| 摘要 |
<p>The present invention provides methods and bioreactors for expanding stem cells in a population of cells substantially enriched in hematopoietic stem cells and substantially free of stromal cells. The method preferably comprises the steps of inoculating the population of cells in an expansion container in a volume of suitable medium such that the cell density is at least about 5,000 cells/1 mL and at an initial oxygen concentration of less than 8 %; adding an effective amount of at least one cytokine to cause stem cell expansion; culturing the cells under suitable conditions such that the cells condition the medium; increasing the oxygen concentration to about 20 %; exchanging the medium at a rate which allows expansion of the stem cells; and culturing the cells under conditions such that the stem cells are expanded. The present invention also provides a bioreactor constructed to accommodate the operational requirements for stroma-free stem cell expansion.</p> |
