A REVIEW OF THE EFFECTS OF SHEAR AND INTERFACIAL PHENOMENA ON CELL VIABILITY

The shear sensitivity of animal and plant cells is a problem often enc ountered in large-scale cell culture. Such sensitivity varies with dif ferent cell lines and the severity of cellular damage may depend on bo th the magnitude and the duration of the shear stress. In a bioreactor , the shear susceptibility of cells depends on their response to hydro dynamic forces arising from fluid motions of particular scale. Cell da mage may be induced by forces in the bulk liquid phase, but fluid moti ons associated with the gas-liquid interface are especially energetic. The detrimental effects of hydrodynamic forces are abated by the addi tion of some polymers, such as Pluronic F-68, methylcellulose, or seru m; the exact mechanisms of protection are the subject of current resea rch.