Compressible bioreactor vessel having a gas outlet containing a flow restrictor and method for mixing a cell suspension therein - Patent Application 20070122997

Abstract

A bioreactor is described that includes a compressible bioreactor vessel configured to hold a cell suspension within an interior volume of the compressible bioreactor vessel, the compressible bioreactor vessel comprising a gas outlet in fluid communication with the interior volume of the compressible bioreactor vessel and configured, in use, to allow the outflow of gas from the interior volume of the compressible bioreactor vessel, the gas outlet comprising a flow restrictor configured such that the flow restrictor restricts the outflow of gas from the gas outlet when the compressible bioreactor vessel is compressed, in use.

Description

[Technical Field]

[0001] The present invention relates to a bioreactor having a compressible bioreactor container, and in particular to a bioreactor having a compressible bioreactor container equipped with a flow restrictor for restricting gas flow out of an outlet of the bioreactor container. [Background technology]

[0002] Biological processing processes, such as cell and gene therapy (CGT) manufacturing processes, are often complex and involve manual steps across several devices. The equipment systems used in various steps, or unit operations, of cell-based therapeutic product (CTP) manufacturing can include devices for various unit operations. Unit operations can include, for example, cell collection, cell isolation, selection, cell expansion, cell washing, volume reduction, cell storage, or transport. Unit operations can vary greatly based on the manufacturing model (i.e., autologous vs. allogeneic), cell type, and intended purpose, among other factors. Additionally, cells are "living" entities and are susceptible to even the simplest manipulations (e.g., differences in cell transfer procedures). The role of cell manufacturing equipment to ensure scalability and reproducibility is a critical factor for cell and gene therapy manufacturing.

[0003] Additionally, cell-based therapeutic products (CTPs) are gaining significant momentum, requiring improved cell manufacturing equipment for various cell manufacturing procedures such as, but not limited to, stem cell enrichment, chimeric antigen receptor (CAR) T-cell generation, and various cell manufacturing processes such as collection, purification, genetic modification, incubation / harvesting, washing, patient infusion, and / or freezing.

[0004] Cultivating or processing cells typically requires the use of a device to maintain the cells in a suitable culture medium, for example, when culturing the cells. Known devices include shaker flasks, roller bottles, T-flasks, and bags. While widely used, such bottles or flasks suffer from several drawbacks. During cell culture, additional medium may be added to the container, and some fluid, such as waste liquid, may be extracted from the container. Summary of the Invention [Problem to be solved by the invention]

[0005] According to one aspect of the present disclosure, there is provided a bioreactor comprising a compressible bioreactor vessel configured to hold a cell suspension within an interior volume of the compressible bioreactor vessel, the compressible bioreactor vessel comprising a gas outlet in fluid communication with the interior volume of the compressible bioreactor vessel and configured, in use, to allow the flow of gas out of the interior volume of the compressible bioreactor vessel, the gas outlet comprising a flow restrictor configured such that the flow restrictor restricts the flow of gas out of the gas outlet when the compressible bioreactor vessel is compressed, in use.

[0006] The flow restrictor restricts the flow of gas exiting the gas outlet to reduce the flow rate of gas exiting the bioreactor during compression. This allows pressure to build up within the bioreactor, allowing the compressible bioreactor vessel to expand to compensate for the pressure increase. The reduced flow rate from the bioreactor also minimizes the loss of water vapor exiting the bioreactor vessel through the outlet. Retaining water vapor (and other gaseous components) within the bioreactor vessel is beneficial for maintaining an optimal internal environment for cell growth, and the flow restrictor improves this during compression of the bioreactor vessel. [Means for solving the problem]

[0007] In these examples, the bioreactor may further include an expandable expansion vessel having an interior volume fluidly connected to the interior volume of the compressible bioreactor vessel. In this manner, when the compressible bioreactor vessel is compressed in use, gas in the interior volume of the compressible bioreactor vessel is displaced into the interior volume of the expansion vessel. This increases gas pressure in the expansion vessel, and the expansion vessel expands to compensate for this increase in gas pressure. The expansion vessel allows the compressible bioreactor vessel to expand and contract without significantly changing the pressure within the compressible bioreactor vessel. This is due to the transfer of gas between the compressible bioreactor vessel and the expansion vessel as the compressible bioreactor vessel is compressed and expanded.

[0008] In an example, the expansion vessel may include a gas outlet. Thus, as pressure in the expansion vessel increases, gas flows out of the expansion vessel through the gas outlet. A flow restrictor limits the flow of gas through the gas outlet. The restricted flow of gas from the gas outlet allows pressure in the expansion vessel to increase, and the expansion vessel expands to compensate for this increase in gas pressure. Thus, less gas is discharged through the gas outlet, and the expansion vessel accommodates more gas due to expansion under pressure.

[0009] The gas held in the expansion vessel can be returned to the bioreactor vessel, for example, after compression is reversed.

[0010] In an example, the compressible bioreactor vessel may include a base section, a top section, and a compressible sidewall extending between the base and top sections. Thus, the compressible bioreactor vessel can expand and contract to compensate for pressure therein. The compressible bioreactor vessel can be actuated to expand and contract, thereby controlling the internal volume of the compressible bioreactor vessel or agitating or mixing a cell suspension contained in the internal volume of the compressible bioreactor vessel.

[0011] In an example, the expansion vessel can be connected to the top section of a compressible bioreactor vessel, so that expansion of the expandable vessel is not limited by an exterior surface.

[0012] In an example, the top section of the compressible bioreactor vessel can include an interface plate having an opening, and the expansion vessel can be attached to the interface plate at the opening such that the interior volume of the expansion vessel is fluidly connected to the interior volume of the compressible bioreactor vessel through the opening in the interface plate.

[0013] In an example, the expansion vessel may include a base section, a top section, and a compressible sidewall extending between the base and top sections. The base section may be attached to an interface plate. Thus, the expansion vessel can expand and contract to compensate for pressure therein. The expansion vessel may also be actuated to expand and contract to control the volume of the expansion vessel.

[0014] In examples, the compressible bioreactor vessel and / or expansion vessel may be generally cylindrical if the sidewall is generally cylindrical. The bioreactor interface plate may be generally circular and planar.

[0015] In examples, the sidewall of the compressible bioreactor vessel and / or expansion vessel may be a bellows wall. The sidewall may include a plurality of inward and outward folds alternating with leaf segments. The leaf segments may be rigid. The inward and outward folds allow the leaf segments to fold against each other, thereby compressing the sidewall or, conversely, expanding the sidewall.

[0016] In examples, the bioreactor vessel may further include one or more ports for introducing and / or removing materials into and / or from the internal volume of the compressible bioreactor vessel. In examples, the one or more ports may be provided in an interface plate. The one or more ports may include a seal, e.g., a septum seal. Thus, materials may be introduced into or extracted from the internal volume of the compressible bioreactor vessel through the port. The seal covers and seals the port, preventing the introduction of contaminants into the internal volume of the compressible bioreactor vessel and maintaining a sterile environment within the internal volume.

[0017] In examples, the flow restrictor includes a valve. In some examples, the valve may allow gas to flow into and / or out of the gas outlet when the gas differential pressure at the gas outlet is at or above a threshold differential pressure. Thus, gas is prevented from flowing out of the gas outlet when the gas differential pressure at the gas outlet is below the threshold differential pressure, thereby preventing water vapor loss from the bioreactor vessel through the outlet. Furthermore, gas is allowed to flow into and / or out of the gas outlet when the gas differential pressure at the gas outlet is at or above the threshold differential pressure. This advantageously prevents substantial fluctuations in pressure within the bioreactor vessel during expansion and compression of the bioreactor vessel and reduces the force required to expand and compress the bioreactor vessel.

[0018] In examples, the valve may not restrict the flow of gas therethrough when the gas differential pressure at the gas outlet is at or above the threshold differential pressure, thus reducing the force required to expand and / or compress the bioreactor vessel.

[0019] In examples, the valve may be a two-way valve. In some examples, the valve may include a combination of an umbrella valve and a duckbill valve. In other examples, the valve may be a ball valve, particularly a two-way ball valve. In other examples, the valve may be an elastic constriction valve. In other examples, the valve may be a membrane valve having a membrane with one or more slits.

[0020] Thus, gas flow is allowed in and out of the gas outlet during expansion and compression of the bioreactor vessel, thereby compensating for changes in pressure within the bioreactor vessel due to changes in volume during expansion and compression.

[0021] In an example, the flow restrictor may include a flow-restricting path having a restricted diameter, which thus reduces the flow rate of gas through the gas outlet, and thus the pressure within the bioreactor vessel increases as the bioreactor vessel compresses, causing the bioreactor vessel to expand.

[0022] In examples, the limiting diameter can be between about 0.15 mm and about 1.5 mm. The limiting diameter can be between about 0.5 mm and about 1.0 mm. The limiting diameter can be any one of about 0.5 mm, about 0.75 mm, or about 1.0 mm.

[0023] In examples, the gas outlet may have an outlet diameter and the restriction diameter may be smaller than the outlet diameter, and thus the diameter of the gas outlet is modified to provide the restriction diameter through which gas can flow through the gas outlet.

[0024] In examples, the flow restrictor may comprise a porous structure configured to restrict gas flow out of the outlet. The porous structure may be a sintered material. The porous structure may be a filter. The porous structure may restrict the flow of gas therethrough to reduce the flow rate of gas through the outlet.

[0025] In examples, the flow restrictor may be disposed within the gas outlet. The flow restrictor may be press-fit into the gas outlet. In some examples, the flow restrictor may be disposed on the gas outlet. The flow restrictor may be press-fit onto an outer surface of the gas outlet. In other examples, the flow restrictor may be integrally formed with the gas outlet.

[0026] In examples, the flow restrictor may be integrally formed with the gas outlet.

[0027] In an example, the flow restrictor may include a tube fluidly connected to the gas outlet such that as gas exits the gas outlet and flows into the tube, the pressure at the gas outlet increases, thereby restricting the flow of gas out of the gas outlet.

[0028] In examples, the inner diameter of the tube can be between about 0.2 mm and about 1 mm. The inner diameter of the tube can be about 0.5 mm.

[0029] In examples, the length of the tube can be at least about 100 mm. The length of the tube can be between about 100 mm and about 700 mm. The length of the tube can be between about 300 mm and about 500 mm. The length of the tube can be one of about 300 mm or about 500 mm.

[0030] In an example, the flow restrictor may comprise a user-actuable valve, the actuation of which may not depend on a gas pressure differential developed across the valve.

[0031] The user-actuable valve may include a spring element operably coupled to a movable plate, which may be operable to translate to selectively block the inlet or outlet of the valve.

[0032] The spring element can be configured to bias the movable plate toward either the closed or open position, and the spring element can have a restoring force selected so that differential pressure fluctuations during use of the bioreactor do not inadvertently cause the movable plate to switch between the closed and open positions.

[0033] The user-actuable valve may also include a valve actuator configured to switch the movable plate from a closed position to an open position and / or vice versa.

[0034] The valve actuator may include a control arm operably connected to the controller. In alternative examples, the user-actuable valve may be actuated by any other suitable valve actuator. For example, the user-actuable valve may form a twist valve, an electrically actuated valve (e.g., a solenoid valve), or a magnetically actuated valve.

[0035] The user-actuable valve may be configured such that switching between the open and closed positions is independent of a pressure differential across the valve.

[0036] The user-actuable valve may be in a closed position during a compression mixing operation. The user-actuable valve may be in an open position during a breathing operation to allow maximum air exchange with the contents of the bioreactor vessel and / or expansion vessel.

[0037] The controller may be configured to operate the valve according to a predefined sequence of operating modes.

[0038] In an example, the bioreactor may further include a filter disposed in the gas flow path between the internal volume of the compressible bioreactor vessel and the gas outlet and / or flow restrictor. The filter may be disposed in the gas outlet. The filter may include a hollow body providing a flow path therethrough and a filter element extending across the flow path. The hollow body may be wider at a central portion of the hollow body, and the filter element may be disposed within the central portion. The hollow body may have end portions extending from each end of the central portion. One or both of the end portions may include a flow restrictor. Each end portion may be shaped as a spigot. The filter element may be a polyethersulfone membrane or a polyvinylidene fluoride membrane. Thus, the filter can remove contaminants from the gas flowing therethrough. This prevents contaminants in the surrounding environment from reaching the cell suspension within the internal volume of the compressible bioreactor vessel, thereby preventing contamination of the cell suspension.

[0039] According to a further aspect of the present disclosure, a filter is provided for a gas outlet of a bioreactor. The filter may include a hollow body providing a flow path. The hollow body has a central portion and end portions extending from the central portion. The central portion is wider than the end portions. A filter element is arranged within the central portion to extend across the flow path. The end portions have a reduced diameter to restrict airflow through the flow path.

[0040] In this way, the filter can be used at the gas outlet of a bioreactor vessel, reducing the diameter of the end portion to restrict gas flow out of the gas outlet and reduce the flow rate through the filter.

[0041] In examples, the end portion may be a first end portion, and the filter may include a second end portion extending from an opposite side of the central portion to the first end portion.

[0042] In examples, a flow restrictor may be provided at the first end portion and / or the second end portion to reduce the diameter and restrict air flow through the flow passage.

[0043] In examples, the flow restrictor may be press-fit into the first end portion and / or the second end portion. In other examples, the flow restrictor may be integrally formed with the first end portion and / or the second end portion.

[0044] In examples, the flow restrictor may be integrally formed with the first end portion and / or the second end portion.

[0045] In examples, the first end portion and / or the second end portion may be formed as a spigot.

[0046] In examples, the filter element may be a polyethersulfone membrane or a polyvinylidene fluoride membrane.

[0047] According to a further aspect of the present disclosure, there is provided a method of mixing a cell suspension in a bioreactor, in an example, the method being a method of mixing a cell suspension using the bioreactor vessel described above.

[0048] The method includes providing a bioreactor comprising a compressible bioreactor vessel having a gas outlet including a flow restrictor, introducing a cell suspension into an interior volume of the compressible bioreactor vessel, compressing the compressible bioreactor vessel to reduce the interior volume of the compressible bioreactor vessel, and restricting gas flow through the gas outlet with the flow restrictor while compressing the compressible bioreactor vessel.

[0049] In examples, the compressible bioreactor vessel can include an expansion vessel having an interior volume fluidly connected to the interior volume of the compressible bioreactor vessel. The method can include transferring gas from the interior volume of the compressible bioreactor vessel to the interior volume of the expansion vessel upon compression of the compressible bioreactor vessel.

[0050] In an example, the flow restrictor may include a valve. Restricting gas flow through the gas outlet with the flow restrictor may include blocking gas flow through the valve when the gas differential pressure at the gas outlet is below a threshold differential pressure, and allowing gas to flow through the valve when the gas differential pressure at the gas outlet is at or above the threshold differential pressure.

[0051] Examples of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0052] [Figure 1A] FIG. 1 illustrates a bioreactor. [Figure 1B] FIG. 1 illustrates a bioreactor. [Figure 2] FIG. 2 is a cross-sectional view illustrating the bioreactor of FIG. 1. [Figure 3] FIG. 2 is a cross-sectional perspective view illustrating the bioreactor of FIG. 1. [Figure 4] FIG. 2 is a cross-sectional view illustrating the outlet of the bioreactor of FIG. 1 with a first example of a flow restrictor. [Figure 5(a)] 5A and 5B are diagrams illustrating arrangements of the flow restrictors of FIG. 4. [Figure 5(b)] 5A and 5B are diagrams illustrating arrangements of the flow restrictors of FIG. 4. [Figure 6] FIG. 10 illustrates a second example of a flow restrictor. [Figure 7(a)] FIG. 2 illustrates the outlet of the bioreactor of FIG. 1 with a third example of a flow restrictor. [Figure 7(b)] FIG. 2 illustrates the outlet of the bioreactor of FIG. 1 with a third example of a flow restrictor. [Figure 8(a)] FIG. 10 illustrates a fourth example of a flow restrictor. [Figure 8(b)] FIG. 10 illustrates a fourth example of a flow restrictor. [Figure 8(c)] FIG. 10 illustrates a fourth example of a flow restrictor. [Figure 8(d)] FIG. 10 illustrates a fourth example of a flow restrictor. [Figure 9(a)] FIG. 10 illustrates a fifth example of a flow restrictor. [Figure 9(b)] FIG. 10 illustrates a fifth example of a flow restrictor. [Figure 10(a)] FIG. 10 illustrates a sixth example of a flow restrictor. [Figure 10(b)] FIG. 10 illustrates a sixth example of a flow restrictor. [Figure 10(c)] FIG. 10 illustrates a sixth example of a flow restrictor. [Figure 11(a)] FIG. 10 illustrates a seventh example of a flow restrictor. [Figure 11(b)] FIG. 10 illustrates a seventh example of a flow restrictor. [Figure 12] 1 is a graph illustrating the load required to compress a bioreactor vessel with different flow restrictors. DETAILED DESCRIPTION OF THE INVENTION

[0053] The exemplary embodiments described relate to assemblies for handling biological materials. In particular, some embodiments relate to assemblies that are aseptic or sterilized. It should be noted that the terms "sterile" and "sterilized" may be used interchangeably throughout this disclosure. References to fluids in the detailed description are not intended to limit the scope of protection to such materials. As one skilled in the art will understand, fluids as described herein are merely examples of suitable materials for use with assemblies as described. Similarly, references may be made to vessels, containers, or the like, but such references are not intended to limit the scope of protection to such vessels or containers. As one skilled in the art will understand, vessels, containers, and the like are described herein by way of example only.

[0054] Certain terminology is used in the following description for convenience only and not as a limitation. The terms "upper" and "lower" designate directions in the referenced drawings and relate to the described components when assembled and mounted. The terms "inner," "inwardly," and "outer," and "outwardly" refer to directions toward and away from, respectively, a designated centerline or geometric center (e.g., central axis) of the described element, with the particular meaning being readily apparent from the context herein. Additionally, the terms "proximal" (i.e., closer) and "distal" (i.e., farther) designate positions relative to an axis or attachment point.

[0055] Furthermore, as used herein, the terms "connected," "attached," "coupled," and similar expressions are intended to include a direct connection between two members with no other intervening members, as well as an indirect connection between members where one or more other members are interposed between them. The term specifically includes the words set forth above, derivatives thereof, and words of similar import.

[0056] Furthermore, unless otherwise specified, the use of ordinal numbers such as "first," "second," "third," etc., merely indicates that different instances of similar objects are being referred to and is not intended to imply that the objects so described must be in any given order, whether temporal, spatial, ordinal, or in any other manner. Like reference numerals are used throughout to denote like features.

[0057] 1A, 1B, and 2 show a bioreactor 10 of the present invention. The bioreactor 10 includes a compressible bioreactor vessel 12, an interface plate 13, and an expansion vessel 14, alternatively referred to as a breathing vessel.

[0058] During use, the compressible bioreactor vessel 12 has an internal volume that holds a fluid in which cell processing occurs. In particular, the fluid is a cell suspension, comprising a population of cells present in a liquid medium. In various examples, the population of cells provided to the compressible bioreactor vessel 12 during use can include any human or animal cell type, such as any type of adult stem or primary cell, T cells, CAR-T cells, monocytes, leukocytes, erythrocytes, NK cells, γδ T cells, tumor-infiltrating T cells, mesenchymal stem cells, embryonic stem cells, induced pluripotent stem cells, adipose-derived stem cells, Chinese hamster ovary cells, NSO mouse myeloma, HELA cells, fibroblasts, HEK cells, insect cells, or organoids. Preferably, the population of cells can include T cells. Alternatively, the population of cells can include any microbial cell type, such as bacteria, fungi, archaea, protozoa, or algae cells.

[0059] The compressible bioreactor vessel 12 and the expansion vessel 14 are compressible, for example, by having bellows walls. The compressible bioreactor vessel 12 can expand and contract when filled and emptied. The expansion vessel 14 can expand and contract when gas is transferred from the compressible bioreactor vessel 12 into and out of the expansion vessel 14.

[0060] As shown in FIGS. 1A, 1B, and 2, compressible bioreactor vessel 12 has a base section with bottom wall 15, a top section with interface plate 13, and compressible sidewall 16. Bottom wall 15 is disposed opposite interface plate 13. Bottom wall 15 is rigid or attached to a rigid plate to provide the bottom surface of compressible bioreactor vessel 12. Top portion 17 of compressible sidewall 16 is attached to interface plate 13, as shown in FIG. 2. Top portion 17 may include a rigid ring or the like for attachment to interface plate 13. Compressible sidewall 16 is compressible such that bottom wall 15 can move toward and away from interface plate 13 to change the interior volume of compressible bioreactor vessel 12.

[0061] The compressible sidewall 16 may be a bellows wall having a concertina-like arrangement that allows the compressible sidewall 16 to fold for compression. In particular, the compressible sidewall 16 may include a series of alternating inward folds 16a and outward folds 16b that allow the compressible sidewall 16 to compress like a bellows or concertina. Rigid leaf portions extend between the inward folds 16a and outward folds 16b. The inward folds 16a and outward folds 16b may be formed by thinned sections in the compressible sidewall 16, with the inward folds 16a having a thinned section arranged on the outer surface of the compressible sidewall 16 and the outward folds 16b having a thinned section arranged on the inner surface of the compressible sidewall 16.

[0062] The compressible bioreactor vessel 12 can therefore expand and contract, or be expanded and contracted, according to the material held in the compressible bioreactor vessel 12. In particular, the compressible bioreactor vessel 12 can expand as the cell culture within the compressible bioreactor vessel 12 grows and / or as additional material is added. The compressible bioreactor vessel 12 can be contracted and expanded by an actuator (not shown) adapted to move, e.g., push and / or pull, the bottom wall 15 and / or interface plate 13 of the compressible bioreactor vessel 12 to change the volume of the compressible bioreactor vessel 12.

[0063] 2 and 3, interface plate 13 has a lower surface that is sealably connected to the top 17 of the compressible side wall 16 of compressible bioreactor vessel 12. Interface plate 13 also has an upper surface that is sealably connected to the lower portion 20 of the compressible side wall 18 of expansion vessel 14.

[0064] The interface plate 13 has one or more ports 22 for the transfer of materials into and out of the interior volume of the compressible bioreactor vessel 12. External components can be connected to one or more of the ports 22 to introduce materials through the ports 22. Each of the ports includes a seal 23, e.g., a septum seal, that maintains a sealed environment within the interior volume of the compressible bioreactor vessel 12 and allows a needle to pass through to form a fluid connection within the interior volume of the compressible bioreactor vessel 12. In an alternative example, each port 22 may have a valve, cap, or other closure that provides an openable or rupturable seal. One or more of the ports 22 may have a dip tube 24 that extends from the port 22 into the interior volume of the compressible bioreactor vessel 12. The dip tube 24 can penetrate into a cell suspension during use to be used to remove materials, e.g., a sample, from the compressible bioreactor vessel 12.

[0065] The baffle 31 is attached to the interface plate 13 such that the baffle 31 is suspended within the interior volume of the compressible bioreactor vessel 12. The baffle 31 may be attachable to the interface plate 13 by a threaded connector, or by a clip or clamp. The baffle 31 is attached to the center of the interface plate 13 such that the baffle 31 is centered within the compressible bioreactor vessel 12. However, it will be understood that the baffle 31 may be positioned off-center within the compressible bioreactor vessel 12. The bottom surface of the baffle 31 is substantially flat and faces the bottom wall 15 of the compressible bioreactor vessel 12. The baffle 31 also has a conical upper surface that faces the interface plate 13. The baffle 31 is circular and sized to space it from the compressible side wall 16 of the compressible bioreactor vessel 12. This allows the dip tube 24 to pass between the compressible side wall 16 and the baffle 31 to provide a fluid sampling path from the compressible bioreactor vessel 12 to the interface plate 13 .

[0066] The baffles 31 are provided to mix the cell suspension contained in the interior volume of the compressible bioreactor vessel 12 during use. In particular, the bottom wall 15 of the compressible bioreactor vessel 12 can be moved relative to the interface plate 13 and the baffles 31 such that the baffles 31 contact and mix the cell suspension within the interior volume of the compressible bioreactor vessel 12. In examples, the base wall 15 can be raised or lowered relative to the interface plate 13 (i.e., changing the distance between the base 15 and the interface plate 13), and / or the base 15 can be tilted relative to the interface plate 13, and / or the base 15 can be rotated relative to the interface plate 13.

[0067] Interface plate 13 has an opening 21 extending between its upper and lower surfaces to permit gas flow between the interior volumes of compressible bioreactor vessel 12 and expansion vessel 14. Opening 21 may include a filter. The filter may prevent particulates, such as cells, from migrating from compressible bioreactor vessel 12 to expansion vessel 14. The filter may additionally prevent liquid from migrating from compressible bioreactor vessel 12 to expansion vessel 14.

[0068] As shown in FIG. 3 , the interface plate 13 has a hollow ring-shaped protrusion 34 extending from the upper side of the interface plate 13. The outer surface of the ring-shaped protrusion 34 connects to the lower side 20 of the compressible sidewall 18 of the expansion vessel 14. The inner surface of the ring-shaped protrusion 34 has a plurality of openings 21 spaced about the inner surface. The openings 21 allow fluid communication between the compressible bioreactor vessel 12 and the expansion vessel 14. A plurality of walls 35 extend inward from the inner surface of the ring-shaped protrusion 34 toward the center of the interface plate 13. The walls 35 are positioned approximately at the center of each opening 21. The walls 35 create a tortuous (non-linear) path for the gas as it flows between the compressible bioreactor vessel 12 and the expansion vessel 14, thereby increasing the surface area that the gas contacts as it flows into the expansion vessel 14. As the gas contacts surfaces around openings 21, including walls 35, water vapor in the gas condenses on these surfaces. The upper surface of interface plate 13 within the inner surface of ring-shaped protrusion 34 is sloped toward openings 21 to direct liquid droplets back through openings 21 and return liquid to the interior volume of the compressible bioreactor vessel. Thus, the increased surface area created by walls 35 around openings 21 reduces the passage of liquid vapor out of compressible bioreactor vessel 12 while providing an opening through which gas can freely flow between compressible bioreactor vessel 12 and expansion vessel 14.

[0069] The expansion vessel 14 has a bottom section formed by the interface plate 13 , a top section 25 connected to a filter 19 having a gas outlet 26 , and a compressible sidewall 18 .

[0070] A lower portion 20 of the compressible side wall 18 is attached to the interface plate 13. The lower portion 20 may comprise a rigid ring or the like for attachment to the interface plate 13. The compressible side wall 18 is compressible such that the top section 25 can move toward and away from the interface plate 13 to change the interior volume of the expansion vessel 14.

[0071] The compressible sidewall 18 may be a bellows wall having a concertina-like arrangement that allows the compressible sidewall 18 to fold for compression. In particular, the compressible sidewall 18 may include a series of alternating inward folds 18a and outward folds 18b that allow the compressible sidewall 18 to compress like a bellows or concertina. Rigid leaf portions extend between the inward folds 18a and outward folds 18b. The inward folds 18a and outward folds 18b may be formed by thinned sections in the compressible sidewall 18, with the inward folds 18a having a thinned section arranged on the outer surface of the compressible sidewall 18 and the outward folds 18b having a thinned section arranged on the inner surface of the compressible sidewall 18.

[0072] The expansion vessel 14 allows the compressible bioreactor vessel 12 to expand and contract without significantly changing the pressure within the compressible bioreactor vessel 12. Alternatively or additionally, the expansion vessel 14 may be operable, for example, by being mechanically or manually compressed or expanded, to expand or retract the compressible sidewall 18 of the expansion vessel 14, thereby changing the volume of the compressible bioreactor vessel 12. Alternatively or additionally, the expansion vessel 14 may be operable, for example, by being mechanically or manually compressed or expanded, to change the pressure within the compressible bioreactor vessel 12.

[0073] 1A and 1B, a cage 29 is disposed around the expansion vessel 14 and keeps the expansion vessel 14 aligned as it expands and contracts. The cage 29 includes a first cage portion 29a attached to the interface plate 13 and a second cage portion 29b slidably attached to the first cage portion 29a. The second cage portion 29b can slide in the direction of expansion and contraction of the expansion vessel 14. A block prevents the second cage portion 29b from disengaging from the first cage portion 29a.

[0074] Thus, the expansion vessel 14 can expand or contract depending on the operational and environmental characteristics of the bioreactor 10. As the expansion vessel 14 expands and contracts, the cage 29 constrains movement of the expansion vessel 14 as the first and second cage sections 29a, 29b slide relative to one another.

[0075] The cage 29 includes a clamping feature 30, in this example a lip, that can be grasped by an actuator. In other examples where the bioreactor 10 does not include an expansion vessel 14, the lip 30 can be provided on the interface plate 13.

[0076] In some examples, locking elements may be provided on first cage portion 29a and / or second cage portion 29b to lock second cage portion 29b in a first retracted position (see FIG. 1A) and / or a second expanded position (see FIG. 1B) relative to first cage portion 29a. The locking elements may be any suitable locking elements, such as corresponding notches and protrusions. In other examples, second cage portion 29b may be held in the first retracted position and / or the second expanded position by an actuator.

[0077] As shown in FIGS. 2, 4, and 7(a), the filter 19 has a hollow body that provides a flow path therethrough. This flow path is the gas outlet 26 of the bioreactor 10. The hollow body has a central portion 32, a first end 27 extending from a first side of the central portion 32, and a second end 28 extending from a second side of the central portion 32. The central portion 32 is wider than the first and second ends 27, 28 to accommodate a filter element 33 therein. The filter element 33 extends across the flow path so that all gas flow through the flow path passes through the filter element 33. Any suitable filter element 33 that filters particulates, such as microorganisms or other contaminants, can be used. For example, the filter element 33 can be a polyethersulfone membrane or a polyvinylidene fluoride membrane. The first end 27 of the filter is positioned within the interior volume of the expansion vessel 14, and the second end 28 of the filter is positioned outside the expansion vessel 14. In some examples, the filter 19 may not include the second end 28 as illustrated.

[0078] Outlet 26 allows gas exchange between the internal volume of expansion vessel 14 and an external environment, such as a bioreactor housing. In particular, as the pressure in the internal volume of expansion vessel 14 increases, gas flows out of expansion vessel 14 through outlet 26. The pressure in expansion vessel 14 may increase as a result of contraction of expansion vessel 14 and / or contraction of compressible bioreactor vessel 12 forcing gas from the expansion vessel 14 into the expansion vessel 14. Additionally, as the pressure in the internal volume of expansion vessel 14 and / or compressible bioreactor vessel 12 decreases, gas flows into expansion vessel 14 through outlet 26. The pressure in expansion vessel 14 may decrease as a result of expansion of expansion vessel 14 and / or expansion of compressible bioreactor vessel 12 drawing gas from the expansion vessel 14 into the compressible bioreactor vessel 12.

[0079] In some embodiments, outlet 26 may include a one-way valve that only allows gas to flow out of bioreactor 10. The gas inlet may be provided in one of compressible bioreactor vessel 12, interface plate 13, or expansion vessel 14. The gas inlet may include a one-way valve that only allows gas to flow into bioreactor 10.

[0080] FIG. 4 shows a first example of a flow restrictor. The flow restrictor 40 is positioned within the second end 28 of the outlet 26. The flow restrictor 40 restricts the flow of gas through the outlet 26. This slows the rate at which gas exits the internal volume of the expansion vessel 14, thereby reducing the volume of gas that exits the internal volume of the expansion vessel 14 upon compression and reducing the loss of liquid in the form of vapor from the bioreactor 10. When the flow of gas through the outlet 26 is restricted, this allows the pressure in the internal volume of the expansion vessel 14 to increase. When the pressure within the expansion vessel reaches a certain level, the expansion vessel 14 expands and accepts additional gas from the compressible bioreactor vessel 12.

[0081] 5(a) and 5(b) show examples of the flow restrictor of FIG. 4. As shown in FIGS. 5(a) and 5(b), the flow restrictor 40 has a body portion having a first end 41 and a second end 42. The body portion is hollow to provide a gas flow path extending from the first end 41 to the second end 42. The inner diameter (A) of the hollow body is smaller than the diameter (B) of the outlet 26 (see FIG. 2). For example, the diameter (B) of the outlet 26 may be between about 3 mm and about 5 mm, e.g., about 3.8 mm, and the inner diameter (A) of the hollow body may be between about 0.15 mm and about 1.5 mm, e.g., about 0.5 mm, about 0.75 mm, or about 1 mm. The flow restrictor 40 thereby restricts the diameter (B) of the outlet 26, thereby restricting gas outflow from the outlet. At the first end 41 of the body, the outer diameter of the body is the same as or smaller than the diameter (B) of the outlet 26. This allows the first end 41 of the flow restrictor 40 to be inserted into the second end 28 of the outlet 26.

[0082] In some examples, as illustrated in FIGS. 5(a) and 5(b), the first end 41 of the flow restrictor 40 is inserted into the second end 28 of the outlet 26. The second end 42 of the body has a flange. The flange contacts the outer edge of the second end 28 of the outlet 26. The flange can act as a stopper to prevent the flow restrictor 40 from moving through the outlet 26. In one example, as shown in FIG. 4, the first end 41 of the flow restrictor 40 is press-fit into the second end 28 of the outlet 26. In another example, as shown in FIGS. 5(a) and 5(b), the first end 41 includes an O-ring 43 to provide a seal between the first end 41 of the flow restrictor 40 and the outlet 26. In another example, the flow restrictor can be integrally formed with the second end 28 of the outlet 26.

[0083] The inner diameter (A) of the hollow body can be between about 0.15 mm and about 1.5 mm. In some examples, the inner diameter (A) of the hollow body is between about 0.5 mm and about 1.0 mm. In some examples, the inner diameter (A) of the hollow body is about 0.50 mm, or about 0.75 mm, or about 1.00 mm.

[0084] As shown in Figures 5(a) and 5(b), the second end 42 of the flow restrictor 40 may have different lengths. The length of the second end 42 of the flow restrictor 40 shown in Figure 5(a) is longer than the length of the second end 42 of the flow restrictor 40 shown in Figure 5(b). In examples, the length of the second end 42 of the flow restrictor 40 may be between about 1 mm and about 15 mm. In examples, the length of the second end 42 of the flow restrictor 40 may be between about 1 mm and about 10 mm. In examples, the length of the second end 42 of the flow restrictor 40 is about 1.5 mm. In examples, the length of the second end 42 of the flow restrictor 40 is about 10 mm. It will be appreciated that the longer the length of the second end 42 of the flow restrictor 40, the more restricted the flow rate will be.

[0085] The flow restrictor 40 may be formed from any suitable filter material. The flow restrictor 40 may be formed from a gamma radiation resistant polymer. For example, the flow restrictor 40 may be formed from a polymer such as a polyaryletherketone, e.g., polyetheretherketone (PEEK). The flow restrictor 40 may be manufactured by machining (turning). Additionally or alternatively, the flow restrictor 40 may be manufactured by an additive process or molding.

[0086] 6 shows a second example of a flow restrictor 50. The flow restrictor 50 is positioned at the second end 28 of the outlet 26 in the same manner as the flow restrictor 40 shown in FIG.

[0087] The flow restrictor 50 has a body having a first end 51 and a second end 52. The first end 51 of the body is hollow to allow gas to enter the flow restrictor 50. The second end 52 of the body comprises a porous material. In some examples, the second end 52 of the body may be formed from a porous material. In other examples, the flow restrictor 50 is the same as the flow restrictor described with reference to Figures 4 through 5(b), except that the second end 52 of the body is covered with a porous material.

[0088] The porous material allows a restricted gas flow therethrough, which restricts gas escape from outlet 26.

[0089] The body of the flow restrictor 50 may be formed from any suitable filter material. The body of the flow restrictor 50 may be formed from a gamma radiation resistant polymer. For example, the body of the flow restrictor 50 may be formed from a polymer such as a polyaryletherketone, e.g., polyetheretherketone (PEEK). The body of the flow restrictor 50 may be manufactured by machining (turning). Additionally or alternatively, the body of the flow restrictor 50 may be manufactured by an additive process or molding. The porous structure may be a sintered polymer. Any suitable polymer may be used, such as polytetrafluoroethylene (PTFE), polyethylene (PE), or polypropylene (PP).

[0090] 7(a) and (b) illustrate a third example of a flow restrictor 60. The flow restrictor 60 includes an elongated tube 61. A first end portion 62 of the elongated tube 61 is positioned in fluid communication with the second end 28 of the outlet 26. The elongated tube 61 provides increased resistance to gas exiting the outlet 26, thereby restricting gas flow through the outlet.

[0091] The elongated tube 61 is secured in fluid communication with the outlet 26 by a tube support 63. The tube support 63 surrounds the second end 28 of the outlet 26 and the first end portion 62 of the elongated tube 61, maintaining the first end portion 62 of the elongated tube 61 and the second end 28 of the outlet 26 in alignment and allowing fluid to flow therebetween.

[0092] The thin tube 61 has an inner diameter that is smaller than the diameter (B) of the outlet 26. The inner diameter of the thin tube 61 may be from 0.25 mm to 1 mm. In some examples, the inner diameter of the thin tube 61 is 0.5 mm.

[0093] The length of the elongated tube 61 is between 100 mm and 700 mm. In some examples, the length of the elongated tube 61 is between 300 mm and 500 mm. In some examples, the length of the elongated tube 61 is 300 mm or 500 mm.

[0094] The elongated tube 63 has a bent portion 65 adjacent the tube support 63. The bent portion 65 may be formed from a relatively stiff material compared to the material of the remainder of the tube, or the bent portion 65 may be reinforced to prevent the bent portion 65 from kinking and blocking gas flow.

[0095] As shown in FIG. 7(a), second cage section 29b covers tube support 63 and at least a portion of the elongated tube, including second end portion 64 of the elongated tube.

[0096] 7(b), the elongated tube 63 may be coiled to prevent kinks in the tube that would block gas flow and to reduce the footprint of the flow restrictor 60. The tube support 63 comprises a circular base with guides for receiving the elongated tube 61 in a coiled arrangement.

[0097] According to the illustrated example, the elongated tube 61 remains fixed to the second end 28 of the outlet 26 by a tube support 63. In other examples, the first end portion 62 of the elongated tube 61 may be press-fit into the second end 28 of the outlet 26 or sealed to the second end 28 of the outlet 26 by an O-ring such that the second end 28 maintains fluid communication between the first end portion 62 of the elongated tube 61 and the outlet 26.

[0098] Figures 8(a) through 10(c) show examples of valve flow restrictors 70, 80, and 90. Figures 8(a) through 8(d) show a fourth example of a flow restrictor 70 in the form of a combination umbrella and duckbill valve. Figures 9(a) and 9(b) show a fifth example of a flow restrictor 80 in the form of an elastic clamping valve. Figures 10(a) through 10(c) show a sixth example of a flow restrictor 90 in the form of a two-way ball valve. These valves 70, 80, and 90 allow gas to flow through the valve when the gas differential pressure at the gas outlet 26 is at or above a threshold differential pressure and prevent gas flow when the gas differential pressure is below the threshold differential pressure. The valves 70, 80, and 90 remain closed when the gas differential pressure is below the threshold differential pressure, thereby preventing the loss of fluid in the form of vapor from the bioreactor vessel 12. However, the valves 70, 80, 90 open when the gas differential pressure at the gas outlet 26 is at or above a threshold differential pressure.

[0099] Valves 70, 80, 90 open when the gas differential pressure rises to a differential pressure equal to or greater than the threshold differential pressure. This results in a nearly constant increasing force profile at valves 70, 80, 90. In turn, this allows bioreactor vessel 12 to be expanded and / or contracted without significantly increasing the force required to expand or contract bioreactor vessel 12. This also prevents substantial fluctuations in pressure within bioreactor vessel 12 and / or expansion vessel 14 during expansion and / or contraction.

[0100] Other one-way or two-way pressure-activated valves (not shown) may be utilized in the present invention. The valve may be any valve that can be actuated by a gas pressure differential adjacent to the valve. For example, the valve may be a membrane valve having one or more slits therein. When the gas pressure differential rises to or above a threshold pressure differential, the membrane of the membrane valve bends toward the relatively lower gas pressure, opening one or more slits and allowing gas to flow therethrough.

[0101] As shown in Figures 8(a) through 8(d), a fourth example of a flow restrictor, a combination umbrella and duckbill valve 70, includes a valve element 71 and a support 72. As shown in Figure 8(b), the valve element 71 has an umbrella portion 73, which is a flange extending away from a first upper end of the valve element 71. The valve element 71 also has a duckbill portion 74 that includes an elastomeric lip.

[0102] The support 72 has a valve seat 77 at the upper end of the support 72. The valve seat 77 has at least one opening 75 therein to allow gas to flow therethrough. The valve seat can have multiple openings. In one example, the valve seat has four openings. The thickness of the valve seat can be selected to manipulate the gas pressure differential required to open the valve. In examples, the thickness of the valve seat is about 0.6 to 1.2 mm. In some examples, the thickness of the valve seat is about 0.6 mm, 0.8 mm, 1.0 mm, or 1.2 mm.

[0103] In the rest position, umbrella portion 73 rests against valve seat 77, blocking opening 75 in valve seat 77. In the rest position, elastomeric lips of duckbill portion 74 rest against each other, blocking air flow through central opening 76 of valve element 71.

[0104] As shown in FIG. 8(c), when the gas pressure in gas outlet 26 is greater than the external pressure and the gas differential pressure is at or above the threshold differential pressure, umbrella portion 73 lifts off support 72, allowing gas flow G to exit bioreactor vessel 12 and / or expansion vessel 14 through opening 75. out The gas pressure in the gas outlet 26 allows the bioreactor vessel 12 and / or expansion vessel 14 to com8(b) and 8(d), the umbrella portion 73 returns to its rest position, resting against the upper end of the support 72 and blocking gas flow through the opening 75. As shown in FIG. 8(d), when the gas pressure near the central opening 76 of the valve element 71 is greater than the gas pressure in the gas outlet 26, the elastomeric lips of the duckbill portion 74 move away from each other to prevent gas flow G when the gas differential pressure at the gas outlet 26 falls below the threshold differential pressure. in The gas pressure near the central opening 76 of the valve element 71 allows the bioreactor vessel 12 and / or expansion vessel 14 to flow in the direction F. exp 8(b) and 8(c), the elastomeric lips of the duckbill portion 74 return to their resting positions, resting against each other and preventing gas flow through the central opening 76. When the gas differential pressure at the gas outlet 26 drops below the threshold differential pressure, the elastomeric lips of the duckbill portion 74 return to their resting positions, resting against each other and preventing gas flow through the central opening 76, as shown in FIGS.

[0105] The support 72 is press-fit onto the outer surface of the second end 28 of the outlet 26. According to an alternative example, the support 72 may be press-fit into the second end 28 of the outlet 26. In yet another example, the support 72 may be integrally formed with the second end 28 of the outlet 26.

[0106] As shown in Figures 9(a) and 9(b), the resilient clamping valve 80 of the fifth example of the flow restrictor includes a resilient valve element 81 and a compression ring 82. The resilient valve element 81 is cylindrical and formed from a resilient material. The resilient valve element 81 is biased toward its cylindrical shape. The compression ring 82 is disposed around the outer surface of the resilient valve element 81. The compression ring 82 is formed from a resilient material. The compression ring 82 compresses a portion of the resilient valve element 81 in a rest position, thereby reducing the diameter of the resilient valve element 81 at that portion.

[0107] As shown in FIG. 9(b), when the gas differential pressure at gas outlet 26 is at or above the threshold differential pressure, compression ring 82 expands, widening the diameter of resilient valve element 81 and allowing gas flow G out 9( a ), the compression ring compresses and returns to its rest position, reducing the diameter of the resilient valve element 81 and preventing gas flow through the resilient valve element 81. The gas differential pressure at the gas outlet 26 may increase when the bioreactor vessel 12 and / or expansion vessel 14 is compressed, increasing the pressure in the bioreactor vessel 12 and / or expansion vessel 14 relative to the external pressure. The gas differential pressure at the gas outlet 26 may also increase when the bioreactor vessel 12 and / or expansion vessel 14 is expanded, decreasing the pressure in the bioreactor vessel 12 and / or expansion vessel 14 relative to the external pressure. When the gas differential pressure at the gas outlet 26 falls below a threshold differential pressure, the compression ring compresses and returns to its rest position, reducing the diameter of the resilient valve element 81 and preventing gas flow through the resilient valve element 81, as shown in FIG. 9( a ).

[0108] The resilient clamp valve 80 may be provided on the inner surface of the gas outlet 26. Alternatively, the resilient clamp valve 80 may be connected to the end of the gas outlet 26.

[0109] 10(a) through 10(c), the six example two-way ball valve 90 of the flow restrictor includes a first ball valve 91 connected to a first spring element 92, a first ball seat 93, a second ball valve 94 connected to a second spring element 95, and a second ball seat 96. The two-way ball valve 90 also has an outlet end 97 and an inlet end 98.

[0110] As shown in FIG. 10(a), each of the first and second ball valves 91, 94 rests in a rest position on a respective first and second ball seat 93, 98.

[0111] A two-way ball valve 90 may be connected to the end of the gas outlet (26, see FIG. 2). The two-way ball valve 90 may otherwise be incorporated into the gas outlet 26 by any suitable means.

[0112] As shown in FIG. 10( b ), when the gas pressure at the outlet end 97 (i.e., the gas pressure within the gas outlet 26 ) becomes greater than the gas pressure at the inlet end 98 (i.e., the external pressure) and the gas differential pressure is at or above the threshold differential pressure, the second ball valve 94 lifts away from the second ball seat 96 against the bias of the second spring element 95, allowing gas flow G out 10(a) and 10(c), second ball valve 94 is biased by second spring element 95 to rest against second ball seat, preventing gas from flowing out through valve 90 from bioreactor vessel 12 and / or expansion vessel 14. When the gas differential pressure at gas outlet 26 falls below the threshold differential pressure, second ball valve 94 is biased by second spring element 95 to rest against second ball seat, preventing gas from flowing out through valve 90, as shown in FIGS.

[0113] As shown in FIG. 10(c), when the gas pressure at the inlet end 98 (i.e., the external pressure) becomes greater than the gas pressure at the outlet end 97 (i.e., the gas pressure at the gas outlet 26) and the gas differential pressure is at or above the threshold differential pressure, the first ball valve 91 lifts away from the first ball seat 93 against the bias of the first spring element 92, allowing the gas flow G in10(a) and 10(b), when the gas differential pressure at gas outlet 26 falls below a threshold differential pressure, first ball valve 91 is biased by first spring element 92 to rest against first ball seat 93, preventing gas from flowing through valve 90.

[0114] 11(a)-11(b) show a seventh example of a flow restrictor in the form of a user-actuatable valve 100. The user-actuatable valve 100 includes an outlet end 110 and an inlet end 120.

[0115] The user-actuable valve 100 may be connected to the end of the gas outlet 26 (see FIG. 2). The user-actuated valve 100 may otherwise be incorporated into the gas outlet 26 by any suitable means.

[0116] User-actuable valve 100 includes a movable plate 101 and a spring element 102. Movable plate 101 includes a seal 103 for sealing movable plate 101 against inlet end 120, thereby preventing gas from flowing therethrough. In this example, seal 103 is an O-ring having an inner diameter that exceeds the diameter of inlet end 120. In other examples, seal 103 may be omitted. For example, movable plate 101 may include a flexible material operable to seal against the periphery of inlet end 120.

[0117] Movable plate 101 is operable to translate between a closed position and an open position upon user actuation of user-actuatable valve 100 .

[0118] 11a shows user-actuatable valve 100 with movable plate 101 in the closed position. As shown, when movable plate 101 is in the closed position, seal 103 is sandwiched between the peripheral wall of inlet end 120 and movable plate 101. Movable plate 101 is essentially impermeable to fluids, and therefore this configuration prevents gas from exiting or entering user-actuatable valve 100 through inlet end 120.

[0119] Spring element 102 is operatively connected to movable plate 101 and configured to bias movable plate 101 toward the closed position. Spring element 102 has a restoring force selected so that differential pressure fluctuations during use of bioreactor 10 do not inadvertently cause movable plate 101 to switch between the closed and open positions.

[0120] The user-actuable valve 100 also includes a valve actuator for actuating the movable plate 101 between the closed and open positions. In this example, the valve actuator includes a control arm 104 operably connected to a controller (not shown). The movable plate 101 includes a connector 105 configured to selectively interface with the control arm 104.

[0121] The controller (not shown) is a button for depressing the control arm 104 toward the movable plate 101. The valve actuator is configured such that when a user activates the button, the control arm 104 is pushed into contact with the connector 105, as indicated by block arrow 106. The force of the control arm 104 overcomes the reaction force of the spring element 102, moving the movable plate 101 away from the inlet end 120. In this manner, the valve actuator is configured to switch the movable plate 101 from a closed position to an open position.

[0122] In alternative examples, user-actuable valve 100 may be actuated by any other suitable valve actuator. For example, user-actuable valve 100 may form a twist valve, an electrically actuated valve (e.g., a solenoid valve), or a magnetically actuated valve.

[0123] 11b shows the user-actuable valve 100 when the movable plate 101 is in the open position. In this position, the inlet end 120 is fluidly connected to the outlet end 110. This configuration allows gas to flow out of or into the bioreactor vessel 12 and / or expansion vessel 14 through the user-actuable valve 100. When the movable plate 101 is in the open position, the pressure within the bioreactor vessel 12 and / or expansion vessel 14 equilibrates with respect to the external pressure at the gas outlet 26.

[0124] The controller may be configured such that further actuation of the controller by the user (e.g., releasing the button) switches the movable plate 101 from the open position to the closed position. Releasing the button lifts the control arm 104 away from the connector 105 of the movable plate 101. Without the force of the control arm 104 on the movable plate 101, the spring element 102 biases the movable plate 101 to the closed position. As such, the user-actuable valve 100 is configured to allow the user to switch the valve from a closed configuration (movable plate 101 in the closed position) to an open configuration (movable plate 101 in the open position) or vice versa.

[0125] A user may close user-actuable valve 100 during a compression mixing operation. This may reduce the amount of water vapor lost from inside bioreactor 10 during such an operation. As previously detailed, during such a compression mixing operation, a differential pressure may increase. After the compression mixing operation is complete, a user may open user-actuable valve 100 to release pressure from bioreactor 10. Such a "breathing operation" may allow maximum air exchange with the contents of bioreactor vessel 12 and / or expansion vessel 14 and prevent significant differential pressure buildup.

[0126] 8a-10b, which are actuated by differential gas pressure, the actuation of user-actuable valve 100 is not dependent on differential gas pressure. User-actuable valve 100 may provide greater control over the environmental parameters acting on the contents of bioreactor vessel 12 and / or expansion vessel 14.

[0127] In one example, the inlet end 120 of the user-actuable valve 100 may be connected to an end of the gas outlet 26, and the outlet end 110 may be the free end at external pressure. Alternatively, the outlet end 110 may be connected to an end of the gas outlet 26, and the inlet end 120 may be the free end at external pressure.

[0128] In an alternative embodiment, the valve actuator may be configured to switch the movable plate 101 from the open position to the closed position upon pressing a button. For example, the control arm 104 may have a weight such that the weight of the control arm 104 on the movable plate 101 overcomes the spring force of the spring element 102. The controller may be configured to lift the control arm 104 away from the connector 105 upon pressing the button, switching the movable plate from the open position to the closed position. While the controller for the user-actuable valve 100 is described as a button, any suitable controller may be used instead, such as a lever, a dial, or an electronic controller. The user-actuable valve 100 described herein may be provided in the bioreactor 10 in place of or in addition to the flow restrictor 40, 50, or 60 or the valve 70, 80, or 90 of the previous embodiments.

[0129] Use of the bioreactor 10 of the present invention will be described with reference to Figures 1 through 10(b). In use, the bottom wall 15 of the compressible bioreactor vessel 12 is tilted and / or moved axially of the compressible bioreactor vessel 12 by an actuator. This movement of the bottom wall 15 compresses and / or expands the compressible bioreactor vessel 12. This may be done to mix or agitate fluids within the interior volume of the compressible bioreactor vessel 12, to control the volume of the compressible bioreactor vessel 12 before adding material to or extracting a sample from the compressible bioreactor vessel 12, or to perform one or more cell processing steps.

[0130] When the compressible bioreactor vessel 12 is compressed, the pressure within the compressible bioreactor vessel 12 increases, thereby forcing gas from the compressible bioreactor vessel 12 to the expansion vessel 14 to balance the pressure within the compressible bioreactor vessel 12 and the expansion vessel 14. A flow restrictor 40, 50, or 60 or a valve 70, 80, 90, or 100 according to any of the embodiments described above prevents gas from freely flowing out of the expansion vessel 14. When gas flow out of the expansion vessel 14 is restricted, the expansion vessel 14 expands to compensate for the pressure increase from the introduced gas. Thus, the flow restrictor 40, 50, 60 causes the expansion vessel 14 to expand, reducing the outflow of gas through the gas outlet 26 and thereby reducing vapor loss through the gas outlet 26. Similarly, valves 70, 80, 90, 100 block gas from flowing out of the expansion vessel when valves 70, 80, 90, 100 are closed, thereby causing expansion of expansion vessel 14 and preventing gas from flowing out through gas outlet 26 and vapor loss.

[0131] As the compressible bioreactor vessel 12 expands, the pressure within the compressible bioreactor vessel 12 decreases, thereby drawing gas from the expansion vessel 14 back into the compressible bioreactor vessel 12 and bringing the pressures within the compressible bioreactor vessel 12 and the expansion vessel 14 to equilibrium. A flow restrictor 40, 50, or 60, or a valve 70, 80, 90, or 100 according to any of the embodiments described above, prevents the free flow of gas from outside the bioreactor 10 into the expansion vessel 14. When the flow of gas into the expansion vessel 14 is restricted, the expansion vessel 14 contracts to compensate for the reduced pressure resulting from the displacement of gas from the expansion vessel 14.

[0132] The expansion vessel 14 may also be locked or held in a retracted position by the cage 29, thereby permitting gas exchange within the bioreactor 10. The expansion vessel 14 is first actuated to the retracted position by actuating the second cage section 29b to a first retracted position relative to the first cage section 29a, as shown in FIG. 1A. The second cage section 29b is locked or held in place relative to the first cage section 29a, preventing expansion of the expansion vessel 14. The bottom wall 15 of the compressible bioreactor vessel 12 is moved upwardly from the expansion vessel 14 by the actuator to compress the compressible bioreactor vessel 12, thereby increasing gas pressure at the outlet 26 and discharging gas from the headspace above the fluid within the interior volume of the bioreactor vessel 12 through the retracted expansion vessel 14 and the outlet 26. The bottom wall 15 of the compressible bioreactor vessel 12 is then moved downward by the actuator, away from the expansion vessel 14, expanding the compressible bioreactor vessel 12, thereby reducing the gas pressure at the outlet 26 and drawing ambient gas into the interior volume of the compressible bioreactor vessel 12 through the outlet 26 and the contracted expansion vessel 14. The second cage section 29b can then be released from the first contracted position such that the second cage section 29b is free to move relative to the first cage section 29a and the expansion vessel 14 is free to expand and contract.

[0133] Pressure Test Data Figure 12 shows the results of compression test data for three flow restrictors: a combination umbrella / duckbill valve (combination valve) with a 0.8 mm thick valve seat, a membrane valve with two slits (i.e., cross-shaped slits) in it, a restrictor with a 0.5 mm restricting diameter, and a control with no flow restrictor. The graph shows the load required to compress the bioreactor vessel for each of the flow restrictors.

[0134] The first test was performed by compressing the bioreactor vessel 12 at a rate of 2.5 mm / s, as indicated by the solid line. The second test was performed by compressing the bioreactor vessel 12 at a rate of 1.0 mm / s, as indicated by the dashed line. The expansion vessel 14 remained locked in the retracted position during this test.

[0135] The control without a flow restrictor requires minimal force to compress the bioreactor vessel, and the load increases relatively slowly as bioreactor displacement increases.

[0136] The force required to compress the bioreactor vessel with the membrane valve is slightly higher than that required for the control. The rate at which the load increases with increasing displacement of the bioreactor vessel is comparable to that of the control.

[0137] The force required to compress the bioreactor vessel with the combination valve is higher than that of the control. In one test, the force required to compress the combination valve is higher than that of the membrane valve at low displacement levels and is equivalent to that of the membrane valve at high displacement levels. In another test, the force required to compress the combination valve is higher than that of the membrane valve at all levels of displacement. The rate at which the load increases as the displacement of the bioreactor vessel increases is lower than that of the control and the membrane valve.

[0138] The force required to compress the combination valve is the highest, and the rate at which the load increases as the bioreactor vessel movement increases is also the highest.

[0139] Therefore, the membrane valve provides the least force required to compress the bioreactor vessel, which reduces the load on the actuator compressing the bioreactor vessel. The combination valve allows the bioreactor to be compressed at a more stable rate compared to other flow restrictors. This allows a more stable load to be applied by the actuator when compressing the bioreactor vessel, and also reduces the load required to compress the bioreactor vessel compared to a small diameter flow restrictor. A small diameter flow restrictor provides the most force required to compress the bioreactor.

[0140] According to the illustrated example, a filter is provided at the gas outlet 26 of the expansion vessel 14. In other examples, a filter may be provided at any suitable location between the flow restrictor 40, 50, or 60 or the valve 70, 80, or 90 and the fluid contained in the compressible bioreactor vessel 12 to prevent the introduction of contaminants into the fluid. For example, a filter may be provided at the flow restrictor 40, 50, or 60 or the valve 70, 80, or 90, a filter may be provided in the interface plate 13 between the expansion vessel 14 and the compressible bioreactor vessel 12, or a filter may be provided in the compressible bioreactor vessel 12 above the level of the fluid during use.

[0141] According to the illustrated example, the outlet 26 is provided in the expansion vessel 14. In other examples, the bioreactor does not include an expansion vessel and the outlet 26 is provided in the compressible bioreactor vessel 12, e.g., in the interface plate 13.

[0142] In general, those skilled in the art will appreciate that the above-described embodiments have been described by way of example only and not by way of limitation, and that various alternatives and modifications are possible without departing from the scope of the present invention as defined by the appended claims. Various modifications to the detailed designs as described above are possible, for example, variations in shape, size, arrangement, assembly, sequence, or the like may exist. For example, any one of an enclosure, planar interface, component-retaining element, or the like may be used in any suitable combination. Furthermore, while the present invention has been described in terms of an automated process, those skilled in the art will appreciate that a user may perform one or more of the above-described process steps manually or semi-automatically. [Explanation of symbols]

[0143] 10 Bioreactor 12 Compressible bioreactor vessel 13 Interface plate 14 Expansion vessel 15 Bottom wall 16 Compressible Sidewalls 16a Inward fold 16b Outward fold 17 Top 18 Compressible Sidewalls 18a Inward fold 18b Outward fold 19 Filters 20 Lower part 21 Aperture 22 ports 22 Baffle 23 Seal 24 Dip tube 25 Top Section 26 Gas outlet 27 First end 28 Second end 29 Cage 29a First cage section 29b Second cage section 30 Clamping Features 31 Baffle 32 Center part 33 Filter element 34 Hollow ring-shaped protrusion 40 Flow Restrictor 41 first end 42 Second end 50 Flow Restrictor 51 first end 52 Second end 60 Flow Restrictor 61 Elongated tube 62 first end portion 63 Tube support 64 Second end portion 65 Bent part 70, 80, 90 valve flow restrictor 70 Combination Umbrella and Duckbill Valves 71 Valve element 72 Support 73 Umbrella part 74 Duckbill part 75 Opening 76 Center opening 77 Valve seat 80 Elastic tightening valve 81 Resilient valve element 82 Compression Ring 90 Two-way ball valve 91 First ball valve 92 First spring element 93 First Ball Seat 94 Second Ball Valve 95 Second spring element 96 Second Ball Seat 97 Outlet end 98 Inlet end 100 User-actuable valve 101 Movable Plate 102 Spring element 103 Stickers 104 Control Arm 105 Connector 110 Outlet end 120 Inlet End

Claims

1. 1. A bioreactor comprising: a compressible bioreactor vessel configured to hold a cell suspension within an internal volume of the compressible bioreactor vessel, the compressible bioreactor vessel comprising a gas outlet in fluid communication with the internal volume of the compressible bioreactor vessel and configured, in use, to allow the exit of gas from the internal volume of the compressible bioreactor vessel; a bioreactor, wherein the gas outlet comprises a flow restrictor configured such that when the compressible bioreactor vessel is compressed in use, the flow restrictor restricts gas flow out of the gas outlet.

2. 10. The bioreactor of claim 1, further comprising an expandable expansion vessel having an interior volume fluidly connected to the interior volume of the compressible bioreactor vessel.

3. 3. The bioreactor of claim 2, wherein the expansion vessel comprises the gas outlet.

4. 4. The bioreactor of claim 2 or claim 3, wherein the compressible bioreactor vessel comprises a base section, a top section, and a compressible sidewall extending between the base section and the top section, and the expansion vessel is connected to the top section of the compressible bioreactor vessel.

5. 5. The bioreactor of claim 4, wherein the top section of the compressible bioreactor vessel comprises an interface plate having an opening, and the expansion vessel is attached to the interface plate at the opening such that the interior volume of the expansion vessel is fluidly connected to the interior volume of the compressible bioreactor vessel through the opening in the interface plate.

6. 6. The bioreactor of claim 5, wherein the expansion vessel comprises a base section, a top section, and a compressible sidewall extending between the base section and the top section, the base section being attached to the interface plate.

7. 7. The bioreactor of claim 5 or claim 6, wherein one or more ports are provided in the interface plate.

8. 8. The bioreactor of claim 1, wherein the flow restrictor comprises a valve.

9. 9. The bioreactor of claim 8, wherein the valve comprises a user-actuable valve, the actuation of which is independent of a gas pressure differential across the valve.

10. 9. The bioreactor of claim 8, wherein the valve allows gas to flow into and / or out of the gas outlet when a gas differential pressure at the gas outlet is at or above a threshold differential pressure.

11. 11. The bioreactor of claim 8, wherein the valve is a two-way valve.

12. 12. The bioreactor of claim 11, wherein the valve comprises a combination of an umbrella valve and a duckbill valve.

13. 8. The bioreactor of claim 1, wherein the flow restrictor comprises a flow-restricting pathway having a restricted diameter.

14. 14. The bioreactor of claim 13, wherein the restriction diameter is between about 0.15 mm and about 1.5 mm.

15. 15. The bioreactor of claim 14, wherein the restriction diameter is between about 0.5 mm and about 1.0 mm.

16. 16. The bioreactor of any one of claims 13 to 15, wherein the gas outlet has an outlet diameter and the restriction diameter is smaller than the outlet diameter.

17. 17. The bioreactor of any one of claims 1 to 16, wherein the flow restrictor comprises a porous structure configured to restrict gas flow out of the outlet.

18. 18. The bioreactor of claim 17, wherein the porous structure is a sintered material.

19. 19. The bioreactor of any one of claims 1 to 18, wherein the flow restrictor is disposed within the gas outlet, for example, pressed into the gas outlet.

20. 20. The bioreactor of any one of claims 1 to 19, wherein the flow restrictor is disposed above the gas outlet, for example, pressed onto an outer surface of the gas outlet.

21. 19. The bioreactor of any one of claims 1 to 18, wherein the flow restrictor is integrally formed with the gas outlet.

22. 16. The bioreactor of any one of claims 1 to 7 and 13 to 15, wherein the flow restrictor comprises a tube fluidly connected to the gas outlet.

23. 23. The bioreactor of claim 22, wherein the inner diameter of the tube is between about 0.2 mm and about 1 mm.

24. 24. The bioreactor of claim 23, wherein the inner diameter of the tube is about 0.5 mm.

25. 25. The bioreactor of any one of claims 22 to 24, wherein the length of the tube is at least about 100 mm, for example between about 100 mm and about 700 mm.

26. 26. The bioreactor of claim 25, wherein the length of the tube is between about 300 mm and about 500 mm.

27. 27. The bioreactor of any one of claims 1 to 26, further comprising a filter disposed in a gas flow path between the internal volume of the compressible bioreactor vessel and the gas outlet and / or the flow restrictor.

28. 28. The bioreactor of claim 27, wherein the filter is provided in the gas outlet.

29. 29. The bioreactor of any one of claims 1 to 28, further comprising one or more ports for introducing and / or removing materials into and / or from the interior volume of the compressible bioreactor vessel.

30. 1. A method of mixing a cell suspension in a bioreactor, comprising: providing a bioreactor comprising a compressible bioreactor vessel having a gas outlet including a flow restrictor; introducing a cell suspension into an interior volume of the compressible bioreactor vessel; compressing the compressible bioreactor vessel to reduce the interior volume of the compressible bioreactor vessel; restricting gas flow through the gas outlet with the flow restrictor while compressing the compressible bioreactor vessel; A method comprising:

31. 31. The method of claim 30, wherein the compressible bioreactor vessel includes an expansion vessel having an interior volume fluidly connected to the interior volume of the compressible bioreactor vessel, the method comprising transferring gas from the interior volume of the compressible bioreactor vessel to the interior volume of the expansion vessel upon compression of the compressible bioreactor vessel.

32. 32. The method of claim 30 or claim 31, wherein the flow restrictor includes a valve, and restricting the gas flow through the gas outlet with the flow restrictor includes blocking gas flow through the valve when a gas differential pressure at the gas outlet is below a threshold differential pressure, and allowing gas to flow through the valve when the gas differential pressure at the gas outlet is at or above the threshold differential pressure.

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