Selective anticancer effects of plasma-activated saline in 3D tumor model co-culturing of normal cells and cancer cells

Compared with conventional two-dimensional (2D) cell culture model, the 3D tumor model constructed in vitro is better representative of the tumor microenvironment in vivo. Here, we proposed the utilization of 3D tumor model of co-cultured cancer cells and normal cells to evaluate the selective anticancer effects of cold atmospheric plasma-activated saline (PAS), and expected to provide more precise information about PAS-tumor interactions. By cell sorting, we clarified that A375 melanoma cells and HaCaT normal skin cells purified from the 3D multicellular tumor model differ in sensitivity and responsiveness to PAS compared to the 2D culture model. And during the optimization of PAS treatment parameters, we further found that A375 cells were almost completely killed while HaCaT cells were still present in large numbers after 5 d of certain PAS treatment. Our experiment innovatively carries out the selective study of plasma technology in 3D co-culture system and provides a theoretical basis for further clinical and practical applications of PAS.