Impact of preparation pH and temperature on amino acid stability of highly concentrated cell culture feed media

Abstract

BACKGROUND The stability of amino acids (AAs) in a highly concentrated cell culture medium is affected by medium preparation and storage conditions. Variability in the concentration of medium components (including AAs) can influence cell culture performance and product quality attributes. RESULTS In this report, the impact of preparation pH, preparation temperature, and storage temperature was evaluated on the stability of 16 AAs in a highly concentrated cell culture feed medium. Optimizing the medium pH enabled an increase in the initial feed medium concentration by 30% plus 3.9 g L−1 tyrosine with no observed precipitation after 28 days. Up to 6.0 g L−1 tyrosine can be supplemented in the medium at ~pH 10 without precipitation. Moreover, preparing the medium at 40–50 °C prevented precipitation during storage at 4–8 °C. A slight negative impact on AA stability during this high‐temperature preparation was observed, but this impact was negligible relative to the AA degradation observed during extended storage of media prepared at 37 °C. The optimal preparation pH and temperature allowed the concentrated medium to be stored at 4–8 °C with minimal AA degradation and without precipitation. These discoveries were further supported by principal component analysis of AA profile similarity before and after storage at different pH and temperature conditions. CONCLUSION This study describes the medium preparation parameters to improve AA stability and mitigate precipitation issues. The optimization strategy will facilitate the development of robust cell culture production processes. © 2022 Society of Chemical Industry (SCI).

Antibody charge variant modulation by in vitro enzymatic treatment in different Chinese hamster ovary cell cultures

“…9 The CpB treatment protocol was also applied to improve the main peak by removing C-terminal lysines for mAb-A and mAb-B production in this study. In addition to three widely used in vivo CHO cell culture improvement strategies, including cell line engineering, [36][37][38] media development, [39][40][41][42][43] and process parameter optimization, 32,44,45 in vitro enzymatic treatments may represent useful options for titer improvement and control of critical quality attributes. Although cell culture media and process parameters are environmental factors, the reason why we defined as in vivo above is because in vivo metabolisms within cells play a major role, while the CpB treatment is an in vitro reaction regardless of cells present or not.…”