Micro-fluidic chip and application thereof

Abstract

The invention discloses a micro-fluidic chip and application thereof, the micro-fluidic chip comprises a top plate, a substrate and a cavity located between the top plate and the substrate, a cell modification layer is arranged between the cavity and the substrate, and the cell modification layer is configured to be capable of promoting improvement of cell attachment capability; the substrate comprises a hydrophobic layer, a dielectric layer and a plurality of driving electrodes, and the driving electrodes are configured to be capable of driving liquid drops containing cells to move in the cavity. According to the micro-fluidic chip disclosed by the embodiment of the invention, the cell scratches can be automatically formed, and the cell scratches with controllable forms can be conveniently formed.

Description

Technical Field

[0001] The embodiments of the present application relate to, but are not limited to, microfluidic technology, and particularly to a microfluidic chip and its applications. Background Art

[0002] Cell proliferation and migration ability are important factors for studying the key mechanisms of vascular smooth muscle cells in the formation of atherosclerosis and its complications. It is very necessary to explore the migration mechanism mediated by multiple factors and a research method with good repeatability and high credibility.

[0003] Cell scratch assay is a laboratory technique for studying cell migration movement, repair ability, and cell-cell interaction. The basic principle is as follows: an artificial blank area, called a "scratch / wound", is created on a confluent monolayer of cells. The cells at the edge of the scratch will gradually enter the blank area to heal the "scratch / wound". Images are captured at the beginning and regularly during the cell migration process. By measuring the scratch spacing at different time points and calculating the difference, the migration ability of the cells can be judged. Because it is similar to the in vitro wound healing process, it is also called the wound healing assay, and can be used to observe the effects of exogenous factors such as drugs and genes on cell migration, repair, and interaction.

[0004] The current cell scratch technology mainly has the following disadvantages: 1. Manual scribing is used, resulting in a high human error; 2. If mechanical array scribing is used, the size of the scratch will be fixed during the design and production, and subsequent experiments cannot be modified; 3. Continuous microscopic observation and positioning are required, and repeated calibration is needed during the repeated photographing process, which is time-consuming and laborious. Existing technologies for detecting cell behavior use an optical detection system to analyze images. To observe cell morphology in real time, a live cell workstation must be used, which is very expensive, and the optical system is very costly and large in size.

[0005] Dielectrophoretic wetting is a new way to precisely manipulate single droplets. Thin Film Transistor (TFT) can integrate multiple electrodes and functional resistors. After the two are combined, actions such as droplet dispensing, merging, and splitting can be controlled, and on-chip temperature control can also be achieved to complete biological detection operations such as PCR. Each electrode can change its contact angle through a switch, which has unique advantages in automation and customer customization, and can integrate sensors to complete automatic monitoring. Summary of the Invention

[0006] The following is an overview of the subject matter described in detail in this article. This overview is not intended to limit the protection scope of the present application.

[0007] Embodiments of the present application provide a microfluidic chip and its application. The microfluidic chip can automatically form a cell scratch, facilitating the formation of a cell scratch with controllable morphology.

[0008] Embodiments of the present application provide a microfluidic chip. The microfluidic chip includes: a top plate, a substrate, and a cavity located between the top plate and the substrate. There is a cell modification layer between the cavity and the substrate, and the cell modification layer is configured to be able to promote the improvement of cell adhesion ability.

[0009] The substrate may include a hydrophobic layer, a dielectric layer, and a plurality of driving electrodes. The driving electrodes are configured to be able to drive a droplet containing cells to move in the cavity.

[0010] In an exemplary embodiment of the present application, the cell modification layer is located between the cavity and the hydrophobic layer;

[0011] The hydrophobic layer may include a plurality of cell adhesion regions distributed at intervals. The orthographic projection of the cell adhesion region on the substrate of the substrate completely overlaps with the orthographic projection of the driving electrode on the substrate;

[0012] The cell modification layer at least exposes part of the cell adhesion region.

[0013] In an exemplary embodiment of the present application, at least part of each cell adhesion region is exposed by the cell modification layer.

[0014] In an exemplary embodiment of the present application, the cell modification layer may include a plurality of cell modification patterns;

[0015] The cell modification pattern may be disposed on the cell adhesion region and / or between two adjacent cell adhesion regions.

[0016] In an exemplary embodiment of the present application, the material of the cell modification layer may include any one or more of a first material and a second material; the first material is a substance that can directly mediate or promote cell adhesion ability, and the second material is a substance that can improve the electrostatic attraction and / or hydrophilic-hydrophobic effect of cells.

[0017] In an exemplary embodiment of the present application, the cell modification layer may contain any one or more of extracellular matrix proteins, cell fibronectin, polylysine, and hydrogel.

[0018] Embodiments of the present application also provide a method for making a cell scratch. The method for making a cell scratch includes:

[0019] Inject a solution containing cells into the cavity of the digital microfluidic chip, and the cells adhere to the hydrophobic layer;

[0020] Detach the cells located in the region where the scratch is expected to be formed from the hydrophobic layer and wash them away to form the cell scratch.

[0021] In an exemplary embodiment of the present application, injecting a cell-containing solution into the cavity of the microfluidic chip, and the cells adhering to the hydrophobic layer may include:

[0022] Inject a cell-containing solution into the cavity of the microfluidic chip, energize the driving electrode, reduce the contact angle of the cells located above the driving electrode, and the cells adhere to the hydrophobic layer;

[0023] The detaching of the cells located in the region where the scratch is expected to be formed from the hydrophobic layer may include:

[0024] Cut off the power supply of the driving electrode located below the region where the scratch is expected to be formed, increase the contact angle of the cells located in the region where the scratch is expected to be formed, so as to detach from the hydrophobic layer.

[0025] In an exemplary embodiment of the present application,

[0026] The detaching of the cells located in the region where the scratch is expected to be formed from the hydrophobic layer may include:

[0027] Heat the cells located in the region where the scratch is expected to be formed, so that the cells located in the region where the scratch is expected to be formed are thermally lysed and detached from the hydrophobic layer.

[0028] In an exemplary embodiment of the present application, the detaching of the cells located in the region where the scratch is expected to be formed from the hydrophobic layer may include:

[0029] Inject cell lysate into the cavity of the microfluidic chip;

[0030] Use the driving electrode of the digital microfluidic chip to drive the cell lysate to move to the region where the scratch is expected to be formed, the lysate contacts the cells located in the region where the scratch is expected to be formed, and the cells located in the region where the scratch is expected to be formed are lysed and detached from the hydrophobic layer.

[0031] Injecting a cell-containing solution into the cavity of the digital microfluidic chip, and the cells adhering to the hydrophobic layer of the digital microfluidic chip includes:

[0032] In an exemplary embodiment of the present application, a cell modification layer is provided between the cavity and the hydrophobic layer of the digital microfluidic chip, and the cell modification layer is configured to be able to promote the improvement of cell adhesion ability;

[0033] Inject a cell-containing solution into the cavity of a digital microfluidic chip, and the cells adhere to the cell modification layer. An embodiment of the present application also provides a cell migration assay method, which includes:

[0034] Inject a cell-containing solution into the cavity of a digital microfluidic chip to form a cell-containing droplet in the cavity;

[0035] Use the driving electrode of the digital microfluidic chip to drive the cell-containing droplet to a desired position, and the cell-containing droplet adheres to the cell adhesion area of the hydrophobic layer of the digital microfluidic chip at the desired position;

[0036] Judge the coverage of the cell adhesion area above the driving electrode according to the output signal of the driving electrode, so as to obtain the cell migration situation.

[0037] In an exemplary embodiment of the present application, the step of using the driving electrode of the digital microfluidic chip to drive the cell-containing droplet to a desired position, and the cell-containing droplet adheres to the cell adhesion area of the hydrophobic layer of the digital microfluidic chip at the desired position includes:

[0038] A cell modification layer is provided between the cavity and the hydrophobic layer of the digital microfluidic chip, and the cell modification layer is configured to be able to promote the improvement of cell adhesion ability;

[0039] Use the driving electrode of the digital microfluidic chip to drive the cell-containing droplet to a desired position, and the cell-containing droplet adheres to the cell modification layer at the desired position.

[0040] An embodiment of the present application also provides a cell co-culture method, which includes:

[0041] Inject a solution containing a first cell and a solution containing a second cell into the cavity of a digital microfluidic chip through different injection ports respectively, to form a first droplet containing the first cell and a second droplet containing the second cell in the cavity;

[0042] Use the driving electrode of the digital microfluidic chip to drive the first droplet and the second droplet to desired positions respectively, and the first droplet and the second droplet adhere to the hydrophobic layer of the digital microfluidic chip at the desired positions and grow;

[0043] Judge the coverage of the cell adhesion area above the driving electrode according to the output signal of the driving electrode, so as to judge the relationship between the first cell population formed by the growth of the first cell and the second cell population formed by the growth of the second cell.

[0044] In an exemplary embodiment of the present application, the driving electrodes of the digital microfluidic chip are used to drive the first droplet and the second droplet to move to desired positions respectively, and the first droplet and the second droplet are respectively attached to the hydrophobic layer of the digital microfluidic chip at the desired positions and grow, including:

[0045] A cell modification layer is provided between the cavity of the digital microfluidic chip and the hydrophobic layer, and the cell modification layer is configured to be able to promote the improvement of cell adhesion ability;

[0046] The driving electrodes of the digital microfluidic chip are used to drive the first droplet and the second droplet to move to desired positions respectively, and the first droplet and the second droplet are respectively attached to the cell modification layer at the desired positions and grow.

[0047] The microfluidic chip of the embodiment of the present application is provided with a cell modification layer, and the cell modification layer can improve the adhesion ability of cells entering the cavity of the microfluidic chip on the cavity; moreover, the adhesion ability of cells on the cavity can be weakened or removed according to needs, so as to automatically form a cell scratch, which is convenient for forming a cell scratch with controllable morphology.

[0048] Other features and advantages of the present application will be described in the following specification, and, in part, will become clearer from the specification, or will be understood by implementing the present application. Other advantages of the present application can be realized and obtained through the solutions described in the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The drawings are used to provide an understanding of the technical solutions of the present application, and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solutions of the present application and do not constitute a limitation to the technical solutions of the present application.

[0050] Figure 1 It is a schematic structural diagram of a microfluidic chip according to an exemplary embodiment of the present application;

[0051] Figure 2 It is a top view schematic diagram of a top plate according to an exemplary embodiment of the present application;

[0052] Figure 3 It is a layout schematic diagram of a cell modification pattern according to an exemplary embodiment of the present application;

[0053] Figure 4 It is a layout schematic diagram of another cell modification pattern according to an exemplary embodiment of the present application;

[0054] Figure 5 It is an operation flow schematic diagram of a cell scratch manufacturing method according to an exemplary embodiment of the present application;

[0055] Figure 6Schematic diagram of the operation process of another method for making cell scratches according to an exemplary embodiment of the present application;

[0056] Figure 7 Schematic diagram of the operation process of another method for making cell scratches according to an exemplary embodiment of the present application;

[0057] Figure 8 Schematic diagram of the operation process of a method for measuring cell migration according to an embodiment of the present application;

[0058] Figure 9 Schematic diagram of the operation process of a method for co - culturing cells according to an embodiment of the present application. Detailed implementation manners

[0059] To make the objectives, technical solutions and advantages of the present application clearer and more understandable, the embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that, without conflict, the embodiments and features in the embodiments of the present application can be combined arbitrarily with each other.

[0060] The embodiments of the present application do not necessarily limit the sizes shown in the drawings, and the shapes and sizes of the components in the drawings do not reflect the actual proportions. In addition, the drawings schematically show ideal examples, and the embodiments of the present application are not limited to the shapes or values shown in the drawings.

[0061] The size and proportional relationships between the various film layers or components in the drawings of the present application can be used as a reference in the actual process, which belongs to the embodiments with better technical effects, but is not limited thereto. For example: the thickness and spacing of each film layer can be adjusted according to actual needs.

[0062] The ordinal numbers such as "first" and "second" in the present application are set to avoid confusion of the components and do not represent any order, quantity or importance.

[0063] In the present application, for convenience, words and phrases indicating orientation or positional relationships such as "middle", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are used to describe the positional relationships of the components with reference to the drawings, which are only for facilitating the description of this specification and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the present application. The positional relationships of the components are appropriately changed according to the directions describing the components. Therefore, it is not limited to the words and phrases described in the disclosure, and can be appropriately replaced according to the circumstances.

[0064] In this application, unless otherwise clearly specified and defined, the terms "install", "connect", and "couple" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate member, or a communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0065] In this application, "membrane" and "layer" can be interchanged with each other. For example, sometimes the "hydrophobic layer" can be replaced with the "hydrophobic membrane".

[0066] An embodiment of this application provides a microfluidic chip. Figure 1 It is a schematic structural diagram of a microfluidic chip according to an exemplary embodiment of this application.

[0067] As Figure 1 shown, the microfluidic chip includes: a top plate 10, a substrate 20, and a cavity 30 located between the top plate 10 and the substrate 20. There is a cell modification layer 40 between the cavity 30 and the substrate 20, and the cell modification layer 40 is configured to be able to promote the improvement of cell adhesion ability.

[0068] The microfluidic chip of the embodiment of this application is provided with a cell modification layer, and the cell modification layer can improve the adhesion ability of cells entering the cavity of the microfluidic chip on the cavity; moreover, the adhesion ability of cells on the cavity can be weakened or removed according to needs, so as to automatically form a cell scratch, which is convenient for forming a cell scratch with controllable morphology.

[0069] In an exemplary embodiment of this application, by applying a voltage to the cell modification layer at certain positions, the enhancement effect of the cell modification layer on cell adhesion can be destroyed, and then the cells can be easily detached and removed from the cavity.

[0070] As Figure 1 shown, the top plate 10 can sequentially include a first hydrophobic layer 11, a first dielectric layer 12, and a cover plate 13 along the direction away from the cavity 30. The top plate 10 can include a through hole K that penetrates the first hydrophobic layer 11, the first dielectric layer 12, and the cover plate 13 and communicates with the cavity 30, for injecting and sucking out liquid.

[0071] Figure 2 It is a top view schematic diagram of a top plate according to an exemplary embodiment of this application. As Figure 2As shown, the through-hole K may include an injection port K1 for injecting a sample solution, an inlet / outlet K2 for a cell culture solution, etc. For example, when it is necessary to monitor cells or manipulate droplets (such as when injecting a solution containing cells), the solution can be dropped into the injection ports K1 of the sample solution at the four corners, and the electrodes are used to control the droplets to perform various actions. When it is necessary to change the solution during cell culture, the cell culture solution can be replaced through the inlet / outlets K2 for the cell culture solution on the left and right sides.

[0072] The through-hole K can be formed by laser or mechanical drilling.

[0073] The material of the cover plate 13 can be a conductive material such as ITO, PEDOT:PSS, etc. The material of the first hydrophobic layer 11 can be a material such as CYTOP, Teflon, parylene, etc.

[0074] The cavity 30 can be encapsulated and the height can be controlled by using an adhesive with microspheres of a certain diameter between the top plate 10 and the substrate 20.

[0075] In an exemplary embodiment of the present application, as Figure 1 shown, the substrate 20 may include a second hydrophobic layer 21 and a second dielectric layer 22, and the second hydrophobic layer 21 is located between the cell modification layer 40 and the second dielectric layer 22.

[0076] The cell modification layer can serve as an isolation layer between the hydrophobic layer and the cells, reducing the toxic harm caused by hydrophobic layer materials such as parylene to the cells.

[0077] Dielectrophoretic wetting is a new method that can precisely manipulate a single droplet. In the microfluidic chip of the embodiment of the present application, by providing the second hydrophobic layer 21 and the second dielectric layer 22 on the substrate 20, dielectrophoretic wetting can be performed on the single droplet in the cavity, thereby precisely manipulating the single droplet.

[0078] In an exemplary embodiment of the present application, the second hydrophobic layer 21 can be formed of the same or different material as the first hydrophobic layer 11; the second dielectric layer 22 can be formed of the same or different material as the first dielectric layer 12. For example, the material of the second hydrophobic layer 21 can be a material such as CYTOP, Teflon, parylene, etc.

[0079] In an exemplary embodiment of the present application, as Figure 1 shown, the substrate 20 may further include a substrate 23, a plurality of driving electrodes 24 and a plurality of transistors 25. The substrate 23 is disposed on a side of the second dielectric layer 22 away from the second hydrophobic layer 21. The plurality of driving electrodes 24 are spaced apart in the second dielectric layer 22, and the plurality of transistors 25 are spaced apart in the second dielectric layer 22. Each transistor 25 controls one driving electrode 24.

[0080] In the microfluidic chip according to the embodiment of the present application, a driving electrode 24 and a transistor 25 for controlling the driving electrode are provided in a substrate 20, and a microfluidic chip based on digital microfluidic technology can be formed, which can manipulate droplets with a volume ranging from picoliters to microliters to achieve operations such as cell encapsulation, sample addition, cleaning, and recovery through basic operations such as dispensing, merging, and splitting. During the entire experiment, only a small amount of liquid needs to be added at a specific sample inlet to achieve related operations.

[0081] Moreover, the microfluidic chip based on digital microfluidic technology can not only achieve the manipulation of a single driving electrode to complete the droplet manipulation of the digital microfluidic chip, but also integrate unit components such as storage electrodes and thermosensitive electrodes, so that on-chip temperature control can be achieved to complete biological detection operations such as PCR. In addition, the state of droplets or cells on the driving electrode can be judged by measuring capacitance, and the state of all capacitances on the entire substrate can be obtained by controlling array addressing to obtain the entire cell migration situation.

[0082] In an exemplary embodiment of the present application, the second hydrophobic layer may include a plurality of cell adhesion regions distributed at intervals, and the orthographic projection of the cell adhesion region on the substrate of the substrate completely overlaps with the orthographic projection of the driving electrode on the substrate;

[0083] At least a part of the cell adhesion region is exposed by the cell modification layer.

[0084] Here, "a part of the cell adhesion region" may be a part of the cell adhesion regions in terms of the number of cell adhesion regions, or a part of a cell adhesion region. Therefore, "exposing at least a part of the cell adhesion region" includes that there is no cell modification layer on some of the cell adhesion regions in terms of the number, and a part of at least one cell adhesion region is exposed. As long as the cell adhesion region is not completely covered by the cell modification layer, it is within the protection scope of the present application.

[0085] In an exemplary embodiment of the present application, the transistor 25 may be a thin film transistor (TFT).

[0086] In an exemplary embodiment of the present application, at least a part of each cell adhesion region is exposed by the cell modification layer 40. The cell modification layer may affect the conductivity of the driving electrode. To avoid this possible influence, at least a part of each cell adhesion region can be exposed by the cell modification layer 40, that is, the driving electrode below the cell adhesion region is not completely covered by the cell modification layer 40.

[0087] In an exemplary embodiment of the present application, the cell modification layer 40 may include a plurality of cell modification patterns 41.

[0088] Figure 3 It is a layout schematic diagram of a cell modification pattern according to an exemplary embodiment of the present application;Figure 4 Schematic layout diagram of another cell modification pattern according to an exemplary embodiment of the present application. As Figure 3 shown, a plurality of cell modification patterns 41 can be disposed on the cell adhesion region 211 and between two adjacent cell adhesion regions 211, but do not completely cover each cell adhesion region 211, that is, do not completely cover the driving electrodes below each cell adhesion region 211. As Figure 3 shown, a plurality of cell modification patterns 41 can be disposed between two adjacent cell adhesion regions 211, that is, all the cell adhesion regions 211 are exposed, so as to expose the driving electrodes below the cell adhesion regions 211.

[0089] In an exemplary embodiment of the present application, the material of the cell modification layer may include any one or more of a first material and a second material; the first material is a substance capable of directly mediating or promoting cell adhesion ability, for example, extracellular matrix protein, cell fibronectin (cell fibronectin), etc.; the second material is a substance capable of improving the electrostatic attraction and / or hydrophilic-hydrophobic effect of cells, and by improving the electrostatic attraction and / or hydrophilic-hydrophobic effect of cells, the non-specific adsorption force between the cells and the hydrophobic layer is improved, and then the interaction between the membrane proteins on the cell surface and the culture surface is improved, and finally the cell adhesion ability is improved, for example, polylysine, hydrogel, etc.

[0090] In an exemplary embodiment of the present application, the cell modification layer 40 may contain any one or more of extracellular matrix protein, cell fibronectin, polylysine, and hydrogel.

[0091] In an exemplary embodiment of the present application, the cell modification layer 40 can be formed on the second hydrophobic layer 21 in different ways according to needs. For example: for large-area coating, solution retention, evaporation and other methods can be used to form a large-area cell modification layer 40 at the cell adhesion position; for the cell modification layer 40 with fine dimensions and patterning of the cell modification layer 40, transfer printing or spotting and other methods can be used.

[0092] The embodiment of the present application also provides a method for making a cell scratch, and the method for making a cell scratch includes:

[0093] Injecting a solution containing cells into the cavity of the digital microfluidic chip, and the cells adhere to the second hydrophobic layer below the cavity of the digital microfluidic chip;

[0094] Desorbing the cells located in the region where the scratch is expected to be formed from the second hydrophobic layer and washing them off to form the cell scratch.

[0095] Cell scratching involves how to produce regular scratches. Digital microfluidic chips can be used to control the generation of cell scratches by controlling the driving electrodes, and the length, size, and number of the scratches can all be controlled externally. Under the same external conditions, the effects of different scratches on cells can be compared simultaneously.

[0096] In an exemplary embodiment of the present application, the digital microfluidic chip used in the cell scratching method may be the microfluidic chip described in the embodiment of the present application.

[0097] Figure 5 FIG. 1 is a schematic diagram of the operation flow of a cell scratching method according to an exemplary embodiment of the present application. Figure 5 As shown, in an exemplary embodiment of the present application, the cell scratching method may include:

[0098] A solution containing cells is injected into the cavity of the microfluidic chip described in an embodiment of the present application, and a driving electrode is arranged under the cavity. At this time, the driving electrode is energized, and the contact angle of the cells above the driving electrode is reduced, and the surface is in a "wet" state. As time goes by, the cells settle and can adhere to the surface with better hydrophilicity. At this time, the driving electrode located below the area where the scratch is expected to be formed is powered off, and the contact angle of the cells in the area where the scratch is expected to be formed increases, and the surface becomes hydrophobic, and these cells cannot adhere to the wall. At this time, the non-adherent cells can be washed away by gentle operations such as changing the fluid, forming a cell "scratch".

[0099] Figure 6 FIG. 2 is a schematic diagram of the operation flow of another cell scratching method according to an exemplary embodiment of the present application. Figure 6 As shown, in an exemplary embodiment of the present application, the cell scratching method may include:

[0100] Direct dripping or digital microfluidics technology is used to form microdroplets from the solution containing cells and drive the microdroplets to move to the desired position in the cavity; when the cells adhere to the wall at the desired position, the cells in the desired scratch area are heated so that the cells in the desired scratch area are thermally lysed, and the cell debris is washed away through the fluid replacement process, thereby forming a "scratch".

[0101] In an example embodiment of the present application, a coil-type electrode or a thermal resistor may be provided in the substrate to achieve the purpose of heating the cells.

[0102] Figure 7 FIG. 2 is a schematic diagram of the operation flow of another cell scratching method according to an exemplary embodiment of the present application. Figure 7 As shown, in an exemplary embodiment of the present application, the cell scratching method may include:

[0103] A cell solution containing cells is formed into microdroplets by direct dropping or by using digital microfluidic technology, and the microdroplets are driven to move to a desired position in the cavity; a cell lysate is injected into the cavity of the microfluidic chip; the driving electrode is used to drive the cell lysate to move to a desired scratch-forming area, the lysate contacts the cells located in the desired scratch-forming area, and the cells located in the desired scratch-forming area are lysed, and the cell residues are carried away by the cell lysate, thereby forming a "scratch".

[0104] The embodiment of the present application also provides a cell migration assay method, which includes:

[0105] Inject a cell solution into the cavity of a digital microfluidic chip to form droplets containing cells in the cavity;

[0106] Use the driving electrode of the digital microfluidic chip to drive the droplets containing cells to a desired position, and the droplets containing cells adhere to the cell adhesion area of the second hydrophobic layer at the desired position;

[0107] Judge the coverage of the cell adhesion area above the driving electrode according to the output signal of the driving electrode, so as to obtain the cell migration situation.

[0108] In an exemplary embodiment of the present application, the digital microfluidic chip used in the cell migration assay method may be the microfluidic chip of the embodiment of the present application. Figure 8 It is a schematic diagram of the operation process of a cell migration assay method according to an embodiment of the present application. As Figure 8 shown, in an exemplary embodiment of the present application, the cell migration assay method includes:

[0109] Inject a cell solution into the cavity of the microfluidic chip of the embodiment of the present application, use digital microfluidic technology to form microdroplets from the cell solution and drive the microdroplets to move to a desired position in the cavity and arrange them according to experimental needs; after the cells adhere to the wall, the output signal of the driving electrode covered by the cells (for example, signals such as current and voltage changes of the driving electrode) reflects the cell coverage on the driving electrode, and then the cell migration situation can be obtained. Also, because the driving electrode itself can output its own coordinates, by reducing the electrode size and increasing the measurement frequency, more accurate cell migration information can be obtained.

[0110] The embodiment of the present application also provides a cell co-culture method, which includes:

[0111] A solution containing a first cell and a solution containing a second cell are respectively injected into the cavity of a digital microfluidic chip through different injection ports, and a first droplet containing the first cell and a second droplet containing the second cell are formed in the cavity;

[0112] The driving electrodes of the digital microfluidic chip are used to drive the first droplet and the second droplet to move to desired positions respectively. The first droplet and the second droplet are respectively attached to the second hydrophobic layer at the desired positions and grow;

[0113] Based on the output signal of the driving electrode, the coverage of the cell adhesion area above the driving electrode is judged, so as to judge the relationship between the first cell population formed by the growth of the first cell and the second cell population formed by the growth of the second cell.

[0114] In an exemplary embodiment of the present application, the digital microfluidic chip used in the cell co-culture method can be the microfluidic chip of the embodiment of the present application.

[0115] Figure 9 It is a schematic diagram of the operation process of a cell co-culture method according to an embodiment of the present application. As Figure 9 shown, in an exemplary embodiment of the present application, the cell co-culture method includes:

[0116] Inject a solution containing a first cell A and a solution containing a second cell B into the cavity of the microfluidic chip of the embodiment of the present application; use digital microfluidic technology to form a first droplet containing the first cell A and a second droplet containing the second cell B from the solution containing the first cell A and the solution containing the second cell B, and drive the first droplet and the second droplet to move to desired positions in the cavity and arrange them according to experimental needs;

[0117] After the cells adhere to the wall, the state between the cells can be observed. For example, by arranging the first droplets around the second droplet, the growth of the second cell under the surrounding of the first cell can be observed. Or by arranging the first droplets in a row or a column, and the second droplets in a row or a column, the relationship between the cell population of the second cell and the cell population of the first cell can be observed. For example, the chemotactic relationship, etc. Here, the "chemotactic relationship" refers to the movement tendency based on certain chemical substances in the environment. In this embodiment, it refers to examining whether the first cell A tends to grow towards or away from the direction of the second cell B, or whether the second cell B tends to grow towards or away from the direction of the first cell A.

[0118] Although the embodiments disclosed in this application are as above, the content described is only the embodiments adopted for the convenience of understanding this application and is not intended to limit this application. Any person skilled in the art within the scope of this application can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in this application. However, the scope of protection of this application shall still be subject to the scope defined by the appended claims.

Claims

1. A microfluidic chip, characterized in that, Comprising: A top plate, a substrate, and a cavity located between the top plate and the substrate. There is a cell modification layer between the cavity and the substrate, and the cell modification layer is configured to be able to promote the improvement of cell adhesion ability; the substrate includes a hydrophobic layer, a dielectric layer, and a plurality of driving electrodes, and the driving electrodes are configured to be able to drive droplets containing cells to move in the cavity.

2. The microfluidic chip according to claim 1, wherein, The cell modification layer is located between the cavity and the hydrophobic layer; The hydrophobic layer includes a plurality of cell adhesion regions distributed at intervals, and the orthographic projection of the cell adhesion regions on the substrate of the substrate completely overlaps with the orthographic projection of the driving electrodes on the substrate; The cell modification layer at least exposes part of the cell adhesion regions.

3. The microfluidic chip according to claim 2, characterized in that, At least part of each cell adhesion region is exposed by the cell modification layer.

4. The microfluidic chip according to claim 2, wherein, The cell modification layer includes a plurality of cell modification patterns; The cell modification patterns are arranged on the cell adhesion regions and / or between two adjacent cell adhesion regions.

5. The microfluidic chip according to any one of claims 1 to 4, characterized in that, The material of the cell modification layer includes any one or more of a first material and a second material; the first material is a substance that can directly mediate or promote cell adhesion ability, and the second material is a substance that can improve the electrostatic attraction and / or hydrophilic-hydrophobic effect of cells.

6. The microfluidic chip according to claim 5, characterized in that, The cell modification layer contains any one or more of extracellular matrix proteins, cell fibronectin, polylysine, and hydrogel.

7. A method for making cell scratches, characterized in that, Comprising: Injecting a solution containing cells into the cavity of a digital microfluidic chip, and the cells adhere to the hydrophobic layer of the digital microfluidic chip; Detaching the cells located in the region where a scratch is expected to be formed from the hydrophobic layer and washing them away to form the cell scratch.

8. The method for fabricating a cell scratch according to claim 7, wherein The injecting a solution containing cells into the cavity of a digital microfluidic chip, and the cells adhere to the hydrophobic layer of the digital microfluidic chip includes: Injecting a solution containing cells into the cavity of a digital microfluidic chip, energizing the driving electrodes of the digital microfluidic chip to reduce the contact angle of the cells located above the driving electrodes, and the cells adhere to the hydrophobic layer; The detaching the cells located in the region where a scratch is expected to be formed from the hydrophobic layer includes: Cutting off the power supply of the driving electrodes located below the region where a scratch is expected to be formed to increase the contact angle of the cells located in the region where a scratch is expected to be formed, so as to detach them from the hydrophobic layer.

9. The method for fabricating a cell scratch according to claim 7, wherein The detaching the cells located in the region where a scratch is expected to be formed from the hydrophobic layer includes: Heating the cells located in the region where a scratch is expected to be formed, so that the cells located in the region where a scratch is expected to be formed are thermally lysed and detached from the hydrophobic layer.

10. The method for making cell scratches according to claim 7, characterized in that, The detaching the cells located in the region where a scratch is expected to be formed from the hydrophobic layer includes: Injecting cell lysate into the cavity of the microfluidic chip; The driving electrode of the digital microfluidic chip is used to drive the cell lysate to move to the area where a scratch is expected to be formed. The lysate contacts the cells located in the area where a scratch is expected to be formed, and the cells located in the area where a scratch is expected to be formed are lysed and detached from the hydrophobic layer.

11. The method for making cell scratches according to any one of claims 7 to 10, characterized in that, The injecting the solution containing cells into the cavity of the digital microfluidic chip, and the cells adhering to the hydrophobic layer of the digital microfluidic chip includes: A cell modification layer is arranged between the cavity and the hydrophobic layer of the digital microfluidic chip, and the cell modification layer is configured to be able to promote the improvement of cell adhesion ability; Inject the solution containing cells into the cavity of the digital microfluidic chip, and the cells adhere to the cell modification layer.

12. A method for cell migration assay, characterized in that, It includes: Inject the solution containing cells into the cavity of the digital microfluidic chip to form a droplet containing cells in the cavity; Use the driving electrode of the digital microfluidic chip to drive the droplet containing cells to a desired position, and the droplet containing cells adheres to the cell adhesion area of the hydrophobic layer of the digital microfluidic chip at the desired position; Judge the coverage of the cell adhesion area above the driving electrode by the droplet according to the output signal of the driving electrode, so as to obtain the cell migration situation.

13. The cell migration assay method according to claim 12, wherein The using the driving electrode of the digital microfluidic chip to drive the droplet containing cells to a desired position, and the droplet containing cells adheres to the cell adhesion area of the hydrophobic layer of the digital microfluidic chip at the desired position includes: A cell modification layer is arranged between the cavity and the hydrophobic layer of the digital microfluidic chip, and the cell modification layer is configured to be able to promote the improvement of cell adhesion ability; Use the driving electrode of the digital microfluidic chip to drive the droplet containing cells to a desired position, and the droplet containing cells adheres to the cell modification layer at the desired position.

14. A cell co-culture method, characterized in that, It includes: Inject the solution containing the first cells and the solution containing the second cells into the cavity of the digital microfluidic chip through different injection ports respectively, to form a first droplet containing the first cells and a second droplet containing the second cells in the cavity; Use the driving electrode of the digital microfluidic chip to drive the first droplet and the second droplet to move to desired positions respectively, and the first droplet and the second droplet adhere to the hydrophobic layer of the digital microfluidic chip at the desired positions and grow; Judge the coverage of the cell adhesion area above the driving electrode according to the output signal of the driving electrode, so as to judge the relationship between the first cell population formed by the growth of the first cells and the second cell population formed by the growth of the second cells.

15. The cell co-culture method according to claim 14, wherein The using the driving electrode of the digital microfluidic chip to drive the first droplet and the second droplet to move to desired positions respectively, and the first droplet and the second droplet adhere to the hydrophobic layer of the digital microfluidic chip at the desired positions and grow includes: A cell modification layer is arranged between the cavity and the hydrophobic layer of the digital microfluidic chip, and the cell modification layer is configured to be able to promote the improvement of cell adhesion ability; The driving electrodes of the digital microfluidic chip are used to drive the first droplet and the second droplet to move to desired positions respectively, and the first droplet and the second droplet are respectively attached to the cell modification layer at the desired positions and grow.

Images