Nanosecond Pulsed Electric Field and Plasma Jets for Cancer Therapy

Nanosecond pulsed electric field (nsPEF) employs nanosecond-duration, high voltage pulses to induce oxidative stress, leading to temporary or permanent damage to cells or tissue (also known as reversible and irreversible electroporation), and has been considered a promising approach for cancer therapy. In parallel to this, nanosecond pulsed atmospheric pressure plasma jets (ns-APPJs) have also shown to be effective in inactivating cancer cells or increasing sensitivity of cells to electric fields. ns-APPJs are known to generate reactive chemical agents, including reactive oxygen and nitrogen species (RONS) which induces oxidative stress resulting in cell proliferation, apoptosis, and necrosis. In this dissertation, a novel impedance analysis technique was first presented based on measurements of the electrical properties of biological tissues including potato and an ex vivo tumor model. Studies of the effects of a nsPEF and ns-APPJ on biological cells and tissue were conducted, both as an individual treatment approach and a combined synergetic technology. While a nsPEF exhibits a dose dependent effect on pancreatic cancer cells (Pan02) in vitro, its combination with a ns-APPJ shows an enhance cancer cell inactivation with only moderate doses of both. In addition, the effects of the liquid conductivity on the ns-APPJ formation and the associated radical production were assessed to understand the underlying physics of plasma impinging on biological solutions.