ABSTRACT
The pulmonary system is one of the main target organs of nanomaterials (NMs), especially for occupational exposures. The large surface area of the respiratory tract represents a huge surface of deposition and accumulation of airborne particles especially as the clearance mechanisms could be less efcient for particles at the nanoscale. The huge surface area of the respiratory system combined with inadequate clearance mechanisms may also allow nanoparticles (NPs) to pass the epithelial barrier leading to systemic exposures. It is of crucial importance to study not only the direct effect of NMs on resident lung cells but also their uptake and possible transcytosis and effects on the underlying cells and tissues. This capacity of NMs to pass through the epithelial barrier may also be benecial for nanomedical applications.1
