The protective effect of specific medium additives with respect to bubble rupture

Abstract

A significant degree of cell damage is observed during suspension cell culture with air sparging. Protective agents can be added to the culture medium to protect the cells from damage. It has been observed that cells tend to adhere to air-medium interfaces and cell damage is mainly due to this cell-bubble interaction; protective additives have been found to prevent this cell adhesion to the bubble surfaces. In this article, it is demonstrated that the interfacial tension between the air and medium is related to the effectiveness of the protective additives to prevent adhesion of cells to this interface. Five different types of additives (Pluronic F-68, Methocels, dextran, Polyvinyl alcohol, and polyethylene glycols) were studied in an effort to determine their protective characteristics. Liquid-vapor interfacial tensions of the culture medium, with and without the additives, were measured by two different techniques (maximum bubble pressure method and Wilhelmy plate method). In addition, visualization techniques showed that in the presence of certain protective additives cells do not adhere to the bubble surface. Results obtained from these experiments indicate that the additives which rapidly lower the liquid-vapor interfacial tension of the culture medium also prevent adhesion of cells to the bubble surface. Experiments have also been conducted to determine the number of cells killed due to bubble rupture, and it was observed that this number is related to the amount of cells adhering to the bubble surface.

Production of Adenoviral Vectors in 293 Cells: A Case Study of the Adaptation of Attached Cells to Grow in Suspension

“…According to the results obtained, the agitation played an important role during the culture of suspension adapted 293 cells having a negative effect upon cell density and viability. The addition of a surfactant could help to overcome this problem, which has been reported previously for different mammalian cells [31][32][33][34][35].…”

The components of shear stress affecting insect cells used with the baculovirus expression vector system

“…The inclusion of 1 g·L −1 Pluronic prevents this and therefore limits the resulting damage [42]. The efficiency of protection strongly depends on the bubble size, the concentration of Pluronic, and the cell density [43].…”

Adaptation of the Se301 insect cell line to suspension culture. Effect of turbulence on growth and on production of nucleopolyhedrovius (SeMNPV)

“…Satisfactory results in the adaptation to suspension culture have been reported for several insect cell lines (e.g. T. ni or S. frugiperda) in which different additives were employed, such as serum, Pluronic F68 (PF68), methylcellulose, polyvinyl alcohol (PVA), polyethylene glycol (PEG), polyvinyl pyrrolidone (PVP), and dextrans (Van Lier et al 1996;Wu et al 1990;Papoutsakis 1991b;Palomares et al 2000;Chattopadhyay et al 1995;Dee et al 1997a, b).…”

“…To mitigate the harmful effects of certain shear stress levels on insect cells, different additives with protective effects have been proposed (Chattopadhyay et al 1995;Chisti 2000). The protection mechanisms and their effect depend greatly on the additive properties, the amount added and the cell line.…”