STRATEGIES FOR DEVELOPMENT OF CULTURE MEDIA: APPLICATION TO EMBRYONIC AND ADULT STEM CELLS

摘要

Both exploratory research and proposed clinical applications of human stem cells and derived cell populations demand refinements in the nutrient environment. Significant early research has been performed with serum supplementation, using FBS lots thatwere carefully selected for performance characteristics based on expansion and maintenance of the undifferentiated phenotype. However, the ill-defined composition and lotto-lot variability in proliferation and differentiation factors inherent to serum and potential foreign protein immunogenicity and adventitious agent contamination make serum unattractive for these applications. This laboratory continues to refine its approach to develop serum-free specialty nutrient formulations for targeted expansionand differentiation of adult and embryonic stem cell populations. Modifications of AIM-V Medium, originally developed for lymphokine activated killer (LAK) cell adoptive immunotherapy, may be modified for studies in T cell-mediated therapy and dendriticcell applications. KnockOut~(R) formulation modifications and serum replacements have reduced variability in embryonic stem cell expansion and differentiation studies, facilitated isolation of novel stem cell lines and permitted feeder-free cultivationunder some limited conditions. Neurobasal~(R) media and specialized supplements (e.g., B27 modifications) have enhanced neurosphere formation, increased the number of neurospheres, and supported the ability to generate differentiated CNS cell types. Where total serum replacement has been technically challenging to date, such as the three-dimensional cultivation of neurospheres or mesenchymal stem cell populations, several modifications of Advanced Media have permitted substantial reduction in serum requirement to yield differentiated tissue phenotypes.