Fluorinated Mesoporous Silica Nanoparticles for Binuclear Probes in 1H and 19F Magnetic Resonance Imaging

When combined with 1H MRI, 19F MRI has the potential to combine high-resolution anatomical information with quantitative diagnostic. In this study, we report on the development of fluorinated mesoporous silica nanoparticles (MSNs), as dual 1H and 19F MRI probes. For this, MSNs were synthesised and covalently functionalized either with fluorosilane (FMSNs) or polyfluorosiloxane (polyFMSNs). Gadolinium chelates were also grafted on the particles, in order to confer 1H-MRI contrast enhancement to the imaging probes. Thus-treated nanoparticles were fully characterized and their 1H/19F relaxometric performances were thoroughly measured and compared. The 19F relaxation properties were found to be dependent on the concentration of fluorine; they were also highly sensitive to the presence of gadolinium. Better relaxivities were obtained with polyFMSNs, in comparison with those of FMSNs, leading to better 19F MRI sensitivity. Strong 1H relaxometric properties were also obtained for both nanoparticle systems, at la...