Nanoparticles: Uptake and Mechanism of Toxicity in the Body

Nanotechnology is an emerging multidisciplinary science that involves applications based upon the synthesis of molecules in the nanoscale (i.e., 10¿9 m) size range. The concept of ¿nanotechnology¿ is derived, in part, from the Greek word ¿nanö, meaning ¿dwarf¿. From a material sciences standpoint, the generation of new products using engineered nanomaterials is exciting because as one moves down the nanoscale, i.e, reducing the particle size range below ~100 nm), the properties of particles are known to change; and implementation of these properties can be exploited to provide products with enhanced applications. For example, gold particles can change colors to red or blue as the particle size is decreased within the nanoscale range. Moreover, pigment-grade titanium dioxide particles (generally in the 300¿400 nm size range), lose their white color and become colorless (i.e., transparent) at decreasing particle size ranges approaching 50 nm. This feature may be useful in the production of cosmetics (e.g., sunscreens) as well as other applications. Some particle-types which have been utilized for electrical insulating properties may become conductive at the nanoscale level.