Cellular distribution and degradation of cobalt ferrite nanoparticles in Balb/3T3 mouse fibroblasts

The effect of the concentration of cobalt ferrite (CoFe2O4) nanoparticles (NPs) on their intracellular location and distribution has been explored by synchrotron radiation X-ray and fluorescence microscopy (SR-XRF) monitoring the evolution of NPs elemental composition as well. In cells exposed to low concentrations of CoFe2O4 NPs, the NPs preferentially segregate in the perinuclear region preserving their initial chemical content. At concentrations exceeding 500 mu M the XRF spectra indicate the presence of Co and Fe also in the nuclear region, accompanied by sensible changes in the cellular morphology. The increase of the Co/Fe ratio measured in the nuclear compartment indicates that above certain concentrations the CoFe2O4 NPs intracellular distribution could be accompanied by biodegradation resulting in Co accumulation in the nucleus. (C) 2011 Elsevier Ireland Ltd. All rights reserved.