US researchers have shown that carbon nanostructures can be coupled to antibodies and could find use in targeted cancer therapies.

Lon Wilson at Rice University, and colleagues, have taken the first step towards an immunotherapy system using fullerenes, nano-sized carbon spheres otherwise known as buckyballs.

In collaboration with a team led by Michael Rosenblum at the MD Anderson Cancer Center, Wilson coupled water soluble fullerenes to the antibody ZME-018. ZME-018 targets melanoma cells by binding to an antigen found on their surface. Wilson and Rosenblum found that their fullerene-antibody conjugate targeted cells containing the melanoma antigen almost as well as the free antibody.

What makes water-soluble fullerenes so attractive for therapeutics, said co-worker Jared Ashcroft, is their C₆₀ cage structure. The cage can be used to contain drugs until they reach the cancer cells. Wilson said his group have spent years learning to load (and retain) medically-interesting agents into carbon nanostructures and now they are ready to test them on cancer cells.

'If our entire family of carbon nanostructures can be targeted to cancer cells, a new field of cancer detection and treatment may follow,' said Wilson.

The researchers were particularly pleased to find that the attachment between ZME-018 and the fullerene did not involve a covalent bond. 'Because a covalent linkage is not needed for the antibody to interact with the fullerene', said Ashcroft, 'it provides a simpler method of preparing the fullerene drug.'

Janet Crombie