High-aspect ratio nanoparticles in nanotoxicology.

In this Learned Discourse, we introduce nanotoxicology and note that little information is available on the role of aspect ratio in nanomaterial toxicity. Aspect ratio has implications for clearance from the lungs and for phagocytic cells such as the macrophage. Whether the role of aspect ratio on the nanoscale presents unique toxicological considerations remains unknown. In the case of rosette nanotubes, other physicochemical factors, such as solubility and the absence of metal content, might outweigh any possible effects incurred by aspect ratio. However, more systematic toxicity studies are required to determine the role of specific nanomaterial properties relative to biological responses.