Cold Atmospheric Plasma: Mechanism & Biology
Cold Atmospheric Plasma (CAP) is a non-equilibrium ionised gas comprising electrons, ions, reactive oxygen and nitrogen species (RONS), photons and localised electric fields.
Reactive species are generated via electron interactions with oxygen and water vapour, producing ROS (e.g. OH, O3, H2O2) and RNS (e.g. NO, NO2−, NO3−).
At the plasma–tissue interface, effects are surface-initiated and mediated via biochemical signalling rather than direct electron penetration.
Primary mechanisms include redox signalling, inflammation modulation, microcirculation effects via nitric oxide pathways, and antimicrobial activity.
CAP creates an oxidative environment affecting bacteria, fungi and viruses at the surface.
References:
Danby, S., & Cork, M. (2013). The effects of pimecrolimus on the innate immune response in atopic dermatitis. British Journal of Dermatology, 168(2), 235–236. https://doi.org/10.1111/bjd.12154
Fridman, G., Friedman, G., Gutsol, A., Shekhter, A. B., Vasilets, V. N., & Fridman, A. (2008). Applied plasma medicine. Plasma Processes and Polymers, 5(6), 503–533. https://doi.org/10.1002/ppap.200700154
Graves, D. B. (2012). The emerging role of reactive oxygen and nitrogen species in redox biology and some implications for plasma applications to medicine and biology. Journal of Physics D Applied Physics, 45(26), 263001. https://doi.org/10.1088/0022-3727/45/26/263001
Ikawa, S., Tani, A., Nakashima, Y., & Kitano, K. (2016). Physicochemical properties of bactericidal plasma-treated water. Journal of Physics D Applied Physics, 49(42), 425401. https://doi.org/10.1088/0022-3727/49/42/425401
Isbary, G., Heinlin, J., Shimizu, T., Zimmermann, J., Morfill, G., Schmidt, H., Monetti, R., Steffes, B., Bunk, W., Li, Y., Klaempfl, T., Karrer, S., Landthaler, M., & Stolz, W. (2012). Successful and safe use of 2 min cold atmospheric argon plasma in chronic wounds: results of a randomized controlled trial. British Journal of Dermatology, 167(2), 404–410. https://doi.org/10.1111/j.1365-2133.2012.10923.x
Kong, M. G., Kroesen, G., Morfill, G., Nosenko, T., Shimizu, T., Van Dijk, J., & Zimmermann, J. L. (2009). Plasma medicine: an introductory review. New Journal of Physics, 11(11), 115012. https://doi.org/10.1088/1367-2630/11/11/115012
Von Woedtke, T., Schmidt, A., Bekeschus, S., Wende, K., & Weltmann, K. (2019). Plasma Medicine: a field of applied redox biology. In Vivo, 33(4), 1011–1026. https://doi.org/10.21873/invivo.11570