Maria Eugenia Fortes Brollo1, Patricia Hernandez Flores2, Lucía Gutiérrez3, Domingo F. Barber2, María del Puerto Morales1
1 Department of Energy, Environment and Health, Institute of Material Science of Madrid (ICMM-CSIC), Madrid, Spain
2 Department of Immunology and Oncology and Nanobiomedicine Initiative, Centro Nacional de Biotecnologıa, (CNB-CSIC), Madrid, Spain3 Department of Analytical Chemistry, Universidad de Zaragoza and CIBER-BBN, Instituto Universitario de Nanociencia de Aragon (INA), Zaragoza, Spain
Aggregation processes of magnetic nanoparticles in biosystems are responsible for alteration of their performance in vitro and in vivo due to the modification of their magnetic properties. Here we present a systematic study using different nanoparticle coatings, cell lines, subcellular localizations, and nanoparticle core sizes, in an attempt to isolate the source of the high variability of the results obtained from different studies on cellular magnetic hyperthermia. We have also developed models mimicking the aggregation degree and the spatial distribution of nanoparticles in biosystems (magnetoliposomes) and compare their magnetic properties with that of real biological examples (cells incubated with nanoparticles). The results indicate that the simple fact of being in contact with the cells makes the nanoparticles aggregate in a non-controlled way, which is not the same aggregation caused by the contact with the cell medium nor inside liposomes. These results could explain bibliographic data on the heating efficiency and MRI relaxivity changes for nanoparticles in contact with the cells.
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