Cord Blood-Derived Hematopoietic Stem/Progenitor Cells: Current Challenges in Engraftment, Infection, and Ex Vivo Expansion

Table 1

Summary of culture supplements used for expansion.

Supplements	Advantages	Disadvantages
Flt3/Flk2 ligand	Popularly used in numerous studies; serum-free conditions available	Expensive for large-scale culture; difficult to determine the molecular mechanisms of the action; too many combinations, which are not standardized; some ILs may not be necessary
Stem cell factor
ILs
Thrombopoietin
Feeder cell	No need to supply expensive growth factors	Complicated culture systems
Notch ligand	Effective; signaling pathway is relatively clear	Immobilization required; could induce apoptosis under certain conditions
Aryl hydrocarbon receptor antagonists	Defined chemicals, can reduce the cost	Very new, further studies needed