A sealed microfluidic device containing a micro-nano sensing chip

Abstract

The utility model relates to biomedical detection technical field discloses a sealed micro -fluidic device containing micro -nano sensing chip, aims at solving the problem of traditional method unable dynamic monitoring macrophage polarization membrane potential, and the high use cost and the insufficient sealing of existing device. The device includes clamp bottom plate, detachable micro -nano sensing chip and clamp cover, and the micro -nano sensing chip is composed of detachable electrode plate module and cell culture module, and the two form cell culture room in combination; the liquid inlet hole, liquid outlet hole and capillary constitute closed loop liquid path, and the sealing washer is equipped at the channel; the detachable telescopic detection electrode stick in the probe hole is connected with signal processing equipment. The device realizes macrophage culture, polarization induction and membrane potential real -time accurate monitoring integration, and the sealing performance is excellent, and the detachable component reduces the maintenance cost, provides reliable tool for the analysis membrane potential and cell polarization correlation.

Description

Technical Field

[0001] This utility model relates to the field of biomedical detection technology, and in particular to a sealed microfluidic device containing a micro-nano sensing chip. Background Technology

[0002] As innate immune cells, macrophages can polarize from the resting M0 type to the M1 type (pro-inflammatory and anti-infection) or the M2 type (pro-repair) under the influence of external signals such as bacterial infection and mechanical stimulation. Changes in membrane potential are a key physiological characteristic of macrophage activation and polarization. Real-time and accurate monitoring of membrane potential changes is of great significance for understanding the cell polarization state and analyzing the polarization regulation mechanism.

[0003] Currently, macrophage polarization monitoring mainly relies on traditional methods such as flow cytometry, PCR, and Western blotting. These methods require sampling and detection at specific time points, making it impossible to dynamically record the entire polarization process of the same batch of cells and capture instantaneous changes in membrane potential. Although existing microfluidic chips can be used for cell electrophysiological monitoring, they are mostly designed for neurons or cardiomyocytes, and core detection components such as electrode modules are mostly fixed structures. If damaged, the entire chip needs to be replaced, resulting in high operating costs. Thirdly, their sealing performance is insufficient, and leakage is prone to occur at the inlet and outlet interfaces, which can contaminate cells or cause distortion of detection signals.

[0004] To address the shortcomings of the existing technology, this invention provides a sealed microfluidic device containing a micro / nano sensing chip. By clearly defining the inlet and outlet liquid paths, adopting a detachable electrode module, and optimizing the sealing structure, it enables stable macrophage culture and real-time accurate monitoring of membrane potential, providing a reliable tool for analyzing the correlation between membrane potential and cell polarization. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a sealed microfluidic device containing micro / nano sensing chips, thereby solving the problem that traditional monitoring methods cannot dynamically record data. To achieve the above objectives, the technical solution adopted by this utility model is as follows: A sealed microfluidic device containing a micro / nano sensing chip includes: a fixture base plate, a micro / nano sensing chip detachably disposed on the upper part of the fixture base plate, and a fixture cover plate detachably disposed on the upper part of the micro / nano sensing chip. The upper part of the fixture base plate is provided with a base plate placement groove for embedding the micro-nano sensor chip, and the fixture base plate is provided with a plurality of first threaded holes along the outer side of the base plate placement groove. The micro / nano sensing chip includes: an electrode plate module detachably disposed in the base plate placement slot, and a cell culture module detachably disposed at the bottom of the electrode plate module; The cell culture module has a cell culture tank at its bottom, and the electrode plate module and the cell culture tank together form a cell culture chamber. A first liquid inlet is provided on one side of the cell culture module, and a first liquid outlet is provided on the other side of the cell culture module. Both the first liquid inlet and the first liquid outlet are connected to the cell culture chamber. The clamp cover plate has several second threaded holes, second liquid inlet holes, second liquid outlet holes, and two probe holes along its thickness direction; Each of the second threaded holes is coaxially arranged with its corresponding first threaded hole, and the fixture cover plate and the fixture base plate are fixed by bolts passing through the second threaded holes and the first threaded holes in sequence. The first liquid inlet and the second liquid inlet are coaxially arranged, the first liquid outlet and the second liquid outlet are coaxially arranged, and capillary tubes are detachably arranged in the first liquid inlet, the second liquid inlet, the first liquid outlet and the second liquid outlet; a retractable detection electrode rod is detachably arranged in the probe hole, and the detection end of the retractable detection electrode rod is operably abutted against the electrode plate module.

[0006] Furthermore, the inlet end of the capillary in the second liquid inlet is connected to the outlet end of the microfluidic drive pump, and the outlet end of the capillary in the second liquid outlet is connected to the inlet end of the microfluidic drive pump, forming a closed-loop liquid circulation.

[0007] Furthermore, the signal transmission end of the retractable detection electrode rod is electrically connected to the signal processing equipment.

[0008] Furthermore, a sealing gasket is provided between the second liquid inlet and the second liquid outlet and the capillary tube, and the inner diameter of the sealing gasket is adapted to the outer diameter of the capillary tube, and the outer diameter of the sealing gasket is adapted to the inner diameter of the second liquid inlet and the second liquid outlet.

[0009] Furthermore, the macrophages in the cell culture chamber are placed on the upper part of the electrode plate module.

[0010] Furthermore, the inner wall of the cell culture chamber is coated with a cell adhesion promoting layer.

[0011] Furthermore, the cell adhesion promoting layer is a collagen coating or a polylysine coating.

[0012] This invention, employing the above technical solution, offers the following technical advantages compared to existing technologies: By clearly designing the corresponding coaxial structure of the first inlet and outlet ports, and the second inlet and outlet ports, and combining this with a detachable capillary tube to form a closed-loop liquid circulation system, it ensures a stable cell culture environment and facilitates component replacement and maintenance. The clamp base plate and cover plate are fixed with coaxial threaded holes and bolts, and combined with matching sealing gaskets at the inlet and outlet ports, the entire device is sealed, effectively preventing liquid leakage and external contamination. The retractable detection electrode rod is detachable and ensures close contact with the electrode plate module, enabling precise membrane potential acquisition when combined with signal processing equipment. Both the electrode plate module and the cell culture module are detachable, allowing for individual replacement after damage, reducing operating costs. The overall device integrates macrophage culture, polarization induction, and membrane potential monitoring, providing reliable support for analyzing the correlation between membrane potential and cell polarization. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the exploded three-dimensional structure of this utility model; Figure 2 This is a three-dimensional structural diagram of the assembled present invention; Figure 3 This is a perspective structural diagram of the cell culture module and electrode plate module during assembly in this utility model. Figure 4 This is a schematic diagram of the structure of this utility model in use; The reference numerals in the attached figures are: 1. Fixture base plate; 11. Base plate placement slot; 12. First threaded hole; 2. Micro / nano sensor chip; 21. Cell culture module; 22. Electrode plate module; 23. First liquid inlet; 24. Cell culture chamber; 25. First liquid outlet; 3. Fixture cover plate; 31. Second threaded hole; 32. Second liquid inlet; 33. Probe hole; 34. Retractable detection electrode rod; 35. Capillary tube; 36. Second liquid outlet; 4. Bolt; 5. Microfluidic drive pump; 6. Signal processing equipment. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0015] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention. Example

[0017] This embodiment provides a sealed microfluidic device containing a micro / nano sensing chip, including: a fixture base plate 1, a micro / nano sensing chip 2, a fixture cover plate 3, bolts 4, a capillary tube 35, a sealing gasket, a retractable detection electrode rod 34, a microfluidic drive pump 5, and a signal processing device 6. The base plate 1 of the fixture base plate 1 has a base plate placement groove 11 that is adapted to the size of the micro-nano sensor chip 2, which can embed the micro-nano sensor chip 2 therein, and prevent the chip from shifting during assembly or liquid circulation. The first threaded hole 12 of the fixture base plate 1 along the outer side of the base plate placement groove 11 corresponds one-to-one with the number and position of the second threaded hole 31 of the fixture cover plate 3, so that the fixture cover plate 3 and the base plate 1 fit tightly together to form a stable sealing structure. The micro / nano sensing chip 2 includes a detachably connected electrode plate module 22 and a cell culture module 21. The electrode plate module 22 is detachably embedded in the base plate placement slot 11, and the cell culture module 21 is detachably set at the bottom of the electrode plate module 22. After the two are assembled, the cell culture tank at the bottom of the cell culture module 21 and the upper part of the electrode plate module 22 together form a cell culture chamber 24, which provides space for macrophage growth and polarization. When the electrode plate module 22 or the cell culture module 21 is damaged or needs to be replaced with different specifications of parts, it can be directly disassembled and replaced separately without replacing the whole, thus reducing the cost of use. The first liquid inlet 23 on one side and the first liquid outlet 25 on the other side of the cell culture module 21 are both connected to the cell culture chamber 24, forming a liquid path layout of "liquid inlet on one side and liquid outlet on one side", which ensures the stability of the cell environment. The clamp cover plate 3 is used to cover and seal the micro-nano sensing chip 2. The second threaded hole 31 opened along the thickness direction is coaxial with the first threaded hole 12 of the clamp base plate 1. After the bolt 4 is inserted and tightened, a uniform pressure can be formed between the clamp cover plate 3 and the base plate 1 to avoid local gaps that may cause liquid leakage. The second liquid inlet hole 32 is coaxially aligned with the first liquid inlet hole 23 of the cell culture module 21, and the second liquid outlet hole 36 is coaxially aligned with the first liquid outlet hole 25 to ensure that the capillary 35 can be smoothly connected after insertion without any obstruction to liquid transport. Two probe holes 33 are symmetrically opened on both sides of the clamp cover plate 3 and correspond to the position of the electrode plate module 22. They are used to accommodate the detachable and retractable detection electrode rod 34. By adjusting the extension stroke of the electrode rod, its detection end is tightly pressed against the electrode plate module 22 to ensure stable transmission of membrane potential signal. The capillary 35 is divided into an inlet capillary and an outlet capillary, both of which are detachable. One end of the inlet capillary passes through the second inlet hole 32 of the clamp cover plate 3 and a sealing gasket, and is inserted into the first inlet hole 23 of the cell culture module 21. One end of the outlet capillary passes through the second outlet hole 36 of the clamp cover plate 3 and a sealing gasket, and is inserted into the first outlet hole 25 of the cell culture module 21. The inner diameter of the sealing gasket is the same as the outer diameter of the capillary 35, and the outer diameter is the same as the inner diameter of the second inlet hole 32 and the second outlet hole 36. After compression, it can completely fill the gap between the capillary 35 and the channel, blocking the liquid leakage path. The other end of the inlet capillary is connected to the outlet end pipeline of the microfluidic drive pump 5, and the other end of the outlet capillary is connected to the inlet end pipeline of the microfluidic drive pump 5, forming a closed-loop liquid circuit. The microfluidic drive pump 5 can precisely control the liquid flow rate to realize the cyclic delivery of culture medium or reagents. In this process, macrophages are placed directly on the upper part of electrode plate module 22, so that the cell membrane is in full contact with electrode plate module 22, and the membrane potential signal can be directly transmitted to the electrode to ensure detection sensitivity. The retractable detection electrode rod 34 has a detachable structure. Its detection end is made of conductive material. After it comes into contact with the electrode plate module 22, it can receive membrane potential signals in real time. Its signal transmission end is electrically connected to the signal processing device 6 through a wire. The signal processing device 6 can set the acquisition parameters, store and display the membrane potential data in real time, which is convenient for experimental personnel to observe and record. When the electrode rod is damaged, it can be directly removed and replaced from the probe hole 33, making maintenance convenient. In a preferred embodiment, the collagen coating (or polylysine coating) applied to the inner wall of the cell culture chamber 24 (including the inner wall of the cell culture tank and the corresponding surface of the electrode plate module 22) enhances the adhesion ability of macrophages through bioadsorption, prevents cells from detaching during the flow of the culture medium, and ensures the continuity of the monitoring process. As a preferred embodiment, the fixture base plate 1, cell culture module 21, and fixture cover plate 3 are made of polydimethylsiloxane (PDMS), which has the characteristics of being resistant to biological corrosion and having high transparency. This avoids deformation or release of harmful substances after long-term contact with the culture medium, and also makes it convenient for experimental personnel to observe the cell state. As a preferred embodiment, the microfluidic driven pump 5 is a circulating microfluidic control pump.

[0018] In use, the device is first assembled: the electrode plate module 22 is detachably embedded into the bottom plate placement groove 11 of the fixture base plate 1, and then the electrode plate module 22 is detachably installed on the upper part of the cell culture module 21 so that the two together form the cell culture chamber 24; sealing gaskets are placed in the second liquid inlet hole 32 and the second liquid outlet hole 36 of the fixture cover plate 3 respectively; the liquid inlet capillary is detachably inserted through the second liquid inlet hole 32 and the sealing gasket and then inserted into the first liquid inlet hole 23; the liquid outlet capillary is detachably inserted through the second liquid outlet hole 36 and the sealing gasket and then inserted into the first liquid outlet hole 25. Cover the upper part of the micro-nano sensing chip 2 with the clamp cover plate 3, align the second threaded hole 31 with the first threaded hole 12, and tighten the bolts 4 in sequence to complete the sealing and fixing of the device; detachably insert the telescopic detection electrode rod 34 into the probe hole 33, and adjust the telescopic stroke until its detection end abuts against the electrode plate module 22; connect the other end of the liquid inlet capillary to the outlet end pipeline of the microfluidic drive pump 5, and connect the other end of the liquid outlet capillary to the inlet end pipeline of the microfluidic drive pump 5 to form a closed loop; connect the signal transmission end of the telescopic detection electrode rod 34 to the signal processing device 6; Cell processing and monitoring were then performed: M0 macrophage suspension was injected into cell culture chamber 24 via microfluidic pump 5 through inlet capillary, with the injection volume matching the volume of cell culture chamber 24; microfluidic pump 5 was stopped, the fluid path was closed, and the device was placed in a cell culture incubator to allow the cells to adhere to the surface of the adhesion-promoting layer; signal processing device 6 was turned on, acquisition parameters were set, microfluidic pump 5 was started to continuously circulate fresh culture medium into cell culture chamber 24, and the resting membrane potential baseline of M0 macrophages was continuously monitored and recorded; Polarization induction and dynamic monitoring were then performed: the microfluidic pump 5 switched the tubing to circulate culture medium containing polarization induction reagent into the cell culture chamber 24, continuously replacing the liquid in the culture chamber; after replacement, fresh culture medium was switched back and continuously circulated, and the signal processing device 6 collected and recorded membrane potential change data in real time; when the membrane potential change was monitored to be stable, the experiment was stopped, the device was disassembled, the electrode plate module 22 and the cell culture module 21 were removed, macrophages in the cell culture chamber 24 were collected, and polarization markers were detected by flow cytometry and polarization-related genes were detected by PCR. The verification results of the traditional method were compared with the real-time membrane potential data to analyze and summarize the intrinsic correlation between membrane potential changes and macrophage polarization state.

[0019] In summary, this invention achieves stable circulating perfusion through a clearly defined closed-loop liquid path design; the detachable electrode plate module, cell culture module, capillary tube, and detection electrode rod reduce maintenance costs; the optimized sealing structure prevents leakage and contamination; and the overall device is adapted to the physiological characteristics and detection needs of macrophages, providing a reliable experimental tool for studying the relationship between membrane potential and cell polarization.

[0020] The above description of this utility model is merely a preferred embodiment of this utility model and does not limit the implementation method and protection scope of this utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of this utility model should be included within the protection scope of this utility model.

Claims

1. A sealed microfluidic device containing a micro / nano sensing chip, characterized in that, include: The fixture base plate (1), the micro / nano sensing chip (2) detachably disposed on the upper part of the fixture base plate (1), and the fixture cover plate (3) detachably disposed on the upper part of the micro / nano sensing chip (2). The upper part of the fixture base plate (1) is provided with a base plate placement groove (11) for embedding the micro-nano sensing chip (2), and the fixture base plate (1) is provided with a plurality of first threaded holes (12) along the outer side of the base plate placement groove (11). The micro / nano sensing chip (2) includes: an electrode plate module (22) detachably disposed in the base plate placement groove (11), and a cell culture module (21) detachably disposed at the bottom of the electrode plate module (22). The cell culture module (21) has a cell culture tank at its bottom, and the electrode plate module (22) and the cell culture tank together form a cell culture chamber (24). A first liquid inlet (23) is provided on one side of the cell culture module (21), and a first liquid outlet (25) is provided on the other side of the cell culture module (21). Both the first liquid inlet (23) and the first liquid outlet (25) are connected to the cell culture chamber (24). The clamp cover plate (3) has several second threaded holes (31), second liquid inlet holes (32), second liquid outlet holes (36), and two probe holes (33) along its thickness direction. Each of the second threaded holes (31) is coaxially arranged with its corresponding first threaded hole (12), and the clamp cover plate (3) and the clamp base plate (1) are fixed by bolts (4) through which the second threaded holes (31) and the first threaded holes (12) are sequentially passed; The first liquid inlet (23) and the second liquid inlet (32) are coaxially arranged, the first liquid outlet (25) and the second liquid outlet (36) are coaxially arranged, and a capillary tube (35) is detachably arranged in the first liquid inlet (23), the second liquid inlet (32), the first liquid outlet (25) and the second liquid outlet (36); a retractable detection electrode rod (34) is detachably arranged in the probe hole (33), and the detection end of the retractable detection electrode rod (34) is operably abutted against the electrode plate module (22).

2. The hermetically sealed microfluidic device containing a micro / nano sensing chip according to claim 1, characterized in that, The inlet end of the capillary (35) in the second liquid inlet (32) is connected to the outlet end of the microfluidic drive pump (5), and the outlet end of the capillary (35) in the second liquid outlet (36) is connected to the inlet end of the microfluidic drive pump (5).

3. The hermetically sealed microfluidic device containing a micro / nano sensing chip according to claim 1, characterized in that, The signal transmission end of the retractable detection electrode rod (34) is electrically connected to the signal processing device (6).

4. The hermetically sealed microfluidic device containing a micro / nano sensing chip according to claim 1, characterized in that, A sealing gasket is provided between the second liquid inlet (32) and the second liquid outlet (36) and the capillary tube (35), and the inner diameter of the sealing gasket is adapted to the outer diameter of the capillary tube (35), and the outer diameter of the sealing gasket is adapted to the inner diameter of the second liquid inlet (32) and the second liquid outlet (36).

5. The hermetically sealed microfluidic device containing a micro / nano sensing chip according to claim 1, characterized in that, The macrophages in the cell culture chamber (24) are placed on the upper part of the electrode plate module (22).

6. The hermetically sealed microfluidic device containing a micro / nano sensing chip according to claim 1, characterized in that, The inner wall of the cell culture chamber (24) is coated with a cell adhesion promoting layer.

7. The hermetically sealed microfluidic device containing a micro / nano sensing chip according to claim 6, characterized in that, The cell adhesion promoting layer is a collagen coating or a polylysine coating.

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