Prussian blue nanoparticles as isotope-labeled and fluorescent contrast material.

The study presents the synthesis and development of a Prussian Blue based biocompatible and chemically stable T1 magnetic resonance imaging (MRI) contrast agent with near infrared (NIR) optical contrast for preclinical application. The physical properties of the Prussian blue nanoparticles (PBNPs) (iron (II); iron (III); octadecacyanide) were characterized with dynamic light scattering (DLS), zeta potential measurement, atomic force microscopy (AFM), and transmission electron microscopy (TEM). In vitro contrast enhancement properties of PBNPs were determined by MRI. In vivo T1-weighted contrast of the prepared PBNPs was investigated by MRI and optical imaging modality after intravenous administration to mice. PBNP-s doped with 201Tl isotope have also been synthetised and biodistribution in mice was determined by using SPECT and MRI. Activity concentrations (MBq/cm3) were calculated from the SPECT scans for each dedicated volume of interest (VOI) of liver, kidneys, salivary glands, heart, lungs, and brain. Isotope-labeled citrate-coated PBNP accumulation peaked at 2 hours after injection in the kidneys and the liver followed by a gradual decrease in activity in later time points. We synthesized, characterized, and radiolabeled a Prussian blue-based nanoparticle platform for contrast material applications. In vivo radiochemical stability and biodistribution open up the way for further diagnostic applications. The presence and detectability of PBNPs during initial biodistribution in the cardiovascular system indicates vascular contrast material applications, too.