Labeling bombesin-like peptide with 99mTc via hydrazinonicotinamide: description of optimized radiolabeling conditions
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Bombesin (BNN)-like peptides have very high binding affinity for the gastrin-releasing peptide (GRP) receptor. The goal of the current study was to optimize the labeling conditions of a new 99mTc-radiolabeled BNN-like peptide based on the bifunctional chelating ligand HYNIC using different co-ligands (EDDA and tricine). The radiolabeling conditions (pH, amount of co-ligand, amount of stannous chloride, temperature and reaction time) for newly-formed 99mTc-tricine-HYNIC-Q-Litorin and 99mTc-EDDA-HYNIC-Q-Litorin were optimized and evaluated by RHPLC and RTLC. Radiochemical yields for 99mTc-tricine-HYNIC-Q-Litorin and 99mTc-EDDA-HYNIC-Q-Litorin were 98.0 ± 1.7 and 97.5 ± 2.5%, respectively. When EDDA was used as co-ligand, the labeling of 99mTc-EDDA-HYNIC-Q-Litorin was optimal in the following reaction mixture: HYNIC-peptide: EDDA: 10 μg/5 mg, pH 3, SnCl2 concentration: 12 μg/0.1 mL, reaction temperature: 100 °C, reaction time: 15 min. Besides, the optimum conditions were HYNIC-peptide:tricine: 10 μg/50 mg, pH 5, SnCl2 concentration: 12 μg/0.1 mL, reaction temperature: 100 °C, reaction time: 15 min for preparing 99mTc-tricine-HYNIC-Q-Litorin. The manufactured 99mTc-HYNIC-Q-Litorin conjugates may offer new possibilities for imaging cancer cells expressing bombesin receptors.
KeywordsHYNIC-BNN-like peptide Litorin Gastrin-releasing peptide 99mTc Co-ligand
The authors gratefully acknowledge the financial support received from the Scientific and Technological Research Council of Turkey, Scientific Project (TUBITAK Number 108S200).
- 4.Babich JW, Coco WG, Barrow S, Fischman AJ, Femia FJ, Zubieta J (2000) 99mTc-labeled chemotavtic peptides: influence of coligand on distribution of molecular species and infection imaging properties. Synthesis and structural characterization of model complexes with the Re(η2-HNNC5H4 N)(η1-NNC5H4N) core. Inorg Chim Acta 309:123–126CrossRefGoogle Scholar
- 22.Decristoforo C, Mather SJ (2002) The influence of chelator on the pharmacokinetics of 99mTc-labeled peptides. Q J Nucl Med 46:195–205Google Scholar