Abstract
To date, the main two classes of clinically used contrast agents for magnetic resonance imaging (MRI) are soluble paramagnetic gadolinium chelates and superparamagnetic iron oxide particles. While iron oxides predominantly increase T2-relaxivity and thus provide negative contrast, gadolinium chelates are often requested as they increase T1-relaxivity and enhance positive contrast. As particulate contrast agents are preferable due to a more favorable signal-to-noise ratio, the goal of our present work was the development of poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles labeled with chelated gadolinium.