Bioreactor Based Production of Functional Conditioned Medium for the Propagation of Undifferentiated Human Embryonic Stem Cells

Abstract

Embryonic stem (ES) cells are characterized by their capacity for self-renewal and their pluripotency. A crucial prerequisite for a therapeutic use of human ES cells is the ability to expand them to large numbers without affecting their pluripotency. For many murine ES cell lines, leukaemia inhibitory factor suffices to prevent spontaneous differentiation. In contrast, the human ES cell lines available depend on feeder cells, i.e., coculture with mitotically inactivated mouse embryonic fibroblasts (MEFs) or treatment with conditioned medium (CM) derived from such cultures. This dependency on feeder cells is associated with batch-to-batch variations, difficulties in implementing large scale suspension culture of ES cells and potential carryover of pathogens from the feeder to the ES cell population