Nanostructures between natural environment and medical practice

Nanoparticles (NPs) are small structures under 100 nm in dimension. Interrelationships among the mor- phological parameters and toxicity of NPs have been the focus of several investigations that assessed potential health risk in environmentally-exposed subjects and the realistic uses of NPs in medical practice. In the current review, we provide a summary of the cellular mecha- nisms of membrane-mediated transport, including old and novel molecules that transport nanostructures across cellular membranes. The effects of geochemical exposure to natural NPs are evaluated through epide- miological data and cancerous pathways activated by Fe2+ NPs. Specifically, we discuss screening for papillary thyroid carcinomas in the inhabitants of the Sicilian vol- canic area surrounding Mount Etna to compare the inci- dence of thyroid carcinoma in this population. Lastly, considering the increased production of carbon nano- tubes (CNTs), we examine the toxicity and potential use of these engineered NPs in drug delivery of an extensive amount of therapeutic and imaging molecules (therano- sis) that can be conjugated to CNTs.