European researchers have used carbon nanotubes to deliver an anticancer drug to human cancer cells.

Alberto Bianco at the Centre National de la Recherche Scientifique at Strasbourg, France, and colleagues in Italy and the UK investigated carbon nanotubes as potential carriers for small drugs. Bianco was following up the idea that nanotubes offer a unique opportunity for targeted drug delivery because they can penetrate cell membranes.

Bianco and colleagues attached molecules of both the anticancer drug methotrexate (MTX), and a fluorescent probe to multiwalled carbon nanotubes. The fluorescent probes allowed the team to monitor the uptake of the nanotubes in human cancer cells in vitro. They found that the fluorescent signal from the cells was proportional to the nanotube dose. 

Successful treatment of cancer relies on good bioavailability and delivery of an effective dose to the target organ, said Bianco. MTX is widely used against cancer but suffers from low cellular uptake, he added. The team are now studying the cytotoxicity of MTX connected to the modified nanotubes.

Bianco says that the next stage will be to modify the carbon nanotubes with a molecule that can selectively recognise a target, for example cancer cells. 'The challenge now is to demonstrate the real efficiency of the system using functionalised carbon nanotubes in an in vivo cancer model,' he said.

Janet F Crombie