Performance of an acoustic settler versus a hollow fiber–based ATF technology for influenza virus production in perfusion

Abstract

Process intensification and integration is crucial regarding an ever increasing pressure on manufacturing costs and capacities in biologics manufacturing. For virus production in perfusion mode, membrane-based alternating tangential flow filtration (ATF) and acoustic settler are the commonly described cell retention technologies. While acoustic settlers allow for continuous influenza virus harvesting, the use of commercially available membranes for ATF systems typically results in the accumulation of virus particles in the bioreactor vessel. Accordingly, with one single harvest at the end of a cultivation, this increases the risk of lowering the product quality. To assess which cell retention device would be most suitable for influenza A virus production, we compared various key performance figures using AGE1.CR.pIX cells at concentrations between 25 and 50 × 10 6 cells/mL at similar infection conditions using either an ATF system or an acoustic settler. Production yields, process-related impurities, and aggregation of viruses and other large molecules were evaluated. Taking into account the total number of virions from both the bioreactor and the harvest vessel, a 1.5-3.0-fold higher volumetric virus yield was obtained for the acoustic settler. In addition, fewer large-sized aggregates (virus particles and other molecules) were observed in the harvest taken directly from the bioreactor. In contrast, similar levels of process-related impurities (host cell dsDNA, total protein) were obtained in the harvest for both retention systems. Overall, a clear advantage was observed for continuous virus harvesting after the acoustic settler operation mode was optimized. This development may also allow direct integration of subsequent downstream processing steps. Key points• High suspension cell density, immortalized avian cell line, influenza vaccine.

Production of Modified Vaccinia Ankara Virus by Intensified Cell Cultures: A Comparison of Platform Technologies for Viral Vector Production

“…(2020). [ 28 ] For the specific case of the HFBR system, the CSVY was calculated taking into account the total number of cells produced as described previously for influenza A virus production with MDCK cells. [ 31 ] The concentration of infectious MVA virions produced (C vir, tot , virions mL −1 ) was calculated as follows: With Vir tot , the total number of virions produced in the harvest vessel and in the bioreactor (if required cumulated over several consecutive runs using the same bioreactor) as described by Granicher et al.…”

“…Both systems were operated under optimized process parameters determined previously for influenza A virus production. [ 28,29 ] Compared to the membrane‐based STR‐ATF system, STR‐AS and STR‐IS systems enabled continuous virus harvesting.…”

Application of an Inclined Settler for Cell Culture-Based Influenza A Virus Production in Perfusion Mode

“…Figure 1). e Optimum process parameters were determined following a previous study (Gränicher et al, 2020).…”

“…For the experiments using the acoustic settler (AS; 10 L acoustic chamber model, 20 mL V w , SonoSep Technologies), an acoustic power of 3 W and 2.1 MHz frequency was applied to all runs (Gränicher et al, 2020). Cells were inoculated at 1.2 × 10 6 cells/mL in 650 mL V w .…”

“…In order to evaluate the impact of the heat exchanger and cooling during perfusion and continuous virus harvesting, an acoustic settler was used in a setting similar to a previous study (Gränicher et al, 2020). This cell retention device also enables continuous virus harvesting, but does not require the use of a heat exchanger.…”