4. MSN for MRI

Magnetic resonance imaging (MRI) is a non-invasive diagnostic tool that not only provides high-resolution anatomical images, but also enables pathogenesis to be diagnosed by measuring biomarkers. Nevertheless, commonly used MRI contrast agents are mainly small molecules (gadolinium chelates) which are not sufficiently sensitive and often do not provide satisfactory contrast enhancement for imaging early stages of disease. Magnetic resonance contrast agents in nanoparticle form are generally much more sensitive, thanks to enhanced relaxation and a large number of active magnetic centers.

W. Lin et al. [30][31] have shown that the accessibility of magnetic centers to water molecules is the important element for creating effective MRI contrast agents,...