically deform in a direction perpendicular to the capture surface to form a gap. At least a part of the plurality of incisions is the first incision group, and the amount of deformation of the elastic deformation with respect to the impulse per unit area is equal. The first incision group is a plurality of incisions with different shortest distances from the maximum deformation part of the incision to the outer edge of the target cell capture filter. The plurality of incisions belonging to the first incision group are arranged in a manner that forms a graphic shape, and the graphic shape is formed in a nested box shape. The target cell capture filter has a plurality of graphic shapes configured in the nested box shape. The plurality of graphic shapes are configured to be axisymmetric with respect to a straight line connecting the center of the filter and the center of any one graphic shape.

7. The target cell capture filter according to claim 6 Wherein The plurality of incisions belonging to the first incision group are arranged in a manner that respectively forms a circle.

8. The method for capturing target cells according to claim 6 or 7 Wherein Each of the graphic shapes is a set of concentric circles having a plurality of different radii and sharing one center.

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