Conjugation of functionalized gadolinium metallofullerenes with IL-13 peptides for targeting and imaging glial tumors

Background: Glioblastoma multiforme is the most common and most lethal primary brain tumor in humans, with median survival of approximately 1 year. Owing to the ability of glioma cells to aggressively infiltrate normal brain tissue and survive exposure to current adjuvant therapies, there is a great need for specific targeted nanoplatforms capable of delivering both therapeutic and imaging agents directly to invasive tumor cells. Method: Gadolinium-containing endohedral fullerenes, highly efficient contrast agents for MRI, were functionalized and conjugated with a tumor-specific peptide and assessed for their ability to bind to glioma cells in vitro. Results: We report the successful conjugation of the carboxyl functionalized metallofullerene Gd3N@C-80(OH)(similar to 26)(CH2CH2COOH)(similar to 16) to IL-13 peptides and the successful targeting ability towards brain tumor cells that overexpress the IL-13 receptor (IL-13R alpha 2). Conclusion: These studies demonstrate that IL-13 peptide-conjugated gadolinium metallofullerenes could serve as a platform to deliver imaging and therapeutic agents to tumor cells.