Closed loop control of lactate concentration in mammalian cell culture by Raman spectroscopy leads to improved cell density, viability, and biopharmaceutical protein production. Issue 11 (9th June 2016)

• Record Type: Journal Article
• Authors: Matthews, Thomas E.; Berry, Brandon N.; Smelko, John; Moretto, Justin; Moore, Brandon; Wiltberger, Kelly
• Is Part Of: Biotechnology and bioengineering. Volume 113:Issue 11(2016)
• Page Start: 2416
• Page End: 2424
• Publication Date: 2016-06-09
• Subjects: cell culture -- chemometrics -- Raman -- multivariate calibration -- process analytical technology -- advanced process control; Biotechnology -- Periodicals; Bioengineering -- Periodicals; 660.6
• DOI: 10.1002/bit.26018
• Languages: English
• ISSNs: 0006-3592

Abstract

ABSTRACT: Accumulation of lactate in mammalian cell culture often negatively impacts culture performance, impeding production of therapeutic proteins. Many efforts have been made to limit the accumulation of lactate in cell culture. Here, we describe a closed loop control scheme based on online spectroscopic measurements of glucose and lactate concentrations. A Raman spectroscopy probe was used to monitor a fed‐batch mammalian cell culture and predict glucose and lactate concentrations via multivariate calibration using partial least squares regression (PLS). The PLS models had a root mean squared error of prediction (RMSEP) of 0.27 g/L for glucose and 0.20 g/L for lactate. All glucose feeding was controlled by the Raman PLS model predictions. Glucose was automatically fed when lactate levels were beneath a setpoint (either 4.0 or 2.5 g/L) and glucose was below its own setpoint (0.5 g/L). This control scheme was successful in maintaining lactate levels at an arbitrary setpoint throughout the culture, as compared to the eventual accumulate of lactate to 8.0 g/L in the historical process. Automated control of lactate by restricted glucose feeding led to improvements in culture duration, viability, productivity, and robustness. Culture duration was extended from 11 to 13 days, and harvest titer increased 85% over the historical process. Biotechnol. Bioeng. 2016;113: 2416–2424. © 2016 Wiley Periodicals, Inc. Abstract : Online Raman spectroscopy in mammalian cell culture was used to monitor concentrations of glucose and lactate in production bioreactors.Glucose feeding was completely controlled by Raman predictions, and by gating glucose feeding to lactate levels it was possible to control lactate levels at arbitrary setpoints and substantially improved culture performance of a commercial biopharmaceutical process.