68Ga-labeled NODAGA-RGD-BBN heterodimer peptide as a novel radiotracer for dual integrin and GRPR-targeted tumor imaging

Background: due to the excellent physical and biochemical characteristics of 68ga, 68ga-1,4,7-triazacy–clononane–glutaric acid– 4,7 acetic acid- arginyl-glycyl-aspartic acid- bombesin (68ga-nodaga-rgd-bbn) was prepared as a new positron emission tomography (pet) imaging agent, and afterward, the preclinical evaluation of this labeled peptide was studied. materials and methods: 68ga radioisotope was extracted from a 68ge/68ga generator with high radionuclide, chemical and radiochemical purities. then; the 68ga-nodaga-rgd-bbn radiolabeled complex was prepared at optimized conditions. the stability of the complex was evaluated in phosphatebuffered saline (pbs) for at least 2 h. cell studies of the radiolabeled peptide were also assessed on the gastrin releasing peptide receptor (grpr)-expressing cell line. finally; the biodistribution and whole-body scan imaging study of 68ga-nodaga-rgd-bbn was studied in normal and tumor-bearing mice. results: the biodistribution and whole -body scan imaging of the radiolabeled compound on grpr-expressing tumor-bearing mice demonstrated the high uptake in the tumor site at all post-injection intervals. the biodistribution results also demonstrated the major excretion route of the complex is the urinary tract. conclusions: 68ga-nodaga-rgd-bbn shows high potential for pet imaging of patients with grpr-expressing tumors; however, more biological studies are still needed.