These are based mainly on nitrogen-rich scaffolds, such as AMD070, and cyclic polyamines such as cyclam in the AMD3100 skeleton. Herein, we describe the synthesis of two novel CXCR4-directed radiopharmaceuticals, combining the AMD070 scaffold as a targeting unit, and bifunctional te1pa macrocycle as a strong 64Cu chelator. The synthesis of the conjugates and optimization of 64Cu-radiolabeling are presented, opening the way for future in vitro and in vivo studies.
Thank to their particular pharmacokinetics, the use of small organic molecules can be a very promising alternative to macromolecular targeting biomolecules (i.e. antibodies, peptides…) for specific imaging of tumours. Herein, the potential of two AMD070-like inhibitors as CXCR4-targeting units for specific imaging of cancer cells, and the influence of chromophore-grafting on their recognition properties has been investigated.
In conclusion, we compared different 177Lu-radiolabelled CXCR4-targeting peptides for their binding potential in GBM, and demonstrated their varied cytotoxic action against GBM cells in vitro, with POL3026 being the most promising, causing considerable DNA damage. Though the peptide's systemic biodistribution remains to be improved, our data demonstrate the potential of [177Lu]Lu-DOTA-POL3026 for CXCR4-TRT in the context of GBM.