Performance monitoring of a mammalian cell based bioprocess using Raman spectroscopy

Abstract

Being able to predict the final product yield at all stages in long-running, industrial, mammalian cell culture processes is vital for both operational efficiency, process consistency, and the implementation of quality by design (QbD) practices. Here we used Raman spectroscopy to monitor (in terms of glycoprotein yield prediction) a fed-batch fermentation from start to finish. Raman data were collected from 12 different time points in a Chinese hamster ovary (CHO) based manufacturing process and across 37 separate production runs. The samples comprised of clarified bioprocess broths extracted from the CHO cell based process with varying amounts of fresh and spent cell culture media. Competitive adaptive reweighted sampling (CoAdReS) and ant colony optimization (ACO) variable selection methods were used to enhance the predictive ability of the chemometric models by removing unnecessary spectral information. Using CoAdReS accurate prediction models (relative error of predictions between 2.1% and 3.3%) were built for the final glycoprotein yield at every stage of the bioprocess from small scale up to the final 5000 L bioreactor. This result reinforces our previous studies which indicate that media quality is one of the most significant factors determining the efficiency of industrial CHO-cell processes. This Raman based approach could thus be used to manage production in terms of selecting which small scale batches are progressed to large-scale manufacture, thus improving process efficiency significantly.

Applications of Raman Spectroscopy in Biopharmaceutical Manufacturing: A Short Review

“…At this stage in the data analysis process, it is often beneficial to try to increase model sensitivity for a specific analyte by removing any excess (unrelated) spectral variables. As with all other aspects of chemometrics, there are many different algorithms that can be used for variable selection, [112][113][114][115] in our group ant colony optimization (ACO) [116][117][118] has been used most often. 4.…”

“…This is not a trivial undertaking as many of the biogenic samples generated by BioPharma are biologically, chemically, and physically unstable and even apparently minor differences in sample handling (e.g., stirred not shaken) can, and will, cause major differences in measurements for all techniques. 28,32,[34][35][36]58,59,73,118,131 Sample Handling A very important issue in BioPharma concerns the physical nature of the sample and whether one is testing solids or liquids. Solid-state cell culture media, for example, are complex powders (e.g., media, hydrolysates, etc.)…”

“…164 Since the first offline Raman analysis of spent cell culture media in the late 1990s, the technology has progressed to a point where the bioreactor broth is now analyzed in real time, 159,163 and the yield of a bioprocess could be predicted. 118,165 In 2014, Craven et al demonstrated the next logical step, a Raman analysis that could be used to control a bioprocess; the ''nonlinear model predictive controller'' (NMPC) used online Raman measurements and a closed-loop feedback control system to maintain the glucose concentration at 11 mM inside a CHO bioprocess (15 L) bioreactor (Figure 11). 166 A similar approach was recently published for the control of lactate concentration during culture.…”

Calibration, standardization, and quantitative analysis of multidimensional fluorescence (MDF) measurements on complex mixtures (IUPAC Technical Report)

“…This approach has been implemented successfully for the quantitative analysis of various complex biogenic samples from, e.g. wine [50], milk [40,51], food [5,52,53], and cell culture media [4,35,54]. In many of these applications, there are generally multiple fluorophores present, often at high concentration.…”

Label‐free live cell imaging by Confocal Raman Microscopy identifies CHO host and producer cell lines

“…detection of impurities such as 2,4‐dinitrotoluene vapor to locate landmines 6, 8). In CHO bioprocessing, Raman spectroscopy together with chemometrics 9, 10, 11 was proven useful for in situ monitoring of cell culture broth, in 2 to 5000 L bioprocesses 12, 13, 14. Still, information on a single‐cell‐basis, e.g.…”