Overcoming challenges in WAVE bioreactors without feedback controls for pH and dissolved oxygen

Self Cite

Recent reports highlight the impact of copper on lactate metabolism: CHO cell cultures with higher initial copper levels shift to net lactate consumption and yield lower final lactate and higher titers. These studies investigated the effects of copper on metabolite and transcript profiles, but did not measure in detail the dependences of cell culture performance and product quality on copper concentrations. To more thoroughly map these dependences, we explored the effects of various copper treatments on four recombinant CHO cell lines. In the first cell line, when extracellular copper remained above the limit of detection (LOD), cultures shifted to net lactate consumption and yielded comparable performances irrespective of the differences in copper levels; when extracellular copper dropped below LOD (∼13 nM), cultures failed to shift to net lactate consumption, and yielded significantly lower product titers. Across the four cell lines, the ability to grow and consume lactate seemed to depend on the presence of a minimum level of copper, beyond which there were no further gains in culture performance. Although this minimum cellular copper requirement could not be directly quantified, we estimated its probable range for the first cell line by applying several assumptions. Even when different copper concentrations did not affect cell culture performance, they affected product quality profiles: higher initial copper concentrations increased the basic variants in the recombinant IgG1 products. Therefore, in optimizing chemically defined media, it is important to select a copper concentration that is adequate and achieves desired product quality attributes.

Section: Resultsmentioning

confidence: 95%

Effects of copper on CHO cells: Cellular requirements and product quality considerations

Yuk

Russell²,

Yun³

et al. 2014

Self Cite

“…The volumetric oxygen transfer coefficient, k L a , in liquid medium was estimated in a cell‐free system by a dynamic method, as previously described . Dissolved oxygen (DO) concentration was measured by a microsensor Microx TX3 (Presens, Germany).…”

Section: Methodsmentioning

confidence: 99%

Large‐scale culture of a megakaryocytic progenitor cell line with a single‐use bioreactor system

Nurhayati

Ojima

Dohda

et al. 2017

The increasing application of regenerative medicine has generated a growing demand for stem cells and their derivatives. Single-use bioreactors offer an attractive platform for stem cell expansion owing to their scalability for large-scale production and feasibility of meeting clinical-grade standards. The current work evaluated the capacity of a single-use bioreactor system (1 L working volume) for expanding Meg01 cells, a megakaryocytic (MK) progenitor cell line. Oxygen supply was provided by surface aeration to minimize foaming and orbital shaking was used to promote oxygen transfer. Oxygen transfer rates (k a) of shaking speeds 50, 100, and 125 rpm were estimated to be 0.39, 1.12, and 10.45 h , respectively. Shaking speed was a critical factor for optimizing cell growth. At 50 rpm, Meg01 cells exhibited restricted growth due to insufficient mixing. A negative effect occurred when the shaking speed was increased to 125 rpm, likely caused by high hydrodynamic shear stress. The bioreactor culture achieved the highest growth profile when shaken at 100 rpm, achieving a total expansion rate up to 5.7-fold with a total cell number of 1.2 ± 0.2 × 10 cells L . In addition, cells expanded using the bioreactor system could maintain their potency to differentiate following the MK lineage, as analyzed from specific surface protein and morphological similarity with the cells grown in the conventional culturing system. Our study reports the impact of operational variables such as shaking speed for growth profile and MK differentiation potential of a progenitor cell line in a single-use bioreactor. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:362-369, 2018.

“…In small‐scale operations, the use of disposable bioreactors (Figure ) has been increasing in the production of biotechnology products for medical use . These bioreactors are purchased as sterile ready‐to‐use devices that are disposed of after a single use.…”

Section: Bioprocess Engineering Aspects Of Insect Cell Culturementioning

confidence: 99%

Protein production using the baculovirus‐insect cell expression system

Contreras-Gómez

Sánchez-Mirón

Camacho

et al. 2013

133

104

The baculovirus-insect cell expression system is widely used in producing recombinant proteins. This review is focused on the use of this expression system in developing bioprocesses for producing proteins of interest. The issues addressed include: the baculovirus biology and genetic manipulation to improve protein expression and quality; the suppression of proteolysis associated with the viral enzymes; the engineering of the insect cell lines for improved capability in glycosylation and folding of the expressed proteins; the impact of baculovirus on the host cell and its implications for protein production; the effects of the growth medium on metabolism of the host cell; the bioreactors and the associated operational aspects; and downstream processing of the product. All these factors strongly affect the production of recombinant proteins. The current state of knowledge is reviewed.