September 15, 2009 (Vol. 29, No. 16)
Wu Ma, Ph.D., at the ATCC and his colleagues at the NIH and the Naval Research Laboratory recently succeeded in creating a 3-D, functioning cerebral cortex model from rat embryonic neural stem/progenitor cells (Tissue Engineering, Part A, Vol. 14, No. 10). The cells were immobilized in collagen gels and cultured in the NASA rotating wall vessel (RWV) bioreactor manufactured by Synthecon called the Rotary Cell Culture System.
The use of cells immobilized in natural or artificial matrices to enable 3-D culture has become widespread. This approach, however, has been hindered by the limitation of nutrient and oxygen transport in static culture.
“The addition of the dynamic RWV culture system has dramatically improved the outcome of 3-D culture as demonstrated in this paper,” says Stephen Navran, Ph.D., CSO at Synthecon. “For example, in the static neuronal 3-D culture, the cells were viable for only about 2–3 weeks, whereas the RWV cultures could be maintained for at least 10 weeks.”
During this period, the RWV cultures developed a complex two-layer structure resembling an embryonic cerebral cortex. The cells in the surface layer expressed a neural progenitor phenotype while cells in the deeper layer expressed a differentiated neural and astrocyte phenotype. Cells in each layer expressed different functional neurotransmitter receptors as well.
“This tissue-engineered neural construct has the potential to be used for drug development and regenerative medicine applications,” noted Dr. Navran.