A method of expanding/maintaining undifferentiated hemopoietic stem cells or
progenitor
cells by obtaining undifferentiated hemopoietic stem cells or progenitor cells;
and either seeding the undifferentiated hemopoietic stem cells or progenitor cells
into a stationary phase plug-flow bioreactor in which a three-dimensional stromal
cell culture has been pre-established on a substrate in the form of a sheet, the
substrate including a non-woven fibrous matrix forming a physiologically acceptable
three-dimensional network of fibers, thereby expanding/maintaining undifferentiated
hemopoietic stem cells or progenitor cells, or culturing the undifferentiated hemopoietic
stem cells or progenitor cells in conditioned medium obtained from such a reactor.
