DE112024000459T5 - Nerve cell culture chip - Google Patents

Abstract

Providing a nerve cell culture chip that can increase the probability that neurites grown from cultured nerve cells are introduced into a microchannel. A nerve cell culture chip comprises: a bottom plate, a main body part firmly in contact with an upper surface of the bottom plate, a first recess and a second recess formed at positions spaced apart in a first direction parallel to a main surface of the main body part to penetrate the main body part and expose the bottom plate, a microchannel connecting the first recess to the second recess in the first direction in a region overlapping the main body part in a second direction orthogonal to the main surface of the main body part, and a first groove formed in a part of a bottom part of the first recess and connected to an end portion of the microchannel in the first direction.

Description

TECHNICAL FIELD

The present invention relates to a microfluidic device (nerve cell culture chip) for cultivating nerve cells.

TECHNICAL BACKGROUND

Drug discovery research includes a phase for evaluating toxicity and safety, as well as a phase for confirming the efficacy of a medicinal agent. Impairment of peripheral nerves through drug administration is undesirable, as such impairment has a major impact on a patient's quality of life (QOL). Therefore, it is important in drug research to understand the effects on nerves, such as peripheral nerves (neurotoxicity) in advance.

A conventional method for assessing neurotoxicity is an observational test, in which a reflex movement is observed in a procedure involving experimental animals. In addition, there is an electrophysiological measurement method using a multi-electrode array in a culture test with cultured cells.

However, the method using animals is less reliable when applied to the human body, as the animals are a different species than the human body. Furthermore, the cell electrophysiology method requires a very high level of expertise for measurement and analysis. Another problem is that the method cannot be used for a large number of tests because the measuring equipment is expensive.

Therefore, in recent years, a method has been proposed in which nerve cells are cultured in a culture chip using a microfluidic device, and neurites are formed from the nerve cells to observe the neurites, thereby evaluating drug stimulation and its response. Microfluidic devices that can be used for such an application include those disclosed in Patent Documents 1 and 2 below.

STATE OF THE ART DOCUMENT

PATENT DOCUMENTS

• Patent Document 1: WO 2021/015213
• Patent Document 2: JP-T-2012-504949

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

To observe neurites using the method described above, the neurites must be positioned in a microchannel provided in the microfluidic device. However, even when the nerve cells are cultured in the microfluidic device, whether the grown neurites are introduced into the microchannel or not is a stochastic event, because the direction in which the nerve cells form neurites is random. Therefore, many nerve cells must be cultured to obtain sufficient data for analysis. However, since nerve cells are generally expensive, it is preferable to observe the neurites while reducing the number of nerve cells to be cultured as much as possible.

In view of the above-mentioned problems, an object of the present invention is to provide a nerve cell culture chip that can increase the probability that the neurites grown from the cultured nerve cells are introduced into a microchannel.

MEANS TO SOLVE THE PROBLEMS

A nerve cell culture chip according to the present invention comprises: a bottom plate, a main body part firmly in contact with an upper surface of the bottom plate, a first recess and a second recess formed at positions spaced apart in a first direction parallel to a main surface of the main body part to penetrate the main body part and expose the bottom plate, a microchannel connecting the first recess to the second recess in the first direction in a region overlapping the main body part in a second direction orthogonal to the main surface of the main body part, and a first groove formed in a part of a bottom part of the first recess and connected to an end portion of the microchannel in the first direction.

According to the above configuration, when the nerve cells are seeded and cultured in the first well, the neurites grown from the nerve cells grow easily along the first groove provided in the lower part of the first well. The microchannel is a channel connecting the first well with the second well in the first direction, and the first groove is connected to an end portion of the microchannel in the first direction. As a result, the grown neurites are easily inserted into the microchannel along the first groove.

The first groove preferably has a size that allows the neurites to extend within it. The width of the first groove is preferably 5 µm to 150 µm, more preferably 10 µm to 100 µm, and most preferably 15 µm to 50 µm.

Likewise, the depth of the first groove is preferably 3 µm to 80 µm, more preferably 3 µm to 60 µm and particularly preferably 3 µm to 20 µm.

The first groove may be configured to extend in the first direction.

The nerve cell culture chip described above may further comprise a second groove connecting a main bottom surface, which is a region of the bottom part of the first recess in which the first groove is not formed, with an end portion of the first groove in the first direction, wherein the second groove connects the main bottom surface and the end portion of the first groove to form a downward slope from the main bottom surface toward the first groove at a position of an outer peripheral part in the first recess.

According to the above configuration, the neurites extending along the first groove can be more easily inserted into the microchannel through the second groove.

The bottom part of the first recess may include a main bottom surface, which is a region where the first groove is not formed, and an outer peripheral part having a height greater than a height of the main bottom surface, and the first groove may extend from the microchannel side in the first direction and reach the main bottom surface.

According to the above configuration, the heights of the first groove and the microchannel can be designed to be substantially consistent with each other.

That is, the neurites grown from the nerve cells cultured in the first well can extend essentially linearly in the first direction and reach the microchannel.

The first groove may be shaped such that an outer edge part of the bottom part of the first recess on a side near the microchannel is connected to an outer edge part of the bottom part of the first recess on a side far from the microchannel when viewed in the second direction.

According to the above configuration, the probability of neurites being introduced into the first groove can be further increased because the opening area of the first groove is increased. As a result, the probability of neurites being introduced into the microchannel is further increased.

A plurality of the microchannels may be formed, a plurality of the first grooves may be formed, the plurality of first grooves each being formed to communicate with each of the plurality of microchannels in the first direction, and the plurality of first grooves may have end portion positions on a side remote from the microchannel as viewed from the second direction, the end portion positions being substantially aligned with each other in a third direction orthogonal to the first direction.

According to the above configuration, the distance the numerous neurites grow from the nerve cells extend to reach the microchannel can be substantially uniformed. This allows the growth conditions of the respective neurites to be uniformed, which contributes to the stabilization of the evaluation at the time of neurite observation and evaluation.

It should be noted that the fact that the end portion positions of the plurality of first grooves are substantially aligned in the third direction means that the displacement of the end portion positions in the first direction is less than 50 µm.

The first groove may be formed not only in a part of the bottom part of the first recess but also in a part of a bottom part of the second recess, and may communicate with an end portion of the microchannel in the first direction on the bottom part side of the second recess.

According to the above configuration, the usability is improved because the degree of freedom in selecting a well in which the nerve cells are to be seeded increases.

Note that in this case, the same structure as the first can be used for the second well. The details are as follows.

The first groove formed on the side of the second recess may extend in the first direction.

The second groove having a downward slope may also be formed on the second recess side. In other words, the second groove formed on the second recess side may connect a main bottom surface, which is a region of the bottom part of the second recess where the first groove is not formed, to an end portion of the first groove in the first direction, wherein the second groove connects the main bottom surface and the end portion of the first groove to form a downward slope from the main bottom surface toward the first groove at a position of an outer peripheral part in the second recess.

The bottom part of the second recess may include a main bottom surface which is a region where the first groove is not formed and an outer peripheral part having a height greater than a height of the main bottom surface, and the first groove may extend from the microchannel side in the first direction and reach the main bottom surface of the second recess.

The outer edge part may be arranged to surround an outer periphery of the main floor surface, viewed in the second direction.

The first groove formed on the second recess side may be shaped such that an outer edge part of the bottom part of the second recess on a side near the microchannel communicates with an outer edge part of the bottom part of the second recess on a side far from the microchannel when viewed in the second direction.

A plurality of the microchannels may be formed, a plurality of the first grooves may be formed on the second recess side, the plurality of first grooves each being formed to communicate with each of the plurality of microchannels in the first direction, and the plurality of first grooves may have end portion positions on a side remote from the microchannel as viewed from the second direction, the end portion positions being substantially aligned with each other in a third direction orthogonal to the first direction.

EFFECT OF THE INVENTION

According to the nerve cell culture chip of the present invention, neurites easily grow from the cultured nerve cells into the microchannel.

BRIEF DESCRIPTION OF THE DRAWINGS

• 1 is a perspective view schematically showing an appearance of a nerve cell culture chip according to a first embodiment.
• 2 is a schematic plan view of the 1 shown nerve cell culture chip 1 seen in the -Z direction.
• 3 is a schematic cross-sectional view of the 2 shown nerve cell culture chips 1 along a line A1-A1 and seen from the -Y side.
• 4 is a schematic perspective cross-sectional view of the 2 shown nerve cell culture chips 1 along the line A1-A1.
• 5 is a partially enlarged view of 4 .
• 6 is a partially enlarged view of 5 .
• 7 is a plan view schematically showing an arrangement mode of the bottom parts of a first recess 10 and a second recess 20 and the 5 shown microchannels 7.
• 8 is a partially enlarged view of 7 .
• 9 is a view schematically showing a state in which neurites grow from nerve cells cultured at the bottom part of the first well 10.
• 10 is a schematic cross-sectional view of a floor plate 3 along a line A2-A2 in 7 .
• 11 is a schematic cross-sectional view of a nerve cell culture chip 1 of a second embodiment along the line A1-A1 in 2 and seen from the -Y side.
• 12 is a plan view schematically showing an arrangement mode of the bottom parts of a first recess 10 and a second recess 20 and the microchannels 7 of the nerve cell culture chip 1 of the second embodiment in the same manner as in 7 shows.
• 13 is a schematic cross-sectional view of a nerve cell culture chip 1 of a third embodiment taken along the line A1-A1 in 2 and taken from the -Y side.
• 14 is a plan view schematically showing an arrangement mode of the bottom parts of a first recess 10 and a second recess 20 and the microchannels 7 of the nerve cell culture chip 1 of the third embodiment in the same manner as in 7 shows.
• 15 is another schematic cross-sectional view of the nerve cell culture chip 1 of the third embodiment along the line A1-A1 in 2 and seen from the -Y side.
• 16 is a schematic plan view showing a nerve cell culture chip 1 of another embodiment in a similar manner to that shown in 12 shows.

METHOD FOR CARRYING OUT THE INVENTION

Each embodiment of a nerve cell culture chip according to the present invention will be described with reference to the drawings.

Please note that the drawings disclosed herein are merely schematic representations. This means that the dimensional relationships in the drawings do not necessarily correspond to the actual dimensional relationships, and the dimensional relationships between the drawings do not necessarily correspond to each other. Furthermore, the number of elements depicted in each drawing does not necessarily correspond to the actual number.

[First embodiment]

A nerve cell culture chip of a first embodiment will be described with reference to the drawings. 1 is a perspective view schematically showing the appearance of a nerve cell culture chip according to the present embodiment. As shown in 1 As shown, the nerve cell culture chip comprises a bottom plate 3 and a main body part 5 arranged in firm contact with the upper surface of the bottom plate 3. A plurality of recesses 6, 6, ... are formed in the main body part 5 at positions spaced apart from each other in a direction parallel to the main surface (XY plane). Hereinafter, one recess 6 among the plurality of recesses 6, 6, ... is referred to as a "first recess 10," and the recess 6 arranged adjacent to and spaced apart from the first recess 10 in the X direction is referred to as a "second recess 20."

In the following description, reference may be made to one of the 1 added XYZ coordinate system. When specifying directions that distinguish between positive and negative orientations, the directions are described with a positive or negative symbol, such as "+X direction" or "-X direction." When the direction is expressed without distinguishing between the positive and negative orientations, the direction is simply referred to as the "X direction." That is, when the direction is described simply as the "X direction" here, both "+X direction" and "-X direction" are included. The same applies to the Y direction and the Z direction.

Both the base plate 3 and the main body part 5 are typically rectangular substrates made of a transparent thermoplastic. Examples of the thermoplastic from which the base plate 3 and the main body part 5 are made include polymethyl methacrylate (PMMA), polycarbonate (PC), cycloolefin copolymer (COC), cycloolefin polymer (COP), and polystyrene (PS). Among these, COP, designated as a medical-grade plastic, is particularly preferred. COP is a thermoplastic with high transparency, low autofluorescence properties, and low drug adsorption properties.

The dimensions of the base plate 3 and the base body part 5 are optional. For example, the dimension in the X direction is 10 mm to 50 mm, and the dimension in the Y direction is 50 mm to 100 mm. The thickness (dimension in the Z direction) of the base plate 3 is, for example, 0.1 mm to 2 mm. The thickness of the base body part 5 is, for example, 2 mm to 15 mm.

In an example of the present embodiment, the dimensions of the bottom plate 3 are X × Y × Z = 26 mm × 76 mm × 1 mm, and the dimensions of the main body part 5 are X × Y × Z = 26 mm × 76 mm × 5 mm.

2 is a schematic plan view of the 1 shown nerve cell culture chip 1 seen in the -Z direction. 3 is a schematic cross-sectional view of the 2 shown nerve cell culture chips 1 along a line A1-A1 and seen from the -Y side.

4 is a schematic perspective cross-sectional view of the 2 shown nerve cell culture chips 1 along the line A1-A1. 5 is a partially enlarged view of 4 . 6 is a partially enlarged view of 5 .

As in the 3 to 5 As shown, the first recess 10 and the second recess 20 are formed to penetrate the main body part 5 in the Z direction from the main surface (top surface) on the +Z side of the main body part 5. In this configuration, both the first recess 10 and the second recess 20 cause a part of the bottom plate 3 to be exposed when viewed in the -Z direction from the +Z side.

At a position between the first recess 10 and the second recess 20, a microchannel 7 is formed on the -Z side of a region where the main body part 5 is formed. A plurality of the microchannels 7 are formed so as to connect the bottom part of the first recess 10 to the bottom part of the second recess 20. Each of the microchannels 7 has an extremely fine structure. Specifically, the channel depth (length in the Z direction) of each microchannel 7 is preferably 3 µm to 80 µm, more preferably 3 µm to 60 µm, and particularly preferably 3 µm to 20 µm. Furthermore, the channel width (length in the Y direction) of each microchannel 7 is preferably 5 µm to 150 µm, more preferably 10 µm to 100 µm, and particularly preferably 15 µm to 50 µm.

For example, by injecting a culture solution containing nerve cells into the first well 10, nerve cells 41 (see 9 ) is seeded at the bottom part (a main bottom surface 13) of the first well 10. Thereafter, the nerve cells 41 are cultured in the first well 10 for a predetermined period of time (e.g., several days) to cause neurites 42 to extend from the nerve cells 41. Thereafter, by introducing the neurites into the microchannels 7, the neurites 42 are cultured in the microchannels 7, and the neurites 42 are observed. At this time, from the viewpoint of examining the neurites 42 for a drug, a solution containing the drug is introduced from the first well 10 or the second well 20. In the present test example, a drug that promotes growth, a drug that causes disturbance, and the like can be added from the second well 20.

The microchannels 7 included in the nerve cell culture chip 1 of the present embodiment are shaped such that the plurality of neurites 42 extending from the nerve cells 41 are intended to be inserted into the microchannel 7 in units of respective neurites 42. The neurites 42 each have a diameter of 0.5 µm to 20 µm, depending on the type of nerve cell 41. Thus, the microchannels 7 are each designed in the above-described dimensional range corresponding to the dimension of the neurite 42 growing from the nerve cell 41.

It should be noted that at the time of introducing the culture solution from the first well 10 or the drug-containing solution from the first well 10 in the initial stage, the excess solution may be drained from the second well 20 side. In this case, the first well 10 is used for the purpose of injecting the solution into the nerve cell culture chip 1, and the second well 20 is used for the purpose of draining the solution from the nerve cell culture chip 1.

As described above, with regard to the introduction of the solution, the nerve cell culture chip 1 is typically installed and used such that the main body part 5 is arranged vertically above the bottom plate 3. That is, the neurites 42 are observed from the side of the bottom plate 3 using a microscope or the like in a state where the neurites 42 (see 9 ) are positioned in the microchannels 7. From this point of view, in particular, the bottom plate 3 is preferably made of a transparent material as described above. Furthermore, when the main body part 5 is colored, at the time of observing the microchannels 7 with a microscope, the neurites 42 located in the microchannels 7 in the direction farther from the -Z side than the bottom plate 3 in the +Z direction overlap with the main body part 5 located on the +Z side of the microchannels 7, possibly interfering with the observation of the neurites 42. From this point of view, the main body part 5 is also preferably made of a transparent material.

As in the 6 to 8 As shown, the nerve cell culture chip 1 of the present embodiment has grooves (hereinafter referred to as “first grooves 15”) connecting the main bottom surface 13 of the first recess 10 with the microchannels 7 at the end portions of the microchannels 7 on the side of the first recess 10. 7 is a plan view schematically showing a manner of arranging the bottom parts of the first recess 10 and the second recess 20 and the microchannels 7. 8 is a partially enlarged view of 7 .

Note that in the present embodiment, the first recess 10 and the second recess 20 are adjacent to each other in the X direction, and the X direction corresponds to a "first direction." Note that the Z direction corresponds to a "second direction," and the Y direction corresponds to a "third direction."

At a location between the first recess 10 and the second recess 20, the microchannels 7 are formed on the -Z side of the main body part 5. Therefore, even if the neurites 42 grow from the nerve cells 41 cultured in the first recess 10, it is a stochastic event that the grown neurites 42 are correctly inserted into the microchannels 7.

On the other hand, in the nerve cell culture chip 1 of the present embodiment, the first grooves 15 are formed in a part of the bottom part of the first depression 10 is formed. The first grooves 15 are connected to the end portions of the microchannels 7 in the X direction (more precisely, the end portions on the -X side). The point that the neurites 42 are easily introduced into the microchannels 7 by the formation of the first grooves 15 is explained with reference to 9 described. 9 is a view schematically showing a state in which the neurites grow from the nerve cells cultured in the bottom part of the first well 10. Note that, for the convenience of description, the first grooves 15 and the microchannels 7 in 9 are shown enlarged.

As described above, the microchannels 7 are provided for the purpose of introducing the neurites 42 derived from the nerve cells 41 cultured in the first well 10 (see 9 ) have grown. According to the configuration of the present embodiment, the first grooves 15 are formed in a part of the bottom part of the first recess 10 in which the nerve cells 41 are located. Therefore, the growth of neurites along the first grooves 15 can be promoted while the tip ends of the neurites 42 grown from the nerve cells 41 are located at the bottom part of the first recess 10. Since the first grooves 15 communicate with the end portions (end portions on the -X side) of the microchannels 7 in the X direction, the neurites 42 extending along the first groove 15 can thus be easily inserted into the microchannels 7.

From the above point of view, it is preferable that the concavo-convex width and depth of each first groove 15 be designed to have substantially the same dimensions as the flow path width and flow path depth of each microchannel 7. That is, the depth (length in the Z direction) of the first groove 15 is preferably 3 µm to 80 µm, more preferably 3 µm to 60 µm, and particularly preferably 3 µm to 20 µm. Further, the concavo-convex width (length in the Y direction) of the first groove 15 is preferably 5 µm to 150 µm, more preferably 10 µm to 100 µm, and particularly preferably 15 µm to 50 µm.

A lithography method can be used to manufacture the first grooves 15 included in the nerve cell culture chip 1 of the present embodiment. An example of a method for manufacturing the nerve cell culture chip 1 will be described below.

(Production of the plate element)

The base plate 3 and the main body part 5, which form the nerve cell culture chip 1, are manufactured. At this point, for example, both the base plate and the main body part are rectangular, flat, plate-shaped elements.

(Shaping of the base body part 5)

At the locations of the base body part 5 where the plurality of recesses 6 are to be formed, through holes are formed by a process such as cutting or injection molding.

(Forming of the base plate 3)

Using lithography technology, the area where the first grooves 15 are to be formed and the area where the microchannels 7 are to be formed are etched to a shallow depth. The etching depth is determined according to the depth of the first groove 15 and the channel depth of the microchannel 7 as described above. In a case where the first groove 15 and the microchannel 7 have the same dimension, a concave-convex groove is formed, the groove being formed by expanding the first groove 15 substantially toward the area where the microchannel 7 is to be formed. Thereafter, the base body part 5 is bonded to the upper surface of the bottom plate 3 to cover a part of the upper surface of the concave-convex groove with the base body part 5, and as a result, the microchannels 7 are formed.

At the time of this etching, etching is also performed simultaneously in a region other than the region where the first grooves 15 are to be formed, the region being surrounded by the outer edge part of the portion corresponding to the bottom part of the recess 6. As a result, for example, the main bottom surface 13 and an outer edge part 17 having a high height position around the main bottom surface 13 are formed in a portion constituting the bottom part of the first recess 10 (see 7 ).

10 is a schematic cross-sectional view of the base plate 3 along a line A2-A2 in 7 . As in 10 As shown, the outer edge part 17, which has a higher height than the main bottom surface 13, is formed in a different section than the area in which the first grooves 15 are to be formed.

(Connecting step)

The base plate 3 and the base body part 5 which have been subjected to a forming process in this way are joined together, and thus the 1 to 3 described nerve cell culture chip 1. As a bonding method, bonding using surface modification by light or plasma, thermal bonding, bonding bonding using an adhesive, bonding using a solvent, or the like. An example of the bonding method is as follows.

First, the bonding surfaces of the bottom plate 3 and the base body part 5 are each subjected to a surface activation treatment. A method including ultraviolet irradiation can be used for the surface activation treatment. A specific example is irradiation with vacuum ultraviolet (VUV) rays with a wavelength of 200 nm or less from an ultraviolet light source. As the ultraviolet light source, a xenon (Xe) excimer lamp with a peak wavelength near 172 nm, a low-pressure mercury lamp with an emission line at 185 nm, a deuterium lamp with an emission line in a wavelength range of 120 to 200 nm, or the like can be suitably used. The illuminance of the vacuum ultraviolet rays is, for example, 10 to 500 mW/cm ² , and the irradiation time is adjusted according to the material for forming the bottom plate 3 and the main body part 5 and is, for example, 0.1 to 60 seconds.

Next, the joining surfaces of the bottom plate 3 and the base body part 5, which have undergone the surface activation treatment, are brought into contact with each other and pressed using a press machine or the like to join the bottom plate 3 and the base body part 5. This step is performed in a heated environment as required to reinforce the joining. During the joining, the joining conditions, such as the heating temperature and the pressing force, are determined depending on the manufacturing material of the bottom plate 3 and the base body part 5. Regarding the specific conditions, the temperature during the pressing is, for example, 40 to 150°C, and the pressing force for the joining is, for example, 0.1 to 10 MPa. This joining step is preferably performed in a state where the surface activation state of the joining surface of both the bottom plate 3 and the base body part 5 is maintained, and from this point of view, the joining step is preferably performed within, for example, 10 minutes after the completion of the ultraviolet irradiation.

It should be noted that after pressing the bottom plate 3 and the base body part 5, heating may be continued for a certain period of time if necessary. As a detailed example, after the pressing state of the bottom plate 3 and the base body part 5 is maintained for a predetermined period of time, the pressing state may be released and the temperature may be raised to a predetermined temperature, and the temperature may be maintained until a desired joining state is achieved. In this case, the predetermined temperature is a temperature at which the bottom plate 3 and the base body part 5 are not deformed by heating.

Thereafter, the cooling step produces the nerve cell culture chip 1 in which the base body part 5 is firmly in contact with the upper surface of the base plate 3.

Note that in the nerve cell culture chip 1 of the present embodiment described above with reference to 3 to 7 described above, a structure similar to that of the first well 10 is also adopted on the second well 20 side. That is, in the nerve cell culture chip 1 of the present embodiment, grooves (first grooves 25) are formed that connect the end portions of the microchannels 7 on the second well 20 side with a main bottom surface 23 of the second well 20. With this configuration, the neurites 42 are easily inserted into the microchannels 7 even when the nerve cells 41 are seeded on the second well 20 side, and thus the degree of freedom in selecting a well in which nerve cells are to be seeded is increased.

However, in the present invention, in a case where the culture solution containing the nerve cells 41 is injected from the first well 10 side and the nerve cells 41 are seeded in the bottom part of the first well 10, it is optional whether or not the first groove 25 is formed on the second well 20 side in the nerve cell culture chip 1. This similarly applies to each of the following embodiments.

It should be noted that, as in the 7 to 9 As shown, the end portions of the first grooves 15 on the side opposite the microchannels 7 (-X side) are preferably substantially aligned with each other in the Y direction. By forming them in this manner, the distance by which the plurality of neurites 42 grown from the nerve cells 41 extend to reach the interior of the microchannels 7 can be substantially uniformed, which can uniform the growth conditions of the respective neurites 42.

Note that in the present embodiment, the outer edge part 17 is formed on the outer periphery of the main bottom surface 13 forming the bottom part of the first recess 10 (see 7 and 9 ). By providing the outer edge portion 17, the neurite 42 located on the outer edge portion 17 is also easily guided into the first groove 15, increasing the likelihood of the neurites 4 being guided into the microchannels 7. The width of the outer edge portion 17 is preferably equal to or greater than the width of the microchannel 7, and more preferably equal to or greater than twice the width of the microchannel 7. This similarly applies to an outer edge portion 27 provided on the outer periphery of the main bottom surface 23 of the second recess 20.

[Second embodiment]

A second embodiment of a nerve cell culture chip 1 will be described in locations different from those of the first embodiment. Note that components common to those of the first embodiment are denoted by the same reference numerals, and their description will be omitted where appropriate.

A schematic perspective view of the nerve cell culture chip 1 of the present embodiment is the same as that shown in 1 , and a schematic plan view in -Z direction is the same as that in 2 .

11 is a schematic cross-sectional view of the nerve cell culture chip 1 of the present embodiment taken along the line A1-A1 in 2 and is taken from the -Y side, and is in the same way as 3 Furthermore, 12 a plan view schematically showing an arrangement mode of the bottom parts of a first recess 10 and a second recess 20 and microchannels 7 of the nerve cell culture chip 1 of the present embodiment in the same manner as in 7 represents.

The nerve cell culture chip 1 of the present embodiment differs from the first embodiment in that the first grooves 15 are formed over the entire bottom portion of the first recess 10. Note that, similarly, the first grooves 25 are also formed over the entire bottom portion of the second recess 20. However, as described above, the first grooves 25 are optionally formed. According to this configuration, even if the neurite 42 grows in any direction, it can be fitted into the first groove 15 and guided to the microchannel 7 side when growing in a direction approaching the first groove 15.

[Third Embodiment]

A third embodiment of a nerve cell culture chip 1 will be described in locations different from those of the first embodiment. Note that components common to those of the first embodiment are denoted by the same reference numerals, and their descriptions will be omitted where appropriate.

A schematic perspective view of the nerve cell culture chip 1 of the present embodiment is the same as in 1 , and a schematic plan view in -Z direction is the same as in 2 .

13 is a schematic cross-sectional view of the nerve cell culture chip 1 of the present embodiment taken along the line A1-A1 in 2 and is taken from the -Y side, and is in the same way as 3 Furthermore, 14 a plan view schematically showing an arrangement mode of the bottom parts of a first recess 10 and a second recess 20 and microchannels 7 of the nerve cell culture chip 1 of the present embodiment in the same manner as 7 shows.

The nerve cell culture chip 1 of the present embodiment differs from the first embodiment in that an outer edge portion 17 is not formed at the bottom portion of the first recess 10. Note that in the 13 shown structure, the length of the first grooves 15 in the X direction is shorter than in the second embodiment (see 11 ). This structure can also be formed, similarly to the first embodiment, at the time of molding a bottom plate 3 by performing etching using the lithography technique with a shallow depth in the region where the first grooves 15 are to be formed and in the region where the microchannels 7 are to be formed. In the present embodiment, the length of the first groove 15 in the X direction may be equal to that in the second embodiment ( 11 ) be.

According to this configuration, even if the neurite 42 grows in any direction, the neurite 42 grown in a direction approaching the first groove 15 can be fitted into the first groove 15 and guided to the microchannel 7 side.

As in 13 As shown, in the nerve cell culture chip 1 of the present embodiment, there is a step between the main bottom surface 13 and the bottom part of the first groove 15. Under the Aspect of easier insertion of the neurites 42 into the first groove 15 when the neurites 42 are separated from the nerve cells 41 (see 9 ) sown and cultivated on the main soil surface 13 of the first depression 10 extend in the direction of the first groove 15, a second groove 51 having a downward slope connecting the height of the main soil surface 13 of the first depression 10 with the first groove 15 may be formed, as shown in 15 shown. Since the position of the end portion on the -X side of the first groove 15 is located further inward than the outer edge of the first recess 10, an area in which the second groove 51 is formed can be secured. The second groove 51 can be formed by applying a technique such as injection molding, cutting, or stamping the bottom plate 3.

Please note that 15 shows a state in which a second groove 52 having a downward slope and connecting a main bottom surface 23 of the second recess 20 and the height of a first groove 25 is also formed on the second recess 20 side. However, as described above, whether the first groove 25 is formed or not is optional, and of course, whether the second groove 52 is formed or not is also optional.

[Other embodiments]

Further embodiments are described below.

<1> In the 1 and 2 The nerve cell culture chip 1 shown in FIG. 1 illustrates a case in which the wells 6, 6, ... are arranged in a matrix along the sides of the base plate 3 and the main body part 5 with a rectangular main surface, but this mode is merely an example. That is, the wells 6, 6, ... included in the nerve cell culture chip 1 can adopt any arrangement mode.

For example, the main surfaces of the base plate 3 and the main body part 5 can have a circular or square shape. Furthermore, the recesses 6, 6, ... can be arranged in a staggered grid pattern. As another example, only one pair of the recesses 6, 6 (only the first recess 10 and the second recess 20) can be formed in the nerve cell culture chip 1.

<2> In the above embodiment, the microchannels 7 are provided so that the first recess 10 and the second recess 20 are arranged adjacent to each other. As shown in 16 However, as shown, for example, the second recess 20 may be adjacent to both the first recess 10 and a third recess 30, and the microchannels 7 may also be formed between the second recess 20 and the third recess 30. In this case, first grooves 35 may be formed at the bottom part of the third recess 30 to communicate with the end portions of the microchannels 7 on the third recess 30 side formed between the second recess 20 and the third recess 30. Note that in 16 a reference numeral 33 denotes a main bottom surface forming the bottom part of the third recess 30, which is similar to the main bottom surface 13 of the first recess 10.

Note that in 16 a case is taken as an example in which the first grooves (15, 25, 35) have a similar shape to the first grooves (15, 25) included in the nerve cell culture chip 1 of the second embodiment described above with reference to 12 described. However, in this other embodiment, the shape of the first groove (15, 25) described above in the first embodiment or the third embodiment can also be adopted.

<3> The present invention is not limited to the above-described embodiment and includes various modifications. For example, the above-described embodiments have been described in detail for a better understanding of the present invention and are not necessarily limited to those with all the configurations described. The scope of the present invention is indicated in the claims, and it is intended to include meanings corresponding to the claims and all modifications within the scope.

DESCRIPTION OF REFERENCE SYMBOLS

1

Nerve cell culture chip

3

base plate

5

Basic body part

6

Well

7

Microchannel

10

First well

13, 23, 33

Main floor area of the depression

15, 25, 35

First groove

17, 27

outer edge part

20

Second well

30

Third well

41

nerve cell

42

Neurite

51, 52

Second groove

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2021/015213 [0005]
• JP-T-2012-504949 [0005]

Claims (8)

A nerve cell culture chip comprising: a bottom plate, a main body portion firmly in contact with an upper surface of the bottom plate, a first recess and a second recess formed at positions spaced apart in a first direction parallel to a main surface of the main body portion so as to penetrate the main body portion and expose the bottom plate, a microchannel connecting the first recess to the second recess in the first direction in a region overlapping the main body portion in a second direction orthogonal to the main surface of the main body portion, and a first groove formed in a part of a bottom portion of the first recess and communicating with an end portion of the microchannel in the first direction. Nerve cell culture chip according to Claim 1 , wherein the first groove extends in the first direction. Nerve cell culture chip according to Claim 1 , further comprising a second groove connecting a main bottom surface, which is a region of the bottom part of the first recess in which the first groove is not formed, with an end portion of the first groove in the first direction, the second groove connecting the main bottom surface and the end portion of the first groove so as to form a downward slope from the main bottom surface to the first groove at a position of an outer peripheral part in the first recess. Nerve cell culture chip according to Claim 1 wherein the bottom part of the first recess has a main bottom surface which is a region in which the first groove is not formed, and an outer edge part having a height greater than a height of the main bottom surface, and the first groove extends from the microchannel side in the first direction and reaches the main bottom surface. Nerve cell culture chip according to Claim 4 , wherein the outer edge part is arranged to surround an outer periphery of the main bottom surface as viewed in the second direction. Nerve cell culture chip according to Claim 1 , wherein the first groove is formed to connect an outer edge part of the bottom part of the first recess on a side near the microchannel with an outer edge part of the bottom part of the first recess on a side remote from the microchannel when viewed in the second direction. Nerve cell culture chip according to one of the Claims 1 until 6 , wherein a plurality of microchannels are formed, a plurality of first grooves are formed, the plurality of first grooves each being formed to communicate with each of the plurality of microchannels in the first direction, and the plurality of first grooves having end portion positions on a side remote from the microchannel as viewed from the second direction, the end portion positions being substantially aligned with each other in a third direction orthogonal to the first direction. Nerve cell culture chip according to one of the Claims 1 until 6 , wherein the first groove is formed not only in a part of the bottom part of the first recess but also in a part of a bottom part of the second recess and communicates with an end portion of the microchannel in the first direction on the bottom part side of the second recess.