[68Ga]Ga-DFO-c(RGDyK): Synthesis and Evaluation of Its Potential for Tumor Imaging in Mice

Angiogenesis has a pivotal role in tumor growth and the metastatic process. Molecular imaging was shown to be useful for imaging of tumor-induced angiogenesis. A great variety of radiolabeled peptides have been developed to target alpha v beta 3 integrin, a target structure involved in the tumor-induced angiogenic process. The presented study aimed to synthesize deferoxamine (DFO)-based c(RGD) peptide conjugate for radiolabeling with gallium-68 and perform its basic preclinical characterization including testing of its tumor-imaging potential. DFO-c(RGDyK) was labeled with gallium-68 with high radiochemical purity. In vitro characterization including stability, partition coefficient, protein binding determination, tumor cell uptake assays, and ex vivo biodistribution as well as PET/CT imaging was performed. [Ga-68]Ga-DFO-c(RGDyK) showed hydrophilic properties, high stability in PBS and human serum, and specific uptake in U-87 MG and M21 tumor cell lines in vitro and in vivo. We have shown here that [Ga-68]Ga-DFO-c(RGDyK) can be used for alpha v beta 3 integrin targeting, allowing imaging of tumor-induced angiogenesis by positron emission tomography.

Automated summary

The study synthesized DFO-c(RGD) peptide conjugate for radiolabeling with gallium-68 and demonstrated its high stability and tumor-targeting properties. The radiolabeled peptide showed hydrophilic properties, high stability, and specific uptake in tumor cell lines both in vitro and in vivo, making it a promising tool for imaging tumor-induced angiogenesis by positron emission tomography.