Peroxidase catalytic activity of iron oxide nanoparticles and its effect on biological systems

A.C. MORENO MALDONADO; E.L. WINKLER; M. RAINIERI ANDERSEN; A. ALFONSO TORO CÓRDOVA; L. RODRÍGUEZ; H.E. TROIANI; M.L. MOJICA PISCIOTTI; M. VASQUEZ MANSILLA; C.A. RAMOS; G.F. GOYA; R.D. ZYSLER; E. LIMA JR.

Gijón

Congreso; International Conference on Fine Particle Magnetism (ICFPM19); 2019

International Conference on Fine Particle Magnetism (ICFPM19)

The potential applications of ferrite nanoparticles in biology and medicine have been widely studied in the last decade. Most research are been devoted in the use of these nanoparticles in oncologic treatmentsbased in the magnetic fluid hyperthermia (MFH) and the drug delivery. Although MFH has been aninteresting promise for tumor treatment, until now it has only been used in a complementary way with other traditional treatments such as radiotherapy and chemotherapy, since tumor reduction has not been achieved solely with the heating of the particles. Recently, as the nanoparticles can be multifunctional, the idea to combine different properties of these nanostructures has been generalized. In this area, theranostics nanomedicine is an emerging field where diagnosis and treatment are combined using the same material.The iron oxide nanoparticles have the ability to catalyze the peroxidase activity by Fenton's reaction. This reaction is known since the late nineteenth century, and consists in an oxidative reaction where Fe+2 and Fe+3 ions catalyze a peroxidase-like reaction with the production of free radicals (Reactive Oxygen Species - ROS). These radicals can cause cell death, and can be used in cancer treatments combined with the hyperthermia treatment.Here we identify and quantify, by Electron Paramagnetic Resonance (EPR), the formation of freeradicals by the catalytic activity of different ferrite nanoparticles. EPR using the spin-trap DMPO allows analyze the concentration of OHo and OOHo produced by each nanoparticles system as function of time. In particular, we have analyzed the reaction produced by Fe3O4, its oxidized phase (γ-Fe2O3), and Mn and Ni ferrites nanoparticles. Our results clearly show that the catalytic activity depends on the nanoparticles composition, varying the specific radical formation as well as the total amount of radicals. We have also found that, as in all catalytic activity, the free radicals production depends on the nanoparticles surface/volume ratio. On the other hand, this activity also depends on the symmetry of the environment of the Fe+2 and Fe+3 ions.The EPR identification and quantification of free radical was contrasted with the results of ROS formation, measured by photoluminescence, in in-vitro experiments using BV2 cells. Finally, we will discuss the future perspectives of this multifunctional behavior of the nanoparticles in different applications in nanomedicine.