Cells and bubbles in sparged bioreactors.

Ever since animal cells have been grown in-vitro, various techniques have been used to supply the cells with oxygen. The most simple and commonly used 'large-scale' technique to provide oxygen is through the introduction of gas bubbles. However, almost since the beginning of in-vitro cell culture, empirical observations have indicated that bubbles can be detrimental to the cells. This review will discuss the background of the problem, review the relevant research on the topic, attempt to provide a coherent summary of what we know from all of this research, and finally outline what still needs to be investigated. Specific topics to be covered include: experimental correlations of cell damage with bubbles, cell attachment to bubbles, the hydrodynamics of bubble rupture, bioreactor studies, visualization studies, and computer simulations and qualification of cell death as a result of bubble rupture.