title: Rapid Nucleation of Iron Oxide Nanoclusters in Aqueous Solution by Plasma Electrochemistry.
abstract: Progresses in cold atmospheric plasma technologies have made possible the synthesis of nanoparticles in aqueous solutions using plasma electrochemistry principles. In this contribution, a reactor based on microhollow cathodes and operating at atmospheric pressure was developed to synthesize iron-based nanoclusters (nanoparticles). Argon plasma discharges are generated at the tip of the microhollow cathodes, which are placed near the surface of an aqueous solution containing iron salts (FeCl2 and FeCl3) and surfactants (biocompatible dextran). Upon reaction at the plasma-liquid interface, reduction processes occur and lead to the nucleation of ultrasmall iron-based nanoclusters (IONCs). The purified IONCs were investigated by XPS and FTIR, which confirmed that the nucleated clusters contain a highly hydrated form of iron oxide, close to the stoichiometric constituents of α-FeOOH (goethite) or Fe5O3(OH)9 (ferrihydrite). Relaxivity values of r1 = 0.40 mM(-1) s(-1) and r2/r1 = 1.35 were measured (at 1.41 T); these are intermediate values between the relaxometric properties of superparamagnetic iron oxide nanoparticles used in medicine (USPIO) and those of ferritin, an endogenous contrast agent. Plasma-synthesized IONCs were injected into the mouse model and provided positive vascular signal enhancement in T1-w. MRI for a period of 10-20 min. Indications of rapid and strong elimination through the urinary and gastrointestinal tracts were also found. This study is the first to report on the development of a compact reactor suitable for the synthesis of MRI iron-based contrast media solutions, on site and upon demand.
authors.affiliation: †Axe Médecine Régénératrice, Centre Hospitalier Universitaire (CHU) de Québec, 10 rue de l'Espinay, Québec, G1L 3L5, Canada.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Bouchard
authors.affiliation: †Axe Médecine Régénératrice, Centre Hospitalier Universitaire (CHU) de Québec, 10 rue de l'Espinay, Québec, G1L 3L5, Canada.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Létourneau
authors.affiliation: †Axe Médecine Régénératrice, Centre Hospitalier Universitaire (CHU) de Québec, 10 rue de l'Espinay, Québec, G1L 3L5, Canada.
authors.forename: Christian
authors.initials: C
authors.lastname: Sarra-Bournet
authors.affiliation: †Axe Médecine Régénératrice, Centre Hospitalier Universitaire (CHU) de Québec, 10 rue de l'Espinay, Québec, G1L 3L5, Canada.
authors.forename: Myriam
authors.initials: M
authors.lastname: Laprise-Pelletier
authors.affiliation: †Axe Médecine Régénératrice, Centre Hospitalier Universitaire (CHU) de Québec, 10 rue de l'Espinay, Québec, G1L 3L5, Canada.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Turgeon
authors.affiliation: †Axe Médecine Régénératrice, Centre Hospitalier Universitaire (CHU) de Québec, 10 rue de l'Espinay, Québec, G1L 3L5, Canada.
authors.forename: Pascale
authors.initials: P
authors.lastname: Chevallier
authors.affiliation: †Axe Médecine Régénératrice, Centre Hospitalier Universitaire (CHU) de Québec, 10 rue de l'Espinay, Québec, G1L 3L5, Canada.
authors.forename: Jean
authors.initials: J
authors.lastname: Lagueux
authors.affiliation: †Axe Médecine Régénératrice, Centre Hospitalier Universitaire (CHU) de Québec, 10 rue de l'Espinay, Québec, G1L 3L5, Canada.
authors.forename: Gaétan
authors.initials: G
authors.lastname: Laroche
authors.affiliation: †Axe Médecine Régénératrice, Centre Hospitalier Universitaire (CHU) de Québec, 10 rue de l'Espinay, Québec, G1L 3L5, Canada.
authors.forename: Marc-A
authors.initials: MA
authors.lastname: Fortin
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000138:chemical synthesis / Q000737:chemistry* / Q000493:pharmacokinetics; D055664:Electrochemical Techniques; D005290:Ferric Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000493:pharmacokinetics; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D012996:Solutions; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D003287:Contrast Media; D005290:Ferric Compounds; D012996:Solutions; D014867:Water; C000499:ferric oxide