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AbstractThe pharmaceutical industry employs various strategies to improve cell productivity. These strategies include process intensification, culture media improvement, clonal selection, media supplementation and genetic engineering of cells. However, improved cell productivity has inherent risk of impacting product quality attributes (PQA). PQAs may affect the products’ efficacy via stability, bioavailability, or in vivo bioactivity. Variations in manufacturing process may introduce heterogeneity in the products by altering the type and extent of N-glycosylation, which is a PQA of therapeutic proteins. We investigated the effect of different cell densities representing increasing process intensification in a perfusion cell culture on the production of an IgG1-κ monoclonal antibody from a CHO-K1 cell line. This antibody is glycosylated both on light chain and heavy chain. Our results showed that the contents of glycosylation of IgG1-κ mAb increased in G0F and fucosylated type glycans as a group, whereas sialylated type glycans decreased, for the mAb whole protein. Overall, significant differences were observed in amounts of G0F, G1F, G0, G2FS1, and G2FS2 type glycans across all process intensification levels. G2FS2 and G2 type N-glycans were predominantly quantifiable from light chain rather than heavy chain. It may be concluded that there is a potential impact to product quality attributes of therapeutic proteins during process intensification via perfusion cell culture that needs to be assessed. Since during perfusion cell culture the product is collected throughout the duration of the process, lot allocation needs careful attention to process parameters, as PQAs are affected by the critical process parameters (CPPs). Key points• Molecular integrity may suffer with increasing process intensity.• Galactosylated and sialylated N-glycans may decrease.• Perfusion culture appears to maintain protein charge structure.
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Dynamic pH profiles drive higher cell‐specific and volumetric productivity
Abstract Mammalian cell cultures in bioreactors rely heavily on critical process parameter control to ensure optimal growth, productivity, and reproducibility to produce recombinant therapeutic proteins. Culture pH has been shown to be a critical parameter that influences growth, productivity, and critical quality attributes. Typically, pH is either controlled to a set‐point throughout the culture or uses a single pH shift to achieve higher productivity and more desirable charge variant profiles. The pH is usually maintained by CO2and base additions. For CO2controlled cultures, using a set‐point can result in an accumulation of CO2, which has detrimental effects on mammalian cell growth and protein production. In this study, a dynamic pH profile was implemented that allowed the pH control in the bioreactor to mimic the natural uncontrolled pH profile observed in shake flask cultures. This dynamic pH profile employs multiple pH shifts during the exponential phase of a single IgG1producing CHO‐K1 cell line. The results show that a dynamic pH profile was able to successfully alleviate CO2accumulation and increase the cell‐specific, as well as overall culture productivity. Impacts of the dynamic pH profile on product quality attributes, including glycosylation and charge variants, were also evaluated, showing mixed impacts on the glycosylation pattern and a positive impact on charge variants. Since the ideal glycosylation pattern is highly dependent on the intended function of the recombinant antibody, impacts on product quality should be evaluated on a “per process” basis.
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- Award ID(s):
- 1736123
- PAR ID:
- 10662665
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Biotechnology Progress
- ISSN:
- 8756-7938
- Subject(s) / Keyword(s):
- CHO CO2 accumulation fed-batch pH control product quality productivity
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1002/btpr.70080
