Investigating limitations during process development at reduced perfusion rates

BIOT 155

Hans Drouin1, Stéphane Lanthier2, Amine Kamen2, James M. Piret, jpiret@chml.ubc.ca1, and Yves Durocher2. (1) Michael Smith Laboratories & Department of Chemical and Biological Engineering, University of British Columbia, 2185 East Mall, Vancouer, BC V6T 1Z4, Canada, (2) Technologie des cellules animales, CNRC - Institut de Recherche en Biotechnologie, 6100 Royalmount Av, Montreal, QC H4P2R2, Canada
To increase perfusion culture product titres the strategy of operation at decreased dilution rates with fortified media was explored. HEK293 cells producing interferon-α2b were cultivated in perfusion mode until the system reached a steady state at 5.3 x 106 viable cells/mL with a specific productivity of 26 pg/cell-day. The dilution rate was then decreased every 5 days while the feed was enriched to maintain the nutrient feed rate. However, the cell specific rates decreased such that the product titre did not increase. Batches cultivated in fresh medium, spent medium (harvested during perfusion) and nutrient-enriched spent medium were compared to identify the major limitation between metabolite accumulation and nutrient depletion on the growth rate and productivity. Specific growth rates were 25% lower with spent medium cultures indicating a predominant growth inhibition effect that should explain the decreased productivity during the perfusion culture. Dilution rate should be reduced according to inhibition level while bleed rate maximized for growth sensitive cells.
 

Upstream Processing: Advances in Cell Culture Process Development
3:00 PM-5:25 PM, Tuesday, August 21, 2007 BCEC -- 107A, Oral

Division of Biochemical Technology

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007