Radiolabeling of Zonisamide for a Diagnostic Perspective

Area of Science:

• Nuclear medicine
• Radiochemistry
• Neuroscience

Background:

• Epilepsy is a common neurological disorder lacking reliable biomarkers for tracking disease progression.
• Neuroimaging offers a non-invasive method to detect pathophysiological changes in epileptogenesis.
• Antiepileptic drugs (AEDs) are crucial for treatment, but their role in imaging epileptogenesis is underexplored.

Purpose of the Study:

• To investigate the radiolabeling potential of Zonisamide (ZNS), a second-generation AED, with Technetium-99m (99mTc).
• To develop a potential radiotracer for neuroimaging epileptogenic processes.
• To assess the diagnostic utility of radiolabeled ZNS in visualizing neurological conditions.

Main Methods:

• Zonisamide (ZNS) was successfully labeled with Technetium-99m (99mTc).
• Radiochemical yield of [99mTc]Tc-ZNS was quantified using Thin Layer Liquid Radio Chromatography (TLRC) and High Performance Liquid Radio Chromatography (HPLRC).
• In vitro studies evaluated the time-dependent uptake of [99mTc]Tc-ZNS in SHSY5Y human neuroblastoma cells.

Main Results:

• The radiolabeling process achieved a high radiochemical yield of 98.03 ± 1.24% for [99mTc]Tc-ZNS.
• [99mTc]Tc-ZNS exhibited significantly higher uptake in SHSY5Y cells compared to controls at 120 and 240 minutes (5.38 and 6.18 times, respectively).

Conclusions:

• The developed radiolabeled Zonisamide ([99mTc]Tc-ZNS) demonstrates promising diagnostic potential.
• This radiotracer can be utilized for imaging neurological processes, particularly in the context of epilepsy.
• The study contributes to the development of novel radiotracers for enhanced neuroimaging in neurological diseases.