Le. Aloi et Rs. Cherry, CELLULAR-RESPONSE TO AGITATION CHARACTERIZED BY ENERGY-DISSIPATION ATTHE IMPELLER TIP, Chemical Engineering Science, 51(9), 1996, pp. 1523-1529
Sf9 insect cells in suspension show an increase in intracellular calci
um concentration as a function of local energy dissipation rate in two
fluid systems. A significant calcium response (more than a 10% increa
se) resulted at a dissipation rate above 10(7) cm(2) s(-3) in 15 min c
apillary flow experiments. Similar results were obtained after 4h with
a dissipation rate above 10(5) cm(2) s(-3) or in a bioreactor stirred
at greater than or equal to 280 rpm for 4 h with a 6-bladed Rushton i
mpeller. This impeller speed produces a local energy dissipation rate
of 10(5) cm(2) s(-3) if the dissipation rate is estimated using the vo
lume of the trailing vortices as the dissipation volume (V = 0.075d(i)
(3)). Our results show the capillary flow system to be a good model fo
r prediction of cell damage in a stirred bioreactor.