Hazard and risk associated with the use and development of metal Nanoparticles

Nanoparticles (NPs) present novel properties, when compared to conventional materials due to their tiny dimension. In fact at the nanoscale level, which goes between 1 and 100 nm, the materials demonstrate properties different from the bulk, with all the associated chemical and physical properties. These properties are unique and constitute the basis for the plethora of potential applications including a biomedical perspective. But at the same time the NPs and in particular metal-NPs, can also give rise to unexpected and hazardous toxicities [1-4]. In engineered metal-NPs, the potentially harmful effects may originate not only from their chemical composition but also from their small nature and the high reactivity. The reduced size of NPs increases the number of surface molecules and their surface area exponentially, leading to complex biophysicochemical interactions and enables the NPs to bypass the biological barriers, thus allowing deep tissue penetration and their consequent accumulation in a number of organs where them can cause cytotoxic outcomes. The increasing use of NPs today therefore warrants a careful assessment of the possible negative effects associated with these particles. Time and effort should be spent on investigating the possible impact of these NPs in order to allow them to be used in a safe and well-controlled manner for the benefit of mankind. The ability to forecast and avoid potential human and environmental problems across the life cycle of NPs development, including use and disposal, is strongly required to achieve a sustainable development of nanotechnology.