Stability and Requirement for Thiamin in a Cell Culture Feed Used to Produce New Biological Entities.

Thiamin is susceptible to heat and oxidation, which is a concern for the development of concentrated and room temperature stable feeds used to produce recombinant proteins. Hence, it is critical to understand the reactivity and necessity of the vitamin in liquid feeds to be able to either develop mitigation strategies to stabilize the vitamin or to remove thiamin from formulations if it is unnecessary. LC-MS/MS was used to investigate thiamin stability in different liquid feed formulations and to identify thiamin degradation products. Results indicate oxidation of thiamin and interaction with amino acids, keto acids, and sulfur containing components. Thiamin necessity in feed was assessed during a fed batch experiment, focusing on cell performance and critical quality attributes of the produced recombinant proteins. The impact of thiamin depletion in the feed on the intra- and extracellular metabolome was investigated using untargeted LC-MS/MS. Results indicate that thiamin can be removed from the feed without affecting the performance or the intra- and extracellular metabolome of the tested cell lines. Overall, profound insights on thiamin reactivity and necessity are presented in this study, suggesting the removal of the dispensable and instable vitamin as a simple means for the development of next generation feeds used to produce therapeutic biological entities.