Abstract Submitted to the ; NANOTUBE'05 Conference:

The ability of single walled carbon nanotubes (SWNTs) to act as molecular transporters that are able to cross the cellular membrane is reported. Covalent and non-covalent techniques are employed to yield SWNTs conjugates with a variety of proteins. It is observed that SWNTs are able to carry proteins (MW <80 kD) across the cellular membrane. Once released from the endosomal compartments, the functionality of the internalized cargo is assessed. We report that cytochrome-c transported inside cells via the SWNT transporter induces apoptosis, a cell death pathway. Cells that are exposed to the cytochrome-c itself (no SWNTs) do not exhibit any significant decline in cell viability. The cytoxocity of the SWNTs themselves is minimal, with cell viability and proliferation observed in cells exposed to SWNT conjugate being comparable to control, untreated cells. Current studies are underway to verify endocytosis as the internalization pathway in order to pinpoint the mechanism of entry as either through clathrin-coated pits or lipid rafts. SWNTs are emerging as a new class of molecular transporters for various biological cargos, with no apparent cytotoxic effects or disruption of the inherent biological functionality of the cargo after internalization. Exploiting the intrinsic physical properties of SWNTs in-vitro and the development of novel functionalization schemes to achieve selective internalization are also of interest and hold many promises for the application of SWNTs in drug delivery, protein delivery and gene therapy.