Nanocapsules Synthesized by Miniemulsion Technique for Application as New Contrast Agent Materials

Nanocapsules containing the hydrophilic contrast agents Magnevist® and Gadovist® are synthesized in an inverse miniemulsion process. First, nanodroplets of 100 to 550 nm are formed which are subsequently encapsulated by an interfacial polyaddition in polymeric shells of polyurethane, polyurea and crosslinked dextran. The shell thickness can be adjusted by the monomer concentration. Due to the porosity of the polymeric shell, exchange of water molecules through the capsule wall can be ensured and no significant compromises in the T 1 relaxitivity of the contrast compound is observed for magnetic resonance imaging (MRI). This clearly indicates the potential use of the contrast agent filled nanocapsules as new MRI contrast agents.