Three novel agents, AF750-G-pip-Sta-BBN (1), AF750-GSG-Sta-BBN (2), and AF750-6Ahx-Sta-BBN (3), exhibited an excellent binding-specificity and affinity to human PC-3 prostate cancer cells in vitro, and a remarkable in vivo tumor-selectivity and NIRF imaging sensitivity in PC-3 tumor-bearing mice.
Fluorescence microscopy and in vitro cellular MRI demonstrated GRP receptor-specific and enhanced cellular uptake of the Gd<sub>2</sub>O<sub>3</sub>-FI-PEG-BBN in PC-3 tumor cells.
The new (99m)Tc-labeled biomolecule was stable in vitro, showed high affinity for the human GRP receptor expressed in PC3 cells and the rate of internalization was found to be time-dependent tissue distribution of the radiopeptide was evaluated in normal mice and in prostate cancer experimental models and significant radioactivity uptake was observed in the pancreas of normal mice as well as in PC3 tumors.