Radioiodination of Pimonidazole as a Novel Theranostic Hypoxia Probe.

BACKGROUND: Tumors are defined as abnormal tissue masses, and one of the most important factors leading to the growth of these abnormal tissue masses is Vascular Endothelial Growth Factor, which stimulates angiogenesis by releasing cells under hypoxic conditions. Hypoxia has a vital role in cancer therapy, thus it is important to monitor hypoxia. The hypoxia marker Pimonidazole (PIM) is a candidate biomarker of cancer aggressiveness. OBJECTIVE: It is aimed to radioiodinate PIM with Iodine-131 (131I) to join a theranostic approach. For this purpose, PIM was derivatived as PIM-TOS to be able to be radioiodinated. METHODS: PIM was derivated via a tosylation reaction. Derivatization product (PIM-TOS) was radioiodinated by using iodogen method and was analyzed by High Performance Liquid Chromatography and Liquid chromatography mass spectrometry. Thin layer radiochromatography was utilized for its quality control studies. RESULTS: PIM was derivatived successfully after the tosylation reaction. The radioiodination yield of PIM-TOS was achieved in yields of over 85 %. CONCLUSION: In the current study, radioiodination potential of PIM with 131I, as a potential theranostic hypoxia agent was investigated. Further experimental studies should be performed for developing a novel hypoxia probe including theranostics approaches.