Synthesis and Evaluation of 125I-IMPY: Application in Neuroblastoma Tracing and Treatment

Life (Basel). 2025 Jun 9;15(6):930. doi: 10.3390/life15060930.

Abstract

Background: Radiolabeled compounds can serve as diagnostic or therapeutic agents depending on the characteristics of the isotopes used. IMPY (6-iodo-2-(4'-dimethylamino)-phenyl-imidazo[1,2-a]pyridine) is a lipophilic derivative of thioflavin-T, designed to function as a tracer when labeled with radioactive iodine. While it has been primarily studied for imaging applications, its potential therapeutic effects when labeled with iodine-125 (125I) remain to be explored.

Methods: In this study, IMPY was synthesized and labeled with 125I for therapeutic purposes. Three different labeling methods were employed: isotope exchange reaction, redox reaction, and the Iodogen technique. The radiochemical yield of each method was determined to identify the most effective approach. Additionally, the effects of 125I-IMPY on neuroblastoma cells were evaluated by assessing its toxicity and cellular uptake.

Results: The radiochemical yields for the isotope exchange reaction, redox reaction, and Iodogen technique were found to be 0.96%, 10.74%, and 96.52%, respectively. The Iodogen technique exhibited the highest yield, exceeding 90% even after 48 h, making it the most efficient method. Furthermore, the impact of 125I-IMPY on neuroblastoma cells was analyzed, revealing significant cellular uptake and potential therapeutic effects.

Conclusions: This study demonstrated that the Iodogen technique is the most effective method for labeling IMPY with 125I. The high labeling efficiency and observed cellular effects suggest that 125I-IMPY could be considered not only as a tracer but also as a potential therapeutic agent for neuroblastoma. Further studies are needed to explore its full therapeutic potential and mechanism of action.

Keywords: IMPY; iodogen; isotope labeling; neuroblastoma; radioactive iodine.