There are primarily two types of perfusion systems defined by the relative relation between the construct and media flow: transverse flow (i.e., media flow through the construct) and parallel flow (i.e., media perfuse on the surface of the construct). The results from these two types of the perfusion bioreactor systems vary significantly and no direct comparison is yet available. We are currently evaluating the effects of two operational modes on hMSC construct development by operating two chambers in transverse flow and the other two under parallel flow within the same system of four flow chambers. Preliminary results showed that parallel flow mode has higher cell and CFU-F numbers than that of the transverse flow over a 20-day culture period. Taken together, these results demonstrate that shear stress is a significant regulator for 3-D hMSC construct development and that bioreactor configuration is an important consideration for designing the perfusion bioreactor system.
1. Zhao F, Chella R and Ma T. Effects of shear stress on 3-D human mesenchymal stem cell construct development in a versatile perfusion bioreactor system: experiments and hydrodynamic modeling. Biotechnology and Bioengineering, in review.
2. Zhao F, and Ma T. Perfusion bioreactor system for human mesenchymal stem cell tissue engineering: dynamic cell seeding and constructs development. Biotechnol Bioeng 2005;91:482-493.
3. Zhao F, Pathi P, Grayson WL, Xing Q, Locke BR, and Ma T. Effects of oxygen transport on 3-D human mesenchymal stem cell metabolic activity in perfusion and static cultures: experiments and mathematical model. Biotechnol Prog, 2005;21:1269-1280.