Intranasal Radioiodinated Ferulic Acid Polymeric Micelles as the First Nuclear Medicine Imaging Probe for ETRA Brain Receptor.

Abstract

Introduction: The aim of this work was to prepare a selective nuclear medicine imaging probe for the Endothelin 1 receptor A in the brain.

Material and methods: Ferulic acid (an ETRA antagonist) was radiolabeled using ¹³¹I by direct electrophilic substitution method. The radiolabeled ferulic acid was formulated as polymeric micelles to allow intranasal brain delivery. Biodistribution was studied in Swiss albino mice by comparing brain uptake of ¹³¹I-ferulic acid after IN administration of ¹³¹I-ferulic acid polymeric micelles, IN administration of ¹³¹I-ferulic acid solution and IV administration of ¹³¹I-ferulic acid solution.

Results: Successful radiolabeling was achieved with an RCY of 98 % using 200 μg of ferulic acid and 60 μg of CAT as oxidizing agents at pH 6, room temperature and 30 min reaction time. ¹³¹I-ferulic acid polymeric micelles were successfully formulated with the particle size of 21.63 nm and polydispersity index of 0.168. Radioactivity uptake in the brain and brain/blood uptake ratio for I.N ¹³¹I-ferulic acid polymeric micelles were greater than the two other routes at all periods.

Conclusion: Our results provide ¹³¹I-ferulic acid polymeric micelles as a hopeful nuclear medicine tracer for ETRA brain receptor.