Stem/Progenitor cells from umbilical cord blood (UCB) have many advantages as a source of hematopoietic cells for transplantation. Studies have shown that cord blood cells are an effective alternative to bone marrow for transplantation and lack the HLA restrictions of bone marrow derived cells. Development of cord blood cells for therapy is dependent on the development of successful blood-derived free and xeno-free culture methods that enable the ex vivo expansion of clinical grade cells.

A recent review article by Kita et al. entitled “Cord Blood Derived Hematopoietic Stem/Progenitor Cells: Current Challenges in Engraftment, Infection, and Ex Vivo Expansion” details the current advances and the challenges in the establishment of defined culture conditions for the expansion of cord blood stem cells [1].

“The limited number of human stem cells/human progenitor cells is the major obstacle in blood transplantation. Efficient methods are needed to obtain a larger quantity of primitive cells from umbilical cord blood (UCB). For this reason, developing simple and realistic protocols for the industrial expansion of primitive cells in UCB is essential. …With well-defined ex vivo expansion protocols, UCB is likely to “rock” the area of blood cell transplantation.”

The article further details the advancement of growth factor cocktails (notch signaling ligand) and alternative approaches (such as the use of aryl hydrocarbon receptor antagonists) that may advance the efficient ex vivo expansion of these cells. Other advances, such as the use of defined, recombinant, xeno-free, blood-free culture medium components, such as transferrin and human albumin (2), further enable the development of the defined clinical protocols required for clinical application.