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Physical modeling of animal cell damage by hydrodynamic forces in suspension cultures
Author(s) -
Lu George Z.,
Gray Murray R.,
Thompson B. G.
Publication year - 1992
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260401018
Subject(s) - bioreactor , breakage , bubble , sparging , entrainment (biomusicology) , suspension (topology) , materials science , chromatography , chemistry , chemical engineering , composite material , mechanics , philosophy , physics , organic chemistry , homotopy , rhythm , pure mathematics , engineering , aesthetics , mathematics
Physical damage of animal cells in suspension culture, due to stirring and sparging, is coupled with complex metabolic responses. Nylon microcapsules, therefore, were used as a physical model to study the mechanisms of damage in a stirred bioreactor and in a bubble column. Microcapsule breaskage folowed first‐order kinetices in all experiments Entrainment of bubbles into the liquid phase in the stirred bioreactor gave more microcapsule breakage. In the bubble column, the bubble bursting zone at gas–liquid interface was primarilu responsible for microcapsule breakage. The forces on the microcapsules were equivalent to an external pressure of approximately 4 × 10 4 N · m −2 , based on the critical microcapsule diameter for survival of 190 μm. A stable foam layer, however, was found to be effective in protecting microcapsules from damage. The microcapsule transport to the gas–liquid interface and entrainment into the foam phase was consistent with flotation by air bubbles. This result implies that additives and operation of bioreactors should be selected to minimize flotation of cells. © 1992 John Wiley & Sons, Inc.