| abstract |
The present invention includes a bioreactor support system that provides an improved way to culture large quantities of mammalian cells. Mammalian cells are extremely sensitive to their environment, undergoing a programmed cell death in response to nutrient deprivation, growth factor withdrawal, oxygen starvation and excess shear levels. The present invention includes a bioreactor support system which permits the culture of cells at high density and prevents cell death by providing enhanced oxygen delivery to the cells without excessive shear; maintaining cell secreted or exogenously added low molecular weight products (e.g., growth, differentiation and maintenance factors) in the culture space during perfusion culture; and provides the ability to feed the cultures without dilution of the conditioned media. The improved bioreactor support system features two flow paths emanating from a central integrating chamber. The first flow path is a slow speed loop from a bioreactor containing a cell retention module and a return line for cells. Cell-free media from the cell retention module enters the integrating chamber. The second flow path is a high speed loop containing an oxygenation module and a dialysis module. The return line from the integrating chamber to the bioreactor is a rate controlled perfusion system containing oxygen-saturated, pH adjusted, nutrient-rich, metabolic waste depleted, conditioned media. The support system can be used to enhance the growth and maintenance of mammalian cells in a variety of bioreactor configurations, including fermentors, spinner flasks, flexible bags, rotational devices and hollow fibers. |