(540a) Biomimetic Properties of Carbon Nanotubes In Vivo

Multiwalled carbon nanotubes (MWCNTs) are well documented to invade the cytoplasm of eukaryotic cells and to interact with actin microfilaments and microtubules due to the many attributes they share with these cytoskeletal filaments. In particular, MWCNTs and microtubules have a similar length-to-with ratio and resiliency; they are both hollow cylinders; they both self-assemble, and form bundles to enhance their resistance. These features that provide MWCNTs with the intrinsic ability to interact with microtubules have also been suggested to lead, among others, to severe proliferative defects resulting in aneuploidy and cell death.

Our work demonstrates how MWCNTs display bio-mimetic interactions with microtubules at the molecular level assembling biosynthetic filaments in vivo. As a result of the different dynamical behavior of MWCNTs and microtubules, their interaction gives rise to the stabilization of the tubulin polymers. In fact, carbon nanotubes are exceptionally stable, while microtubules are highly dynamic polymers that are continuously undergoing assembly/disassembly cycles in vivo. Therefore, these interactions severely perturb microtubule dynamics, disorganizing the centrosomal microtubule pattern in the cell leading to aberrant mitotic spindle assemblies, chromosomal malsegregation between daughter cells, and often to mitotic catastrophe and cell death. Thus, our work gives an consistent explanation aneuploidy and mitotic failure in cells exposed to MWCNTs.