(439b) Using Gold Nanoshells to Enhance Electroporation and Uptake Through the Cell Membrane

                                                                                    Alisha D. Peterson, Mark J. Jaroszeski, and Vinay K. Gupta

                                                                            Department of Chemical & Biomedical Engineering, University of South Florida

Electroporation is a technique in which an external electric field is applied across a cell membrane. The applied field causes a disruption in the membrane creating pores, which ultimately allows for an increase in uptake of the surrounding media by the cell.  The technique of electroporation has been studied for various applications including gene delivery and drug delivery. However, a continuing challenge is to enhance the delivery rates as well as the types of therapeutic agents that need to be delivered.  In this context, gold nanoshells can form the basis of enhancing electroporation of the cell membrane. Gold nanoshells are nanoscale particles composed of a silica core and a thin gold shell.  These particles are of great interest due to their unique and tunable optical properties, large surface area, and ability to heat locally.  Nanoshells are being currently studied for applications in tumor imaging, drug delivery, and tumor ablation. Our research focuses on combining the conductive properties of gold nanoshells with the electroporation technique to enhance cellular uptake of therapeutic agents. The goal is to amplify the effects of the electric field on the cell membrane in order to increase permeability. Concurrently, the nanoshells can also serve as the carriers for delivery of the therapeutic agents by attach the biomolecules to the nanoshell surface. In this presentation we will present results from two phases of our research.  First, the synthesis and characterization of gold nanoshells will be discussed. Secondly, the use of these nanoshells in electroporation of fibroblast cells (a model system) will be discussed.  The influence of gold nanoshells on in-vitro cellular uptake of Sytox Green, an amino acid stain, will be shown.  Results from the interplay of parameters such as voltage amplitude, number of electric pulses, pulse length, and ratio of particles to cells concentration will be presented.