Long‐Term Dynamics of Nitric Oxide Radicals in Plasma‐Activated Ringer's Lactate Solution

ABSTRACT Medical applications of atmospheric pressure plasmas, including in cancer therapy, have attracted growing interest. Although ·NO in plasma‐activated Ringer's lactate (PAL) solutions have been reported to exhibit selective cancer‐killing effects, its radical dynamics during such treatments remains unclear due to the short lifetimes. The present study investigated the dynamics of ·NO in PAL solutions using electron spin resonance spectroscopy and fluorescence staining under varied plasma conditions. The results indicate the long‐term generation of ·NO in PAL solutions over 6 h. The simultaneous presence of HNO 2 , H 2 O 2 and O 3 in that solution may play a crucial role in the generation of ·NO. These findings suggest that PAL solutions could function as sustainable ·NO sources, potentially enhancing the effectiveness of plasma‐based therapies.