Fluid-Mechanical Damage of Freely-Suspended Animal Cells in Agitated Bioreactors: Effects of Dextran, Derivatized Celluloses and Polyvinyl Alcohol

Different media additives were used to analyze cell damage and “shear protection” characteristics of freely suspended animal cells (CRL-8018) cultured in stirred tank bioreactors. The additives used included dextran, polyvinyl alcohol (PVA), and methylcellulose, which are viscosity enhancers, surface active agents or combinations of these, respectively. We used these additives to study the effects of bulk viscosity and interfacial properties on cell damage or protection under conditions whereby bubble-induced cell damage becomes inhibitory to cell growth if the medium is not supplemented with a protective additive. Dextran (229 kDa, 1–3% w/v) was used to analyze the effects of increased bulk viscosity on cell damage or protection. It was found that the presence of dextran increased cell death under intense agitation. Several grades and types of derivatized methylcelluloses including Methocel A15LV (15 kDa, 0.1–0.5 w/v%), Methocel E50LV (50 kDa, 0.1% w/v), and Methocel H100LV (100 kDa, 0.25% w/v),...