Recent progress and perspectives on the toxicity of carbon nanotubes at organism, organ, cell, and biomacromolecule levels.

A wide application of carbon nanotubes (CNTs) is on the way owing to their unique structural, optical, mechanical and electronic properties, high specific surface area, and facile functionalization. As a result, human beings will inevitably be exposed to CNTs, especially when the tubes are utilized as diagnostic and therapeutic tools to better understand, detect, and treat human diseases. Therefore the new subject of nanotoxicology, which is the study of the toxicity of nanomaterials, is now gaining public concern. This review provides an overview and comments on recent advances (mostly within the last 3 years) in the toxicology of CNTs, including their toxicity targeted to cells, organs, tissues and the whole organism, including mammals and other species (e.g. aquatic species, plants, and bacteria). Not only these traditional subjects of toxicological study but the interaction of CNTs and biomacromolecules is also covered so that the mechanism of their toxicity may be understood and their undesirable properties are more likely to be avoided.