1
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Population balance modelling captures host cell protein dynamics in CHO cell cultures. PLoS One 2022; 17:e0265886. [PMID: 35320326 PMCID: PMC8959726 DOI: 10.1371/journal.pone.0265886] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 03/09/2022] [Indexed: 11/19/2022] Open
Abstract
Monoclonal antibodies (mAbs) have been extensively studied for their wide therapeutic and research applications. Increases in mAb titre has been achieved mainly by cell culture media/feed improvement and cell line engineering to increase cell density and specific mAb productivity. However, this improvement has shifted the bottleneck to downstream purification steps. The higher accumulation of the main cell-derived impurities, host cell proteins (HCPs), in the supernatant can negatively affect product integrity and immunogenicity in addition to increasing the cost of capture and polishing steps. Mathematical modelling of bioprocess dynamics is a valuable tool to improve industrial production at fast rate and low cost. Herein, a single stage volume-based population balance model (PBM) has been built to capture Chinese hamster ovary (CHO) cell behaviour in fed-batch bioreactors. Using cell volume as the internal variable, the model captures the dynamics of mAb and HCP accumulation extracellularly under physiological and mild hypothermic culture conditions. Model-based analysis and orthogonal measurements of lactate dehydrogenase activity and double-stranded DNA concentration in the supernatant show that a significant proportion of HCPs found in the extracellular matrix is secreted by viable cells. The PBM then served as a platform for generating operating strategies that optimise antibody titre and increase cost-efficiency while minimising impurity levels.
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2
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Rout-Pitt N, Donnelley M, Parsons D. In vitro optimization of miniature bronchoscope lentiviral vector delivery for the small animal lung. Exp Lung Res 2021; 47:417-425. [PMID: 34632894 DOI: 10.1080/01902148.2021.1989523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Current gene therapy delivery protocols for small animal lungs typically utilize indirect dose delivery via the nasal airways, or bolus delivery directly into the trachea. Both methods can result in variable transduction throughout the lung, as well as between animals, and cannot be applied in a targeted manner. To minimize variability and improve lung coverage we previously developed and validated a method to visualize and dose gene vectors into pre-selected lobes of rat lungs using a mini-bronchoscope. Lentiviral (LV) vectors are known to be fragile and can be inactivated easily by temperature or the application of shear stresses. There are several ways that the bronchoscope could be configured to deliver the LV vector, and these could result in different amounts of functional LV vector being delivered to the lung. This study evaluated several methods of LV vector delivery through the bronchoscope, and how flow rates and LV vector stabilizing diluents impact LV vector delivery. NIH-3T3 cells were exposed to LV vector containing the green fluorescent protein (GFP) reporter gene using various bronchoscopic delivery techniques and the number of GFP-positive cells produced by each was quantified by flow cytometry. The results showed that directly drawing the LV vector into the bronchoscope tip resulted in 80-90% recovery of viable vector, and was also the simplest method of delivery. The fluid delivery rate and the use of stabilizing serum in the vector diluent had no effect on the viability of the LV vector delivered. These findings can be used to optimize LV vector dose delivery into individual lung lobes of small animal models.
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Affiliation(s)
- Nathan Rout-Pitt
- Robinson Research Institute, University of Adelaide, Adelaide, South Australia.,Adelaide Medical School, University of Adelaide, Adelaide, South Australia.,Department of Respiratory and Sleep Medicine, Women's and Children's Hospital, North Adelaide, South Australia
| | - Martin Donnelley
- Robinson Research Institute, University of Adelaide, Adelaide, South Australia.,Adelaide Medical School, University of Adelaide, Adelaide, South Australia.,Department of Respiratory and Sleep Medicine, Women's and Children's Hospital, North Adelaide, South Australia
| | - David Parsons
- Robinson Research Institute, University of Adelaide, Adelaide, South Australia.,Adelaide Medical School, University of Adelaide, Adelaide, South Australia.,Department of Respiratory and Sleep Medicine, Women's and Children's Hospital, North Adelaide, South Australia
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3
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Mehdipour M, Daghigh Kia H, Martínez-Pastor F. Poloxamer 188 exerts a cryoprotective effect on rooster sperm and allows decreasing glycerol concentration in the freezing extender. Poult Sci 2020; 99:6212-6220. [PMID: 33142539 PMCID: PMC7647912 DOI: 10.1016/j.psj.2020.08.041] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 07/16/2020] [Accepted: 08/12/2020] [Indexed: 01/27/2023] Open
Abstract
Glycerol is the most widely used cryoprotectant for rooster sperm because it declines the mechanical damage to sperm during the freezing process. Despite its high molecular weight and viscosity, which may be cytotoxic, glycerol can cause damage to cells during the cryopreservation process, resulting in less fertility. Poloxamer 188 (P188) is an embryo cryopreservation supplement effective in many species and also for cell lines and plant cells. We tested the suitability of P188 in the cryopreservation of rooster sperm, considering post-thawing motility, abnormalities, membrane functionality (hypo-osmotic swelling test), mitochondrial activity, viability, apoptosis status, reactive oxygen species production, and ATP content after thawing and the fertility and hatchability after AI. We carried out a factorial experiment with glycerol concentrations of 2% glycerol (G2) and 8% glycerol (G8) and P188 concentrations of 0% (P0), 0.1% (P0.1), 0.5% (P0.5), and 1% (P1) as fixed effects, with replicate (seven) as a random effect. Interactions between glycerol and P188 were found, with G2P1 yielding higher quality and fertility. G8P0.5 yielded better in most parameters, however, not reaching G2P1. G2P1 showed significantly higher results for total and progressive motility, kinetic parameters (average path velocity, straight-line velocity, and linearity), membrane functionality, viability, mitochondrial activity, and ATP content and lower apoptosis, dead sperm, and reactive oxygen species production. G2P1 resulted in the highest percentages of fertilized and hatched eggs, with no effects in the hatched eggs ratio. Interestingly, G2 was less efficient in many parameters than G8 when combined with P0 and P0.1, being equivalent to G8 with P0.5 and superior to any G8 treatment as G2P1. In conclusion, P188 could improve rooster semen cryopreservation and allow reduction of glycerol in extenders, with a consequent impact in the poultry industry.
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Affiliation(s)
- Mahdieh Mehdipour
- Department of Animal Science, College of Agriculture, University of Tabriz, Tabriz, Iran
| | - Hossein Daghigh Kia
- Department of Animal Science, College of Agriculture, University of Tabriz, Tabriz, Iran.
| | - Felipe Martínez-Pastor
- Institute of Animal Health and Cattle Development (INDEGSAL) and Department of Molecular Biology (Cell Biology), University of León, León 24071, Spain
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4
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Emmermacher J, Spura D, Cziommer J, Kilian D, Wollborn T, Fritsching U, Steingroewer J, Walther T, Gelinsky M, Lode A. Engineering considerations on extrusion-based bioprinting: interactions of material behavior, mechanical forces and cells in the printing needle. Biofabrication 2020; 12:025022. [PMID: 32050179 DOI: 10.1088/1758-5090/ab7553] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Systematic analysis of the extrusion process in 3D bioprinting is mandatory for process optimization concerning production speed, shape fidelity of the 3D construct and cell viability. In this study, we applied numerical and analytical modeling to describe the fluid flow inside the printing head based on a Herschel-Bulkley model. The presented analytical calculation method nicely reproduces the results of Computational Fluid Dynamics simulation concerning pressure drop over the printing head and maximal shear parameters at the outlet. An approach with dimensionless flow parameter enables the user to adapt rheological characteristics of a bioink, the printing pressure and needle diameter with regard to processing time, shear sensitivity of the integrated cells, shape fidelity and strand dimension. Bioinks consist of a blend of polymers and cells, which lead to a complex fluid behavior. In the present study, a bioink containing alginate, methylcellulose and agarose (AMA) was used as experimental model to compare the calculated with the experimental pressure gradient. With cultures of an immortalized human mesenchymal stem cell line and plant cells (basil) it was tested how cells influence the flow and how mechanical forces inside the printing needle affect cell viability. Influences on both sides increased with cell (aggregation) size as well as a less spherical shape. This study contributes to a systematic description of the extrusion-based bioprinting process and introduces a general strategy for process design, transferable to other bioinks.
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Affiliation(s)
- Julia Emmermacher
- Centre for Translational Bone, Joint and Soft Tissue Research, University Hospital Carl Gustav Carus, Faculty of Medicine, Technische Universität Dresden, Germany. Institute of Natural Materials Technology, Faculty of Mechanical Engineering, Technische Universität Dresden, Germany
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5
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Narayanappa AT, Mwilu S, Holdread S, Hammett K, Bu G, Dodson EC, Brooks JW. A rapid cell-based assay for determining poloxamer quality in CHO suspension cell culture. Biotechniques 2019; 67:98-109. [PMID: 31347927 DOI: 10.2144/btn-2019-0070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Poloxamers are water-soluble polymers that are widely used in cell culture bioprocessing to protect cells against shearing forces. Use of poor-quality poloxamers may lead to a drastic reduction in cell growth, viabilities and productivities in cell culture-based manufacturing. In order to evaluate poloxamer quality and promote more consistent performance, a rapid cell membrane adhesion to hydrocarbon assay was developed based on the adhesive properties of cell membranes to selective hydrocarbons. The assay can identify a poor-performing poloxamer characterized by significant drop in viable cell density and percent viability. The assay was verified across multiple good and bad poloxamer lots, and the results were in agreement with established cell growth and high-performance liquid chromatography assays.
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Affiliation(s)
| | - Sam Mwilu
- Advanced Bioprocessing, Thermo Fisher Scientific, 250 Schilling Circle, Hunt Valley, MD 21030, USA
| | - Stacy Holdread
- Advanced Bioprocessing, Thermo Fisher Scientific, 250 Schilling Circle, Hunt Valley, MD 21030, USA
| | - Kimesha Hammett
- Advanced Bioprocessing, Thermo Fisher Scientific, 250 Schilling Circle, Hunt Valley, MD 21030, USA
| | - George Bu
- Advanced Bioprocessing, Thermo Fisher Scientific, 250 Schilling Circle, Hunt Valley, MD 21030, USA
| | - Elizabeth C Dodson
- Advanced Bioprocessing, Thermo Fisher Scientific, 250 Schilling Circle, Hunt Valley, MD 21030, USA
| | - James W Brooks
- Advanced Bioprocessing, Thermo Fisher Scientific, 250 Schilling Circle, Hunt Valley, MD 21030, USA
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6
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Bareford L, Peng H, Ali A, Kolwyck D, Dickens J. Development of a rapid and reliable analytical method for screening poloxamer 188 for use in cell culture process. Biotechnol Prog 2019; 35:e2792. [PMID: 30816019 DOI: 10.1002/btpr.2792] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/15/2019] [Accepted: 02/25/2019] [Indexed: 11/12/2022]
Abstract
Poloxamer P188 is a common nonionic surfactant additive used in cell culture media as a cellular protectant from the hydrodynamic forces and shear stress during bioprocessing. Presence of a hydrophobic high molecular weight impurity contaminant has been shown to compromise its protective properties and lead to batch failure. In this work we present, a reliable, sensitive, and rapid analytical method to detect and quantify the contaminant impurity in poloxamer 188. This method replaces a laborious and time-consuming functional test in the form of a shake flask assay. The method is based upon reversed-phase liquid chromatography with charged aerosol detection, simple mobile phase compositions, and a three-step gradient. The method was optimized to resolve the impurity from the main P188 fraction in less than 10 min. Analytical method qualification and functional test comparison demonstrate equivalent or better high throughput impurity screening performance. Attempts to identify the impurity and establish suitable method positive control standards are also discussed.
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Affiliation(s)
| | - Haofan Peng
- Manufacturing Sciences, Biogen, Davis, North Carolina
| | - Amr Ali
- Analytical Development, Biogen, Cambridge, Massachusetts
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7
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Houang EM, Sham YY, Bates FS, Metzger JM. Muscle membrane integrity in Duchenne muscular dystrophy: recent advances in copolymer-based muscle membrane stabilizers. Skelet Muscle 2018; 8:31. [PMID: 30305165 PMCID: PMC6180502 DOI: 10.1186/s13395-018-0177-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 09/13/2018] [Indexed: 02/07/2023] Open
Abstract
The scientific premise, design, and structure-function analysis of chemical-based muscle membrane stabilizing block copolymers are reviewed here for applications in striated muscle membrane injury. Synthetic block copolymers have a rich history and wide array of applications from industry to biology. Potential for discovery is enabled by a large chemical space for block copolymers, including modifications in block copolymer mass, composition, and molecular architecture. Collectively, this presents an impressive chemical landscape to leverage distinct structure-function outcomes. Of particular relevance to biology and medicine, stabilization of damaged phospholipid membranes using amphiphilic block copolymers, classified as poloxamers or pluronics, has been the subject of increasing scientific inquiry. This review focuses on implementing block copolymers to protect fragile muscle membranes against mechanical stress. The review highlights interventions in Duchenne muscular dystrophy, a fatal disease of progressive muscle deterioration owing to marked instability of the striated muscle membrane. Biophysical and chemical engineering advances are presented that delineate and expand upon current understanding of copolymer-lipid membrane interactions and the mechanism of stabilization. The studies presented here serve to underscore the utility of copolymer discovery leading toward the therapeutic application of block copolymers in Duchenne muscular dystrophy and potentially other biomedical applications in which membrane integrity is compromised.
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Affiliation(s)
- Evelyne M. Houang
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, 6-125 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455 USA
| | - Yuk Y. Sham
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, 6-125 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455 USA
- University of Minnesota Informatics Institute, MN, USA
- Bioinformatics and Computational Biology Program, University of Minnesota, MN, USA
| | - Frank S. Bates
- Department of Chemical Engineering and Materials Science, University of Minnesota, MN, USA
| | - Joseph M. Metzger
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, 6-125 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455 USA
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8
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Guzniczak E, Jimenez M, Irwin M, Otto O, Willoughby N, Bridle H. Impact of poloxamer 188 (Pluronic F-68) additive on cell mechanical properties, quantification by real-time deformability cytometry. BIOMICROFLUIDICS 2018; 12:044118. [PMID: 30867863 PMCID: PMC6404947 DOI: 10.1063/1.5040316] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 08/03/2018] [Indexed: 06/09/2023]
Abstract
Advances in cellular therapies have led to the development of new approaches for cell product purification and formulation, e.g., utilizing cell endogenous properties such as size and deformability as a basis for separation from potentially harmful undesirable by-products. However, commonly used additives such as Pluronic F-68 and other poloxamer macromolecules can change the mechanical properties of cells and consequently alter their processing. In this paper, we quantified the short-term effect of Pluronic F-68 on the mechanotype of three different cell types (Jurkat cells, red blood cells, and human embryonic kidney cells) using real-time deformability cytometry. The impact of the additive concentration was assessed in terms of cell size and deformability. We observed that cells respond progressively to the presence of Pluronic F-68 within first 3 h of incubation and become significantly stiffer (p-value < 0.001) in comparison to a serum-free control and a control containing serum. We also observed that the short-term response manifested as cell stiffening is true (p-value < 0.001) for the concentration reaching 1% (w/v) of the poloxamer additive in tested buffers. Additionally, using flow cytometry, we assessed that changes in cell deformability triggered by addition of Pluronic F-68 are not accompanied by size or viability alterations.
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Affiliation(s)
- Ewa Guzniczak
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Science, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, United Kingdom
| | - Melanie Jimenez
- School of Engineering, Biomedical Engineering Division, University of Glasgow, Glasgow G12 8LT, United Kingdom
| | - Matthew Irwin
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Science, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, United Kingdom
| | - Oliver Otto
- ZIK HIKE, Centre for Innovation Competence - Humoral Immune Reactions in Cardiovascular Diseases, Biomechanics, University of Greifswald, Fleischmannstraße 42-44, 17489 Greifswald, Germany
| | - Nicholas Willoughby
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Science, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, United Kingdom
| | - Helen Bridle
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Science, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, United Kingdom
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9
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Kang N, Guo Q, Islamzada E, Ma H, Scott MD. Microfluidic determination of lymphocyte vascular deformability: effects of intracellular complexity and early immune activation. Integr Biol (Camb) 2018; 10:207-217. [DOI: 10.1039/c7ib00191f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Despite the critical importance of mechanical (rheological + extrudability) deformability in the vascular flow of lymphocytes, it has been poorly investigated due to the limitations of existing technological tools.
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Affiliation(s)
- Ning Kang
- Centre for Innovation
- Canadian Blood Services
- Life Sciences Centre
- Vancouver
- Canada
| | - Quan Guo
- Department of Mechanical Engineering
- University of British Columbia
- Vancouver
- Canada
| | - Emel Islamzada
- Department of Mechanical Engineering
- University of British Columbia
- Vancouver
- Canada
| | - Hongshen Ma
- Centre for Innovation
- Canadian Blood Services
- Life Sciences Centre
- Vancouver
- Canada
| | - Mark D. Scott
- Centre for Innovation
- Canadian Blood Services
- Life Sciences Centre
- Vancouver
- Canada
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10
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Gélinas JF, Davies LA, Gill DR, Hyde SC. Assessment of selected media supplements to improve F/HN lentiviral vector production yields. Sci Rep 2017; 7:10198. [PMID: 28860488 PMCID: PMC5579034 DOI: 10.1038/s41598-017-07893-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 05/31/2017] [Indexed: 12/01/2022] Open
Abstract
The development of lentiviral-based therapeutics is challenged by the high cost of current Good Manufacturing Practices (cGMP) production. Lentiviruses are enveloped viruses that capture a portion of the host cell membrane during budding, which then constitutes part of the virus particle. This process might lead to lipid and protein depletion in the cell membrane and affect cell viability. Furthermore, growth in suspension also causes stresses that can affect virus production yields. To assess the impact of these issues, selected supplements (Cholesterol Lipid Concentrate, Chemically Defined Lipid Concentrate, Lipid Mixture 1, Gelatin Peptone N3, N-Acetyl-L-Cysteine and Pluronic F-68) were assayed in order to improve production yields in a transient transfection production of a Sendai virus F/HN-pseudotyped HIV-1-based third generation lentiviral vector in FreeStyle 293 (serum-free media) in suspension. None of the supplements tested had a significant positive impact on lentiviral vector yields, but small non-significant improvements could be combined to increase vector production in a cell line where other conditions have been optimised.
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Affiliation(s)
- Jean-François Gélinas
- Gene Medicine Research Group, NDCLS, Radcliffe Department of Medicine, John Radcliffe Hospital, Oxford University, Oxford, UK
| | - Lee A Davies
- Gene Medicine Research Group, NDCLS, Radcliffe Department of Medicine, John Radcliffe Hospital, Oxford University, Oxford, UK.,United Kingdom Cystic Fibrosis Gene Therapy Consortium, Oxford, Edinburgh, London, UK
| | - Deborah R Gill
- Gene Medicine Research Group, NDCLS, Radcliffe Department of Medicine, John Radcliffe Hospital, Oxford University, Oxford, UK.,United Kingdom Cystic Fibrosis Gene Therapy Consortium, Oxford, Edinburgh, London, UK
| | - Stephen C Hyde
- Gene Medicine Research Group, NDCLS, Radcliffe Department of Medicine, John Radcliffe Hospital, Oxford University, Oxford, UK. .,United Kingdom Cystic Fibrosis Gene Therapy Consortium, Oxford, Edinburgh, London, UK.
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11
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Chang D, Fox R, Hicks E, Ferguson R, Chang K, Osborne D, Hu W, Velev OD. Investigation of interfacial properties of pure and mixed poloxamers for surfactant-mediated shear protection of mammalian cells. Colloids Surf B Biointerfaces 2017; 156:358-365. [DOI: 10.1016/j.colsurfb.2017.05.040] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 05/10/2017] [Accepted: 05/13/2017] [Indexed: 11/27/2022]
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12
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Poellmann MJ, Lee RC. Repair and Regeneration of the Wounded Cell Membrane. REGENERATIVE ENGINEERING AND TRANSLATIONAL MEDICINE 2017. [DOI: 10.1007/s40883-017-0031-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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13
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Impact of Pluronic ® F68 on hollow fiber filter-based perfusion culture performance. Bioprocess Biosyst Eng 2017; 40:1317-1326. [PMID: 28577048 DOI: 10.1007/s00449-017-1790-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 05/24/2017] [Indexed: 10/19/2022]
Abstract
High cell density is an important factor in achieving high bioreactor productivity. To meet the oxygen demand with density at >100 × 106 cells/mL, a frit sparger is often used. In this study, the impact of Pluronic® F68 on a perfusion process using a frit sparger was studied. The perfusion process was developed using an alternating tangential flow device with a 0.2 µm PES hollow fiber filter. Pluronic® F68 at 2 g/L was sufficient in preventing cell damage at gas flow rate of ~0.20 vvm from a drilled hole sparger (0.5 mm) but inadequate at ~0.025 vvm from a frit sparger (20 µm). Increase of Pluronic® F68 concentration to 5 g/L prevented cell death at up to ~0.10 vvm from the frit sparger and was able to maintain high cell density at high viability in the range of 60-80 × 106 cells/mL. Such positive effect was demonstrated in both 3- and 200-L bioreactors. Supplementing additional Pluronic® F68 was also effective in restoring cell growth/viability from low viability cultures. Increased Pluronic® F68 concentration had no adverse impact on target antibody, HCP, and Pluronic® F68 transmissions.
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14
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Chen A, Leith M, Tu R, Tahim G, Sudra A, Bhargava S. Effects of diluents on cell culture viability measured by automated cell counter. PLoS One 2017; 12:e0173375. [PMID: 28264018 PMCID: PMC5338812 DOI: 10.1371/journal.pone.0173375] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Accepted: 02/20/2017] [Indexed: 11/18/2022] Open
Abstract
Commercially available automated cell counters based on trypan blue dye-exclusion are widely used in industrial cell culture process development and manufacturing to increase throughput and eliminate inherent variability in subjective interpretation associated with manual hemocytometers. When using these cell counters, sample dilution is often necessary to stay within the assay measurement range; however, the effect of time and diluents on cell culture is not well understood. This report presents the adverse effect of phosphate buffered saline as a diluent on cell viability when used in combination with an automated cell counter. The reduced cell viability was attributed to shear stress introduced by the automated cell counter. Furthermore, length of time samples were incubated in phosphate buffered saline also contributed to the observed drop in cell viability. Finally, as erroneous viability measurements can severely impact process decisions and product quality, this report identifies several alternative diluents that can maintain cell culture viability over time in order to ensure accurate representation of cell culture conditions.
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Affiliation(s)
- Aaron Chen
- BioProcess Development, Seattle Genetics, Inc., Bothell, Washington, United States of America
- * E-mail:
| | - Matthew Leith
- BioProcess Development, Seattle Genetics, Inc., Bothell, Washington, United States of America
| | - Roger Tu
- BioProcess Development, Seattle Genetics, Inc., Bothell, Washington, United States of America
| | - Gurpreet Tahim
- BioProcess Development, Seattle Genetics, Inc., Bothell, Washington, United States of America
| | - Anish Sudra
- Clinical Manufacturing, Seattle Genetics, Inc., Bothell, Washington, United States of America
| | - Swapnil Bhargava
- BioProcess Development, Seattle Genetics, Inc., Bothell, Washington, United States of America
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15
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Delahaye M, Lawrence K, Ward SJ, Hoare M. An ultra scale-down analysis of the recovery by dead-end centrifugation of human cells for therapy. Biotechnol Bioeng 2015; 112:997-1011. [PMID: 25545057 PMCID: PMC4402021 DOI: 10.1002/bit.25519] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 11/28/2014] [Accepted: 12/09/2014] [Indexed: 01/07/2023]
Abstract
An ultra scale-down method is described to determine the response of cells to recovery by dead-end (batch) centrifugation under commercially defined manufacturing conditions. The key variables studied are the cell suspension hold time prior to centrifugation, the relative centrifugal force (RCF), time of centrifugation, cell pellet resuspension velocities, and number of resuspension passes. The cell critical quality attributes studied are the cell membrane integrity and the presence of selected surface markers. Greater hold times and higher RCF values for longer spin times all led to the increased loss of cell membrane integrity. However, this loss was found to occur during intense cell resuspension rather than the preceding centrifugation stage. Controlled resuspension at low stress conditions below a possible critical stress point led to essentially complete cell recovery even at conditions of extreme centrifugation (e.g., RCF of 10000 g for 30 mins) and long (∼2 h) holding times before centrifugation. The susceptibility to cell loss during resuspension under conditions of high stress depended on cell type and the age of cells before centrifugation and the level of matrix crosslinking within the cell pellet as determined by the presence of detachment enzymes or possibly the nature of the resuspension medium. Changes in cell surface markers were significant in some cases but to a lower extent than loss of cell membrane integrity. Biotechnol. Bioeng. 2015;112: 997–1011. © 2014 Wiley Periodicals, Inc.
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Affiliation(s)
- M Delahaye
- Department of Biochemical Engineering, Advanced Centre for Biochemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK
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16
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Palomares LA, Realpe M, Ramírez OT. An Overview of Cell Culture Engineering for the Insect Cell-Baculovirus Expression Vector System (BEVS). CELL ENGINEERING 2015. [DOI: 10.1007/978-3-319-10320-4_15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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17
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18
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Sengupta A, Dwivedi N, Kelly SC, Tucci L, Thadhani NN, Prausnitz MR. Poloxamer surfactant preserves cell viability during photoacoustic delivery of molecules into cells. Biotechnol Bioeng 2014; 112:405-15. [DOI: 10.1002/bit.25363] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 07/17/2014] [Accepted: 08/06/2014] [Indexed: 01/19/2023]
Affiliation(s)
- Aritra Sengupta
- School of Chemical and Biomolecular Engineering; Georgia Institute of Technology; Atlanta 30332 Georgia
| | - Nishant Dwivedi
- School of Chemical and Biomolecular Engineering; Georgia Institute of Technology; Atlanta 30332 Georgia
- School of Medicine; Boston University; Boston Massachusetts
| | - Sean C. Kelly
- School of Materials Science and Engineering; Georgia Institute of Technology; Atlanta Georgia
| | - Lara Tucci
- School of Chemical and Biomolecular Engineering; Georgia Institute of Technology; Atlanta 30332 Georgia
| | - Naresh N. Thadhani
- School of Materials Science and Engineering; Georgia Institute of Technology; Atlanta Georgia
| | - Mark R. Prausnitz
- School of Chemical and Biomolecular Engineering; Georgia Institute of Technology; Atlanta 30332 Georgia
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19
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Peng H, Hall KM, Clayton B, Wiltberger K, Hu W, Hughes E, Kane J, Ney R, Ryll T. Development of small scale cell culture models for screening poloxamer 188 lot-to-lot variation. Biotechnol Prog 2014; 30:1411-8. [DOI: 10.1002/btpr.1967] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 06/20/2014] [Indexed: 12/12/2022]
Affiliation(s)
- Haofan Peng
- Cell Culture Development, Biogen Idec; Research Triangle Park; 5000 Davis Drive NC 27709
| | - Kaitlyn M. Hall
- Cell Culture Development, Biogen Idec; Research Triangle Park; 5000 Davis Drive NC 27709
| | - Blake Clayton
- Cell Culture Development, Biogen Idec; Research Triangle Park; 5000 Davis Drive NC 27709
| | - Kelly Wiltberger
- Cell Culture Development, Biogen Idec; Research Triangle Park; 5000 Davis Drive NC 27709
| | - Weiwei Hu
- Cell Culture Development, Biogen Idec; Research Triangle Park; 5000 Davis Drive NC 27709
| | - Erik Hughes
- Manufacturing Sciences, Biogen Idec; Research Triangle Park; NC 27709
| | - John Kane
- Manufacturing Sciences, Biogen Idec; Research Triangle Park; NC 27709
| | - Rachel Ney
- Manufacturing Sciences, Biogen Idec; Research Triangle Park; NC 27709
| | - Thomas Ryll
- Cell Culture Development, Biogen Idec; Cambridge MA 02142
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20
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Kim TG, Cho YC, Chun BH, Park SH, Lee HS, Chung N. Poly-γ-glutamic acid enhances the quality of recombant erythropoietin produced by CHO cells. BIOTECHNOL BIOTEC EQ 2014; 28:350-354. [PMID: 26019520 PMCID: PMC4433941 DOI: 10.1080/13102818.2014.901675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The effect of poly-γ-glutamic acid (γPGA), which is produced by Bacillus sp., on the production of recombinant erythropoietin (rEPO) by Chinese hamster ovary (CHO) cells in suspension culture was evaluated. The growth, viability, and productivity of recombinant CHO cells were investigated in a chemically defined medium with 50 and 500 kD γPGAs at 0.075% or with Pluronic F68. Cell growth with the two γPGAs was lower than that with Pluronic F68 but significantly higher than that without any additive (control). The effect of additives on rEPO productivity was 50 kDa γPGA > 500 kDa γPGA > Pluronic F68 > control. Using EPO-dependent F-36E cells, we found that the effect of additives on rEPO quality was 500 kDa γPGA > 50 kDa γPGA > control > Pluronic F68. γPGA has an enhancement effect on the quality of rEPO produced by CHO cells.
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Affiliation(s)
- Tae Gon Kim
- College of Life Sciences and Biotechnology, Korea University , Seoul , Korea
| | - Young Chol Cho
- College of Life Sciences and Biotechnology, Korea University , Seoul , Korea
| | - Bok-Hwan Chun
- College of Life Sciences and Biotechnology, Korea University , Seoul , Korea
| | - Sung Hyo Park
- College of Life Sciences and Biotechnology, Korea University , Seoul , Korea
| | - Hoi-Seon Lee
- College of Agriculture and Life Science, Chonbuk National University , Jeonju , Korea
| | - Namhyun Chung
- College of Life Sciences and Biotechnology, Korea University , Seoul , Korea
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21
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Townsend D, Yasuda S, Metzger J. Cardiomyopathy of Duchenne muscular dystrophy: pathogenesis and prospect of membrane sealants as a new therapeutic approach. Expert Rev Cardiovasc Ther 2014; 5:99-109. [PMID: 17187461 DOI: 10.1586/14779072.5.1.99] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Duchenne muscular dystrophy (DMD) is a devastating progressive disease of striated muscle deterioration. This fatal X-linked disorder results from the loss of the protein dystrophin, which in turn causes striated muscle membrane instability. Cardiac dysfunction is a growing problem in patients with DMD, but relatively little is known about the pathophysiology of the dystrophic heart. At present, there is no effective treatment for DMD and the current clinical approaches are primarily supportive in nature. This review will discuss the pathogenesis of DMD in the heart and discuss how these pathogenic processes have led to a new class of agents directed specifically at restoring membrane integrity to dystrophic myocardium. The tri-block poloxamers, specifically poloxamer 188 (P188), are able to stabilize the membranes of dystrophic myocardium in animal models and may offer a new therapeutic approach for cardiac disease in DMD.
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Affiliation(s)
- DeWayne Townsend
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA.
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22
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Natsume T, Yoshimoto M. A Method To Estimate the Average Shear Rate in a Bubble Column Using Liposomes. Ind Eng Chem Res 2013. [DOI: 10.1021/ie402874q] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tomotaka Natsume
- Department
of Applied Molecular
Bioscience, Yamaguchi University, 2-16-1 Tokiwadai, Ube, 755-8611, Japan
| | - Makoto Yoshimoto
- Department
of Applied Molecular
Bioscience, Yamaguchi University, 2-16-1 Tokiwadai, Ube, 755-8611, Japan
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23
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Taşlı PN, Yalvaç ME, Sofiev N, Şahin F. Effect of F68, F127, and P85 Pluronic Block Copolymers on Odontogenic Differentiation of Human Tooth Germ Stem Cells. J Endod 2013; 39:1265-71. [DOI: 10.1016/j.joen.2013.06.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 05/15/2013] [Accepted: 06/29/2013] [Indexed: 11/28/2022]
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24
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Effect of F68 on Cryopreservation of Mesenchymal Stem Cells Derived from Human Tooth Germ. Appl Biochem Biotechnol 2013; 171:1819-31. [DOI: 10.1007/s12010-013-0472-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Accepted: 08/22/2013] [Indexed: 11/26/2022]
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25
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Sieblist C, Jenzsch M, Pohlscheidt M. Influence of pluronic F68 on oxygen mass transfer. Biotechnol Prog 2013; 29:1278-88. [PMID: 23843368 DOI: 10.1002/btpr.1770] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 05/27/2013] [Accepted: 05/17/2013] [Indexed: 11/09/2022]
Abstract
Pluronic F68 is one of the most used shear protecting additives in cell culture cultivations. It is well known from literature that such surface-active surfactants lower the surface tension at the gas-liquid interface, which influences the mass transfer. In this study, the effect of Pluronic F68 on oxygen mass transfer in aqueous solutions was examined. Therefore, the gassing in/gassing out method and bubble size measurements were used. At low concentrations of 0.02 g/L, a 50% reduction on mass transfer was observed for all tested spargers and working conditions. An explanation of the observed effects by means of Higbie's penetration or Dankwerts surface renewal theory was applied. It could be demonstrated that the suppressed movement of the bubble surface layer is the main cause for the significant drop down of the kL a-values. For Pluronic F68 concentrations above 0.1 g/L, it was observed that it comes to changes in bubble appearance and bubble size strongly dependent on the sparger type. By using the bubble size measurement data, it could be shown that only small changes in mass transfer coefficient (kL ) take place above the critical micelle concentration. Further changes on overall mass transfer at higher Pluronic F68 concentrations are mainly based on increasing of gas holdup and, more importantly, by increasing of the surface area available for mass transfer.
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Affiliation(s)
- Christian Sieblist
- Pharmaceutical Biotech Production, Roche Diagnostics GmbH, Penzberg, Germany
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26
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Tait AS, Tarrant RDR, Velez-Suberbie ML, Spencer DIR, Bracewell DG. Differential response in downstream processing of CHO cells grown under mild hypothermic conditions. Biotechnol Prog 2013; 29:688-96. [PMID: 23636936 PMCID: PMC3738919 DOI: 10.1002/btpr.1726] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 03/12/2013] [Indexed: 11/16/2022]
Abstract
The manufacture of complex therapeutic proteins using mammalian cells is well established, with several strategies developed to improve productivity. The application of sustained mild hypothermic conditions during culture has been associated with increases in product titer and improved product quality. However, despite associated cell physiological effects, very few studies have investigated the impact on downstream processing (DSP). Characterization of cells grown under mild hypothermic conditions demonstrated that the stationary phase was prolonged by delaying the onset of apoptosis. This enabled cells to maintain viability for extended periods and increase volumetric productivity from 0.74 to 1.02 g L−1. However, host cell proteins, measured by ELISA, increased by ∼50%, attributed to the extended time course and higher peak and harvest cell densities. The individual components making up this impurity, as determined by SELDI-TOF MS and 2D-PAGE, were shown to be largely comparable. Under mild hypothermic conditions, cells were less shear sensitive than those maintained at 37°C, enhancing the preliminary primary recovery step. Adaptive changes in membrane fluidity were further investigated by adopting a pronounced temperature shift immediately prior to primary recovery and the improvement observed suggests that such a strategy may be implementable when shear sensitivity is of concern. Early and late apoptotic cells were particularly susceptible to shear, at either temperature, even under the lowest shear rate investigated. These findings demonstrate the importance of considering the impact of cell culture strategies and cell physiology on DSP, by implementing a range of experimental methods for process characterization. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:688–696, 2013
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Affiliation(s)
- Andrew S Tait
- Dept. of Biochemical Engineering, Advanced Centre for Biochemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK
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27
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Velez-Suberbie ML, Tarrant RDR, Tait AS, Spencer DIR, Bracewell DG. Impact of aeration strategy on CHO cell performance during antibody production. Biotechnol Prog 2012; 29:116-26. [PMID: 23074084 DOI: 10.1002/btpr.1647] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 10/12/2012] [Indexed: 12/20/2022]
Abstract
Stirred tank bioreactors using suspension adapted mammalian cells are typically used for the production of complex therapeutic proteins. The hydrodynamic conditions experienced by cells within this environment have been shown to directly impact growth, productivity, and product quality and therefore an improved understanding of the cellular response is critical. Here we investigate the sub-lethal effects of different aeration strategies on Chinese hamster ovary cells during monoclonal antibody production. Two gas delivery systems were employed to study the presence and absence of the air-liquid interface: bubbled direct gas sparging and a non-bubbled diffusive silicone membrane system. Additionally, the effect of higher gas flow rate in the sparged bioreactor was examined. Both aeration systems were run using chemically defined media with and without the shear protectant Pluronic F-68 (PF-68). Cells were unable to grow with direct gas sparging without PF-68; however, when a silicone membrane aeration system was implemented growth was comparable to the sparged bioreactor with PF-68, indicating the necessity of shear protectants in the presence of bubbles. The cultures exposed to increased hydrodynamic stress were shown by flow cytometry to have decreased F-actin intensity within the cytoskeleton and enter apoptosis earlier. This indicates that these conditions elicit a sub-lethal physiological change in cells that would not be detected by the at-line assays which are normally implemented during cell culture. These physiological changes only result in a difference in continuous centrifugation performance under high flow rate conditions. Product quality was more strongly affected by culture age than the hydrodynamic conditions tested.
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Affiliation(s)
- M Lourdes Velez-Suberbie
- The Advanced Centre of Biochemical Engineering, Dept. of Biochemical Engineering, University College London, Torrington Place, London, WC1E 7JE, U.K
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28
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van der Pol JJ, Machnik M, Biselli M, Portela-Klein T, de Gooijer CD, Tramper J, Wandrey C. On-line immunoanalysis of monoclonal antibodies during a continuous culture of hybridoma cells. Cytotechnology 2012; 24:19-30. [PMID: 22358593 DOI: 10.1023/a:1007913128209] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The monoclonal-antibody production of an immobilized hybridoma cell line cultivated in a fluidized-bed reactor was monitored on-line for nearly 900 h. The monoclonal antibody concentration was determined by an immuno affinity-chromatography method (ABICAP). Antibodies directed against the product, e.g. IgG, were immobilized on a micro-porous gel and packed in small columns. After all IgG present in the sample was bound to the immobilized antibodies, unbound proteins were removed by rinsing the column. Elution of the bound antibodies followed and the antibodies were determined by fluorescence. The analytical procedure was automated with a robotic device to enable on-line measurements. The correlation between the on-line determined data and antibody concentrations measured by HPLC was linear.A sampling system was constructed, which was based on a pneumatically actuated in-line membrane valve integrated into the circulation loop of the reactor. Separation of the cells from the sample stream was achieved by a depth filter made of glass-fibre, situated outside the reactor. Rapid obstruction of the filter by cells or cell debris and contamination of the sample system was avoided by intermittent rinsing of the sample system with a chemical solution. The intermittent rinsing of the filter, which had a surface of 4.8 cm(2), resulted in an operational capacity of up to 40 samples (1.0 l total sample volume). Both the sampling system and the analytical device functioned without failure during this long-term culture.The culture temperature was varied between 34 and 40 °C. Raising the temperature from 34 up to 37 °C resulted in a simultaneous increase of growth and specific antibody production rate. Specific metabolic rates of glucose, lactate, glutamine and ammonium stayed constant in this temperature range. A further enhancement of temperature up to 40 °C had a negative effect on the growth rate, whereas the specific monoclonal antibody production rate showed a small increase. The other specific metabolic rates also increased in the temperature range between 38 to 40 °C.
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Affiliation(s)
- J J van der Pol
- Forschungszentrum Jülich GmbH, Institute of Biotechnology, D-52425, Jülich, Germany
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29
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Wu J. Insights into protective effects of medium additives on animal cells under fluid stresses: the hydrophobic interactions. Cytotechnology 2012; 22:103-9. [PMID: 22358920 DOI: 10.1007/bf00353929] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Animal cells in suspension culture can suffer severe mechanical damage from bursting gas bubbles or other hydrodynamic force sources. Certain chemical additives in the culture media, particularly some surface-active chemicals, can effectively protect animal cells against such damage. Previously we proposed that the protective effect is associated with the adsorption of the additives in the cell membrane through hydrophobic binding of the surface-active molecules to the membrane. Adsorption of the additives to the cell membrane may lead to decreased hydrophobicity of the cell surface, thus eliminating cell adhesion to bubbles and reducing cell damage from bursting bubbles. In this study, we measured the hydrophobicity of two insect cell lines based on cell adhesion to hydrocarbon phase and its influence by surface-active chemicals, Pluronic F68, a methylcellulose and a polyethylene glycol. The experimental results showed strong support for the aforecited cell protection mechanism.
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Affiliation(s)
- J Wu
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Hung Hom, Kowloon, Hong Kong
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30
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Jordan M, Eppenberger HM, Sucker H, Widmer F, Einsele A. Interactions between animal cells and gas bubbles: The influence of serum and pluronic F68 on the physical properties of the bubble surface. Biotechnol Bioeng 2012; 43:446-54. [PMID: 18615740 DOI: 10.1002/bit.260430603] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We describe a method by which the degree of bubble saturation can be determined by measuring the velocity of single bubbles at different heights from the bubble source in pure water containing increasing concentrations of surfactants. The highest rising velocities were measured in pure water. Addition of surfactants caused a concentration-dependent and height-dependent decrease in bubble velocity; thus, bubbles are covered with surfactants as they rise, and the distance traveled until saturation is reached decreases with increased concentration of surfactant. Pluronic F68 is a potent effector of bubble saturation, 500 times more active than serum. At Pluronic F68 concentrations of 0.1% (w/v), bubbles are saturated essentially at their source. The effect of bubble saturation on the interactions between animal cells and gas bubbles was investigated by using light microscopy and a micromanipulator. In the absence of surfactants, bubbles had a killing effect on cells; hybridoma cells and Chinese hamster ovary (CHO) cells were ruptured when coming into contact with a bubble. Bubbles only partially covered by surfactants adsorbed the cells. The adsorbed cells were not damaged and they also could survive subsequent detachment. Saturated bubbles, on the other hand, did not show any interactions with cells. It is concluded that the protective effect of serum and Pluronic F68 in sparged cultivation systems is based on covering the medium-bubble interface with surfaceactive components and that cell death occurs either after contact of cells with an uncovered bubble or by adsorption of cells through partially saturated bubbles and subsequent transport of cells into the foam region. (c) 1994 John Wiley & Sons, Inc.
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Affiliation(s)
- M Jordan
- Institute for Cell Biology, Swiss Federal Institute of Technology (ETH) 8093 Zürich, Switzerland
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31
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Michaels JD, Nowak JE, Mallik AK, Koczo K, Wasan DT, Papoutsakis ET. Analysis of cell-to-bubble attachment in sparged bioreactors in the presence of cell-protecting additives. Biotechnol Bioeng 2012; 47:407-19. [PMID: 18623417 DOI: 10.1002/bit.260470402] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
To investigate the mechanisms of cell protection provided by medium additives against animal cell injury in sparged bioreactors, we have analyzed the effect of various additives on the cell-to-bubble attachment process using CHO cells in suspension. Cell-to-bubble attachment was examined using three experimental techniques: (1) cell-bubble induction time analysis (cell-to-bubble attachment times); (2) forming thin liquid films and observing the movement and location of cells in the thin films; and (3) foam flotation experiments. The induction times we measured for the various additives are as follows: no additive (50 to 500 ms), polyvinyl pyrrolidone (PVP: 20 to 500 ms), polyethylene glycol (PEG: 200 to 1000 ms), 3% serum (500 to 1000 ms), polyvinyl alcohol (PVA: 2 to 10 s), Pluronic F68 (5 to 20 s), and Methocel (20 to 60 s). In the thin film formation experiments, cells in medium with either F68, PVA, or Methocel quickly flowed out of draining thin liquid films and entered the plateau border. When using media with no additive or with serum, the flow of cells out of the thin liquid film and film drainage were slower than for media containing Pluronic F68. PVA, or Methocel. With PVP and PEG, the thin film drainage was much slower and cells remained trapped in the film. For the foam flotation experiments, a separation factor (ratio of cell concentration in the foam catch to that in the bubble column) was determined for the various additives. In the order of increasing separation factors (i.e., increasing cell attachment to bubbles), the additives are as follows: Methocel, PVA, Pluronic F68, 3% serum, serum-free medium with no additives, PEG, and PVP. Based on the results of these three different cell-to-bubble attachment experiments, we have classified the cell-protecting additives into three groups: (1) Pluronic F68, PVA, and Methocel (reduced cell-to-bubble attachment); (2) PEG and PVP (high or increased cell-to-bubble attachment); and (3) FBS (reduced cell attachment butslower drainage films compared with F68, PVA, and Methocel with some cell entrapment in those films). These phenomena are discussed in relation to the interfacial properties of the media reported in a companion Study (this issue). (c) 1995 John Wiley & Sons Inc.
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Affiliation(s)
- J D Michaels
- Department of Chemical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3120
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32
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Poly-γ-glutamic acid enhances the growth and viability of Chinese hamster ovary cells in serum-free medium. Biotechnol Lett 2012; 34:1807-10. [DOI: 10.1007/s10529-012-0982-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 05/29/2012] [Indexed: 10/28/2022]
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33
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Wurm M, Zeng AP. Mechanical disruption of mammalian cells in a microfluidic system and its numerical analysis based on computational fluid dynamics. LAB ON A CHIP 2012; 12:1071-1077. [PMID: 22311121 DOI: 10.1039/c2lc20918g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The lysis of mammalian cells is an essential part of different lab-on-a-chip sample preparation methods, which aim at the release, separation, and subsequent analysis of DNA, proteins, or metabolites. Particularly for the analysis of compartmented in vivo metabolism of mammalian cells, such a method must be very fast compared to the metabolic turnover-rates, it should not affect the native metabolite concentrations, and should ideally leave cell organelles undamaged. So far, no such a method is available. We have developed a microfluidic system for the effective rapid mechanical cell disruption and established a mathematical model to describe the efficiency of the system. Chinese hamster ovary (CHO) cells were disrupted with high efficiency by passing through two consecutive micronozzle arrays. Simultaneous cell compression and shearing led to a disruption rate of ≥90% at a sample flow rate of Q = 120 μL min(-1) per nozzle passage, which corresponds to a mean fluid velocity of 13.3 m s(-1) and a mean Reynolds number of 22.6 in the nozzle gap. We discussed the problem of channel clogging by cellular debris and the resulting flow instability at the micronozzle arrays. The experimental results were compared to predictions from Computational Fluid Dynamics (CFD) simulations and the critical energy dissipation rate for the disruption of the CHO cell population with known size distribution was determined to be 4.7 × 10(8) W m(-3). Our model for the calculation of cell disruption on the basis of CFD-data could be applied to other microgeometries to predict intended disruption or undesired cell damage.
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Affiliation(s)
- Matthias Wurm
- Hamburg University of Technology, Institute of Bioprocess and Biosystems Engineering, Hamburg, Germany
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34
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Gallardo-Rodríguez JJ, García-Camacho F, Sánchez-Mirón A, López-Rosales L, Chisti Y, Molina-Grima E. Shear-induced changes in membrane fluidity during culture of a fragile dinoflagellate microalga. Biotechnol Prog 2011; 28:467-73. [PMID: 22034201 DOI: 10.1002/btpr.737] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 09/21/2011] [Indexed: 12/29/2022]
Abstract
The commonly used shear protective agent Pluronic F68 (PF68) was toxic to the marine dinoflagellate microalga Protoceratium reticulatum, but had a shear-protective effect on it at concentrations of ≤ 0.5 g L(-1) . Supplementation of P. reticulatum cultures with PF68 actually increased the fluidity of the cell membrane; therefore, the shear protective effect of PF68 could not be ascribed to reduced membrane fluidity, an explanation that has been commonly used in relation to its shear protective effect on animal cells. Data are reported on the membrane fluidity of P. reticulatum and its response to the presence of PF68 under sublethal and lethal turbulence regimens. The membrane fluidity was found to depend strongly on the level of lipoperoxides in the cells produced under lethal agitation.
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35
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Hu W, Berdugo C, Chalmers JJ. The potential of hydrodynamic damage to animal cells of industrial relevance: current understanding. Cytotechnology 2011; 63:445-60. [PMID: 21785843 PMCID: PMC3176934 DOI: 10.1007/s10616-011-9368-3] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2008] [Accepted: 06/11/2011] [Indexed: 11/25/2022] Open
Abstract
Suspension animal cell culture is now routinely scaled up to bioreactors on the order of 10,000 L, and greater, to meet commercial demand. However, the concern of the 'shear sensitivity' of animal cells still remains, not only within the bioreactor, but also in the downstream processing. As the productivities continue to increase, titer of ~10 g/L are now reported with cell densities greater than 2 × 10(7) cells/mL. Such high, and potentially higher cell densities will inevitably translate to increased demand in mass transfer and mixing. In addition, achieving productivity gains in both the upstream stage and downstream processes can subject the cells to aggressive environments such as those involving hydrodynamic stresses. The perception of 'shear sensitivity' has historically put an arbitrary upper limit on agitation and aeration in bioreactor operation; however, as cell densities and productivities continue to increase, mass transfer requirements can exceed those imposed by these arbitrary low limits. Therefore, a better understanding of how animal cells, used to produce therapeutic products, respond to hydrodynamic forces in both qualitative and quantitative ways will allow an experimentally based, higher, "upper limit" to be created to guide the design and operation of future commercial, large scale bioreactors. With respect to downstream hydrodynamic conditions, situations have already been achieved in which practical limits with respect to hydrodynamic forces have been experienced. This review mainly focuses on publications from both the academy and industry regarding the effect of hydrodynamic forces on industrially relevant animal cells, and not on the actual scale-up of bioreactors. A summary of implications and remaining challenges will also be presented.
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Affiliation(s)
- Weiwei Hu
- Cell Culture Development, Biogen Idec Inc., 5000 Davis Drive, RTP, NC 27709 USA
| | - Claudia Berdugo
- Scientist / Research & Development, BD Biosciences, 54 Loveton Circle, Sparks, MD 21152 USA
| | - Jeffrey J. Chalmers
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, 140 West 19th Ave., Columbus, OH 43210 USA
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36
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Butler M, Huzel N, Barnabé N, Gray T, Bajno L. Linoleic acid improves the robustness of cells in agitated cultures. Cytotechnology 2011; 30:27-36. [PMID: 19003353 DOI: 10.1023/a:1008048126055] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The murine hybridoma (CC9C10) was subjected to high shear rates in a spinner flask to determine the effect of various culture additives on cell survival. At 500 rpm, the half-life of the viable cell concentration in a low protein serum-free medium was 50 min. Both bovine serum albumin and Pluronic F-68 had a significant effect in protecting cells under these conditions. The effects of the two supplements were additive, so that in the presence of both supplements there was minimal cell damage at 500 rpm. The survival rate of cells grown in media supplemented with linoleic acid improved significantly under high stirring rates. Cells grown for one passage in 50 muM linoleic acid and stirred at 500 rpm had a significantly higher survival rate than control cells. For cells grown over 5 passages in 25 muM linoleic acid, the survival rate at 470 rpm was x3 greater than that determined for control cells. This difference gradually decreased at higher stirring rates up to 610 rpm when the half-life of the viable cell population was reduced to approximately 10 min. Supplementation of cultures with linoleic acid has previously been shown to result in incorporation into all three cellular lipid fractions - polar, non-polar and free fatty acid (Butler et al., 1997). Our explanation for the increased survivability of the cells at high agitation rates in the presence of linoleic acid is that the structural lipid components of the cell including the outer membrane attained a higher unsaturated/saturated ratio which was more robust than that of control cells.
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Affiliation(s)
- M Butler
- Department of Microbiology, University of Manitoba, Winnipeg, R3T 2N2, Canada
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Chung HH, Zhou C, Khor HK, Qiu J. Direct determination of residual Pluronic F-68 in in-process samples from monoclonal antibody preparations by high performance liquid chromatography. J Chromatogr A 2011; 1218:2106-13. [DOI: 10.1016/j.chroma.2010.12.073] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Revised: 12/16/2010] [Accepted: 12/16/2010] [Indexed: 11/30/2022]
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38
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Clincke MF, Guedon E, Yen FT, Ogier V, Roitel O, Goergen JL. Effect of surfactant pluronic F-68 on CHO cell growth, metabolism, production, and glycosylation of human recombinant IFN-γ in mild operating conditions. Biotechnol Prog 2010; 27:181-90. [PMID: 21312365 DOI: 10.1002/btpr.503] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 06/24/2010] [Indexed: 11/11/2022]
Abstract
The control of glycosylation to satisfy regulatory requirements and quality consistency of recombinant proteins produced by different processes has become an important issue. With two N-glycosylation sites, γ-interferon (IFN-γ) can be seen as a prototype of a recombinant therapeutic glycoprotein for this purpose. The effect of the nonionic surfactant Pluronic F-68 (PF-68) on cell growth and death was investigated, as well as production and glycosylation of recombinant IFN-γ produced by a CHO cell line that was maintained in a rich protein-free medium in the absence or presence of low agitation. Under these conditions, a dose-dependent effect of PF-68 (0-0.1%) was shown not only to significantly enhance growth but also to reduce cell lysis. Interestingly, supplementing the culture medium with PF-68 led to increased IFN-γ production as a result of both higher cell densities and a higher specific production rate of IFN-γ. If cells were grown with agitation, lack of PF-68 in the culture medium decreased the fraction of the fully glycosylated IFN-γ glycoform (2N) from 80% to 65-70% during the initial period. This effect appeared to be due to a lag phase in cell growth observed during this period. Finally, a global kinetic study of CHO cell metabolism indicated higher efficiency in the utilization of the two major carbon substrates when cultures were supplemented with PF-68. Therefore, these results highlight the importance of understanding how media surfactant can affect cell growth as well as cell death and the product quality of a recombinant glycoprotein expressed in CHO cell cultures.
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Affiliation(s)
- Marie-Françoise Clincke
- Laboratoire Réactions et Génie des Procédés, UPR-CNRS 3349, ENSAIA-INPL, Nancy Université, Vandoeuvre-lès-Nancy, France
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Chuppa S, Tsai YS, Yoon S, Shackleford S, Rozales C, Bhat R, Tsay G, Matanguihan C, Konstantinov K, Naveh D. Fermentor temperature as a tool for control of high-density perfusion cultures of mammalian cells. Biotechnol Bioeng 2010; 55:328-38. [PMID: 18636491 DOI: 10.1002/(sici)1097-0290(19970720)55:2<328::aid-bit10>3.0.co;2-d] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Temperature is a key environmental variable whose potential in animal cell fermentor optimization is not yet fully utilized. The scarce literature data suggests that reduced fermentor temperature results in an improved viability and shear resistance, higher cell density and titer in batch cultures, and reduction in glucose/lactate metabolism. Due to the arrest of the cells in the G1 phase, the specific growth rate was found to decrease at temperatures below 37.0 degrees C. The response of the specific production rate was cell line dependent: in some cases it increased 2-to-3-fold, but decreased in other cases. The controlable slowdown of cell metabolism at lower temperature can be used in optimization of perfusion mammalian cell cultures with several potential advantages, including higher cell density in oxygen limited reactors, lower perfusion rate, improved product quality, simplified pH control, and others. To evaluate this strategy, a series of long-term experiments in 15 L perfusion bioreactors culturing recombinant hamster cells at 20.0 x 10(6) cells/mL were conducted. The temperature was changed over a range of set points, and maintained at each of these for a long period of time. Steady state process data was collected and analyzed. The effect of temperature on the following characteristics of the perfusion process was studied: cell growth, glucose/lactate metabolism, glutamine/ammonia metabolism, cell respiration, cell density at constant oxygen transfer rate, proteolytic activity, and product quality (glycosylation and molecule fragmentation). The results suggest that temperature is a variable with a significant potential in optimization of perfusion cultures. Properly selected temperature set point will contribute to the overall improvement of process performance. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 328-338, 1997.
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Affiliation(s)
- S Chuppa
- Bayer Corp., 800 Dwight Way, P.O. Box 1986, Berkeley, California 94710; telephone: (510) 705-7327; fax: (510) 705-4911
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40
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Challenges for the production of virus-like particles in insect cells: The case of rotavirus-like particles. Biochem Eng J 2009. [DOI: 10.1016/j.bej.2009.02.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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41
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Clarke MSF, Pritchard KA, Medow MS, McNeil PL. An Atherogenic Level of Native LDL Increases Endothelial Cell Vulnerability to Shear-Induced Plasma Membrane Wounding and Consequent Release of Basic Fibroblast Growth Factor. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/10623329609024689] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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42
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Vaccine against infectious bovine keratoconjunctivitis: A new approach to optimize the production of highly piliated Moraxella bovis cells. Vaccine 2008; 26:6542-9. [DOI: 10.1016/j.vaccine.2008.09.059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Accepted: 09/17/2008] [Indexed: 11/23/2022]
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Tharmalingam T, Ghebeh H, Wuerz T, Butler M. Pluronic enhances the robustness and reduces the cell attachment of mammalian cells. Mol Biotechnol 2008; 39:167-77. [PMID: 18327558 DOI: 10.1007/s12033-008-9045-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The addition of the non-ionic surfactant, Pluronic F-68, to serum-free CHO cultures causes multi-functional effects that enhance cell yield in agitated cultures and reduce cell adhesion in stationary cultures. Three independent CHO cell lines were subjected to high liquid shear in assay systems that either included or excluded a liquid-gas interface. In the absence of Pluronic, there was a loss in cell viability in either assay system, although there was an intrinsic variability in sensitivity of the cell lines to shear damage. Supplementation with Pluronic prevented loss of cell viability, indicating protection in either a gas sparged or bubble-free environment. However, we found no evidence of long-term protection of cells once Pluronic was removed. Pluronic was capable of repairing trypsin-damaged cells as evidenced by enhanced growth, reduced membrane porosity, and improved robustness under liquid shear. The proportion of adherent cells was reduced to a minimal level by the presence of Pluronic although its effect was rapidly reversible with a high proportion (70%) of adherent cells observed within a few culture passages of its removal. The observed effects of Pluronic on these cultures are compatible with a mechanism in which the polymer forms a protective layer on the cell membrane, which has a significantly lower hydrophobicity.
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Affiliation(s)
- T Tharmalingam
- Department of Microbiology, University of Manitoba, Manitoba, Winnipeg, Canada R3T 2N2
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Gigout A, Buschmann MD, Jolicoeur M. The fate of Pluronic F-68 in chondrocytes and CHO cells. Biotechnol Bioeng 2008; 100:975-87. [DOI: 10.1002/bit.21840] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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45
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Lara AR, Galindo E, Ramírez OT, Palomares LA. Living with heterogeneities in bioreactors: understanding the effects of environmental gradients on cells. Mol Biotechnol 2007; 34:355-81. [PMID: 17284782 DOI: 10.1385/mb:34:3:355] [Citation(s) in RCA: 250] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 01/14/2023]
Abstract
The presence of spatial gradients in fundamental culture parameters, such as dissolved gases, pH, concentration of substrates, and shear rate, among others, is an important problem that frequently occurs in large-scale bioreactors. This problem is caused by a deficient mixing that results from limitations inherent to traditional scale-up methods and practical constraints during large-scale bioreactor design and operation. When cultured in a heterogeneous environment, cells are continuously exposed to fluctuating conditions as they travel through the various zones of a bioreactor. Such fluctuations can affect cell metabolism, yields, and quality of the products of interest. In this review, the theoretical analyses that predict the existence of environmental gradients in bioreactors and their experimental confirmation are reviewed. The origins of gradients in common culture parameters and their effects on various organisms of biotechnological importance are discussed. In particular, studies based on the scale-down methodology, a convenient tool for assessing the effect of environmental heterogeneities, are surveyed.
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Affiliation(s)
- Alvaro R Lara
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología Universidad Nacional Autónoma de México (UNAM), Apdo. Postal. 510-3. Cuernavaca, Morelos, CP. 62250, México
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Gong YW, Li SY, Han RB, Yuan YJ. Age-related responses of suspension cultured Taxus cuspidata to hydrodynamic shear stress. Biochem Eng J 2006. [DOI: 10.1016/j.bej.2006.09.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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47
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Reactor engineering in large scale animal cell culture. Cytotechnology 2006; 50:9-33. [PMID: 19003068 DOI: 10.1007/s10616-006-9005-8] [Citation(s) in RCA: 205] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Accepted: 03/29/2006] [Indexed: 10/24/2022] Open
Abstract
This article mainly addresses the issues associated with the engineering of large-scale free suspension culture in agitated bioreactors >10,000 L because they have become the system of choice industrially. It is particularly concerned with problems that become increasingly important as the scale increases. However, very few papers have been written that are actually based on such large-scale studies and the few that do rarely address any of the issues quantitatively. Hence, it is necessary very often to extrapolate from small-scale work and this review tries to pull the two types of study together. It is shown that 'shear sensitivity' due to agitation and bursting bubbles is no longer considered a major problem. Homogeneity becomes increasingly important with respect to pH and nutrients at the largest scale and sub-surface feeding is recommended despite 'cleaning in place' concerns. There are still major questions with cell retention/recycle systems at these scales, either because of fouling, of capacity or of potential and different 'shear sensitivity' questions. Fed-batch operation gives rise to cell densities that have led to the use of oxygen and enriched air to meet oxygen demands. This strategy, in turn, gives rise to a CO(2) evolution rate that impacts on pH control, pCO(2) and osmolality. These interactions are difficult to resolve but if higher sparge and agitation intensities could be used to achieve the necessary oxygen transfer, the problem would largely disappear. Thus, the perception of 'shear sensitivity' is still impacting on the development of animal cell culture at the commercial scale. Microcarrier culture is also briefly addressed. Finally, some recommendations for bioreactor configuration and operating strategy are given.
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Camacho FG, Belarbi E, García MC, Mirón AS, Chile T, Chisti Y, Grima EM. Shear effects on suspended marine sponge cells. Biochem Eng J 2005. [DOI: 10.1016/j.bej.2005.04.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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49
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Huhtala A, Linko P, Mutharasan R. Protein response of insect cells to bioreactor environmental stresses. J Biotechnol 2005; 118:278-89. [PMID: 16002170 DOI: 10.1016/j.jbiotec.2005.05.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2004] [Revised: 04/29/2005] [Accepted: 05/04/2005] [Indexed: 01/23/2023]
Abstract
Protein expression of Spodoptera frugiperda (Sf9) insect cells was characterized upon exposure to environmental stresses typically present in bioreactors including heat shock, oxygen deprivation, shear stress, change of pH, and salinity or ethanol shock. This study fills the void in knowledge as to how bioreactor hydrodynamics, anoxia, small changes in pH as well as salinity alterations due to pH control or exposure to ethanol used in asepsis treatments affect protein expression in Sf9 cells. Heat shock at 43 degrees C induced proteins at 83 kDa, 68-78 kDa and six small heat shock proteins (hsps) at 23-15.5 kDa. Anaerobic conditions in CO2 atmosphere reduced significantly the normal protein synthesis and induced a small subset of heat shock proteins at 70 kDa. Oxygen deprivation in nitrogen atmosphere transiently induces the 70 kDa proteins and had minor effects on the normal protein synthesis. Exposure to increased salinity or ethanol concentration failed to trigger the stress response, but may extensively inhibit the induction of normal proteins even though there was a negligible change in cell viability. Shear stress that had a major reducing effect on cell viability did not change the protein synthesis profile of Sf9 cells. Both long and short term exposures to small pH changes had negligible effects on protein synthesis.
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Affiliation(s)
- Anne Huhtala
- Department of Chemical Technology, Helsinki University of Technology, P.O. Box 6100, FIN-02150 HUT, Finland
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50
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Shi X, Karkut T, Alting-Mees M, Chamankhah M, Hemmingsen SM, Hegedus DD. Enhancing Escherichia coli electrotransformation competency by invoking physiological adaptations to stress and modifying membrane integrity. Anal Biochem 2003; 320:152-5. [PMID: 12895481 DOI: 10.1016/s0003-2697(03)00352-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Xianzong Shi
- Agriculture and Agri-Food Canada, Saskatoon, Sask., Canada S7N 0X2
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