Kinetic Analysis of the ex vivo Expansion of Human Hematopoietic Stem/Progenitor Cells

The total cell expansion of human umbilical cord blood (CB) and adult bone marrow (BM) CD34+-enriched cells cultured in supplemented serum-free media, either over irradiated human feeder layers or in stroma-free systems, were characterized by a simple kinetic model using only two parameters: the specific cell expansion rate, μ, and the death rate constant, kk. Both CB and BM cells can expand at approximately the same rate (0.21 day−1) in this culture system however, cell death depends on the presence of stroma and the environment in which the cells are cultured.