Multi-chamber biochip for measuring the electrical resistance of cell layers cultured in the biochip and arrangement comprising the biochip
Patent Information
- Application Number
- PCT/EP2026/057364
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-17
- Filing Date
- 2026-03-16
- Publication Date
- 2026-09-24
Smart Images
Figure EP2026057364_24092026_PF_FP_ABST
Abstract
Description
[0001] Multi-chamber biochip for measuring the electrical resistance of cell layers in cultured cells and the comprehensive
[0002]
[0003] The invention relates to a multi-chamber biochip for in v / tro culture of cell layers, which allows a (real-time) measurement of the electrical resistance of cell layers cultured in the biochip, an arrangement comprising such a chip and a measuring unit, and a method for manufacturing such a chip.
[0004] Perfusing cell culture chambers are known from the prior art, allowing in vitro cultivation of cell layers on a membrane (WO 2015 / 169287 Al, DE 102022 123877 Al). Furthermore, microtiter plates with immersed electrodes for measuring the electrical resistance of cell barriers are known, for example. US 2019 / 025240 Al discloses a multi-chamber biochip comprising two superimposed channels separated by a porous membrane. Each channel of the chip contains two electrodes, enabling the measurement of the so-called transepithelial / transendothelial electrical resistance (TEER).TEER is a quantitative method for measuring the integrity and barrier function of cell-cell contacts and their dynamics in cell culture models of endothelial and / or epithelial cell barriers and can, for example, provide information on whether treatments using drugs or chemicals have an influence on the barrier integrity and functionality of a cell model.
[0005] The invention presented here is based on the objective of proposing an improved multi-chamber biochip, its use in a measuring arrangement and its manufacture, by means of which the disadvantages known from the prior art are reduced.
[0006] The problem is solved by the subject matter of the independent and dependent claims. Advantageous embodiments are the subject matter of the dependent claims. According to one aspect of the present invention, a multi-chamber biochip is provided for the in vitro cultivation of cell layers and the measurement of the electrical resistance of the cultured cell layers. The biochip has two superimposed channels separated by a porous membrane and through which fluid can flow. The membrane has a first surface facing the first channel and a second surface facing the second channel. A first channel cover is applied to the first channel opposite the first membrane surface, and a second channel cover is applied to the second channel opposite the second membrane surface.The first channel cover has a first electrically conductive layer on its surface facing the first channel, forming a first electrode, and the second channel cover has a second electrically conductive layer on its surface facing the second channel, forming a second electrode, wherein at least one of the channel covers coated in this way is transparent to visible light. In this context, "transparent" means that at least a certain wavelength range of an incident spectrum of visible light passes through a coated channel cover to a degree of 50%, preferably 70%, or particularly preferably 85% or more. Preferably, both channel covers are transparent. This allows for microscopic evaluation of the biochip cavity using transmitted light microscopy.
[0007] The duct cover can be in the form of a film. The film is typically between 50 µm and 2 mm thick. Preferably, the film is made of polycarbonate (PC) or polyethylene terephthalate (PET). Alternatively, the duct cover can be made of mineral glass with a thickness preferably between 0.1 mm and 2 mm.
[0008] The two superimposed channels of a biochip according to the invention are also referred to as a cavity. The cavity is enclosed by a monolithic frame and is open at the top and bottom. In this context, monolithic means that the frame is formed from a single workpiece. The monolithic design of the frame allows for easier handling of the biochip, since it eliminates the need to join two or more basic elements whose openings (channels, internal spaces, culture chambers, etc.) would require adjustment and bonding before joining. Furthermore, the monolithic frame is more stable, retains its original shape (no stress-induced bending of the frame), does not leak at the bonded joints, and is therefore more practical to handle and use. In particular, higher flow rates of the supplied media (perfusion velocities) can be achieved without leakage.This is particularly advantageous in the establishment of organ models, because perfusion rates similar to those in vivo must be maintained for as long as possible. The elimination of adhesive joints also has the advantage of removing the adhesives that are mandatory in the prior art and could interact adversely with the biological structures. Furthermore, the absence of adhesive joints significantly reduces the probability of leakage, leading to a lower failure rate of the biochip according to the invention and thus to greater customer satisfaction and efficiency. In addition, the dimensional accuracy requirements for the frame can be lower than those for the elements of a multi-element frame or biochip.
[0009] The porous membrane can, for example, be inserted into the cavity from above, such that the cavity is separated from the membrane into the two channels. For this purpose, a circumferential rib or projection can advantageously be provided in the cavity, the upper surface of which serves as a support and connection surface for the membrane. Three or more channels arranged one above the other can also be provided. In the case of, for example, three channels arranged one above the other, the lower channel is separated from the middle channel by a first membrane, and the middle channel is separated from the upper channel by a second membrane. A first circumferential rib can be provided in the cavity at a first level to support the first membrane, and a second circumferential rib can be provided in the cavity at a second level to support the second membrane.
[0010] Advantageously, the upper channel and / or the lower channel each have an inlet and an outlet. The inlet and outlet can be connected to an external media supply. For this purpose, the inlet and outlet can each be connected to media ports (e.g., standard Luer format) for supplying and removing media, respectively. These media ports are advantageously located on the top of the frame. The external media supply can comprise a predetermined volume of a medium and a pump. The medium can be, in particular, a liquid nutrient medium which, as a result of the pump's action, flows through the upper and / or the lower channel, preferably in a closed loop.Culture under flow-through cell culture conditions allows for better maintenance of the viability of biological structures, particularly organ models, organoids, and spheroids, due in part to improved nutrient and oxygen conditions, compared to static cell culture conditions. This makes it possible to maintain the functionality of such biological structures for longer periods for testing purposes.
[0011] The frame preferably has a slide-like format (76 mm x 26 mm ± 3 mm) and typically a height between 1.5 mm and 10 mm. Such a frame can have one cavity or two or more cavities. Preferably, the cavities have a rectangular shape when viewed from above, with edge lengths of 5 mm to 60 mm for the longer edge and 1 mm to 20 mm for the shorter edge. However, other basic geometric shapes, for example square, triangular, polygonal, round, semicircular, or combinations thereof, are also conceivable and suitable.
[0012] The material used to manufacture the frame is advantageously an injection-moldable, biocompatible plastic. Examples of such plastics include polyesters like polyurethanes (PU), polyimides, styrene (SEBS), polypropylene (PP), polystyrene (PS), polycarbonate (PC), polyethylene terephthalate (PET), and cyclic polyolefins (COP and COC). Depending on the material chosen, the frame is manufactured in one piece using an injection molding or casting process, with the appropriate injection molding or casting tools provided.
[0013] The frame is preferably made of polybutylene terephthalate (PBT). PBT is a polymer commonly used to manufacture products subjected to high mechanical stress and / or repeatedly exposed to hot media. The production of medical-grade PBT starting polymers can even be carried out in compliance with GMP (German Medical Device Regulation). PBT is very well suited for injection molding due to its favorable cooling and processing characteristics. In the inventors' experiments, PBT exhibited very low binding capacities to a number of components of the media typically used for flow through the channels, thus advantageously reducing the influence of the frame material on the investigations carried out in the biochip.
[0014] Advantageously, the porous membrane has membrane pores with a diameter between 0.1 pm and 10 pm. Pore diameters between 0.4 pm and 8 pm are even more preferred. The membrane is advantageously between 5 and 50 pm thick. Membrane thicknesses between 10 and 20 pm are even more preferred.
[0015] In preferred embodiments, the first electrically conductive layer has a first electrical contact in a region away from the first channel, and the second electrically conductive layer has a second electrical contact in a region away from the second channel, wherein the first and second contacts are each sealed against the first and second channels, respectively, in a liquid-tight manner. For this purpose, the first channel cover can include a first contact tab pointing away from the first channel, and / or the second channel cover can include a second contact tab pointing away from the second channel. Liquid-tight in this context means that a channel covered by a channel cover can reliably withstand the flow of a medium under a predetermined static or dynamic operating pressure of, for example, 20 mbar to 200 mbar.
[0016] The seal can be achieved by a sealing connection between the top of the frame and the first channel cover, or by a sealing connection between the underside of the frame and the second channel cover. The sealing connection is preferably made by a liquid-tight weld or adhesive seam. A combination of different sealing methods, for example, a combination of adhesive and weld seams, is also possible. The sealing connection is provided, in particular, around the entire circumference of the channel, such that the contact flange lies outside the area of the channel cover enclosed by the seal. If such a contact flange is present, it preferably also has the electrically conductive layer. The channel cover and contact flange are preferably manufactured in one piece (monolithically) from a single substrate, for example, a PC film substrate or PET film substrate, and in particular by cutting or punching.The dimensions of the contact tabs are variably adjustable and can, for example, have a semicircular, triangular, polygonal, or rounded base shape. Preferably, the upper and lower contact tabs are designed as narrow foil strips arranged offset from each other, extending perpendicular to a longitudinal dimension of the channel or biochip when the first and / or second channel cover is applied to the first and / or second channel.
[0017] The first and / or second electrically conductive layer are advantageously applied directly to the channel cover. "Directly applied" means that no intermediate layers, such as an adhesion promoter or adhesive layer, are used. This advantageously reduces the number of materials used in the biochip's fabrication, minimizing the risk of undesirable interactions between media or biological structures used during biochip operation and the biochip's surfaces accessible to these media or structures. However, pretreatment of the channel cover substrate prior to the application of the electrically conductive layer, such as a cleaning and / or activation step, or multi-layer application of the electrically conductive layer, is considered to be included in the term "directly applied."
[0018] The electrically conductive layers can consist of materials such as gold, platinum, indium tin oxide (ITO), or carbon. Application is preferably carried out in a single layer using sputtering (cathode sputtering). A layer can also consist of multiple layers, and the individual layers can comprise different materials from the aforementioned materials. Other, more complex application methods, such as electron beam evaporation or laser evaporation, are also conceivable. An electrically conductive layer with a thickness of approximately 10 nm to 50 nm is advantageous. The layer can be applied to a foil substrate in the form of a larger sheet, from which the channel covers are subsequently cut to the appropriate dimensions. For the typical size of a biochip in microscope slide format, approximately 400 channel covers can be obtained from one square meter of foil substrate. The layer can be applied to the entire surface of the substrate.However, a selective application of the electrically conductive layer to the substrate is preferred. This can be achieved, for example, by pre-masking the substrate. This can be done by placing a paper mask onto the substrate before the coating step, from which the desired outline of the electrically conductive layer has been cut. Such a mask can be sized to fit a larger substrate sheet, for example, one square meter, and can reproduce the desired outline repeatedly, for example, 400 times. This allows for a scaling effect, enabling cost-effective mass production of electrically conductive coated duct covers. The structuring of the coating, or...Its outline can be variably adapted to the requirements placed on the electrode produced by the layer, for example with regard to conductivity, current carrying capacity, shape and / or size.
[0019] Advantageously, the first electrode covers a surface of the first channel opposite the first membrane surface and sealed by the first channel cover by more than 50%, preferably more than 75%, and particularly preferably more than 85%, and / or the second electrode also covers a surface of the second channel opposite the second membrane surface and sealed by the second channel cover by more than 50%, preferably more than 75%, and particularly preferably more than 85%. The aforementioned surface areas of the channels can also be referred to simply as "channel openings".By choosing a large electrode area relative to the channel width, the biochip's TEER measurement sensitivity for small, local changes in membrane permeability and / or cell layers growing on the membrane surface is increased. This is because the larger the electrodes are relative to the membrane area, the more accurately a sum of the TEER signals across the entire membrane is captured. Since the channels are stacked vertically, their width correlates with the size of the membrane surface. A further advantage is that the distance between the electrode and the respective membrane surface remains consistently small over a large area (for example, between 0.5 and 1 mm). This combination of a small distance and a large electrode area ensures that the measurement sensitivity for local cell damage is independent of location.
[0020] Advantageously, the first and / or second contact includes a connector. In a preferred embodiment, the contacts are implemented, as described, by contact tabs, which in turn are connected to the connector. Such a connection can be made directly, for example, by soldering or bonding, or by electrically conductive adhesive bonding the connector to the contact tab. However, an indirect connection of the contact tabs to the connector via conductive traces is preferred. The conductive traces can, for example, be printed onto a printed circuit board, and each of the contact tabs can be connected to a conductive trace, i.e., for example, by adhesive bonding, or preferably by riveting or clamping. The body of the printed circuit board can be integrated into an edge region of the top surface of the biochip, particularly along a longitudinal extension of the biochip.For this purpose, a corresponding recess with the dimensions of the printed circuit board (PCB) can be provided in the frame. Alternatively, the PCB can simply be attached to the side of the frame. In this case, the thickness of the PCB advantageously corresponds to the height of the frame, for example, 3 mm. The conductor track(s) intended for contact with the connector are preferably applied to a surface of the PCB facing away from the frame. The conductor track(s) form a contact area at their end intended for contact with the contact lug, which may, for example, be circularly widened. The respective contact lug can rest on the contact area with its end intended for contact with the conductor track, such that direct contact is established between the conductor track and the electrically conductive layer of the contact lug facing the PCB.A permanent connection can advantageously be established by riveting or punch riveting with a preferably electrically conductive rivet. This type of connection has proven to be particularly reliable, easy to manufacture, and cost-effective for the intended application. The contact or plug connection is specifically intended for connecting an analysis unit.
[0021] According to one aspect of the invention, an arrangement is therefore further provided which includes a multi-chamber biochip, as described above, and an analysis unit for acquiring measurement data.
[0022] Advantageously, the analysis unit comprises a measuring module and a control unit. Preferably, the control unit controls the timing of the measurement and applies an alternating current with an amplitude between preferably 1 pA and 100 pA and a fixed, predetermined frequency between 10 Hz and 100 kHz, preferably between 10 Hz and 1000 Hz, and particularly preferably 530 Hz, through the electrodes of the biochip, which are separated from the porous membrane, for the duration of each individual measurement (usually 0.1 to 1 second). The current flows through the superimposed channels, which are separated from each other by the porous membrane and are flooded with an electrically conductive (cell culture) medium. Cell layers growing adherently to the membrane form an insulating cell barrier, which increases the electrical resistance.A biochip whose channels are flooded with medium and separated by an unplanted membrane exhibits a low reference impedance, the value of which depends primarily on the ion concentration of the medium in the channels and the size and number of pores in the membrane, since the current flow is not disrupted by a cell barrier. With a pore size of 0.4 pm and physiological saline as the medium, the reference impedance is typically around 100 ohms. In contrast, an intact cell barrier, i.e., one or more confluently grown cell layers with intact cell-cell tight junctions, exhibits a high resistance. Such a measurement of the electrical resistance of a cell barrier is also known as a transepithelial / transendothelial electrical resistance measurement (TEER measurement).
[0023] The analysis unit can be configured to perform continuous TEER measurements over extended cultivation periods, such as 24 hours, 48 hours, or several days up to weeks. Such continuous TEER measurements allow for a real-time assessment of cell integrity development and status over the measurement period.
[0024] The measurement module records, for example, voltage, current, and phase shift, and transmits the measured values to an evaluation unit. The evaluation unit calculates, in particular, an electrical impedance (AC resistance) from the transmitted values. The evaluation unit can be integrated into the analysis unit or be an external unit. Data transmission from the measurement module to an external evaluation unit can be wired or, preferably, wireless. For this purpose, a data transmission module can be integrated into the analysis unit. The data transmission module can use wireless protocols such as Bluetooth or WLAN.
[0025] The control unit can include an operating unit where, for example, predetermined parameters for a single measurement and / or parameters for multiple measurements, such as measurement times, a frequency of repeat measurements, and / or a measurement period, can be set. Advantageously, the analysis unit operates autonomously throughout the entire measurement process. This means that, particularly during extended multiple measurements, no user intervention is necessary during the entire measurement process, and the cell-inoculated biochip can, for example, remain in an incubator under ideal culture conditions.
[0026] The analysis unit can be configured for multi-channel measurement to enable multiple measurements to be performed in parallel. This allows for simultaneous comparative measurements under identical conditions in different cavities of a biochip or in different biochips. For example, the effect of different drug concentrations on cell / barrier integrity can be comparatively investigated.
[0027] Advantageously, the analysis unit includes a battery power supply or a combined battery-cable power supply. This allows the analysis unit to be located near the biochips being examined, and it is, for example, very easy to place the arrangement according to the invention in an incubator without having to run a disruptive cable out of the incubator.
[0028] According to a further aspect of the invention, a method for manufacturing a multi-chamber biochip is also provided.
[0029] The fabrication of a multi-chamber biochip according to the invention is achieved by first providing a monolithically produced frame having a cavity open at the top and bottom. A previously provided porous membrane is inserted into the cavity and connected to the frame such that the membrane divides the cavity into two open channels. Furthermore, two channel covers are provided. These can be cut from a larger substrate sheet, as described above. The channel covers are provided on one side with an electrically conductive layer to form an electrode. The coating with the electrically conductive layer can be applied to a larger substrate sheet before the channel covers are cut from the sheet.The supplied, single-sided coated channel covers are then liquid-tightly connected to the top and bottom of the frame to seal the open channels, with the electrodes facing the channels. This liquid-tight connection is preferably achieved by laser welding or bonding. In a further step, the two electrodes are connected away from the channels. In the simplest case, this connection is a soldered connection to a cable or connector. Preferably, the connection is made to a conductor track on a printed circuit board integrated into the frame. This connection is particularly preferably made by riveting or punch riveting, as described in more detail above.
[0030] The invention is explained in more detail below with reference to exemplary embodiments and figures. Figure 1 shows a schematic representation of an exemplary embodiment of a multi-chamber biochip according to the invention in a perspective view;
[0031] Fig. 2 shows a schematic representation of another embodiment of the multi-chamber biochip in a top view;
[0032] Fig. 3 shows a schematic representation of the embodiment of the multi-chamber biochip of Fig. 2 in a side sectional view;
[0033] Fig. 4 shows an embodiment of an arrangement according to the invention, comprising a multi-chamber biochip according to the invention, an analysis unit and an evaluation unit wirelessly connected to the analysis unit.
[0034] Fig. 1 shows a portion of a biochip 1 according to the invention in a perspective sectional view. The biochip 1 comprises a monolithically manufactured frame 2 with a top surface 5 and a bottom surface 6. The frame 2 is approximately 3 mm thick, measured from the top surface 5 to the bottom surface 6, and is manufactured as a monolithic injection-molded component from polybutylene terephthalate. For clarity, the frame in Fig. 1 is not to scale and is shown only in part (indicated by break lines on the left and right of the image). The frame 2 has a rectangular opening in plan view, which extends from the top surface 5 of the frame 1 to its bottom surface 6 and is open on both sides 5 and 6 of the frame 1. The opening is also referred to as a cavity. The perspective sectional view shown in Fig. 1 illustrates the situation when viewed from a plane parallel to the longer side of the cavity.The cavity is divided by a porous PET membrane 8, approximately 20 pm thick, into a first (upper) flowable channel 3 and a second (lower) flowable channel 4. In the example shown in Fig. 1, the first channel 3 faces the top 5 of the frame 2, and the second channel 4 faces the bottom 6 of the frame 2. The membrane 8 has a first membrane surface 9 oriented towards the first channel 3 and a second membrane surface 10 oriented towards the second channel 4. The pores of the membrane 8 have a diameter of approximately 0.4 pm.
[0035] The first flowable channel 3 comprises a first inlet 24 serving as a media supply and a first outlet 25 serving as a media discharge, allowing a first medium to flow through the first channel 3. Similarly, the second channel 4 comprises a second inlet 26 serving as a media supply and a second outlet 27 serving as a media discharge, allowing a first medium to flow through the second channel 4 as well. The first and second media can be identical or differ in their composition. Preferably, the inlets 24, 26 and the outlets 25, 27 are each connected to Luer media connectors arranged on the top side of the biochip 1 (not shown in the example in Fig. 1), which facilitates the connection of external components such as a pump.
[0036] On the first channel 3, which is open towards the top 5 of the frame 2, a first channel cover 11 is applied opposite the first membrane surface 9, and on the second channel 4, which is open towards the bottom 6 of the frame 2, a second channel cover 12 is applied opposite the second membrane surface 10. The channel covers 11, 12 are made of a transparent polycarbonate film approximately 200 µm thick. The dimensions of the channel covers 11, 12 correspond to those of the channel cross-sections plus an allowance to allow the channel covers 11, 12 to rest on the top 5 and bottom 6 of the frame 2, respectively. Furthermore, planar extensions 19, 20 are provided on one side of each of the channel covers 11, 12, which are referred to here as contact lugs 19, 20. In the embodiment shown in Fig. 1, the contact lugs 19, 20 are rectangular.The channel covers 11, 12 are cut from the foil in one piece with their respective contact tabs 19, 20, such that the first contact tab 19 of the first channel cover 11 is offset from the second contact tab 20 of the second channel cover 12 when the channel covers 11, 12 are properly positioned on the channels 3, 4. On its surface 13 facing the first channel 3, the first channel cover 11 has a first electrically conductive layer 15, which forms a first electrode, and the second channel cover 12 also has a second electrically conductive layer 16, which forms a second electrode, on its surface 14 facing the second channel 2. In the example shown in Fig. 1, layers 15, 16 consist of a gold coating with a thickness of approximately 20 nm. The gold coating was applied in a single layer by sputtering and partially covers the channel covers 11, 12 and the associated contact tabs 19, 20.The partial coating was achieved by first masking the uncoated sections of the channel covers 11, 12 and associated contact tabs 19, 20 with a paper mask. The channel covers 11, 12 coated in this way exhibit approximately 85% transparency to visible light.
[0037] Fig. 2 shows an embodiment of a biochip 1 according to the invention in a top view. The base body of the biochip 1 is formed by the frame 2. The frame 2 has a cavity that is divided into two superimposed channels by a membrane. In the view of Fig. 2, only the upper channel 3 of the two channels is visible; the membrane and the lower channel are concealed by the first channel 3, which faces the top of the frame 2. A channel cover 11 is applied to the upper channel 3. The channel cover 11 includes a contact tab 19. An electrically conductive layer 15 is applied in certain areas to the surface 13 (see Fig. 3) of the channel cover 11 facing away from the top 5, extending over the contact tab 19.
[0038] The channel cover 11 is dimensioned larger than the channel 3, so that the channel cover 11 completely covers the channel 3 and rests on the frame 2. A support surface circumferential to the channel 3 can be recessed into the frame 2 for this purpose. The channel cover 11 is connected to the frame 2 in a liquid-tight manner. In the embodiment shown in Fig. 2, the liquid-tight connection 7 between the channel cover 11 and the frame 2 is a first weld 7a circumferential to the channel 3, which is produced by laser welding the channel cover 11 to the frame 2. In the area of the contact lug 19, the weld 7a can be replaced by an adhesive seam to protect the sensitive electrode 15. Away from the channel 3, the contact lug 19 has an electrical contact 17. This is sealed liquid-tight against the channel 3 by means of the weld or adhesive seam 7a, as described above.
[0039] The electrode 15 is connected to a first conductor track 22a located on a circuit board 21 via contact 17. The conductor track 22a leads to a connector 23, which is also located on the circuit board 21. The contact tab 19 rests directly on the conductor track 22a, thus establishing direct contact between the electrode 15, which points towards the first conductor track 22a, and the conductor track 22a. In the contact area, the first conductor track 22a is covered by the electrode 15; for clarity, the conductor track 22a in the contact area is shown with a dashed line. Additionally, the contact tab 19 is firmly connected to the circuit board 21 in the contact area by means of a rivet. The circuit board 21 is recessed in a recess of the frame 2, parallel to a longitudinal extension of the frame 2 and laterally adjacent to the channel 3 (see Fig. 3). Alternatively, the circuit board 22 can be attached to the side of the frame 2.A second contact flag 20, offset from the first contact flag 19, is indicated by a dashed line. This belongs to a lower channel cover 12, which closes the lower channel 4 by being liquid-tightly connected to the underside of the frame 2. With the exception of the second contact flag 20, indicated by a dashed line, the lower channel 4 and the lower channel cover 12 are not shown in Fig. 2 because they are obscured in the view of Fig. 2 by the components of the biochip above it. The lower channel cover 12 also has the electrically conductive coating on its surface 14 facing the lower channel 4, which forms the electrode 16. The electrode 16 extends over the lower contact flag 20 and is connected by means of the contact 18 to a further conductor 22b located on the underside of the circuit board 21, which is connected by means of a via 22c (see Fig. 2).3) also leads to the connector 23. The contact 18 is again sealed liquid-tight against the channel 4 by means of a second weld 7b. The second conductor track 22b is shown with a dashed line because it is hidden by the circuit board 21 in the view of Fig. 2.
[0040] Fig. 3 shows a non-scale sectional view of the biochip from Fig. 2 along section line AA in Fig. 2. In this view, the superimposed channels 3 and 4, separated by the membrane 8, can be seen. A rib 28, which is arranged circumferentially in the lower channel 4 and thus forms the lateral channel wall of the channel 4, serves as a support for the membrane 8. The membrane 8 rests on the upper surface of the rib 28. The membrane 8 is connected to the upper surface of the rib 28 in a liquid-tight manner by means of a third weld seam 7c.
[0041] The first conductor track 22a is located on the top side of the circuit board 21, and the second conductor track 22b is located on the underside of the circuit board 21. The electrodes 15, 16, each pointing towards channels 3, 4, rest directly on the respective conductor tracks 22a, 22b. These contacts are stabilized by riveting the contact lugs 19, 20 to the circuit board 21 in the area of the contact points, corresponding to the contact points 17, 18.
[0042] An embodiment of an arrangement according to the invention, comprising a multi-chamber biochip 1 and an analysis unit 29, is shown in Fig. 4. The multi-chamber biochip includes a monolithic frame 2, which has two cavities, each divided into two superimposed channels 3 and 4, with only the upper channels 3 being provided with a reference numeral in Fig. 4. As described in the previous embodiments, the channels are each covered with channel covers, with only the upper channel covers 11 being provided with reference numerals in Fig. 4. The channel covers each have electrodes pointing towards the channels, which are connected to the connectors 23 via conductor tracks away from the channels, the contact being made as described with reference to Figs. 1 to 3. The biochip 1 is wired to the analysis unit 29 via the connectors 23 by means of the cables 30. Each of the two in Fig.The connector 23 shown in Fig. 4 is connected to the electrodes of the channels assigned to each connector 23. The left cavity of the biochip 1 in Fig. 4 is thus assigned to the left connector 23, and the right cavity is assigned to the right connector 23. The analysis unit 29 is battery-powered and therefore does not require an external power supply. The analysis unit communicates wirelessly via the Bluetooth protocol with an external evaluation unit 35, symbolized in Fig. 4 by the character “<• >”. For this purpose, the analysis unit is equipped with a wireless module 34. The analysis unit also includes a measurement module 31, a control unit 32, and an operating unit 33.
[0043]
[0044] 1 multi-chamber biochip
[0045] 2 monolithic frames
[0046] 3 first flowable channel
[0047] 4 second flowable channel
[0048] 5 Top of the frame
[0049] 6 Underside of the frame
[0050] 7 liquid-tight connection
[0051] 7a first weld
[0052] 7b second weld
[0053] 7c third weld
[0054] 8 porous membrane
[0055] 9 first membrane surface
[0056] 10 second membrane surface
[0057] 11 first channel cover
[0058] 12 second channel cover
[0059] 13 First surface of the first channel cover 14 Second surface of the second channel cover 15 First electrically conductive layer, first electrode 16 Second electrically conductive layer, second electrode 17 First electrical contact
[0060] 18 second electrical contact
[0061] 19 first contact flag
[0062] 20 second contact flag
[0063] 21 circuit board
[0064] 22a first conductor track
[0065] 22b second conductor
[0066] 22c via
[0067] 23 connectors
[0068] 24 Inlet first channel 25 Outlet first channel 26 Inlet second channel 27 Outlet second channel 28 Bridge
[0069] 29 analysis units
[0070] 30 connecting cables
[0071] 31 Measuring module
[0072] 31 Control unit
[0073] 33 Control unit
[0074] 34 Data transmission module 35 Evaluation unit
Claims
1. Multi-chamber biochip (1) for measuring the electrical resistance of cell layers cultured in the biochip, comprising: a first flowable channel (3); a second flowable channel (4); a porous membrane (8); where the two channels (3, 4) are arranged one above the other and separated from each other by the membrane (8); the membrane (8) has a first membrane surface (9) oriented towards the first channel (3) and a second membrane surface (10) oriented towards the second channel (4); a first channel cover (11) is applied on the first channel (3), opposite the first membrane surface (9); a second channel cover (12) is applied on the second channel (4), opposite the second membrane surface (10); the first channel cover (11) has on its surface (13) facing the first channel (3) a first electrically conductive layer (15) which forms a first electrode; the second channel cover (12) has on its surface (14) facing the second channel (4) a second electrically conductive layer (16) which forms a second electrode; at least one of the coated channel covers (11, 12) is transparent to visible light; characterized by that the two superimposed channels (3, 4) are formed by a monolithic frame (2).
2. Multi-chamber biochip (1) according to claim 1, characterized in that the monolithic frame (2) consists of polybutylene terephthalate.
3. Multi-chamber biochip (1) according to claim 1 or 2, characterized in that the porous membrane (8) has membrane pores with a diameter between 0.1 pm and 10 pm, preferably between 0.4 pm and 8 pm.
4. Multi-chamber biochip (1) according to one of the preceding claims, characterized in that the first electrically conductive layer (15) has a first electrical contact (17) in a region away from the first channel (3) and the second electrically conductive layer (16) has a second electrical contact (18) in a region away from the second channel (4), wherein the first contact (17) is sealed liquid-tight against the first channel (3) and the second contact (18) is sealed liquid-tight against the second channel (4).
5. Multi-chamber biochip (1) according to one of the preceding claims, characterized in that the first channel cover (11) comprises a first contact flag (19) pointing away from the first channel (3) and / or the second channel cover (12) comprises a second contact flag (20) pointing away from the second channel (4), wherein the first contact flag (19) also has the first electrically conductive layer (15) and / or the second contact flag (20) also has the second electrically conductive layer (16).
6. Multi-chamber biochip (1) according to one of the preceding claims, characterized in that the electrically conductive layers (15, 16) are applied directly to the channel covers (11, 12).
7. Multi-chamber biochip (1) according to any one of the preceding claims, characterized in that the frame (2) has a top (5) and a bottom (6) and the first channel cover (11) is connected to the top (5) of the frame (2) in a liquid-tight manner, in particular by bonding and / or welding, and the second channel cover (12) is connected to the bottom (6) of the frame (2) in a liquid-tight manner, in particular by bonding and / or welding.
8. Multi-chamber biochip (1) according to any one of claims 4 to 7, characterized in that the contacts (17, 18) comprise a connector (23) for connecting an analysis unit.
9. Multi-chamber biochip (1) according to one of the preceding claims, characterized in that the transparency of the electrically conductive layers (15, 16) is 50%, preferably 70%, particularly preferably 85% or more.
10. Multi-chamber biochip (1) according to one of the preceding claims, characterized in that the electrically conductive layers (15, 16) consist of gold, platinum, indium tin oxide or carbon.
11. Multi-chamber biochip (1) according to one of the preceding claims, characterized in that the first electrode (15) spans a covering surface of the first channel (3) opposite the first membrane surface (9) and closed by the first channel cover (11) and / or the second electrode (16) spans a covering surface of the second channel (4) opposite the second membrane surface (9) and closed by the second channel cover (12) to more than 50%, preferably more than 75%, particularly preferably more than 85%.
12. Arrangement comprising a multi-chamber biochip (1) according to one of the preceding claims and an analysis unit (29) for recording measurement data.
13. Arrangement according to claim 12, characterized in that the analysis unit (29) comprises a measuring module (31) and a control unit (32), wherein the measuring module (31) acquires the measurement data, in particular a voltage, a current, a phase shift, and the control unit (32) controls the timing of the measurement.
14. Arrangement according to one of claims 12 or 13, characterized in that the analysis unit (29) comprises an operating unit (33) and a data transmission module (34) for wireless transmission of the acquired measurement data to an evaluation unit (35).
15. Method for manufacturing a multi-chamber biochip (1), comprising the steps of providing a first channel coverage (11); Coating the first channel cover (11) with a first electrically conductive layer to obtain a first electrode (15); Providing a monolithic frame (2) having a cavity open at the top and bottom; Providing a porous membrane (8); Inserting the membrane (8) into the cavity of the frame (2) and connecting the membrane (8) to the frame (2) such that the membrane (8) divides the cavity into two open channels (3, 4); Liquid-tight connection of the first channel cover (11) to the top (5) of the frame and thus closing the first open channel (3), wherein the first electrode (15) points towards the first channel (3); Providing a second channel cover (12); Coating the second channel cover (12) with a second electrically conductive layer to obtain a second electrode (16); Liquid-tight connection of the second channel cover (12) to the underside (6) of the frame (2) and thus closing the second open channel (4), wherein the second electrode (16) points to the second channel (4); Creating a contact (17) of the first electrode (15) away from the first channel (3); Creating a contact (18) of the second electrode (16) away from the second channel (4).