This award will support collaborative research between Dr. Donald Kirwan of the Bioprocess/Product Development Center at the University of Virginia and Professor John M. Smith of the Process Biotechnology Program at the University of Surrey in the United Kingdom. Both of these research groups are investigating improved reactors for animal cell culture. The increased demand for monoclonal antibodies, therapeutic proteins, vaccines, and other high value products of animal cell culture requires that efficient larger scale processing methods be developed. This proposal deals with the initiation of a cooperative research effort between two groups devoted to this activity. The joint research will focus on two topics: 1) The measurement and modeling of shear stress fields in bioreactors and (2) the role of diffusion in influencing the productivity of immobilized animal cells. The first project will involve the investigation of the turbulent shear created by bubble coalesence events in aerated bioreactors. The understanding of shear fields will be directly applicable to the culturing of animal cells. The second project will involve diffusion and reaction of nutrients, oxygen, and cell regulators in animal cell-filled gel particles. The concentrations and time varying patterns of biochemicals can be important to cell productivity. The researchers will model this phenomena based upon data on diffusivities in gels, cell uptake rates, and the influence of regulators in free cell cultures.
