Bone Marrow-Like Bioreactor

Detroit, Michigan -

The ex vivo expansion of hematopoietic stem cells in large numbers would allow for numerous autologous transplant approaches to become a clinical reality. For example, one could hypothetically expand and keep frozen their own stem cells for when they need them later in life. Unfortunately, many attempts at expanding CD34 hematopoietic stem cells have failed to either expand number, or numbers of CD34s are expanded but activity is lost.

In a recent paper (Cho et al. Application of porous glycosaminoglycan-based scaffolds for expansion of human cord blood stem cells in perfusion culture. J Biomed Mater Res A. 2007 Oct 16) investigators developed a three-dimensional bioreactor meant to mimic the bone marrow microenvironment.

A porous heparin-chitosan scaffold approach was taken in which cord blood CD34 cells were seeded and expanded for 7 days in the presence of continuous perfusion or non-perfusion. By the way, chitosan is produced commercially by deacetylation of chitin , which is the structural element in the exoskeleton of crustaceans (crabs, shrimp, etc).

The authors demonstrated increase in CD34 counts, as well as colony forming units when cells were grown under perfusion conditions. Additionally, the authors were able to enhance yeild by growing the cells under hypoxic conditions.