A Novel Method for Estimating the Dosage of Cold Atmospheric Plasmas in Plasma Medical Applications

Cold atmospheric plasmas (CAPs) used in plasma medicine have shown great potential in various aspects including wound healing, dermatology, cancer therapy, etc. It is one of the important issues to determine the plasma dosage in plasma medicine because it dominates the specific plasma treatment results. However, the multi-process interactions between CAPs and biological materials make it rather challenging to give an accurate and versatile definition for plasma dosage. In this study, the ratio of the discharge energy to the number of the treated in vitro kidney cells (mJ/cell) was employed as the unit of the plasma dosage. Additionally, inspired by basic knowledge of pharmacy, the median lethal dose (LD50) was employed to help estimate the plasma dosage. The experimental results show that the value of LD50 using the newly designed CAP Bio-Med Platform for the kidney cells is 34.67 mJ/cell. This biology-based method has the advantages of easy operation, independence of specific CAP sources, and also independence of complex interactions between CAPs and the treated biological targets, and consequently, may provide a new direction to quantitatively define the plasma dosage in various plasma medical applications.