Effects of Non-Thermal Plasma on Mammalian Cells

TLDR

Thermal plasmas and lasers are used in medicine for heat‑based tissue ablation, whereas non‑thermal plasma offers heat‑free, potentially selective effects. The study aims to elucidate the mechanisms by which non‑thermal plasma interacts with living tissues to support clinical uses such as wound healing, sterilization, coagulation, and cancer therapy. Non‑thermal plasma generated by dielectric barrier discharge induces dose‑dependent cellular responses ranging from proliferation to apoptosis, primarily through intracellular ROS that trigger DNA damage marked by γ‑H2AX phosphorylation (ATR‑dependent, ATM‑independent), causing replication arrest or single‑strand breaks without forming bulky adducts.

Abstract

Thermal plasmas and lasers have been widely used in medicine to cut, ablate and cauterize tissues through heating; in contrast, non-thermal plasma produces no heat, so its effects can be selective. In order to exploit the potential for clinical applications, including wound healing, sterilization, blood coagulation, and cancer treatment, a mechanistic understanding of the interaction of non-thermal plasma with living tissues is required. Using mammalian cells in culture, it is shown here that non-thermal plasma created by dielectric barrier discharge (DBD) has dose-dependent effects that range from increasing cell proliferation to inducing apoptosis. It is also shown that these effects are primarily due to formation of intracellular reactive oxygen species (ROS). We have utilized γ-H2AX to detect DNA damage induced by non-thermal plasma and found that it is initiated by production of active neutral species that most likely induce formation of organic peroxides in cell medium. Phosphorylation of H2AX following non-thermal plasma treatment is ATR dependent and ATM independent, suggesting that plasma treatment may lead to replication arrest or formation of single-stranded DNA breaks; however, plasma does not lead to formation of bulky adducts/thymine dimers.