Xin Hu1, Andrew Morss2, Brian E. Henslee3, Wei-Ching Liao4, Shengnian Wang5, Gregory Lafyatis2, and Ly James Lee3. (1) NSEC center for Affordable Nanoengineering of Polymer Biomedical Devices (CANPBD), The Ohio State University, Room 125A, 140 West 19th Ave., Columbus, OH 43210, (2) Department of Physics, The Ohio State University, Columbus, OH 43210, (3) Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210, (4) Mechanical Engineering, The Ohio State University, Columbus, OH 43210, (5) Institute for Micromanufacturing, Louisiana Tech University, 911 Hergot Avenue, Ruston, LA 71272
As an effective non-viral method in gene delivery, cell electroporation applies an external electric field to temporarily increase the permability of the cell membrane. Currently, there are two types of cell electroporation, i.e., the bulk and single cell electroporations. The efficiency of the single cell electroporation is higher because it can precisely control the electric field distribution around the single cell. But the effect of electric field on a multi-cell system hasn't been fully understood yet, especially when the system is in a complex geometry. We use both experiment and simulation to study the effect of external electric field on a system with two or more cells in a complex contraction/expansion microchannel, which can focus the electric field near the area of smallest cross-section. By using charged tracing particles, we are able to draw the electric field lines in this multi-cell system. This also enables us to calculate the value of the electric conductivity of the cell. Both the experiment and simulation show that the distribution of the electric field varies when the relative position of cells changes. This study can be used to guide us to increase the efficiency of the bulk electroporation.