Nanoparticles (NPs) are included in a variety of consumer products including cosmetics, food, and food packaging. They are also used in medical products for dermal and oral application and for inhalation. The thinness of the air–blood barrier, the large absorption area of the lung, and the relatively low inactivation by enzymes provide fast entry to the systemic blood circulation at high drug concentrations. In addition to intended uptake, exposure to airborne particles from the environment and to NPs released during the manufacturing process may occur. Cytotoxicity is routinely studied for 4–48 h of exposure, but NPs may accumulate in cells and can cause cellular effects after longer times. Both extent and consequences of cellular NP accumulation are currently largely unknown.
Part of the book: Nanomaterials
Nanoparticles (NPs) are included in many products of daily life and present in the environment. Due to the potential of NPs to improve quality and stability of consumer and health and medical products, it is expected that the exposure of humans to engineered NPs will rather increase than decrease in the future. Although NPs did not act acutely cytotoxic on these concentrations, they may cause adverse effects upon chronic exposure. Cytotoxicity testing in long-term cultures and analysis of organelle function could identify such effects. Cells take up NPs mainly via active mechanisms, and these routes deliver their payload predominantly to lysosomes. Acute exposure of cells to NPs can have adverse effects on lysosome morphology and function, but lysosomes are also potential targets for accumulation. The chapter explains the role of lysosomes and describes techniques for labeling and assessment of their function. Examples for co-localization studies and vital dye staining are shown. A variety of techniques are available to characterize effects of NPs on lysosomes, but care has to be taken in the choice of the proper technique because NPs may interfere with the detection.
Part of the book: Lysosomes