Encapsulation of a Radiolabeled Cluster Inside a Fullerene Cage, 177LuxLu(3−x)N@C80: An Interleukin-13-Conjugated Radiolabeled Metallofullerene Platform

In this communication, we describe the successful encapsulation of 177Lu into the endohedral metallofullerene 177LuxLu3−xN@C80 (x = 1−3) starting with 177LuCl3 in a modified quartz Kraschmer−Huffman electric generator. We demonstrate that the 177Lu (β-emitter) in this fullerene cage is not significantly released for a period of up to at least one-half-life (6.7 days). We also demonstrate that this agent can be conjugated with an interleukin-13 peptide that is designed to target an overexpressed receptor in glioblastoma multiforme tumors. This nanoparticle delivery platform provides flexibility for a wide range of radiotherapeutic and radiodiagnostic multimodal applications.