Free Radical Formation by the Peroxidase-Like Catalytic Activity of MFe2O4 (M = Fe, Ni and Mn) Nanoparticles

A.C. MORENO MALDONADO; E.L. WINKLER; M. RAINERI; A. TORO CORDOVA; L. RODRI­GUEZ; H. TROIANI; M.L. MOJICA PISCIOTTI; M. VASQUEZ MANSILLA; D. TOBIA; M. NADAL; T. TORRES; E. DE BIASI; C. RAMOS; G. GOYA; R. D. ZYSLER; E. LIMA JR

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Lugar: Washington; Año: 2019

1932-7447

Ferrite Magnetic Nanoparticles (MNPs) haveperoxidase-like activity and thus catalyze the decomposition of H2O2producing reactive oxygen species (ROS). Increasingly important applications ofthese Ferrite MNPs in biology and medicine require that their morphological,physicochemical and magnetic properties need to be strictly controlled. Usually,the tuning of their magnetic properties is achieved by the replacement of theFe by other 3d metals, such as Mn or Ni. Here, we studied the catalytic activityfor ferrite MNPs (MFe2O4, M = Fe2+/Fe3+,Ni, Mn) with mean diameter ranging from 10 to 12 nm. Peroxidase-like activitywas studied by Electron Paramagnetic Resonance (EPR) using the spin-trap DMPOat different pHs (4.8, 7.4) and temperatures (25°C, 40°C). We identified anenhanced amount of the hydroxyl (?OH) and perhydroxyl (?OOH) radicals for allsamples, compared to a blank solution. Quantitative studies show that [?OH] isthe dominant radical formed for Fe3O4, which is stronglyreduced with the concomitant oxidation of Fe2+ or its substitution(Ni or Mn). A comparative analysis of the EPR data against in vitro productionof ROS in microglial BV2 cell culture provided additional insight regarding thecatalytic activity of ferrite MNPs, which should be considered if biomedicaluses are intended. Our results contribute to understand the role of differentdivalent ions in the catalytic activity of Ferrite nanoparticles, which is veryimportance concerning their in biomedical applications.