Analysis of Electrical Characteristics of Living Cells Exposed by Cold Atmospheric Plasma using the Equivalent Circuit Model

Multiple factors are involved in plasma medicine, but the balance of their influence and interaction have not been understood well. Therefore, the purpose of this study is to clarify the basic mechanisms of plasma medicine by focusing on the interaction with cells through the supply of electric field and charge, apart from the chemical reactions of reactive species that have been studied. Analysis of the electronic behavior of surface charging and membrane potential changes could reveal the mechanism of membrane transport. In this paper, the equivalent circuit is analyzed considering the situation where plasma is directly irradiated to a single cell. The resistance and capacitance were derived from references for the cell and from our previous data of fluid analysis for the plasma. The gas-phase gap is 2 mm and the applied voltage is 30 kV. The discharge generated is the atmospheric pressure Townsend-like discharge with an electron density of about 10^-8 cm^-3. In addition, the voltage and current applied to the membrane were deduced quantitatively. The maximum voltage of 5.8 mV was applied to the membrane. This is about half of the voltage applied to the entire cell. Under these conditions, the voltage had no significant influence on the membrane such as destructive damage.