Background:In this study, [64Cu]Cu-NODAGA-RGD-BBN was prepared and its
preclinical assessments were evaluated for PET imaging of GRPR overexpressing tumors.Methods:NODAGA-RGD-BBN heterodimer peptide was successfully labeled with cyclotronproduced
copper-64 at optimized conditions. The radiochemical purity of the radiotracer was
checked by HPLC and RTLC methods. The stability of the radiolabeled compound was assessed
in PBS (4°C) and in human blood serum (37°C). Binding affinity and internalization of
[64Cu]Cu-NODAGA-RGD-BBN were studied on PC3, LNCaP, and CHO cell lines. The biodistribution
of the radiotracer was evaluated in normal and tumor-bearing mice.Results:[64Cu]Cu-NODAGA-RGD-BBN was prepared with radiochemical purity >99 ± 0.7%
(HPLC/ITLC) and specific activity of 18.5 ± 2.2 TBq/mmol. The radiotracer showed high stability
in PBS (95 ± 1.05%) and in human blood serum (96 ± 1.24%) and, high affinity to the
GRP expressing tumor cells. [64Cu]Cu-NODAGA-RGD-BBN showed hydrophilic (log p =
-1.14) and agonistic nature. The biodistribution and imaging studies demonstrated high uptake
at the tumor site at all intervals post-injection and 3-4 h post-injection can be considered an appropriate
time of imaging.Conclusion:The results indicated that [64Cu]Cu-NODAGA-RGD-BBN radiolabeled heterodimer
peptide can be considered as a high-potential agent for PET imaging of GRPRoverexpressing
tumors.
