The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Udo Reichl - One of the best experts on this subject based on the ideXlab platform.
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use of sulfated cellulose membrane Adsorbers for chromatographic purification of cell cultured derived influenza a and b viruses
Separation and Purification Technology, 2019Co-Authors: Raquel A Fortuna, Sebastian Van Teeffelen, Adrian Ley, Laura M Fischer, Florian Taft, Yvonne Genzel, Louis Villain, Michael W Wolff, Udo ReichlAbstract:Abstract Influenza virus particles can be purified by pseudo-affinity chromatography using sulfated carbohydrate matrices. In this study, we compared the binding capacity and the purification performance of two bead-based resins and one membrane adsorber for three influenza virus strains (H1N1, H3N2 and B) produced in MDCK suspension cells in a chemically defined medium. The dynamic binding capacity for the sulfated cellulose membrane Adsorbers was consistently higher than for the resins (8 to 22-fold). Confocal microscopy demonstrated, that while virus particles uniformly covered the complete surface of the membrane, the virus particles only bound to the external surface of the sulfated beads. Overall, recovery of virus varied between 66% and 81%. Total protein and DNA removal were >74% and >96%, respectively. Statistically significant differences in the purification performance were more often observed between strains than between matrices. In particular, H3N2 influenza virus particles could only be purified using the sulfated membrane Adsorbers. Due to the higher operating flow rate and binding capacity, the productivity with the membrane Adsorbers was on average 25-times higher than with the resins.
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purification of cell culture derived modified vaccinia ankara virus by pseudo affinity membrane Adsorbers and hydrophobic interaction chromatography
Biotechnology and Bioengineering, 2010Co-Authors: Michael W Wolff, Udo Reichl, C Siewert, S P Hansen, R FaberAbstract:A purification scheme for cell culture-derived smallpox vaccines based on an orthogonal downstream process of pseudo-affinity membrane Adsorbers (MA) and hydrophobic interaction chromatography (HIC) was investigated. The applied pseudo-affinity chromatography, based on reinforced sulfated cellulose and heparin-MA, was optimized in terms of dynamic binding capacities, virus yield and process productivity. HIC was introduced as a subsequent method to further reduce the DNA content. Therefore, two screens were undertaken. First, several HIC ligands were screened for different adsorption behavior between virus particles and DNA. Second, elution from pseudo-affinity MA and adsorption of virus particles onto the hydrophobic interaction matrix was explored by a series of buffers using different ammonium sulfate concentrations. Eventually, variations between different cultivation batches and buffer conditions were investigated.The most promising combination, a sulfated cellulose membrane adsorber with subsequent phenyl HIC resulted in overall virus particle recoveries ranging from 76% to 55% depending on the product batch and applied conditions. On average, 61% of the recovered virus particles were infective within all tested purification schemes and conditions. Final DNA content varied from 0.01% to 2.5% of the starting material and the level of contaminating protein was below 0.1%.
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purification of cell culture derived modified vaccinia ankara virus by pseudo affinity membrane Adsorbers and hydrophobic interaction chromatography
Biotechnology and Bioengineering, 2010Co-Authors: Michael W Wolff, Udo Reichl, C Siewert, S P Hansen, R FaberAbstract:A purification scheme for cell culture-derived smallpox vaccines based on an orthogonal downstream process of pseudo-affinity membrane Adsorbers (MA) and hydrophobic interaction chromatography (HIC) was investigated. The applied pseudo-affinity chromatography, based on reinforced sulfated cellulose and heparin-MA, was optimized in terms of dynamic binding capacities, virus yield and process productivity. HIC was introduced as a subsequent method to further reduce the DNA content. Therefore, two screens were undertaken. First, several HIC ligands were screened for different adsorption behavior between virus particles and DNA. Second, elution from pseudo-affinity MA and adsorption of virus particles onto the hydrophobic interaction matrix was explored by a series of buffers using different ammonium sulfate concentrations. Eventually, variations between different cultivation batches and buffer conditions were investigated.The most promising combination, a sulfated cellulose membrane adsorber with subsequent phenyl HIC resulted in overall virus particle recoveries ranging from 76% to 55% depending on the product batch and applied conditions. On average, 61% of the recovered virus particles were infective within all tested purification schemes and conditions. Final DNA content varied from 0.01% to 2.5% of the starting material and the level of contaminating protein was below 0.1%. Biotechnol. Bioeng. 2010;107: 312–320. © 2010 Wiley Periodicals, Inc.
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sulfated membrane Adsorbers for economic pseudo affinity capture of influenza virus particles
Biotechnology and Bioengineering, 2009Co-Authors: L Opitz, Michael W Wolff, Udo Reichl, S LehmannAbstract:Strategies to control outbreaks of influenza, a contagious respiratory tract disease, are focused mainly on prophylactic vaccinations in conjunction with antiviral medications. Currently, several mammalian cell culture-based influenza vaccine production processes are being established, such as the technologies introduced by Novartis Behring (Optaflu®) or Baxter International Inc. (Celvapan). Downstream processing of influenza virus vaccines from cell culture supernatant can be performed by adsorbing virions onto sulfated column chromatography beads, such as Cellufine® sulfate. This study focused on the development of a sulfated cellulose membrane (SCM) chromatography unit operation to capture cell culture-derived influenza viruses. The advantages of the novel method were demonstrated for the Madin Darby canine kidney (MDCK) cell-derived influenza virus A/Puerto Rico/8/34 (H1N1). Furthermore, the SCM-Adsorbers were compared directly to column-based Cellufine® sulfate and commercially available cation-exchange membrane Adsorbers. Sulfated cellulose membrane Adsorbers showed high viral product recoveries. In addition, the SCM-capture step resulted in a higher reduction of dsDNA compared to the tested cation-exchange membrane Adsorbers. The productivity of the SCM-based unit operation could be significantly improved by a 30-fold increase in volumetric flow rate during adsorption compared to the bead-based capture method. The higher flow rate even further reduced the level of contaminating dsDNA by about twofold. The reproducibility and general applicability of the developed unit operation were demonstrated for two further MDCK cell-derived influenza virus strains: A/Wisconsin/67/2005 (H3N2) and B/Malaysia/2506/2004. Overall, SCM-Adsorbers represent a powerful and economically favorable alternative for influenza virus capture over conventional methods using Cellufine® sulfate. Biotechnol. Bioeng. 2009;103: 1144–1154. © 2009 Wiley Periodicals, Inc.
Michael W Wolff - One of the best experts on this subject based on the ideXlab platform.
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use of sulfated cellulose membrane Adsorbers for chromatographic purification of cell cultured derived influenza a and b viruses
Separation and Purification Technology, 2019Co-Authors: Raquel A Fortuna, Sebastian Van Teeffelen, Adrian Ley, Laura M Fischer, Florian Taft, Yvonne Genzel, Louis Villain, Michael W Wolff, Udo ReichlAbstract:Abstract Influenza virus particles can be purified by pseudo-affinity chromatography using sulfated carbohydrate matrices. In this study, we compared the binding capacity and the purification performance of two bead-based resins and one membrane adsorber for three influenza virus strains (H1N1, H3N2 and B) produced in MDCK suspension cells in a chemically defined medium. The dynamic binding capacity for the sulfated cellulose membrane Adsorbers was consistently higher than for the resins (8 to 22-fold). Confocal microscopy demonstrated, that while virus particles uniformly covered the complete surface of the membrane, the virus particles only bound to the external surface of the sulfated beads. Overall, recovery of virus varied between 66% and 81%. Total protein and DNA removal were >74% and >96%, respectively. Statistically significant differences in the purification performance were more often observed between strains than between matrices. In particular, H3N2 influenza virus particles could only be purified using the sulfated membrane Adsorbers. Due to the higher operating flow rate and binding capacity, the productivity with the membrane Adsorbers was on average 25-times higher than with the resins.
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purification of cell culture derived modified vaccinia ankara virus by pseudo affinity membrane Adsorbers and hydrophobic interaction chromatography
Biotechnology and Bioengineering, 2010Co-Authors: Michael W Wolff, Udo Reichl, C Siewert, S P Hansen, R FaberAbstract:A purification scheme for cell culture-derived smallpox vaccines based on an orthogonal downstream process of pseudo-affinity membrane Adsorbers (MA) and hydrophobic interaction chromatography (HIC) was investigated. The applied pseudo-affinity chromatography, based on reinforced sulfated cellulose and heparin-MA, was optimized in terms of dynamic binding capacities, virus yield and process productivity. HIC was introduced as a subsequent method to further reduce the DNA content. Therefore, two screens were undertaken. First, several HIC ligands were screened for different adsorption behavior between virus particles and DNA. Second, elution from pseudo-affinity MA and adsorption of virus particles onto the hydrophobic interaction matrix was explored by a series of buffers using different ammonium sulfate concentrations. Eventually, variations between different cultivation batches and buffer conditions were investigated.The most promising combination, a sulfated cellulose membrane adsorber with subsequent phenyl HIC resulted in overall virus particle recoveries ranging from 76% to 55% depending on the product batch and applied conditions. On average, 61% of the recovered virus particles were infective within all tested purification schemes and conditions. Final DNA content varied from 0.01% to 2.5% of the starting material and the level of contaminating protein was below 0.1%.
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purification of cell culture derived modified vaccinia ankara virus by pseudo affinity membrane Adsorbers and hydrophobic interaction chromatography
Biotechnology and Bioengineering, 2010Co-Authors: Michael W Wolff, Udo Reichl, C Siewert, S P Hansen, R FaberAbstract:A purification scheme for cell culture-derived smallpox vaccines based on an orthogonal downstream process of pseudo-affinity membrane Adsorbers (MA) and hydrophobic interaction chromatography (HIC) was investigated. The applied pseudo-affinity chromatography, based on reinforced sulfated cellulose and heparin-MA, was optimized in terms of dynamic binding capacities, virus yield and process productivity. HIC was introduced as a subsequent method to further reduce the DNA content. Therefore, two screens were undertaken. First, several HIC ligands were screened for different adsorption behavior between virus particles and DNA. Second, elution from pseudo-affinity MA and adsorption of virus particles onto the hydrophobic interaction matrix was explored by a series of buffers using different ammonium sulfate concentrations. Eventually, variations between different cultivation batches and buffer conditions were investigated.The most promising combination, a sulfated cellulose membrane adsorber with subsequent phenyl HIC resulted in overall virus particle recoveries ranging from 76% to 55% depending on the product batch and applied conditions. On average, 61% of the recovered virus particles were infective within all tested purification schemes and conditions. Final DNA content varied from 0.01% to 2.5% of the starting material and the level of contaminating protein was below 0.1%. Biotechnol. Bioeng. 2010;107: 312–320. © 2010 Wiley Periodicals, Inc.
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sulfated membrane Adsorbers for economic pseudo affinity capture of influenza virus particles
Biotechnology and Bioengineering, 2009Co-Authors: L Opitz, Michael W Wolff, Udo Reichl, S LehmannAbstract:Strategies to control outbreaks of influenza, a contagious respiratory tract disease, are focused mainly on prophylactic vaccinations in conjunction with antiviral medications. Currently, several mammalian cell culture-based influenza vaccine production processes are being established, such as the technologies introduced by Novartis Behring (Optaflu®) or Baxter International Inc. (Celvapan). Downstream processing of influenza virus vaccines from cell culture supernatant can be performed by adsorbing virions onto sulfated column chromatography beads, such as Cellufine® sulfate. This study focused on the development of a sulfated cellulose membrane (SCM) chromatography unit operation to capture cell culture-derived influenza viruses. The advantages of the novel method were demonstrated for the Madin Darby canine kidney (MDCK) cell-derived influenza virus A/Puerto Rico/8/34 (H1N1). Furthermore, the SCM-Adsorbers were compared directly to column-based Cellufine® sulfate and commercially available cation-exchange membrane Adsorbers. Sulfated cellulose membrane Adsorbers showed high viral product recoveries. In addition, the SCM-capture step resulted in a higher reduction of dsDNA compared to the tested cation-exchange membrane Adsorbers. The productivity of the SCM-based unit operation could be significantly improved by a 30-fold increase in volumetric flow rate during adsorption compared to the bead-based capture method. The higher flow rate even further reduced the level of contaminating dsDNA by about twofold. The reproducibility and general applicability of the developed unit operation were demonstrated for two further MDCK cell-derived influenza virus strains: A/Wisconsin/67/2005 (H3N2) and B/Malaysia/2506/2004. Overall, SCM-Adsorbers represent a powerful and economically favorable alternative for influenza virus capture over conventional methods using Cellufine® sulfate. Biotechnol. Bioeng. 2009;103: 1144–1154. © 2009 Wiley Periodicals, Inc.
Yinhua Wan - One of the best experts on this subject based on the ideXlab platform.
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alginate dialdehyde meets nylon membrane a versatile platform for facile and green fabrication of membrane Adsorbers
Journal of Materials Chemistry, 2018Co-Authors: Kamran M Khan, Jianquan Luo, Xiangrong Chen, Zhaoshuai Wang, Rashid Khan, Yinhua WanAbstract:Alginate dialdehyde (ADA), a biocompatible polymer, was used as an intermediate layer on a nylon membrane to readily fabricate cation exchange (CEX), metal-affinity (Me-affinity), histidine-affinity (His-affinity) and peptide-affinity (Pep-affinity) membrane Adsorbers without any organic solvent usage. All the membrane Adsorbers exhibited a high selectivity in the fractionation of a IgG (immunoglobulin)/HSA (human serum albumin) mixture. Along with a high purity of 100%, a high IgG binding capacity of 30, 24, 21 and 28 mg mL⁻¹ (membrane volume) was achieved by the CEX, Me-affinity, His-affinity and Pep-affinity membrane Adsorbers in flow-through mode respectively, which is superior to those of the reported membrane Adsorbers. Furthermore, the CEX and Pep-affinity Adsorbers were tested for the separation of IgG from human plasma solution. The carboxylic groups along with the peptides on the Pep-affinity adsorber captured IgG synergistically with a higher recovery and purity (99% and 98.6%). This synergetic adsorber showed a qₘₐₓ and dynamic binding capacity (DBC) of 138.4 and 38.7 mg mL⁻¹ respectively for IgG binding which was somewhat higher than that of the reported protein A agarose (having qₘₐₓ and DBC of 84 and 24.4 mg g⁻¹ respectively). The present work indicated that the ADA layer not only activated the membrane surface to attach various adsorptive ligands under mild conditions, but also reduced non-specific adsorption. Due to the versatile linking function and green reaction conditions, the ADA coating on the nylon membrane is promising for the preparation of diverse membrane Adsorbers.
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facile and green fabrication of cation exchange membrane adsorber with unprecedented adsorption capacity for protein purification
Journal of Chromatography A, 2017Co-Authors: Kamran M Khan, Jinxin Fan, Jianquan Luo, Rashid Khan, Yinhua WanAbstract:Abstract Fabricating membrane Adsorbers with high adsorption capacity and appreciable throughput for the separation and purification of protein products is challenging in biomedical and pharmaceutical industries. Herein, we report the synthesis of a novel membrane adsorber by functionalizing a nylon microfiltration membrane with alginate dialdehyde (ADA) followed by sulphonic addition, without any solvent usage, and its successful application in the purification of lysozyme. Taking advantage of abundant dual cation exchange (CEX) groups on sulphonic-ADA (S-ADA) ligands, this novel S-ADA-nylon membrane adsorber showed an unprecedented static binding capicity of 286 mg/mL for lysozyme adsorption. Meanwhile, the prepared membrane adsorber could be easily regenerated (complete protein elution) under mild conditions and be reused at least for five times. Featured with a unique selectivity, the S-ADA-nylon membrane also captured lysozyme from chicken egg white solution with a high purity (100%) and a high recovery of 98%. The purified lysozyme showed similar specific activity as commercial product. The present work provides a facile, green and low-cost approach for the preparation of high-performance membrane Adsorbers, which has a great potential in protein production.
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polydopamine meets porous membrane a versatile platform for facile preparation of membrane Adsorbers
Journal of Chromatography A, 2016Co-Authors: Jinxin Fan, Jianquan Luo, Xiangrong Chen, Yinhua WanAbstract:Polydopamine, as an intermediate layer coated on PES membrane, was applied to fabricate various membrane Adsorbers. Anion-exchange, hydrophobic interaction and affinity membrane Adsorbers prepared by this facile method exhibited a high selectivity in fractionation of IgG (immunoglobulin)/HSA (human serum albumin) mixture. The anion-exchange membrane adsorber containing polyethylenimine (PEI) improved the HSA purity from 17.7% to 96.7%; The hydrophobic interaction membrane adsorber with Dodecyl mercaptan (DDM) as ligand obtained an IgG purity of 94.6%; Histidine attached affinity membrane chromatography achieved nearly a 100% purity of IgG. The present work indicated that the polydopamine layer not only activated membrane surface to attach various adsorptive ligands under the mild condition, but also reduced non-specific adsorption. Due to the versatile conjunction function, this facile mussel-inspired coating is also promising for the preparation of diverse membrane Adsorbers.
Ranil S Wickramasinghe - One of the best experts on this subject based on the ideXlab platform.
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anion exchange membrane Adsorbers for flow through polishing steps part ii virus host cell protein dna clearance and antibody recovery
Biotechnology and Bioengineering, 2013Co-Authors: Justin Weaver, Scott M Husson, Louise Murphy, Ranil S WickramasingheAbstract:Anion exchange membrane Adsorbers are used for contaminant removal in flow-through polishing steps in the manufacture of biopharmaceuticals. This contribution describes the clearance of minute virus of mice, DNA, and host cell proteins by three commercially available anion-exchange membranes: Sartobind Q, Mustang Q, and ChromaSorb. The Sartobind Q and Mustang Q products contain quaternary amine ligands; whereas, ChromaSorb contains primary amine based ligands. Performance was evaluated over a range of solution conditions: 0–200 mM NaCl, pH 6.0–9.0, and flow rates of 4–20 membrane volumes/min in the presence and absence of up to 50 mM phosphate and acetate. In addition contaminant clearance was determined in the presence and absence of 5 g/L monoclonal antibody. The quaternary amine based ligands depend mainly on Coulombic interactions for removal of negatively charged contaminants. Consequently, performance of Sartobind Q and Mustang Q was compromised at high ionic strength. Primary amine based ligands in ChromaSorb enable high capacities at high ionic strength due to the presence of secondary, hydrogen bonding interactions. However, the presence of hydrogen phosphate ions leads to reduced capacity. Monoclonal antibody recovery using primary amine based anion-exchange ligands may be lower if significant binding occurs due to secondary interactions. The removal of a specific contaminant is affected by the level of removal of the other contaminants. The results of this study may be used to help guide selection of commercially available membrane absorbers for flow-through polishing steps. Biotechnol. Bioeng. 2013; 110: 500–510. © 2012 Wiley Periodicals, Inc.
Anders Karlsson - One of the best experts on this subject based on the ideXlab platform.
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multilayered wideband absorbers for oblique angle of incidence
IEEE Transactions on Antennas and Propagation, 2010Co-Authors: Alireza Kazemzadeh, Anders KarlssonAbstract:Design procedures of Jaumann and circuit analog absorbers are mostly formulated for normal angle of incidence. Only a few design methods considering oblique angle of incidence are published. The published methods are restricted to single resistive layer circuit analog absorbers or multilayered Jaumann absorbers with low permittivity spacers. General design procedures are developed in this paper for multilayered Jaumann and capacitive circuit absorbers. By expanding the scan and frequency compensation techniques to multilayered structures, Jaumann absorbers with outstanding performances are designed. A capacitive circuit absorber is presented with a stable frequency response up to 45 for both polarizations, having an ultrawide bandwidth of 26 GHz.
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multilayered wideband absorbers for oblique angle of incidence
Technical Report LUTEDX (TEAT-7188) 1-18 (2010); TEAT-7188 (2010), 2010Co-Authors: Alireza Kazemzadeh, Anders KarlssonAbstract:Design procedures of Jaumann and circuit analog absorbers are mostly formulated for normal angle of incidence. Only a few design methods considering oblique angle of incidence are published. The published methods are restricted to single resistive layer circuit analog absorbers or multilayered Jaumann absorbers with low permittivity spacers. General design procedures are developed in this paper for multilayered Jaumann and capacitive circuit absorbers. By expanding the scan and frequency compensation techniques to multilayered structures, Jaumann absorbers with outstanding performances are designed. A capacitive circuit absorber is presented with a stable frequency response up to 45 Degrees for both polarizations, having an ultra wide bandwidth of 26 GHz. (Less)