Influence of simulated microgravity on the longevity of insect-cell culture

Cowger, Nancy L.; O’Connor, Kim C.; Bivins, Jessica E.

doi:10.1016/s0141-0229(96)00153-6

Cited by 16 publications

(6 citation statements)

References 22 publications

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“…Two types of necrotic cell death, primary (resulting from passive damage) and secondary (occurring at the latest stage of apoptosis) have been inferred by Cowger et al (1997) in insect cells from the DNA smears obtained in agarose gel electrophoresis. Nonspecific DNA degradation was corroborated by the presence of a sub-G1 population rather than a sharply defined sub-G1 peak.…”

Section: Discussionmentioning

confidence: 99%

Comparative characterization of cell death between Sf9 insect cells and hybridoma cultures

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Merchant³

et al. 2001

Biotechnol. Bioeng.

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Physiological cell death (PCD) in Sf9 insect cell batch cultures was comprehensively characterized using simultaneous determinations of qualitative and quantitative assays, including agarose gel electrophoresis, confocal, epifluorescence, and transmission electron microscopy, and DNA content by flow cytometry. Results were compared to hybridoma cultures where abundant information of apoptosis exists. Both cultures shared some typical apoptosis features, including cell shrinkage, loss of sphericity, swollen endoplasmic reticulum and Golgi apparatus, chromatin condensation, and specific DNA degradation. However, distinctive morphological and kinetic differences between both cultures revealed that Sf9 cells died by an atypical PCD process characterized by absence of nuclear fragmentation, scarce association of condensed chromatin to the nuclear envelope, swollen mitochondria, and high nonspecific DNA degradation. These features, distinctive of necrosis, were not observed in the normal apoptotic process of hybridomas. Glucose depletion marked the appearance of apoptotic Sf9 cells, which there up on increased gradually, whereas apoptotic hybridomas rapidly increased upon glutamine depletion. Furthermore, active phagocytosis was found in Sf9 viable cells, a characteristic phenomenon during in vivo apoptosis but uncommon for in vitro cultures. Sf9 cells contained unusually high numbers of phagosomes, particularly after glucose depletion. Additionally, few apoptotic bodies accumulated in culture, suggesting their elimination by phagocytosis. Other distinctive characteristics of Sf9 cells were the presence of a polynucleated hypertrophic population fraction, polyploidy, cell cycle arrest in G2/M phase, and more necrosis compared to hybridomas. Such phenomena prevented a reliable quantification of apoptosis from determination of the sub‐G1 peak. Nonetheless, emergence of a bimodal Sf9 cell size distribution coincided with the increase in the sub‐G1 population and onset of death. The fraction of particles in the smaller peak (6–11 μm diameter) closely correlated with the fractions of apoptotic bodies, late apoptotic, and secondary necrotic cells. Accordingly, Sf9 cell size was shown to be an effective, rapid, and simple parameter for quantifying death. Altogether, the results of this study provide new insights into PCD and other phenomena in insect cell culture important for biotechnological applications of Sf9 cells. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 72: 441–457, 2001.

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Section: Discussionmentioning

confidence: 99%

Comparative characterization of cell death between Sf9 insect cells and hybridoma cultures

Meneses‐Acosta

Mendonça

Merchant³

et al. 2001

Biotechnol. Bioeng.

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show abstract

“…Agarose gel electrophoresis determinations of Sf9 cells presented a mixed pattern of DNA degradation, whereas for hybridomas a sharper DNA ladder pattern was obtained. Two types of necrotic cell death, primary (resulting from passive damage) and secondary (occurring at the latest stage of apoptosis) have been inferred by Cowger et al (1997) in insect cells from the DNA smears obtained in agarose gel electrophoresis. Nonspecific DNA degradation was corroborated by the presence of a sub-G1 population rather than a sharply defined sub-G1 peak.…”

Section: Discussionmentioning

confidence: 99%

Comparative characterization of cell death between Sf9 insect cells and hybridoma cultures

Meneses‐Acosta

Mendonça

Merchant³

et al. 2001

Biotechnol. Bioeng.

View full text Add to dashboard Cite

Physiological cell death (PCD) in Sf9 insect cell batch cultures was comprehensively characterized using simultaneous determinations of qualitative and quantitative assays, including agarose gel electrophoresis, confocal, epifluorescence, and transmission electron microscopy, and DNA content by flow cytometry. Results were compared to hybridoma cultures where abundant information of apoptosis exists. Both cultures shared some typical apoptosis features, including cell shrinkage, loss of sphericity, swollen endoplasmic reticulum and Golgi apparatus, chromatin condensation, and specific DNA degradation. However, distinctive morphological and kinetic differences between both cultures revealed that Sf9 cells died by an atypical PCD process characterized by absence of nuclear fragmentation, scarce association of condensed chromatin to the nuclear envelope, swollen mitochondria, and high nonspecific DNA degradation. These features, distinctive of necrosis, were not observed in the normal apoptotic process of hybridomas. Glucose depletion marked the appearance of apoptotic Sf9 cells, which there up on increased gradually, whereas apoptotic hybridomas rapidly increased upon glutamine depletion. Furthermore, active phagocytosis was found in Sf9 viable cells, a characteristic phenomenon during in vivo apoptosis but uncommon for in vitro cultures. Sf9 cells contained unusually high numbers of phagosomes, particularly after glucose depletion. Additionally, few apoptotic bodies accumulated in culture, suggesting their elimination by phagocytosis. Other distinctive characteristics of Sf9 cells were the presence of a polynucleated hypertrophic population fraction, polyploidy, cell cycle arrest in G2/M phase, and more necrosis compared to hybridomas. Such phenomena prevented a reliable quantification of apoptosis from determination of the sub-G1 peak. Nonetheless, emergence of a bimodal Sf9 cell size distribution coincided with the increase in the sub-G1 population and onset of death. The fraction of particles in the smaller peak (6-11 microm diameter) closely correlated with the fractions of apoptotic bodies, late apoptotic, and secondary necrotic cells. Accordingly, Sf9 cell size was shown to be an effective, rapid, and simple parameter for quantifying death. Altogether, the results of this study provide new insights into PCD and other phenomena in insect cell culture important for biotechnological applications of Sf9 cells.

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“…Similar trend was observed in the UV polymerization of thiol-ene by Chiou et al13 Conversion dependent shear modulus during curingThe modulus (G) developed during cure can be correlated to the shrinkage (Figure 4.10) since modulus can be related to the molecular weight between crosslinking (M c )…”

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confidence: 76%

“…High aspect ratio microstructures offer a high ratio of active surface area to substrate area leading to increased sensitivity and further miniaturization, higher active surface area and multilevel microstructures are important for chemical and biochemical applications such as microreactors, micromixers, chromatographic columns or DNA concentrators to allow large fluid flow volume for good analysis, performance and multitasking within a small area. High aspect ratio microstructures are also desirable for biological Micro Electro-Mechanical systems (bioMEMS) applications such as protein microarrays, drug and cell encapsulation, diagnostics, controlled drug release and tissue engineering [12][13][14] . High aspect ratio microstructure is important for studying the effect of three-dimensional topological constraints on the function of biologics such as proteins and cells 15-18 . In many applications, issues such as material compatibility, large area molding, substrate flexibility or residual stress have to be considered.…”

Section: High Aspect Ratio Embossingmentioning

confidence: 99%

Fundamental studies of large area and high aspect ratio UV embossing

Zhou¹

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Influence of simulated microgravity on the longevity of insect-cell culture

Cited by 16 publications

References 22 publications

Comparative characterization of cell death between Sf9 insect cells and hybridoma cultures

Comparative characterization of cell death between Sf9 insect cells and hybridoma cultures

Comparative characterization of cell death between Sf9 insect cells and hybridoma cultures

Fundamental studies of large area and high aspect ratio UV embossing

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