Controlled chemical derivatisation of carbon nanotubes with imaging, targeting, and therapeutic capabilities

In the context of drug delivery, carbon nanotubes (CNTs) hold a great potential as carrier thanks to their capacity 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 targeting ligand, and fluorescein. 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 maneuver the types of functionalities required on the nanotubes for a multimodal therapeutic strategy.