In vivo Plasma Gun applications : from plasma delivery to therapeutic action
Résumé
Brief overview of in vivo antitumor applications performed with the Plasma Gun [1] will be first proposed. They include orthotopic colon and pancreas treatments, comparison of plasma gun action with state of the art pancreas chemotherapeutic delivery in separate or combined protocols [2] and recently reported new cancer treatment approach strategy based on tissue oxygenation and blood flow regulation during and after plasma jet delivery [3]. Besides these very encouraging results, the various potentialities for in situ plasma delivery with the Plasma Gun, including challenging endoscopic protocols, and the evidence for the critical role of reactive species (RS) to trigger apoptosis, there still exists a large debate on the specific role of each of the plasma jet components, including chemical, electrical and radiative agents. In a second part of the presentation, emphasis will be given on two critical topics necessarily involved in any plasma jet biomedical applications: the first consists in the major influence of the target over which plasma jet impingement occurs. It has been shown that depending on the conductivity of the target, secondary plasma generation occurs from the target, leading to a critical modification of the RS generation. Preliminary results obtained during in situ OH radical LIF diagnostics and ICCD plasma imaging experiments confirm the influence of the properties of different water targets. The second main issue concerns the strong interplay between the rare gas flow (in most case helium, argon or neon) and the plasma species generated during plasma jet ionization wave propagation. Drastic modification of the rare gas flow features have been recently evidenced and characterized through Schlieren visualization, pressure measurements and ICCD imaging [4]. It must finally be pointed out that both plasma-induced gas flow modification and target nature influence play a simultaneous role during biomedical application with plasma jets. Acknowledgments: This work is supported by the APR Region Centre PLASMEDNORM and ANR 2010 BLAN 093001 PAMPA. [1] Robert E, Sarron V, Riès D, Dozias S, Vandamme M and Pouvesle J M 2012 Characterization of pulsed atmospheric-pressure plasma streams (PAPS) generated by a plasma gun Plasma Sources Sci. Technol. 21 034017. [2] Brulle L, Vandamme M, Riès D, Martel E, Robert E, Lerondel S, Trichet V, Richard S, Pouvesle J M and Le Pape A 2012 Effects of a non thermal plasma treatment alone or in combination with Gemcitabine in a MIA PaCa2-luc orthotopic pancreatic carcinoma model. Plos one 7 (12) e52653. [3] Collet G., Robert E., Lenoir A., Vandamme M., Darny T., Dozias S., Kieda C. and Pouvesle J.M. 2014 Plasma jet−induced tissue oxygenation: potentialities for new therapeutic strategies Plasma Sources Sci. Technol. 23 0120005. [4] Robert E., Sarron V., Darny T., Riès D., Dozias S., Fontane J., Joly L. and Pouvesle JM 2014 Rare gas flow structuration in plasma jet experiments Plasma Sources Sci. Technol. 23 0120003.