The Experts below are selected from a list of 144 Experts worldwide ranked by ideXlab platform
Mike Hoare - One of the best experts on this subject based on the ideXlab platform.
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An ultra scale‐down characterization of low shear stress primary recovery stages to enhance selectivity of fusion protein recovery from its molecular variants
Biotechnology and bioengineering, 2013Co-Authors: Eduardo C. Lau, Simyee Kong, Ann Mcilgorm, Kate A. Dalton, Shaun Mcnulty, Claire Entwisle, Mike HoareAbstract:Fusion proteins offer the prospect of new therapeutic products with multiple functions. The primary recovery is investigated of a fusion protein consisting of modified E2 protein from hepatitis C virus fused to human IgG1 Fc and expressed in a Chinese hamster ovary (CHO) cell line. Fusion protein products inevitably pose increased challenge in preparation and purification. Of particular concerns are: (i) the impact of shear stress on product integrity and (ii) the presence of product-related contaminants which could prove challenging to remove during the high resolution purification steps. This paper addresses the use of microwell-based ultra scale-down (USD) methods to develop a bioprocess strategy focused on the integration of cell culture and cell removal operations and where the focus is on the use of operations which impart low shear stress levels even when applied at eventual manufacturing scale. An USD shear device was used to demonstrate that cells exposed to high process stresses such as those that occur in the Feed Zone of a continuous non-hermetic centrifuge resulted in the reduction of the fusion protein and also the release of glycosylated intracellular variants. In addition, extended cell culture resulted in release of such variants. USD mimics of low shear stress, hydrohermetic Feed Zone centrifugation and of depth filtration were used to demonstrate little to no release during recovery of these variants with both results verified at pilot scale. Furthermore, the USD studies were used to predict removal of contaminants such as lipids, nucleic acids, and cell debris with, for example, depth filtration delivering greater removal than for centrifugation but a small (~10%) decrease in yield of the fusion protein. These USD observations of product recovery and carryover of contaminants were also confirmed at pilot scale as was also the capacity or throughput achievable for continuous centrifugation or for depth filtration. The advantages are discussed of operating a lower yield cell culture and a low shear stress recovery process in return for a considerably less challenging purification demand.
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Shear stress analysis of mammalian cell suspensions for prediction of industrial centrifugation and its verification.
Biotechnology and bioengineering, 2006Co-Authors: Nick Hutchinson, Suzanne S. Farid, N. Bingham, N. Murrell, Mike HoareAbstract:This article describes the use of ultra scale-down studies requiring milliliter quantities of process material to study the clarification of mammalian cell culture broths using industrial-scale continuous centrifuges during the manufacture of a monoclonal antibody for therapeutic use. Samples were pretreated in a small high-speed rotating-disc device in order to mimic the effect on the cells of shear stresses in the Feed Zone of the industrial scale centrifuges. The use of this Feed mimic was shown to predict a reduction of the clarification efficiency by significantly reducing the particle size distribution of the mammalian cells. The combined use of the rotating-disc device and a laboratory-scale test tube centrifuge successfully predicted the separation characteristics of industrial-scale, disc stack centrifuges operating with different Feed Zones. A 70% reduction in flow rate in the industrial-scale centrifuge was shown to arise from shear effects. A predicted 2.5-fold increase in throughput for the same clarification performance, achieved by the change to a centrifuge using a Feed Zone designed to give gentler acceleration of the bioprocess fluid, was also verified at large-scale.
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Performance prediction of industrial centrifuges using scale-down models
Bioprocess and Biosystems Engineering, 2003Co-Authors: M. Boychyn, J. More, Martin Bulmer, Daniel G. Bracewell, Mike HoareAbstract:Computational fluid dynamics was used to model the high flow forces found in the Feed Zone of a multichamber-bowl centrifuge and reproduce these in a small, high-speed rotating disc device. Linking the device to scale-down centrifugation, permitted good estimation of the performance of various continuous-flow centrifuges (disc stack, multichamber bowl, CARR Powerfuge TM) for shear-sensitive protein precipitates. Critically, the ultra scale-down centrifugation process proved to be a much more accurate predictor of production multichamber-bowl performance than was the pilot centrifuge.
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Characterization of flow intensity in continuous centrifuges for the development of laboratory mimics
Chemical Engineering Science, 2001Co-Authors: M. Boychyn, J. More, Martin Bulmer, P. Ayazi Shamlou, Mike HoareAbstract:Predicting the recovery of “delicate” biological materials by centrifugation using laboratory centrifuges has been a major challenge to biochemical engineers partly because of the difficulty in accurately quantifying the shear stresses in continuous-flow industrial centrifuges and partly because the clarification and dewatering conditions in the laboratory units do not represent those occurring in industrial centrifuges. In this paper, the flow field in the Feed Zone of an industrial multichamber-bowl centrifuge is mapped and its profile of energy dissipation rate established using computational fluid dynamics (CFD). A small high-speed rotating-disc device is designed with the capacity to reproduce the CFD-predicted energy dissipation rates in the Feed Zone. Milliliter quantities of the process material are shear-treated in the device operating at a speed that mimics the local critical flow conditions in the industrial centrifuge. The results are used to assess the impact of flow conditions in the Feed Zone of the centrifuge on the physical properties of protein precipitates and on their predicted recovery using a laboratory centrifuge. This approach was used to explain the reduction in the performance of the centrifuge from the predicted 88% clarification to the observed 39% clarification of the precipitate particles. The combination of the small high-speed disc device and the laboratory centrifuge is particularly advantageous when dealing with biological products at the early stages of process development for which only small quantities of test material are often available.
Simyee Kong - One of the best experts on this subject based on the ideXlab platform.
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An ultra scale‐down characterization of low shear stress primary recovery stages to enhance selectivity of fusion protein recovery from its molecular variants
Biotechnology and Bioengineering, 2013Co-Authors: Simyee Kong, Ann Mcilgorm, Kate A. Dalton, Shaun Mcnulty, Claire Entwisle, MICHAEL HOAREAbstract:Fusion proteins offer the prospect of new therapeutic products with multiple functions. The primary recovery is investigated of a fusion protein consisting of modified E2 protein from hepatitis C virus fused to human IgG1 Fc and expressed in a Chinese hamster ovary (CHO) cell line. Fusion protein products inevitably pose increased challenge in preparation and purification. Of particular concerns are: (i) the impact of shear stress on product integrity and (ii) the presence of product-related contaminants which could prove challenging to remove during the high resolution purification steps. This paper addresses the use of microwell-based ultra scale-down (USD) methods to develop a bioprocess strategy focused on the integration of cell culture and cell removal operations and where the focus is on the use of operations which impart low shear stress levels even when applied at eventual manufacturing scale. An USD shear device was used to demonstrate that cells exposed to high process stresses such as those that occur in the Feed Zone of a continuous non-hermetic centrifuge resulted in the reduction of the fusion protein and also the release of glycosylated intracellular variants. In addition, extended cell culture resulted in release of such variants. USD mimics of low shear stress, hydrohermetic Feed Zone centrifugation and of depth filtration were used to demonstrate little to no release during recovery of these variants with both results verified at pilot scale. Furthermore, the USD studies were used to predict removal of contaminants such as lipids, nucleic acids, and cell debris with, for example, depth filtration delivering greater removal than for centrifugation but a small (∼10%) decrease in yield of the fusion protein. These USD observations of product recovery and carryover of contaminants were also confirmed at pilot scale as was also the capacity or throughput achievable for continuous centrifugation or for depth filtration. The advantages are discussed of operating a lower yield cell culture and a low shear stress recovery process in return for a considerably less challenging purification demand. Biotechnol. Bioeng. 2013; 110: 1973–1983. © 2013 Wiley Periodicals, Inc.
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An ultra scale‐down characterization of low shear stress primary recovery stages to enhance selectivity of fusion protein recovery from its molecular variants
Biotechnology and bioengineering, 2013Co-Authors: Eduardo C. Lau, Simyee Kong, Ann Mcilgorm, Kate A. Dalton, Shaun Mcnulty, Claire Entwisle, Mike HoareAbstract:Fusion proteins offer the prospect of new therapeutic products with multiple functions. The primary recovery is investigated of a fusion protein consisting of modified E2 protein from hepatitis C virus fused to human IgG1 Fc and expressed in a Chinese hamster ovary (CHO) cell line. Fusion protein products inevitably pose increased challenge in preparation and purification. Of particular concerns are: (i) the impact of shear stress on product integrity and (ii) the presence of product-related contaminants which could prove challenging to remove during the high resolution purification steps. This paper addresses the use of microwell-based ultra scale-down (USD) methods to develop a bioprocess strategy focused on the integration of cell culture and cell removal operations and where the focus is on the use of operations which impart low shear stress levels even when applied at eventual manufacturing scale. An USD shear device was used to demonstrate that cells exposed to high process stresses such as those that occur in the Feed Zone of a continuous non-hermetic centrifuge resulted in the reduction of the fusion protein and also the release of glycosylated intracellular variants. In addition, extended cell culture resulted in release of such variants. USD mimics of low shear stress, hydrohermetic Feed Zone centrifugation and of depth filtration were used to demonstrate little to no release during recovery of these variants with both results verified at pilot scale. Furthermore, the USD studies were used to predict removal of contaminants such as lipids, nucleic acids, and cell debris with, for example, depth filtration delivering greater removal than for centrifugation but a small (~10%) decrease in yield of the fusion protein. These USD observations of product recovery and carryover of contaminants were also confirmed at pilot scale as was also the capacity or throughput achievable for continuous centrifugation or for depth filtration. The advantages are discussed of operating a lower yield cell culture and a low shear stress recovery process in return for a considerably less challenging purification demand.
MICHAEL HOARE - One of the best experts on this subject based on the ideXlab platform.
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An ultra scale‐down characterization of low shear stress primary recovery stages to enhance selectivity of fusion protein recovery from its molecular variants
Biotechnology and Bioengineering, 2013Co-Authors: Simyee Kong, Ann Mcilgorm, Kate A. Dalton, Shaun Mcnulty, Claire Entwisle, MICHAEL HOAREAbstract:Fusion proteins offer the prospect of new therapeutic products with multiple functions. The primary recovery is investigated of a fusion protein consisting of modified E2 protein from hepatitis C virus fused to human IgG1 Fc and expressed in a Chinese hamster ovary (CHO) cell line. Fusion protein products inevitably pose increased challenge in preparation and purification. Of particular concerns are: (i) the impact of shear stress on product integrity and (ii) the presence of product-related contaminants which could prove challenging to remove during the high resolution purification steps. This paper addresses the use of microwell-based ultra scale-down (USD) methods to develop a bioprocess strategy focused on the integration of cell culture and cell removal operations and where the focus is on the use of operations which impart low shear stress levels even when applied at eventual manufacturing scale. An USD shear device was used to demonstrate that cells exposed to high process stresses such as those that occur in the Feed Zone of a continuous non-hermetic centrifuge resulted in the reduction of the fusion protein and also the release of glycosylated intracellular variants. In addition, extended cell culture resulted in release of such variants. USD mimics of low shear stress, hydrohermetic Feed Zone centrifugation and of depth filtration were used to demonstrate little to no release during recovery of these variants with both results verified at pilot scale. Furthermore, the USD studies were used to predict removal of contaminants such as lipids, nucleic acids, and cell debris with, for example, depth filtration delivering greater removal than for centrifugation but a small (∼10%) decrease in yield of the fusion protein. These USD observations of product recovery and carryover of contaminants were also confirmed at pilot scale as was also the capacity or throughput achievable for continuous centrifugation or for depth filtration. The advantages are discussed of operating a lower yield cell culture and a low shear stress recovery process in return for a considerably less challenging purification demand. Biotechnol. Bioeng. 2013; 110: 1973–1983. © 2013 Wiley Periodicals, Inc.
Ann Mcilgorm - One of the best experts on this subject based on the ideXlab platform.
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An ultra scale‐down characterization of low shear stress primary recovery stages to enhance selectivity of fusion protein recovery from its molecular variants
Biotechnology and Bioengineering, 2013Co-Authors: Simyee Kong, Ann Mcilgorm, Kate A. Dalton, Shaun Mcnulty, Claire Entwisle, MICHAEL HOAREAbstract:Fusion proteins offer the prospect of new therapeutic products with multiple functions. The primary recovery is investigated of a fusion protein consisting of modified E2 protein from hepatitis C virus fused to human IgG1 Fc and expressed in a Chinese hamster ovary (CHO) cell line. Fusion protein products inevitably pose increased challenge in preparation and purification. Of particular concerns are: (i) the impact of shear stress on product integrity and (ii) the presence of product-related contaminants which could prove challenging to remove during the high resolution purification steps. This paper addresses the use of microwell-based ultra scale-down (USD) methods to develop a bioprocess strategy focused on the integration of cell culture and cell removal operations and where the focus is on the use of operations which impart low shear stress levels even when applied at eventual manufacturing scale. An USD shear device was used to demonstrate that cells exposed to high process stresses such as those that occur in the Feed Zone of a continuous non-hermetic centrifuge resulted in the reduction of the fusion protein and also the release of glycosylated intracellular variants. In addition, extended cell culture resulted in release of such variants. USD mimics of low shear stress, hydrohermetic Feed Zone centrifugation and of depth filtration were used to demonstrate little to no release during recovery of these variants with both results verified at pilot scale. Furthermore, the USD studies were used to predict removal of contaminants such as lipids, nucleic acids, and cell debris with, for example, depth filtration delivering greater removal than for centrifugation but a small (∼10%) decrease in yield of the fusion protein. These USD observations of product recovery and carryover of contaminants were also confirmed at pilot scale as was also the capacity or throughput achievable for continuous centrifugation or for depth filtration. The advantages are discussed of operating a lower yield cell culture and a low shear stress recovery process in return for a considerably less challenging purification demand. Biotechnol. Bioeng. 2013; 110: 1973–1983. © 2013 Wiley Periodicals, Inc.
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An ultra scale‐down characterization of low shear stress primary recovery stages to enhance selectivity of fusion protein recovery from its molecular variants
Biotechnology and bioengineering, 2013Co-Authors: Eduardo C. Lau, Simyee Kong, Ann Mcilgorm, Kate A. Dalton, Shaun Mcnulty, Claire Entwisle, Mike HoareAbstract:Fusion proteins offer the prospect of new therapeutic products with multiple functions. The primary recovery is investigated of a fusion protein consisting of modified E2 protein from hepatitis C virus fused to human IgG1 Fc and expressed in a Chinese hamster ovary (CHO) cell line. Fusion protein products inevitably pose increased challenge in preparation and purification. Of particular concerns are: (i) the impact of shear stress on product integrity and (ii) the presence of product-related contaminants which could prove challenging to remove during the high resolution purification steps. This paper addresses the use of microwell-based ultra scale-down (USD) methods to develop a bioprocess strategy focused on the integration of cell culture and cell removal operations and where the focus is on the use of operations which impart low shear stress levels even when applied at eventual manufacturing scale. An USD shear device was used to demonstrate that cells exposed to high process stresses such as those that occur in the Feed Zone of a continuous non-hermetic centrifuge resulted in the reduction of the fusion protein and also the release of glycosylated intracellular variants. In addition, extended cell culture resulted in release of such variants. USD mimics of low shear stress, hydrohermetic Feed Zone centrifugation and of depth filtration were used to demonstrate little to no release during recovery of these variants with both results verified at pilot scale. Furthermore, the USD studies were used to predict removal of contaminants such as lipids, nucleic acids, and cell debris with, for example, depth filtration delivering greater removal than for centrifugation but a small (~10%) decrease in yield of the fusion protein. These USD observations of product recovery and carryover of contaminants were also confirmed at pilot scale as was also the capacity or throughput achievable for continuous centrifugation or for depth filtration. The advantages are discussed of operating a lower yield cell culture and a low shear stress recovery process in return for a considerably less challenging purification demand.
Kate A. Dalton - One of the best experts on this subject based on the ideXlab platform.
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An ultra scale‐down characterization of low shear stress primary recovery stages to enhance selectivity of fusion protein recovery from its molecular variants
Biotechnology and Bioengineering, 2013Co-Authors: Simyee Kong, Ann Mcilgorm, Kate A. Dalton, Shaun Mcnulty, Claire Entwisle, MICHAEL HOAREAbstract:Fusion proteins offer the prospect of new therapeutic products with multiple functions. The primary recovery is investigated of a fusion protein consisting of modified E2 protein from hepatitis C virus fused to human IgG1 Fc and expressed in a Chinese hamster ovary (CHO) cell line. Fusion protein products inevitably pose increased challenge in preparation and purification. Of particular concerns are: (i) the impact of shear stress on product integrity and (ii) the presence of product-related contaminants which could prove challenging to remove during the high resolution purification steps. This paper addresses the use of microwell-based ultra scale-down (USD) methods to develop a bioprocess strategy focused on the integration of cell culture and cell removal operations and where the focus is on the use of operations which impart low shear stress levels even when applied at eventual manufacturing scale. An USD shear device was used to demonstrate that cells exposed to high process stresses such as those that occur in the Feed Zone of a continuous non-hermetic centrifuge resulted in the reduction of the fusion protein and also the release of glycosylated intracellular variants. In addition, extended cell culture resulted in release of such variants. USD mimics of low shear stress, hydrohermetic Feed Zone centrifugation and of depth filtration were used to demonstrate little to no release during recovery of these variants with both results verified at pilot scale. Furthermore, the USD studies were used to predict removal of contaminants such as lipids, nucleic acids, and cell debris with, for example, depth filtration delivering greater removal than for centrifugation but a small (∼10%) decrease in yield of the fusion protein. These USD observations of product recovery and carryover of contaminants were also confirmed at pilot scale as was also the capacity or throughput achievable for continuous centrifugation or for depth filtration. The advantages are discussed of operating a lower yield cell culture and a low shear stress recovery process in return for a considerably less challenging purification demand. Biotechnol. Bioeng. 2013; 110: 1973–1983. © 2013 Wiley Periodicals, Inc.
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An ultra scale‐down characterization of low shear stress primary recovery stages to enhance selectivity of fusion protein recovery from its molecular variants
Biotechnology and bioengineering, 2013Co-Authors: Eduardo C. Lau, Simyee Kong, Ann Mcilgorm, Kate A. Dalton, Shaun Mcnulty, Claire Entwisle, Mike HoareAbstract:Fusion proteins offer the prospect of new therapeutic products with multiple functions. The primary recovery is investigated of a fusion protein consisting of modified E2 protein from hepatitis C virus fused to human IgG1 Fc and expressed in a Chinese hamster ovary (CHO) cell line. Fusion protein products inevitably pose increased challenge in preparation and purification. Of particular concerns are: (i) the impact of shear stress on product integrity and (ii) the presence of product-related contaminants which could prove challenging to remove during the high resolution purification steps. This paper addresses the use of microwell-based ultra scale-down (USD) methods to develop a bioprocess strategy focused on the integration of cell culture and cell removal operations and where the focus is on the use of operations which impart low shear stress levels even when applied at eventual manufacturing scale. An USD shear device was used to demonstrate that cells exposed to high process stresses such as those that occur in the Feed Zone of a continuous non-hermetic centrifuge resulted in the reduction of the fusion protein and also the release of glycosylated intracellular variants. In addition, extended cell culture resulted in release of such variants. USD mimics of low shear stress, hydrohermetic Feed Zone centrifugation and of depth filtration were used to demonstrate little to no release during recovery of these variants with both results verified at pilot scale. Furthermore, the USD studies were used to predict removal of contaminants such as lipids, nucleic acids, and cell debris with, for example, depth filtration delivering greater removal than for centrifugation but a small (~10%) decrease in yield of the fusion protein. These USD observations of product recovery and carryover of contaminants were also confirmed at pilot scale as was also the capacity or throughput achievable for continuous centrifugation or for depth filtration. The advantages are discussed of operating a lower yield cell culture and a low shear stress recovery process in return for a considerably less challenging purification demand.