During the initial phase of the NESTOR project, the Consortium successfully accomplished most of the planned advancements in the manufacture and evaluation of Magnetic Nanozymes (MNZs), spanning from atomistic modeling to catalytic applications and in vitro toxicity testing. Within WP1 (Synthesis of Metal-Oxide Nanozymes and Atomistic Modelling), the Consortium produced initial batches of nanozymes, leading to the selection of the most efficient catalysts based on their performance. This portfolio includes various iron-oxide-based MNZs with MFe2O4 spinel ferrite structures, where M represents Fe, Mn, Cu, Zn, and V. Notable compositions include VxFe3-xO4, FeO, Fe3O4, MnxFe3-xO4, and CuxFe3-xO4, synthesized collaboratively by CSIC, CNEA, CONICET, and UNIZAR.
These MNZs were rigorously tested for their catalytic activity under WP2 (Structural and Physicochemical Characterization of Nanozymes), focusing on factors such as the role of surface metal ions, their oxidation states, local symmetry, and surface functionalization under various environmental conditions. The Consortium advanced a comprehensive assessment involving structural and magnetic characterization techniques, utilizing several HRTEM-based analytical tools like STEM-HAADF, EELS, and Dual Beam analysis, as well as magnetometry, XPS, PIXE, and Neutron Diffraction. Significant secondments and training efforts were made during the first period, enhancing the skill set of involved ESRs and ERs in these cutting-edge techniques at large facilities like Institut Laue Langevin in Grenoble, France, and ALBA accelerator in Barcelona, Spain.
Moving forward, the refined portfolio of nanozymes forms the cornerstone of ongoing exploration into their biomedical and catalytic applications, with potential adjustments based on emerging data on enzymatic performance. Additionally, within WP3 (Free Radicals and ROS Generation) and WP4 (Toxicological Characterization in vitro), the catalytic performance of these nanozymes was evaluated through their ability to produce Reactive Oxygen Species (ROS) via Fenton and Haber-Weiss reactions. The findings provided insights into the production of hydroxyl (•OH) and hydroperoxyl radicals (•OOH), and the influence of nanoparticle size, surface coating, and metal doping on these processes.
From a management perspective related to WP5 (Management, Dissemination, Communication), the NESTOR project encountered some delays initially due to complications arising from the COVID-19 pandemic. This unforeseen circumstance led to a change in the Grant Agreement, resulting in a delayed start date of October 1, 2021. While the pandemic's impact has lessened over time, it continued to affect the execution of certain planned secondments. Furthermore, the project faced an unforeseen partner withdrawal due to a force majeure health condition, impacting the execution of secondments mostly related to WP3 and WP4.
