Patent Application
20210016287
The present invention relates to a novel bioprocess bag for cell cultivation having reinforced internal structures. More specifically, the invention relates to an improved bioprocess bag and related structures, including reinforced and improved tube features.
Cell therapy is a new but rapidly expanding field in biotechnology which involves the administration of autologous or allogeneic cells that carry out a therapeutic effect in vivo. Cell therapy involves a number of mandatory stages from cell collection to cell injection into a patient. Cell culturing for cell therapy is carried out in clean room environment. Cell culturing and clean rooms has many mandatory regulations like particle size and count in clean room, number of patient samples handled at a time, and number of instruments per suite, as well as a requirement for a sterile environment etc.
Earlier systems for cell culture were stand alone, required large space and could not handle multiple patient samples at same time. Procedures for cell culturing for cell therapy involve a lot of human intervention, which may contaminate cell cultures and damage cell growth, especially small size cell cultures.
Disposable bioreactor or fermenter bags have been developed for cell therapy. The use of disposable bioreactor bags in cell culture reduces batch changeover times by eliminating time consuming cleaning and equipment validation, resulting in higher throughput.
Also shown in
For systems including multiple spargers, control system 134 may be operatively associated with each of the spargers and configured to operate the spargers independently of each other. Support structure 114 and/or container 118 may also include, in some embodiments, one or more ports 154 that can be used for sampling, analyzing (e.g., determining pH and/or amount of dissolved gases in the liquid), or for other purposes. These ports may be aligned with one or more access ports 156 of optional environmental containment enclosure 120.
Apparatus 100 may include, in some embodiments, one or more connection ports 180 for interconnecting an interior of reusable support structure 114 (e.g., gap 132) to an interior of a second apparatus. Additionally or alternatively, the apparatus may include one or more connection ports 182 adapted for connecting an interior of container 118 (e.g., interior 56) to an interior of an interior of the second apparatus. These ports can facilitate transfer of a material from interior 56 to the second apparatus or to another suitable container (e.g., a sealed bag). Transfer may be accomplished, for example, by pumping the material through tubing (e.g., by peristaltic pumping or by applying a positive pressure to an inlet), by use of gravity, and/or by application of a vacuum.
Apparatus 100 may optionally include a mixing system such as an impeller 151 positioned within container 118, which can be rotated (e.g., about a single axis) using a motor 152 that may be external (or internal) to the container. The mixing system can be controlled by control system 134. Optionally, the container and/or support structure may include a utility tower 150, which may be provided to facilitate interconnection of one or more devices internal to the container and/or support structure with one or more pumps, controllers, and/or electronics (e.g., sensor electronics, electronic interfaces, and pressurized gas controllers) or other devices. Such devices may be controlled using a control system 134.
Integral with the bioreactor may be one portion of the mixing system. Specifically, as shown in
The bag 1 may be pivotally mounted to a base 9 about a movable axis 7 generally parallel to the end edges 4. The movable axis 7 may be located below the bag 1 and the bag may be mounted on a support 8, e.g. with the distance between each edge 4 to the projection of the movable axis 7 on the bottom sheet 3 being approximately equal to D/2. Suitable pivotable supports mounted on a movable axis can be e.g. the WAVE Bioreactor™ Systems (GE Healthcare). The flexible material of the top 2 and bottom 3 sheets may be a polymeric material, such as a plastic film or laminate with a thickness e.g. in the 50-500 micron range. A laminate may in addition to one or more polymeric materials comprise e.g. bather layers, which may be polymers or inorganic oxides or metals. The top sheet 2 in particular can be transparent to ensure visibility into the bag. The top sheet 2 and the bottom sheet 3 are defined with respect to the positions during use of the bag, i.e. in use the top sheet 2 is located above the bottom sheet 3. The top and bottom sheets may also be distinguished in that the ports 11 are preferably located on the top sheet 2, providing a smooth outer surface of the bottom sheet 3, suitable for resting on the support 8. The side edges 5 may be longer than the end edges 4.
An advantage of the central location of the baffles 6 is that when the bag is partially filled with a cell suspension, inflated and rocking around the axis 7, essentially all the cell suspension will repeatedly pass by the baffles. This increases the agitation intensity and improves the gas exchange in the air-liquid interface, while the agitation is still mild enough not to cause any damage to the delicate cells.
In some embodiments, at least one of the baffles 6, such as two baffles, is/are tubular. One advantage of this is that the baffles can be made flexible enough to allow for easy packing and storage of the collapsed bags before use, but rigid enough to sustain the hydrodynamic forces during operation of the bag. A further advantage is that the tubular structure allows for transport of materials through the baffle into or out of the bag. Tubular baffles can e.g. be prepared from elastomeric materials that allow collapse of the structure during packing of the bag but are resilient enough to give complete recovery of the open tubular shape when the bag is filled and/or inflated. The elastomeric material can e.g. be a cross-linked silicone rubber or other vulcanized rubber material. If tubing with thick walls and/or high rigidity is used, the tubular baffles may also act as columns, keeping the top and bottom sheets of the bag separated before and during inflation of the bag.
A need remains for improved bioreactor or fermenter bags that are capable of withstanding sterilization, packaging, shipping, setup, and use.
The present invention includes aspects relating to an improved bioprocess bag and related structures, including reinforced and improved tube features. In one aspect, the invention relates to an improved bioprocess bag including a bag wall defining an enclosed volume for holding biomaterials, the bag wall comprising at least one inlet port and at least one outlet port; and a tube structure comprising a first opened-end proximate the bag wall and a second distal end, the tube extending into the enclosed volume, and the tube structure comprising a reinforced portion proximate the first opened-end. The reinforced section may include a pattern of sections that are raised relative to the tube outer surface, and the raised sections contacting each other when the tube structure is bent. The contact may prevent crimping of the tube structure during shipping, setup or operation.
In another aspect, the invention relates to a bioprocess bag including a bag wall defining an enclosed volume for holding biomaterials, the bag wall comprising at least one inlet port and at least one outlet port; and a tube structure comprising a first opened-end proximate the bag wall and a second closed-end distal to the bag wall, the tube extending into the enclosed volume, the tube structure comprising a predominantly cylindrical inner wall and a notch that extends at least a portion of the length of the inner wall, wherein the notch defines a channel that allows air to flow out when a probe is inserted into the tube structure.
These aspects of bioprocess bags may include other features used in mixers, bioreactors, and other relevant applications. Those features may include impellers, heaters, and gas outlets. The tube structure may be adapted to accept a probe, such as a thermocouple. Alternatively, or in addition, the tube structure may be adapted to accept a sparging wand. It is contemplated that any number of tube structures according to embodiments of the present invention may be used together, or in combination with other tube structure in a single bioprocess bag. The tube structure may include a predominantly cylindrical inner wall, and a notch extending at least a portion of the length of the inner wall. The notch can be adapted to define a channel that allows air to flow out when a probe is inserted into the tube structure.
In one aspect, the invention includes a reinforced probe housing, the probe housing comprising; a tip portion having a first outer diameter and an first inner diameter defining a thickness, the inner diameter adapted to accept a probe, the probe housing having a closed-end proximate the tip portion; a reinforced portion sharing the same inner diameter as the tip portion, wherein the outside diameter of the reinforced portion includes raised sections that provide reinforcement through contact with one another when the probe housing is bent, the probe housing having an opened-end proximate the reinforced portion, the opened-end adapted to accept the probe. The reinforced probe housing can be included with a bioprocess bag or used independently. The probe housing may be adapted to receive a thermocouple.
The present inventors have found that several of the internal structures of a bioreactor or fermenter bag are susceptible to damage or perceived damage as a result of sterilization and packaging, and further damage to these elements can occur during shipping, setup, or use. The sterilization of the bag with gamma irradiation can in some cases exacerbate the problem by fusing adjacent pieces of material or freezing the material into bent shape. With respect to parts that are internal to the bag, these problems are sometimes compounded by the inability to inspect internal portions of the bag given the need to maintain sterility and not compromise the bag structure. The perception of damage to an internal part may result in the entire bag being deemed unsuitable for use. The tube structure maybe adapted to accept a probe, such as a thermocouple, or a sparging wand. Alternatively, or in addition, the tube structure may be adapted for introducing or withdrawing material from the bioprocess bag.
Those internal bioreactor bag structures most susceptible to this kind of damage or perceived damage are tubular structures. These tubular structures internal to the bag may become bent, crimped, folded at some point in the supply chain.
One particular structure that is susceptible to damage is the thermowell tube found in existing bioreactor bags. One example of such a thermowell is described in U.S. Pat. No. 6,599,012 entitled “Thermowell Adapter,” which is incorporated by reference for its disclosure of thermowell structures. The thermowell tube is a piece of straight tubing made from plastic material that allows insertion of a thermowell into a bioreactor bag without breaching the seal of the bag. Often the thermowell is made from a molded plastic or rubber material. A rigid insert is used to prevent tubing from collapsing and self-sealing internally during gamma irradiation. In some cases the rigid support breaks and can puncture the tubing. Without the support, the tubing kinks and can seal during gamma irradiation. When the temperature sensor is inserted it can puncture the tubing.
In one embodiment shown in
The thermowell tube 400 may also comprise an optional base portion 403 that attaches to a thermowell flange 404, which may be used to form a seal with the bioreactor bag (not shown). Alternatively, the thermowell tube can be directly molded into the bioreactor bag. The base portion provide additional structural support for the thermowell 405 when the thermowell is inserted into the thermowell tube 400.
The reinforced portion 402 may be defined by several geometries in order to accomplish one or more objective of the invention. For example, in one variation, the height 408 of the rib portion 402a may progressively increase in a continuous or stepwise fashion in a direction from the tip portion 401 to the base portion 403. In some cases, the progressive increase in height 408 may result in a more continuous transition from the outer diameter of the tip portion 401 to the base portion 403. Other various reinforcement geometries are within the scope of the invention.
It should be appreciated that reinforced portion 402 described above with respect to a thermowell tube 400 may be applied to any other structure within a bioreactor or fermenter bag. The ribbing structure on the tubing can be applied to other applications on the single-use bioreactor bag where there is potential for the tubing to be kinked and shut down fluid flow. These areas include any internal tubing for fluid transfer, such as the internal sparge tubing or internal dip tubes that deliver fluid directly into the bulk process fluid. This can be used on the top of the bioreactor for the exhaust filter lines as these typical need to be bent in order to be contained and supported within the heaters while still providing a drain path for condensate back to the reactor. Any addition line that is supported and draped over a rigid bar could benefit from a small section of the ribbed tubing where the it is bent. This may prevent fattening of the tube which can cause flow restrictions and high-pressure events. As with the thermowell tube, these portions may be molded directly into the bag or attached to the bag using a flange as was shown with the thermowell above.
It should appreciated that the reinforced tubing structure of the present invention will be particularly useful when added to a single use bioreactor. The ribbing along the tubing, e.g., a molded thermowell tube 400, prevents kinking and self-sealing due to gamma irradiation. When used with a thermowell probe, the temperature sensor portion of the probe is in the ˜1 inch (˜2.54 cm) section at the thermowell tube tip 401 and the thermowell tubing 400 will have a thin wall section to promote fast heat transfer response. An internal channel, or notch 413, will allow air passage during insertion and removal of temperature sensor.
The reinforced tubular structures of the present invention, and particularly the reinforced thermowell tube, may be applied to any disposable bioprocess bag, and particularly those system made of flexible material such as plastics. Any of the disposable bags shown in
Other embodiments and uses of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. All references cited herein, including all U.S. and foreign patents and patent applications, are specifically and entirely hereby incorporated herein by reference. It is intended that the specification and examples be considered exemplary only, with the true scope and spirit of the invention indicated by the following claims.
