Closure for bioreactor
By providing a closure that can be connected to the container, the closure that includes an impeller and a gas delivery device, the problem of insufficient flexibility and high cost of the prior art small and medium-sized bioreactors is solved, and a flexible, economical and suitable for cell culture is realized.
Patent Information
- Application Number
- CN202380053021.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-07-14
- Filing Date
- 2023-06-26
- Publication Date
- 2025-02-28
AI Technical Summary
In the prior art, there are problems of insufficient flexibility and high cost when developing small bioreactors, and different sizes of bioreactors are required at different research stages, but existing small bioreactors are expensive and inflexible.
A closure for a bioreactor is provided, the closure being connected to a container to form a bioreactor. The closure includes an impeller device and a gas delivery device, which can adjust the length of the impeller shaft to accommodate containers of different sizes, and promote gas distribution through the gas delivery device.
A flexible small bioreactor is realized, capable of adapting to containers of different sizes, reducing costs and providing a closed and sterile treatment environment suitable for cell culture.
Smart Images
Figure CN119546741A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a closure for a bioreactor, a bioreactor and a method for converting a container into a bioreactor. Background Art
[0002] Small bioreactors are sometimes required for process development applications in different areas of research. Different stages of the development process often require bioreactors of different sizes.
[0003] Shake flasks can be used for small scale culture, such as for volumes between 25-250 mL. However, this is an uncontrolled process. 15 and The 250 and 250 are two examples of controllable small-scale bioreactors. However, these bioreactors are expensive and for some applications, bioreactors of other sizes may be required. Summary of the invention
[0004] The object of the present invention is to provide a flexible small-scale bioreactor.
[0005] Yet another object of the present invention is to provide a method for converting a container into a bioreactor.
[0006] This is achieved by a closure for a bioreactor, a bioreactor and a method according to the independent claims.
[0007] According to one aspect of the present invention, there is provided a closure for a bioreactor, the closure being configured to be connected to a container such that the closure and the container together constitute the bioreactor. The closure comprises an inner surface which will face the interior of the bioreactor when the closure is connected to the container, and an outer surface which will form part of the outer surface of the bioreactor when the closure is connected to the container.
[0008] The closure may include: (i) an impeller device, which includes an impeller shaft and impeller blades mounted on the impeller shaft, wherein the impeller device is mounted to the inner surface of the closure so that when the closure is connected to the container, the impeller shaft and the impeller blades protrude into the container; and (ii) a gas delivery device, which includes a gas inlet, a gas outlet and a gas delivery channel extending between the gas inlet and the gas outlet, wherein the gas inlet is arranged at the outer surface of the closure, and the gas delivery channel is arranged in the closure so that it extends from the gas inlet at the outer surface of the closure to the inner surface of the closure and protrudes from the inner surface so that when the closure is connected to the container, the gas outlet of the gas delivery channel is arranged inside the container.
[0009] According to another aspect of the present invention, there is provided a bioreactor comprising a container connected to a closure according to the present invention.
[0010] According to another aspect of the present invention, there is provided a method for converting a container into a bioreactor, the method comprising the step of attaching a closure according to the present invention to a container, thereby providing a bioreactor.
[0011] Therefore, a closure (such as a cap or lid) is provided, which can be used with a container for providing a bioreactor. The container does not need to be modified into a bioreactor in any particular way. The container only needs to be compatible with the closure so that they can be connected to each other. In addition, the container needs to be made of a suitable material that can be sterilized and provide a sterile environment to the bioreactor culture to be maintained in the bioreactor. The impeller device and the gas delivery device are each arranged in the closure so that the container does not need to include or have such parts integrated thereon. Suitably, all features required for cell culture are included in the closure, and therefore the container itself does not need any specific modification or any bioreactor feature. Any container can be used as a bioreactor with the closure, as long as it can be connected to the closure. Containers of different sizes can be used with the same closure, as long as the container can be connected to the closure. By providing such a design and arrangement, a flexible and cost-effective bioreactor is realized. For example, users can use the containers they already have. The container can be a bottle of any size (for example, with an internal volume between 250mL-2L). In addition, the closure and bioreactor according to the present invention are suitable for providing a closed and sterile processing environment for culturing cells.
[0012] In one embodiment of the invention, the impeller shaft is telescopic so that the length of the impeller shaft can be adjusted. The adjustability allows the closure to be used with containers of different sizes (eg, heights).
[0013] In one embodiment of the present invention, the impeller shaft comprises a hollow outer shaft and an inner shaft, the hollow outer shaft being connected to the inner surface of the enclosure, the inner shaft being telescopically arranged inside the hollow outer shaft so that it can protrude from the hollow outer shaft to different amounts. The inner shaft is connected to the impeller blades, and the inner shaft is mounted to the hollow outer shaft so that it can rotate about the longitudinal center axis A of the impeller shaft, thereby mixing the contents of the bioreactor.
[0014] In one embodiment of the invention, the gas delivery channel of the gas delivery device is arranged inside the impeller device. The gas outlet of the gas delivery device can be arranged at the end of the impeller device so that the gas can be delivered into the bioreactor close to the bottom of the bioreactor, which promotes gas distribution.
[0015] In one embodiment of the invention, the closure further comprises a sensor assembly comprising at least one sensor. The sensor assembly is arranged in the closure such that when the closure is connected to the container, the at least one sensor is disposed inside the container.
[0016] In one embodiment of the invention, the sensor assembly comprises at least one sensor access channel, the at least one sensor access channel being arranged in the closure such that it extends from an outer surface of the closure to an inner surface of the closure and protrudes from the inner surface of the closure. The at least one sensor is arranged in the at least one sensor access channel such that when the closure is connected to the container, the at least one sensor can be used to measure a characteristic of the contents provided in the bioreactor and such that the sensor can be accessed from the outer surface of the closure via the sensor access channel.
[0017] In one embodiment of the invention, at least one sensor comprises a pH value, dissolved oxygen (DO) and / or a temperature sensor. At least one sensor may also comprise an imaging or optical sensor for determining, for example, cell density, viable cell density, analyte concentration, etc. The sensor may be an optical sensor or a chemical electrical sensor.
[0018] In one embodiment of the invention, the gas inlet is configured to be connected to an external gas source.
[0019] In one embodiment of the invention, the impeller means comprises at least one magnetic element, such that when the closure is connected to the container, the impeller can be driven (ie rotated) by applying an external magnetic field from outside the container.
[0020] In one embodiment of the present invention, the closure further comprises a securing mechanism for securing the closure to the container.
[0021] In one embodiment of the invention, the closure is configured to be connected to a container that is a bottle.
[0022] In one embodiment of the invention, the closure is configured to be connected to a container having an interior volume between 50 mL-2L. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1a-1c 2 are different schematic diagrams of a closure according to an embodiment of the present invention.
[0024] Figure 2a A closure according to one embodiment of the invention is schematically shown, connected to a container, together forming a bioreactor.
[0025] Figure 2b A closure according to one embodiment of the invention is schematically shown, connected to a container, together forming a bioreactor.
[0026] Figure 2c A closure according to one embodiment of the invention is schematically shown, connected to a container, together forming a bioreactor.
[0027] Figure 3 is a flow chart of a method according to one embodiment of the present invention. DETAILED DESCRIPTION
[0028] According to the present invention, a closure 1; 1' for a bioreactor and a bioreactor 200; 200'; 200" comprising such a closure 1; 1' are provided. Figure 1a-1c In FIG. 1 , an embodiment of a closure 1 according to the invention is shown. Figure 2a-2c In the figure, different embodiments of bioreactors 200; 200'; 200" according to the present invention are shown. Figure 2a and 2b The display includes Figure 1a-1c The bioreactor 200; 200' of the enclosure 1 is shown in FIG. Figure 2c In the figure, a bioreactor 200 is shown including different embodiments of a closure 1' according to the present invention. Many details of the embodiments of the closure 1; 1' are the same or similar and are given the same or similar figure marks, and a description thereof may be provided for only one embodiment, but explicitly applies to all embodiments unless otherwise stated in this document.
[0029] The closure 1; 1' according to the present invention is configured to be connectable to a container 100; 100'; 100", so that the closure 1; 1' and the container 100; 100'; 100" together constitute a bioreactor 200; 200'; 200". The closure 1; 1' comprises an inner surface 3a and an outer surface 3b, and when the closure 1; 1' is connected to the container 100; 100'; 100", the inner surface 3a will face the interior of the bioreactor 200; 200'; 200", and when the closure 1; 1' is connected to the container 100; 100'; 100", the outer surface 3b will form part of the outer surface of the bioreactor 200; 200'; 200". The closure 1; 1' may be, for example, a cap or a cover, and may be connected to the container 100; 100'; 100" by any suitable fixing mechanism 41; 41' (e.g., a thread, a clamp, a latch, etc.). In the example Figure 1a-1c In the embodiment of the closure 1 shown in , the securing means 41 are cooperating threads on the container 100 ; 100 ′ and the closure 1 . Figure 2cAnother example of a securing mechanism 41' comprising a latching mechanism is shown in FIG. 1 . A magnetic lock is another example of a securing mechanism that may be used. The container 100; 100'; 100" may be, for example, a bottle, a can, a box, or another type of container. In some examples, the same closure 1; 1' may be connected to containers 100; 100'; 100" of different sizes. This is Figure 2a and 2b 1 is shown in which the same closure 1 is connected to two differently sized containers 100; 100' in the form of bottles with different heights and volumes. The invention is particularly suitable for process development and therefore the internal volume of the containers 100; 100'; 100" may suitably range between, for example, 50 mL - 2 L. Due to the closure and bioreactor according to the invention, the closure and aseptic processing of the bioreactor culture is possible. For example, the closure may be pre-sterilized or it may be sterilized together with the container during an autoclave.
[0030] The closure 1; 1 ' comprises an impeller device 11, which comprises an impeller shaft 13 and impeller blades 15 mounted on the impeller shaft 13. The impeller device 11 is mounted to the inner surface 3a of the closure 1; 1 ' so that when the closure 1; 1 ' is connected to the container 100; 100'; 100", the impeller shaft 13 and the impeller blades 15 protrude into the container 100; 100'; 100". The closure 1; 1 ' also comprises a gas delivery device 21, which comprises a gas inlet 23, a gas outlet 25 and a gas delivery channel 27 extending between the gas inlet 23 and the gas outlet 25. The gas inlet 23 is arranged at the outer surface 3b of the closure 1; 1', and the gas delivery channel 27 is arranged in the closure 1; 1' so that it extends from the gas inlet 23 at the outer surface 3b of the closure 1; 1' to the inner surface 3a of the closure 1; 1' and protrudes from the inner surface 3a, so that when the closure 1; 1' is connected to the container 100; 100'; 100", the gas outlet 25 of the gas delivery channel 22 is arranged inside the container 100; 100'; 100". The gas inlet 23 can be configured to be connected to an external gas source.
[0031] According to an embodiment, the impeller shaft 13 is telescopic so that the length of the impeller shaft 13 can be adjusted. As shown in the figure and discussed in more detail below, the impeller shaft 13 includes a hollow outer shaft 13a and an inner shaft 13b, the hollow outer shaft 13a is connected to the inner surface 3a of the closure 1; 1', and the inner shaft 13b is telescopically arranged inside the hollow outer shaft 13a so that it can protrude from the hollow outer shaft 13a to different lengths. This is the case for both embodiments of the closure 1; 1' as shown in Figures 1 and 2. However, in another embodiment, the impeller shaft 13 may have a fixed length. The benefit of having a telescopic impeller shaft 13 is that the length of the impeller shaft 13 can be adjusted for containers 100; 100'; 100" of different sizes. This is in Figure 2a , 2b and 2c, where the impeller shaft 13 extends different amounts. The impeller blades 15 can be arranged close to the bottom 102 of the container 100; 100'; 100", which is generally appropriate. The bioreactor can be filled with different amounts of culture medium. In addition, as will be further described below, the gas outlet 25 of the gas delivery device 21 (if integrated with the impeller device 11) can also be arranged close to the bottom 102 of the container 100; 100'; 100", so that the gas can be bubbled through a significant portion of the culture medium.
[0032] In some embodiments, the impeller blades 15 are integrally attached to the impeller. In other embodiments, the impeller blades may be attached to the impeller via hinges so that the impeller blades 15 can be folded upward toward the impeller shaft 13. By attaching the impeller blades to the impeller 11 with hinges, the length of the blades 15 can be increased while still allowing them to pass through the opening in the container 100; 100'; 100". This is particularly beneficial when the container has a small opening but a larger capacity (wherein a larger impeller blade 15 is necessary in order to ensure proper mixing).
[0033] In some embodiments, (as shown in the two embodiments of the closure 1; 1 ' shown in Figures 1 and 2) the impeller shaft 13 comprises a hollow outer shaft 13a and an inner shaft 13b, the hollow outer shaft 13a being connected to the inner surface 3a of the closure 1; 1 ', and the inner shaft 13b being telescopically arranged inside the hollow outer shaft 13a so that it can protrude from the hollow outer shaft 13a to different lengths. As used herein, "telescopically" should mean that the inner shaft 13b can slide relative to the outer shaft 13a. The inner shaft 13b is connected to the impeller blades 15, and the inner shaft 13b is mounted on the hollow outer shaft 13a so that it can rotate around the longitudinal center axis A of the impeller shaft 13. In some embodiments, the impeller shaft 13 can automatically adjust to the size of the container 100; 100'; 100" (for example, by gravity pulling the inner shaft 13b downward). The inner shaft 13b and the hollow outer shaft 13a are suitably arranged concentrically. The inner shaft 13b can have a cylindrical form, and the hollow outer shaft 13a can have a hollow cylindrical form. An o-ring or some other type of bearing element can be provided between the inner shaft 13a and the outer shaft 13b so that the outer shaft 13a and the inner shaft 13b maintain a consistent concentric orientation (for example, the inner shaft 3b cannot adopt an angled orientation relative to the outer shaft 13a). However, this may not be necessary. Another alternative may be to use hydrophobic and / or hydrophilic materials for the inner shaft 13a and the outer shaft 13b, thereby avoiding leakage without the need for any mechanical seals.
[0034] In some embodiments, the impeller device 11 comprises a magnetic element 17 for allowing the impeller device 11 to be rotated about the longitudinal center axis A from outside the container 100; 100'; 100" by applying an external magnetic field when the closure 1; 1' is connected to the container 100; 100'; 100". The magnetic part 17 can be arranged at the end of the inner shaft 13b, as shown in the two embodiments of the closure 1; 1' shown in Figures 1 and 2. Thereby, when the closure 1; 1' is connected to the container 100; 100'; 100", the magnetic part 17 will be arranged close to the bottom 102 of the container 100; 100'; 100", and in this regard, a magnetic drive from below the bottom 102 of the container 100; 100'; 100" can be implemented in order to rotate the impeller to achieve mixing of the fluid in the bioreactor 1; 1'. Other possibilities for driving the impeller may be, for example, an electric motor connected to the impeller shaft 13 from the outer surface 3b of the closure 1; 1'.
[0035] In an embodiment, (and as shown for both embodiments of the enclosure 1 as shown in Figures 1 and 2) the gas delivery channel 27 of the gas delivery device 21 is arranged inside the impeller device 11. As described above, the telescopic impeller shaft 13 may be hollow so that the gas delivery channel 27 may be arranged to pass through the entire impeller shaft 13. The gas outlet 25 may be arranged at the end of the impeller shaft 13, below the impeller blades 15, and the gas may be delivered from there into the bioreactor 200; 200'; 200". Thereby, the delivery of the gas is arranged close to the bottom 102 of the container 100; 100'; 100" of the bioreactor 200; 200'; 200" and directly below the impeller blades 15, which is suitable for good gas distribution in the contents of the bioreactor. However, this is not necessarily the case in all embodiments. In another embodiment, the gas delivery device 21 may be a separate device.
[0036] The closure 1; 1' may be at least partially made of plastic material or possibly of metal.The closure should be suitable for sterilization.
[0037] In some embodiments of the present invention, (as shown for the two embodiments of the closure 1; 1' shown in Figures 1 and 2) the closure 1; 1' also includes a sensor assembly 31, which includes one or more sensors 33. The closure 1; 1' may include more than one sensor assembly 31. The sensor assembly 31 is arranged in the closure 1; 1' so that when the closure 1; 1' is connected to the container 100; 100'; 100", the one or more sensors 33 are set inside the container 100; 100'; 100". The sensor assembly 31 may include one or more sensor access channels 35, wherein the sensor access channels 35 are arranged in the closure 1; 1' so that they extend from the outer surface 3b of the closure 1; 1' to the inner surface 3a of the closure 1; 1' and protrude from the inner surface 3a of the closure 1; 1'. One or more sensors 33 are arranged in the sensor access channel 35 so that when the closure 1; 1' is connected to the container 100; 100'; 100", the sensor 33 can be used to measure characteristics of the contents provided in the bioreactor, and so that the one or more sensors 33 can be accessed from the outer surface 3b of the closure 1; 1' via the sensor access channel 35. Depending on the sensor technology and on what is being measured, the sensor may or may not need to be in direct contact with the bioreactor culture. For some types of sensors, the sensor needs to be in direct contact with the contents in the bioreactor. For such sensors, the sensor is mounted to the sensor access channel so that it is in direct contact with the contents in the bioreactor, and so that it It can be connected from the outside of the bioreactor via the sensor access channel 35. For other types of sensors (such as optical sensors), direct contact with the contents is not required, but the measurement can be performed through the transparent wall. In some embodiments of the present invention, the sensor access channel 35 and the impeller shaft 13 are connected to each other to form a baffle. This can be advantageous for providing better mixing in the bioreactor, because the fluid flow caused by the impeller will be interrupted, thereby achieving better mixing. However, in other embodiments, one or more sensor access channels 35 can be separated from the impeller shaft 13. According to the present invention, the baffle can also be arranged in the bioreactor in another way. For example, a hinged baffle connected to the impeller device can be provided, which can be automatically deployed by the vortex.
[0038] In some embodiments of the present invention, the sensor 33 includes a pH sensor and / or a DO sensor. Other sensors may also be provided, such as a temperature sensor and / or an imaging or optical sensor for determining, for example, cell density, viable cell density, analyte concentration. The sensor 33 may, for example, be an optical sensor or a chemical electrical sensor. Other types of sensors may also be provided, such as a resistive sensor or a colorimetric sensor. For an optical sensor, an optical fiber is arranged to pass through a sensor access channel 35 for connection to the optical sensor. Any number of sensors 33 and sensor access channels 35 may be provided. More than one sensor 33 may also be arranged to be connected to the same sensor access channel 35.
[0039] In some embodiments, the enclosure 1; 1 ' further comprises one or more access channels 36 for sampling and / or adding ingredients to the bioreactor contents, to enable, for example, the addition of fresh nutrient medium, to perform perfusion operations, for cleaning and / or for aseptic sampling. Two or more such access channels may potentially be used for a loop for continuous measurement of, for example, a carbon source (such as glucose) and / or a metabolite (such as lactate). Two access channels may also be used to run the bioreactor in a batch feeding or perfusion mode.
[0040] According to the present invention, a bioreactor 200; 200'; 200". The bioreactor 200; 200'; 200" comprises a closure 1; 1' and a container 100; 100'; 100" according to the present invention as described above, connected to each other. All bioreactor features (such as an impeller device 11, a gas delivery device 21 and a sensor assembly 31) are connected to the closure 1; 1', whereby the container can be an empty container, such as an ordinary bottle, that does not comprise any bioreactor features. The container can be made of a light-blocking material so that a light-sensitive nutrient medium can be used.
[0041] In an embodiment, the bioreactor 200; 200'; 200" may also include at least one baffle. The baffle may take the form of a flexible insert that can be placed inside the container 100; 100'; 100" and lined on its inner wall. In one example, the baffle includes a flexible annular insert that includes at least one protrusion.
[0042] According to the present invention, there is also provided a method for converting a container 100; 100'; 100" into a bioreactor 200; 200'; 200". Figure 3 The flow chart of the method is shown in FIG. The method comprises the following steps:
[0043] S1: Attaching a closure 1; 1' according to the invention to a container 100; 100'; 100", thereby providing a bioreactor 200; 200'; 200". As described above, the container 100; 100'; 100" may be an empty container, such as an ordinary bottle which is not particularly suitable as a bioreactor.
[0044] The method may further comprise the following steps:
[0045] S2: Adjust the length of the impeller shaft 13 according to the size of the container 100; 100'; 100".
[0046] The bioreactor 200; 200'; 200" can then be used to culture cells according to well-known processes. The bioreactor 200; 200'; 200" can be connected to a control system for controlling the process for culturing cells, such as controlling the gas supply (e.g., air, O2, N2 or CO2), adding other components (e.g., nutrients, pH adjusters or new cell nutrient medium), sampling, etc., for example depending on the sensor output, as described above. Such control systems are well known in the art and will not be further described here. Thereby, for example, the pH and DO in the cell culture can be controlled.
Claims
1. A closure (1; 1') for a bioreactor (200; 200'; 200"), the closure (1; 1') being configured to be connectable to a container (100; 100'; 100") such that the closure (1; 1') and the container (100; 100'; 100") together constitute the bioreactor (200; 200'; 200"), wherein the closure (1; 1') comprises: The inner surface (3a) is formed when the closure member (1; 1') is connected to the container (100; 100'; 100″), the inner surface (3a) will face the interior of the bioreactor (200; 200′; 200″); and an outer surface (3b) which will form part of the outer surface of the bioreactor (200; 200′; 200″) when the closure (1; 1′) is connected to the container (100; 100′; 100″), and wherein the closure (1; 1′) comprises: an impeller device (11) comprising an impeller shaft (13) and impeller blades (15) mounted on the impeller shaft (13), wherein the impeller device (11) is mounted on the inner surface (3a) of the closure (1; 1') such that when the closure (1; 1') is connected to the container (100; 100'; 100"), the impeller shaft (13) and the impeller blades (15) protrude into the container (100; 100'; 100"); A gas delivery device (21), comprising a gas inlet (23), a gas outlet (25) and a gas delivery channel (27) extending between the gas inlet (23) and the gas outlet (25), wherein the gas inlet (23) is arranged at the outer surface (3b) of the closure (1; 1'), and the gas delivery channel (27) is arranged in the closure (1; 1') so that it extends from the gas inlet (23) at the outer surface (3b) of the closure (1; 1') to the inner surface (3a) of the closure (1; 1') and protrudes from the inner surface (3a), so that when the closure (1; 1') is connected to the container (100; 100'; 100"), the gas outlet (25) of the gas delivery channel (22) is arranged inside the container (100; 100'; 100"); as well as A sensor assembly (31) comprising one or more sensors (33) located within at least one sensor access channel (35), the sensor assembly being arranged in the closure such that when the closure is connected to the container, the one or more sensors (33) are disposed inside the container, the at least one sensor access channel (35) being connected to the impeller shaft (13).
2. The closure according to claim 1, wherein: The impeller shaft (13) is telescopic, thereby the length of the impeller shaft (13) can be adjusted.
3. The closure according to claim 2, wherein: The impeller shaft (13) comprises: a hollow outer shaft (13a), the hollow outer shaft (13a) being connected to the inner surface (3a) of the closure (1; 1'); and an inner shaft (13b), the inner shaft (13b) being telescopically arranged inside the hollow outer shaft (13a) so that it can protrude from the hollow outer shaft (13a) to different lengths, wherein the inner shaft (13b) is connected to the impeller blades (15), and wherein the inner shaft (13b) is mounted on the hollow outer shaft (13a) so that it can rotate around the longitudinal center axis A of the impeller shaft (13).
4. A closure according to any one of the preceding claims, wherein: The gas delivery channel (27) of the gas delivery device (21) is arranged inside the impeller device (11).
5. The closure according to claim 5, wherein: The sensor access channel (35) is arranged in the closure (1; 1') so that it extends from the outer surface (3b) of the closure (1; 1') to the inner surface (3a) of the closure (1; 1') and protrudes from the inner surface (3a) of the closure (1; 1'), and wherein the one or more sensors (33) are arranged in the sensor access channel (35) so that when the closure (1; 1') is connected to the container (100; 100'; 100"), the sensor (33) can be used to measure characteristics of the contents provided in the bioreactor (200; 200'; 200"), and so that the one or more sensors (33) can be approached from the outer surface (3b) of the closure (1; 1') via the sensor access channel (35).
6. The closure according to claim 5, wherein: The one or more sensors (33) include a pH sensor and / or a DO sensor, and wherein the sensor (33) is an optical sensor and / or a chemical electrical sensor.
7. A closure according to any one of the preceding claims, wherein: The gas inlet (23) is configured to be connected to an external gas source.
8. A closure according to any one of the preceding claims, wherein: The impeller means (11) comprises a magnetic portion (17) for allowing magnetic actuation to rotate the impeller means (11) from outside the container when the closure (1; 1') is connected to the container (100; 100'; 100").
9. A closure according to any one of the preceding claims, wherein: The closure (1; 1') further comprises fixing means (41) for fixing the closure to the container (100; 100'; 100").
10. A closure according to any preceding claim, wherein: The closure (1; 1') is configured to be connected to a container (100; 100'; 100") which is a bottle.
11. A closure according to any one of the preceding claims, wherein: The closure (1; 1') is configured to be connected to a container (100; 100'; 100") having an internal volume between 50 mL and 2 L.
12. A bioreactor (200; 200'; 200") comprising a closure (1; 1') according to any one of the preceding claims and a container (100; 100'; 100") connected to each other.
13. A method for converting a container (100; 100'; 100") into a bioreactor (200; 200'; 200"), the method comprising the following steps: A closure (1; 1') according to any one of claims 1-12 is attached (S1) to the container (100; 100'; 100"), thereby providing a bioreactor (200; 200'; 200").
14. The method according to claim 13, further comprising the steps of: The length of the impeller shaft (13) is adjusted (S2) according to the size of the container (100; 100'; 100").