Adaptive Cold Atmospheric Plasma: Demonstration with In Vitro Cancer Treatment Experiments.

Cold atmospheric plasma (CAP) jets are ionized gases with a rich combination of reactive oxygen and nitrogen species, charged particles, and photons. It has been demonstrated the CAP is capable of eliminating cancer cells without damaging normal cells both in vitro and in vivo. However, obtaining a safe and reliable CAP treatment is challenging since the therapeutic effectiveness of the CAP treatment is affected not only by the CAP-generating parameters, such as discharge voltage and excited gas composition, but also by the surrounding environmental conditions, such as ambient temperature and humidity. Furthermore, even under the same treatment conditions, cancer cells may respond differently due to their stochastic nature. To address these challenges, this paper presents an adaptive CAP cancer treatment framework with real-time electrochemical impedance spectroscopy in situ diagnostics. Particularly, the EIS-based in situ diagnostics is studied with the canonical correlation analysis, where the correlation between impedance measurements and CAP treatment effectiveness, i.e., cell viability, is investigated. With an established correlation, real-time cell viability can be predicted with given impedance measurements. The capability of the proposed in situ diagnostics and adaptive plasma cancer treatment framework is evaluated with in vitro experiments under both nominal and perturbed treatment conditions.