Preparation of 64Cu-NODAGA-RGD-BBN labeled compound and its absorbed dose estimation in humans based on mouse data

Calculating the absorbed dose in the human body is one of the first steps in radiopharmaceutical development. This study estimates the dose absorbed by humans from the novel identified compound of 64Cu-NODAGA-RGD-BBN. For this purpose, 64Cu-NODAGA-RGD-BBN labeled compound was first prepared by changing the labeling decisions in optimal conditions. The stability of labeled heterodimer peptide was evaluated in phosphate-buffered saline (PBS) and human blood serum for 12 hours. After that, the complex's bio-distribution was investigated in tumor-bearing mice for 12 hours after injection. Finally, the dose absorbed by humans after injection of the 64Cu-NODAGA-RGD-BBN labeled compound was calculated based on mouse data using RADAR and mass extrapolation methods. The results showed that the obtained labeled compound could be produced with a high radiochemical purity of more than 99% and is highly stable (higher than 96%). 64Cu-NODAGA-RGD-BBN showed high uptake in gastrin-releasing peptide receptor-expressing tumors compared to other non-target organs. Furthermore, the dose assessment for this compound indicated that the body and other organs did not absorb a significant dose after injection.