Abstract:
A multi-chamber cell culture assembly has provisions for the distribution of nutrient culture medium and gasses throughout each of the chambers. A device is constructed to provide a large surface area for the growth and cultivation of hybridomas, mammalian and insect cells. The device may incorporate macro, micro or nano structures on the growth surfaces to promote or enhance distribution of nutrients, cell product, gasses or growth area. Cell growth, nutrient addition and cell product withdrawal may be carried out automatically.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application claims the benefit of the filing date of U.S. Provisional Application Ser. No. 60/758,016, filed Jan. 11, 2006, the teachings of which are incorporated herein by reference. 
    
    
     FIELD OF INVENTION 
     The present invention relates to a method and apparatus for the culture of cells. 
     BACKGROUND 
     Cell cultures provide for the growth and maintenance of a cell or cells in favorable conditions. Cells may include hybridomas, stem, mammalian and insect cells, among others. To grow and maintain the cells, cell nutrients, cell products and gasses may be provided to a culture. 
     SUMMARY 
     An exemplary aspect of the present invention relates to a cell growth chamber, the interior surfaces of which are adapted for the growth of cells and defining a culture space. An inlet may be defined in the cell growth chamber for providing fluid and gasses to the culture space and an outlet may be defined in the cell growth chamber for collecting the fluid and gasses from the culture space. The interior surfaces of the cell growth chamber may form a channel that is defined by a wall and a base located between said inlet and outlet. 
     One aspect of the present invention provides a cell culture device in which cells may be grown to a high density in a self contained apparatus. 
     Another aspect of the present invention provides a cell culture assembly having a plurality of growth chambers, wherein in each growth chamber may have a substantially equal distribution of nutrient medium and gasses. 
     Another aspect of the present invention provides a cell culture assembly that may allow for the continuous addition of nutrient medium and gasses and the removal of conditioned nutrient medium, gasses and products formed by the cells. 
     Another aspect of the present invention provides a flow system which may be continuous and may promote an optimal environment for the production of biochemicals, viral vaccines, antibodies and other pharmaceuticals. 
     Another aspect of the present invention provides a cell culture assembly that may be a self-contained device. 
     Another aspect of the present invention provides a cell culture assembly that may contain a variety of macro, micro and or nano structures, which may support or enhance the growth and attachment of cells and production of bio-chemicals. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The detailed description below may be better understood with reference to the accompanying figures which are provided for illustrative purposes and are not to be considered as limiting any aspect of the invention. 
         FIG. 1  is a perspective view of an exemplary embodiment of an assembly. 
         FIG. 2  is a cross sectional side view of an exemplary embodiment of an assembly. 
         FIG. 3  is a perspective view of an exemplary plate of the assembly. 
         FIG. 4  is a perspective view of an exemplary array of plates sectioned to reveal the construction of the assembly. 
         FIG. 5  is a perspective view of an exploded section of the structured surface of an exemplary growth area. 
         FIG. 6  is perspective view with section cut away to reveal an exemplary embodiment of interchamber fluid dams and fluid path. 
         FIG. 7  is a schematic view of an embodiment of the invention incorporated into a continuous culture system. 
         FIG. 8  is a perspective view of an exemplary plate of a rectangular embodiment of the invention. 
         FIG. 9  is a perspective view of an exemplary plate of another rectangular embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention may provide a culturing environment, which may be continuous, in a device having a plurality of growth chambers, stacked in an array, creating a large surface area for the culture of cells at high density, interspaced with a large surface area of nutrient medium exposed to the culture gasses. The device may be constructed and arranged to permit the directional flow of nutrient medium throughout each of the growth chambers. The flow may be adequate to provide for the gentle mixing of the nutrients throughout the entire growth area of the device, while at the same time providing adequate mixing with the culture gasses to assure that proper oxygenation and gas concentration may be maintained for the growth of cells. 
     Preferably, the culture device may include an array of culture chambers defined by the spaces between the superpositioning of a plurality of stacked plates. An inlet conduit may be provided for the nutrient medium. An inlet conduit may be provided for the introduction of culture gasses. The nutrient medium and the culture gasses may flow together throughout the culture chamber providing a distributed flow of nutrients mixed with the culture gasses throughout the entire growth chamber and each chamber may be serially connected to the next growth chamber. The growth surfaces of each of the culture chambers, may be altered by a variety of macro, micro or nano structures as required to effect the desired culture density or the proper distribution of gasified nutrient medium to either the basal or lateral surfaces of the cells being cultured. 
     The cell culture device of an exemplary embodiment may include an array of culture chambers enclosed within a vessel. The vessel may also incorporate a reservoir for the culture media and gasses. The exterior view, illustrated in  FIG. 1 , shows an exemplary embodiment of a vessel  10 . The vessel  10  may be substantially cylindrical. The vessel  10  may incorporate as illustrated in  FIG. 2  a molded top  28 ; a molded bottom reservoir  26  and culture chambers  20 . The top  28 , culture chambers  20 , and bottom vessel  26 , may be molded together or sealed to provide a fluid-tight arrangement for the culture chambers. 
     Referring back to  FIG. 1 , the vessel  10  may include three conduits extending from the top of the vessel  10 ; a fluid inlet conduit  11 , a gas inlet conduit  13  and a gas outlet conduit  14 . The bottom of the vessel may also contain two conduits, the fluid outlet conduit  12  and the product/waste conduit  15 . Fluid may enter the vessel  10  through inlet conduit  11  and may flow gently down a fluid path of the first culture chamber  20 . The fluid may form a stream of continuously moving and mixing fluid that may communicate with the cultured cells and may provide a continuous source of nutrients and gasses. 
     An exemplary embodiment of a single culture chamber is illustrated in  FIG. 3 . The fluid stream may enter the culture chamber at inlet  11  and flow down the sloped inlet path  32 , moving through the structured culture chamber  20 , and arriving at the outlet conduit  22  of the first culture chamber. The gas mixture may enter the first chamber from the gas inlet  13  and may then move throughout the entire culture chamber arriving at outlet  22 . 
     A fluid dam  31 , illustrated in  FIG. 6 , may be provided as a means to establish the depth of the fluid stream and may surround each outlet conduit  22 . The depth of the fluid stream, may be varied to enhance the flow and mixing to the structured culture surface. The fluid may flow over the dam  31 , and gently through the inlet conduit  21  and down the sloped inlet path  32  of inlet  21  of the next culture chamber  FIG. 6 . The gas dam  35 , also illustrated in  FIG. 6 , may prevent the flow of fluids through a section of each outlet  22 . The gasses may flow over the gas dam  35  through the inlet  21  of the next culture chamber. Each culture chamber  20  may contain a fluid dam  31  and a gas dam  35  located at the outlet of the culture chamber  22  and may include a sloped inlet path  32  located at the inlet  21  of the next culture chamber. The fluid path may repeat this process until it reaches the final outlet conduit  22  over the molded bottom reservoir  26 , illustrated in  FIG. 2 . The fluid may flow gently down the reservoir inlet path  29  and may be collected in the reservoir  26 . 
     The outlet conduits  12  and  15  may extend through the top of the assembly rather than through the base as shown in  FIG. 2 . Referring to  FIG. 3 , an exemplary culture chamber  20  of the array is depicted with the inlet conduit  21  covered to allow the flow of fluid to move axially towards the center of chamber  20  and over dam  31  of outlet conduit  22 . The chamber  20  also affords a passage  24  for the egress of culture gasses collected and delivered to gas outlet conduit  14 , illustrated in  FIG. 1 . Waste gasses that may be collected in the head space of the reservoir, may be collected and delivered via gas conduit  24  to the exit conduit  14 , illustrated in  FIG. 1 . 
     A large surface area of culture chambers may be provided by the superpositioning of culture chambers  20 . Referring to  FIG. 4 , the section removed reveals culture spaces  25  formed by the superpositioning of chambers  20  in an array. Fluids retained in the culture chambers  20  may cover the culture surfaces  25 . Referring to  FIG. 5 , the culture surfaces may be structured  29 , illustrated in inset, to form either macro, micro or nano structures which may enhance the communication or distribution of nutrients or attachment sights within the culture chambers. 
     The exemplary embodiment discussed above is a cylindrical culture chamber device that combines certain fluid/gas delivery and mixing conditions. The embodiment discussed above may incorporate uniquely designed fluid/air dams, and sloped inlet structures to enhance the delivery of fluid medium and gasses to each of the culture chambers. The fluid dams and sloped inlets may deliver gentle, low shear, fluid to the culture chambers. The low shear mixing may be desirous for the culture of cells and many of the biochemicals and proteins that may be subject to degradation caused by shear or denaturizing. However is will be understood by one skilled in the art, that other configurations may be constructed to achieve the same effects of mixing. Referring to  FIGS. 8 and 9 , the culture chambers  20  are illustrated with two different placements of the fluid inlet and outlet ports  11  and  12 . 
     In another exemplary embodiment, the chambers may be molded to form a structure that is self-contained and fluid tight. The structure may be rendered fluid tight via sealing, molding or welding the chambers together. It should also be appreciated however that it may be desirable to separate the chambers to harvest the cells or products therein. Accordingly, the chamber may be designed to seal upon superimposing the cell growth chambers. 
     According to one aspect of the invention, the cell culture device  10  may be provided as part of an assembly  100  as depicted schematically in reference to  FIG. 7 . The assembly  100  may be constructed and arranged for continuous operation. The assembly  100  may be a closed loop system connecting the culture vessel  10  of the invention into a continuous culture system. 
     The fluid collected in reservoir  26  may be delivered via the fluid outlet conduit  12  to conduit  50  and to pump  60 . The pump  60  may move the fluid through conduit  51  to the fluid inlet conduit  11 . Fresh nutrients may be added via pump  70  and conduit  52  to the fluid circulation in conduit  51 . Excess nutrients-products/waste, may be collected by pump  71  via conduit  53  to maintain a constant volume of fluid within the vessel  10 . Optional sensors  92  may be employed to monitor the system. The sensors  92  may be connected to a control means  90 . The control means may have the ability to monitor or control the mixture of gasses delivered via conduit  54  to the gas inlet conduit  13  by controlling the gas mixture of gasses  80 ,  81  and  82  at valves  95 ,  96  and  97 . The control means may have the ability to control the fluid input  70  and output  71  pumps and the circulation pump  60 . 
     It should be understood that various changes and modifications of the embodiments described may be made within the scope of the invention. The foregoing description is provided to illustrate and explain the present invention. However, the description hereinabove should not be considered to limit the scope of the invention set forth in the claims appended here to.