Simulation device, simulation system, and simulation method

Abstract

A simulation device (14) comprises a simulation execution unit (142) that executes a simulation pertaining to changes in the concentration of protein in an inner circulation passage (first circulation flow passage (58)) which occur in association with cell proliferation under prescribed culture conditions by using at least: the supply rate, which is the rate at which the concentration of protein in the inner circulation passage changes due to the supply of a culture medium into the inner circulation passage; the exchange rate, which is the rate at which the concentration of protein in the inner circulation passage changes due to the inflow and outflow of the culture medium between the inside and outside of an inner hole via a hollow fiber membrane (40); and the deterioration rate, which is the rate at which the concentration of protein in the inner circulation passage changes due to the deterioration of protein.

Description

Simulation device, simulation system, and simulation method

[0001] The present invention relates to a simulation device, a simulation system, and a simulation method for simulating cell growth in a cell culture device.

[0002] JP 2020-171241 A discloses a cell culture device. The cell culture device includes a bioreactor, a supply unit, a recovery unit, and multiple flow paths. Some of the flow paths form a circulation path together with the bioreactor. The supply unit supplies a cell-containing liquid and a culture medium (culture solution) to the bioreactor. The bioreactor cultures cells. During cell culture, a portion of the culture medium (first culture medium) circulates through the circulation path. During cell culture, a portion of the culture medium (second culture medium) is discharged as waste liquid. The cultured cells are recovered by the recovery unit.

[0003] Japanese Patent Application Laid-Open No. 2020-171241

[0004] For cell culture, it is important to supply nutrients (glucose, glutamine, various amino acids, etc.), gases (oxygen, carbon dioxide, etc.), and waste products (lactic acid, ammonia, etc.). Furthermore, it is also important to supply proteins. For this reason, bovine serum (including albumin and growth factors), growth factors, cytokines, etc. are added to the culture medium.

[0005] If cells are supplied with insufficient protein, they will not grow. On the other hand, if too much protein is supplied to cells, cell growth will be inhibited. Furthermore, the unit price of some proteins (growth factors, cytokines, etc.) is expensive. For these reasons, it is desirable to appropriately control the amount of protein supplied to cells.

[0006] The present invention aims to solve the above-mentioned problems.

[0007] (1) A first invention is a simulation device that performs a simulation of cell growth in a cell culture device that supplies a medium containing a protein to an inner circulation path, which is a circulation path including an inner hole of a cylindrical hollow fiber membrane, and cultures cells in the inner hole. The simulation device includes a simulation execution unit that performs the simulation of changes in the concentration of the protein in the inner circulation path due to cell growth under specified culture conditions using at least a supply rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to the supply of medium to the inner circulation path; an exchange rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to the inflow and outflow of medium between the inside and outside of the inner hole via the hollow fiber membrane; and a degradation rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to degradation of the protein.

[0008] Due to the relationship between the molecular weight cutoff of the hollow fiber membrane and the size of the protein, the behavior of the protein diffusing into and out of the cylindrical hollow fiber membrane varies depending on the type of protein. In the first invention, a simulation is performed using not only the supply rate and degradation rate but also the exchange rate. Therefore, according to the first invention, the accuracy of the simulation of changes in protein concentration can be improved. By reflecting the results of the simulation in actual culture, users can appropriately control the amount of protein.

[0009] (2) The simulation device according to the above item (1) may further include a display control unit that displays information corresponding to the concentration change obtained by the simulation on a display unit.

[0010] (3) In the simulation device described in the above item (1) or (2), the simulation execution unit may perform the simulation of the change in concentration of the protein in the inner circulation path by further using a consumption rate, which is a rate at which the concentration of the protein in the inner circulation path changes due to consumption of the protein by cells.

[0011] According to the configuration of the above item (3), the accuracy of the simulation of the change in protein concentration can be further improved.

[0012] (4) In the simulation device described in any one of items (1) to (3) above, when a portion of the culture medium is discarded through the inner circulation path during cell cultivation, the simulation execution unit may perform the simulation of the change in concentration of the protein in the inner circulation path by further using a discard rate, which is the rate at which the concentration of the protein in the inner circulation path changes due to the discard of a portion of the culture medium through the inner circulation path.

[0013] According to the configuration of the above item (4), the accuracy of the simulation of the change in protein concentration can be further improved.

[0014] (5) In the simulation device described in any one of items (1) to (4) above, the simulation execution unit may perform the simulation of the change in concentration of the protein in the inner circulation path by further using an adsorption rate, which is the proportion of the protein that cannot be consumed by cells due to adsorption, aggregation, and deposition of the protein in at least one of the inside of the inner circulation path and the inside of the outer circulation path, which is a circulation path that includes a region between the hollow fiber membrane and a housing that accommodates the hollow fiber membrane.

[0015] According to the configuration of the above item (5), the accuracy of the simulation of the change in protein concentration can be further improved.

[0016] (6) In the simulation device described in any one of items (1) to (5) above, the cell culture device may be capable of supplying a medium that does not contain the protein to an outer circulation path, which is a circulation path that includes a region between the hollow fiber membrane and a housing that accommodates the hollow fiber membrane.

[0017] (7) In the simulation device according to any one of items (1) to (6) above, when culturing adherent cells, the cell culture device may discard the culture medium through a waste liquid flow path connected to the inner circulation path.

[0018] (8) In the simulation device described in the above item (6), when culturing suspension cells, the cell culture device may discard the culture medium through a waste liquid flow path connected to the outer circulation path.

[0019] (9) In the simulation device described in any one of items (1) to (8) above, the cell culture device includes an outer circulation path that is a circulation path that includes the interior of the inner circulation path and an area between the hollow fiber membrane and a housing that accommodates the hollow fiber membrane, and when a portion of the culture medium is discarded through the outer circulation path during cell culture, the simulation execution unit may perform the simulation of the change in the concentration of the protein in the outer circulation path due to cell growth under the culture conditions using at least a discard rate, which is a rate at which the concentration of the protein in the outer circulation path changes due to the discard of a portion of the culture medium through the outer circulation path, the exchange rate, and the deterioration rate.

[0020] (10) A second invention is a simulation system that performs a simulation of cell growth in a cell culture device that supplies a medium containing a protein to an inner circulation path, which is a circulation path including an inner hole of a cylindrical hollow fiber membrane, and cultures cells in the inner hole. The simulation system includes a simulation execution unit that performs the simulation of changes in the concentration of the protein in the inner circulation path due to cell growth under specified culture conditions using at least a supply rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to the supply of medium to the inner circulation path; an exchange rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to the inflow and outflow of medium between the inside and outside of the inner hole via the hollow fiber membrane; and a degradation rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to degradation of the protein; and a display control unit that displays information corresponding to the concentration changes obtained by the simulation on a display unit.

[0021] In the second invention, a simulation is performed using not only the supply rate and degradation rate but also the exchange rate. Therefore, according to the second invention, the accuracy of the simulation of protein concentration changes can be improved. By reflecting the results of the simulation in the actual culture, the user can appropriately control the amount of protein.

[0022] (11) A third invention is a simulation method for performing a simulation of cell growth in a cell culture device in which a medium containing a protein is supplied to an inner circulation path, which is a circulation path including an inner hole of a cylindrical hollow fiber membrane, and cells are cultured in the inner hole, the method including a simulation step of performing the simulation of changes in the concentration of the protein in the inner circulation path due to cell growth under specified culture conditions using at least a supply rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to the supply of medium to the inner circulation path; an exchange rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to the inflow and outflow of medium between the inside and outside of the inner hole via the hollow fiber membrane; and a degradation rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to degradation of the protein.

[0023] In the third invention, a simulation is performed using not only the supply rate and degradation rate but also the exchange rate. Therefore, according to the third invention, the accuracy of the simulation of protein concentration changes can be improved. By reflecting the results of the simulation in actual culture, users can appropriately control the amount of protein.

[0024] (12) The simulation method according to the above item (11) may further include a display step of displaying information corresponding to the concentration change obtained by the simulation on a display unit.

[0025] (13) In the simulation method according to the above item (11) or (12), the simulation step may further use a consumption rate, which is a rate at which the concentration of the protein changes in the inner circulation path due to consumption of the protein by cells, to perform the simulation of the change in the concentration of the protein in the inner circulation path.

[0026] According to the configuration of the above item (13), the accuracy of the simulation of the change in protein concentration can be further improved.

[0027] (14) In the simulation method according to any one of items (11) to (13), when a portion of the culture medium is discarded through the inner circulation path during cell culture, the simulation step may further use a discard rate, which is a rate at which the concentration of the protein changes in the inner circulation path due to the discarding of a portion of the culture medium through the inner circulation path, to perform the simulation of the change in concentration of the protein in the inner circulation path.

[0028] According to the configuration of the above item (14), the accuracy of the simulation of the change in protein concentration can be further improved.

[0029] (15) In the simulation method according to any one of items (11) to (14), in the simulation step, the simulation of the change in concentration of the protein in the inner circulation path may be performed by further using an adsorption rate, which is the proportion of the protein that cannot be consumed by cells due to adsorption, aggregation, and deposition of the protein in at least one of the inside of the inner circulation path and the inside of the outer circulation path, which is a circulation path that includes a region between the hollow fiber membrane and a housing that accommodates the hollow fiber membrane.

[0030] According to the configuration of the above item (15), the accuracy of the simulation of the change in protein concentration can be further improved.

[0031] (16) In the simulation method according to any one of items (11) to (15), the cell culture device may be capable of supplying the protein-free medium to an outer circulation path, which is a circulation path including a region between the hollow fiber membrane and a housing that accommodates the hollow fiber membrane.

[0032] (17) In the simulation method according to any one of items (11) to (16), when culturing adherent cells, the cell culture device may discard the culture medium through a waste liquid flow path connected to the inner circulation path.

[0033] (18) In the simulation device described in the above item (16), when culturing suspension cells, the cell culture device may discard the culture medium through a waste liquid flow path connected to the outer circulation path.

[0034] (19) In the simulation method described in any one of items (11) to (18), the cell culture device includes an outer circulation path that is a circulation path that includes the interior of the inner circulation path and a region between the hollow fiber membrane and a housing that accommodates the hollow fiber membrane, and when a portion of the culture medium is discarded through the outer circulation path during cell culture, the simulation step may perform the simulation of the change in the concentration of the protein in the outer circulation path due to cell growth under the culture conditions using at least a discard rate, which is a rate at which the concentration of the protein in the outer circulation path changes due to the discard of a portion of the culture medium through the outer circulation path, the exchange rate, and the deterioration rate.

[0035] According to the present invention, the amount of protein can be appropriately controlled.

[0036] FIG. 1 is a diagram showing the configuration of a cell culture system. FIG. 2 is a diagram showing the configuration of a control unit of a cell culture device. FIG. 3 is a diagram showing the configuration of a simulation device. FIG. 4 is a table showing parameter information. FIG. 5 is a diagram showing an input screen displayed on the display unit. FIG. 6 is a diagram showing a growth data screen displayed on the display unit. FIG. 7 is a diagram showing a feedback condition screen displayed on the display unit. FIG. 8 is a diagram showing a result screen displayed on the display unit. FIG. 9 is a diagram showing a result screen displayed on the display unit. FIG. 10 is a flowchart showing the flow of a cell culture method performed using a cell culture system. FIG. 11 is a diagram showing the operation of the cell culture device when culturing cells in the first culture form. FIG. 12 is a diagram showing the operation of the cell culture device when collecting cells in the first culture form. FIG. 13 is a diagram showing the operation of the cell culture device when culturing cells in the second culture form. FIG. 14 is a diagram showing the operation of the cell culture device when culturing cells in the third culture form. FIG. 15 is a diagram showing the operation of the cell culture device when culturing cells in the fourth culture form. FIG. 16 is a flowchart showing the flow of cell culture performed using the cell culture device. FIG. 17 is a diagram showing the operation of the cell culture device when culturing cells. FIG. 18 is a diagram showing the operation of the cell culture device when cells are detached. FIG. 19 is a diagram showing the operation of the cell culture device when cells are recovered. FIG. 20 is a diagram showing the configuration of a simulation system. FIG. 21 is a table showing specific examples of numerical values ​​of parameter information. FIG. 22 is a table showing culture conditions. FIG. 23 is a table showing culture conditions. FIG. 24 is a table showing culture conditions. FIG. 25 is a graph showing the transition of protein concentration in the first circulation flow path. FIG. 26 is a graph showing the transition of protein concentration in the first circulation flow path. FIG. 27 is a graph showing the transition of protein concentration in the first circulation flow path. FIG. 28 is a table showing culture conditions. FIG. 29 is a graph showing the transition of protein concentration in the first circulation flow path.

[0037] In cell culture using hollow fiber membranes, due to the relationship between the membrane cutoff size and the molecular weight of proteins, proteins smaller than the membrane cutoff size leak out during the culture period, making it difficult to accurately determine the protein concentration.

[0038] Furthermore, the cells to be cultured include, for example, adherent cells that grow using the hollow fiber membrane as a scaffold, and suspension cells that grow floating within the hollow fiber membrane. To culture cells, a cell culture form appropriate for the cell type is required. To accurately grasp the protein concentration, a method for predicting changes in protein concentration depending on the cell culture form is required.

[0039] Furthermore, depending on the cell growth state, various cell culture methods must be changed, for example, maintaining nutrient sources during the initial cell growth phase and enriching nutrient sources during the middle to late stages of culture. It is difficult to predict changes in protein concentration over a series of culture periods.

[0040] The embodiments described below enable accurate determination of protein concentration, prediction of changes in protein concentration depending on cell culture form, and prediction of changes in protein concentration over a series of culture periods.

[0041] [1. Configuration of Cell Culture System 10] FIG. 1 is a diagram showing the configuration of the cell culture system 10. The cell culture system 10 cultures (grows) cells isolated from biological tissue in a culture medium. The cells used in the cell culture system 10 may be mammalian cells or mammal-derived cells. The cells used in the cell culture system 10 may be adherent cells or suspension cells. Examples of adherent cells include HEK293 cells (human embryonic kidney cells), ES cells (embryonic stem cells), iPS cells (induced pluripotent stem cells), mesenchymal stem cells, fibroblasts, endothelial cells, and neural stem cells. Examples of suspension cells include Jurkat cells (human myeloid leukemia-derived cells), T cells, regulatory T cells, tumor-infiltrating lymphocytes, CAR-T cells, and CD34-positive cells. The cells used in the cell culture system 10 are not limited to those described above.

[0042] The cell culture system 10 includes a cell culture device 12 and a simulation device 14. The cell culture device 12 includes a cell culture circuit 16, a support device 18, and a control unit 20. A liquid flows through the cell culture circuit 16. The liquid includes at least one of a cell solution, a culture medium, a cleaning solution, and a detachment solution. The cell solution is a solution containing cells. The culture medium is a culture solution for growing cells. The culture medium is selected depending on the cells to be cultured. In this embodiment, two types of culture medium are used: a basal medium and a complete medium. For example, MEM (Minimum Essential Media) is used as the basal medium. For the complete medium, a basal medium containing protein (e.g., MEM) is used. Examples of proteins include albumin, growth factors, cytokines, etc. For example, bovine serum containing albumin, growth factors, etc. is added to the basal medium. The cleaning solution cleans the inside of the cell culture circuit 16. The washing liquid may be, for example, water, a buffer solution, or physiological saline. Examples of the buffer solution include PBS (Phosphate Buffered Saline) and TBS (Tris-Buffered Saline). The detachment liquid detaches cells from a bioreactor 30 (described later) of the cell culture circuit 16. Examples of the detachment liquid include trypsin or EDTA solution. The culture medium, washing liquid, and detachment liquid are not limited to the liquids described above.

[0043] [1-1 Cell Culture Device 12] [1-1-1 Cell Culture Circuit 16] The cell culture circuit 16 is discarded after a single use. In other words, the cell culture circuit 16 is discarded every time a predetermined number of cells are cultured. In other words, the cell culture circuit 16 is a disposable item. The cell culture circuit 16 includes a supply unit 22, a collection container 24, a waste liquid storage unit 26, and a culture body 28.

[0044] The supply unit 22 supplies liquids such as cell liquid, culture medium, cleaning liquid, and detachment liquid to the culture body 28. The supply unit 22 has a first supply unit 22a and a second supply unit 22b. The collection container 24 collects cells cultured in the culture body 28. The waste liquid storage unit 26 stores waste liquid generated in the culture body 28. Each of the collection container 24 and the waste liquid storage unit 26 is, for example, a medical bag made of a soft resin material in a bag shape. Each of the collection container 24 and the waste liquid storage unit 26 may be a tank made of a hard material, etc.

[0045] The culture body 28 has a bioreactor 30 , a flow path 32 , a gas exchange section 34 , a first sampling section 35 , a sensor section 36 , and a second sampling section 38 .

[0046] The bioreactor 30 has a plurality of hollow fiber membranes 40 and a cylindrical housing 42. The plurality of hollow fiber membranes 40 are housed within the housing 42. The hollow fiber membranes 40 are cylindrical. That is, the hollow fiber membranes 40 have a hole (inner hole) that penetrates from a first end to a second end. The first end of each hollow fiber membrane 40 is fixed to the first end of the housing 42. The second end of each hollow fiber membrane 40 is fixed to the second end of the housing 42. The hollow fiber membranes 40 are made of, for example, a polymer material.

[0047] The bioreactor 30 includes a first region 44 and a second region 46. The first region 44 is the inner pore of the plurality of hollow fiber membranes 40. The first region 44 is the region of the culture medium where cells exist. This region is also referred to as the culture region. The second region 46 is the space between the inner circumferential surface of the housing 42 and the outer circumferential surfaces of the plurality of hollow fiber membranes 40. The second region 46 is a non-culture region within the interior of the bioreactor 30. Each hollow fiber membrane 40 has a plurality of pores (not shown). The first region 44 and the second region 46 are connected to each other via the plurality of pores in each hollow fiber membrane 40. The diameter of each pore is large enough to prevent the passage of macromolecules (e.g., cells) while allowing the passage of small molecules (e.g., water, ions, oxygen, lactate, etc.). The diameter of each pore is set, for example, between 0.005 μm and 10 μm.

[0048] The housing 42 is fitted with a first inlet port 48, a first outlet port 50, a second inlet port 52, and a second outlet port 54. The first inlet port 48 is fitted to a first end of the housing 42. The first inlet port 48 is in communication with the first region 44 via inlets located at first ends of the plurality of hollow fiber membranes 40. The first outlet port 50 is fitted to a second end of the housing 42. The first outlet port 50 is in communication with the first region 44 via outlets located at second ends of the plurality of hollow fiber membranes 40.

[0049] The second inlet port 52 and the second outlet port 54 are attached to the outer peripheral surface of the housing 42. The second inlet port 52 is located between the center of the housing 42 and the first inlet port 48 in the longitudinal direction of the housing 42. The second outlet port 54 is located between the center of the housing 42 and the first outlet port 50 in the longitudinal direction of the housing 42. The second inlet port 52 and the second outlet port 54 each communicate with the second region 46.

[0050] The flow path 32 includes a plurality of tubes through which the liquid flows. Each tube is made of a soft resin material. The flow path 32 includes a first supply flow path 56, a first communication flow path 57, a second supply flow path 60, a second communication flow path 61, a recovery flow path 64, and a waste liquid flow path 66.

[0051] One end of the first supply flow path 56 is connected to the first supply unit 22a. The first supply unit 22a supplies the cell solution, complete medium, basal medium, washing solution, and detachment solution one by one at a predetermined timing to the first supply flow path 56. The other end of the first supply flow path 56 is connected to a first junction 68 of the first communication flow path 57.

[0052] The first junction 68 is located between the first end and the second end of the first communication flow path 57. The first end of the first communication flow path 57 is connected to the first inlet port 48. That is, the first communication flow path 57 is connected to the first region 44 in the inner hole of each hollow fiber membrane 40 via the first inlet port 48. The second end of the first communication flow path 57 is connected to the first outlet port 50. That is, the first communication flow path 57 is connected to the first region 44 in the inner hole of each hollow fiber membrane 40 via the first outlet port 50. The closed circuit formed by the first communication flow path 57 and the first region 44 is referred to as a first circulation flow path (inner circulation path) 58.

[0053] One end of the second supply flow path 60 is connected to the second supply unit 22 b. The second supply unit 22 b supplies one type of basal medium and one type of washing solution at a predetermined timing to the second supply flow path 60. The other end of the second supply flow path 60 is connected to a second junction 70 of the second communication flow path 61.

[0054] The second junction 70 is located between the first and second ends of the second communication flow path 61. The first end of the second communication flow path 61 is connected to the second inlet port 52. That is, the second communication flow path 61 communicates with the second region 46 outside the inner hole of each hollow fiber membrane 40 via the second inlet port 52. The second end of the second communication flow path 61 is connected to the second outlet port 54. That is, the second communication flow path 61 communicates with the second region 46 outside the inner hole of each hollow fiber membrane 40 via the second outlet port 54. The closed circuit formed by the second communication flow path 61 and the second region 46 is referred to as the second circulation flow path (outer circulation path) 62. Hereinafter, the first circulation flow path 58 and the second circulation flow path 62 may be collectively referred to as the "circulation flow path 72."

[0055] The recovery flow path 64 extends from the first circulation flow path 58. One end of the recovery flow path 64 is connected to a recovery branch portion 74 of the first circulation flow path 58. The recovery branch portion 74 is located between the first junction portion 68 and the first outlet port 50 in the first circulation flow path 58. The other end of the recovery flow path 64 is connected to the recovery container 24.

[0056] The waste liquid flow path 66 carries liquid to be discarded from the circulation flow path 72. The waste liquid flow path 66 includes a first waste liquid flow path 76, a second waste liquid flow path 78, and a third waste liquid flow path 80. The first waste liquid flow path 76 extends from the first circulation flow path 58. One end of the first waste liquid flow path 76 is connected to a first branch portion 82 of the first circulation flow path 58. The first branch portion 82 is located between the first outlet port 50 and the recovery branch portion 74 of the first circulation flow path 58. The second waste liquid flow path 78 extends from the second circulation flow path 62. One end of the second waste liquid flow path 78 is connected to a second branch portion 84 of the second circulation flow path 62. The second branch portion 84 is located between the second junction 70 and the second outlet port 54 of the second circulation flow path 62. The other end of the first waste liquid flow path 76 and the other end of the second waste liquid flow path 78 are connected to each other at an intermediate junction 86. One end of the third waste liquid flow path 80 is connected to the first waste liquid flow path 76 and the second waste liquid flow path 78 at the intermediate junction 86. The other end of the third waste liquid flow path 80 is connected to the waste liquid storage section 26.

[0057] The gas exchange unit 34 is attached to the second circulation flow path 62 between the second junction 70 and the second inlet port 52. The gas exchange unit 34 passes a gas of predetermined components through the liquid (basal medium) flowing through the second circulation flow path 62. The gas used in the gas exchange unit 34 has components similar to those of air in nature, for example. In other words, the gas contains nitrogen, oxygen, and carbon dioxide. Specifically, the gas contains, for example, 75% nitrogen, 20% oxygen, and 5% carbon dioxide by volume.

[0058] The first sampling unit 35 is connected to the first circulation flow path 58. The first sampling unit 35 extracts a portion of the liquid (complete medium) flowing through the first circulation flow path 58 and measures the components contained in the liquid. The first sampling unit 35 aseptically collects a tube fragment containing the internal liquid from a sufficiently long tube using, for example, a sterile joining device. The first sampling unit 35 has a protein sensor 92, a glucose sensor 94, and a lactate sensor 96.

[0059] The sensor unit 36 ​​is attached to the second circulation flow path 62 between the second outlet port 54 and the second branch portion 84. The sensor unit 36 ​​has a gas sensor 88 and a pH sensor 90. The gas sensor 88 measures the gas concentration of the liquid flowing through the second circulation flow path 62. Specifically, the gas sensor 88 includes an oxygen sensor and a carbon dioxide sensor. The oxygen sensor measures the oxygen concentration of the liquid flowing through the second circulation flow path 62. The carbon dioxide sensor measures the carbon dioxide concentration of the liquid flowing through the second circulation flow path 62. The pH sensor 90 measures the pH (hydrogen ion exponent) of the liquid flowing through the second circulation flow path 62. The gas sensor 88 and the pH sensor 90 each output the measurement results to the control unit 20.

[0060] The second sampling unit 38 is connected to a portion of the second circulation flow path 62 between the second outlet port 54 and the second branch 84. The second sampling unit 38 extracts a portion of the liquid flowing through the second circulation flow path 62 and measures the components contained in the liquid. Similar to the first sampling unit 35, the second sampling unit 38 has a protein sensor 92, a glucose sensor 94, and a lactate sensor 96.

[0061] The protein sensor 92 measures the protein concentration of the liquid extracted from the second circulation flow path 62. The glucose sensor 94 measures the glucose concentration of the liquid extracted from the second circulation flow path 62. The lactate sensor 96 measures the lactate concentration of the liquid extracted from the second circulation flow path 62. The protein sensor 92, the glucose sensor 94, and the lactate sensor 96 each output the measurement results to the control unit 20.

[0062] [1-1-2 Support Device 18] The above-described cell culture circuit 16 is set in the support device 18. The support device 18 has a cassette that supports the cell culture circuit 16. The support device 18 is a reusable item that can be used multiple times.

[0063] The support device 18 includes a plurality of pumps 98 and a plurality of clamps 100. Each of the plurality of pumps 98 applies a flow force to the liquid in the flow path 32 by squeezing the wall portion of the flow path 32. Each of the plurality of pumps 98 has a pressing member (not shown). The pressing member includes, for example, a rotating member and a plurality of pressing rollers. The plurality of pressing rollers are attached to the outer periphery of the rotating member. The plurality of pressing rollers are arranged at intervals in the circumferential direction of the rotating member. Each pressing roller rubs against the outer surface of the wall portion of the flow path 32.

[0064] The plurality of pumps 98 include a first supply pump 102, a first circulation pump 104, a second supply pump 106, and a second circulation pump 108. As shown in Figure 1, the state in which the cell culture circuit 16 is set on the support device 18 is simply referred to as the "set state."

[0065] In the set state, a part of the first supply flow path 56 is attached to the first supply pump 102. The first supply pump 102 applies a flow force to the liquid in the first supply flow path 56 in a direction from the supply unit 22 toward the first circulation flow path 58.

[0066] In the set state, a portion of the first circulation flow path 58 is attached to the first circulation pump 104. The first circulation pump 104 applies a flow force to the liquid in the first circulation flow path 58 in a direction from the first outlet port 50 to the first inlet port 48. Note that the first circulation pump 104 can also apply a flow force to the liquid in the first circulation flow path 58 in a direction from the first inlet port 48 to the first outlet port 50.

[0067] In the set state, a part of the second supply flow path 60 is attached to the second supply pump 106. The second supply pump 106 applies a flow force to the liquid in the second supply flow path 60 in a direction from the supply unit 22 toward the second circulation flow path 62.

[0068] In the set state, a portion of the second circulation flow path 62 is attached to the second circulation pump 108. The second circulation pump 108 applies a flow force to the liquid in the second circulation flow path 62 in a direction from the second outlet port 54 to the second inlet port 52. Note that the second circulation pump 108 can also apply a flow force to the liquid in the second circulation flow path 62 in a direction from the second inlet port 52 to the second outlet port 54.

[0069] The clamps 100 close the flow path 32 by pressing the outer surface of the flow path 32 toward the inner surface. For example, the clamps 100 are on-off valves. The clamps 100 include a recovery clamp 110, a first waste liquid clamp 112, a second waste liquid clamp 114, and a third waste liquid clamp 116.

[0070] In the set state, a portion of the recovery flow path 64 is attached to the recovery clamp 110. The recovery clamp 110 opens and closes the recovery flow path 64. In the set state, a portion of the first waste liquid flow path 76 is attached to the first waste liquid clamp 112. The first waste liquid clamp 112 opens and closes the first waste liquid flow path 76. In the set state, a portion of the second waste liquid flow path 78 is attached to the second waste liquid clamp 114. The second waste liquid clamp 114 opens and closes the second waste liquid flow path 78. In the set state, a portion of the third waste liquid flow path 80 is attached to the third waste liquid clamp 116. The third waste liquid clamp 116 opens and closes the third waste liquid flow path 80.

[0071] [1-1-3 Control Unit 20] Fig. 2 is a diagram showing the configuration of the control unit 20 of the cell culture device 12. The control unit 20 has a first calculation unit 118, a first storage unit 120, and various drive circuits (not shown).

[0072] The first calculation unit 118 has a processing circuit. The processing circuit may be a processor such as a CPU. The processing circuit may be an integrated circuit such as an ASIC or FPGA. The processor can perform various processes by executing programs stored in the first storage unit 120. The control unit 20 functions as a pump control unit 122, a clamp control unit 124, a gas exchange control unit 126, and a measurement unit 128. At least some of the processes may be performed by electronic circuits including discrete devices.

[0073] The pump control unit 122 controls each of the multiple pumps 98. Specifically, the pump control unit 122 outputs a command signal to a pump drive circuit (not shown). The pump drive circuit supplies each of the multiple pumps 98 with power in accordance with the command signal from the pump control unit 122. The clamp control unit 124 controls each of the multiple clamps 100. Specifically, the clamp control unit 124 outputs a command signal to a clamp drive circuit (not shown). The clamp drive circuit supplies each of the multiple clamps 100 with power in accordance with the command signal from the clamp control unit 124. The gas exchange control unit 126 controls the gas exchange unit 34. Specifically, the gas exchange control unit 126 outputs a command signal to a gas exchanger drive circuit (not shown). The gas exchanger drive circuit supplies the gas exchange unit 34 with power in accordance with the command signal from the gas exchange control unit 126. The measurement unit 128 acquires measurement results from each of the gas sensor 88, the pH sensor 90, the protein sensor 92, the glucose sensor 94, and the lactate sensor 96. The measurement unit 128 stores the acquired measurement results in the first storage unit 120 .

[0074] The first storage unit 120 has a volatile memory and a non-volatile memory. Examples of the volatile memory include RAM. The volatile memory is used as a working memory for the processor. The volatile memory temporarily stores data required for processing or calculation. Examples of the non-volatile memory include ROM and flash memory. The non-volatile memory is used as a storage memory. The non-volatile memory stores programs, tables, maps, etc. At least a portion of the first storage unit 120 may be provided in the processor, integrated circuit, etc. described above.

[0075] 3 is a diagram showing the configuration of the simulation device 14. The simulation device 14 has an input unit 130, a simulation unit 132, and a display unit 134. A personal computer, a smartphone, a tablet, or the like may be used as the simulation device 14.

[0076] The input unit 130 has a human-machine interface such as a keyboard, a mouse, a touchpad, etc. Alternatively, the input unit 130 may have a human-machine interface integrated with the display unit 134, such as a touch panel. The input unit 130 can input data corresponding to operations performed by the user to the simulation unit 132.

[0077] The simulation unit 132 includes a second calculation unit 136 and a second storage unit 138. The first calculation unit 118 and the first storage unit 120 may be used as the second calculation unit 136 and the second storage unit 138. In other words, the control unit 20 of the cell culture device 12 may be used as the simulation unit 132. The second calculation unit 136 includes a processing circuit. The processing circuit may be a processor such as a CPU. The processing circuit may be an integrated circuit such as an ASIC or FPGA. The processor can perform various processes by executing programs stored in the second storage unit 138. The simulation unit 132 functions as an acquisition unit 140, a simulation execution unit 142, and a display control unit 144. At least some of the processes may be performed by electronic circuits including discrete devices.

[0078] The acquisition unit 140 acquires data from outside the second calculation unit 136. For example, the acquisition unit 140 can acquire data from the input unit 130, the second storage unit 138, etc. The acquisition unit 140 can also acquire data specified by the input unit 130 from the second storage unit 138. The acquisition unit 140 can also acquire data specified by the input unit 130 from a device (such as the control unit 20) specified by the input unit 130. The simulation execution unit 142 uses the data acquired by the acquisition unit 140 to perform a simulation of cell growth and protein concentration changes using the cell culture device 12. The display control unit 144 displays various screens on the display unit 134. For example, the display control unit 144 can display data stored in the second storage unit 138 on the display unit 134. The display control unit 144 can display information corresponding to the results of the simulation executed by the simulation execution unit 142 on the display unit 134.

[0079] The second storage unit 138 has a volatile memory and a non-volatile memory. Examples of the volatile memory include RAM. The volatile memory is used as a working memory for the processor. The volatile memory temporarily stores data necessary for processing or calculation. Examples of the non-volatile memory include ROM and flash memory. The non-volatile memory is used as a storage memory. The non-volatile memory stores programs, tables, maps, etc. In this embodiment, the non-volatile memory stores the simulation program executed by the simulation execution unit 142. Furthermore, the non-volatile memory stores defaults for various data related to cell growth. At least a portion of the second storage unit 138 may be provided in the processor, integrated circuit, etc. described above.

[0080] FIG. 4 is a table showing parameter information 145. The second storage unit 138 stores the parameter information 145. The parameter information 145 is a data set of parameters used to perform calculations related to proteins in the culture simulation. The parameter information 145 includes various information corresponding to the type of protein (such as "protein degradation rate (also referred to as degradation rate, decomposition rate, etc.) at 37°C," "protein degradation rate (also referred to as degradation rate, decomposition rate, etc.) at 22°C," "protein adsorption rate," "protein inflow and outflow rates as viewed from inside the inner hole," and "protein inflow and outflow rates as viewed from outside the inner hole"). FIG. 4 shows parameter information 145 for bFGF, a growth factor. The second storage unit 138 also stores parameter information 145 corresponding to proteins other than bFGF.

[0081] The "protein deterioration rate at 37°C" refers to the protein deterioration rate caused by the ambient temperature of the first circulation flow path 58. This is a parameter that assumes that the first circulation flow path 58 is placed in a temperature environment of 37°C. If the first circulation flow path 58 is placed in a different temperature environment, a parameter corresponding to that temperature environment is set.

[0082] Similarly, the "protein deterioration rate at 22°C" refers to the protein deterioration rate caused by the ambient temperature of the first supply unit 22a. This parameter is based on the assumption that the first supply unit 22a is placed in a temperature environment of 22°C. If the first supply unit 22a is placed in a different temperature environment, a parameter corresponding to that temperature environment is set.

[0083] The display unit 134 has a human-machine interface such as a display. The display unit 134 may have a human-machine interface integrated with the input unit 130, such as a touch panel. The display unit 134 can display various screens described in [2] below.

[0084] [2 Screens] The display unit 134 can display an input screen 146 (Fig. 5), a growth data screen 148 (Fig. 6), a feedback condition screen 150 (Fig. 7), a result screen 152 (Figs. 8 and 9), and the like.

[0085] 5 is a diagram showing the input screen 146 displayed on the display unit 134. The input screen 146 is a screen for inputting various data used in the cell culture simulation. When the user operates the input unit 130, the display unit 134 displays the input screen 146.

[0086] The input screen 146 has a scale field 154. The scale field 154 is an input field for specifying the scale of cell culture in the simulation. The user can select a scale from a drop-down list displayed in the scale field 154.

[0087] The input screen 146 has a cell type field 156. The cell type field 156 is an input field for specifying proliferation data to be used in the simulation. Proliferation data is data indicating the proliferation state of cells under given culture conditions. The proliferation data specified in the cell type field 156 is a cell proliferation model for the simulation. The proliferation data is created based on data actually measured in a cell culture process performed in the past. The second memory unit 138 stores default proliferation data. In addition, the second memory unit 138 can store data actually measured in the cell culture process shown in step S5 of FIG. 10 as proliferation data. A specific example of proliferation data is shown in FIG. 6. The user can select either the default or actual measurement results from the drop-down list displayed in the cell type field 156.

[0088] The input screen 146 has a feedback field 160. The feedback field 160 is an input field for specifying whether or not feedback conditions are to be used in the simulation. Specific examples of feedback conditions are shown in FIG. 7. The user can select either "on" or "off" from the drop-down list displayed in the feedback field 160. When "on" is selected, the feedback conditions are used in the simulation. When "off" is selected, the feedback conditions are not used in the simulation.

[0089] The input screen 146 has a complete medium input field 162. The complete medium input field 162 is an input field for specifying data on the complete medium to be circulated through the first circulation flow path 58 in the simulation. The complete medium data includes the glucose concentration, the lactic acid concentration, the concentration of one or more proteins, the type of complete medium, pKa, the unit price of the complete medium, and the like. There may be one type of protein or multiple types of proteins. The user can specify the protein to be added to the complete medium in the complete medium input field 162. The complete medium data is condition data that indicates the culture conditions for the simulation.

[0090] The input screen 146 has a basal medium input field 164. The basal medium input field 164 is an input field for specifying data on the basal medium to be circulated through the second circulation flow path 62 in the simulation. The basal medium data includes the glucose concentration, the lactic acid concentration, the type of basal medium, pKa, the unit price of the basal medium, etc. The basal medium data is condition data that indicates the culture conditions for the simulation.

[0091] The input screen 146 has a gas input field 166. The gas input field 166 is an input field for specifying data on the gas used in the gas exchange unit 34 in the simulation. The gas data includes the volume ratio of oxygen contained in the gas, the volume ratio of carbon dioxide contained in the gas, the gas flow rate, etc. The gas data is condition data that indicates the culture conditions for the simulation.

[0092] The input screen 146 has an other input field 168. The other input field 168 is an input field for specifying other data related to the culture medium. The other data includes the capacity of the first circulation flow path 58, the capacity of the second circulation flow path 62, atmospheric pressure, water vapor pressure, etc. The other data is condition data that indicates the culture conditions of the simulation.

[0093] The input screen 146 has a pump speed input field 170. The pump speed input field 170 is an input field for specifying the flow rate of each pump 98 in the simulation. The flow rate of each pump 98 is set for each day of the culture period. The flow rate of each pump 98 is condition data that indicates the culture conditions of the simulation.

[0094] The input screen 146 has a number of days input field 172. The number of days input field 172 is an input field for specifying the number of days for cell culture in the simulation. The number of days for culture is condition data that indicates the culture conditions for the simulation.

[0095] The input screen 146 has a seeding number input field 174. The seeding number input field 174 is an input field for specifying the seeding number in the simulation. The seeding number is condition data indicating the culture conditions of the simulation.

[0096] The input screen 146 has a doubling time input field 176. The doubling time input field 176 is an input field for specifying the time it takes for cells to double (doubling time) in the simulation. The doubling time is condition data that indicates the culture conditions for the simulation.

[0097] The input screen 146 has a temperature input field 178. The temperature input field 178 is an input field for specifying the environmental temperature in the simulation. The environmental temperature is condition data indicating the culture conditions of the simulation.

[0098] The input screen 146 has a threshold input field 180. The threshold input field 180 is an input field for specifying thresholds for the glucose concentration, the lactate concentration, the partial pressure of oxygen, the partial pressure of carbon dioxide, pH, and protein. At least one of a lower limit (LLR), a lower warning value (LAR), an upper limit (ULR), and an upper warning value (UAR) is specified as the threshold. For example, only the lower limit (LLR) and the lower warning value (LAR) may be specified. For example, only the upper limit (ULR) and the upper warning value (UAR) may be specified. For example, the lower limit (LLR), the lower warning value (LAR), the upper limit (ULR), and the upper warning value (UAR) may be specified. The user can specify any threshold.

[0099] 6 is a diagram showing the growth data screen 148 displayed on the display unit 134. The growth data screen 148 is a screen showing each growth data. When the user operates the input unit 130, the display unit 134 displays the growth data screen 148. The second storage unit 138 stores each growth data as a data set.

[0100] The proliferation data screen 148 has a biodata graph 184. In the biodata graph 184, the horizontal axis represents time, and the vertical axis represents the metabolic rate of the biodata. The biodata graph 184 displays a metabolic rate line 186 and a metabolic rate line 188. The metabolic rate line 186 shows the change in the metabolic rate of glucose. The metabolic rate line 188 shows the change in the metabolic rate of lactate. The metabolic rate of the biodata is proliferation data that indicates the proliferation state of the cells.

[0101] The proliferation data screen 148 has a gas data graph 190. In the gas data graph 190, the horizontal axis represents time, and the vertical axis represents the metabolic rate of biodata. The gas data graph 190 displays a metabolic rate line 192 and a metabolic rate line 194. The metabolic rate line 192 shows the progress of the metabolic rate of oxygen. The metabolic rate line 194 shows the progress of the metabolic rate of carbon dioxide. The metabolic rate of the gas data is proliferation data that indicates the proliferation state of the cells.

[0102] The proliferation data screen 148 has a cell graph 196. In the cell graph 196, the horizontal axis represents time and the vertical axis represents the number of cells. A cell number line 198 is displayed on the cell graph 196. The cell number line 198 shows the progress of the number of cells. The cell number is proliferation data that indicates the proliferation state of the cells.

[0103] 7 is a diagram showing the feedback condition screen 150 displayed on the display unit 134. The feedback condition screen 150 is a screen for inputting feedback conditions and change data. The feedback conditions are conditions for changing the condition data during the simulation depending on the situation of the simulation. The change data is the change value of the condition data. When the user operates the input unit 130, the display unit 134 displays the feedback condition screen 150.

[0104] The feedback condition screen 150 has a condition field 200 and a data field 202. The condition field 200 is an input field for specifying feedback conditions. The data field 202 is an input field for specifying change data. For example, the condition field 200 and data field 202 indicated by No. 1 in FIG. 7 mean that "when lactic acid exceeds XXX [mM], the flow rate of the first circulation pump 104 is set to XXX [mL / min]." The feedback conditions and change data are condition data that indicate the culture conditions of the simulation. Although not shown, feedback conditions such as glucose, carbon dioxide, pH, and various proteins can also be specified.

[0105] When the save button 182 on the input screen 146 shown in FIG. 5 is pressed, the second storage unit 138 stores the data designated in each input field on the feedback condition screen 150 .

[0106] 8 and 9 are diagrams showing the result screen 152 displayed on the display unit 134. FIG. 8 shows the upper part of the result screen 152, and FIG. 9 shows the lower part of the result screen 152. When the user scrolls downward while the result screen 152 of FIG. 8 is displayed on the display unit 134, the result screen 152 of FIG. 9 is displayed on the display unit 134. The result screen 152 is a screen that shows the results of the simulation performed in step S2 of FIG. 10. After the simulation, the user operates the input unit 130, which causes the display control unit 144 to display the result screen 152 on the display unit 134.

[0107] The result screen 152 has a waste amount column 204 and a cost column 206. The waste amount column 204 displays the total amount of culture medium discarded in the simulated cell culture. The cost column 206 displays the cost of the simulated cell culture.

[0108] The result screen 152 has a glucose graph 208 ( FIG. 8 ). In the glucose graph 208, the horizontal axis represents time, and the vertical axis represents glucose concentration. The glucose graph 208 displays a concentration line 210, a warning line 212, and a lower limit line 214. The concentration line 210 shows the progression of glucose concentration during the incubation period. The warning line 212 indicates the boundary between the OK range and the warning range. The lower limit line 214 indicates the boundary between the warning range and the NG range. The boundary value indicated by the warning line 212 is the lower warning value of the glucose concentration entered in the threshold input field 180 of the input screen 146. The boundary value indicated by the lower limit line 214 is the lower limit of the glucose concentration entered in the threshold input field 180 of the input screen 146. The range above the warning line 212 is the OK range. The range below the lower limit line 214 is the NG range. The range between the warning line 212 and the lower limit line 214 is the warning range. It is preferable that the concentration line 210 is in the OK range above the warning line 212. That is, it is preferable that the glucose concentration is within the OK range at all times during the culture period.

[0109] The results screen 152 includes a lactate graph 216 ( FIG. 8 ). In the lactate graph 216, the horizontal axis represents time, and the vertical axis represents lactate concentration. The lactate graph 216 displays a concentration line 218, a warning line 220, and an upper limit line 222. The concentration line 218 indicates the progression of lactate concentration during the culture period. The warning line 220 indicates the boundary between the OK range and the warning range. The upper limit line 222 indicates the boundary between the warning range and the NG range. The boundary value indicated by the warning line 220 is the upper warning value for the lactate concentration entered in the threshold input field 180 of the input screen 146. The boundary value indicated by the upper limit line 222 is the upper limit for the lactate concentration entered in the threshold input field 180 of the input screen 146. The range below the warning line 220 is the OK range. The range above the upper limit line 222 is the NG range. The range between the warning line 220 and the upper limit line 222 is the warning range. The concentration line 218 is preferably in the OK range below the warning line 220. That is, the lactate concentration is preferably within the OK range at all times during the culture period.

[0110] The result screen 152 has an O2 graph 224 ( FIG. 8 ). In the O2 graph 224, the horizontal axis represents time, and the vertical axis represents oxygen partial pressure. The O2 graph 224 displays a partial pressure line 226, a warning line 228, and a lower limit line 230. The partial pressure line 226 shows the change in oxygen partial pressure during the culture period. The warning line 228 indicates the boundary between the OK range and the warning range. The lower limit line 230 indicates the boundary between the warning range and the NG range. The boundary value indicated by the warning line 228 is the lower warning value for the oxygen partial pressure entered in the threshold input field 180 of the input screen 146. The boundary value indicated by the lower limit line 230 is the lower limit for the oxygen partial pressure entered in the threshold input field 180 of the input screen 146. The range above the warning line 228 is the OK range. The range below the lower limit line 230 is the NG range. The range between the warning line 228 and the lower limit line 230 is the warning range. The partial pressure line 226 is preferably in the OK range above the warning line 228. That is, the partial pressure of oxygen is preferably within the OK range at all times during the culture period.

[0111] The result screen 152 has a CO2 graph 232 ( FIG. 8 ). In the CO2 graph 232, the horizontal axis represents time, and the vertical axis represents the partial pressure of carbon dioxide. The CO2 graph 232 displays a partial pressure line 234, a warning line 236, and an upper limit line 238. The partial pressure line 234 shows the change in the partial pressure of carbon dioxide during the culture period. The warning line 236 indicates the boundary value between the OK range and the warning range. The upper limit line 238 indicates the boundary value between the warning range and the NG range. The boundary value indicated by the warning line 236 is the upper warning value for the partial pressure of carbon dioxide entered in the threshold input field 180 of the input screen 146. The boundary value indicated by the upper limit line 238 is the upper limit value for the partial pressure of carbon dioxide entered in the threshold input field 180 of the input screen 146. The range below the warning line 236 is the OK range. The range above the upper limit line 238 is the NG range. The range between the warning line 236 and the upper limit line 238 is the warning range. The partial pressure line 234 is preferably in the OK range below the warning line 236. That is, the partial pressure of carbon dioxide is preferably within the OK range at all times during the culture period.

[0112] The result screen 152 has a pH graph 240 ( FIG. 8 ). In the pH graph 240, the horizontal axis represents time, and the vertical axis represents the pH of the culture medium. The pH graph 240 displays a pH line 242, a lower warning line 244, a lower limit line 246, an upper warning line 248, and an upper limit line 250. The pH line 242 shows the progression of pH during the culture period. The lower warning line 244 indicates the boundary between the OK range and the lower warning range. The lower limit line 246 indicates the boundary between the lower warning range and the first NG range. The upper warning line 248 indicates the boundary between the OK range and the upper warning range. The upper limit line 250 indicates the boundary between the upper warning range and the second NG range. The boundary value indicated by the lower warning line 244 is the lower warning value of pH entered in the threshold input field 180 of the input screen 146. The boundary value indicated by the lower limit line 246 is the lower limit value of pH entered in the threshold input field 180 of the input screen 146. The boundary value indicated by the upper warning line 248 is the upper warning value of pH entered in the threshold input field 180 of the input screen 146. The boundary value indicated by the upper warning line 250 is the upper limit value of pH entered in the threshold input field 180 of the input screen 146. The range between the lower warning line 244 and the upper warning line 248 is the OK range. The range below the lower limit line 246 is the first NG range. The range between the lower warning line 244 and the lower limit line 246 is the lower warning range. The range above the upper limit line 250 is the second NG range. The range between the upper warning line 248 and the upper limit line 250 is the upper warning range. It is preferable that the pH line 242 be in the OK range between the lower warning line 244 and the upper warning line 248. That is, it is preferable that the pH of the medium is within the OK range throughout the entire culture period.

[0113] The result screen 152 has a flow rate graph 252 ( FIG. 8 ). In the flow rate graph 252, the horizontal axis represents time, and the vertical axis represents the flow rate of the first circulation pump 104 and the flow rate of the second circulation pump 108. The flow rate graph 252 displays a first flow rate line 254 and a second flow rate line 256. The first flow rate line 254 indicates the change in the flow rate of the first circulation pump 104 during the culture period. The second flow rate line 256 indicates the change in the flow rate of the second circulation pump 108 during the culture period.

[0114] The result screen 152 includes an albumin graph 258 ( FIG. 9 ). In the albumin graph 258, the horizontal axis represents time, and the vertical axis represents concentration. Note that the left vertical axis (IC) represents the concentration in the first circulation flow path 58, and the right vertical axis (EC) represents the albumin concentration in the second circulation flow path 62. This is the same for the other graphs in FIG. 9 . Concentration lines 260 a and 260 b are displayed on the albumin graph 258. The concentration line 260 a represents the change in albumin concentration in the first circulation flow path 58 during the culture period. The concentration line 260 b represents the change in albumin concentration in the second circulation flow path 62 during the culture period. Although not shown, the albumin graph 258 may also display a lower warning line, a lower limit line, an upper warning line, an upper limit line, and the like, similar to the graphs in FIG. 8 . This is the same for the other graphs in FIG. 9 .

[0115] The result screen 152 has a bFGF graph 262 ( FIG. 9 ). Concentration lines 264 a and 264 b are displayed on the bFGF graph 262. The concentration line 264 a indicates the change in the bFGF concentration in the first circulation flow path 58 during the culture period. The concentration line 264 b indicates the change in the bFGF concentration in the second circulation flow path 62 during the culture period.

[0116] The results screen 152 includes an IGF graph 266 ( FIG. 9 ). Concentration lines 268 a and 268 b are displayed on the IGF graph 266. The concentration line 268 a indicates the change in IGF concentration in the first circulation flow path 58 during the culture period. The concentration line 268 b indicates the change in IGF concentration in the second circulation flow path 62 during the culture period.

[0117] The result screen 152 has an IL-2 graph 270 ( FIG. 9 ). The IL-2 graph 270 displays concentration lines 272 a and 272 b. The concentration line 272 a shows the change in the IL-2 concentration in the first circulation flow path 58 during the culture period. The concentration line 272 b shows the change in the IL-2 concentration in the second circulation flow path 62 during the culture period.

[0118] The result screen 152 can also show the transition of the concentration of other proteins. In other words, the result screen 152 can show the transition of the concentration of the protein specified in the complete medium input field 162 of the input screen 146.

[0119] [3 Cell Culture Method] [3-1 Overall Flow of Cell Culture Method] Figure 10 is a flowchart showing the flow of the cell culture method performed using the cell culture system 10. Steps S1 to S3 in Figure 10 are performed by the simulation device 14. Step S5 in Figure 10 is performed by the cell culture device 12. Details of step S5 are shown in Figure 16. Steps S4 and S6 are determined by the user.

[0120] Before step S1, the user operates the input unit 130 to start the simulation program. In response to the user's operation, the second calculation unit 136 executes the simulation program stored in the second storage unit 138. Then, the display control unit 144 displays the input screen 146 shown in FIG. 5 on the display unit 134.

[0121] In step S1, the user operates the input unit 130 to input data into each input field on the input screen 146. For example, in the first simulation, the user specifies the default in the cell type field 156. After specifying each piece of data, the user presses the save button 182. The input unit 130 inputs the data in each input field into the simulation unit 132. The second storage unit 138 stores each piece of data. When step S1 is completed, the process proceeds to step S2.

[0122] In step S2, the user operates the input unit 130 to start a cell culture simulation. In response to an instruction from the input unit 130, the simulation execution unit 142 starts a cell culture simulation using each data (growth data, condition data, and various protein parameters) stored in the second storage unit 138. The simulation execution unit 142 simulates cell culture for a specified culture period using the growth data, condition data, and various protein parameters. The simulation execution unit 142 calculates the amount of each component in the culture medium at each time during the culture period. Specifically, the simulation execution unit 142 calculates the glucose concentration at each time during the culture period. The simulation execution unit 142 also calculates the lactic acid concentration at each time during the culture period. The simulation execution unit 142 also calculates the oxygen partial pressure at each time during the culture period. The simulation execution unit 142 also calculates the carbon dioxide partial pressure at each time during the culture period. The simulation execution unit 142 also calculates the medium pH at each time during the culture period. The simulation execution unit 142 can calculate the amount of each component using a known calculation method. The calculation method is shown, for example, in the document "Journal of Chemical Technology and Metallurgy, 48, 4, 2013, 351-356 EXPERIMENTAL DETERMINATION OF THE VOLUMETRIC MASS TRANSFER COEFFICIENT." The simulation execution unit 142 also calculates the protein concentration at each time during the culture period. The method of calculating the protein concentration performed by the simulation execution unit 142 will be described in [3-2] below. The second storage unit 138 stores the calculation results of the simulation execution unit 142.

[0123] The simulation execution unit 142 determines whether the feedback condition is satisfied based on each calculated value at each time. If the feedback condition is satisfied, the simulation execution unit 142 changes some of the culture conditions in accordance with the setting of the feedback condition. For example, the simulation execution unit 142 changes the flow rate data of one of the pumps 98. The simulation execution unit 142 continues the simulation using the changed data. The second storage unit 138 stores the changed condition data.

[0124] When the cell culture simulation is completed, the simulation execution unit 142 calculates the total consumption amount and total waste amount of culture medium in the simulation. The simulation execution unit 142 also calculates costs using the total consumption amount of culture medium and the unit price of the culture medium. The second storage unit 138 stores the calculation results of the simulation execution unit 142. When step S2 is completed, the process proceeds to step S3.

[0125] In step S3, the user operates the input unit 130 to display the results of the simulation. In response to an instruction from the input unit 130, the display control unit 144 displays the results of the simulation on the display unit 134. The display unit 134 displays a result screen 152 shown in Figures 8 and 9. When step S3 ends, the process proceeds to step S4.

[0126] In step S4, the user determines whether or not another simulation is necessary. If there is a portion of the progress of the calculated values ​​in any of the graphs on the result screen 152 that falls outside the OK range, it is preferable for the user to change the condition data and run the simulation again. If another simulation is necessary (step S4: YES), the process returns to step S1. On the other hand, if another simulation is not necessary (step S4: NO), the process proceeds to step S5.

[0127] In step S5, the user cultures cells using the cell culture device 12. The user operates the input device (not shown) of the cell culture device 12 to set the culture conditions specified in step S1 of FIG. 10. For example, if the control unit 20 of the cell culture device 12 and the simulation unit 132 of the simulation device 14 are connected by a signal line, the control unit 20 acquires condition data of the culture conditions from the second storage unit 138 of the simulation unit 132. The cell culture process will be described in [3-3] below. After the cell culture process is completed, the simulation unit 132 acquires condition data of the culture conditions and growth data of new cells from the control unit 20. The second storage unit 138 stores the data acquired from the control unit 20. When step S5 is completed, the process proceeds to step S6.

[0128] In step S6, the user determines whether another simulation is necessary. Cell culture is performed multiple times. The user gradually increases the scale of the cell culture as the number of cell cultures increases. It is preferable that the user perform a simulation each time the scale of the cell culture is increased. If another simulation is necessary (step S6: YES), the process returns to step S1. On the other hand, if another simulation is not necessary (step S6: NO), the cell culture ends.

[0129] In step S6, the user may compare the results of the simulation performed in step S3 with the measurement results of the cell culture performed in step S5. In this case, the display control unit 144 may display on the display unit 134 the predicted values ​​of proteins, etc. obtained by the simulation and the actual measured values ​​of proteins, etc. obtained by actual cell culture. Furthermore, the display control unit 144 may display on the display unit 134 a range of ±5% × day of the actual measured value as the allowable range of proteins, etc. In this case, the display control unit 144 calculates a value of −5% × day of the actual measured value as the lower limit of the allowable range. Furthermore, the display control unit 144 calculates a value of +5% × day of the actual measured value as the upper limit of the allowable range.

[0130] [3-2 Method for Calculating Protein Concentration] The simulation execution unit 142 calculates the transition of the protein concentration during a specified culture period. The simulation execution unit 142 calculates the concentration at predetermined time intervals as the transition of the protein concentration. For example, the simulation execution unit 142 calculates the concentration at one-minute intervals. Note that the interval at which the protein concentration is calculated is not limited to this. For example, the interval at which the protein concentration is calculated may be one second or one day.

[0131] The simulation execution unit 142 calculates the transition of protein concentration using a calculation method corresponding to the culture form for which the simulation is being performed. For example, the simulation execution unit 142 can execute simulations of the following eight culture forms (first culture form to eighth culture form). The first, third, fifth, and seventh culture forms are executed in a culture process for suspension cells. The second, fourth, sixth, and eighth culture forms are executed in a culture process for adherent cells. In each of the culture processes for suspension cells and adherent cells, one of the above-described culture forms may be executed, or a combination of multiple culture forms may be executed.

[0132] For example, the first and second culture forms are mainly performed from the early to middle stages of the cell culture process. The third and fourth culture forms are mainly performed from the middle to late stages of the cell culture process. The fifth culture form is performed as appropriate during the culture period to collect cells. Each culture form differs in the medium supplied, the method of supplying the medium, the method of disposing of the medium, etc. When performing a simulation of culture for an arbitrary period, the simulation execution unit 142 can perform a simulation that combines multiple culture forms.

[0133] The simulation execution unit 142 can obtain a simulation result for the entire culture period by connecting data calculated for the protein concentration during each culture period for each culture type using a calculation formula (see below) for the protein concentration in the first circulation channel 58 and a calculation formula (see below) for the protein concentration in the second circulation channel 62, respectively. For example, the simulation execution unit 142 can obtain a simulation result for the entire culture period by calculating data indicating the concentration for each culture period using the calculation formulas for the protein concentration in the first, third, and fifth culture types used in the culture of suspension cells, and connecting the calculated data. For example, the simulation execution unit 142 can obtain a simulation result for the entire culture period by calculating data indicating the concentration for each culture period using the calculation formulas for the protein concentration in the second and fourth culture types used in the culture of adherent cells, and connecting the calculated data.

[0134] [3-2-1 Calculation Method in First Culture Mode] Figure 11 is a diagram illustrating the operation of the cell culture device 12 during cell culture in the first culture mode. Figure 12 is a diagram illustrating the operation of the cell culture device 12 during cell collection in the first culture mode. In the first culture mode, the controller 20 controls the first supply unit 22a, the second supply unit 22b, the pumps 98, and the clamps 100 to adjust the flow path through which the culture medium flows and the flow rate of the culture medium. Similarly, the controller 20 adjusts the flow path through which the culture medium flows and the flow rate of the culture medium for the second to eighth culture modes described below. The first culture mode is as follows: (a) Complete medium is supplied from the first supply unit 22a to the first circulation flow path 58. (b) Basal medium is not supplied from the second supply unit 22b to the second circulation flow path 62. (c) A portion of the culture medium is discarded from the second circulation flow path 62 to the waste liquid storage unit 26 via the second waste liquid flow path 78.

[0135] The simulation execution unit 142 calculates the protein concentration (Pro_IC[n+1]) in the first circulation flow path 58 using the following equations (1) to (5). The simulation execution unit 142 also calculates the protein concentration (Pro_EC[n+1]) in the second circulation flow path 62 using the following equations (6) to (9).

[0136]

[0137] The variables included in the above formulas (1) to (9) are defined as follows. Variables marked with [n] are variables obtained in the nth calculation among calculations performed at one-minute intervals. n is a value ranging from zero to (length of culture period / calculation time interval). Pro_IC: protein concentration in the first circulation flow path 58 [unit: ng / mL]. Pro_EC: protein concentration in the second circulation flow path 62 [unit: ng / mL]. t: elapsed time in the simulation [unit: min]. Cm: protein concentration in the complete medium supplied from the first supply unit 22a to the first circulation flow path 58 [unit: ng / mL]. A_r: rate of protein loss from the medium in the first supply flow path 56 and the first circulation flow path 58 due to protein adsorption and deposition on the inner surface of the hollow fiber membrane 40 [unit: %]. Deg_22: Degradation rate (disappearance rate) of protein in the first supply section 22a due to the ambient temperature (22°C) [% / day]. Deg_37: Degradation rate (disappearance rate) of protein in the first circulation flow path 58 due to the ambient temperature (37°C) [% / day]. IC_ir: Flow rate of the first supply pump 102 [unit: mL / min]. V_IC: Volume of the first circulation flow path 58 [unit: mL]. V_EC: Volume of the second circulation flow path 62 [unit: mL]. Mx_pro: Consumption rate of protein consumed by cells per unit time [unit: mg / min]. k_EtoI: Rate (coefficient) of inflow and outflow of protein in the culture medium between the inside and outside of the inner hole through the hollow fiber membrane 40, as viewed from the inside of the inner hole [unit: 1 / min]. k_ItoE: the rate (coefficient) of inflow and outflow of proteins in the culture medium between the inside and outside of the inner hole through the hollow fiber membrane 40, as viewed from the outside of the inner hole [unit: 1 / min].

[0138] In other words, the adsorption rate (correction rate) is the proportion of proteins that cannot be consumed by cells due to adsorption, aggregation, and deposition of proteins in at least one of the first circulation flow path (inner circulation path) 58 and the second circulation flow path (outer circulation path) 62.

[0139] The terms included in the above equation (1) are defined as follows: Pro_IC[n+1] - Pro_IC[n] / t[n+1] - t[n]: the rate of change in protein concentration in the first circulation channel 58 between the timing of the nth calculation and the timing of the n+1th calculation. F_i_b: the rate at which the protein concentration changes in the first circulation channel 58 due to the supply of culture medium to the first circulation channel 58 (supply rate). L_b_c: the rate at which the protein concentration changes in the first circulation channel 58 due to the consumption of protein by the cells (consumption rate). E_t_m1: the rate at which the protein concentration changes in the first circulation channel 58 due to the inflow and outflow of culture medium between the inside and outside of the inner hole via the hollow fiber membrane 40 (exchange rate). The concentrations here are calculated using the volume of the first circulation channel 58 as the denominator. L_i_b1: the rate at which the protein concentration changes in the first circulation channel 58 due to the degradation of the protein in the first circulation channel 58 (degradation rate).

[0140] The terms included in the above formula (6) are defined as follows: Pro_EC[n+1] - Pro_EC[n] / t[n+1] - t[n]: the rate of change in protein concentration in the second circulation flow path 62 between the timing of the nth calculation and the timing of the n+1th calculation. L_t_w2: the rate at which the protein concentration changes in the second circulation flow path 62 due to the disposal of a portion of the culture medium through the second circulation flow path 62 (disposal rate). E_t_m2: the rate at which the protein concentration changes in the second circulation flow path 62 due to the inflow and outflow of culture medium between the inside and outside of the inner hole via the hollow fiber membrane 40 (exchange rate). The concentrations here are expressed using the volume of the second circulation flow path 62 as the denominator. L_i_b2: the rate at which the protein concentration changes in the second circulation flow path 62 due to the degradation of the protein in the second circulation flow path 62 (degradation rate).

[0141] The acquisition unit 140 acquires Cm in the above formula (2), IC_ir in the above formula (2) and formula (7), V_IC in the above formula (2) and formula (3), and V_EC in the above formula (7) from information input to the input screen 146. The acquisition unit 140 also acquires A_r in the above formula (2), Deg_22 in the above formula (2), k_EtoI in the above formula (4), Deg_37 in the above formula (5) and formula (9), and k_ItoE in the above formula (8) from parameter information 145 stored in the second storage unit 138. The acquisition unit 140 also acquires Pro_IC[n] and Pro_EC[n] from the results of the previous calculation. Pro_IC[0] and Pro_EC[0] are initial values ​​of protein concentration. The results of each calculation are stored in the second storage unit 138. The acquiring unit 140 also acquires Mx_pro[n] from the second storage unit 138. Note that Mx_pro[n] may be zero.

[0142] The simulation execution unit 142 substitutes each parameter acquired by the acquisition unit 140 into the above equations (1) to (9) to calculate Pro_IC[n+1] and Pro_EC[n+1] as the n+1th calculation result.

[0143] The first culture mode is primarily used in cell culture processes, but may also be used in cell collection processes. When the first culture mode is used in a cell collection process, as shown in FIG. 12 , for example, a basal medium is supplied from the first confluence 68 to both the first inlet port 48 and the first outlet port 50. This allows cells present in the first circulation channel 58 to be collected within the hollow fiber membrane 40. The formula for calculating the protein concentration in the first culture mode is the same for both the cell culture process and the cell collection process.

[0144] 13 is a diagram showing the operation of the cell culture device 12 during cell culture in the second culture mode. The second culture mode is as follows: (a) Complete medium is supplied from the first supply unit 22a to the first circulation flow path 58. (b) No basal medium is supplied from the second supply unit 22b to the second circulation flow path 62. (c) A portion of the medium is discarded from the first circulation flow path 58 to the waste liquid storage unit 26 via the first waste liquid flow path 76.

[0145] In the second culture form, the above formulas (2) to (5), (8), and (9) are used. In addition, in the second culture form, the following formulas (10) and (11) are used instead of the above formula (1). In addition, in the second culture form, the following formula (12) is used instead of the above formula (6).

[0146]

[0147] The left term of the above equation (11) is defined as follows: L_t_w1: the rate at which the protein concentration changes in the first circulation channel 58 due to the discarding of a portion of the culture medium through the first circulation channel 58 (discard rate).

[0148] 14 is a diagram showing the operation of the cell culture device 12 during cell culture in the third culture mode. The third culture mode is as follows: (a) Complete medium is supplied from the first supply unit 22a to the first circulation flow path 58. (b) Basal medium is supplied from the second supply unit 22b to the second circulation flow path 62. (c) A portion of the medium is discarded from the second circulation flow path 62 to the waste liquid storage unit 26 via the second waste liquid flow path 78.

[0149] In the third culture mode, the above formulas (1) to (6), (8) and (9) are used. In addition, in the third culture mode, the following formula (13) is used instead of the above formula (7).

[0150]

[0151] EC_ir included in the above formula (13) is defined as follows: EC_ir: flow rate of the second supply pump 106 [unit: mL / min].

[0152] 15 is a diagram showing the operation of the cell culture device 12 during cell culture in the fourth culture mode. The fourth culture mode is as follows: (a) Complete medium is supplied from the first supply unit 22a to the first circulation flow path 58. (b) Basal medium is supplied from the second supply unit 22b to the second circulation flow path 62. (c) A portion of the medium is discarded from the first circulation flow path 58 to the waste liquid storage unit 26 via the first waste liquid flow path 76.

[0153] In the fourth culture form, the above formulas (2) to (5), (8), and (9) are used. In addition, in the fourth culture form, the above formula (10) and the following formula (14) are used instead of the above formula (1). In addition, in the fourth culture form, the above formula (12) is used instead of the above formula (6).

[0154]

[0155] [3-2-5 Calculation Method in Fifth Culture Form] The fifth culture form is as follows. The operation of the cell culture device 12 during cell culture in the fifth culture form is the same as the operation of the cell culture device 12 during cell culture in the first culture form ( FIGS. 11 and 12 ), except for the following (a): (a) The basal medium is supplied from the first supply unit 22 a to the first circulation flow path 58. (b) The basal medium is not supplied from the second supply unit 22 b to the second circulation flow path 62. (c) A portion of the medium is discarded from the second circulation flow path 62 to the waste liquid storage unit 26 via the second waste liquid flow path 78.

[0156] In the fifth culture form, the above formulas (1) to (9) are used, as in the first culture form. However, in the fifth culture form, a basal medium is used instead of a complete medium, so no protein is supplied from the first supply unit 22a to the first circulation flow path 58. Therefore, Cm in the above formula (2) is essentially zero. In other words, the above formula (2) becomes the following formula (2)'.

[0157]

[0158] The main reason for supplying basal medium to the first circulation flow path 58 is to remove waste products such as lactic acid. As cells grow, waste products such as lactic acid accumulate in the first region 44, which is the inner pore of the hollow fiber membrane 40. For example, as in the second culture form, it is possible to flush the waste products from the inside to the outside of the first region 44 by supplying complete medium to the first circulation flow path 58. However, when complete medium is used to remove the waste products, proteins are discarded along with the waste products. Therefore, the discarded proteins are wasted. By using basal medium instead of complete medium, it is possible to remove waste products from the first region 44 while preventing the use of more protein than necessary.

[0159] In the fifth culture form, waste products accumulated in the first region 44 pass through the pores of the hollow fiber membrane 40 and are pushed out into the second region 46. The waste products in the second region 46 are discarded together with the culture medium into the waste liquid storage section 26 via the second circulation channel 62. According to the fifth culture form, the waste products accumulated in the first region 44 can be discarded into the waste liquid storage section 26 without significantly changing the protein concentration in the first circulation channel 58.

[0160] In the fifth culture form, similar to the first culture form, the basal medium may be supplied from the first confluence 68 to both the first inlet port 48 and the first outlet port 50. This allows the cells present in the first circulation flow path 58 to be collected in the hollow fiber membrane 40. The process in the fifth culture form is referred to as the cell collection process.

[0161] [3-2-6 Calculation Method in the Sixth Culture Configuration] The sixth culture configuration is as follows. The operation of the cell culture device 12 during cell culture in the sixth culture configuration is the same as the operation of the cell culture device 12 during cell culture in the second culture configuration ( FIG. 13 ), except for the following (a): (a) The basal medium is supplied from the first supply unit 22 a to the first circulation flow path 58. (b) The basal medium is not supplied from the second supply unit 22 b to the second circulation flow path 62. (c) A portion of the medium is discarded from the first circulation flow path 58 to the waste liquid storage unit 26 via the first waste liquid flow path 76.

[0162] In the sixth culture form, as in the second culture form, the formulas (2) to (5), (8), and (9) to (12) are used. However, in the sixth culture form, as in the fifth culture form, a basal medium is used instead of a complete medium. In other words, the formula (2) becomes the formula (2)'.

[0163] In the sixth culture form, the waste products and proteins accumulated in the first region 44 are discarded together with the culture medium into the waste liquid storage section 26 via the first circulation channel 58. According to the sixth culture form, the concentration of excess proteins in the first circulation channel 58 can be reduced, and the waste products accumulated in the first region 44 can be discarded into the waste liquid storage section 26.

[0164] [3-2-7 Calculation Method in Seventh Culture Form] The seventh culture form is as follows. The operation of the cell culture device 12 during cell culture in the seventh culture form is the same as the operation of the cell culture device 12 during cell culture in the third culture form ( FIG. 14 ), except for the following (a): (a) The basal medium is supplied from the first supply unit 22 a to the first circulation flow path 58. (b) The basal medium is supplied from the second supply unit 22 b to the second circulation flow path 62. (c) A portion of the medium is discarded from the second circulation flow path 62 to the waste liquid storage unit 26 via the second waste liquid flow path 78.

[0165] In the seventh culture form, as in the third culture form, the formulas (1) to (6), (8), (9), and (13) are used. However, in the seventh culture form, as in the fifth culture form, a basal medium is used instead of a complete medium. In other words, the formula (2) becomes the formula (2)'.

[0166] According to the seventh culture form, as with the fifth culture form, waste products accumulated in the first region 44 can be disposed of in the waste liquid storage section 26 without significantly changing the protein concentration in the first circulation flow path 58.

[0167] [3-2-8 Calculation Method in Eighth Culture Form] The eighth culture form is as follows. The operation of the cell culture device 12 during cell culture in the eighth culture form is the same as the operation of the cell culture device 12 during cell culture in the fourth culture form ( FIG. 15 ), except for the following (a): (a) The basal medium is supplied from the first supply unit 22 a to the first circulation flow path 58. (b) The basal medium is supplied from the second supply unit 22 b to the second circulation flow path 62. (c) A portion of the medium is discarded from the first circulation flow path 58 to the waste liquid storage unit 26 via the first waste liquid flow path 76.

[0168] In the eighth culture form, as in the fourth culture form, the formulas (2) to (5), (8), (9), (10), (12), and (14) are used. However, in the eighth culture form, as in the fifth culture form, a basal medium is used instead of a complete medium. In other words, the formula (2) becomes the formula (2)'.

[0169] According to the eighth culture form, as in the sixth culture form, the concentration of excess protein in the first circulation flow path 58 can be reduced, and waste products accumulated in the first region 44 can be disposed of in the waste liquid storage section 26.

[0170] [3-3 Cell Culture] Figure 16 is a flowchart showing the flow of cell culture performed using the cell culture device 12. The series of steps shown in Figure 16 are performed in step S5 shown in Figure 10. Here, the flow of cell culture of adherent cells will be described.

[0171] In step S11, the control unit 20 performs seeding. The pump control unit 122 controls each pump 98 as shown in FIG. 17 . The clamp control unit 124 controls each clamp 100 as shown in FIG. 17 . The control unit 20 controls the first supply unit 22a to supply the cell solution to the first supply flow path 56. The cell solution is then introduced from the first supply unit 22a through the first supply flow path 56 into the first junction 68 of the first circulation flow path 58. The cell solution introduced into the first junction 68 flows from the first inlet port 48 through the first region 44 and is led to the first outlet port 50. In the first region 44, the cells in the cell solution adhere to the inner surface of each hollow fiber membrane 40 of the bioreactor 30.

[0172] In step S12, the control unit 20 starts cell culture using any one of the first to fourth culture modes. The control unit 20 may also appropriately perform any one of the fifth to eighth culture modes. The control unit 20 controls the first supply unit 22a to supply complete medium to the first supply flow path 56. The complete medium is then introduced from the first supply unit 22a through the first supply flow path 56 into the first junction 68 of the first circulation flow path 58. The complete medium introduced into the first junction 68 circulates through the first circulation flow path 58, which includes the first communication flow path 57, the first inlet port 48, the first region 44, and the first outlet port 50.

[0173] The control unit 20 also controls the second supply unit 22b to supply the basal medium to the second supply flow path 60. The basal medium is then introduced from the second supply unit 22b through the second supply flow path 60 into the second junction 70 of the second circulation flow path 62. The basal medium introduced into the second junction 70 circulates through the second circulation flow path 62, which includes the second communication flow path 61, the second inlet port 52, the second region 46, and the second outlet port 54.

[0174] Furthermore, the gas exchange control unit 126 controls the gas exchange unit 34 to perform gas exchange of the basal medium circulating through the second circulation flow path 62. That is, the gas exchange unit 34 passes a gas of a predetermined component through the basal medium before it flows into the second inlet port 52. This allows the gas concentrations (oxygen gas concentration and carbon dioxide gas concentration) and pH of the basal medium introduced into the second inlet port 52 of the bioreactor 30 to be adjusted to values ​​suitable for cell culture. In the bioreactor 30, the complete medium in the first region 44 and the basal medium in the second region 46 are exchanged through the pores of each hollow fiber membrane 40. This adjusts the gas concentration and pH of the complete medium in the first region 44.

[0175] The clamp control unit 124 also controls the first waste liquid clamp 112 at appropriate timing to open or close the first waste liquid flow path 76. When the first waste liquid flow path 76 is opened, a portion of the complete medium in the first circulation flow path 58 is guided via the first waste liquid flow path 76 to the third waste liquid flow path 80. The clamp control unit 124 also controls the second waste liquid clamp 114 at appropriate timing to open or close the second waste liquid flow path 78. When the second waste liquid flow path 78 is opened, a portion of the basal medium in the second circulation flow path 62 is guided via the second waste liquid flow path 78 to the third waste liquid flow path 80.

[0176] In step S13, the gas sensor 88 measures the oxygen concentration and the carbon dioxide concentration of the culture medium (complete culture medium + basal culture medium). The pH sensor 90 measures the pH of the culture medium. The gas sensor 88 and the pH sensor 90 send the measurement results to the control unit 20. The measurement unit 128 acquires the measurement results from each sensor. The measurement unit 128 stores the acquired measurement results in the first storage unit 120. The gas sensor 88 and the pH sensor 90 continue to measure until the cell culture is completed.

[0177] In step S14, the control unit 20 samples the culture medium. The pump control unit 122 and the gas exchange control unit 126 control the pump (not shown) of the second sampling unit 38 and the clamp (not shown) of the second sampling unit 38 to sample the culture medium in the second circulation flow path 62. The sampled culture medium flows into the waste liquid storage unit 26 via the sensors of the second sampling unit 38. Here, the first sampling unit 35 may sample the basal culture medium.

[0178] In step S15, the glucose sensor 94 measures the glucose concentration in the culture medium. The lactate sensor 96 measures the lactate concentration in the culture medium. The glucose sensor 94 and lactate sensor 96 transmit the measurement results to the control unit 20. The measurement unit 128 acquires the measurement results from each sensor. The measurement unit 128 stores the acquired measurement results in the first storage unit 120. Here, the concentration of the basal culture medium sampled by the first sampling unit 35 may be measured.

[0179] In step S16, the control unit 20 cleans each sensor of the second sampling unit 38. The second sampling unit 38 is provided with one or more pumps (not shown), one or more clamps (not shown), a cleaning liquid supply unit (not shown), etc. The pump control unit 122 controls the pump of the second sampling unit 38. The clamp control unit 124 controls the clamp of the second sampling unit 38. The control unit 20 also controls the cleaning liquid supply unit. Then, cleaning liquid flows from the cleaning liquid supply unit to each sensor of the second sampling unit 38. This cleans each sensor of the second sampling unit 38. The cleaning liquid that has cleaned each sensor of the second sampling unit 38 flows into the waste liquid storage unit 26.

[0180] In step S17, the control unit 20 determines whether or not to terminate the cell culture based on the measurement results obtained by each sensor of the second sampling unit 38. If the control unit 20 determines to terminate the cell culture (step S17: YES), the process proceeds to step S18. On the other hand, if the control unit 20 determines to continue the cell culture (step S17: NO), the process returns to step S14.

[0181] In step S18, the control unit 20 performs cell detachment. The pump control unit 122 turns off the second supply pump 106 and the second circulation pump 108, as shown in FIG. 18 . The clamp control unit 124 also controls the first waste liquid clamp 112 and the second waste liquid clamp 114 to close the first waste liquid flow path 76 and the second waste liquid flow path 78, as shown in FIG. 18 . The control unit 20 also controls the supply unit 22 to supply the detachment solution to the first supply flow path 56. The detachment solution is then guided from the supply unit 22 through the first supply flow path 56 and the first circulation flow path 58 to the bioreactor 30. In the bioreactor 30, the detachment solution detaches the cultured cells from the inner surface of each hollow fiber membrane 40.

[0182] In step S19, the control unit 20 recovers the cells. As shown in FIG. 19 , the clamp control unit 124 controls the recovery clamp 110 to open the recovery channel 64. Then, the liquid containing the cells in the first circulation channel 58 is guided to the recovery container 24 via the recovery channel 64. This completes the series of cell culture steps.

[0183] As shown in FIG. 10 , steps S1 to S6 may be repeated. For example, steps S1 to S6 are performed N times (N≧2). In step S1 for the Nth time, the measurement results from the cell culture process in step S5 for the (N−1)th time may be used as proliferation data. In this case, the acquisition unit 140 of the simulation unit 132 acquires measurement result data from the first storage unit 120 of the control unit 20. However, the glucose measurement results and lactate measurement results stored in the first storage unit 120 are concentration data. Furthermore, the oxygen measurement results and carbon dioxide measurement results stored in the first storage unit 120 are partial pressure data. When the (N−1)th time measurement result is specified by the input unit 130, the acquisition unit 140 converts the concentration data and partial pressure data into metabolic rate data. The simulation execution unit 142 simulates cell culture using the converted data.

[0184] [4 Other Embodiments] Fig. 20 is a diagram showing the configuration of a simulation system 280. The simulation system 280 shown in Fig. 20 may be used instead of the simulation device 14 shown in Fig. 3. In Fig. 20, the same components as in Fig. 3 are denoted by the same reference numerals. The simulation system 280 includes at least one first terminal 282, at least one second terminal 284, and a server 286.

[0185] The first terminal 282 may be a personal computer, a smartphone, a tablet, or the like. The first terminal 282 has an input unit 130, a calculation unit 136a, and a display unit 134. The calculation unit 136a has a processing circuit such as a processor. The processor functions as the display control unit 144 by executing a program stored in a memory (not shown). The first terminal 282 is connected to a communication network 288 via a communication device (not shown).

[0186] A personal computer, a smartphone, a tablet, or the like may be used as the second terminal 284. The second terminal 284 has a control unit 20. The second terminal 284 is connected to a communication network 288 via a communication device (not shown).

[0187] The server 286 includes a simulation unit 132. The server 286 is connected to a communication network 288 via a communication device (not shown). The server 286 may be a cloud server.

[0188] The communication network 288 may be a local area network (LAN) or a wide area network (WAN). The first terminal 282, the second terminal 284, and the server 286 can communicate with each other via the communication network 288.

[0189] When the user operates the input unit 130 to input data, the first terminal 282 transmits each piece of data to the server 286. The simulation execution unit 142 of the server 286 performs a simulation using the data acquired from the first terminal 282. The server 286 transmits the simulation results to the first terminal 282. The first terminal 282 acquires the simulation results from the server 286. The display control unit 144 displays the simulation results on the display unit 134. The second terminal 284 is able to acquire data from the server 286.

[0190] [5. Effects] In the above embodiment, the simulation is performed using not only the supply rate (F_i_b) and the degradation rates (L_i_b1, L_i_b2) but also the exchange rates (E_t_m1, E_t_m2). Therefore, according to the above embodiment, the accuracy of the simulation of changes in protein concentration can be improved. By reflecting the results of the simulation in actual culture, the user can appropriately control the amount of protein.

[0191] Furthermore, in the above embodiment, the simulation is performed using the consumption rate (L_b_c), which makes it possible to further improve the accuracy of the simulation of changes in protein concentration.

[0192] Furthermore, in the above embodiment, the simulation is performed using the discard rates (L_t_w1, L_t_w2). Therefore, according to the above embodiment, the accuracy of the simulation of the change in protein concentration can be further improved.

[0193] [6. Simulation Example] Based on the above-described embodiment, the inventors actually performed a simulation of protein concentration changes (step S2 in FIG. 10 ). Furthermore, the inventors evaluated the accuracy of the simulation by comparing the predicted (calculated) values ​​obtained by the simulation with the measured values ​​measured in actual cell culture. While protein concentration is less likely to change during the culture process of adherent cells, it changes easily during the culture process of suspension cells. Therefore, the inventors evaluated the accuracy of the simulation for the culture process of suspension cells. As a result, the error between the predicted (calculated) protein concentration and the measured protein concentration was within the acceptable range (±5% × day or less). Based on this, the inventors concluded that the simulation of protein concentration changes was appropriate. Below, an example of the simulation is described.

[0194] The cell culture device 12 used in the cell culture experiments was a Quantum cell growth system (manufactured by Terumo BCT) or a Quantum Flex cell growth system (manufactured by Terumo BCT). Hereinafter, the Quantum cell growth system will be referred to as the "first culture device," and the Quantum Flex cell growth system will be referred to as the "second culture device." The first and second culture devices differ in the size of the bioreactor 30. The size of the bioreactor 30 in the second culture device is 1 / 10 of the size of the bioreactor 30 in the first culture device. Note that the size of the bioreactor 30 in at least one of the first and second culture devices may be adjustable. The molecular weight cutoff of the hollow fiber membrane 40 provided in the culture device is preferably 5 to 20 kDa. The molecular weight cutoff of the hollow fiber membrane 40 in the first and second culture devices is approximately 17 kDa.

[0195] [6-1 Identifying Parameters] In order to perform a simulation, it is necessary to identify the parameter information 145 shown in FIG. 4. Therefore, before performing a simulation, the inventors identified the numerical values ​​of the parameter information 145 for several types of proteins. FIG. 21 shows the results of identifying the numerical values ​​of the parameter information 145. FIG. 21 is a table showing specific examples of the numerical values ​​of the parameter information 145. The proteins for which numerical values ​​were identified are albumin (total protein), bFGF, IGF, IL-2, IL-7, and IL-15. The method for identifying the numerical values ​​of each parameter is described below.

[0196] [6-1-1 Method for Determining Deterioration Rate] The inventors placed a medium containing a predetermined concentration of protein in a temperature environment of 37°C and measured the protein concentration after a predetermined time had passed. Based on the predetermined concentration and the measured concentration, the inventors determined the value of "protein deterioration rate at 37°C" in the parameter information 145. Furthermore, the inventors determined the value of "protein deterioration rate at 22°C" in the parameter information 145 using a method similar to the method for determining "protein deterioration rate at 37°C."

[0197] [6-1-2 Method for Determining Inflow and Outflow Rates] The inventors operated the first culture device so that the flow path through which the culture medium flows was the same as that of the first culture mode described in [3-2-1] above. At this time, a culture medium containing protein but not cells was set in the first supply unit 22a. The inventors performed the supply and disposal of culture medium according to the first culture mode for a predetermined period. Furthermore, the inventors periodically performed sampling using the first sampling unit 35 and the second sampling unit 38 to measure the protein concentration in each culture medium. Based on the measurement results, the inventors determined the values ​​of the "protein inflow and outflow rates as seen from inside the bore" and the "protein inflow and outflow rates as seen from outside the bore."

[0198] [6-1-3 Method for Determining Adsorption Rate] The inventors calculated the protein concentration (Pro_IC) in the first circulation flow path 58 based on the formulas (1) to (5) described in [3-2-1] above. The value of the "protein degradation rate at 37°C" determined in [6-1-1] above was substituted for Deg_37. The value of the "protein degradation rate at 22°C" determined in [6-1-1] above was substituted for Deg_22. The value of the "protein inflow and outflow rate as seen from the inner hole" determined in [6-1-2] above was substituted for k_EtoI. Meanwhile, any value equal to or greater than 1 (e.g., 0%, 10%, ..., 90%, 100%, etc.) was substituted for A_r, which corresponds to the adsorption rate in the parameter information 145. Furthermore, the inventors obtained a concentration line (referred to as a predicted concentration line) showing the transition of predicted (calculated) values ​​of protein concentration over a predetermined period. A predicted concentration line is obtained for each value substituted into A_r. Similarly, the inventors obtained a concentration line (referred to as a measured concentration line) showing the transition of measured values ​​of protein concentration over a predetermined period.

[0199] Next, the inventors compared the predicted concentration curve obtained for each A_r with the measured concentration curve. The inventors selected the predicted concentration curve that was closest to the measured concentration curve, and identified A_r corresponding to the selected predicted concentration curve as the “adsorption rate” included in the parameter information 145.

[0200] The numerical values ​​shown in FIG. 21 were determined by the methods described above in [6-1-1] to [6-1-3]. The numerical value of the temperature degradation of a protein depends on the protein manufacturer. Furthermore, the numerical value of the adsorption rate depends on the configuration of the bioreactor 30 of the culture device. In this way, the numerical values ​​of the parameter information 145 change due to various factors. In other words, the numerical values ​​shown in FIG. 21 are not specific values ​​for each protein, but are reference values.

[0201] Cell culture experiments and simulations to identify parameters revealed the following. As a result, it was possible to determine specific "degradation rates," "exchange rates" (values ​​for "protein inflow and outflow rates as seen from inside the bore" and "protein inflow and outflow rates as seen from outside the bore"), and "correction factors (adsorption rates)" for various proteins. For albumin (total protein) larger than the molecular weight cutoff of the hollow fiber membrane 40, the predicted concentration curves and measured concentration curves generally coincided. For proteins with molecular weights equal to or smaller than the molecular weight cutoff of the hollow fiber membrane 40, the concentrations tended to increase in both the first circulation flow path 58 and the second circulation flow path 62, and the predicted concentration curves and measured concentration curves generally coincided. For proteins other than albumin (total protein), the predicted values ​​tended to be higher than the measured values. Assuming that proteins are adsorbed within the flow path, the correction factor (adsorption rate) can be calculated as the ratio showing a concentration similar to the measured value.

[0202] [6-2 Simulation of changes in protein concentration] After determining the values ​​shown in Figure 21, the inventors evaluated the accuracy of the simulation for each of the cell cultures using the first culture device and the second culture device.

[0203] [6-2-1 Accuracy Evaluation 1] The inventors conducted three cell culture experiments using the first culture device under different culture conditions to generate three suspension cell specimens (specimen 1, specimen 2, and specimen 3). In each of the three cell culture experiments, the cells were cultured for seven days, and the protein concentration was measured periodically. Separately, the inventors conducted a simulation of changes in protein concentration based on the culture conditions for each of the three specimens.

[0204] The conditions for the three cell culture experiments and three simulations are as follows: Jurkat cells were used as the suspension cells to be cultured. A complete medium containing total protein was used as the protein. The cell culture circuit 16 was primed with PBS, and after priming, a bag filled with the complete medium was connected to the first supply flow path 56. Gas conditioning was performed, and cells were seeded into the first circulation flow path 58. During the initial cell culture period (7 days), a series of processes consisting of a cell culture step using the first culture configuration, a cell dispersion step, and a cell collection step were repeatedly performed. In the cell dispersion step, the supply and discharge of the medium were stopped, and the medium was circulated within the first circulation flow path 58. In the cell collection step, cells dispersed in the first circulation flow path 58 during the cell dispersion step were collected inside the bioreactor 30. Here, the cell collection step was performed using the fifth culture configuration. During the cell dispersion process, all clamps 100 (collection clamp 110, first waste liquid clamp 112, second waste liquid clamp 114, and third waste liquid clamp 116) are closed. In this state, no change in protein concentration occurs. Therefore, there is no formula for calculating the protein concentration corresponding to the cell dispersion process. During the middle to late stages of the cell culture period (7 days), a series of processes consisting of the cell culture process using the third culture form, the cell dispersion process, and the cell collection process were repeated. Here, the cell collection process was performed using the fifth culture form.

[0205] 22 to 24 are tables showing culture conditions. FIG. 22 shows the culture conditions for specimen 1. FIG. 23 shows the culture conditions for specimen 2. FIG. 24 shows the culture conditions for specimen 3. The "IC supply flow rate" shown in each table is the flow rate of the complete medium supplied to the first circulation flow path 58 by the first supply pump 102. The "IC supply flow rate" corresponds to IC_ir in the above equation (2) explained in [3-2-1] above. The "EC supply flow rate" shown in each table is the flow rate of the basal medium supplied to the second circulation flow path 62 by the second supply pump 106. The "EC supply flow rate" corresponds to EC_ir in the above equation (13) explained in [3-2-3] above.

[0206] As shown in Figures 22 to 24, the flow rates of the complete medium and basal medium and the timing of switching from the first culture mode to the third culture mode differed in the three cell culture experiments. In each table, a period in which the "EC supply flow rate" is 0 indicates that the first culture mode was being performed. In each table, a period in which the "EC supply flow rate" is other than 0 indicates that the third culture mode was being performed.

[0207] 25 to 27 are graphs showing the change in protein concentration in the first circulation flow path 58. The graph in FIG. 25 shows the change in protein concentration in an experiment in which sample 1 was cultured. The graph in FIG. 26 shows the change in protein concentration in an experiment in which sample 2 was cultured. The graph in FIG. 27 shows the change in protein concentration in an experiment in which sample 3 was cultured. In FIGS. 25 to 27, the solid line graphs are measured concentration lines showing the change in measured values ​​of protein (total protein). The dashed line graphs are predicted concentration lines showing the change in predicted (calculated) values ​​of protein (total protein) concentration. The dashed-dotted line graphs are lines showing the upper limit of the allowable error range for the predicted value relative to the measured value. The dashed-dotted line graphs are lines showing the lower limit of the allowable error range for the predicted value relative to the measured value. Note that the allowable error range is set to ±5% × day.

[0208] As shown in Figures 25 to 27, the predicted concentration lines for each of the samples 1 to 3 generally fell within the allowable error range (between the lower and upper limits). That is, the predicted concentration lines for each of the samples 1 to 3 fell within the range of ±5% × day of the measured concentration line during the middle to late stages of culture (from day 4 onwards), when cell proliferation was active. The predicted concentration lines for each of the samples 1 to 3 fell within the range of ±5% × day of the measured concentration line on the final day of culture.

[0209] [6-2-2 Accuracy Evaluation 2] The inventors conducted a cell culture experiment using the second culture device to generate a suspension cell specimen. In this experiment, the cells were cultured for 7 days, and the protein concentration was measured periodically. Separately, the inventors performed a simulation of changes in protein concentration based on the specimen culture conditions.

[0210] The conditions for carrying out the cell culture experiment and simulation are as follows: Jurkat cells were used as the suspension cells to be cultured. A complete medium containing total protein was used as the protein. Gas conditioning was performed, and the cells were seeded in the first circulation channel 58. A series of processes consisting of a cell culture step using the first culture form, a cell dispersion step, and a cell collection step were repeated throughout the entire cell culture period (7 days). Here, the cell collection step was carried out using the first culture form.

[0211] Fig. 28 is a table showing culture conditions. Fig. 29 is a graph showing the change in protein concentration in the first circulation flow path 58. In Fig. 29, the dashed line is a predicted concentration line showing the change in predicted (calculated) protein (total protein) concentration. The dashed line is a line showing the upper limit of the allowable error range for the predicted value relative to the measured value. The dashed line is a line showing the lower limit of the allowable error range for the predicted value relative to the measured value. Note that the allowable error range is set to ±5% × day here.

[0212] As shown in Figure 29, the predicted concentration lines for the samples generally fell within the acceptable error range (between the lower and upper limits). That is, the predicted concentration lines for the samples fell within the range of ±5% × day of the measured concentration line during the middle to late stages of culture (from day 3 onwards), when cell proliferation was active. The predicted concentration lines for the samples fell within the range of ±5% × day of the measured concentration line on the final day of culture.

[0213] As described above, in both of the accuracy evaluations using two different-sized culture devices (Accuracy Evaluations 1 and 2), the error in the predicted values ​​relative to the measured values ​​of protein concentration was within the acceptable range. Based on this, the inventors concluded that the simulation of protein concentration changes was appropriate.

[0214] The simulation is not affected by culture conditions, and protein concentration simulation is possible without being affected by the combination of multiple culture forms, switching between multiple culture forms, or culture scale.

[0215] [6-3 Example of Cell Culturing of Adherent Cells] In the above-mentioned accuracy evaluations 1 and 2, the measured protein concentrations in the cell culture experiment (example) for suspension cells were compared with the predicted (calculated) protein concentrations in the simulation. When culturing adherent cells, the following example may be performed, for example: HEK293 cells are used as the adherent cells to be cultured. A complete medium containing total protein is used as the protein. After priming the cell culture circuit 16 with PBS, the cell culture circuit 16 is precoated with cellular adhesion factors (vitronectin and fibronectin), and a bag filled with the complete medium after precoating is connected to the first supply flow path 56. Gas conditioning is performed, and cells are seeded into the first circulation flow path 58. During the early stage of the cell culture period, a cell culture process using the second culture type is performed. During the middle to late stages of the cell culture period, a cell culture process using the fourth culture type is performed.

[0216] In the second and fourth culture forms, which are culture forms for adherent cells, complete medium is supplied to the first circulation channel 58, and the medium is discarded from the first circulation channel 58 to the waste liquid storage section 26 via the first waste liquid channel 76. In other words, the medium is not discarded from the second circulation channel 62. Therefore, the protein concentration in the first circulation channel 58 is approximately constant.

Claims

1. A simulation device that performs a simulation regarding cell growth in a cell culture device in which a medium containing a protein is supplied to an inner circulation path, which is a circulation path including an inner hole of a cylindrical hollow fiber membrane, and cells are cultured in the inner hole, the simulation device comprising a simulation execution unit that performs the simulation regarding the change in concentration of the protein in the inner circulation path accompanying cell growth under specified culture conditions using at least a supply rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to the supply of medium to the inner circulation path, an exchange rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to the inflow and outflow of medium between the inside and the outside of the inner hole via the hollow fiber membrane, and a degradation rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to degradation of the protein.

2. A simulation device according to claim 1, further comprising a display control unit that causes a display unit to display information corresponding to the concentration change obtained by the simulation.

3. A simulation device according to claim 1 or 2, wherein the simulation execution unit executes the simulation of the change in concentration of the protein in the inner circulation path further using a consumption rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to consumption of the protein by cells.

4. A simulation device as claimed in claim 1 or 2, wherein, when a portion of culture medium is discarded through the inner circulation path during cell cultivation, the simulation execution unit further uses a discard rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to the discard of a portion of the culture medium through the inner circulation path, to execute the simulation of the change in concentration of the protein in the inner circulation path.

5. A simulation device according to claim 1 or 2, wherein the simulation execution unit executes the simulation of the change in concentration of the protein within the inner circulation path, further using an adsorption rate, which is the proportion of the protein that cannot be consumed by cells due to the protein being adsorbed, aggregated, and deposited in at least one of the inside of the inner circulation path and the inside of an outer circulation path, which is a circulation path including the area between the hollow fiber membrane and a housing that contains the hollow fiber membrane.

6. A simulation device according to claim 1 or 2, wherein the cell culture device is capable of supplying a culture medium not containing the protein to an outer circulation path, which is a circulation path including the area between the hollow fiber membrane and a housing that contains the hollow fiber membrane.

7. A simulation device according to claim 6, wherein, when culturing adherent cells, the cell culture device is capable of discarding culture medium through a waste liquid flow path connected to the inner circulation path.

8. A simulation device according to claim 6, wherein, when culturing suspended cells, the cell culture device is capable of discarding culture medium through a waste liquid flow path connected to the outer circulation path.

9. A simulation device according to claim 1 or 2, wherein the cell culture apparatus comprises an outer circulation path which is a circulation path including the inside of the inner circulation path and the area between the hollow fiber membrane and a housing which accommodates the hollow fiber membrane, and when a portion of the culture medium is discarded via the outer circulation path during cell culture, the simulation execution unit executes the simulation of the change in concentration of the protein in the outer circulation path accompanying cell proliferation under the culture conditions using at least a discard rate, which is a rate at which the concentration of the protein changes in the outer circulation path due to the discard of a portion of the culture medium via the outer circulation path, the exchange rate, and the deterioration rate.

10. A simulation system that performs a simulation regarding cell growth in a cell culture device in which a medium containing a protein is supplied to an inner circulation path, which is a circulation path including an inner hole of a cylindrical hollow fiber membrane, and cells are cultured in the inner hole, the simulation system comprising: a simulation execution unit that performs the simulation regarding the change in concentration of the protein in the inner circulation path accompanying cell growth under specified culture conditions using at least a supply rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to the supply of medium to the inner circulation path, an exchange rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to the inflow and outflow of medium between the inside and the outside of the inner hole via the hollow fiber membrane, and a degradation rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to degradation of the protein; and a display control unit that causes information corresponding to the concentration change obtained by the simulation to be displayed on a display unit.

11. A simulation method for performing a simulation of cell growth in a cell culture device in which a medium containing a protein is supplied to an inner circulation path, which is a circulation path including an inner hole of a cylindrical hollow fiber membrane, and cells are cultured in the inner hole, the simulation method comprising a simulation step of performing the simulation of the change in concentration of the protein in the inner circulation path accompanying cell growth under specified culture conditions using at least a supply rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to the supply of medium to the inner circulation path, an exchange rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to the inflow and outflow of medium between the inside and the outside of the inner hole via the hollow fiber membrane, and a degradation rate, which is the rate at which the concentration of the protein changes in the inner circulation path due to degradation of the protein.

12. A simulation method according to claim 11, further comprising a display step of displaying information corresponding to the concentration change obtained by the simulation on a display unit.

13. A simulation method according to claim 11 or 12, wherein in the simulation step, the simulation of the change in concentration of the protein in the inner circulation path is performed further using a consumption rate, which is a rate at which the concentration of the protein changes in the inner circulation path due to consumption of the protein by a cell.

14. A simulation method according to claim 11 or 12, wherein, when a portion of the culture medium is discarded via the inner circulation path during cell cultivation, the simulation step further uses a discard rate, which is a rate at which the concentration of the protein changes in the inner circulation path due to the discard of a portion of the culture medium via the inner circulation path, to perform the simulation of the change in concentration of the protein in the inner circulation path.

15. A simulation method according to claim 11 or 12, wherein in the simulation step, the simulation of the change in concentration of the protein within the inner circulation path is performed further using an adsorption rate, which is the proportion of the protein that cannot be consumed by cells due to the protein being adsorbed, aggregated, and deposited in at least one of the inside of the inner circulation path and the inside of an outer circulation path, which is a circulation path including the area between the hollow fiber membrane and a housing that contains the hollow fiber membrane.

16. A simulation method according to claim 11 or 12, wherein the cell culture device is capable of supplying a medium not containing the protein to an outer circulation path, which is a circulation path including an area between the hollow fiber membrane and a housing that contains the hollow fiber membrane.

17. A simulation method according to claim 16, wherein, when culturing adherent cells, the cell culture device is capable of discarding culture medium via a waste liquid flow path connected to the inner circulation path.

18. A simulation method according to claim 16, wherein, when culturing suspended cells, the cell culture device is capable of discarding culture medium via a waste liquid flow path connected to the outer circulation path.

19. A simulation method according to claim 11 or 12, wherein the cell culture apparatus comprises an outer circulation path which is a circulation path including the interior of the inner circulation path and the area between the hollow fiber membrane and a housing which accommodates the hollow fiber membrane, and when a portion of the culture medium is discarded via the outer circulation path during cell culture, the simulation step performs the simulation of the change in concentration of the protein in the outer circulation path accompanying cell proliferation under the culture conditions using at least a discard rate, which is a rate at which the concentration of the protein changes in the outer circulation path due to the discard of a portion of the culture medium via the outer circulation path, the exchange rate, and the deterioration rate.

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