Nanopore Formation in Neuroblastoma Cells

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Ultrashort or nanosecond electrical pulses (USEP) cause repairable damage to the ... paper, we use calcium uptake as an experimental endpoint to mark the ... actual image of the electrodes' position 50 µm above the cells. ... voltage power supply was set at 999 V, the maximum charging voltage (16.2 kV/cm electric field at ...
Nanopore Formation in Neuroblastoma Cells Following Ultrashort Electric Pulse Exposure Caleb C. Roth1, Jason A. Payne2, Gerald J. Wilmink2, Bennett L. Ibey2 General Dynamics Information Technology, Brooks City-Base, San Antonio, TX, USA 2 Radio Frequency Radiation Branch, Human Effectiveness Directorate, Air Force Research Laboratory, Brooks City-Base, San Antonio, TX, USA 1

. ABSTRACT Ultrashort or nanosecond electrical pulses (USEP) cause repairable damage to the plasma membranes of cells through formation of nanopores. These nanopores are able to pass small ions such as sodium, calcium, and potassium, but remain impermeable to larger molecules like trypan blue and propidium iodide. What remains uncertain is whether generation of nanopores by ultrashort electrical pulses can inhibit action potentials in excitable cells. In this paper, we explored the sensitivity of excitable cells to USEP using Calcium Green AM 1 ester fluorescence to measure calcium uptake indicative of nanopore formation in the plasma membrane. We determined the threshold for nanopore formation in neuroblastoma cells for three pulse parameters (amplitude, pulse width, and pulse number). Measurement of such thresholds will guide future studies to determine if USEP can inhibit action potentials without causing irreversible membrane damage. Key Words: Ultrashort Electrical Pulses, Electroporation, Neuroblastoma, Nanoporation

1. INTRODUCTION Ultrashort electrical pulses (USEP) or nanosecond electric pulses are defined as pulses with a pulse width (τ) less than 1 µs. The interaction between high voltage USEP and biological tissue has been studied for various applications including electromuscular incapacitation, cancer therapy, gene transfection, and pain suppression [1-7]. Previous work studying the impact of USEP on cell plasma membranes has shown that small pores (