Material-cell interactions: From nanoparticles to conducting polymers

MEMs Seminar - Christine Payne Associate Professor School of Chemistry and Biochemistry Georgia Tech
Friday, 21 April 2017 - 11:30am
203 Teer Building

The goal of research in the Payne Lab at Georgia Tech is to understand how cells and proteins interact with nanoscale materials and then use this understanding to control cellular properties. This talk will focus on two new areas of research. First, we have recently shown that titanium dioxide nanoparticles, widely used as photocatalysts and white pigments, lead to a unique oxidative stress response in human cells in the absence of UV light. Specifically, expression of the peroxiredoxin family of anti-oxidant enzymes is altered following incubation with relatively low concentrations of TiO2 nanoparticles. Using a combination of spectroscopic methods (XPS, EPR, fluorescence), we have found that this oxidative stress response is mediated by the nanoparticle-induced oxidation of the layer of proteins that adsorb non-specifically of the nanoparticles, demonstrating the importance of this protein “corona” in nanoparticle-cell interactions. Second, the Payne Lab has developed conducting polymer nano- and microwires to control the electrical properties of single cells. These wires, electrochemically synthesized from PEDOT:PSS with a Young’s modulus of ~2 GPa, are expected to be less invasive than current metal or silicon devices. Examples will illustrate the use of these conducting polymer wires to control the action potentials of cardiomyocytes and the resting membrane potential of bacteria.