The new scientific innovation of engineering nanoparticles (NPs) at the
atomic scale (diameter<100nm) has led to numerous novel and useful wide applications
in electronics, chemicals, environmental protection, medical imaging, disease
diagnoses, drug delivery, cancer treatment, gene therapy, etc. The manufacturers and
consumers of nanoparticle-related industrial products, however, are likely to be
exposed to these engineered nanomaterials, which have various physical and chemical
properties at levels far beyond ambient concentrations. These nanosized particles are
likely to increase unnecessary infinite toxicological effects on animals and the
environment, although their toxicological effects associated with human exposure are
still unknown. These ultrafine particles can enter the body through skin pores,
debilitated tissues, injection, olfactory, respiratory, and intestinal tracts. These uptake
routes of NPs may be intentional or unintentional. Their entry may lead to various
diversified adverse biological effects. Until a clearer picture emerges, the limited data
available suggest that caution must be exercised when potential exposures to NPs are
encountered. Some methods have been used to determine the portal routes of nanoscale
materials on experimental animals. They include pharyngeal instillation, injection,
inhalation, cell culture lines and gavage exposures.
Keywords: Intestinal tracts, NPs uptake, Respiratory system, Toxicological effects.
