Probing thermal and solvent effects on hyperfine interactions and spin relaxation rate of δ-FeOOH(100) and [MnH3buea(OH)]2-: toward new MRI probes

Abstract

Cancer is a global epidemic, which significantly affects all ages and socio-economic groups and one reason is the great difficulty of the initial diagnostic phase. The Magnetic Resonance Imaging (MRI), through effective contrast agents, has greatly helped in the diagnosis at the initial stage. Recently, superparamagnetic iron oxide nanoparticles and complexes with Mn2+ have received great attention due to their applications as contrast agents for Magnetic Resonance Imaging (MRI). Those materials can shorten the T2 and T2∗ transverse relaxation times. Thus, in this work, the face 100 of the δ-FeOOH and the complex [MnH3buea(OH)]2− were studied with explicit water molecules in order to obtain the 1H and 17O hyperfine coupling constants (HFCCs). Molecular dynamics (MD) simulations were performed using the ReaxFF program for subsequent statistical inefficiency calculations. Thus, the structures from the MD simulation were selected for HFCC calculations. The theoretical results suggest that the δ-FeOOH and [MnH3buea(OH)]2− considerably increase the 1H and 17O hyperfine coupling constants of the water molecules. In addition, δ-FeOOH is sensitive to 1H and 17O HFCCs parameters, however, in the complex [MnH3buea(OH)]2−, 17O is much more sensitive than 1H in relation to the HFCC parameters. Our findings point out δ-FeOOH as a promising alternative to conventional contrast agents.