CC BY 4.0 UnportedPiché, DominiqueTavernaro, IsabellaFleddermann, JanaLozano, Juan G.Varambhia, AakashMaguire, Mahon L.Koch, MarcusUkai, TomofumiHernández Rodríguez, Armando J.Jones, LewysDillon, FrankReyes Molina, IsraelMitzutani, MaiGonzález Dalmau, Evelio R.Maekawa, ToruNellist, Peter D.Kraegeloh, AnnetteGrobert, Nicole2020-01-142020-01-142019https://doi.org/10.34657/102https://oa.tib.eu/renate/handle/123456789/4831Extraordinarily small (2.4 nm) cobalt ferrite nanoparticles (ESCIoNs) were synthesized by a one-pot thermal decomposition approach to study their potential as magnetic resonance imaging (MRI) contrast agents. Fine size control was achieved using oleylamine alone, and annular dark-field scanning transmission electron microscopy revealed highly crystalline cubic spinel particles with atomic resolution. Ligand exchange with dimercaptosuccinic acid rendered the particles stable in physiological conditions with a hydrodynamic diameter of 12 nm. The particles displayed superparamagnetic properties and a low r2/r1 ratio suitable for a T1 contrast agent. The particles were functionalized with bile acid, which improved biocompatibility by significant reduction of reactive oxygen species generation and is a first step toward liver-targeted T1 MRI. Our study demonstrates the potential of ESCIoNs as T1 MRI contrast agents.enghttps://creativecommons.org/licenses/by/4.0/540cobalt ferrite nanoparticlesone-pot synthesismagnetic resonance imagingligand exchangecytotoxicityultrasmall nanoparticlesT1-weighted contrast agentliver targetingArticle