Cellular uptake of nanoparticles as determined by particle properties, experimental conditions, and cell type

“The increased application of nanoparticles (NPs) is increasing the risk of their release into the environment. Although many
toxicity studies have been conducted, the environmental risk is difficult to estimate, because uptake mechanisms are often not determined
in toxicity studies. In the present Study, the authors review dominant uptake mechanisms of NPS in cells, as well as the effect of NP
properties, experimental conditions, and cell type on NP uptake. Knowledge of NP uptake is crucial for risk assessment and is essential to
predict the behavior of NPS based on their physical—chemical properties. Important uptake mechanisms for eukaryotic cells are
macropinocytosis. receptor—mediated endocytosis, and phagocytosis in specialized mammalian cells. The studies reviewed demonstrate
that uptake into nonphagocytic cells depends strongly on NP size, with an uptake optimum at an NP diameter of approximately 50 nm‚
Increasing surface charges, either positive 0r negative, have been shown to increase particle uptake in comparison with uncharged NPS.
Another important factor is the degree of (homo—) aggregation. Results regarding shape have been ambiguous. Difficulties in the
production of N Ps. with 1 property changed at a time. call for a full characterization of NP properties. Only then will it be possible to draw
conclusions as to which property affected the uptake.” © 2013 SETAC
(Citaat: Kettler, K., Veltman, K. et al. Cellular uptake of nanoparticles as determined by particle properties, experimental conditions, and cell type – Environmental Toxicology and Chemistry 33(2014)3, p.481-492)