Synthesis of 99mTc-labeled 2-Mercaptobenzimidazole as a novel radiotracer to diagnose tumor hypoxia.
Discovery of 99mTc-labeled imidazole derivatives as a potential radiotracer for hypoxic tumor imaging is considered to be of great interest because of non-invasive detection capabilities. 2-Mercaptobenzimidazole (2-MBI) was successfully synthesized, characterized and radiolabeled with [99mTc (CO)3(H2O)3]+ intermediate to form 99mTc-2-MBI complex with radiochemical purity of ≥95% yield as observed by instant-thin layer chromatography (ITLC) and radio-high performance liquid chromatography (radio-HPLC). The 99mTc-2-MBI complex was observed to be stable in saline and serum with no noticeable decomposition at room temperature and 37 °C, respectively, over a time period of 24 h. Biodistribution results in Balb/c mice bearing S180 tumor show that 99mTc-2-MBI highly internalized in tumor tissue, also possess preferably high tumor/muscle and tumor/blood ratios 4.14 ± 0.77 and 3.91 ± 0.63, respectively at 24 h incubation. Scintigraphic imaging study shows 99mTc-2-MBI is visibly accumulated in hypoxic tumor tissue, suggesting it would be a promising radiotracer for early stage diagnosis of tumor hypoxia.
['Rizvi|Syed Faheem Askari|SFA|', 'Zhang|Haixia|H|', 'Mehmood|Sajid|S|', 'Sanad|Mahmoud|M|']
Radiotracer Tumor hypoxia Imidazole S180 Tumor (99m)Tc-2-MBI Scintigraphy study