WO2023017260A1

WO2023017260A1 - A culture device

Info

Publication number: WO2023017260A1
Application number: PCT/GB2022/052080
Authority: WO
Inventors: Farlan VERAITCH
Original assignee: Oribiotech Ltd
Priority date: 2021-08-12
Filing date: 2022-08-10
Publication date: 2023-02-16
Also published as: GB2609648A; GB2609648B; GB202111585D0

Abstract

There is provided a culture device (10) having a base wall (12), and a compressible wall element (14) extending from the base wall in an axial direction and defining an internal volume of the device, the compressible wall element being compressible in the axial direction, the base wall including a first culture surface (28), a second culture surface (30), separated from the first culture surface, and a fulcrum (F) in between the culture surfaces, such that at least one of the culture surfaces is pivotable about the fulcrum.

Description

A CULTURE DEVICE

INTRODUCTION

[001] The present invention relates to a culture device, particularly for culturing cells, and a method of culturing cells.

BACKGROUND

[002] It is generally known in the field of cell culture that cellular growth proceeds from a so-called initial “lag phase”, in which cells adapt to the culture environment and adopt a slow growth rate, to a so-called “log phase”, in which cells proliferate exponentially and consume nutrients in their growth medium. As the cells consume the nutrients in their growth medium, it becomes necessary to remove the spent medium and introduce fresh growth medium in order to ensure that the cells continue to proliferate. Furthermore, as the density of the cell culture increases as cells proliferate, it becomes necessary to transfer the cell culture from one culture device to another, larger, culture device, having fresh growth medium therein. This process is known as passaging of the cell culture. This is also required for adherent-type cell cultures, in which cells adhere, or attach, to an appropriate surface. In adherent-type cell cultures, the adherent-type cells will proliferate and eventually occupy the entirety of the surface area available within a culture device. Thus, it becomes necessary to transfer the adherent-type cell culture from one surface to another, larger, surface in order to maintain a desired proliferation rate.

[003] Generally, the passaging process involves transferring cells from one culture container to another, often larger, container. This process is further complicated for adherent-type cells, in which cells that are adhered, or attached, to a surface must be dissociated, or detached, from such a surface prior to transferring to another culture container. There are many dissociation procedures known in the art, such as shaking or agitating the culture vessel, vigorous pipetting, scraping of the cells from the surface, or enzymatic dissociation using reagents such as Trypsin, Dispase, TrypLE™ (ThermoFisher Scientific), collagenase, ethylenediaminetetraacetic acid (EDTA), or Accutase™ (Innovative Cell Technologies).

[004] The current process of transferring cells between various culture containers has many disadvantages. Firstly, there is a risk that the cells are introduced into, or through, a non-sterile environment, through the use of interconnecting tubing, additional containers or other devices which may not be adequately sterilised prior to use. Secondly, the process of transferring cells requires manual intervention, especially in the context of adherent-type cell cultures, which hence introduces the risk of operator error, and potentially compromising sterility, during use. Thirdly, cell yields are often detrimentally affected by such a transferring process, since it is difficult to ensure that most, or all, of the cells have been removed from the first container, and then transferred to the second container. In particular, cells are often lost through pipette ends, tubing or the like during the transfer process. Fourthly, in currently known culture containers, it is often cumbersome to remove the finalised cellular product from the container at the end of the process. Often, cells are removed by pipetting, or through pumping mechanisms, which can introduce an extra layer of complexity to the system, having an associated risk of compromising sterility and being at risk of operator error.

[005] Therefore, it is an object of the present invention to solve, or at least mitigate, the abovementioned drawbacks. In particular, it is an object of the present invention to provide a culture device and method which avoids the need for cells to be transferred or passaged between two or more culture devices, for example, two, three, four or more culture devices. More particularly, it is an object of the present invention to provide a culture device and method in which cells can be passaged, or otherwise moved, within a single culture device, thereby ensuring an aseptic environment and higher cell yields. Such a culture device and method may also be more suited to automation. It is also an object of the present invention to provide a culture device in which material, for example cells, is more easily removed. It is yet a further object of the present invention to provide a culture device in which material, for example cells, can be mixed, resuspended in medium, or otherwise agitated

SUMMARY OF INVENTION

[006] According to one aspect of the present invention, there is provided a culture device comprising: a base wall; and a compressible wall element extending from the base wall in an axial direction and defining an internal volume of the device, the compressible wall element being compressible in the axial direction, wherein the base wall comprises a first culture surface, a second culture surface, separated from the first culture surface, and a fulcrum disposed therebetween, such that at least one of the first culture surface and the second culture surface is pivotable about the fulcrum.

[007] That is, the present invention provides a device suitable for culturing material. The device includes a base wall including a fulcrum about which at least one culture surface is pivotable, tiltable or otherwise moveable. The fulcrum is generally positioned between two, or more, culture surfaces. The fulcrum may assume the form of a point, such as a central origin of the base wall, an axis, a plane or the like. The culture surface may be pivotable, tiltable or otherwise moveable with respect to a horizontal plane in which the base wall is disposed, for example, prior to pivoting, tilting or the like. As such, the culture surface may be pivotable, tiltable or the like with respect to a horizontal or transverse plane, particularly about a predetermined angle.

[008] This provides the advantage that a cell culture can be transferred, or passaged, between the two culture surfaces within a single culture device. Accordingly, the requirement of multiple culture devices is avoided. In this way, the culture device ensures a continuous aseptic environment, reduces operator handling and thus associated errors, and is more suited to automated processes. Furthermore, this provides the advantage of enabling low volume cell cultures, such as suspension-type cell cultures, to be mixed, agitated or resuspended prior to addition of further cell culture medium into the container. For example, volumes of approximately 10 mL to approximately 200 mL of settled suspension-type cells may be resuspended within their medium, prior to addition of further medium into the container, often referred to as “expansion” of the volume.

[009] In some embodiments, each culture surface is independently pivotable about the fulcrum.

[010] This provides the advantage that a cell culture can be transferred between either the first and second cell surfaces, or both the first and second cell surfaces.

[011] In certain embodiments, the culture device is configured such that the first culture surface and/or the second culture surface are pivotable about an angle from 1 degree to 45 degrees with respect to a transverse plane, defined by the base wall, extending substantially perpendicularly to a central longitudinal axis of the culture device. Preferably, the angle is from 5 degrees to 25 degrees. Most preferably, the angle is approximately 10 degrees. Herein, the angle formed may be a positive or negative angle with respect to the transverse plane. The culture device may be configured for pivoting about such an angle through the configuration and modification of the compressible side wall, such as the size, shape, flexibility and the like of the same.

[012] In certain embodiments, a surface area of the first culture surface and a surface area of the second culture surface are equal. In other embodiments, the surface area of the first culture surface and the surface area of the second culture surface are non-equal.

[013] In some embodiments, a ratio between a surface area of the first culture surface and a surface area of the second culture surface is from approximately 1 :9 to approximately 1 :1.

[014] In certain embodiments, the ratio is approximately 1 :9, 1 :8, 1 :7, 1 :6, 1 :5, 1 :4, 1 :3, 1 :2 or 1 :1. It will be appreciated that such a ratio may represent the surface area of the first culture surface with respect to the second culture surface, or the second culture surface to the first culture surface.

[015] In certain embodiments, the fulcrum is defined by an axis located within a transverse plane, defined by the base wall, extending substantially perpendicularly to a central longitudinal axis of the culture device.

[016] In certain embodiments, the axis intersects the central longitudinal axis.

[017] In certain embodiments, the fulcrum is defined by a point located within a transverse plane, defined by the base wall, extending substantially perpendicularly to a central longitudinal axis of the culture device.

[018] In certain embodiments, the fulcrum is a first fulcrum, and wherein the base wall further comprises a third culture surface, separated from the second culture surface, and a second fulcrum disposed therebetween, such that at least one of the second culture surface and the third culture surface is pivotable about the second fulcrum.

[019] This provides the advantage that the cells may be further passaged to another culture surface, thereby avoiding the requirement of an additional container. [020] In certain embodiments, the second fulcrum is defined by an axis located within the transverse plane.

[021] In certain embodiments, the axis defining the first fulcrum is parallel with respect to the axis defining the second fulcrum.

[022] In certain embodiments, a ratio between a surface area of the first culture surface, the second culture surface and the third culture surface is approximately 1 :1 :1.

[023] In certain embodiments, a ratio between a surface area of the first culture surface, the second culture surface and the third culture surface is approximately 1 :2:3.

[024] This provides the advantage that the cells are transferred to increasingly larger surface areas as they proliferate.

[025] In certain embodiments, the base wall comprises a hinge element, extending between opposing sides of the base wall, thereby forming the fulcrum.

[026] In certain embodiments, the hinge element extends linearly between opposing sides of the base wall.

[027] In certain embodiments, the hinge element extends non-linearly between opposing sides of the base wall.

[028] In certain embodiments, the hinge element comprises a fold or a crease in the base wall.

[029] This provides the advantage that the base wall is continuous. Accordingly, the risk of culture material, such as cells, becoming trapped in discontinuous surfaces, such as joins or folds, is mitigated.

[030] In certain embodiments, the hinge element comprises a foldable region.

[031] In certain embodiments, the base wall further comprises at least one port.

[032] This provides the advantage that the material, such as cells, may be removed from the culture device. In particular, the at least one port is advantageous in combination with the pivotable culture surface(s), as cells may be directed towards the at least one port, thereby ensuring maximum harvesting of the material.

[033] In certain embodiments, the or each port is coincident with the fulcrum.

[034] This provides the advantage that the maximum amount of culture material is harvested from the culture device. In particular, the first culture surface and/or the second culture surface may be pivoted so as to direct the material towards the port, thereby ensuring maximum harvesting efficiency.

[035] In certain embodiments, the compressible wall element comprises a corrugated wall. In certain embodiments, the compressible wall element comprises a bellows side-wall. The bellows sidewall may include a series of deformable regions interleaved with rigid sections. The compressible wall element, such as a bellows side-wall, may be held within an external supporting, optionally surrounding, frame.

[036] This provides the advantage that the compressible wall element is moveable in response to the pivoting of the first culture surface and/or the second culture surface. This also provides the advantage of providing a compressible culture device which can be compressed and/or extend by external forces to encourage mixing of the contents.

[037] In certain embodiments, the compressible wall element comprises a flexible wall element, a flexible bag, a flexible membrane, or the like. The wall element, bag or membrane may be resiliently deformable. The flexible wall element, such as the flexible bag or membrane, may be held within an external, optionally surrounding, supporting frame.

[038] In certain embodiments, the first culture surface and/or the second culture surface comprises an adherent cell culture substrate or coating.

[039] This provides the advantage that the culture device is suitable for adherent-type cells, which can thus be passaged between the culture surfaces within the culture device.

[040] In certain embodiments, the adherent cell culture substrate or coating comprises an extracellular matrix.

[041] In certain embodiments, the adherent cell culture substrate or coating is selected from the group comprising collagen, fibronectin, vitronectin, laminin, gelatine, poly-lysine, cellulose, or a combination thereof.

[042] In certain embodiments, the base wall comprises polystyrene, polycarbonate, low-density polyethylene, high-density polyethylene, silicone, or a thermoplastic elastomer. In particular embodiments, the base wall comprises silicone, particularly a substantially gas-permeable silicone. In more particular embodiments, the base wall comprises silicone coated on an external, or outer, surface thereof with a substantially gas-impermeable coating. In yet more particular embodiments, the base wall comprises a substantially gas-impermeable thermoplastic elastomer.

[043] The above materials provide multiple advantages. For example, the base wall being comprised of polystyrene allows for adherent-type cells to be directly adhered to the culture surface(s), thereby mitigating the need for an additional substrate or coating. Moreover, the base wall being comprised of silicone provides gas-permeability at the base of the culture device, thereby avoiding hypoxic conditions during use of the culture device. Yet further, the base wall being comprised of a thermoplastic elastomer provides the necessary biocompatibility and mechanical integrity for the base of the device, but may provide a gas-impermeable base, which may be advantageous to particular materials to be cultured within the device.

[044] In certain embodiments, the culture device comprises a top wall, spaced apart from the base wall by the compressible wall element. As such, the top wall is disposed at a distal end of the compressible wall element, and the base wall is disposed at a proximal end of the compressible wall element. The top wall may include an opening. The opening may be threaded either internally or externally.

[045] In accordance with another aspect of the present invention, there is provided a system for culturing cells comprising: a culture device as described herein; and an interface plate operably coupled to a top wall of the culture device.

[046] In certain embodiments, the interface plate is threadingly coupled to a threaded opening of the culture device, optionally formed in the top wall thereof.

[047] In certain embodiments, the interface plate comprises one or more ports for the ingress and/or egress of material to/from the culture device. Preferably, the one or more ports comprise septum seals.

[048] In accordance with another aspect of the present invention, there is provided a system for culturing cells comprising: a culture device as described herein; and an actuator configured to engage at least a portion of the base wall, such that at least one of the first culture surface and the second culture surface is caused to pivot about the fulcrum, during use.

[049] This provides the advantage that the pivoting of the first and second culture surfaces can be controlled by the actuator, either through manual or automatic manipulation of the actuator.

[050] In certain embodiments, the actuator is electrically coupled to a processor. In particular embodiments, the processor is configured to actuate the actuator according to a pre-defined set of parameters. In other embodiments, the processor may be electrically coupled to one or more sensors of the culture device. In such embodiments, the processor may be configured to receive a signal from the one or more sensors and actuate the actuator in response to the received signal.

[051] In certain embodiments, the actuator is further configured to engage the entirety of the base wall, such that the entirety of the base wall is caused to translate in the axial direction, during use.

[052] This provides the advantage that the entirety of the base wall is translated, thereby allowing for the mixing of the contents of the culture device by compressing and/or extending the compressible wall of the culture device.

[053] In certain embodiments, the system further comprises an interface plate as discussed in the above aspect.

[054] In accordance with another aspect of the present invention, there is provided a kit of parts comprising: a culture device as described herein; and an interface plate as described herein, arranged to operably couple to the culture device, and/or an actuator as described herein, arranged to cause pivoting of at least one of the first culture surface and the second culture surface about the fulcrum, during use.

[055] In accordance with another aspect of the present invention, there is provided a method of culturing cells, comprising the steps of: culturing cells within a medium for a first pre-determined period of time on at least one of a first culture surface and a second culture surface of a culture device; pivoting at least one of the first culture surface and the second culture surface about a fulcrum to cause turbulence of the cellular culture, thereby mixing the same.

[056] This provides the advantage that the contents of the culture device can be agitated, mixed, or the like.

[057] In certain embodiments, the cells are suspension-type cells.

[058] In accordance with another aspect of the present invention, there is provided a method of culturing cells, comprising the steps of: culturing cells for a first pre-determined period of time on at least one of a first culture surface and a second culture surface of a culture device; pivoting at least one of the first culture surface and the second culture surface about a fulcrum to move cells between the respective culture surfaces of the culture device; culturing cells for a second pre-determined period of time on at least one of the first culture surface and the second culture surface of the culture device.

[059] This provides the advantage that the cells are mixed and, for suspension-type cells, resuspended in media.

[060] In accordance with another aspect of the present invention, there is provided a method of culturing cells, comprising the steps of: culturing cells on a first culture surface of a culture device; pivoting the first culture surface about a fulcrum to move the cells to a second culture surface of the culture device; and culturing the cells on the second culture surface.

[061] This provides the advantage that a cell culture can be transferred, or passaged, between the two culture surfaces without the need to transfer cells to a further container. Accordingly, this method ensures a continuous aseptic environment, reduces operator handling and thus associated errors, and is more suited to automated processes. Yet further, the cell culture can be mixed or, in the case of suspension-type cell cultures, resuspended.

[062] In certain embodiments, the first culture surface is pivoted about an angle from 1 degree to 45 degrees with respect to a transverse plane extending substantially perpendicularly to a central longitudinal axis of the culture device. Preferably, the angle is from 5 degrees to 25 degrees. Most preferably, the angle is approximately 10 degrees. Herein, the angle formed may be a positive or negative angle with respect to the transverse plane.

[063] In certain embodiments, the method further comprises a step of introducing media into the culture device. In certain embodiments, the method further comprises a step of removing media from the culture device.

[064] In certain embodiments, the method further comprises a step of genetically modifying cellular material within the culture device.

[065] In certain embodiments, the method further comprises a step of introducing a virus and/or magnetic beads into the culture device.

[066] In certain embodiments, the method further comprises a step of introducing growth factors, cytokines or the like into the culture device.

[067] In certain embodiments, the method further comprises a step of removing material, such as the cells, from the culture device. In such a step, the first culture surface and/or the second culture surface may be pivoted about the fulcrum to direct material towards a port disposed on the base wall of the culture device.

[068] In accordance with another aspect of the present invention, there is provided a method of culturing adherent-type cells, comprising the steps of: culturing adherent-type cells on a first culture surface of a culture device; detaching the adherent-type cells from the first culture surface; pivoting the first culture surface about a fulcrum to move the adherent-type cells to a second culture surface of the culture device; culturing the cells on the second culture surface.

[069] This provides the advantage that a cell culture can be transferred, or passaged, between the two culture surfaces without the need to transfer cells to a further container. Accordingly, this method ensures a continuous aseptic environment, reduces operator handling and thus associated errors, and is more suited to automated processes.

[070] In certain embodiments, the first culture surface is pivoted about an angle from 1 degree to 45 degrees with respect to a transverse plane extending substantially perpendicularly to a central longitudinal axis of the culture device. Preferably, the angle is from 5 degrees to 25 degrees. Most preferably, the angle is approximately 10 degrees.

[071] In certain embodiments, prior to the step of detaching the adherent-type cells from the first culture surface, there is provided a step of washing the adherent-type cell culture. In some embodiments, the step of washing may include introducing a washing solution, such as a buffered saline solution, into the culture device. The step of washing may also include removing the washing solution from the culture device.

[072] In certain embodiments, the step of detaching the adherent-type cells from the first culture surface comprises introducing a dissociation reagent into the culture device. In some embodiments, the dissociation reagent comprises Trypsin, Dispase, TrypLE™, collagenase, EDTA, or Accutase™, or the like. Generally, any appropriate dissociation reagent or method for detaching the adherent-type cells may be utilised.

[073] In embodiments of the invention, any cell type may be cultured in the culture device, including adherent-type cells and/or suspension-type cells.

[074] In embodiments of the invention, any adherent-type cells may be cultured in the culture device. The adherent-type cells may include one or more of mesenchymal stem cells, induced pluripotent stem (IPS) cells, embryonic stem cells (ESCs), cancer cells lines, human embryonic kidney (HEK) cells, HeLa cells, fibroblasts, or epithelial cells, or the like

[075] In certain embodiments, the method for comprises: culturing adherent-type cells on a first substrate disposed on the first culture surface; and/or culturing adherent-type cells on a second substrate disposed on the second culture surface.

[076] In certain embodiments, the method further comprises a step of introducing media into the culture device. In certain embodiments, the method further comprises a step of removing media from the culture device.

[077] In certain embodiments, the method further comprises a step of genetically modifying cellular material within the culture device.

[078] In certain embodiments, the method further comprises a step of introducing a virus and/or magnetic beads into the culture device.

[079] In certain embodiments, the method further comprises a step of introducing growth factors, cytokines or the like into the culture device.

[080] In certain embodiments, the method further comprises a step of removing material, such as the cells, from the culture device. In such a step, the cells may be detached from the respective culture surface, and then the first culture surface and/or the second culture surface may be pivoted about the fulcrum to direct material towards a port disposed on the base wall of the culture device. [081] In certain embodiments, the method discussed herein are carried out in the culture device discussed herein.

[082] Generally, the methods discussed herein can be carried out in any appropriate order. Yet further, the methods discussed herein may comprise further steps of passaging cells on to further culture surfaces, for example third or fourth culture surfaces, as required.

BRIEF DESCRIPTION OF THE DRAWINGS

[083] Example embodiments of the invention are now described, by way of example only, hereinafter with reference to the accompanying drawings, in which:

Figure 1 illustrates a side view of a culture device according to the present invention;

Figure 2 illustrates a side view of the culture device of Figure 1 having an interface plate attached;

Figure 3 illustrates a top view of the culture device of Figure 1 ;

Figure 4 illustrates a cross-sectional view of the culture device of Figure 1 having an interface plate attached, in a first configuration;

Figure 5 illustrates a cross-sectional view of the culture device of Figure 1 having an interface plate attached, in a second configuration;

Figure 6 illustrates a side view of another culture device according to the present invention having an interface plate attached;

Figure 7 illustrates a top view of the culture device of Figure 6;

Figure 8 illustrates a side view of another culture device according to the present invention having an interface plate attached;

Figure 9 illustrates a top view of the culture device of Figure 8;

Figure 10 illustrates a top view of another culture device according to the present invention;

Figure 11 illustrates a top view of another culture device according to the present invention;

Figure 12 illustrates a top view of another culture device according to the present invention;

Figure 13 illustrates a top view of (a) another culture device according to the present invention, having three culture surfaces; and (b) yet another culture device according to the present invention, having three culture surfaces;

Figure 14 illustrates a top view of (a) another culture device according to the present invention, having four culture surfaces; and (b) yet another culture device according to the present invention, having four culture surfaces; and Figure 15 illustrates a top view of (a) a square base wall, (b) another square base wall, (c) a triangular base wall, and (d) an octagonal base wall of various culture devices according to the present invention.

DETAILED DESCRIPTION

[084] The described example embodiment relates to a culture device and a method. They primarily relate to devices and methods in cell processing, particularly cell and/or gene therapy, but are not limited thereto. As will be appreciated by the person skilled in the art, the present culture device and method are readily applicable to adherent-type cells, suspension-type cells, human-derived cells, animal-derived cells, and the like. The present device and method may be utilised in cell and/or gene therapy, tissue engineering, cellular agriculture, including laboratory or cell grown meat products, water treatment and other like technical fields. Moreover, the present culture device may be presented as merely a device, which may be suitable in other fields, such as chemical processing, agriculture and the like. The present device and method is not limited to any one particular use as described herein.

[085] Certain terminology is used in the following description for convenience only and is not limiting. The words ‘upper’, ‘lower’, ‘upwardly and ‘downwardly’ designate directions in the drawings to which reference is made and are with respect to the described component when assembled and mounted. The words ‘inner’, 'inwardly' and ‘outer’, ‘outwardly’ refer to directions toward and away from, respectively, a designated centreline or a geometric centre of an element being described (e.g. a central axis), the particular meaning being readily apparent from the context of the description. Further, the terms ‘proximal’ (i.e. nearer to) and ‘distal’ (i.e. away from) designate positions relative to a body or a point of attachment.

[086] Further, as used herein, the terms ‘connected¹, ‘affixed’ and the like are intended to include direct connections between two members without any other members interposed therebetween, as well as, indirect connections between members in which one or more other members are interposed therebetween. The terminology includes the words specifically mentioned above, derivatives thereof, and words of similar import.

[087] Further, unless otherwise specified, the use of ordinal adjectives, such as, ‘first’, ‘second’, ‘third’ etc. merely indicate that different instances of like objects are being referred to and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking or in any other manner. Like reference numerals are used to depict like features throughout.

[088] Figures 1 and 2 illustrate a culture device 10 including a base wall 12 and a compressible wall element 14. The compressible wall element 14 extends along a central longitudinal axis L of the culture device, that is in an axial direction, from the base wall 12. The compressible wall element 14 extends from a proximal end, adjacent and connected to the base wall 12, towards a distal end. The distal end includes an opening 16, the internal circumference of which may be threaded. The compressible wall element 14 is formed as a bellows side wall and includes a series of deformable regions 18 interleaved with rigid regions 20 therebetween. The culture device 10 also includes a plurality of optional ports 22, shown in Figure 2, and optionally formed as septum seals, for the ingress and/or egress of material to/from the culture device 10.

[089] Generally, the base wall 12 comprises a rigid material and the compressible wall element 14 comprises a resilient material. The base wall 12 may be composed of polystyrene, polypropylene, polycarbonate, low or high density polyethylene (LDPE or HDPE), a thermoplastic elastomer, silicone or the like. The compressible wall element 14 may be composed of silicone, a substantially gas- permeable or substantially gas-impermeable thermoplastic elastomer, a flexible polymeric film, or the like. Any combination of materials for the base wall 12 and the compressible wall element 14 is contemplated.

[090] With particular reference to Figure 2, the culture device 10 includes an interface plate 24 coupled to the opening 16 thereof. The interface plate 24 may be threadingly coupled to the threaded interior of the opening 16. Equally, other couplings, such as a push fit or clip fit, are contemplated. The interface plate 24 comprises a plurality of ports 26, optionally formed as septum seals, for the ingress and/or egress of material through the interface plate 24 and into the culture device 10. The plurality of ports 26 may provide access to the culture device 10 through the use of a needle-based connector (not shown).

[091] Figure 3 illustrates a top view of the culture device 10 illustrated in Figures 1 and 2. As shown in Figure 3, the culture device 10 includes a first culture surface 28 and a second culture surface 30 separated by a fold line 32. The first culture surface 28 and the second culture surface 30 may be of the same, or a different, material. In some examples, particularly relevant for culturing adherent-cell types, the first culture surface 28 and/or the second culture surface 30 include a coating or substrate to allow for cell attachment, or are composed of appropriate materials to allow for cell attachment, such as polystyrene. The fold line 32 generally forms a fulcrum F defined as an axis extending within the plane of the base wall 12. The fulcrum F extends perpendicular to, and intersects, a central longitudinal axis L of the culture device 10 (see Figure 1 ). The culture device 10 includes the plurality of ports 22 disposed along the fold line 32, that is, coincident with the fulcrum F. In the present example, three ports 22 are shown, but more, less, or no ports are equally contemplated.

[092] Figure 4 illustrates the culture device 10 in a first configuration, in which the first culture surface 28 has been pivoted about the fulcrum F, namely the fold line 32, about an angle a with respect to a horizontal plane B of the base wall 12. The second culture surface 30 is retained within the horizontal plane B. That is, in the present example, the first culture surface 28 is pivoted with respect to the second culture surface 30. The first culture surface 28 is pivotable by virtue of the fold line 32 and the compressible wall element 14. In particular, the compressible wall element 14 adjacent the first culture surface 28 is caused to compress, thereby providing pivoting about the fulcrum F. As such, during use, cells residing on the first culture surface 28 are passaged towards, and on to, the second culture surface 30. [093] Figure 5 illustrates the culture device 10 in a second configuration, in which the second culture surface 30 has been pivoted about the fulcrum F, namely the fold line 32, about an angle p with respect to the horizontal plane B of the base wall 12. The first culture surface 28 is retained within the horizontal plane B. That is, in the present example, the second culture surface 30 is pivoted with respect to the first culture surface 28. The second culture surface 30 is pivotable by virtue of the fold line 32 and the compressible wall element 14. In particular, the compressible wall element 14 adjacent the second culture surface 30 is caused to compress, thereby providing pivoting about the fulcrum F. As such, during use, cells residing on the second culture surface 30 are passaged towards, and on to, the first culture surface 28.

[094] Figures 6 and 7 illustrate another embodiment of a culture device 10, which is identical to the culture device of Figures 1 to 5, except in that fulcrum F, the fold line 32 and the ports 22 are positioned off-centre within the base wall 12. That is to say, the fulcrum F, formed by the fold line 32, extends along an axis which is non-intersecting with respect to the central longitudinal axis L of the culture device 10 (see Figure 1). In such an embodiment, the first culture surface 28 has a smaller surface area than the second culture surface 30. In the particular example, the second culture surface 30 is about three times larger than the first culture surface 28. In this way, cells may initially be grown upon the smaller, first, culture surface 28, and then transferred to the second, larger, culture surface 30 following a period of proliferation.

[095] Figure 8 illustrates a culture device 10, which is identical to the culture devices of Figures 1 to 5, except in that there are no ports present in the base wall 12. Instead, only a fold line 32 is present in the base wall 12. In order to remove material from the culture device 10, the entirety of the base wall 12 is translated longitudinally, along the central longitudinal axis L, towards the interface plate 24, thereby compressing the compressible wall element 14. As such, material is caused to be pushed outwardly, through one or more of the ports 26 in the interface plate 24. Equally, in order to input material into the culture device 10, the entirety of the base wall 12 is translated longitudinally, along the central longitudinal axis, away from the interface plate 24, thereby extending the compressible wall element 14. As such, material is caused to be drawn into the culture device 10, through the use of negative pressure, through one or more of the ports 26 of the interface plate 24.

[096] Figures 9 to 11 each illustrate a culture device assuming a generally circular base wall 12 and each including a fold line 32 separating the first and second culture surfaces 28, 30. As shown in Figure 9, the fold line 32 extends linearly across the diameter of the base wall 12, between diametrically opposing edges thereof. As shown in Figure 10, the fold line 32 extends linearly across a chord of the base wall 12, between opposing edges thereof. As shown in Figure 11 , the fold line 32 extends non-linearly across the diameter of the base wall 12, between diametrically opposing edges thereof. The non-linear fold line 32 may extend sinusoidally, as illustrated in Figure 11. Equally, although not shown, the fold line 32 may generally extend across a chord of the base wall 12, between opposing edges thereof, i.e. non-diametrically opposing edges. [097] Figure 12 illustrates a culture device assuming a generally circular base wall 12 and including a first foldable element 40 and a second foldable element 42. The first and second foldable elements 40, 42 generally extend as a sector of the base wall 12, thereby separating the base wall 12 into a first culture surface 28, formed as a first culture sector of the base wall 12, and a second culture surface 30, formed as a second culture sector of the base wall 12. The first foldable element 40 comprises a flexible or resilient piece of material 40a extending between the first and second culture surfaces 28, 30. The second foldable element 42 comprises a flexible or resilient piece of material 42a extending between the first and second culture surfaces 28, 30. The flexible or resilient pieces of material 40a, 42a may be formed as a flexible film or a bellows i.e. having a concertina including convolutes. In this way, the entirety of the first culture surface 28 and/or the second culture surface 30 may pivot about the fulcrum formed as the central origin O, by virtue of the flexible materials 40a, 42a within the foldable elements 40, 42.

[098] Figures 13(a) and 13(b) illustrate a culture device including three culture surfaces: a first culture surface 28, a second culture surface 30, and a third culture surface 34. The first culture surface 28 is separated from the second culture surface 30 by a first fold line 32. The second culture surface 30 is separated from the third culture surface 34 by a second fold line 36. As shown in Figure 13(a), the first fold line 32 and the second fold line 36 each extend across a chord of the generally circular base wall 12, and are parallel with respect to one another. The first, second and third culture surfaces 28, 30, 34 each have an approximately equal surface area, such that the ratio between the first, second and third culture surfaces 28, 30, 34 is approximately 1 :1 :1. As shown in Figure 13(b), in another example, the first fold line 32 extends across a chord of the generally circular base wall 12, and the second fold line 36 extends across a diameter of the generally circular base wall 12. Thus, the first fold line 32 and the second fold line 36 extend parallel with respect to one another. The first, second and third culture surfaces 28, 30, 34 each have an increasingly larger surface area, such that the ratio between the first, second and third culture surfaces 28, 30, 34 is approximately 1 :2:3.

[099] Figures 14(a) and 14(b) illustrate a culture device including four culture surfaces: a first culture surface 28, a second culture surface 30, a third culture surface 34, and a fourth culture surface 38. There are also provided four foldable elements: a first foldable element 40, a second foldable element 42, a third foldable element 44 and a fourth foldable element 46. The first culture surface 28 is separated from the second culture surface 30 by the first foldable element 40. The second culture surface 30 is separated from the third culture surface 34 by a second foldable element 42. The third culture surface 34 is separated from the fourth culture surface 38 by the third foldable element 44. The fourth culture surface 38 is separated from the first culture surface 28 by the fourth foldable element 46. Each foldable element 40, 42, 44, 46 includes a flexible or resilient piece of material as described in relation to Figure 12 above.

[100] As shown in Figure 14(a), the first and third foldable elements 40, 44 are parallel to one another and intersect at a central origin O of the base wall 12. Similarly, the second and fourth foldable elements 42, 46 are parallel to one another and intersect at the central origin O of the base wall 12. The central origin O forms the fulcrum in this example. The second and fourth foldable elements 42, 46 extend substantially perpendicularly with respect to the first and third foldable elements 40, 44. As such, each culture surface 28, 30, 34, 38 is separated from one another by a respective foldable element 40, 42, 44, 46 and, more specifically, each culture surface 28, 30, 34, 38 is provided as a separate quarter section, or sector, of the base wall 12, each having identical surface areas.

[101] As shown in Figure 14(b), the first and third foldable elements 40, 44 are parallel to one another and intersect at an intersecting point P of the base wall 12. Similarly, the second and fourth foldable elements 42, 46 are parallel to one another and intersect at the intersecting point P of the base wall 12. The intersecting point P is non-coincidental with central origin O shown in Figure 14(a). The second and fourth foldable elements 42, 46 extend substantially non-perpendicularly with respect to the first and third foldable elements 40, 44. As such, each culture surface 28, 30, 34, 38 is separated from one another by a respective foldable element 40, 42, 44, 46 and, more specifically, each culture surface 28, 30, 34, 38 is provided as having a different surface area.

[102] Generally, in the examples of Figure 14(a) and 14(b), each culture surface 28, 30, 34, 38 is pivotable about the fulcrum formed by the origin O (Figure 14(a)) or the intersecting point P (Figure 14(b)). As discussed in relation to Figure 12, the foldable elements 40, 42, 44, 46 each include flexible or resilient material to allow the respective culture surface 28, 30, 34, 38 to be raised, or translated in the axial direction, thereby causing pivoting about the respective fulcrum.

[103] Figures 15(a) to 15(d) illustrate different cross-sectional shapes of the base wall 12 in a culture device, each having a fold line 32 separating a first culture surface 28 from a second culture surface 30. Figure 15(a) illustrates a generally square base wall 12 including a fold line 32 extending between opposing sides of the square base wall 12. Figure 15(b) illustrates a generally square base wall 12 including a fold line 32 extending between adjacent sides of the square base wall 12. Figure 15(c) illustrates a generally triangular base wall 12 including a fold line 32 extending between adjacent sides of the triangular base wall 12. Figure 15(d) illustrates a generally octagonal base wall 12 including a fold line 32 extending between generally opposing corners of the octagonal base wall 12. As will be recognised by those skilled in the art, the base wall 12 may assume any geometry or cross-sectional profile, and the fold line 32 may extend between any appropriate edges, sides, corners or the like of such base walls 12.

[104] The presently described culture devices of Figures 1 to 15 may be used to passage cells in the following manner. In the particular exemplary protocols discussed below, reference is made to the use of the culture device 10 of Figures 1 to 5, although such use is equally applicable to the culture devices of Figures 6 to 15.

Protocol 1 : suspension-type cell culture

[105] In one example, a suspension-type cell culture, i.e. a suspension of cells of a desired type within an appropriate medium, is introduced into the cell culture device 10 shown in Figures 1 and 2. In particular, a cell culture may be loaded into the volume of the culture device 10 from an external receptacle having a needle-based connector (not shown). The needle-based connector may cause piercing of a septum seal within the external receptacle, and also may cause piercing of one of the ports 26 of the interface plate 24, thereby fluidly connecting the external receptacle and the culture device 10. Accordingly, the cell culture is introduced into the culture device 10.

[106] The cells within the cell culture are allowed to settle onto the base wall 12, namely on each of the culture surfaces 28, 30. Optionally, the second culture surface 30 is pivoted about the fold line 32 by angle p (Figure 5) so that all cells reside on the first culture surface 28. Alternatively, the culture device 10 may be titled in its entirety so that cells settle and reside on the first culture surface 28. In some particular examples, cells are allowed to settle, and thus proliferate, on both the first culture surface 28 and the second culture surface 30.

[107] The cells in culture are allowed to proliferate, such that exponential growth of cells is achieved. During proliferation, appropriate materials, such as growth factors, fresh medium, proteins, magnetic beads, antibodies, viruses or the like, may be added to the cell culture. Such materials may be introduced from an external receptacle having a needle-based connector analogously to the introduction of the cell culture discussed above. During proliferation, the first culture surface 28 may be pivoted about the fold line 32 in a cyclical manner for the purposes of mixing and/or resuspending the cell culture. Generally, cyclical pivoting about the fold line 32 may induce turbulence within the cell culture device 10 to provide mixing and/or resuspension of the contents therein. The cyclical pivoting about the fold line 32 may be provided between an angle, formed by the first culture surface 28 with respect to the second culture surface 30, of +10 degrees and -10 degrees. The second culture surface 30 may be provided static, and at a fixed angle with respect to, or within, the horizontal plane. In one particular example, the second culture surface 30 is provided at a fixed angle with respect to the horizontal plane so that the cells continue to be held over the first culture surface 28 during cyclical pivoting of the first culture surface 28. The cell culture is allowed to proliferate until a desired cell density is achieved.

[108] Optionally, a medium exchange step is provided. In particular, a portion of the cell culture medium, i.e. medium that is exhausted or spent, is removed from the culture device 10 and replaced with fresh medium. The medium may be removed through port 22 of the culture device 10, or through the port 26 of the interface plate 24. Fresh medium is introduced through the port 26 of the interface plate 24, through the use of an external receptacle having a needle-based connector, analogous to the introduction of the cell culture discussed above. Equally, as would be recognised by those skilled in the art, a medium exchange step may be provided after the passaging of the cells as discussed below. In some examples, a medium exchange step may be provided both prior to, and after, the passaging of the cells as discussed below.

[109] The culture device 10, specifically the first culture surface 28 thereof, is pivoted about the fold line 32, i.e. about the fulcrum F. In particular, an actuator (not shown) may cause pivoting of the first culture surface 28. The actuator may be provided as a paddle-based actuator, a linear-actuator or the like. The first culture surface 28 is pivoted at an angle of approximately 10 degrees with respect to the horizontal plane B, as shown in Figure 4. In this way, the cells are transferred, or passaged, from the first culture surface 28 to the second culture surface 30, by virtue of gravity, so that all of the cells reside on the second culture surface 30. The cell culture may then be allowed to proliferate until a desired cell density is achieved. During proliferation, the second culture surface 30 may be pivoted about the fold line 32 in a cyclical manner for the purposes of mixing and/or resuspending the cell culture. Generally, cyclical pivoting about the fold line 32 may induce turbulence within the cell culture device 10 to provide mixing and/or resuspension of the contents therein. The cyclical pivoting about the fold line 32 may be provided between an angle, formed by the second culture surface 30 with respect to the first culture surface 28, of +10 degrees and -10 degrees. The first culture surface 28 may be provided static, and at a fixed angle with respect to, or within, the horizontal plane. In one particular example, the first culture surface 28 is provided at a fixed angle with respect to the horizontal plane so that the cells continue to be held over the second culture surface 30 during cyclical pivoting of the second culture surface 30.

[110] Optionally, further transferring, or passaging, of the cells may take place, namely from the second culture surface 30 back to the first culture surface 28. In particular, the second culture surface 30 is pivoted about the fold line 32, i.e. about the fulcrum F. More particularly, an actuator (not shown) may cause pivoting of the second culture surface 30. The second culture surface 30 is pivoted at an angle of approximately 10 degrees with respect to the horizontal plane B, as shown in Figure 5. In this way, the cells are transferred, or passaged, from the second culture surface 30 back to the first culture surface 28, by virtue of gravity, so that all of the cells reside on the first culture surface 28. In this way, a mixing action is achieved, which may promote oxygenation of the cell culture. The cell culture is allowed to proliferate until a desired cell density is achieved.

[111] Yet further, the pivoting about the fold line 32, i.e. about fulcrum F, of the first culture surface 28 and/or the second culture surface 30 may carried out for the purposes of mixing and/or resuspending the cell culture. Accordingly, following pivoting, the cells may be allowed to settle on each of the first and second culture surfaces 28, 30, rather than preferential settling on a particular culture surface.

[112] Finally, once the cell culture has reached maturity and the desired density has been achieved, the cell culture is harvested through the port 22 of the culture device 10. In particular, each culture surface 28, 30 may be actuated, by an actuator (not shown), such that they each pivot about the fold line 32, i.e. fulcrum F. In this way, the first culture surface 28 is provided at angle a and the second culture surface 30 is provided at angle p. Any appropriate angle may be utilised. For example, angle a may be 45 degrees, and angle p may be 45 degrees. Accordingly, the cell culture is directed, through gravity, towards and through the port 22.

Protocol 2: adherent-type cell culture

[113] In another example, an adherent-type cell culture, i.e. adherent-type cells within an appropriate medium, is introduced into the cell culture device 10 shown in Figures 1 and 2. The cell culture device 10 includes a coating or substrate on each of the first and second culture surfaces 28, 30 to allow for cell adhesion thereto. In particular, the cell culture may be loaded into the volume of the culture device 10 from an external receptacle having a needle-based connector (not shown). The needle-based connector may cause piercing of a septum seal within the external receptacle, and also may cause piercing of one of the ports 26 of the interface plate 24, thereby fluidly connecting the external receptacle and the culture device 10.

[114] The cells within the cell culture are allowed to settle onto the base wall. One, or both, of the culture surfaces 28, 30 may be pivoted about fold line 32, i.e. about fulcrum F, as shown in Figures 4 and 5, to ensure that the adherent-type cells reside on the coating or substrate of the first culture surface 28. Alternatively, the culture device 10 may be titled in its entirety so that cells settle, and adhere to, the coating or substrate on the first culture surface 28.

[115] The cell culture is allowed to proliferate, namely through adherence to the first culture surface 28, such that exponential growth of cells is achieved. The cells may be allowed to adhere to, and proliferate on, the first culture surface 28 for a specified period, for example for a period of 10 minutes to 24 hours, and preferably for a period of 6 to 12 hours. During proliferation, appropriate materials, such as growth factors, fresh medium, proteins, magnetic beads, antibodies, viruses or the like, may be added to the cell culture. Such materials may be introduced from an external receptacle having a needle-based connector analogously to the introduction of the cell culture discussed above. The cell culture is allowed to proliferate until a desired cell density is achieved.

[116] Optionally, a medium exchange step is provided prior to passaging of the cells from first culture surface 28 to second culture surface 30. In particular, a portion of the cell culture medium, i.e. medium that is exhausted or spent, is removed from the culture device 10 and replaced with fresh medium. The medium may be removed through port 22 of the culture device 10, or through the port 26 of the interface plate 24. Fresh medium is introduced through the port 26 of the interface plate 24, through the use of an external receptacle having a needle-based connector, analogous to the introduction of the cell culture discussed above. Equally, as would be recognised by those skilled in the art, a medium exchange step may be provided after the passaging of the cells as discussed below. In some examples, a medium exchange step may be provided both prior to, and after, the passaging of the cells as discussed below.

[117] Prior to the transferring, or passaging, of the adherent-type cells from the first culture surface 28 to the second culture surface 30, the cell culture is washed. In particular, all of, or a portion of, the cell culture medium is removed from the culture device 10, through the port 22 of the culture device or one of the ports 26 of the interface plate 24. Subsequently, a wash solution is introduced into the culture device 10. The wash solution may be a buffered saline solution, for example, phosphate buffered saline. Generally, any suitable wash solution may be used to ensure the removal of any agents, such as serum, calcium or magnesium, that would inhibit the action of the dissociation reagent discussed below. The culture device 10 is gently agitated, for example, through rocking, in order to wash the cell culture. The wash solution is then removed from the culture device 10, through the port 22 of the culture device 10 or one of the ports 26 of the interface plate 24. [118] Following washing, and prior to passaging of the adherent-type cells, a dissociation reagent is added to the culture device 10. The dissociation reagent may be pre-warmed to a temperature of 37 degrees Celsius prior to addition. The dissociation reagent may be trypsin or TrypLE™, or another reagent to provide dissociation of adherent-type cells from the coating or substrate on the first culture surface 28. The culture device 10 is gently agitated, for example, through rocking or pivoting of one or both culture surfaces 28, 30, to ensure complete dissociation of the cells from the first culture surface 28. The culture device 10 may also be incubated at room temperature for a period of time.

[119] Upon detachment of the adherent-type cells from the first culture surface 28, the first culture surface 28 is pivoted about the fold line 32, i.e. about the fulcrum F. In particular, an actuator (not shown) may cause pivoting of the first culture surface 28. The first culture surface 28 is pivoted at an angle of approximately 10 degrees with respect to the horizontal plane B, as shown in Figure 4. In this way, the cells are transferred, or passaged, from the first culture surface 28 to the second culture surface 30, by virtue of gravity, so that all of the cells reside on the second culture surface 30. Fresh cell culture medium may also be added to the culture device through one of the ports 26 in the interface plate 24 at this stage. The adherent-type cells are then allowed to adhere to the coating or substrate on the second culture surface 30. The cells are allowed to adhere and proliferate for a specified period, for example for a period of 10 minutes to 24 hours, and preferably for a period of 6 to 12 hours. Once the cells have been allowed to adhere for the specified period of time, the cell culture medium containing the dissociation reagent is removed through port 22 of the culture device 10, or through the port 26 of the interface plate 24. Fresh cell culture medium is then introduced through the port 26 of the interface plate 24, through the use of an external receptacle having a needle-based connector, analogous to the introduction of the cell culture discussed above, and the cells are allowed to proliferate on the coating or substrate on the second culture surface 30. During proliferation, appropriate materials, such as growth factors, fresh medium, proteins, magnetic beads, antibodies, viruses or the like, may be added to the cell culture. Such materials may be introduced from an external receptacle having a needle-based connector analogously to the introduction of the cell culture discussed above. The cell culture is allowed to proliferate until a desired cell density is achieved.

[120] Finally, once the cell culture has reached maturity and the desired density has been achieved, the cell culture may be harvested through the port 22 of the culture device 10. In particular, the washing and dissociation steps discussed above may be applied to the cell culture residing on the coating or substrate on the second culture surface 30, thereby ensuring appropriate dissociation of the adherent-type cells from the same. Subsequently, each culture surface 28, 30 may be actuated, by an actuator (not shown), such that they each pivot about the fold line 32, i.e. fulcrum F. In this way, the first culture surface 28 is provided at angle a and the second culture surface 30 is provided at angle p. Any appropriate angle may be utilised. For example, angle a may be 45 degrees, and angle may be 45 degrees. Accordingly, the cell culture is directed, through gravity, towards and through the port 22. [121] Although the above example protocols describe two culture surfaces, the skilled person would equally apply the above teachings to any number of culture surfaces. Moreover, the above example protocols may be carried out in any device described herein. Yet further, the example protocols may be followed in any order, for example, suspension- or adherent-type cells may be cultured firstly on the second culture surface 30, followed by passaging to the first culture surface 28. In yet further protocols, the cells may not be passaged, but may instead simply allowed to proliferate and then directed, through pivoting of the culture surfaces 28, 30 about the fold line 32, i.e. fulcrum F, towards and through port 22 for harvesting. In other words, the presently described device and methods may allow for passaging and/or harvesting of cellular material.

[122] It will be appreciated by persons skilled in the art that the above embodiments have been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departing from the scope of the invention as defined by the appended claims. Various modifications to the detailed designs as described above are possible, for example, variations may exist in shape, size, material, arrangement, assembly or the like.

Claims

1 . A culture device comprising: a base wall; and a compressible wall element extending from the base wall in an axial direction and defining an internal volume of the device, the compressible wall element being compressible in the axial direction, wherein the base wall comprises a first culture surface, a second culture surface, separated from the first culture surface, and a fulcrum disposed therebetween, such that at least one of the first culture surface and the second culture surface is pivotable about the fulcrum.

2. The culture device according to claim 1 , wherein each culture surface is independently pivotable about the fulcrum.

3. The culture device according to claim 1 or claim 2, wherein a ratio between a surface area of the first culture surface and a surface area of the second culture surface is from approximately 1 :9 to approximately 1 :1.

4. The culture device according to claim 3, wherein the ratio is approximately 1 :3.

5. The culture device according to any one of the preceding claims, wherein the fulcrum is defined by an axis located within a transverse plane, defined by the base wall, extending substantially perpendicularly to a central longitudinal axis of the culture device.

6. The culture device according to claim 5, wherein the axis intersects the central longitudinal axis.

7. The culture device according to any one of claims 1 to 4, wherein the fulcrum is defined by a point located within a transverse plane, defined by the base wall, extending substantially perpendicularly to a central longitudinal axis of the culture device.

8. The culture device according to any preceding claim, wherein the fulcrum is a first fulcrum, and wherein the base wall further comprises a third culture surface, separated from the second culture surface, and a second fulcrum disposed therebetween, such that at least one of the second culture surface and the third culture surface is pivotable about the second fulcrum.

9. The culture device according to claim 8, when dependent upon claim 5 or claim 6, wherein the second fulcrum is defined by an axis located within the transverse plane.

10. The culture device according to claim 9, wherein the axis defining the first fulcrum is parallel with respect to the axis defining the second fulcrum.

11 . The culture device according to any one of claims 8 to 10, wherein a ratio between a surface area of the first culture surface, the second culture surface and the third culture surface is approximately 1 :2:3.

12. The culture device according to any one of the preceding claims, wherein the base wall comprises a hinge element, extending between opposing sides of the base wall, thereby forming the fulcrum.

13. The culture device according to claim 12, wherein the hinge element extends linearly between opposing sides of the base wall.

14. The culture device according to any one of claims 12 or claim 13, wherein the hinge element comprises a fold in the base wall.

15. The culture device according to any preceding claim, wherein the base wall further comprises at least one port.

16. The culture device according to claim 15, wherein the or each port is coincident with the fulcrum.

17. The culture device according to any one of the preceding claims, wherein the compressible wall element comprises a corrugated wall.

18. The culture device according to any one of the preceding claims, wherein the first culture surface and/or the second culture surface comprises an adherent cell culture substrate or coating.

19. The culture device according to claim 18, wherein the adherent cell culture substrate or coating comprises an extracellular matrix.

20 The culture device according to claim 18 or claim 19, wherein the adherent cell culture substrate or coating is selected from the group comprising collagen, fibronectin, vitronectin, laminin, gelatine, poly-lysine, cellulose, or a combination thereof.

21. The culture device according to any one of the preceding claims, wherein the base wall comprises polystyrene, polycarbonate, low-density polyethylene, high-density polyethylene, silicone, or a thermoplastic elastomer.

22. A system for culturing cells comprising: the culture device according to any one of claims 1 to 21 ; and an actuator configured to engage at least a portion of the base wall, such that at least one of the first culture surface and the second culture surface is caused to pivot about the fulcrum, during use.

23. A method of culturing cells, comprising the steps of: culturing cells on a first culture surface of a culture device; pivoting the first culture surface about a fulcrum to move the cells to a second culture surface of the culture device; and culturing the cells on the second culture surface.

24. A method of culturing adherent-type cells, comprising the steps of: culturing adherent-type cells on a first culture surface of a culture device; detaching the adherent-type cells from the first culture surface; pivoting the first culture surface about a fulcrum to move the adherent-type cells to a second culture surface of the culture device; culturing the cells on the second culture surface.

25. The method of claim 23 or claim 24, wherein the method is carried out in the culture device according to any one of claims 1 to 21.