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Dutton, Roshni L.; Scharer, Jeno M.; Moo‐Young, Murray

doi:10.1023/a:1007940119503

Cited by 39 publications

(7 citation statements)

References 33 publications

(68 reference statements)

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“…S and G 2 /M) to the total productivity. A similar outcome is observed if the productivity is evaluated in terms of the cumulative cell hours [68] and the analysis is broken down per cell cycle phase [10]. Both a partially growth associated productivity and a better correlation towards the G 1 /G 0 phase is observed.…”

Section: Discussionsupporting

confidence: 68%

Cyclin and DNA Distributed Cell Cycle Model for GS-NS0 Cells

et al. 2015

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Mammalian cell cultures are intrinsically heterogeneous at different scales (molecular to bioreactor). The cell cycle is at the centre of capturing heterogeneity since it plays a critical role in the growth, death, and productivity of mammalian cell cultures. Current cell cycle models use biological variables (mass/volume/age) that are non-mechanistic, and difficult to experimentally determine, to describe cell cycle transition and capture culture heterogeneity. To address this problem, cyclins—key molecules that regulate cell cycle transition—have been utilized. Herein, a novel integrated experimental-modelling platform is presented whereby experimental quantification of key cell cycle metrics (cell cycle timings, cell cycle fractions, and cyclin expression determined by flow cytometry) is used to develop a cyclin and DNA distributed model for the industrially relevant cell line, GS-NS0. Cyclins/DNA synthesis rates were linked to stimulatory/inhibitory factors in the culture medium, which ultimately affect cell growth. Cell antibody productivity was characterized using cell cycle-specific production rates. The solution method delivered fast computational time that renders the model’s use suitable for model-based applications. Model structure was studied by global sensitivity analysis (GSA), which identified parameters with a significant effect on the model output, followed by re-estimation of its significant parameters from a control set of batch experiments. A good model fit to the experimental data, both at the cell cycle and viable cell density levels, was observed. The cell population heterogeneity of disturbed (after cell arrest) and undisturbed cell growth was captured proving the versatility of the modelling approach. Cell cycle models able to capture population heterogeneity facilitate in depth understanding of these complex systems and enable systematic formulation of culture strategies to improve growth and productivity. It is envisaged that this modelling approach will pave the model-based development of industrial cell lines and clinical studies.

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Section: Discussionsupporting

confidence: 68%

Cyclin and DNA Distributed Cell Cycle Model for GS-NS0 Cells

et al. 2015

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“…31 Equation (1) defines the cumulative volumetric cell-hours (CH VOL ): 31 Equation (1) defines the cumulative volumetric cell-hours (CH VOL ):…”

Section: Biomass and Productivity Data Treatmentmentioning

confidence: 99%

Investigation of the effects of oxidative stress‐inducing factors on culturing and productivity of Bordetella pertussis

Zavatti

Budman

Legge

et al. 2019

Biotechnology Progress

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The stress response of Bordetella pertussis during fermentation was assessed by means of fluorescence-based techniques. During the manufacturing of vaccines, B. pertussis is subjected to stress during adaptation to a new environment and operating conditions in the bioreactor, which can have harmful consequences on growth and protein yield.In this study, stress was imposed by varying the percentage of dissolved oxygen (DO) and inoculum size, and by adding rotenone and hydrogen peroxide. In this study, fluorescence spectroscopy is used as a tool for measuring oxidative stress. High levels of DO during fed-batch operation had no detrimental effect on growth, but the specific productivity of pertactin (PRN) decreased. Cultures that were started with an inoculum size that was 10 times smaller than the control resulted in significantly less PRN as compared to controls where reduction was more significant in flasks as compared to bioreactors. A comparison of filtered to heat-sterilized media revealed that filtered media offered a protective effect against H 2 O 2 . Heat sterilization of the media might result in the destruction of components that offer protection against oxidative stress.Nonetheless, filter sterilization on its own would be insufficient for large-scale manufacturing. It should be emphasized that the effects of these stressors while investigating for other microorganisms have not been studied for B. pertussis. K E Y W O R D SBordetella pertussis, flow cytometry, fluorescence spectroscopy, oxidative stress, pertactin

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“…The viability index (VI) is a parameter that describes cell population size, endurance, and, importantly, the associated biological capacity for production (e.g., biosynthesis of protein product), and is therefore useful in assessing culture and media performance (Dutton et al 1998). VI is calculated as the numerical integral of the log mean viable cell density at time steps (t j?1 -t j ) over the period i to f:…”

Section: Viability Indexmentioning

confidence: 99%

“…In order to do so we must select a measure of quantity. Specific productivity, a measure of the per-cell, per-hour productivity of a culture (Dutton et al 1998), is a useful tool for analyzing the cellular efficiency of a cell culture system, but the primary metric of interest to industry is the volumetric productivity, [P], measured at the end of the culture (final titer). With this measure of quantity made the focus, we can expand QI into another metric, Titer Quality, TQ, to simultaneously assess both the protein quantity and protein glycan quality of an entire batch:…”

Section: Mab Glycan Profilementioning

confidence: 99%

“…3 M6, containing high levels of HYPEP TM 1510 and SITE but low levels of UMG and LM1, exhibited a nearly twofold increase in the maintenance of population viability over the positive control BIOGRO CHO cell culture, but the volumetric productivity and quality throughout the course of a culture. Furthermore, specific TQ (q TQ ) can be calculated using the concept of VI, as described by Dutton (1998), describing the per-cell, per-hour productivity and glycan quality of a particular cell culture system:…”

Section: Culture Performance Using Qi and Tqmentioning

confidence: 99%

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A simultaneous assessment metric for MAb quantity and glycan quality

et al. 2016

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As a critical quality attribute, glycosylation represents an important consideration when analyzing the success of a glycoprotein production process. Though critical, glycosylation is not the only measure of culture success; other factors, including culture size, maintenance, and productivity, are also critical. A new metric was developed to address both product quality, as measured through glycosylation, and product quantity, as measured through product concentration. A monoclonal antibody Chinese hamster ovary cell culture model system was used to assess this metric across various media formulations. In a model test system, the metric discriminated that some media supplements had a net positive impact on productivity and glycosylation, while others had a net negative impact on productivity and glycosylation.

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Untitled

Cited by 39 publications

References 33 publications

Cyclin and DNA Distributed Cell Cycle Model for GS-NS0 Cells

Cyclin and DNA Distributed Cell Cycle Model for GS-NS0 Cells

Investigation of the effects of oxidative stress‐inducing factors on culturing and productivity of Bordetella pertussis

A simultaneous assessment metric for MAb quantity and glycan quality

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