Figure 1.

Uptake and intracellular fate of IONPs. Depending on IONP-size and coating and on the investigated cell type, different endocytic mechanisms contribute to the uptake of intact IONPs into the cells where the particles typically enter the endo-lysosomal system. Inside the cell, iron can be liberated from the NPs and contribute to several reactions including Fenton- and Haber-Weiss reactions leading to the formation of hydroxyl radicals which can induce cell damage.