Electrical and mechanical manipulation of single cells

In this post-genomic era, we are well poised to investigate dynamic processes at the cellular systems level---and to leverage this to engineer therapeutically useful cells for molecular medicine. With the wealth of information garnered from genomics and proteomics, the pieces must now be assembled to better understand how the parts interact with each other in a cell---our smallest functional 'system'. Understanding the behavior of this system offers critical insight for predictive medicine. Leveraging the inherent scaling advantages of microsystems enables us to intricately examine and interrogate the cell.; We have developed such microsystems for the electrical and mechanical manipulation of whole cells. Specifically, the focus is on a single-cell electroporation array to introduce otherwise impermeable materials (e.g. DNA, RNA, proteins, drugs, and dyes) into cells. While few high-resolution methods exist to control and manipulate the biochemical nature of a single cell's interior1,2 , roughly 90% of the cell's biologically active structures, such as intracellular proteins, reside in this space, within the confines of the relatively impermeable cell membrane.; Therefore, such technology is imperative for gene therapy and drug discovery. By trapping individual cells and then applying an electric field across each cell, I have been able to demonstrate the well-controlled opening and closing of the cell membrane (a process called reversible electroporation) as well as the introduction of material into the cell. Real time optical and electrical measurements are used to monitor the electroporation process and to quantify the loading of the cells. This unique approach to electroporation also enables the investigation of previously unattainable membrane biophysical phenomena.; In addition to electroporating cells, I will present other designs leveraging the same principle, such as using electric fields for cell fusion. I will also present some strides I have made in chip interfacing and surface modification---necessary ingredients to develop a complete and reliable microsystem. My future research goals include integrating these various devices and applying them to meet real world biomedical challenges such as drug discovery and siRNA delivery.; 1 1. J.A. Lundqvist, F. Sahlin, M.A.I. Aberg, A. Stromberg, P.S. Eriksson, O. Orwar, Proc. Natl. Acad. Sci. U.S.A. 95: 10356-10360 (1998). 2 T.Y. Tsong, Biophysical Journal, 60: 297-306 (1991).