Method for designing platelet production apparatus

Abstract

To provide a method for designing a large-scale platelet production apparatus using a reciprocating agitator blade, in which the platelet production efficiency is not reduced by enlarging the apparatus based on the shape of a small-scale production apparatus so as to satisfy geometric similarity conditions.SOLUTION: The method for designing the platelet production apparatus of the present invention is characterized in that, when designing a novel agitator with a predetermined production capacity larger than a predetermined range, which is agitated by a reciprocating agitator blade 3, based on the shape of an agitator as the base of a production capacity within the predetermined range designed to achieve a predetermined platelet production efficiency, the shape of the novel agitator is designed to be larger than the shape of the agitator as the base so as to satisfy geometric similarity conditions, and a novel agitator blade 4 is added above the agitator blade provided on the agitator as the base.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention is a design method for a platelet production device (production apparatus), and particularly relates to a method for designing a large-scale production device with an increased production capacity based on a small-scale production device in a platelet production device (agitation device) using a reciprocating agitation blade.

Background Art

[0002] (1. Description of Conventional Platelet Production Devices)

[0003] A method for producing (manufacturing) platelets from cultured megakaryocytes has been developed. Also, by using an agitation blade disposed in a culture vessel and reciprocating the agitation blade to agitate the culture solution while culturing megakaryocytes, it has been found that the production efficiency (or the number of platelets) of platelets can be increased.

[0004] In addition, in the culture of megakaryocytes, turbulent flow energy, shear stress, etc. in the culture vessel are highly involved. The number, shape of the reciprocating agitation blades, the fixed position with respect to the drive shaft, etc. are set so that these turbulent flow energies, etc. become a predetermined turbulent flow energy, etc. that results in the optimal platelet production efficiency.

[0005] For example, FIG. 5 shows a reciprocating agitation device set to increase the platelet production efficiency. 1 is, for example, a bottomed cylindrical culture vessel, 2 is a reciprocating drive shaft vertically or horizontally provided in the culture vessel, and 3 is a reciprocating agitation blade provided on the drive shaft 2 either singly or in a plurality of stages at a predetermined distance apart.

[0006] Also, the drive shaft 2 is provided to reciprocate in the axial direction, for example, in the vertical direction or the horizontal direction, by a reciprocating drive device (not shown).

[0007] Note that the shape of each stirring blade 3 is not particularly limited. For example, it can be made of plate bodies of various shapes such as circular, elliptical, rectangular, etc. In addition to flat plate bodies, there are also plate bodies bent in the middle of the plate body.

[0008] In addition, each of the stirring blades 3 may be provided at a predetermined angle and inclined, in addition to being provided such that its surface is perpendicular to the reciprocating direction of the drive shaft 2.

[0009] In addition, one or a plurality of openings may be formed in the stirring blade 3.

[0010] (2. Method for Designing a Stirring Device from a Small-Scale Stirring Device to a Large-Scale Stirring Device)

[0011] In addition, when designing (manufacturing) a stirring device to increase the production capacity (scale-up), in addition to the method of newly designing, for example, by enlarging the shape of a small-scale stirring device set to increase the production efficiency of platelets so as to satisfy the geometric similarity conditions, in a large-scale stirring container, it is possible to maintain the same platelet production efficiency as that of the small-scale stirring device.

[0012] That is, for example, for a small-scale stirring device with a production capacity of 500 mL of a culture container, the shape of the stirring device, for example, the shape of the culture container (including the size), and the shape of the stirring means (the number of stirring blades, the shape (including the size), and the fixed position with respect to the drive shaft, etc.) are designed so as to achieve the desired optimal platelet production efficiency.

[0013] Note that a small-scale stirring device with a production capacity of 500 mL, which was designed and used in the past with the desired optimal platelet production efficiency, may be used.

[0014] And when increasing the production capacity from the 500 mL, by enlarging the shape of the 500 mL stirring device so as to satisfy the geometric similarity conditions, the desired optimal platelet production efficiency can be maintained, so that the scale-up of the platelet manufacturing device can be facilitated.

[0015] For example, as methods for manufacturing platelets, there are Patent Document 1 and Patent Document 2.

Prior Art Documents

Patent Documents

[0016]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0017] However, for example, when the production capacity of the culture vessel at the laboratory level is from 500 mL to 3 L, under geometric scale conditions, by increasing the shape of the stirring device, for example, the shape of the culture vessel and the shape of the stirring means, etc., the desired optimal platelet production efficiency could be maintained. However, when the capacity required for practical use is 8 L or more, 10 L or more, or 45 L or more, although the functionality could be maintained, a decrease in platelet production efficiency was confirmed.

[0018] Therefore, in order to find the cause, the inventor of the present application compared the scale-up factors during scale-up in a bioreactor using CFD simulation.

[0019] That is, based on a stirring device with a production capacity of 2.4 L (VerMES3) designed with the shape of the culture vessel (bottomed cylindrical vessel) and the shape of the stirring means (elliptical stirring blades in two upper and lower stages separated by a desired distance) where the platelet production efficiency becomes the desired optimum, under geometric similarity conditions, the flow pattern, turbulent energy, and shear stress states were simulated in a stirring device with a production capacity of 8 L (VerMES10) and a stirring device with a production capacity of 45 L (VerMES50) that were enlarged.

[0020] As a result, when the stirring device with a production capacity of 2.4 L is scaled up under the geometric similarity conditions as described above, as shown in Fig. 6 showing the flow pattern, when the production capacity is 8 L and 45 L, a stagnant flow portion A occurs at the upper part of the tank, and it was found that as the production capacity increases, the stagnant flow portion increases at the upper part of the tank.

[0021] Also, as shown in Figs. 7 and 10 showing the turbulent kinetic energy, when the liquid level is up to the 60% - 70% level, the turbulent kinetic energy is substantially the same regardless of the production capacity. However, when it is 60% or more, or 70% or more, a portion A where the turbulent kinetic energy of 8 L and 45 L production capacities significantly decreases occurs at the upper part of the tank compared to the case where the production capacity is 2.4 L, and it was found that as the production capacity increases, the portion where the turbulent kinetic energy decreases increases at the upper part of the tank.

[0022] Also, as shown in Figs. 8 and 9 showing the shear stress, when the liquid level is up to about 60% - 70%, the shear stress is substantially the same regardless of the production capacity. However, when it is 60% or more, or 70% or more, a portion A where the shear stress of 8 L and 45 L production capacities significantly decreases occurs at the upper part of the tank compared to the case where the production capacity is 2.4 L, and it was found that as the production capacity increases, the portion where the shear stress decreases increases at the upper part of the tank.

[0023] From the above, it was found that when the production capacity exceeds a predetermined size, the volume of the upper part of the tank with low shear stress and turbulent kinetic energy, which is essential for platelet production, increases according to the scale.

[0024] This region is lost as the production volume, and as a result, the platelet production amount decreases as the scale-up progresses. Therefore, a device that applies the physical stress required for platelet production to this region regardless of the scale is required.

[0025] The present invention is based on the above findings.

Means for Solving the Problems

[0026] To achieve the above object, the method for designing a platelet manufacturing apparatus of the present invention is based on the shape of a stirring device that is stirred by a reciprocating stirring blade and serves as a basis for a production capacity within a predetermined range designed to achieve a predetermined platelet production efficiency. When designing a new stirring device with a predetermined production capacity greater than the predetermined range and stirred by a reciprocating stirring blade, based on the shape of the stirring device serving as the basis, the shape of the new stirring device is designed to be enlarged so as to satisfy the geometric similarity conditions, and a new stirring blade is designed to be added above the stirring blade provided in the stirring device serving as the basis.

[0027] Further, when the stirring device serving as the basis is designed based on another stirring device, the new stirring device is characterized in that it is designed based on the stirring device serving as the basis or the other stirring device.

[0028] Further, when the stirring device serving as the basis is designed based on another stirring device, and the other stirring device is designed based on yet another stirring device, and so on, and is designed by a plurality of continuous stirring devices, the new stirring device is characterized in that it is designed by either the stirring device serving as the basis or the other stirring device.

[0029] Further, the shape of the stirring device is characterized by comprising the shape of the culture vessel, the number, size, and position fixed to the drive shaft of the stirring blades, and the shape of the stirring means.

[0030] Further, the production capacity within the predetermined range is set based on the flow state, or turbulent energy, or shear stress with respect to the liquid level of a small-scale stirring device with a predetermined production capacity and a large-scale stirring device with a production volume greater than the plurality of predetermined production capacities, which is designed to be enlarged so as to satisfy only the geometric similarity conditions based on the shape of the small-scale stirring device.

[0031] Also, the production capacity within the predetermined range is greater than 0L and within the range of 3L or less, and the predetermined production capacity greater than the predetermined range is 8L or more.

[0032] Also, the additional stirring blade is an elliptical blade or a rectangular blade fixed to the drive shaft so as to cross the stirring blade below it.

[0033] Also, the major axis direction of the additional stirring blade is provided so as to cross within a predetermined range with respect to the major axis direction of the stirring blade below it.

[0034] Also, when there are a plurality of the additional stirring blades, the major axis direction of each of the additional stirring blades is provided so as to cross within a predetermined range with respect to the major axis direction of the stirring blade below it, respectively.

[0035] Also, when there are a plurality of the stirring blades of the basic stirring device, the major axis direction of each stirring blade except the lowermost stirring blade is provided so as to cross within a predetermined range with respect to the major axis direction of the stirring blade below it, respectively, and the major axis direction of the additional stirring blade is provided so as to cross within a predetermined range with respect to the major axis direction of the stirring blade below it.

[0036] Also, when there are a plurality of the stirring blades of the basic stirring device, the major axis direction of each stirring blade except the lowermost stirring blade is provided so as to cross within a predetermined range with respect to the major axis direction of the stirring blade below it, respectively, and when there are a plurality of the additional stirring blades, the major axis direction of each of the additional stirring blades is provided so as to cross within a predetermined range with respect to the major axis direction of the stirring blade below it, respectively.

[0037] The predetermined range is characterized by being 10° to 170°.

[0038] Also, the diameter of the stirring blade added upward is the same as or larger than the diameter of the stirring blade below the added stirring blade.

[0039] In addition, when a stirring blade is added to the stirring device that is the basis of the two-stage blade, the diameter of the stirring blade between the added stirring blade and the lowermost stirring blade is in the range of 100 to 50% of the diameter of the added stirring blade or the diameter of the lowermost stirring blade, and is the same as or smaller than that.

Advantages of the Invention

[0040] According to the present invention, there is an advantage that a large-scale culture device can be designed based on the shape of a small-scale culture device while maintaining optimal platelet production efficiency.

[0041] In addition, when designing a stirring device with a large-scale production capacity at the practical level, there is no need to newly redesign it. Simply based on the shape of the small-scale stirring device, it can be enlarged under geometric similarity conditions and a large-scale stirring device can be designed by simply adding a stirring blade.

Brief Description of the Drawings

[0042]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

[0043] Examples of modes for carrying out the present invention are shown below. [Example]

[0044] A first embodiment of the present invention will be described with reference to Figures 1 to 4. Note that the same parts as those in the conventional description are given the same reference numerals and their description will be omitted.

[0045] (3. Overall structure)

[0046] As a result of various experiments, it was found that when a large-scale platelet production device is designed based on a small-scale agitator, and the production capacity of the large-scale agitator is in the laboratory level range of 3 L or less, the optimum platelet production efficiency can be maintained by designing the small-scale designed agitator shape (e.g., the shape of the culture vessel and the shape of the agitation means) to be larger so as to satisfy the geometric similarity condition, so that the optimum platelet production efficiency can be maintained.

[0047] However, for example, when designing a culture device for a production capacity exceeding 3 L (large scale), such as 8 L or more, or 10 L or more, or 45 L or more, based on the shape of a stirring device with a production capacity of 3 L or less (small scale), in the present invention, based on the shape of the stirring device (e.g., the shape of the culture vessel and the shape of the stirring means) designed on the small scale, which can optimize the production efficiency of platelets, it is enlarged under geometric similarity conditions. Further, as shown in FIG. 1, an additional reciprocating stirring blade 4 is fixed to the drive shaft 2 above the uppermost stirring blade 3 of the stirring device 1 on the small scale to compensate for the reduced turbulent energy and shear stress and optimize the production efficiency (number of platelets) of platelets.

[0048] Note that the additional stirring blade 4 may be one or more.

[0049] Note that the position where the stirring blade 4 is added to the drive shaft 2 is preferably fixed at a location above the liquid level with a high deviation rate described later, for example, at a location where the liquid level is 60% or 70% or more.

[0050] FIG. 2 shows the relationship between the liquid level and the shear stress in a stirring device with a production capacity of 2.4 L using a two-stage stirring blade, a stirring device with a production capacity of 8 L set to be enlarged to satisfy geometric similarity conditions based on the shape of the 2.4 L stirring device, a stirring device with a production capacity of 45 L, and a culture device with a production capacity of 45 L in a three-stage blade with an additional stirring blade 4 added to the upper part.

[0051] As can be seen from FIG. 2, compared with the shear stress of a small-scale culture device with a production capacity of 2.4 L and a two-stage blade, in the case of a stirring device with a production capacity of not less than 45 L and a two-stage blade, when the liquid level is 60% to 70% or more, the shear stress is significantly reduced. However, by using a three-stage blade, it can be seen that the shear stress of the small-scale culture device with a production capacity of 2.4 L can be recovered to approximately the same level, regardless of the large-scale culture device with a production capacity of 45 L.

[0052] Further, FIG. 3 shows, using CFD simulation, a stirring device with a production capacity of 2.4 L using a two-stage blade stirring blade, and a stirring device with a production capacity of 8 L set to be enlarged to satisfy geometric similarity conditions based on the shape of the 2.4 L stirring device, a stirring device with a production capacity of 45 L, and a culture device with a production capacity of 45 L in a three-stage blade with an additional stirring blade added to the upper part. It is a figure showing the relationship between the liquid level and the turbulent energy in the device.

[0053] Also in this case, similar to the shear stress, compared with the turbulent energy of the culture device with a production capacity of 2.4 L and a two-stage blade, when the production capacity is 45 L and the two-stage blade is used, when the liquid level is 60% to 70% or more, the turbulent energy is greatly reduced. However, it can be seen that by using a three-stage blade, the shear stress can be recovered to approximately the same level.

[0054] In addition, if each of the stirring blades is a reciprocating stirring blade, there is no particular limitation on the shape or the like. For example, there are plate bodies of various shapes such as circular shape, elliptical shape, rectangular shape, etc., a plate body with an overall flat shape, and a plate body bent in the middle.

[0055] In addition, when the production capacity of the scaled-up stirring device is below a certain level, it can be designed only based on the geometric similarity conditions. When the production capacity is above a certain level, regarding whether to add stirring blades or not, for example, based on the shape of the stirring device at a certain scale that can achieve the optimal platelet production efficiency, design a plurality of stirring devices at scales larger than the certain scale to meet the geometric similarity conditions. Then, through experiments or simulations, obtain the flow diagram, turbulent energy value, and shear stress value with respect to the liquid level of each stirring device for the stirring device at the certain scale (hereinafter referred to as the "small scale") and each stirring device at scales larger than the certain scale (hereinafter referred to as the "large scale"). From the obtained diagrams, values, etc., for example, when dissociated by a predetermined amount (or when reaching a predetermined deviation rate), for production capacities below that, design only based on the geometric similarity conditions, and for production capacities above that (or larger than that), determine to add stirring blades.

[0056] In addition, when the deviation rate or the like is above a predetermined value, two or more stirring blades may be added as necessary.

[0057] For example, when the production capacity of the large-scale stirring device is greater than 0 L and 3 L or less, design it only based on the geometric similarity conditions.

[0058] Also, when the production capacity of the small-scale stirring device is 3 L or less and the production capacity of the large-scale stirring device is 8 L or more, or 10 L or more, or 45 L or more, design it to add stirring blades.

[0059] In addition, when successively designing larger-scale stirring devices, such as when designing a medium-scale stirring device with a larger production capacity based on the small-scale stirring device and then designing a large-scale stirring device with an even larger production capacity based on the designed medium-scale stirring device, in addition to designing based on the immediately preceding stirring device, it may also be possible to design the stirring device based on the stirring device designed earlier than the immediately preceding stirring device.

[0060] That is, for example, when the production capacity of a small-scale stirring device is 3 L or less, and the production capacity of a large-scale stirring device is designed to be 5 L, when designing a large-scale stirring device with a production capacity larger than this, for example, 8 L or more, it may be designed based on the 5 L stirring device, or it may also be designed based on a small-scale stirring device with a production capacity of 3 L or less that is the basis for the design of the above 5 L stirring device.

[0061] (4. Description of the additional stirring blades)

[0062] In addition, the additional stirring blades should be arranged so as not to hinder the upper circulation flow of the liquid placed in the culture vessel, and it is preferable to arrange elliptical blades or rectangular blades so that their major axes intersect, such as being orthogonal, with respect to the major axis of the stirring blade below.

[0063] That is, for example, when the stirring blades 3 and 4 of each stage are elliptical blades (excluding circular blades) or rectangular blades, and the direction of the major axis 4a of the additional stirring blade 4 is arranged so as to fall within a predetermined range θ with respect to the direction of the major axis 3a of the stirring blade 3 below, as shown in FIG. 4.

[0064] The predetermined range θ is an angle within a range that does not overlap with the stirring blade below (for example, the tip of the stirring blade), and is, for example, 10° to 170°, preferably 45° to 135°, more preferably 80° to 100°, and even more preferably 90°.

[0065] In addition, when there are a plurality of additional stirring blades, it is preferable that each stirring blade is designed to satisfy the above conditions.

[0066] As described above, by providing the stirring blades with a phase shift relative to the lower stirring blades, the pressure balance is disrupted, making it easier to form an upward flow and preventing the inhibition of the circulation flow. In the large-scale stirring device designed based on the small-scale stirring device, it becomes possible to maintain the optimal platelet production efficiency.

[0067] In addition, if the stirring blades at each stage of the small-scale stirring device, which is the basis for the design of the large-scale stirring device, are also arranged so as to fall within the predetermined range θ, in the large-scale stirring device designed based on the small-scale stirring device, it becomes possible to maintain the optimal platelet production efficiency.

[0068] Also, adjust the blade diameter of the added stirring blades so as to obtain appropriate physical stress.

[0069] That is, although it varies depending on the production purpose, the ratio of the blade diameter d to the tank diameter D is preferably in the range of D / d = 0.95 to 0.5.

[0070] Also, it is desirable that the diameter of the stirring blade added upward, for example, the major axis, is the same as or larger than the diameter of the stirring blade below it, for example, the major axis.

[0071] For example, when the large-scale stirring device has three stages of blades, it is desirable that the diameter of the uppermost stirring blade, for example, the major axis, is the same as or larger than the diameter of the middle blade below it, for example, the major axis.

[0072] Also, when the large-scale stirring device has three stages of blades, the diameter of the middle blade, for example, the major axis, between the uppermost stirring blade and the lowermost stirring blade is in the range of 100 to 50% with respect to the diameter of the uppermost stirring blade, for example, the major axis, and the diameter of the lowermost stirring blade, for example, the major axis, respectively, and it is preferable that they have the same diameter or are slightly smaller.

[0073] From the above, it becomes possible to prevent the inhibition of the circulation flow of the liquid in the tank, and in the large-scale stirring device designed based on the small-scale stirring device, it becomes possible to maintain the optimal platelet production efficiency.

[0074] (5. Advantages of the present invention)

[0075] According to the present invention, when the production capacity of the culture vessel is within a range not exceeding a predetermined value, based on the shape of the basic culture apparatus, a scaled-up stirring apparatus can be designed simply by satisfying the geometric similarity conditions. Also, for example, when the production capacity exceeds a predetermined value such as greater than 3 L, or 8 L or more, or 10 L or more, or 45 L or more, etc., while satisfying the geometric similarity conditions, by further adding a stirring blade in the upper stage, there is an advantage that a large-scale culture apparatus can be designed based on the shape of the culture vessel of the small-scale stirring apparatus.

[0076] Also, by setting the added stirring blade at a predetermined position and size, it becomes easier to form an upward flow, etc., and in a large-scale stirring apparatus designed based on a small-scale stirring apparatus, it becomes possible to maintain the same optimal platelet production efficiency as that of the small scale.

Explanation of reference numerals

[0077] 1 Culture vessel 2 Drive shaft 3 Reciprocating stirring blade 3a Major axis 4 Additional reciprocating stirring blade 4a Major axis

Claims

1. Based on the shape of the stirring device that serves as the basis for a production volume within a predetermined range designed to achieve a predetermined platelet production efficiency and is stirred by a reciprocating stirring blade, when designing a new stirring device with a production volume greater than the predetermined range and stirred by a reciprocating stirring blade, based on the shape of the stirring device serving as the basis, design the shape of the new stirring device to be enlarged so as to satisfy the geometric similarity conditions, and design to add a new stirring blade above the stirring blade provided in the stirring device serving as the basis. A method for designing a platelet manufacturing device is characterized by this.

2. When the stirring device serving as the basis is designed based on another stirring device, the new stirring device is designed based on the stirring device serving as the basis or the other stirring device. The method for designing a platelet manufacturing device according to claim 1 is characterized by this.

3. When the stirring device serving as the basis is designed based on another stirring device, and the other stirring device is designed based on yet another stirring device, etc., and is designed by a series of multiple stirring devices, the new stirring device is designed by either the stirring device serving as the basis or the other stirring device. The method for designing a platelet manufacturing device according to claim 1 is characterized by this.

4. The shape of the stirring device comprises the shape of the culture vessel and the shape of the stirring means consisting of the number, size, and position fixed to the drive shaft of the stirring blade. The method for designing a platelet manufacturing device according to claim 1 is characterized by this.

5. The production volume within the predetermined range is a small-scale stirring device with a predetermined production volume and a large-scale stirring device with a production volume greater than the plurality of predetermined production volumes, designed to be enlarged based on the shape of the small-scale stirring device so as to satisfy only the geometric similarity conditions, and is set based on the flow state, or turbulent energy, or shear stress with respect to the liquid level. The method for designing a platelet manufacturing device according to claim 1 is characterized by this.

6. The production volume within the predetermined range is greater than 0 L and within the range of 3 L or less, and the production volume greater than the predetermined range is 8 L or more. The method for designing a platelet manufacturing device according to claim 1 is characterized by this.

7. The design method of the platelet manufacturing apparatus according to claim 1, wherein the stirring blade to be added is an elliptical blade or a rectangular blade fixed to the drive shaft so as to intersect the stirring blade below it.

8. The design method of the platelet manufacturing apparatus according to claim 1, wherein the major axis direction of the stirring blade to be added is provided so as to intersect within a predetermined range with respect to the major axis direction of the stirring blade below it.

9. The design method of the platelet manufacturing apparatus according to claim 1, wherein when there are a plurality of the stirring blades to be added, the major axis direction of each of the added stirring blades is provided so as to intersect within a predetermined range with respect to the major axis direction of the stirring blade below it, respectively.

10. [[ID=(6)]]When there are a plurality of the stirring blades of the base stirring device, the major axis directions of the stirring blades except the lowermost stirring blade are provided so as to intersect within a predetermined range with respect to the major axis direction of the stirring blade below it, respectively, and The design method of the platelet manufacturing apparatus according to claim 1, wherein the major axis direction of the stirring blade to be added is provided so as to intersect within a predetermined range with respect to the major axis direction of the stirring blade below it.

11. When there are a plurality of the stirring blades of the base stirring device, the major axis directions of the stirring blades except the lowermost stirring blade are provided so as to intersect within a predetermined range with respect to the major axis direction of the stirring blade below it, respectively, and The design method of the platelet manufacturing apparatus according to claim 1, wherein when there are a plurality of the stirring blades to be added, the major axis direction of each of the added stirring blades is provided so as to intersect within a predetermined range with respect to the major axis direction of the stirring blade below it, respectively.

12. The design method of the platelet manufacturing apparatus according to any one of claims 6 to 9, wherein the predetermined range is 10° to 170°.

13. The design method of the platelet manufacturing apparatus according to claim 1, wherein the diameter of the stirring blade added upward is the same as or larger than the diameter of the stirring blade below the added stirring blade.

14. When a stirring blade is added to a two-stage blade base stirring device, the diameter of the stirring blade between the added stirring blade and the lowermost stirring blade is in the range of 100 to 50% of the diameter of the added stirring blade or the diameter of the lowermost stirring blade, and is the same as or smaller. The design method of the platelet manufacturing apparatus according to claim 1, characterized by being.

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