Aditi Kaveti ’23
The field of medicine was revolutionized by the discovery of induced pluripotent stem cell (iPSC) techniques and the remarkable ability of these cells to solve various limitations in cell culture, including cellular proliferation and potency. Bioengineers are working to take advantage of the ability of these cells to improve cellular manufacturing and mechanization efficiency. A recent field of interest has been the effects of mechanical vibration, which is transmitted through cell culture vessels to the cultured iPSCs. Dr. Molly Frame, a professor in the Department of Biomedical Engineering at Stony Brook University, conducted a study to identify the physical mechanisms by which cells can sense applied mechanical vibrations.
Dr. Frame and her team began with determining the cellular mechanical environment. They quantified the fluid shear stresses induced by vibration that cells face in vitro. The two mechanical parameters that were tested were fluid shear and peak accelerations in response to the vibration. The team used the results of the cellular response to determine the relationship between the two parameters. They found that fluid shear was positively correlated to the magnitude of peak acceleration and that it was inversely related to vibration frequency. The team sought to use these in vivo experiments to separate the mechanisms and determine the way the signal is sensed and transduced by the cells.
The results of the experiments allowed Dr. Frame and her team to characterize the mechanical environment of cells in vitro during vibrations that exposed cells to both oscillatory accelerations and oscillatory fluid shear stress. The team went even further to perform applications of the vibrational system on an osteoblast-like cell line. The cell line was subjected to four different frequencies under two-fluid viscosities. The data highlighted shear stress as a predictor of the molecular response that may have played a role in influencing gene expression levels. The team will continue investigating other mechanical factors, such as out-of-phase acceleration of the cell nucleus, to further understand the transduction system in cells.
- Uzer, G., et al. Separating fluid shear stress from acceleration during vibrations in vitro: identification of mechanical signals modulating the cellular response. Cel. Mol. Bioeng. 5, 266–276 (2012). https://doi.org/10.1007/s12195-012-0231-1