Study on the anticancer area and depth of a He plasma jet based on 2D monolayer cells and 3D tumor spheroids

The application of cold atmospheric plasma jet in cancer treatment has received extensive attention. Research on the spatial distribution of the anticancer effects induced by plasma jet is of great significance for further promoting its clinical application. Here, based on two-dimensional monolayer cells and three-dimensional (3D) multicellular tumor spheroids, the distributions of anticancer effects induced by He plasma jet irradiation on tumor tissue were studied in detail. It was found that the effective anticancer area of the plasma jet was affected by the gas flow rate. Further studies showed that the plasma jet caused physical damage in the central region of the anticancer area and induced apoptosis in the peripheral region due to the reactive oxygen species (ROS) generated by the plasma jet. In addition, the anticancer results on 3D multicellular tumor spheroids indicated that the apoptosis rate and the anticancer depth of the plasma jet were different at different distances from the plasma-irradiated spot. This study could help us better understand the actual anticancer effects of a plasma jet on living tumor tissues, and it may provide beneficial information for optimizing the plasma jet treatment method in future clinical applications.