Characterisation of magnetic nanoparticles for their potential application in Magnetic Particle Imaging

Abstract

Event Abstract Back to Event Characterisation of magnetic nanoparticles for their potential application in Magnetic Particle Imaging Dietmar Eberbeck1*, Frank Wiekhorst1, Peter Zirpel1 and Lutz Trahms1 1 Physikalisch-Technische Bundesanstalt, Germany Recently, Magnetic Particle Imaging (MPI), a quantitative method for imaging a magnetic nanoparticle (MNP) distribution in tissue, has developed to a topic of intense research. In order to achieve high sensitivity the magnetite particle cores of the MNP need to be nearly monodisperse in size about 40 nm and should have a magnetic anisotropy as small as possible. We compare Resovist, the MNP-system prevalently used for MPI experiments so far, with SHP-20 (Ocean NanoTec), a system with significantly larger MNP cores. As determined by TEM, Resovist/SHP-20 has a mean core diameter of about 5 nm/20 nm and a width of the size distribution of about 30%/10%. We employed magnetorelaxometry (MRX) and magnetisation measurements (M(H)) to analyse the size distribution of the magnetic moments and the anisotropy constant. For Resovist the M(H) data reveal the presence of a bimodal size distribution with peaks at 5 nm and 23 nm diameter. We attribute these values to single core particles and MNP aggregates. The presence of MNP aggregates is confirmed by MRX and, independently by PCS and SAXS. From MRX measurements on immobilised Resovist MNP we estimate an effective anisotropy constant of 5 kJ/m3. For SHP-20 the magnetisation data affirm the mean size of 20 nm and a slightly broader size distribution of 14% compared to TEM data. MRX data yield a higher anisotropy constant of 20 kJ/m3. Finally, based on the measured M(H) curves we calculated the normalized harmonic MPI response spectrum for a sinoidal excitation of 10 mT for both MNP systems. Regarding the single core size distributions, SHP-20 MNP should exhibit a much higher MPI signal strength (about 2 orders of magnitude) than Resovist. Here, we found nearly equal signal strengths, which we attribute to the clusters in Resovist contributing essentially to the signal. This shows the importance to accurately specify the degree of aggregation of a MNP system, to allow for its influence and deviations in magnetic behavior. Conference: Biomag 2010 - 17th International Conference on Biomagnetism , Dubrovnik, Croatia, 28 Mar - 1 Apr, 2010. Presentation Type: Poster Presentation Topic: Nanoparticles, Biosusceptometry and Effects of Magnetic Fields Citation: Eberbeck D, Wiekhorst F, Zirpel P and Trahms L (2010). Characterisation of magnetic nanoparticles for their potential application in Magnetic Particle Imaging. Front. Neurosci. Conference Abstract: Biomag 2010 - 17th International Conference on Biomagnetism . doi: 10.3389/conf.fnins.2010.06.00398 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 08 Apr 2010; Published Online: 08 Apr 2010. * Correspondence: Dietmar Eberbeck, Physikalisch-Technische Bundesanstalt, Berlin, Germany, dietmar.eberbeck@ptb.de Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Dietmar Eberbeck Frank Wiekhorst Peter Zirpel Lutz Trahms Google Dietmar Eberbeck Frank Wiekhorst Peter Zirpel Lutz Trahms Google Scholar Dietmar Eberbeck Frank Wiekhorst Peter Zirpel Lutz Trahms PubMed Dietmar Eberbeck Frank Wiekhorst Peter Zirpel Lutz Trahms Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.