Fibrillous carbon nanotube: an unexpected journey.

The emergence of nanomedicine, a discipline at the nexus of materials engineering, chemistry, biology, and pharmacology, has generated much excitement in the field of translational medical research and provided some unexpected results. Nanomedicine seeks to introduce nanoscale technology to the practice of medicine via the design and development of nanomaterials possessing therapeutic or diagnostic functions. However, as expected, any modification of the base nanomaterial platform to decorate it with solublizing, targeting, therapeutic, or diagnostic modalities yields a material with a very different pharmacological profile than the original platform. Clearly, the goal of nanotechnology is to put into practice a novel synthetic substance in which the function of the complex is greater than the sum of its components. These new compositions must be thoroughly evaluated in vivo. Therefore, reliance on pharmacokinetic predictions based solely on the baseline profile of the original platform can confuse the field and delay progress. Carbon nanotube pharmacokinetic profiles provide an interesting example of this situation. Covalently functionalized nanotubes exhibit fibrillar pharmacology while those nanotubes that are not covalently functionalized transiently behave as fibers and then tend toward an overall colloidal profile in vivo.