A method and system for predicting the activity of hydrocyclone sorted cells

Abstract

The present invention provides a method and system for predicting the activity of hydrocyclone sorting cells, including: obtaining the flow field parameters of each point in the near-wall area on each section of the hydrocyclone, calculating the shear stress of each point in the near-wall area on each section of the hydrocyclone; calculating the shear stress intensity parameter of the hydrocyclone based on the shear stress of each point; based on the calculated shear stress intensity parameter, using the correlation model of the shear stress intensity parameter and the underflow cell survival rate, predicting the underflow cell survival rate; wherein the shear stress is the sum of the viscous shear stress, the instantaneous shear stress, the shear stress at the fluid microelement scale generated by particle-particle collision, and the shear stress at the fluid microelement scale generated by particle-wall collision. The method realizes the rapid, low-cost and accurate prediction of the underflow cell survival rate after micro hydrocyclone sorting.

Description

Technical Field

[0001] The invention belongs to the technical field of cell activity prediction, and in particular relates to a method and system for predicting the activity of hydrocyclone sorted cells. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Micro hydrocyclones can effectively sort and retain mammalian cells, and have been increasingly used in monoclonal antibody production in recent years. Although the recovery rate of mammalian cells in micro hydrocyclones can reach more than 90%, the cell survival rates vary greatly under different structures and operating parameters of micro hydrocyclones (70% to 97%). The intensity of shear stress inside micro hydrocyclones is the main factor affecting cell activity. However, existing studies have ignored the shear stress generated by turbulence and particle-particle collisions, resulting in an extremely unclear mechanism for the generation of shear stress. Therefore, it is impossible to study and predict the effect of shear stress on cell survival after micro hydrocyclone sorting.

[0004] In addition, the survival rate of cells after micro-hydrocyclone sorting is usually measured experimentally. The cost of the experiment is relatively high, and it is easily limited by experimental conditions and has a certain lag. Summary of the invention

[0005] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a method and system for predicting the activity of hydrocyclone sorted cells, which associates the numerically calculated shear stress intensity parameters with the experimentally obtained underflow cell survival rate, and establishes a correlation model, thereby realizing fast, low-cost and accurate prediction of the underflow cell survival rate after micro hydrocyclone sorting.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A first aspect of the present invention provides a method for predicting the activity of hydrocyclone sorted cells, comprising:

[0008] Obtain the flow field parameters of each point in the near-wall region on each cross section of the hydrocyclone, and calculate the shear stress of each point in the near-wall region on each cross section of the hydrocyclone;

[0009] Calculating a shear stress intensity parameter of the hydrocyclone based on the shear stress at each point;

[0010] Based on the calculated shear stress intensity parameters, the survival rate of the underflow cells was predicted by using the correlation model between the shear stress intensity parameters and the underflow cell survival rate.

[0011] The shear stress is the sum of the viscous shear stress, the instantaneous shear stress, the shear stress at the fluid microelement scale caused by the collision between particles, and the shear stress at the fluid microelement scale caused by the collision between particles and the wall.

[0012] Furthermore, the calculation method of the shear stress intensity parameter of the hydrocyclone is:

[0013] Based on the shear stress at each point, the maximum shear stress of the near-wall area on each cross section of the hydrocyclone is selected;

[0014] The maximum shear stress in the near-wall area on all cross sections is averaged to obtain the shear stress intensity parameter of the hydrocyclone.

[0015] Furthermore, the distance between each point on the near-wall area and the central axis of the hydrocyclone is greater than or equal to the product of a set value and the radius of the hydrocyclone.

[0016] Furthermore, the method for constructing the correlation model between the shear stress intensity parameter and the survival rate of the underflow cell is:

[0017] Calculate the shear stress intensity of the micro hydrocyclone under several combinations of structural parameters and operating parameters to obtain several shear stress intensities;

[0018] The survival rates of underflow cells of the hydrocyclone under several combinations of structural parameters and operating parameters were obtained, and a correlation model between shear stress intensity parameters and underflow cell survival rates was established.

[0019] A second aspect of the present invention provides a system for predicting the activity of hydrocyclone sorted cells, comprising:

[0020] A shear stress calculation module is configured to: obtain flow field parameters of each point in the near-wall region on each cross section of the hydrocyclone, and calculate the shear stress of each point in the near-wall region on each cross section of the hydrocyclone;

[0021] A shear stress intensity parameter calculation module, configured to: calculate the shear stress intensity parameter of the hydrocyclone based on the shear stress at each point;

[0022] An underflow cell survival rate prediction module is configured to predict the underflow cell survival rate based on the calculated shear stress intensity parameter and using a correlation model between the shear stress intensity parameter and the underflow cell survival rate;

[0023] The shear stress is the sum of the viscous shear stress, the instantaneous shear stress, the shear stress at the fluid microelement scale caused by the collision between particles, and the shear stress at the fluid microelement scale caused by the collision between particles and the wall.

[0024] Furthermore, the shear stress intensity parameter calculation module is specifically configured as follows:

[0025] Based on the shear stress at each point, the maximum shear stress of the near-wall area on each cross section of the hydrocyclone is selected;

[0026] The maximum shear stress in the near-wall area on all cross sections is averaged to obtain the shear stress intensity parameter of the hydrocyclone.

[0027] Furthermore, the distance between each point on the near-wall area and the central axis of the hydrocyclone is greater than or equal to the product of a set value and the radius of the hydrocyclone.

[0028] Furthermore, it also includes an associated model building module, which is configured to:

[0029] Calculate the shear stress intensity of the micro hydrocyclone under several combinations of structural parameters and operating parameters to obtain several shear stress intensities;

[0030] The underflow cell survival rates of the hydrocyclone under several combinations of structural parameters and operating parameters were obtained, and a correlation model between shear stress intensity parameters and underflow cell survival rates was established.

[0031] A third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the method for predicting the activity of hydrocyclone-sorted cells as described above.

[0032] A fourth aspect of the present invention provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps in the method for predicting the activity of hydrocyclone sorted cells as described above are implemented.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention provides a method for predicting the activity of cells sorted by a hydrocyclone, which calculates the shear stress inside a micro hydrocyclone by a numerical simulation method, obtains the cell survival rate of the micro hydrocyclone under corresponding conditions by an experimental method, and associates the numerically calculated shear stress with the experimentally obtained cell survival rate to establish a correlation model, thereby quickly, cost-effectively and accurately predicting the cell survival rate after sorting by the micro hydrocyclone. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0036] Figure 1 This is a flow chart of a method for predicting the activity of hydrocyclone sorted cells according to the first embodiment of the present invention;

[0037] Figure 2 It is a schematic diagram of the structure of a micro hydrocyclone experimental system according to the first embodiment of the present invention. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0039] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0040] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0041] Embodiment 1

[0042] This embodiment provides a method for predicting the activity of hydrocyclone sorted cells, such as Figure 1 As shown, the specific steps include:

[0043] Step 1. Select 10 representative cross sections from the top to the bottom of the micro hydrocyclone, and obtain the flow field parameters of each point (one point is a calculation unit in the actual calculation) in the near wall area of ​​each cross section of the hydrocyclone (the distance between each point on the near wall area and the central axis of the hydrocyclone is greater than or equal to the product of the set value and the radius of the hydrocyclone, that is, r≥2 / 3R, where R is the radius of the hydrocyclone. For different points, the set value 2 / 3 remains unchanged, but because the diameter of the hydrocyclone from top to bottom is changing, R is changing).

[0044] Among them, the flow field parameters include dynamic viscosity μ, turbulent dissipation rate e, fluid density ρ f , the velocity u of the adjacent fluid element α , the distance y between adjacent fluid elements α , the velocity v of particle i i , the position x of particle i i , the particle-scale force f generated by the collision between particle i and other particles j ij , the vector d connecting the centroids of particles i and jij , particle-scale force generated by the collision between particle i and the wall The vector connecting the center of mass of particle i and the contact point of the wall and perpendicular to the contact surface Among them, α represents the number of the fluid element. Different structural parameters and operating parameters of the cyclone will affect these parameters, that is, a combination of structural parameters and operating parameters corresponds to a set of flow field parameters.

[0045] Among them, the hydrocyclone is a micro hydrocyclone.

[0046] Step 2: Calculate the shear stress at each point in the near-wall region of each cross section of the hydrocyclone.

[0047] Viscous shear stress due to time-averaged velocity gradient:

[0048]

[0049] Among them, τ vs is the viscous shear stress, μ is the dynamic viscosity, u is α ,y α are the speed and spacing of adjacent fluid elements (i.e., fluid calculation units), respectively.

[0050] The instantaneous shear stress caused by turbulence is:

[0051]

[0052] Where e is the turbulent dissipation rate, ρ f is the fluid density.

[0053] The CFD-DEM (computational fluid dynamics-discrete element method) method can obtain the particle-scale forces generated by particle-particle and particle-wall collisions, which need to be converted into shear stress at the fluid microelement scale through the weighted average time-space method and then accumulated with the shear stress at the fluid microelement scale shown in equations (1)-(2).

[0054] The shear stress of the fluid microelement scale generated by the collision between particles is as follows:

[0055]

[0056] The shear stress of the fluid microelement scale generated by the collision between the particle and the wall is shown in formula (4):

[0057]

[0058] Among them, h i =h(x i -x,st), x iis the position vector of particle i, x is the average position vector, S is the moment of particle i, and t is the average time; h = h(x, t) is the weighting function, x and t are the position vector and time respectively, and the weighting function satisfies the condition in the computational domain Ω (time and space domain) T is the time domain, t∈T=[T0,T1], T t =[T0+t,T1+t], T0 is the start time of the time domain, T1 is the end time of the time domain; v i ′ is the particle velocity v i The difference between the average velocity of the particles, f ij is the particle-scale force generated by the collision between particles i and j, d ij is the vector connecting the centroids of particles i and j, g ij is a coefficient determined by the weighted function of the force between particles i and j; is the particle-scale force generated by the collision between particle i and the wall, is the vector connecting the center of mass of particle i and the contact point of the wall and perpendicular to the contact surface, It is a coefficient determined by the weighted function of the force between particle i and the wall.

[0059] The above four shear stresses are calculated by the fluid dynamics software ANSYS Fluent, and all the shear stresses are accumulated to obtain the shear stress τ at each point in the near-wall area of ​​each cross section inside the micro hydrocyclone. s :

[0060] τ s =τ vs +τ ts +τ csp-p +τ csp-w (5)

[0061] That is, the shear stress is the sum of the viscous shear stress, the instantaneous shear stress, the shear stress at the fluid microelement scale caused by the collision between particles, and the shear stress at the fluid microelement scale caused by the collision between particles and the wall.

[0062] Step 3: Select the maximum shear stress max near the wall of each section of the hydrocyclone l (τ s , r≥2 / 3R), where l represents the lth section.

[0063] Step 4: Calculate the average of the maximum shear stress in the near-wall area on all cross sections to obtain the shear stress intensity parameter of the hydrocyclone, that is, take the average maximum shear stress in the near-wall area as the shear stress intensity parameter φ:

[0064]

[0065] Step 5: Based on the calculated shear stress intensity parameter, a correlation model between the shear stress intensity parameter and the underflow cell survival rate is used to predict the underflow cell survival rate.

[0066] Among them, the construction method of the correlation model between the shear stress intensity parameter and the survival rate of the bottom flow cell is as follows:

[0067] (1) Using steps 1-4, the shear stress intensity φ of the micro hydrocyclone under several combinations of structural parameters and operating parameters is calculated to obtain several shear stress intensities;

[0068] (2) Through Figure 2 The micro hydrocyclone cell separation experimental system shown in the figure obtains the underflow cell survival rate η of the hydrocyclone under several combinations of structural parameters and operating parameters:

[0069] The present invention adopts Figure 1 The micro hydrocyclone experimental system shown is used to separate and recover mammalian cells. The shake flask containing cells and culture medium is placed in a cell culture incubator to ensure sufficient oxygen supply and appropriate pH value, and cultured in a sterile, sealed environment. The structure and operating parameters of the micro hydrocyclone are set, and the culture fluid containing cells is fed to the two tangential inlets of the micro hydrocyclone through a peristaltic pump and a diverter valve. The cell culture fluid is separated by the micro hydrocyclone, the bottom flow at the lower end is the cell concentrate recovered by interception, and the overflow at the upper end is the culture fluid from which antibodies need to be extracted. The volumes are measured respectively, and the inlet, overflow and bottom flow product samples are mixed and stained with 0.2% trypan blue in a 1:1 ratio. Dead cells are stained dark blue by trypan blue due to ruptured cell membranes, while live cells are not stained, so dead cells and live cells can be distinguished. The cell viability in the inlet, overflow and bottom flow samples is determined by flow cytometry.

[0070] (3) Establish a correlation model between the shear stress intensity parameter φ and the bottom flow cell survival rate η: η~φ.

[0071] The present invention simultaneously considers the velocity gradient, turbulence, and shear stress generated by particle-particle collision, thereby obtaining a comprehensive multiphase flow shear stress field; by correlating the shear stress intensity parameters of the micro hydrocyclone with the activity of the sorted cells, a rapid, low-cost, and accurate prediction of the survival rate of the sorted cells can be achieved, thereby ensuring the survival rate of the cells sorted by the micro hydrocyclone, and effectively promoting the application of the micro hydrocyclone, a device with a simple structure, low cost, and high processing capacity, in the production of monoclonal antibodies.

[0072] Embodiment 2

[0073] This embodiment provides a system for predicting the activity of hydrocyclone-sorted cells, which specifically includes the following modules:

[0074] The correlation model building module is configured to: calculate the shear stress intensity of the micro hydrocyclone under several combinations of structural parameters and operating parameters to obtain several shear stress intensities; obtain the underflow cell survival rate of the hydrocyclone under several combinations of structural parameters and operating parameters, and establish a correlation model between the shear stress intensity parameter and the underflow cell survival rate.

[0075] A shear stress calculation module is configured to: obtain flow field parameters of each point in the near-wall region on each cross section of the hydrocyclone, and calculate the shear stress of each point in the near-wall region on each cross section of the hydrocyclone;

[0076] A shear stress intensity parameter calculation module, configured to: calculate the shear stress intensity parameter of the hydrocyclone based on the shear stress at each point;

[0077] An underflow cell survival rate prediction module is configured to predict the underflow cell survival rate based on the calculated shear stress intensity parameter and using a correlation model between the shear stress intensity parameter and the underflow cell survival rate;

[0078] The shear stress is the sum of the viscous shear stress, the instantaneous shear stress, the shear stress at the fluid microelement scale caused by the collision between particles, and the shear stress at the fluid microelement scale caused by the collision between particles and the wall.

[0079] Among them, the shear stress intensity parameter calculation module is specifically configured as follows:

[0080] Based on the shear stress at each point, the maximum shear stress of the near-wall area on each cross section of the hydrocyclone is selected;

[0081] The maximum shear stress in the near-wall area on all cross sections is averaged to obtain the shear stress intensity parameter of the hydrocyclone.

[0082] The distance between each point on the near-wall area and the central axis of the hydrocyclone is greater than or equal to the product of a set value and the radius of the hydrocyclone.

[0083] It should be noted here that each module in this embodiment corresponds to each step in Example 1 one by one, and the specific implementation process is the same, which will not be repeated here.

[0084] Embodiment 3

[0085] This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the steps in the method for predicting the activity of hydrocyclone-sorted cells as described in the first embodiment above are implemented.

[0086] Embodiment 4

[0087] This embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps in the method for predicting the activity of hydrocyclone-sorted cells as described in the first embodiment above are implemented.

[0088] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0089] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0090] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0091] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0092] A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for predicting the activity of hydrocyclone sorted cells, characterized in that: include: Obtain the flow field parameters of each point in the near-wall region on each cross section of the hydrocyclone, and calculate the shear stress of each point in the near-wall region on each cross section of the hydrocyclone; Calculating a shear stress intensity parameter of the hydrocyclone based on the shear stress at each point; Based on the calculated shear stress intensity parameters, the survival rate of the underflow cells was predicted by using the correlation model between the shear stress intensity parameters and the underflow cell survival rate. The shear stress is the sum of the viscous shear stress, the instantaneous shear stress, the shear stress at the fluid microelement scale caused by the collision between particles, and the shear stress at the fluid microelement scale caused by the collision between particles and the wall.

2. A method for predicting the activity of hydrocyclone sorted cells according to claim 1, characterized in that: The calculation method of the shear stress intensity parameter of the hydrocyclone is: Based on the shear stress at each point, the maximum shear stress of the near-wall area on each cross section of the hydrocyclone is selected; The maximum shear stress in the near-wall area on all cross sections is averaged to obtain the shear stress intensity parameter of the hydrocyclone.

3. A method for predicting the activity of hydrocyclone sorted cells according to claim 1, characterized in that: The distance between each point on the near-wall area and the central axis of the hydrocyclone is greater than or equal to the product of a set value and the radius of the hydrocyclone.

4. A method for predicting the activity of hydrocyclone sorted cells as claimed in claim 1, characterized in that: The method for constructing the correlation model between the shear stress intensity parameter and the survival rate of the bottom flow cell is: Calculate the shear stress intensity of the micro hydrocyclone under several combinations of structural parameters and operating parameters to obtain several shear stress intensities; The survival rates of underflow cells of the hydrocyclone under several combinations of structural parameters and operating parameters were obtained, and a correlation model between shear stress intensity parameters and underflow cell survival rates was established.

5. A system for predicting the activity of hydrocyclone sorted cells, characterized in that: include: A shear stress calculation module is configured to: obtain flow field parameters of each point in the near-wall region on each cross section of the hydrocyclone, and calculate the shear stress of each point in the near-wall region on each cross section of the hydrocyclone; A shear stress intensity parameter calculation module, configured to: calculate the shear stress intensity parameter of the hydrocyclone based on the shear stress at each point; An underflow cell survival rate prediction module is configured to predict the underflow cell survival rate based on the calculated shear stress intensity parameter and using a correlation model between the shear stress intensity parameter and the underflow cell survival rate; The shear stress is the sum of the viscous shear stress, the instantaneous shear stress, the shear stress at the fluid microelement scale caused by the collision between particles, and the shear stress at the fluid microelement scale caused by the collision between particles and the wall.

6. A system for predicting the activity of hydrocyclone sorted cells as claimed in claim 5, characterized in that: The shear stress intensity parameter calculation module is specifically configured as follows: Based on the shear stress at each point, the maximum shear stress of the near-wall area on each cross section of the hydrocyclone is selected; The maximum shear stress in the near-wall area on all cross sections is averaged to obtain the shear stress intensity parameter of the hydrocyclone.

7. A system for predicting the activity of hydrocyclone sorted cells as claimed in claim 5, characterized in that: The distance between each point on the near-wall area and the central axis of the hydrocyclone is greater than or equal to the product of a set value and the radius of the hydrocyclone.

8. A system for predicting the activity of hydrocyclone sorted cells as claimed in claim 5, characterized in that: Also included is an association model building module, which is configured to: Calculate the shear stress intensity of the micro hydrocyclone under several combinations of structural parameters and operating parameters to obtain several shear stress intensities; The survival rates of underflow cells of the hydrocyclone under several combinations of structural parameters and operating parameters were obtained, and a correlation model between shear stress intensity parameters and underflow cell survival rates was established.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps in a method for predicting the activity of hydrocyclone-sorted cells as claimed in any one of claims 1 to 4 are implemented.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps in the method for predicting the activity of hydrocyclone-sorted cells are implemented as described in any one of claims 1 to 4.

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