Metal ions can be enzyme cofactors and can directly influence the kinetics of biochemical reactions that also influence the biological production and quality attributes of therapeutic proteins, such as glycan formation and distribution. However, the concentrations of metals in commercially available chemically defined media can range from 1 to 25,000 ppb. Because such concentration changes can impact cell growth, manufacturing yield and product quality the alteration/fluctuation in media composition should be well controlled to maintain product quality. Here, we describe a platform of analytical methods to determine the composition of several metals in different sample matrices using an advanced automated Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). These methods, validated to ICH Q2R1 regulatory validation parameters, were successfully applied to- (a) screen cell culture media; (b) determine changes in the metal concentration during cell growth in spinner flasks, and, (c) determine effect on the glycosylation pattern and homogeneity of an IgG3:κ produced from a murine-hybridoma cell line in bench-top parallel bioreactors due to a spike in copper and iron concentration. Our results show that maintenance of metal content in the cell culture media is critical for product consistency of the IgG3:κ produced.
Keywords: CHO cells; Chemically defined medium; Glycosylation; Hybridoma-cells; Parallel bioreactors; Therapeutic proteins.
Published by Elsevier B.V.