title: Investigation of the interactions of critical scale-up parameters (pH, pO2and pCO2) on CHO batch performance and critical quality attributes.
abstract: Understanding process parameter interactions and their effects on mammalian cell cultivations is an essential requirement for robust process scale-up. Furthermore, knowledge of the relationship between the process parameters and the product critical quality attributes (CQAs) is necessary to satisfy quality by design guidelines. So far, mainly the effect of single parameters on CQAs was investigated. Here, we present a comprehensive study to investigate the interactions of scale-up relevant parameters as pH, pO2and pCO2on CHO cell physiology, process performance and CQAs, which was based on design of experiments and extended product quality analytics. The study used a novel control strategy in which process parameters were decoupled from each other, and thus allowed their individual control at defined set points. Besides having identified the impact of single parameters on process performance and product quality, further significant interaction effects of process parameters on specific cell growth, specific productivity and amino acid metabolism could be derived using this method. Concerning single parameter effects, several monoclonal antibody (mAb) charge variants were affected by process pCO2and pH. N-glycosylation analysis showed positive correlations between mAb sialylation and high pH values as well as a relationship between high mannose variants and process pH. This study additionally revealed several interaction effects as process pH and pCO2interactions on mAb charge variants and N-glycosylation pattern. Hence, through our process control strategy and multivariate investigation, novel significant process parameter interactions and single effects were identified which have to be taken into account especially for process scale-up.
authors.affiliation: Research Division Biochemical Engineering, Vienna University of Technology, Gumpendorferstrasse 1a 166/4, Vienna, 1060, Austria.|CD Laboratory on Mechanistic and Physiological Methods for Improved Bioprocesses, Vienna University of Technology, Gumpendorferstrasse 1a/166, 1060, Vienna, Austria.
authors.forename: Matthias
authors.initials: M
authors.lastname: Brunner
authors.affiliation: Research Division Biochemical Engineering, Vienna University of Technology, Gumpendorferstrasse 1a 166/4, Vienna, 1060, Austria.|CD Laboratory on Mechanistic and Physiological Methods for Improved Bioprocesses, Vienna University of Technology, Gumpendorferstrasse 1a/166, 1060, Vienna, Austria.
authors.forename: Jens
authors.initials: J
authors.lastname: Fricke
authors.affiliation: Research Division Biochemical Engineering, Vienna University of Technology, Gumpendorferstrasse 1a 166/4, Vienna, 1060, Austria.|CD Laboratory on Mechanistic and Physiological Methods for Improved Bioprocesses, Vienna University of Technology, Gumpendorferstrasse 1a/166, 1060, Vienna, Austria.
authors.forename: Paul
authors.initials: P
authors.lastname: Kroll
authors.affiliation: Research Division Biochemical Engineering, Vienna University of Technology, Gumpendorferstrasse 1a 166/4, Vienna, 1060, Austria. christoph.herwig@tuwien.ac.at.|CD Laboratory on Mechanistic and Physiological Methods for Improved Bioprocesses, Vienna University of Technology, Gumpendorferstrasse 1a/166, 1060, Vienna, Austria. christoph.herwig@tuwien.ac.at.
authors.forename: Christoph
authors.initials: C
authors.lastname: Herwig
mesh_terms: D000818:Animals; D016466:CHO Cells; D002245:Carbon Dioxide / Q000378:metabolism*; D018929:Cell Culture Techniques / Q000379:methods*; D006224:Cricetinae; D003412:Cricetulus; D006863:Hydrogen-Ion Concentration; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen
keywords: CHO cell culture; Design of experiments; Monoclonal antibody CQA; Process parameter; Scale-up