Pharmacokinetics of nanomaterials: an overview of carbon nanotubes, fullerenes and quantum dots.

A full understanding of the pharmacokinetic parameters describing nanomaterial disposition in the body would greatly facilitate development of a firm foundation upon which risk assessment could be based. This review focuses on the disposition of carbon based fullerenes and nanotubes, as well as quantum dots (QD) after parenteral administration to primarily rodents. The common theme across all particle types is that a major determinant of nanomaterial disposition is the degree of interaction with the reticuloendothelial (RE) cell system. Small water-soluble particles evading this system may be excreted by the kidney. Larger particles and those with the proper surface charge may get targeted to RE cells in the liver, spleen and other organs. Most nanomaterial kinetics are characterized by relatively short blood half-lives reflecting tissue extraction and not by clearance from the body. In fact, another common attribute to nanomaterial kinetics is retention of particles in the body. Finally, unlike many small organic drugs, nanomaterials may preferentially be trafficked in the body via the lymphatic system that has obvious immunological implications.