Device for separating different components in blood based on three-dimensional microfluidics

Abstract

The utility model provides a device for separating different components in blood based on three-dimensional microfluidics, and the device is characterized in that the device comprises a three-dimensional microfluidics structure, the three-dimensional microfluidics structure comprises a spiral flow channel which is arranged in a spiral descending manner, and the spiral flow channel is communicated with the three-dimensional microfluidics structure; the spiral radius of the spiral flow channel is gradually increased or gradually reduced along the spiral descending direction; the outlet structure is connected with the three-dimensional micro-fluidic structure, comprises a main sample outlet and at least one primary sample outlet, and is designed into the three-dimensional micro-fluidic structure which spirally descends through a continuous catheter, so that the limitation of an existing two-dimensional micro-fluidic chip is broken through, and the effect of separating different components in blood more quickly and efficiently is achieved.

Description

Technical Field

[0001] The present application relates to the field of microfluidics technology, and in particular to a device for separating different components in blood based on three-dimensional microfluidics. Background Art

[0002] With the rapid progress of contemporary medical technology, microfluidics, as a revolutionary platform, has shown unprecedented potential in the field of blood analysis and separation. It not only breaks through the limitations of traditional blood processing technology, but also opens up new paths for precision medicine, instant diagnosis and basic scientific research. Microfluidics is used to separate different components of blood. It can directly load whole blood onto the machine without damaging the different components of blood during the separation process. It also has the characteristics of small sample usage, high separation efficiency, short processing time, and no need for density gradient centrifugation. The various components obtained, such as exosomes, serum, red blood cells, white blood cells, circulating tumor cells, fetal nucleated red blood cells, etc., meet clinical requirements and can be directly used in different downstream applications. Therefore, it has been widely used in scientific research and clinical fields.

[0003] Most of the microfluidic chips on the market currently use etching of the corresponding flow channels in the base layer, or injection molding of polymer materials into chips with specific pipeline designs. Although chips with specific functions can be mass-produced, these two-dimensional structural designs are often limited by the status quo of processing technology and material science. At present, the main method is to connect chips of different layers into one by means of hot pressing, gluing, bonding, etc., and the multi-layer structure bonding process may cause irreversible effects on the flow channels of each layer. At the same time, the bonding accuracy of each layer is very high, which undoubtedly increases the manufacturing cost and technical difficulty, and limits the design freedom and the development of three-dimensional complex systems.

[0004] In view of this, developing new microfluidic structure design and manufacturing technologies to overcome the limitations of current two-dimensional structures has become the key to promoting further development in this field. Utility Model Content

[0005] The present application provides a device for separating different components in blood based on three-dimensional microfluidics. The continuous catheter is designed as a spirally descending three-dimensional microfluidic structure to break through the limitations of existing two-dimensional microfluidic chips and achieve faster and more efficient separation of different components in blood.

[0006] To achieve the above objectives, the present technical solution provides a device for separating different components in blood based on three-dimensional microfluidics, comprising: a device for separating different components in blood based on three-dimensional microfluidics, characterized in that it comprises: a three-dimensional microfluidic structure, wherein the three-dimensional microfluidic structure comprises a spiral flow channel arranged in a spiral descent, and the spiral radius of the spiral flow channel gradually increases or decreases in the direction of the spiral descent; an outlet structure connected to the three-dimensional microfluidic structure, wherein the outlet structure comprises a main sample outlet and at least one primary sample outlet.

[0007] Compared with the prior art, this technical solution has the following characteristics and effects:

[0008] 1. The flow channel formed by the continuous catheter is designed as a spirally descending three-dimensional microfluidic structure, and the spiral radius of the spiral three-dimensional microfluidic structure gradually changes as the spiral descends. Based on the principle of inertial aggregation, different components in the blood can be separated more quickly to achieve three-dimensional microfluidics, so as to achieve the separation of different components in the blood.

[0009] 2. The device for separating different components in blood based on three-dimensional microfluidics in this scheme is designed as a three-dimensional structure, breaking through the limitations of two-dimensional microfluidic chips, increasing space utilization efficiency, and having greater space utilization; at the same time, due to the structure of a continuous catheter, it can avoid the influence of misalignment and flow channel interference that may be caused by the bonding process of traditional microfluidic chips with different layers, and can better achieve the separation of different components in the blood. It also has the advantages of being easier to manufacture and more robust.

[0010] 3. The continuous catheter of this scheme can be made of any type of material, and the functional layer can be modified inside the catheter according to actual needs. On the basis of inertial focusing, the charged properties of the catheter wall can be adjusted by modifying the functional layer, thereby reducing non-specific cell binding to the catheter wall and improving the separation and recovery effect of different components in the blood.

[0011] 4. Designing three-dimensional microfluidic structures with different spiral radii and spiral shapes according to the blood components that need to be separated can not only be used for the separation of circulating tumor cells, but also for the separation of red blood cells and white blood cells in the blood, or the separation of exosomes and cells, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The drawings described herein are used to provide further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0013] Figure 1 This is a schematic diagram of the structure of the device for separating different components in blood based on three-dimensional microfluidics provided in this scheme.

[0014] Figure 2 This is a schematic diagram of another perspective of the device for separating different components in blood based on three-dimensional microfluidics provided in this scheme.

[0015] Figure 3 This is a schematic diagram of the outlet structure of the device for separating different components in blood based on three-dimensional microfluidics provided in this scheme.

[0016] Figure 4 Figure 2 is a staining image of isolated circulating tumor cells.

[0017] In the attached picture:

[0018] 10-three-dimensional microfluidic structure, 11-spiral flow channel, 111-blood inlet, 112-flow channel outlet, 20-outlet structure, 21-connecting port, 22-main outlet, 23-secondary outlet. DETAILED DESCRIPTION

[0019] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with one or more embodiments of this specification. Instead, they are merely examples of devices and methods consistent with some aspects of one or more embodiments of this specification as detailed in the appended claims.

[0020] It should be noted that: in other embodiments, the steps of the corresponding method are not necessarily performed in the order shown and described in this specification. In some other embodiments, the steps included in the method may be more or less than those described in this specification. In addition, a single step described in this specification may be decomposed into multiple steps for description in other embodiments; and multiple steps described in this specification may be combined into a single step for description in other embodiments.

[0021] Embodiment 1

[0022] This scheme provides a device based on three-dimensional microfluidics for separating different components in blood, which uses the inertial focusing principle to separate different components in blood, such as circulating tumor cells, exosomes, leukocytes, etc.

[0023] Regarding the inertial aggregation principle mentioned here: when the fluid of randomly scattered fine particles or cells flows into a straight pipe in a low Reynolds number laminar flow, after flowing for a certain distance, these cells or particles will stably gather in a concentric ring position at a fixed distance from the center of the pipe, so the separation of different components in the blood can be achieved by designing different flow channel shapes or regulating key factors such as the flow state of the fluid. For example, circulating tumor cells, as one of the blood components, have the characteristics of larger cells and larger nucleocytoplasm ratio; exosomes are tiny vesicles released by cells, and their diameter is usually between 40 and 160nm; red blood cells have a diameter of 6-9.5μm, an average of 7.2μm, no nucleus, and the cytoplasm is full of hemoglobin; white blood cells are colorless nucleated spherical cells, which are larger in volume than red blood cells and can deform. These components can be separated by inertial focusing, so this scheme is also based on the inertial aggregation principle to design a device based on three-dimensional microfluidics to separate different components in blood.

[0024] like Figures 1 to 3 As shown, the device for separating different components in blood based on three-dimensional microfluidics provided in this scheme includes:

[0025] A three-dimensional microfluidic structure 10, wherein the three-dimensional microfluidic structure 10 comprises a spiral flow channel 11 arranged in a spiral downward direction, and the spiral radius of the spiral flow channel 11 gradually increases or decreases along the spiral downward direction;

[0026] The outlet structure 20 is connected to the three-dimensional microfluidic structure 10 , wherein the outlet structure 20 includes a main sample outlet 22 and at least one secondary sample outlet 23 .

[0027] In some embodiments, the spiral flow channel 11 is a continuous conduit arranged in a spiral direction. In other words, the blood inlet 111 and the flow channel outlet 112 of the spiral flow channel 11 are connected to each other through a continuous conduit, wherein the blood inlet 111 is arranged at the starting position of the spiral descent, and the flow channel outlet 112 is arranged at the end position of the spiral descent. It is precisely because the spiral flow channel 11 of the present solution is obtained by spirally arranging a continuous conduit that the dead volume or fluid disturbance that may be caused by the connection between the flow channels in the traditional multi-layer structure can be avoided, thereby improving the separation efficiency and sample recovery rate, and cleverly utilizing the spiral geometric shape to achieve efficient and gentle separation of different components in blood or other biological fluids.

[0028] In this solution, the change rate of the spiral flow channel 11 can be designed to accurately control the flow rate, shear force and retention time of the fluid. In particular, when the spiral radius of the spiral flow channel 11 gradually increases in the direction of spiral descent, the linear velocity of the fluid can be gradually reduced, which is conducive to gravity-dependent separation; when the spiral radius of the spiral flow channel 11 gradually decreases in the direction of spiral descent, the vortex effect of the fluid can be enhanced, which is conducive to separation based on inertia or centrifugal force.

[0029] In some embodiments, the spiral flow channel 11 is arranged to spirally descend along the same axis. In other words, the spiral flow channel 11 gradually extends downward along an axis from a starting point, and at the same time winds around the axis in a spiral form to form a continuous channel structure, ensuring that the fluid experiences a consistent and controllable mechanical environment when passing through the flow channel, which is crucial for biomedical applications that require precise control of fluid dynamics conditions.

[0030] In some embodiments, the inner diameter of the spiral flow channel 11 of the three-dimensional microfluidic structure 10 is uniform. This has the advantage of ensuring that the fluid experiences consistent fluid dynamic conditions, including flow rate, shear force distribution, etc., when passing through the entire spiral flow channel, which helps to reduce cell damage or separation efficiency fluctuations caused by sudden changes in fluid dynamic parameters; and the uniform inner diameter can ensure that different components are stably separated according to their physical properties (such as size, density or charge), avoiding the interference of velocity differences or eddy effects on the separation effect caused by changes in flow channel size, thereby improving separation purity.

[0031] In other embodiments, the three-dimensional microfluidic structure 10 includes at least two spiral flow channels 11, and at least two spiral flow channels 11 are connected to each other. In other words, the three-dimensional microfluidic structure 10 of this solution may include multiple spiral flow channels 11 to achieve separation of different components.

[0032] It should be noted that the material of the spiral flow channel 11 of the present solution is not limited, and the material can be any type of conduit, polymer material, biological pore, etc. In addition, the spiral flow channel 11 of the present solution is provided with a functional layer inside, wherein the functional layer includes but is not limited to one or a combination of a hydrophilic functional layer, a hydrophobic functional layer, an adhesive functional layer, and a bioaffinity functional layer, so as to achieve the function of capturing specific components.

[0033] The flow channel outlet 112 of the spiral flow channel 11 of the present solution is connected to the outlet structure 20 , and the connecting port 21 of the outlet structure 20 is connected to the flow channel outlet 112 of the spiral flow channel 11 , so that the blood components descending through the spiral flow channel can flow out from different outlet directions of the outlet structure 20 .

[0034] In order to achieve a rapid separation effect, the outlet directions of the primary sample outlet 22 and the secondary sample outlet 23 of the outlet structure 20 are arranged obliquely downward relative to the connecting port 21 , where downward arrangement means a direction away from the three-dimensional microfluidic structure.

[0035] In some embodiments, the main sample outlet 22 , the secondary sample outlet 23 and the connecting port 21 are connected to form a Y-shape, wherein the main components to be separated flow out from the main sample outlet 22 , and other secondary components to be separated flow out from the secondary sample outlet 22 .

[0036] It should be noted that the size of the cell components collected by the sample outlet close to the three-dimensional microfluidic structure 10 is larger than the cell components collected by the sample outlet far from the three-dimensional microfluidic structure. In other words, when the main sample outlet 22 is used to collect large-sized blood components, the main sample outlet 22 is the sample outlet close to one side of the three-dimensional microfluidic structure.

[0037] In the embodiment of the present solution, the connection port 21 of the outlet structure 20 is separated from or integrally connected to the flow channel outlet 112 of the spiral flow channel 11. When the connection port 21 of the outlet structure 20 is separated from and connected to the flow channel outlet 112 of the spiral flow channel 11, the connection port 21 and the flow channel outlet 112 are connected via a Luer connector or other structure, and it is necessary to reduce the difference in the inner diameters of the two during the connection process to avoid changes in the laminar flow phenomenon caused by changes in the inner diameters.

[0038] In some specific embodiments, the spiral flow channel 11 of the three-dimensional microfluidic structure 10 is designed as a continuous conduit with a spiral radius gradually increasing in the direction of spiral descent, the inner diameter of the spiral flow channel 11 is 0.4 mm, and the outlet structure 20 includes a main sample outlet 22 and a secondary sample outlet 23, wherein the diameters of the main sample outlet 22 and the secondary sample outlet 23 are both 0.4 mm.

[0039] In addition, the device for separating different components in blood based on three-dimensional microfluidics also includes a detection structure (not shown in the figure), which is arranged upstream of the blood sample inlet 111 of the three-dimensional microfluidic structure 10 to provide pressure to inject the blood sample to be tested into the three-dimensional microfluidic structure 10 at a stable flow rate. In some embodiments, the detection structure is selected as a pressure pump or a peristaltic pump.

[0040] In order to verify the separation effect of the device based on three-dimensional microfluidics for separating different components in blood,

[0041] This scheme uses blood from patients with advanced breast cancer. Under the control of a syringe pump, the blood is added to the three-dimensional microfluidic structure 10 within a flow rate range. CTCs are collected from the main sample outlet 22 close to the three-dimensional microfluidic structure 10 to achieve CTC separation. Subsequently, circulating tumor cells are successfully observed through centrifugation, concentration, smearing, fixation, and staining (CD45-AF488 for white blood cell staining, EpCAM-AF594 for CTC staining, and DAPI for cell nucleus staining). The observation results are as follows: Figure 4 shown.

[0042] This solution uses healthy human blood, adds the blood into the three-dimensional microfluidic structure 10 within a flow rate range determined by controlling the flow rate through a peristaltic pump, and collects red blood cells from the main sample outlet 22 close to the three-dimensional microfluidic structure 10 to achieve red blood cell separation.

[0043] This protocol also uses a mixture of guinea pig red blood cells and Jurkat cells to simulate blood, and successfully achieves the separation of red blood cells and Jurkat cells.

[0044] Those skilled in the art should understand that the technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A device for separating different components in blood based on three-dimensional microfluidics, characterized in that: include: A three-dimensional microfluidic structure (10), wherein the three-dimensional microfluidic structure (10) comprises a spiral flow channel (11) arranged in a spiral downward direction, and the spiral radius of the spiral flow channel (11) gradually increases or decreases along the spiral downward direction; An outlet structure (20) connected to a three-dimensional microfluidic structure (10), wherein the outlet structure (20) comprises a main sample outlet (22) and at least one secondary sample outlet (23).

2. The device for separating different components in blood based on three-dimensional microfluidics according to claim 1, characterized in that: A continuous conduit is connected between the blood sampling port (111) and the flow channel outlet (112) of the spiral flow channel (11).

3. The device for separating different components in blood based on three-dimensional microfluidics according to claim 1, characterized in that: The spiral flow channel (11) is arranged to descend in a spiral along the same axis.

4. The device for separating different components in blood based on three-dimensional microfluidics according to claim 1, characterized in that: The inner diameter of the spiral flow channel (11) of the three-dimensional microfluidic structure (10) is uniform.

5. The device for separating different components in blood based on three-dimensional microfluidics according to claim 1, characterized in that: The three-dimensional microfluidic structure (10) comprises at least two spiral flow channels (11), and at least two spiral flow channels (11) are connected to each other.

6. The device for separating different components in blood based on three-dimensional microfluidics according to claim 1, characterized in that: A functional layer is arranged inside the spiral flow channel (11), wherein the functional layer comprises one or a combination of a hydrophilic functional layer, a hydrophobic functional layer, an adhesive functional layer and a bioaffinity functional layer.

7. The device for separating different components in blood based on three-dimensional microfluidics according to claim 1, characterized in that: The connection port (21) of the outlet structure (20) is connected to the flow channel outlet (112) of the spiral flow channel (11).

8. The device for separating different components in blood based on three-dimensional microfluidics according to claim 1, characterized in that: The outlet directions of the main sample outlet (22) and the secondary sample outlet (23) of the outlet structure (20) are arranged obliquely downward relative to the connecting port (21).

9. The device for separating different components in blood based on three-dimensional microfluidics according to claim 1, characterized in that: The connection port (21) of the outlet structure (20) is separated from or integrally connected to the flow channel outlet (112) of the spiral flow channel (11).

10. The device for separating different components in blood based on three-dimensional microfluidics according to claim 1, characterized in that: The detection structure comprises a detection structure which is arranged upstream of a blood sample inlet (111) of a three-dimensional microfluidic structure (10) and is used to provide pressure to inject a blood sample to be tested into the three-dimensional microfluidic structure (10) at a stable flow rate.

Images