[Nano for better or worse: opportunities and risks with nanotechnology]

Engineered nanomaterials are produced for a wide range of applications, not least in medicine. Indeed, the field of nanomedicine is rapidly attaining maturity, with novel nanoscale constructs for diagnosis or therapy, or both (so-called theranostics). However, close attention should be paid to the potential environmental and human health impact of the emerging nanotechnologies. More information on human and environmental exposure is needed, along with a more detailed understanding of the hazard potential of different classes of nanomaterials. Animal studies have suggested that certain carbon nanotubes possess asbestos-like pathogenicity and IARC recently classified some but not all carbon nanotubes as potential carcinogens for humans. On the other hand, carbon nanotubes are also, under certain conditions, susceptible to enzymatic degradation by cells of the innate immune system, and this may serve to mitigate the (pulmonary) toxicity of such materials. Finally, recent research has served to shed light on the bio-corona of molecules adsorbed onto the surface of nanomaterials and its role in cellular uptake and cytotoxicity and for biodistribution in vivo.