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Photo of Kersin Witte

Kerstin Witte


to her website
 
Physics of New Materials, Rostock University
http://www.physik1.uni-rostock.de/user/agburkel/

Curriculum Vitae

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Her Topic of Materials' Days 2010:

Magnetic nanoparticles for biomedical applications


Abstract:
The development and application of modern magnetic materials requires a basic understanding of the magnetization processes that determine the magnetic properties. This can be obtained through preparation of novel magnetic systems, complex characterization methods and simulations. Nanostructured magnetic systems are playing a great role in material science nowadays because of the large range of possible applications. Magnetic nanoparticles commonly used in medicine are in the size range from several to hundreds of nanometers. The only possibility to see and be able to predict the behavior of a single particle is through micromagnetic simulations. Magnetic nanoparticles offer attractive possibilities as contrast agents because of the Nel relaxation. The particles show resonance behavior in a time - varying magnetic field. The MRI relies on the counterbalances between the small magnetic moment of a hydrogen proton and the extremely large number of hydrogen atoms in biological tissue. The presence of magnetic nanoparticles in biological tissue influences the relaxation times. The contrast enhancement due to the magnetic particles is related to the fact that we are shortening the relaxation time T2. Another attractive application is the magnetic cancer hyperthermia treatment. The potential of hyperthermia and thermal ablation in cancer therapy has been well noted. Temperatures between 42C and 46C lead to inactivation of norma l cellular processes, whereas above 46C, extensive necrosis occurs. The inability to d eposit effective doses of heat in a tumor without applying similar heat on surrounding tissues has prevented widespread clinical use. Magnetic nanoparticles responding to alternating magnetic fields provide a novel approach for the direct thermal ablation of tumor cells.