IMPELLER-FREE AGITATOR FOR SUSPENSION CULTURE OF MAMMALIAN CELLS.
An impeller-free mechanism for suspension and agitation of mammalian cells or cell-covered microcarrier beads is described. The approach involves the controlled, large-amplitude deformation of a compliant portion of the bioreactor boundary. The deformable section, an elastomeric membrane, forms the bottom of a cylindrical reactor vessel. Cyclic pressure variations in a chamber below the membrane drive it smoothly between a flat and an inflated, concave configuration. The unsteady flow that develops within the reactor exhibits a primary vertical current capable of maintaining a suspension of microcarrier beads, as well as smaller-scale turbulence that could enhance the transport of dissolved oxygen. A small model reactor is described and a numerical simulation of the flow during a membrane deformation stroke is presented.
