Encapsulation of Tc-99m within fullerenes: A novel radionuclidic carrier

The nature of fullerenes as miniature 'isolation chambers' suggests the possibility of unstable atoms carried within the interior of the molecular cage forming endofullerenes which could isolate potentially reactive atoms from their environment. We have produced, characterized by various techniques including thin layer chromatography, and purified endofullerenes containing gamma-ray emitting Tc-99m, the first direct encapsulation of a radionuclide during fullerene formation. Identification of Tc-99m@C-60 and Tc-99m@C-70 has been accomplished by application of ultra-low level radiation detection methods. Appropriately derivatized, Tc-99m 'radioendofullerenes' could eventually be used as a radiopharmaceutical for medical imaging. (C) 1997 Published by Elsevier Science Ltd.