Synthesis and Evaluation of <sup>125</sup>I-IMPY: Application in Neuroblastoma Tracing and Treatment.

Abstract

<h4>Background</h4>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.<h4>Methods</h4>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.<h4>Results</h4>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.<h4>Conclusions</h4>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.