Synthesis, characterization and application of superparamagnetic iron oxide nanoparticles in medical diagnostics and therapy: MR-visible implants for hernia repair and novel drug targeting models

In this dissertation, an integrated approach for the use of superparamagnetic nanoparticles (SPIO) in medicine is presented, starting from fundamental research on synthesis and characterization of SPIO nanoparticles and leading up to their clinical applications. In the first part, fundamental research on the synthesis of different SPIO samples by co-precipitation and thermal decomposition is described and key physical and chemical properties of SPIO are determined. For this, superconducting quantum interference magnetometry, dynamic laser scattering, transmission electron microscopy, atomic force microscopy, X-ray diffraction, magnetic resonance imaging and inductive heating were used. Based on the results of the synthesis and the physico-chemical characterization, the advantages and disadvantages of potentially useful types of SPIO for further application are described. In the second part, the physical characteristics and magnetic properties of co-precipitation SPIO nanoparticles are exploited to combine both diagnostic and therapeutic functionalities for two major medical applications as contrast agents and as drug carriers. The concept and realization of a mesh implant with incorporated SPIO nanoparticles for hernia repair that is visible in MRI is described. Furthermore, a new magnetic drug targeting approach for cancer therapies was developed based on FEM simulations. With optimized magnet geometries, an improvement of the calculated SPIO accumulation amount by a factor of 2 at the tumor site could be achieved. The results were qualitatively verified in in-vitro and in-vivo experiments.