Nanotechnology for the Environment and Medicine.

Nanotechnology encompasses the production and applications of physical, chemical, and biological systems at scales ranging from individual atoms or molecules to around 100 nanometres, as well as the integration of the resulting nanostructures into larger systems. Nanomaterials differ from bulk materials for their relatively larger surface-area-to-mass ratio, consequently they become more chemically reactive and can show different optical, magnetic and electrical behaviours. In recent years, engineered nanomaterials have gained a particular attention in some fields such as environmental protection (soil, air and water remediation/treatment) and medicine (bio-sensing, imaging, and drug delivery). Nanoparticles can be used to monitor in real-time some pollutants (including heavy metal ions, organic compounds, microbiological pathogens, etc.) present even at extremely low concentrations in different environments. The use of nanomaterials for waste remediation/treatment results in a technology more cost-effective and rapid than current conventional approaches thanks to their enhanced surface area, transport properties, and sequestration characteristics. In addition, the integration of molecular biology and medicine with nanotechnology has resulted in new active nanostructures able to interact with biological systems. Nanocarriers based on carbon nanotubes, fumed silica (SiO2), titanium dioxide (TiO2), and magnetite and maghemite (Fe3O4, and γ-Fe2O3) nanoparticles have a distinct advantage over other drug carriers as they can be opportunely designed to reach the desired targets. As a consequence, such nanostructures can represent an important platform for enhanced medical imaging and controlled drug delivery. Here, some applications of nanomaterials as water purifying agents and drug delivery systems are reported.