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Nadja C. Bigall+, Sara Sánchez Paradinas+, Teresa Pellegrino++, Wolfgang J. Parak+
+ Fachbereich Physik, Philipps Universität Marburg, Marburg, Germany ++Fondazione Istituto Italiano di Technologia, Genoa, Italy Superparamagnetic iron oxide nanoparticles are interesting candidates for biomedical application such as hyperthermia treatment and magnetic resonance imaging MRI. For applications as MRI contrast enhancers it should be considered that the type of water transfer routes of the nanoparticles drastically influences the MRI signal, especially for the transversal relaxivities. 1Here, different water transfer routes for magnetic nanoparticles as well as their functionalization possibilities are discussed. Ligand exchange against polyethyleneimine ligands yields stable colloid.1 Alternatively, the nanoparticles can be embedded in an amphiphilic polymer2. Since this amphiphilic polymer expresses carboxylic groups on its surface, additional functional organic molecules can be attached after the solubilization, such as the methotrexate, which is a widely utilized drug for the cancer treatment. A different water transfer route includes the nanoparticles into lipid micelles which can further be functionalized for investigating metabolic processes in mice.3 The fourth route involves coprecipitation of magnetic nanoparticles and an amphiphilic polymer to yield superparamagnetic nanobeads with several nanoparticles assembled in the core and a polymer shell passivating these systems.4 Since the polymer utilized is of similar structure than the one for the encapsulation process, further functionalization can be performed, leading to nanoobjects with a variety of different functionalities such as cancer cell target specificity due to folic acid functionalization5 or the possibility to controlled adsorb or desorb multifold charged systems (like gold nanoparticles or silent interfering RNA) by changing the pH of the environment.6 The different nanosystems will be presented and their properties will be discussed in detail including characterizations with transmission electron microscopy, absorption and emission spectroscopy, dynamic light scattering and light microscopy. Information about the different transfer and assembly routes will be included. 1. Tromsdorf, U. I.; Bigall, N. C.; Kaul, M. G.; Bruns, O. T.; Nikolic, M. S.; Mollwitz, B.; Sperling, R. A.; Reimer, R.; Hohenberg, H.; Parak, W. J.; Forster, S.; Beisiegel, U.; Adam, G.; Weller, H. Nano Letters 2007, 7, (8), 2422-2427. 2. Pellegrino, T.; Manna, L.; Kudera, S.; Liedl, T.; Koktysh, D.; Rogach, A. L.; Keller, S.; Radler, J.; Natile, G.; Parak, W. J. Nano Letters 2004, 4, (4), 703-707. 3. Bruns, O. T.; Ittrich, H.; Peldschus, K.; Kaul, M. G.; Tromsdorf, U. I.; Lauterwasser, J.; Nikolic, M. S.; Mollwitz, B.; Merkell, M.; Bigall, N. C.; Sapra, S.; Reimer, R.; Hohenberg, H.; Weller, H.; Eychmueller, A.; Adam, G.; Beisiegel, U.; Heeren, J. Nature Nanotechnology 2009, 4, (3), 193-201. 4. Di Corato, R.; Piacenza, P.; Musaro, M.; Buonsanti, R.; Cozzoli, P. D.; Zambianchi, M.; Barbarella, G.; Cingolani, R.; Manna, L.; Pellegrino, T. Macromolecular Bioscience 2009, 9, (10), 952-958. 5. Di Corato, R.; Bigall, N. C.; Ragusa, A.; Dorfs, D.; Genovese, A.; Marotta, R.; Manna, L.; Pellegrino, T. Acs Nano 2011, 5, (2), 1109-1121. 6. Bigall, N. C.; Curcio, A.; Leal, M. P.; Falqui, A.; Palumberi, D.; Di Corato, R.; Albanesi, E.; Cingolani, R.; Pellegrino, T. Advanced Materials 23, (47), 5645-+. |
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