Tracking UV photolysis and molecular transport induced chemical changes within tissue models treated with a cold atmospheric pressure plasma jet

Cold atmospheric plasma jets operated into ambient air provide a rich source of reactive oxygen and nitrogen species (RONS), which are known to influence biological processes important in disease. Despite plasma shown to have effects deep within tissue (e.g. destruction of subcutaneous cancer tumors), it is not understood how the plasma RONS can reach deep-seated diseased cells. In this study, we model the plasma jet delivery of RONS into a tissue target and we delineate two processes: through target delivery of RONS generated (primarily) in the plasma jet and in situ RONS generation by UV photolysis within the target. RONS are rapidly generated in the tissue target’s surface by UV photolysis. Once in the target, RONS are transported to millimeter depths via a slower molecular process