Controlled Chemical Derivatisation of Carbon Nanotubes with Imaging, Targeting, and Therapeutic Capabilities

In drug delivery, carbon nanotubes (CNTs) hold a great potential as carriers because of their ability to easily cross biological barriers and be internalised into cells. Their high aspect ratio allows multi-functionalisation and their development as a multimodal platform for targeted therapy. In this article, we report the controlled covalent derivatisation of triple-functionalised CNTs with the anticancer drug gemcitabine, folic acid as a targeting ligand and fluorescein as a probe. The anticancer activity of gemcitabine was maintained after covalent grafting onto the CNTs. The functionalised nanotubes were internalised into both folate-positive and negative cells, suggesting the passive diffusion of CNTs. Overall, our approach is versatile and offers a precise chemical control of the sidewall functionalisation of CNTs and the possibility to manoeuvre the types of functionalities required on the nanotubes for a multimodal therapeutic strategy.