Pluronic Enhances the Robustness and Reduces the Cell Attachment of Mammalian Cells

Abstract

The addition of the non-ionic surfactant, Pluronic F-68, to serum-free CHO cultures causes multi-functional effects that enhance cell yield in agitated cultures and reduce cell adhesion in stationary cultures. Three independent CHO cell lines were subjected to high liquid shear in assay systems that either included or excluded a liquid-gas interface. In the absence of Pluronic, there was a loss in cell viability in either assay system, although there was an intrinsic variability in sensitivity of the cell lines to shear damage. Supplementation with Pluronic prevented loss of cell viability, indicating protection in either a gas sparged or bubble-free environment. However, we found no evidence of long-term protection of cells once Pluronic was removed. Pluronic was capable of repairing trypsin-damaged cells as evidenced by enhanced growth, reduced membrane porosity, and improved robustness under liquid shear. The proportion of adherent cells was reduced to a minimal level by the presence of Pluronic although its effect was rapidly reversible with a high proportion (70%) of adherent cells observed within a few culture passages of its removal. The observed effects of Pluronic on these cultures are compatible with a mechanism in which the polymer forms a protective layer on the cell membrane, which has a significantly lower hydrophobicity.

Celastrol enhances AAV1-mediated gene expression in mice adipose tissues

“…10 The exact mechanism was unclear. Pluronics were reported to enter the cells via clathrinmediated endocytosis 11 and form a protective lower hydrophobic layer on the cell membrane to enhance the robustness and reduce the cell attachment, 12 protect the cell membrane following electroporation, 13 increase the DNA intracellular diffusion 14 and the translocation of DNA into the nuclei. 15 Pluronics have been used as one of the clinical drug excipients, and promoted DNA into the nucleus and may potentially activate nuclear factor-kB.…”

Enhanced Production of Human Recombinant Proteins from CHO cells Grown to High Densities in Macroporous Microcarriers

“…CHO is the most widely used cell line for the production of recombinant proteins and the cells may be grown in suspension but can be induced to attach to a treated surface under appropriate culture conditions [1]. Although most bioprocesses for biopharmaceutical production have been designed for suspension cultures, there can be advantages of maintaining immobilized cells.…”

Scale-down of CHO cell fed-batch cultures

“…In addition, Pluronic F-68 may also decrease surface tension and thus decrease the energy generated from bubble bursting 228 . Increase in Pluronic F-68 up to 2 g/L generally showed increasing protection effect for CHO and insect cells against shear damage 225,227,229 .…”

“…the burst of smaller bubbles is more detrimental to cells. Currently, shear protective reagents such as the Pluronic F-68 have largely solved the problem related to the bubble damage [225][226][227] . Several possible protective mechanisms of Pluronic F-68 have been proposed.…”

“…Several possible protective mechanisms of Pluronic F-68 have been proposed. One is that it forms a protective layer on the cell membrane which increases the shear resistance of the cells 227 . Another explanation is that it saturates the air-liquid interface and therefore displacing cells 226 .…”