Synergistic induction of immunogenic cell death in triple-negative breast cancer cells by cold atmospheric plasma and pulsed electric field.

This study aimed to investigate the synergistic effect of cold atmospheric plasma (CAP) and pulsed electric field (PEF) in inducing immunogenic cell death (ICD) in triple-negative breast cancer (TNBC) cells. CAP and PEF devices were self-developed. MDA-MB-231 cell line was used and divided into five groups: Control, CAP, PEF, CAP before PEF, and PEF before CAP. Optical emission spectroscopy confirmed that CAP produced reactive species such as He, OH, N₂ and O, and infrared thermal imaging showed that the maximum temperature during the treatment did not exceed 28.3 °C. CAP could significantly increase the content of H₂O₂, NO₂- and NO₃- in PBS. Scavenger experiments showed that the cytotoxicity of CAP was completely reversed by Catalase and N-Acetylcysteine (NAC), while that of PEF was only reversed by NAC. Furthermore, CAP before PEF treatment had the strongest killing and pro-apoptotic effects on TNBC cells, and the increase in ICD markers was the most significant. Mechanically, pre-treatment with CAP allowing PEF to cause more extensive membrane disintegration. CAP before PEF treatment also triggered the most intense mitochondrial oxidative stress, leading to a significant rise in intracellular reactive oxygen species (ROS) levels.