Acoustic Cell Processing for Viral Transduction or Bioreactor Cell Retention
A major limitation of retrovirus gene therapy technology is the often low percentage of target cells transduced. This is in part due to the low diffusivity of retroviruses, as well as their short half-life (~5 h). An approach to overcome these limitations has been developed using the forces in an acoustic standing wave field. An air-backflush mode of operation obtained up to 8-fold increases in TF-1 cell transduction compared to static controls and this was sustained from 2 to 24 h. The transduction increased as a function of power input, but at elevated power levels the acoustic transducer generated excessive heat. A new design with improved heat dissipation allowed continuous acoustic treatment over 2 days with no decrease in cell viability. This acoustically increased transduction reduces the need for additives and avoids the complications of recovering anchored cells. While acoustic separators can be used for bioreactor volumes ranging from hundreds of mL to >100 L, it is also important to define operational settings that avoid negative thermal influences on the cells. Additional cell culture experiments with CHO cells were performed to determine the acceptable temperature variations.
KeywordsChinese Hamster Ovary Cell Green Fluorescent Protein Expression Protamine Sulfate Spinner Flask Acoustic Transducer
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- Hennemann, B., E. Conneally, R. Pawliuk, P. Leboulch, S. Rose-John, D. Reid, J. Y. Chuo, R. K. Humphries and C. J. Eaves 1999. “Optimization of retroviral-mediated gene transfer to human NOD/SCID mouse repopulating cord blood cells through a systematic analysis of protocol variables.” Exp Hematol 27(5): 817–25.CrossRefGoogle Scholar
- Kuhlcke, K., B. Fehse, A. Schilz, S. Loges, C. Lindemann, F. Ayuk, F. Lehmann, N. Stute, A. A. Fauser, A. R. Zander and H. G. Eckert 2002. “Highly efficient retroviral gene transfer based on centrifugation-mediated vector preloading of tissue culture vessels.” Mol Ther 5(4): 473–8.CrossRefGoogle Scholar