Plasma jet as a source of carbon monoxide (CO) for biomedical applications

Abstract

International audienceCarbon monoxide (CO) has a bad reputation due to the potentially lethal consequences when inhaled at high concentrations. However, at low doses CO appears to have many beneficial effects for human health and has a broad spectrum of biological activities such as anti-inflammatory, vasodilatory, anti-apoptotic, and anti-proliferative effects [1]. Plasma can generate CO from the dissociation of CO2, and in this context, non-equilibrium plasma at atmospheric pressure is an attractive in situ CO source, since it is able to create CO at low doses from CO2 [2]. Moreover, plasma can be used for biomedical applications and intense research is now being conducted on the potential therapeutic use of plasma for the treatment of different pathologies including cancer and skin wounds. Plasmas are very versatile as they possess the capacity to generate large amounts of reactive species combined with electric field, photons and charged particles. However, the combination of plasma and CO for biomedical applications remains to be fully explored. This presentation will focus on the challenge to develop a plasma reactor to generate controlled quantities of CO that can be used for therapeutic purposes. The reactor is based on plasma jet configuration where the discharge is produced in a coaxial dielectric barrier discharge (DBD) reactor equipped with a quartz capillary tube [3]. Helium with small addition of CO2 goes through the device. To assess and quantify the production of CO from plasma, we developed a system whereby mouse blood hemoglobin, a strong scavenger of CO, interacted with the plasma reaction. Once CO binds to hemoglobin, it forms carboxyhemoglobin (COHb), which can be precisely quantified by light absorption. We will present the first results showing that an indirect and a direct plasma treatment have a different influence on the production of CO and its binding to hemoglobin. [1]B. E. Mann and R. Motterlini, Chem. Commun., no. 41, p. 4197, 2007.[2]E. Carbone and C. Douat, Plasma Med., vol. 8, no. 1, pp. 93–120, 2018.[3]T. Darny, J.-M. Pouvesle, V. Puech, C. Douat, S. Dozias, and E. Robert, Plasma Sources Sci. Technol., vol. 26, no. 4, p. 045008, Mar. 2017