Performance of small-scale CHO perfusion cultures using an acoustic cell filtration device for cell retention: Characterization of separation efficiency and impact of perfusion on product quality

Abstract

Several small‐scale Chinese hamster ovary (CHO) suspension cultures were grown in perfusion mode using a new acoustic filtration system. The separation performance was evaluated at different cell concentrations and perfusion rates for two different CHO cell lines. It was found that the separation performance depends inversely on the cell concentration and perfusion rate. High media flow rates as well as high cell concentrations resulted in a significant drop in the separation performance, which limited the maximal cell concentration achievable. However, packed cell volumes of 10% to 16% (corresponding to 3 to 6 · 107 cells/mL) could be reached and were maintained without additional bleeding after shifting the temperature to 33°C. Perfusion, up to 50 days, did not harm the cells and did not result in a loss of performance of the acoustic filter as often seen with other perfusion systems. Volumetric productivities in perfusion mode were 2‐ to 12‐fold higher for two cell lines producing two different glycoproteins when compared to fed‐batch or batch processes using the same cell lines. Product concentrations were in the range of 20% to 80% of batch or fed‐batch culture, respectively. In addition, using the protease‐sensitive product rhesus thrombopoietin, we could show that cultivation in perfusion mode drastically reduced proteolysis when compared to a batch culture without addition of protease inhibitors such as leupeptin. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 69: 440–449, 2000.

Fractionation of cell mixtures using acoustic and laminar flow fields

“…Numerous works in the literature have shown that short-term exposure of cells to the levels of sound intensity used here do not have detrimental effects on cell viability (Gaida et al, 1996;Ryll et al, 2000;Wang et al, 2003). Improvement in the fractionation can be expected by opti mization of the operating parameters and chamber geom etry.…”

Proliferation control strategies to improve productivity and survival during CHO based production culture

“…Therefore although the effects of low culture temperature on the cellular productivity of recombinant proteins are variable and depend on the temperature, cell line, clone, expression system and/or protein, the effect of reducing cell growth is a universal phenomenon Ohsuye 1998, 1999;Kaufmann et al 1999;Ryll et al 2000;Schatz et al 2003;Yoon et al 2003aYoon et al , b, 2004Yoon et al , 2006Fox et al 2004;Fogolin et al 2004, Bollati-Fogolin et al 2005Trummer et al 2006;Al-Fageeh et al 2006). …”

Significances of pH and temperature on the production of heat-shock protein glycoprotein 96 by MethA tumor cell suspension culture in stirred-tank bioreactors

“…Unlike the case of specific growth rate, effects of lowering culture temperature on specific productivity may not be generalized. In many reports, the specific productivity of hybridoma, BHK, and CHO cells was not enhanced by lowering of the culture temperature [26,33,38,39,42,43]. On the other hand, there are few reports that the specific productivity of CHO cells increased at low temperature [37,44].…”