Nerve cell culture chip

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 AREA

[0001] The present invention relates to a microfluidic device (nerve cell culture chip) for cultivating nerve cells. TECHNICAL BACKGROUND

[0002] Drug discovery research includes a toxicity and safety assessment phase and a efficacy confirmation phase. Impairment of the peripheral nerves by a drug is undesirable, as such impairment significantly impacts a patient's quality of life (QOL). Therefore, understanding the effects on nerves, such as the peripheral nerves (neurotoxicity), is crucial in drug research.

[0003] A conventional method for assessing neurotoxicity is an observational test, in which a reflex movement is observed in a procedure using laboratory animals. In addition, there is an electrophysiological measurement method using a multi-electrode array in a culture test with cultured cells.

[0004] However, the method using laboratory animals is less reliable when applied to the human body, as the animals are a different species. 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 instruments are expensive.

[0005] Therefore, in recent years a method has been proposed in which nerve cells are cultured in a culture chip with a microfluidic device, and neurites are formed from the nerve cells in order to observe the neurites and thus evaluate drug stimulation and its response. Microfluidic devices that can be used for such an application are known, for example, those disclosed in patent documents 1 and 2 below. DOCUMENT ON THE STATE OF TECHNOLOGY 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

[0006] To observe the 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 or not the grown neurites are introduced into the microchannel is a stochastic event, as the direction in which the nerve cells form the neurites is random. Therefore, a large number of nerve cells must be cultured to obtain sufficient data for evaluation. Since nerve cells are generally expensive, it is preferable to observe the neurites while minimizing the number of nerve cells to be cultured.

[0007] In view of the problems mentioned above, an objective of the present invention is to provide a nerve cell culture chip that can increase the likelihood that the neurites grown from the cultured nerve cells will be introduced into a microchannel. MEANS TO SOLVENT THE PROBLEMS

[0008] A nerve cell culture chip according to the present invention comprises: a base plate, a base body part that is firmly in contact with an upper surface of the base plate, a first depression and a second depression formed at positions spaced apart in a first direction parallel to a main surface of the base body part in order to penetrate the base body part and expose the base plate, a microchannel connecting the first depression to the second depression in the first direction in a region that overlaps the base body part orthogonally to the main surface of the base body part in a second direction, and a first groove formed in a part of a base part of the first depression and connected to an end section of the microchannel in the first direction.

[0009] According to the configuration described above, when nerve cells are seeded and cultured in the first well, the neurites that have grown from the nerve cells readily grow along the first groove provided in the lower part of the first well. The microchannel is a channel that connects the first well to the second well in the first direction, and the first groove is connected to an end segment of the microchannel in the first direction. As a result, the grown neurites are easily inserted into the microchannel along the first groove.

[0010] The first groove preferably has a size that allows the neurites to elongate within it. The width of the first groove is preferably 5 µm to 150 µm, more preferably 10 µm to 100 µm, and particularly preferably 15 µm to 50 µm.

[0011] 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.

[0012] The first groove can be configured to extend in the first direction.

[0013] 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 well in which the first groove is not formed, to an end section of the first groove in the first direction, wherein the second groove connects the main bottom surface and the end section of the first groove in such a way as to form a downward slope from the main bottom surface in the direction of the first groove at a position of an outer edge part in the first well.

[0014] According to the configuration above, the neurites extending along the first groove can be more easily introduced into the microchannel through the second groove.

[0015] The bottom part of the first depression can comprise a main bottom surface, which is an area where the first groove is not formed, and an outer edge part with a height greater than the height of the main bottom surface, and the first groove can extend from the microchannel side in the first direction and reach the main bottom surface.

[0016] According to the configuration above, the heights of the first groove and the microchannel can be designed to be essentially the same.

[0017] This means that the neurites that have grown from the nerve cells cultured in the first depression can extend essentially linearly in the first direction and reach the microchannel.

[0018] The first groove can be shaped such that an outer edge part of the bottom part of the first depression is connected on one side near the microchannel to an outer edge part of the bottom part of the first depression on one side far from the microchannel when viewed in the second direction.

[0019] According to the configuration above, the probability of neurites being introduced into the first groove can be further increased because the opening area of ​​the first groove is enlarged. Consequently, the probability of neurites being introduced into the microchannel is further increased.

[0020] A plurality of microchannels can be formed, a plurality of first grooves can be formed, each plurality of first grooves being formed such that they are connected to each plurality of microchannels in the first direction, and the plurality of first grooves can have end-section positions on a side away from the microchannel, as seen from the second direction, the end-section positions being oriented to each other in a third direction orthogonal to the first direction.

[0021] According to the configuration described above, the distance along which the multitude of neurites growing from the nerve cells extend to reach the microchannel can be essentially standardized. This allows the growth conditions of the respective neurites to be standardized, which contributes to stabilizing the evaluation at the time of observation and analysis of the neurites.

[0022] It should be noted that the fact that the end section positions of the plurality of first grooves are essentially aligned in the third direction means that the displacement of the end section positions in the first direction is less than 50 µm.

[0023] The first groove can be formed not only in a part of the bottom part of the first depression, but also in a part of a bottom part of the second depression, and can be connected to an end section of the microchannel in the first direction on the bottom part side of the second depression.

[0024] According to the above configuration, usability is improved because the degree of freedom in selecting a well in which the nerve cells are to be seeded increases.

[0025] It should be noted that in this case, the same structure can be used for the second depression as for the first depression. The details are as follows.

[0026] The first groove formed on the side of the second depression can extend in the first direction.

[0027] The second groove, which has a downward slope, can also be formed on the second side of the depression. In other words, the second groove formed on the side of the second depression can connect a main bottom surface, which is a region of the bottom part of the second depression where the first groove is not formed, with an end section of the first groove in the first direction, the second groove connecting the main bottom surface and the end section of the first groove to form a downward slope from the main bottom surface towards the first groove at a position of an outer edge part in the second depression.

[0028] The bottom part of the second depression can comprise a main bottom surface, which is an area where the first groove is not formed, and an outer edge part with a height greater than the height of the main bottom surface, and the first groove can extend from the microchannel side in the first direction and reach the main bottom surface of the second depression.

[0029] The outer edge portion can be arranged in such a way that it surrounds an outer perimeter of the main floor area, viewed in the second direction.

[0030] The first groove formed on the side of the second depression can be shaped such that, when viewed in the second direction, an outer edge portion of the bottom portion of the second depression on one side near the microchannel is in contact with an outer edge portion of the bottom portion of the second depression on one side far from the microchannel.

[0031] A plurality of microchannels can be formed, a plurality of first grooves can be formed on the side of the second depression, the plurality of first grooves being each formed to be connected to each of the plurality of microchannels in the first direction, and the plurality of first grooves can have end-section positions on a side away from the microchannel, as seen from the second direction, the end-section positions being substantially aligned to each other in a third direction that is orthogonal to the first direction. IMPACT OF THE INVENTION

[0032] According to the nerve cell culture chip of the present invention, the neurites easily grow from the cultured nerve cells into the microchannel. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view that schematically shows the appearance of a nerve cell culture chip according to a first embodiment. Fig. 2 is a schematic top view of the in Fig. 1 shown nerve cell culture chip 1 seen in the -Z direction. Fig. Figure 3 is a schematic cross-sectional view of the in Fig. 2 depicted nerve cell culture chips 1 along a line A1-A1 and viewed from the -Y side. Fig. Figure 4 is a schematic perspective cross-sectional view of the in Fig. 2 depicted nerve cell culture chips 1 along line A1-A1. Fig. 5 is a partially enlarged view of Fig. 4. Fig. Image 6 is a partially enlarged view of Fig. 5. Fig. Figure 7 is a top view that schematically shows an arrangement of the bottom parts of a first depression 10 and a second depression 20 and the in Fig. 5 microchannels shown in Figure 7. Fig. Figure 8 is a partially enlarged view of Fig. 7. Fig. Figure 9 is a view that schematically shows a state in which neurites grow from nerve cells cultured on the bottom part of the first depression 10. Fig. Figure 10 is a schematic cross-sectional view of a base plate 3 along a line A2-A2 in Fig. 7. Fig. Figure 11 is a schematic cross-sectional view of a nerve cell culture chip 1 of a second embodiment along the line A1-A1 in Fig. 2 and viewed from the -Y side. Fig. Figure 12 is a top view which schematically shows an arrangement of the bottom parts of a first well 10 and a second well 20 and the microchannels 7 of the nerve cell culture chip 1 of the second embodiment in the same way as in Fig. 7 shows. Fig. Figure 13 is a schematic cross-sectional view of a nerve cell culture chip 1 of a third embodiment, which is located along the line A1-A1 in Fig. 2 and is taken from the -Y side. Fig. Figure 14 is a top view schematically showing an arrangement of the bottom parts of a first well 10 and a second well 20 and the microchannels 7 of the nerve cell culture chip 1 of the third embodiment in the same way as in Fig. 7 shows. Fig. Figure 15 is another schematic cross-sectional view of the nerve cell culture chip 1 of the third embodiment along line A1-A1 in Fig. 2 and viewed from the -Y side. Fig. Figure 16 is a schematic top view showing a nerve cell culture chip 1 of another embodiment in a similar manner to that shown in Figure 16. Fig. 12 shows. METHOD FOR IMPLEMENTING THE INVENTION

[0033] Each embodiment of a nerve cell culture chip according to the present invention is described with reference to the drawings.

[0034] It should be noted that the drawings disclosed here are merely schematic representations. This means that the dimensional relationships in the drawings do not necessarily correspond to the actual dimensional relationships, and that the dimensional relationships between the drawings do not necessarily correspond to each other. Furthermore, the number of elements shown in each drawing does not necessarily correspond to the actual number. [First embodiment]

[0035] A nerve cell culture chip of a first embodiment is described with reference to the drawings. Fig. Figure 1 is a perspective view schematically showing the appearance of a nerve cell culture chip according to the present embodiment. As in Fig. As shown in Figure 1, the nerve cell culture chip comprises a base plate 3 and a base body 5, which is in fixed contact with the upper surface of the base plate 3. The base body 5 has several wells 6, 6, ... arranged at positions spaced apart from one another in a direction parallel to the main surface (XY plane). Hereinafter, one well 6 from the plurality of wells 6, 6, ... is referred to as the "first well 10", and the well 6 that is located adjacent to and spaced apart from the first well 10 in the X direction is referred to as the "second well 20".

[0036] The following description may refer to one of the Fig. Reference is made to the added XYZ coordinate system. When specifying directions, if a distinction is made between positive and negative orientations, the directions are described with a positive or negative symbol, such as "+X direction" or "-X direction". If the direction is expressed without distinguishing between positive and negative orientations, the direction is simply referred to as "X direction". This means that in a case where the direction is simply described here as "X direction", both "+X direction" and "-X direction" are included. The same applies to the Y direction and the Z direction.

[0037] Both the base plate 3 and the main body part 5 are typically rectangular substrates made of a transparent thermoplastic material. Examples of thermoplastic materials used for base plate 3 and main body part 5 include polymethyl methacrylate (PMMA), polycarbonate (PC), cycloolefin copolymer (COC), cycloolefin polymer (COP), and polystyrene (PS). Of 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.

[0038] The dimensions of the base plate 3 and the main 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 main body part 5 is, for example, 2 mm to 15 mm.

[0039] In one example of the present embodiment, the dimensions of the base plate 3 are X × Y × Z = 26 mm × 76 mm × 1 mm, and the dimensions of the base body part 5 are X × Y × Z = 26 mm × 76 mm × 5 mm.

[0040] Fig. 2 is a schematic top view of the in Fig. 1 shown nerve cell culture chip 1 seen in the -Z direction. Fig. Figure 3 is a schematic cross-sectional view of the in Fig. 2 depicted nerve cell culture chips 1 along a line A1-A1 and viewed from the -Y side.

[0041] Fig. Figure 4 is a schematic perspective cross-sectional view of the in Fig. 2 depicted nerve cell culture chips 1 along line A1-A1. Fig. 5 is a partially enlarged view of Fig. 4. Fig. Image 6 is a partially enlarged view of Fig. 5.

[0042] As in the Fig. As shown in Figures 3 to 5, the first recess 10 and the second recess 20 are configured such that they penetrate the base body part 5 in the Z-direction from the main surface (top side) on the +Z-side of the base body part 5. In this configuration, both the first recess 10 and the second recess 20 cause a portion of the base plate 3 to be exposed when viewed in the -Z-direction from the +Z-side.

[0043] 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 in which the base body part 5 is formed. A plurality of the microchannels 7 are configured to connect the bottom part of the first recess 10 with the bottom part of the second recess 20. Each of the microchannels 7 has an extremely fine structure. More precisely, 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 most 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 most preferably 15 µm to 50 µm.

[0044] For example, by injecting a culture solution containing nerve cells into the first well 10, nerve cells 41 (see Fig. 9) on the bottom part (a main bottom surface 13) of the first well 10. The nerve cells 41 are then cultured in the first well 10 for a predetermined period (e.g., several days) to induce neurites 42 to extend away from the nerve cells 41. The neurites 42 are then cultured in the microchannels 7 by being introduced into them, and their growth is monitored. At this point, with the aim of testing 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 growth-promoting drug, a disturbance-promoting drug, and similar substances can be added from the second well 20.

[0045] The microchannels 7 contained 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 designed to be introduced into the microchannel 7 in units of the 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 within the dimensional range described above, corresponding to the dimension of the neurite 42 growing from the nerve cell 41.

[0046] It should be noted that during the initial phase, when introducing the culture solution from the first well 10 or the drug-containing solution from the first well 10, any excess solution can be drained from the side of the second well 20. In this case, the first well 10 is used for injecting the solution into the nerve cell culture chip 1, and the second well 20 is used for draining the solution from the nerve cell culture chip 1.

[0047] As described above, the nerve cell culture chip 1 is typically installed and used for solution introduction such that the base body part 5 is positioned vertically above the base plate 3. That is, the neurites 42 are observed from the side of the base plate 3 using a microscope or the like in a state where the neurites 42 (see Fig. 9) are positioned in the microchannels 7. From this perspective, the base plate 3 is preferably made of a transparent material, as described above. If the base body part 5 is stained, the neurites 42 located in the microchannels 7, when viewed with a microscope, overlap the base body part 5, which is located on the +Z side of the microchannels 7, in the direction farther from the -Z side than the base plate 3 in the +Z direction. This may interfere with the observation of the neurites 42. Therefore, the base body part 5 is also preferably made of a transparent material.

[0048] As in the Fig. As shown in Figures 6 to 8, the nerve cell culture chip 1 of the present embodiment has grooves (hereinafter referred to as "first grooves 15") that connect the main base surface 13 of the first well 10 with the microchannels 7 at the end sections of the microchannels 7 on the side of the first well 10. Fig. Figure 7 is a top view, which schematically shows an arrangement of the bottom parts of the first depression 10 and the second depression 20 as well as the microchannels 7. Fig. Figure 8 is a partially enlarged view of Fig. 7.

[0049] 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". It should be noted that the Z-direction corresponds to a "second direction" and the Y-direction to a "third direction".

[0050] At a point between the first well 10 and the second well 20, the microchannels 7 are formed on the -Z-side of the basic body part 5. Therefore, even if the neurites 42 grow from the nerve cells 41 cultured in the first well 10, it is a stochastic event that the grown neurites 42 are correctly inserted into the microchannels 7.

[0051] 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 portion of the first well 10. The first grooves 15 are connected to the end sections of the microchannels 7 in the X-direction (more precisely, the end sections 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 addressed with reference to Fig. 9 described. Fig. Figure 9 is a schematic view showing a state in which the neurites grow from the nerve cells cultured in the base of the first depression 10. It should be noted that, for the sake of simplicity, the first grooves 15 and the microchannels 7 in Fig. 9 are shown enlarged.

[0052] As described above, the microchannels 7 are intended for the purpose of introducing the neurites 42, which originate from the nerve cells 41 cultured in the first well 10 (see Fig. 9) have grown. According to the configuration of the present embodiment, the first grooves 15 are formed in a portion of the bottom part of the first depression 10, in which the nerve cells 41 are located. Therefore, the growth of the neurites along the first grooves 15 can be promoted, while the tips of the neurites 42 that have grown from the nerve cells 41 are located at the bottom part of the first depression 10. Since the first grooves 15 are connected to the end sections (end sections 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.

[0053] From the above perspective, it is advantageous that the concave-convex width and depth of each first groove 15 are designed to have essentially 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. Furthermore, the concave-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.

[0054] A lithography process can be used to manufacture the first grooves 15 contained in the nerve cell culture chip 1 of the present embodiment. An example of a process for manufacturing the nerve cell culture chip 1 is described below. (Manufacturing the plate element)

[0055] 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. (Molding of the base body part 5)

[0056] At the points on the base body part 5 where the multitude of depressions 6 are to be formed, through holes are formed by a process such as cutting or injection molding. (Shaping of the base plate 3)

[0057] Using lithography, 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. If the first groove 15 and the microchannel 7 have the same dimensions, a concave-convex groove is formed by widening the first groove 15 essentially in the direction of the area where the microchannel 7 is to be formed. The base body part 5 is then connected to the upper surface of the base plate 3 to cover part of the upper surface of the concave-convex groove with the base body part 5, thus forming the microchannels 7.

[0058] At the time of this etching, etching is also carried out simultaneously in a different area than the area in which the first grooves 15 are to be formed, the area being surrounded by the outer edge portion of the section corresponding to the bottom portion of the recess 6. As a result, for example, the main bottom surface 13 and an outer edge portion 17 with a high elevation around the main bottom surface 13 are formed in a section that forms the bottom portion of the first recess 10 (see Fig. 7).

[0059] Fig. Figure 10 is a schematic cross-sectional view of the base plate 3 along a line A2-A2 in Fig. 7. As in Fig. As shown in Figure 10, the outer edge part 17, which has a higher height than the main base surface 13, is formed in a different section than the area in which the first grooves 15 are to be formed. (Step of connecting)

[0060] The base plate 3 and the main body part 5, which have been subjected to shaping in this way, are joined together, and thus the above with reference to the Fig. The described nerve cell culture chip 1 was obtained from 1 to 3. Joining methods can include joining using surface modification by light or plasma, thermal joining, joining using an adhesive, joining using a solvent, or the like. An example of the joining method is as follows.

[0061] First, the connecting surfaces of the base plate 3 and the main body part 5 are each subjected to a surface activation treatment. A process involving ultraviolet irradiation can be used for this surface activation treatment. A specific example is irradiation with vacuum ultraviolet (VUV) radiation with a wavelength of 200 nm or less from an ultraviolet light source. Suitable ultraviolet light sources include 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 the wavelength range of 120 to 200 nm, or similar. The illuminance of the vacuum ultraviolet radiation is, for example, 10 to 500 mW / cm². 2, and the irradiation time is set according to the material for the formation of the base plate 3 and the main body part 5 and is, for example, 0.1 to 60 seconds.

[0062] Next, the contact surfaces of the base plate 3 and the main body part 5, which have undergone surface activation treatment, are brought into contact and pressed together using a press or similar device to join the base plate 3 and the main body part 5. This step is carried out in a heated environment, as required, to strengthen the bond. The joining conditions, such as the heating temperature and the pressing force, are determined based on the manufacturing material of the base plate 3 and the main body part 5. For example, the temperature during pressing is between 40 and 150 °C, and the pressing force for the joint is between 0.1 and 10 MPa.This joining step is preferably carried out in a state in which the surface activation state of the joining surface of both the base plate 3 and the base body part 5 is maintained, and from this point of view the joining step is preferably carried out within, for example, 10 minutes after completion of the ultraviolet irradiation.

[0063] It should be noted that after pressing the base plate 3 and the main body part 5 together, heating can be continued for a specific period of time if necessary. As a detailed example, after the pressing state of the base plate 3 and the main body part 5 has been maintained for a predetermined time, the pressing state can be released and the temperature raised to a predetermined temperature, which can then be maintained until a desired bond state is achieved. In this case, the predetermined temperature is a temperature at which the base plate 3 and the main body part 5 will not deform due to heating.

[0064] The nerve cell culture chip 1 is then obtained through the cooling step, in which the base body part 5 is firmly in contact with the upper surface of the base plate 3.

[0065] Note that in the nerve cell culture chip 1 of the present embodiment, which is referred to above by reference to the Fig. As described in Figures 3 to 7, a similar structure to that of the first well 10 is also adopted on the side of the second well 20. That is, in the nerve cell culture chip 1 of the present embodiment, grooves (first grooves 25) are formed that connect the end sections of the microchannels 7 on the side of the second well 20 to a main base 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 side of the second well 20, and thus the degree of freedom in selecting a well in which nerve cells are to be seeded is increased.

[0066] However, within the scope of the present invention, in a case where the culture solution containing the nerve cells 41 is injected from the side of the first well 10 and the nerve cells 41 are seeded in the bottom part of the first well 10, it is optional whether the first groove 25 is formed on the side of the second well 20 in the nerve cell culture chip 1 or not. This applies similarly to each of the following embodiments.

[0067] It should be noted that, as in the Fig. Figures 7 to 9 show that the terminal sections of the first grooves 15 on the side opposite the microchannels 7 (-X side) are preferably aligned substantially with each other in the Y direction. By forming them in this way, the distance over which the multitude of neurites 42 growing from the nerve cells 41 extend to reach the interior of the microchannels 7 can be substantially standardized, which can standardize the growth conditions of the respective neurites 42.

[0068] Note that in the present embodiment the outer edge part 17 is formed on the outer circumference of the main base surface 13, which forms the base part of the first depression 10 (see Fig. 7 and Fig. 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, which increases the probability that the neurites 4 will be 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 applies similarly to an outer edge portion 27 provided on the outer circumference of the main bottom surface 23 of the second recess 20. [Second embodiment]

[0069] A second embodiment of a nerve cell culture chip 1 is described at points that differ from those of the first embodiment. It should be noted that components common to those of the first embodiment are designated by the same reference numbers, and their description is omitted where appropriate.

[0070] A schematic perspective view of the nerve cell culture chip 1 of the present embodiment is the same as that shown in Fig. 1, and a schematic top view in the -Z direction is the same as the one in Fig. 2.

[0071] Fig. Figure 11 is a schematic cross-sectional view of the nerve cell culture chip 1 of the present embodiment, shown along the line A1-A1 in Fig. 2 and is viewed from the -Y side, and is in the same way as Fig. 3 shown. Furthermore, Fig. 12 a top view which schematically shows an arrangement 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 way as in Fig. 7 represents.

[0072] The nerve cell culture chip 1 of the present embodiment differs from the first embodiment in that the first grooves 15 extend over the entire bottom portion of the first well 10. Note that, similarly, the first grooves 25 also extend over the entire bottom portion of the second well 20. However, as described above, the first grooves 25 are optional. According to this configuration, the neurite 42, even if it grows in any direction, can be fitted into the first groove 15 and guided to the side of the microchannel 7 if it grows in a direction approaching the first groove 15. [Third embodiment]

[0073] A third embodiment of a nerve cell culture chip 1 is described at points that differ from those of the first embodiment. It should be noted that components common to those of the first embodiment are designated with the same reference numbers, and their description is omitted where appropriate.

[0074] A schematic perspective view of the nerve cell culture chip 1 of the present embodiment is the same as in Fig. 1, and a schematic top view in the -Z direction is the same as in Fig. 2.

[0075] Fig. Figure 13 is a schematic cross-sectional view of the nerve cell culture chip 1 of the present embodiment, shown along the line A1-A1 in Fig. 2 and is viewed from the -Y side, and is in the same way as Fig. 3 shown. Furthermore, Fig. 14 a top view which schematically shows 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 way as Fig. 7 shows.

[0076] 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 on the bottom portion of the first depression 10. Note that in the Fig. In the structure shown in Figure 13, the length of the first grooves 15 in the X-direction is shorter than in the second embodiment (see Figure 13). Fig. 11) This structure can also be formed, similarly to the first embodiment, during the molding of a base plate 3 by performing shallow etching using lithography in the area where the first grooves 15 are to be formed and in the area where the microchannels 7 are to be formed. In the present embodiment, the length of the first groove 15 in the X-direction can be the same as that in the second embodiment ( Fig. 11) be.

[0077] According to this configuration, even if the neurite 42 grows in any direction, the neurite 42 that has grown in a direction approaching the first groove 15 can be fitted into the first groove 15 and guided to the side of the microchannel 7.

[0078] As in Fig. As shown in Figure 13, in the nerve cell culture chip 1 of the present embodiment there is a step between the main base surface 13 and the base part of the first groove 15. From the point of view of easier insertion of the neurites 42 into the first groove 15, when the neurites 42 are separated from the nerve cells 41 (see Figure 13), the step is designed to facilitate the insertion of the neurites 42 into the first groove 15. Fig. 9), which were sown and cultivated on the main soil surface 13 of the first depression 10, extending towards the first groove 15, a second groove 51 with 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 in Fig. Figure 15 shows that since the position of the end section on the -X-side of the first groove 15 is further inward than the outer edge of the first recess 10, an area in which the second groove 51 is formed can be ensured. The second groove 51 can be formed by applying a technique such as injection molding, cutting, or embossing of the base plate 3.

[0079] Note that Fig. Figure 15 shows a state in which a second groove 52 with a downward slope and a main bottom surface 23 of the second recess 20 and the height of a first groove 25 are also formed on the side of the second recess 20. As described above, however, it is optional whether the first groove 25 is formed or not, and of course, it is also optional whether the second groove 52 is formed or not. [Other embodiments]

[0080] Further embodiments are described below.

[0081] <1> In the Fig. 1 and Fig. Figure 2 of the depicted nerve cell culture chip 1 shows 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, ... contained in the nerve cell culture chip 1 can assume any desired arrangement mode.

[0082] For example, the main surfaces of the base plate 3 and the main body part 5 can be circular or square. Furthermore, the wells 6, 6, ... can be arranged in a staggered grid pattern. As another example, only one pair of wells 6, 6 (only the first well 10 and the second well 20) can be formed in the nerve cell culture chip 1.

[0083] <2> In the embodiment above, the microchannels 7 are arranged such that the first recess 10 and the second recess 20 are adjacent to each other. As in Fig. As shown in Figure 16, however, the second depression 20 can, for example, be adjacent to both the first depression 10 and a third depression 30, and the microchannels 7 can also be formed between the second depression 20 and the third depression 30. In this case, first grooves 35 can be formed on the bottom part of the third depression 30 to communicate with the end sections of the microchannels 7 on the side of the third depression 30, which are formed between the second depression 20 and the third depression 30. Note that in Fig. 16 a reference number 33 designates a main floor area which forms the floor part of the third depression 30 which is similar to the main floor area 13 of the first depression 10.

[0084] Note that in Fig. 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) contained in the nerve cell culture chip 1 of the second embodiment, which is described above with reference to Fig. 12. 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.

[0085] <3> The present invention is not limited to the embodiment described above and includes various modifications. For example, the embodiments described above have been described in detail for a better understanding of the present invention and are not necessarily limited to those with all configurations described. The scope of the present invention is specified in the claims, and it is intended that meanings corresponding to the claims and all modifications within the scope are included. DESCRIPTION OF REFERENCE MARKS 1 nerve cell culture chip 3 Base plate 5 Basic body part 6 Wells 7 microchannel 10 First well 13, 23, 33 Main floor area of ​​the depression 15, 25, 35 First nut 17, 27 outer edge part 20 Second well 30 Third Well 41 nerve cell 42 Neurite 51, 52 Second groove QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2021 / 015213

[0005] JP-T-2012-504949

[0005]

Claims

[1] Nerve cell culture chip, comprising: a base plate a basic body part that is firmly in contact with an upper surface of the base plate, a first depression and a second depression formed at positions spaced apart in a first direction parallel to a main surface of the base body part, so that they penetrate the base body part and expose the bottom plate, a microchannel connecting the first well with the second well in the first direction in an area that overlaps the base body part in a second direction orthogonally to the main surface of the base body part, and a first groove formed in part of a bottom part of the first depression and connected to an end section of the microchannel in the first direction. [2] Nerve cell culture chip according to claim 1, wherein the first groove extends in the first direction. [3] 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 depression in which the first groove is not formed, to an end section of the first groove in the first direction, wherein the second groove connects the main bottom surface and the end section of the first groove in such a way that it forms a downward slope from the main bottom surface to the first groove at a position of an outer edge part in the first depression. [4] Nerve cell culture chip according to claim 1, wherein the bottom part of the first depression has a main bottom surface, which is an area in which the first groove is not formed, and an outer edge part with a height that is 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 floor surface. [5] Nerve cell culture chip according to claim 4, wherein the outer edge part is arranged such that, viewed in the second direction, it surrounds an outer circumference of the main base surface. [6] Nerve cell culture chip according to claim 1, wherein the first groove is configured to connect an outer edge part of the bottom part of the first well on a side close to the microchannel with an outer edge part of the bottom part of the first well on a side far from the microchannel when viewed in the second direction. [7] Nerve cell culture chip according to any one of claims 1 to 6, wherein a large number of microchannels are formed, a plurality of first grooves is formed, wherein the plurality of first grooves is each formed such that it is connected to each of the plurality of microchannels in the first direction, and the multitude of first groove end section positions have on a side away from the microchannel, viewed from the second direction, the end section positions being essentially aligned with each other in a third direction orthogonal to the first direction. [8] Nerve cell culture chip according to one of claims 1 to 6, wherein the first groove is formed not only in a part of the bottom part of the first well, but also in a part of a bottom part of the second well and is connected to an end section of the microchannel in the first direction on the bottom part side of the second well.

Images