Impact of Ambient Gas Composition of Argon Plasma Jet on Pam Composition and Cancer Cell Viability

Reactive oxygen and nitrogen species (RONS) are known to have several biological activities, with multiple potential applications, including cancer therapy. Present study investigated the differential effect of plasma-produced reactive oxygen (ROS) and nitrogen (RNS) species on cancer cell viability. ROS and RNS were generated in deionized water using atmospheric pressure Ar plasma jet operating in the controlled ambient gases (air, O
2
or N2) which allowed to generate plasma-activated medium (PAM) containing only ROS (O
3
, H
2
O
2
) or both ROS and RNS
$(\mathrm{H}_{2}\mathrm{O}_{2},\ \mathrm{N}\mathrm{O}_{2}^{-},\ \mathrm{N}\mathrm{O}_{3}^{-})$
. The concentrations of O
2
, O
3
, H
2
O
2
,
$\mathrm{N}\mathrm{O}_{2}^{-}$
and
$\mathrm{N}\mathrm{O}_3^{-}$
were determined using UV absorption spectroscopy. H
2
O
2
was produced in all ambient gases, its generation rate was higher in air or N2 and lowest in O
2
. Small quantities of
$\mathrm{N}\mathrm{O}_{2}^{-}$
were generated during short (<5 min) plasma treatment in air and N2. The highest amount of
$\mathrm{N}\mathrm{O}_3^{-}$
was generated in ambient N2 gas, with its production rate nearly proportional to the treatment time. Finally, ozone was generated only in the case of ambient O
2
.