Synthesized by soft chemistry techniques, iron oxide nanoparticles from maghemite ( γ - Fe2O3) and magnetite (Fe3O4) exhibit spinel inverse cubic structures. The particles have attracted much interest during the last years because of their superparamagnetic properties: in the size range 3 - 20 nm iron oxide single crystals carry a magnetic moment that fluctuate according to Néel/Brown rotational dynamics, and can be oriented by the application of a magnetic field. The talk will survey iron oxide magnetism related applications in nanoscience and nanomedicine [1,2].
Emphasis will be put on recent investigations performed with Magnetic Resonance Imaging (MRI) for non-invasive visualization of tissues and organs [5,6]. Wires can be remotely actuated using magnetic field and used as viscosity sensors for a wide variety of fluids, including living cells and biological fluids. The physics of the actuation mechanism will be disclosed .
 J.-F. Berret, A. Graillot, Versatile Coating Platform for Metal Oxide Nanoparticles: Applications to Materials and Biological Science, Langmuir, 38 (2022) 5323-5338.
 M. Safi, J. Courtois, M. Seigneuret, H. Conjeaud, J.-F. Berret, The Effects of Aggregation and Protein Corona on the Cellular Internalization of Iron Oxide Nanoparticles, Biomaterials, 32 (2011) 9353-9363.
 Q.L. Vuong, J.-F. Berret, J. Fresnais, Y. Gossuin, O. Sandre, A Universal Scaling Law to Predict the Efficiency of Magnetic Nanoparticles as MRI T2-Contrast Agents, Adv. Healthc. Mater., 1 (2012) 502-512.
 G. Ramniceanu, B.T. Doan, C. Vezignol, A. Graillot, C. Loubat, N. Mignet, J.-F. Berret, Delayed Hepatic Uptake of Multi-Phosphonic Acid Poly(Ethylene Glycol) Coated Iron Oxide Measured by Real-Time Magnetic Resonance Imaging, RSC Adv., 6 (2016) 63788-63800.
 J.-F. Berret, Local Viscoelasticity of Living Cells Measured by Rotational Magnetic Spectroscopy, Nat. Commun., 7 (2016) 10134.
 L.-P.-A. Thai, F. Mousseau, E. Oikonomou, M. Radiom, J.-F. Berret, Effect of Nanoparticles on the Bulk Shear Viscosity of a Lung Surfactant Fluid, ACS Nano, 14 (2020) 466-475.