Some Thoughts About the Intracellular Location of Nanoparticles and the Resulting Consequences

It is qualitatively demonstrated that the intracellular localization of particles depends on the way they are administered, their basic physicochemical properties, as well as on incubation time. For this purpose cells were exposed to fluorescently-labelled particles of different size under different exposure scenarios including incubation, microinjection, electroporation, and sonoporation. After co-exposure to cells the intracellular distribution of different particles was imaged with multicolor fluorescence microscopy. Qualitative co-localization analysis demonstrates, that different particles to which cells have been exposed in different ways did not automatically reside in the same compartment. As intracellular particle localization may influence potential toxic effects of particles on cells, studies attempting to unravel molecular mechanisms of toxicity should involve the determination of the intracellular particle distribution.