The Experts below are selected from a list of 19851 Experts worldwide ranked by ideXlab platform

Udo Reichl - One of the best experts on this subject based on the ideXlab platform.

  • wave microcarrier cultivation of mdck Cells for influenza virus production in serum containing and serum free media
    Vaccine, 2006
    Co-Authors: Yvonne Genzel, Udo Reichl, R M Olmer, B Schafer
    Abstract:

    A process for equine influenza virus vaccine production using a microcarrier system (Cytodex 1) in a 2 L Wave bioreactor is described. Growth of Madin Darby canine kidney (MDCK) Cells in serum containing GMEM medium (SC) is compared to growth in serum-free Ex-Cell MDCK medium (SF) without washing steps and medium exchange before infection. Cultivations with microcarrier concentrations of 2 and 4 g/L for both media are shown. Metabolic data from carbon and amino acid metabolism are discussed. Additionally, in roller bottle experiments the influence of multiplicity of infection (moi) and trypsin concentration on the HA value was investigated. Analysis of HA and TCID(50) at 37 degrees C showed a stable HA of maximum 2.6 log HA/100 microL for 2 weeks. Peak TCID(50) titers of 10(7.7) viruses/mL were achieved 20h post infection, but infectivity was below detection limit after 150 h. Cell attachment onto microcarriers under serum-free conditions was improved by Ca(2+) addition and by Cell Harvesting without trypsin using only an EDTA/PBS solution. For the wave cultivation maximum virus titers of 2.3-2.6 log HA units/100 microL were reached from infection with a moi of 0.05. However, in SF medium pH dropped to less than pH 6.8 which resulted in lower HA titers of 1.7 log HA units/100 microL. For the higher microcarrier concentration (4 g/L) medium exchange steps (500 mL) were needed for both media. Omission of the washing step and medium exchange before infection in SF medium clearly simplified the influenza production process; however, for higher virus yields a better pH control of the wave bioreactor would be required. Higher Cell densities (2.8 x 10(6) Cells/mL for 2 g/L microcarrier) and better attachment compared to stirred tank bioreactors showed, that the wave bioreactor is a good alternative to stirred tank processes for expanding production capacities in case of a pandemic.

  • wave microcarrier cultivation of mdck Cells for influenza virus production in serum containing and serum free media
    Vaccine, 2006
    Co-Authors: Yvonne Genzel, Udo Reichl, R M Olmer, B Schafer
    Abstract:

    Abstract A process for equine influenza virus vaccine production using a microcarrier system (Cytodex 1) in a 2 L Wave bioreactor is described. Growth of Madin Darby canine kidney (MDCK) Cells in serum containing GMEM medium (SC) is compared to growth in serum-free Ex-Cell MDCK medium (SF) without washing steps and medium exchange before infection. Cultivations with microcarrier concentrations of 2 and 4 g/L for both media are shown. Metabolic data from carbon and amino acid metabolism are discussed. Additionally, in roller bottle experiments the influence of multiplicity of infection (moi) and trypsin concentration on the HA value was investigated. Analysis of HA and TCID 50 at 37 °C showed a stable HA of maximum 2.6 log HA/100 μL for 2 weeks. Peak TCID 50 titers of 10 7.7 viruses/mL were achieved 20 h post infection, but infectivity was below detection limit after 150 h. Cell attachment onto microcarriers under serum-free conditions was improved by Ca 2+ addition and by Cell Harvesting without trypsin using only an EDTA/PBS solution. For the wave cultivation maximum virus titers of 2.3–2.6 log HA units/100 μL were reached from infection with a moi of 0.05. However, in SF medium pH dropped to less than pH 6.8 which resulted in lower HA titers of 1.7 log HA units/100 μL. For the higher microcarrier concentration (4 g/L) medium exchange steps (500 mL) were needed for both media. Omission of the washing step and medium exchange before infection in SF medium clearly simplified the influenza production process; however, for higher virus yields a better pH control of the wave bioreactor would be required. Higher Cell densities (2.8 × 10 6  Cells/mL for 2 g/L microcarrier) and better attachment compared to stirred tank bioreactors showed, that the wave bioreactor is a good alternative to stirred tank processes for expanding production capacities in case of a pandemic.

Christopher J Hewitt - One of the best experts on this subject based on the ideXlab platform.

  • expansion of human mesenchymal stem stromal Cells on temporary liquid microcarriers
    Journal of Chemical Technology & Biotechnology, 2021
    Co-Authors: Christopher J Hewitt, Mariana Hanga, Alvin Nienow, Halina Murasiewicz, Andrzej Pacek
    Abstract:

    Background Traditional large-scale culture systems for human mesenchymal stem/stromal Cells (hMSCs) use solid microcarriers as attachment substrates. Although the use of such substrates is advantageous because of the high surface-to-volume ratio, Cell harvest from the same substrates is a challenge as it requires enzymatic treatment, often combined with agitation. Here, we investigated a two-phase system for expansion and non-enzymatic recovery of hMSCs. Perfluorocarbon droplets were dispersed in a protein-rich growth medium and were used as temporary liquid microcarriers for hMSC culture. Results hMSCs successfully attached to these liquid microcarriers, exhibiting similar morphologies to those cultured on solid ones. Fold increases of 3.03 ± 0.98 (hMSC1) and 3.81 ± 0.29 (hMSC2) were achieved on day 9. However, the maximum expansion folds were recorded on day 4 (4.79 ± 0.47 (hMSC1) and 4.856 ± 0.7 (hMSC2)). This decrease was caused by Cell aggregation upon reaching confluency due to the contraction of the interface between the two phases. Cell quality, as assessed by differentiation, Cell surface marker expression and clonogenic ability, was retained post expansion on the liquid microcarriers. Cell Harvesting was achieved non-enzymatically in two steps: first by inducing droplet coalescence and then aspirating the interface. Quality characteristics of hMSCs continued to be retained even after inducing droplet coalescence. Conclusion The prospect of a temporary microcarrier that can be used to expand Cells and then 'disappear' for Cell release without using proteolytic enzymes is a very exciting one. Here, we have demonstrated that hMSCs can attach and proliferate on these perfluorocarbon liquid microcarriers while, very importantly, retaining their quality.

Mariana Hanga - One of the best experts on this subject based on the ideXlab platform.

  • expansion of human mesenchymal stem stromal Cells on temporary liquid microcarriers
    Journal of Chemical Technology & Biotechnology, 2021
    Co-Authors: Christopher J Hewitt, Mariana Hanga, Alvin Nienow, Halina Murasiewicz, Andrzej Pacek
    Abstract:

    Background Traditional large-scale culture systems for human mesenchymal stem/stromal Cells (hMSCs) use solid microcarriers as attachment substrates. Although the use of such substrates is advantageous because of the high surface-to-volume ratio, Cell harvest from the same substrates is a challenge as it requires enzymatic treatment, often combined with agitation. Here, we investigated a two-phase system for expansion and non-enzymatic recovery of hMSCs. Perfluorocarbon droplets were dispersed in a protein-rich growth medium and were used as temporary liquid microcarriers for hMSC culture. Results hMSCs successfully attached to these liquid microcarriers, exhibiting similar morphologies to those cultured on solid ones. Fold increases of 3.03 ± 0.98 (hMSC1) and 3.81 ± 0.29 (hMSC2) were achieved on day 9. However, the maximum expansion folds were recorded on day 4 (4.79 ± 0.47 (hMSC1) and 4.856 ± 0.7 (hMSC2)). This decrease was caused by Cell aggregation upon reaching confluency due to the contraction of the interface between the two phases. Cell quality, as assessed by differentiation, Cell surface marker expression and clonogenic ability, was retained post expansion on the liquid microcarriers. Cell Harvesting was achieved non-enzymatically in two steps: first by inducing droplet coalescence and then aspirating the interface. Quality characteristics of hMSCs continued to be retained even after inducing droplet coalescence. Conclusion The prospect of a temporary microcarrier that can be used to expand Cells and then 'disappear' for Cell release without using proteolytic enzymes is a very exciting one. Here, we have demonstrated that hMSCs can attach and proliferate on these perfluorocarbon liquid microcarriers while, very importantly, retaining their quality.

  • Expansion of human mesenchymal stem/stromal Cells on temporary liquid microcarriers
    2020
    Co-Authors: Mariana Hanga, Alvin Nienow, Halina Murasiewicz, Andrzej Pacek, Chris Hewitt, Karen Coopman
    Abstract:

    Background: Traditional large scale culture systems for human mesenchymal stem/stromal Cells (hMSCs) use solid microcarriers as attachment substrates. While the use of such substrates is advantageous due to the high surface-to-volume ratio, Cell harvest from the same substrates is a challenge as it requires enzymatic treatment, often combined with agitation. Here, we investigated a two-phase system for expansion and non-enzymatic recovery of hMSCs. Perfluorocarbon droplets were dispersed in a protein-rich growth medium and were used as temporary liquid microcarriers for hMSC culture. Results: hMSCs successfully attached to these liquid microcarriers exhibiting similar morphologies to those cultured on solid ones. Fold increases of 3.03±0.98 (hMSC1) and 3.81±0.29 (hMSC2) were achieved at day 9. However, the maximum expansion folds were recorded at day 4 (4.79±0.47 (hMSC1) and 4.856±0.7 (hMSC2)). This decrease was caused by Cell aggregation upon reaching confluency due to the contraction of the interface between the two phases. Cell quality as assessed by differentiation, Cell surface marker expression and clonogenic ability was retained post-expansion on the liquid microcarriers. Cell Harvesting was achieved non-enzymatically in two steps, by firstly inducing droplet coalescence, then aspirating the interface. hMSCs’ quality characteristics continued to be retained even after inducing droplet coalescence.Conclusion: The prospect of a temporary microcarrier that can be used to expand Cells and then ‘disappear’ for Cell release without using proteolytic enzymes is a very exciting one. Here, we’ve demonstrated that hMSCs can attach and proliferate on these perfluorocarbon liquid microcarriers, while very importantly retaining their quality.

  • Expansion of human mesenchymal stem/stromal Cells (hMSCs) on temporary liquid microcarriers
    2020
    Co-Authors: Mariana Hanga, Alvin Nienow, Halina Murasiewicz, Andrzej Pacek, Chris Hewitt, Karen Coopman
    Abstract:

    Background: Traditional large scale culture systems for human mesenchymal stem/stromal Cells (hMSCs) use solid microcarriers as attachment substrates. While the use of such substrates is advantageous due to the high surface-to-volume ratio, Cell harvest from the same substrates is a challenge as it requires enzymatic treatment, often combined with agitation. Here, we investigated a two-phase system for expansion and non-enzymatic recovery of hMSCs. Perfluorocarbon droplets were dispersed in a protein-rich growth medium and were used as temporary liquid microcarriers for hMSC culture. Results: hMSCs successfully attached to these liquid microcarriers exhibiting similar morphologies to those cultured on solid ones. Fold increases of 3.03±0.98 (hMSC1) and 3.81±0.29 (hMSC2) were achieved at day 9. However, the maximum expansion folds were recorded at day 4 (4.79±0.47 (hMSC1) and 4.856±0.7 (hMSC2)). This decrease was caused by Cell aggregation upon reaching confluency due to the contraction of the interface between the two phases. Cell quality as assessed by differentiation, Cell surface marker expression and clonogenic ability was retained post-expansion on the liquid microcarriers. Cell Harvesting was achieved non-enzymatically in two steps, by firstly inducing droplet coalescence, then aspirating the interface. hMSCs’ quality characteristics continued to be retained even after inducing droplet coalescence.Conclusion: The prospect of a temporary microcarrier that can be used to expand Cells and then ‘disappear’ for Cell release without using proteolytic enzymes is a very exciting one. Here, we’ve demonstrated that hMSCs can attach and proliferate on these perfluorocarbon liquid microcarriers, while very importantly retaining their quality.

Alvin Nienow - One of the best experts on this subject based on the ideXlab platform.

  • expansion of human mesenchymal stem stromal Cells on temporary liquid microcarriers
    Journal of Chemical Technology & Biotechnology, 2021
    Co-Authors: Christopher J Hewitt, Mariana Hanga, Alvin Nienow, Halina Murasiewicz, Andrzej Pacek
    Abstract:

    Background Traditional large-scale culture systems for human mesenchymal stem/stromal Cells (hMSCs) use solid microcarriers as attachment substrates. Although the use of such substrates is advantageous because of the high surface-to-volume ratio, Cell harvest from the same substrates is a challenge as it requires enzymatic treatment, often combined with agitation. Here, we investigated a two-phase system for expansion and non-enzymatic recovery of hMSCs. Perfluorocarbon droplets were dispersed in a protein-rich growth medium and were used as temporary liquid microcarriers for hMSC culture. Results hMSCs successfully attached to these liquid microcarriers, exhibiting similar morphologies to those cultured on solid ones. Fold increases of 3.03 ± 0.98 (hMSC1) and 3.81 ± 0.29 (hMSC2) were achieved on day 9. However, the maximum expansion folds were recorded on day 4 (4.79 ± 0.47 (hMSC1) and 4.856 ± 0.7 (hMSC2)). This decrease was caused by Cell aggregation upon reaching confluency due to the contraction of the interface between the two phases. Cell quality, as assessed by differentiation, Cell surface marker expression and clonogenic ability, was retained post expansion on the liquid microcarriers. Cell Harvesting was achieved non-enzymatically in two steps: first by inducing droplet coalescence and then aspirating the interface. Quality characteristics of hMSCs continued to be retained even after inducing droplet coalescence. Conclusion The prospect of a temporary microcarrier that can be used to expand Cells and then 'disappear' for Cell release without using proteolytic enzymes is a very exciting one. Here, we have demonstrated that hMSCs can attach and proliferate on these perfluorocarbon liquid microcarriers while, very importantly, retaining their quality.

  • Expansion of human mesenchymal stem/stromal Cells on temporary liquid microcarriers
    2020
    Co-Authors: Mariana Hanga, Alvin Nienow, Halina Murasiewicz, Andrzej Pacek, Chris Hewitt, Karen Coopman
    Abstract:

    Background: Traditional large scale culture systems for human mesenchymal stem/stromal Cells (hMSCs) use solid microcarriers as attachment substrates. While the use of such substrates is advantageous due to the high surface-to-volume ratio, Cell harvest from the same substrates is a challenge as it requires enzymatic treatment, often combined with agitation. Here, we investigated a two-phase system for expansion and non-enzymatic recovery of hMSCs. Perfluorocarbon droplets were dispersed in a protein-rich growth medium and were used as temporary liquid microcarriers for hMSC culture. Results: hMSCs successfully attached to these liquid microcarriers exhibiting similar morphologies to those cultured on solid ones. Fold increases of 3.03±0.98 (hMSC1) and 3.81±0.29 (hMSC2) were achieved at day 9. However, the maximum expansion folds were recorded at day 4 (4.79±0.47 (hMSC1) and 4.856±0.7 (hMSC2)). This decrease was caused by Cell aggregation upon reaching confluency due to the contraction of the interface between the two phases. Cell quality as assessed by differentiation, Cell surface marker expression and clonogenic ability was retained post-expansion on the liquid microcarriers. Cell Harvesting was achieved non-enzymatically in two steps, by firstly inducing droplet coalescence, then aspirating the interface. hMSCs’ quality characteristics continued to be retained even after inducing droplet coalescence.Conclusion: The prospect of a temporary microcarrier that can be used to expand Cells and then ‘disappear’ for Cell release without using proteolytic enzymes is a very exciting one. Here, we’ve demonstrated that hMSCs can attach and proliferate on these perfluorocarbon liquid microcarriers, while very importantly retaining their quality.

  • Expansion of human mesenchymal stem/stromal Cells (hMSCs) on temporary liquid microcarriers
    2020
    Co-Authors: Mariana Hanga, Alvin Nienow, Halina Murasiewicz, Andrzej Pacek, Chris Hewitt, Karen Coopman
    Abstract:

    Background: Traditional large scale culture systems for human mesenchymal stem/stromal Cells (hMSCs) use solid microcarriers as attachment substrates. While the use of such substrates is advantageous due to the high surface-to-volume ratio, Cell harvest from the same substrates is a challenge as it requires enzymatic treatment, often combined with agitation. Here, we investigated a two-phase system for expansion and non-enzymatic recovery of hMSCs. Perfluorocarbon droplets were dispersed in a protein-rich growth medium and were used as temporary liquid microcarriers for hMSC culture. Results: hMSCs successfully attached to these liquid microcarriers exhibiting similar morphologies to those cultured on solid ones. Fold increases of 3.03±0.98 (hMSC1) and 3.81±0.29 (hMSC2) were achieved at day 9. However, the maximum expansion folds were recorded at day 4 (4.79±0.47 (hMSC1) and 4.856±0.7 (hMSC2)). This decrease was caused by Cell aggregation upon reaching confluency due to the contraction of the interface between the two phases. Cell quality as assessed by differentiation, Cell surface marker expression and clonogenic ability was retained post-expansion on the liquid microcarriers. Cell Harvesting was achieved non-enzymatically in two steps, by firstly inducing droplet coalescence, then aspirating the interface. hMSCs’ quality characteristics continued to be retained even after inducing droplet coalescence.Conclusion: The prospect of a temporary microcarrier that can be used to expand Cells and then ‘disappear’ for Cell release without using proteolytic enzymes is a very exciting one. Here, we’ve demonstrated that hMSCs can attach and proliferate on these perfluorocarbon liquid microcarriers, while very importantly retaining their quality.

Halina Murasiewicz - One of the best experts on this subject based on the ideXlab platform.

  • expansion of human mesenchymal stem stromal Cells on temporary liquid microcarriers
    Journal of Chemical Technology & Biotechnology, 2021
    Co-Authors: Christopher J Hewitt, Mariana Hanga, Alvin Nienow, Halina Murasiewicz, Andrzej Pacek
    Abstract:

    Background Traditional large-scale culture systems for human mesenchymal stem/stromal Cells (hMSCs) use solid microcarriers as attachment substrates. Although the use of such substrates is advantageous because of the high surface-to-volume ratio, Cell harvest from the same substrates is a challenge as it requires enzymatic treatment, often combined with agitation. Here, we investigated a two-phase system for expansion and non-enzymatic recovery of hMSCs. Perfluorocarbon droplets were dispersed in a protein-rich growth medium and were used as temporary liquid microcarriers for hMSC culture. Results hMSCs successfully attached to these liquid microcarriers, exhibiting similar morphologies to those cultured on solid ones. Fold increases of 3.03 ± 0.98 (hMSC1) and 3.81 ± 0.29 (hMSC2) were achieved on day 9. However, the maximum expansion folds were recorded on day 4 (4.79 ± 0.47 (hMSC1) and 4.856 ± 0.7 (hMSC2)). This decrease was caused by Cell aggregation upon reaching confluency due to the contraction of the interface between the two phases. Cell quality, as assessed by differentiation, Cell surface marker expression and clonogenic ability, was retained post expansion on the liquid microcarriers. Cell Harvesting was achieved non-enzymatically in two steps: first by inducing droplet coalescence and then aspirating the interface. Quality characteristics of hMSCs continued to be retained even after inducing droplet coalescence. Conclusion The prospect of a temporary microcarrier that can be used to expand Cells and then 'disappear' for Cell release without using proteolytic enzymes is a very exciting one. Here, we have demonstrated that hMSCs can attach and proliferate on these perfluorocarbon liquid microcarriers while, very importantly, retaining their quality.

  • Expansion of human mesenchymal stem/stromal Cells on temporary liquid microcarriers
    2020
    Co-Authors: Mariana Hanga, Alvin Nienow, Halina Murasiewicz, Andrzej Pacek, Chris Hewitt, Karen Coopman
    Abstract:

    Background: Traditional large scale culture systems for human mesenchymal stem/stromal Cells (hMSCs) use solid microcarriers as attachment substrates. While the use of such substrates is advantageous due to the high surface-to-volume ratio, Cell harvest from the same substrates is a challenge as it requires enzymatic treatment, often combined with agitation. Here, we investigated a two-phase system for expansion and non-enzymatic recovery of hMSCs. Perfluorocarbon droplets were dispersed in a protein-rich growth medium and were used as temporary liquid microcarriers for hMSC culture. Results: hMSCs successfully attached to these liquid microcarriers exhibiting similar morphologies to those cultured on solid ones. Fold increases of 3.03±0.98 (hMSC1) and 3.81±0.29 (hMSC2) were achieved at day 9. However, the maximum expansion folds were recorded at day 4 (4.79±0.47 (hMSC1) and 4.856±0.7 (hMSC2)). This decrease was caused by Cell aggregation upon reaching confluency due to the contraction of the interface between the two phases. Cell quality as assessed by differentiation, Cell surface marker expression and clonogenic ability was retained post-expansion on the liquid microcarriers. Cell Harvesting was achieved non-enzymatically in two steps, by firstly inducing droplet coalescence, then aspirating the interface. hMSCs’ quality characteristics continued to be retained even after inducing droplet coalescence.Conclusion: The prospect of a temporary microcarrier that can be used to expand Cells and then ‘disappear’ for Cell release without using proteolytic enzymes is a very exciting one. Here, we’ve demonstrated that hMSCs can attach and proliferate on these perfluorocarbon liquid microcarriers, while very importantly retaining their quality.

  • Expansion of human mesenchymal stem/stromal Cells (hMSCs) on temporary liquid microcarriers
    2020
    Co-Authors: Mariana Hanga, Alvin Nienow, Halina Murasiewicz, Andrzej Pacek, Chris Hewitt, Karen Coopman
    Abstract:

    Background: Traditional large scale culture systems for human mesenchymal stem/stromal Cells (hMSCs) use solid microcarriers as attachment substrates. While the use of such substrates is advantageous due to the high surface-to-volume ratio, Cell harvest from the same substrates is a challenge as it requires enzymatic treatment, often combined with agitation. Here, we investigated a two-phase system for expansion and non-enzymatic recovery of hMSCs. Perfluorocarbon droplets were dispersed in a protein-rich growth medium and were used as temporary liquid microcarriers for hMSC culture. Results: hMSCs successfully attached to these liquid microcarriers exhibiting similar morphologies to those cultured on solid ones. Fold increases of 3.03±0.98 (hMSC1) and 3.81±0.29 (hMSC2) were achieved at day 9. However, the maximum expansion folds were recorded at day 4 (4.79±0.47 (hMSC1) and 4.856±0.7 (hMSC2)). This decrease was caused by Cell aggregation upon reaching confluency due to the contraction of the interface between the two phases. Cell quality as assessed by differentiation, Cell surface marker expression and clonogenic ability was retained post-expansion on the liquid microcarriers. Cell Harvesting was achieved non-enzymatically in two steps, by firstly inducing droplet coalescence, then aspirating the interface. hMSCs’ quality characteristics continued to be retained even after inducing droplet coalescence.Conclusion: The prospect of a temporary microcarrier that can be used to expand Cells and then ‘disappear’ for Cell release without using proteolytic enzymes is a very exciting one. Here, we’ve demonstrated that hMSCs can attach and proliferate on these perfluorocarbon liquid microcarriers, while very importantly retaining their quality.