Tuning the Synergistic Interplay between Clinical MRI Contrast Agents and MR-Active Metal-Organic Framework Nanoparticles

Enhancing contrast agent visibility in magnetic resonance imaging (MRI) is a long existing challenge. Here, we address this challenge by embedding a well-known contrast agent within highly porous MR-active metal-organic framework (MOF) nanoparticles. Creating a confined MR-active environment for the contrast agent synergistically increases the overall relaxivity. In order to study this effect and relate it to the physicochemical properties of the nanoparticles, we introduce a method based on statistical analysis using a multiparametric linear model. This methodology reveals that the amount of embedded contrast agent dominates over other physicochemical properties, potentially relevant for MRI. The suggested approach is generally applicable for the investigation of other new MR-active nanoparticles and allows for the investigation of interplaying factors. Furthermore, the improved MRI visualization of the MOF nanoparticles may facilitate their further development as a flexible and versatile nanocarrier platform for theranostic applications.