Vascular targeted single-walled carbon nanotubes for near-infrared light therapy ofcancer

Abstract

A new approach for targeting carbon nanotubes to the tumor vasculature was tested usinghuman endothelial cells and MCF-7 breast cancer cells in vitro. Single-walledcarbon nanotubes were functionalized with the F3 peptide using a polyethyleneglycol linker to target nucleolin, a protein found on the surface of endothelial cellsin the vasculature of solid tumors. Confocal microscopy and Raman analysisconfirmed that the conjugate was internalized by actively dividing endothelial cells.Dividing endothelial cells were used to mimic these cells in the tumor vasculature.Incubation with the conjugate for 8 h or more caused significant cell death in bothactively dividing endothelial cells and MCF-7 breast cancer cells, an effect that ishypothesized to be due to the massive uptake of the conjugate. This targeted cellkilling was further enhanced when coupled with near-infrared laser treatment. Forconfluent (non-dividing) endothelial cells, no cytotoxic effect was seen for incubationalone or incubation coupled with laser treatment. These results are promisingand warrant further studies using this conjugate for cancer treatment in vivo.