Novel superparamagnetic, luminescent nanoparticles for magnetic particle imaging (MPI) applications (SuLuMaP)

• Applicant: Professorin Dr. Esther Rösch
• Subject Area: Medical Physics, Biomedical Technology
• Term: from 2016 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 363034336

The aim of the research concept is to provide new bifunctional MPI tracer that combine superparamagnetic and luminescent properties, taking into account the most important factors such as quantum efficiency, biocompatibility, cell permeability, superparamagnetic and hydrodynamic radius, in order to increase the significance of multimodal diagnoses. The bifunctionality allows a complementary imaging approach. These tracers can be used for optical imaging to measure near-surface tracer distributions as two-dimensional projections with great spatial resolution at relatively low instrumental expense. Its use in MPI with substantially higher instrumental expense provides three-dimensional images of the tracer distribution in low-lying areas of the object of interest. Multimodal hybrid systems such as the recently introduced 3D dual-modal MPI-MRI system will be increasingly used in future. Recent research activities are concerned with cell tracking and describe the application of SPIO (superparamagnetic iron oxide nanoparticles) or 19F nanoemulsions, to perform multi-modal imaging using X-ray and MRI. In addition to luminescent lanthanide, also biocompatible organic dyes are going to be used. The hydrodynamic radius, which is responsible for the slowing of the relaxation, should be adjusted by means of the hydrophilic / hydrophobic surface property. For this purpose fluorinated compounds are being considered. There are four possibilities for the fluorination of the particles: 1) use of fluorinated polymers as coating for the magnetite 2) coupling of fluorinated organic dyes 3) use of fluorinated linkers with which the cell permeability can be enabled 4) end capping the free carboxyl - or silanol groups on the surface with fluorinated alkanes or dendrons. Due to these various options of fluorination of the particles, a fine adjustment of the surface polarity is possible which will be elaborated in systematic trials.

• DFG Programme: Research Grants