Effects of a non-thermal plasma needle device on HPV-16 positive cervical cancer cell viability in vitro

Non-thermal atmospheric pressure plasma has been demonstrated to inactivate a wide range of surface-dwelling pathogenic microorganisms including airborne viral particles, vegetative bacteria and bacterial spores. This shows the promise of plasma-based decontamination procedures for broad-spectrum sterilization and disinfection and promotes the in-depth and systematic study of how plasma treatment conditions relate to pathogen inactivation efficiency. A wide knowledge gap nonetheless exists regarding whether certain plasma parameters and exposure conditions can alter the resistance of virus-linked cancer cells to treatment. The current work reveals the effects of a non-thermal needle-shaped atmospheric-pressure plasma on the viability of an adherent human cervical carcinoma cell line containing a human papillomavirus type 16 (HPV-16) provirus. Using a helium plasma device driven by 8 kV, 2 kHz, 150 ns pulses, CaSki cells moistened with culture medium were exposed to plasma for different treatment durations, gap distances and gas flow rates. Open-well exposure to helium flow alone for 120 s did not produce significant changes in CaSki cell viability. By comparison, cells exposed to plasma showed a dose-dependent reduction in viability from at least 15% to 60% compared to the control. These findings reveal possibilities for NTP treatment of HPV-16 infected cervical cancers and indicate the importance of NTP parameters to treatment outcome.