Intracellular distribution of magnetic nanoparticles and magnetic hyperthermia effects: a Focused Ion Beam study

Resumen del trabajo presentado a la 12th International Conference on the Scientific and Clinical Applications of Magnetic Carriers, celebrada en Copenhague (Dinamarca) del 22 al 26 de mayo de 2018.Magnetic hyperthermia (MHT) a strategy to achieve selective heating of target tissues is based on the use of magnetic nanoparticles (MNPs) as nano-heaters, through the coupling between an external alternating magnetic field (AMF) and the magnetic moment of the MNPs. Since the MNPs uploaded into the target cells are the heating source, their amount and final distribution within the intracellular space are two parameters of relevance in any physical model of cell death induced by MHT. Imaging analysis through electron microscopies has proven a potent tool for establishing the intracellular biodistribution. This work presents FIB-SEM a study on the intracellular distributions of different MNPs (Fe3O4, MnFe2O4 and CoFe2O4) within neuroblastoma and microglial cells before and after MHT. The MNP-loaded cells were seeded and fixed directly on coverslips, then were cross-sectioned by FIB, and analyzed by FIB-SEM in order to explore the final intracellular MNPs distribution. Embedding the MNP-loaded cells after the application of an ac magnetic field with an epoxy-resin allowed us to use the “slice and view” protocol to identify the changes on cell morphology and membrane integrity through 3D reconstruction.Peer Reviewe