Designer Magnetic Disk Particles for Magnetic Particle Imaging and Hyperthermia

• Applicant: Professor Dr.-Ing. Matthias Gräser
• Subject Area: Measurement Systems ; Medical Physics, Biomedical Technology
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 572231021

Early detection and visualization of tumor shape for guided surgical interventions or localized therapies are essential for a successful treatment outcome. Magnetic particle imaging (MPI) is a relatively new, background-free imaging modality with remarkable potential, including functional imaging with high spatial and temporal resolution. However, the currently widely used chemically synthesized magnetic particles not only limit MPI performance, but also limit the success of nanoparticle-based hyperthermia treatments for tumors. We will produce magnetic disk particles (MDPs) with performance-optimized properties by using a fabrication route that allows free choice of material and composition as well as precise control of particle geometry and architecture. In particular, we will rely on sputter deposition of magnetic multilayer systems and structure them into MDPs that can be detached from the substrate and biochemically functionalized. Drawing on our expertise in biochemical particle functionalization and MPI, we will design, fabricate and functionalize MDPs to achieve performance limited only by the physics of the material systems. Our goal is to improve sensitivity and spatial resolution for MPI and localized hyperthermia (MHT) by an order of magnitude. This order of magnitude will result in better sensitivity and resolution in existing high gradient systems or a reduction in instrumentation requirements and therefore a reduction in cost. MPD systems with different magnetic switching properties will show a difference in magnetic response, which will improve the discrimination in multicontrast MPI. In addition to the improved MPI imaging properties, MDPs will also be designed to have much higher specific heat losses, enabling the treatment of smaller tumors or localized and temperature-controlled MPI-monitored hyperthermia applications. We aim to demonstrate this superior performance compared to existing magnetic nanoparticle tracers in initial proof-of-concept experiments for imaging and hyperthermia. Overall, the development and fabrication of such MDPs will represent a major leap in the performance of MPI contrast agents and enable evaluation of the technology required to scale up current MPI scanners to human size in the future. The MPD systems developed offer new avenues for 3D MPI imaging that can potentially be scaled up to human-sized objects. Furthermore, it opens up an increase in sensitivity and spatial resolution by orders of magnitude for localized, temperature-controlled hyperthermia tumor treatments.

• DFG Programme: Research Grants
• International Connection: Austria, Poland, Switzerland
• Partner Organisation: Fonds zur Förderung der wissenschaftlichen Forschung (FWF); Schweizerischer Nationalfonds (SNF)
• Cooperation Partners: Professorin Dr. Inge Herrmann; Professor Dr. Hans Josef Hug; Professor Dr. Michal Krupinski; Professor Dr. Dieter Suess