Multi-Dimensional Manipulation of Drug-Carrying Magnetic Nanobeads

B. Gleich, T. Weyh, M. Koch, C. Alexiou, R. Jurgons, and B. Wolf

Heinz Nixdorf-Chair for Medical Electronics, building N3, Technical University of Munich, Theresienst. 90, D-80333 Munich, Germany




In the biomedical field, suspensions of magnetic nanoparticles (ferrofluids) are used in both diagnostics (e.g. contrast medium in radiological imaging-techniques or specific cell-separation) and therapeutic areas, such as embolization of aneurysms with an external magnetic field. Ferrofluids can be covered with hydrophilic starch polymers coupled with endstanding functional groups (e.g. phosphate) allowing ionic binding to many therapeutic drugs. Specially functionalized magnetic nanoparticles can be used as biocompatible carriers for chemotherapeutical agents to improve locoregional concentrations. Appropriate magnetic fields can be calculated form the haemodynamics and the particle movement within the blood vessels. This external magnetic field with a well defined field gradient is able to move these particle-drug- complexes to the region of interest. Once the particle-drug-complexes reached the vessel wall the transfection through the vessel wall and the cell-membranes can be supported by time-dependant magnetic fields like revolving fields, wandering fields and pulse fields. This method enables the reduction of previously required drug doses (for e.g. successful tumor remission).