Expanding the P2X7R toolbox: discovery of a novel Iodine-125 radioligand.

This Journal Club article reviews a 2025 study by Qiu et al. that reports the development of a novel iodine-125 radioligand targeting the purinergic P2X7 receptor (P2X7R). The researchers created a small library of structurally modified P2X7R antagonists and identified compound 1c as a lead due to its high affinity and selectivity. Radiolabeling with iodine-125 produced [I]1c with high yield and purity. Binding studies confirmed its strong nanomolar affinity, supporting its use in radioligand screening and potential applications in imaging P2X7R in inflammatory and neurodegenerative diseases. The study demonstrates the value of radiolabeled probes in drug discovery and purinergic signaling research.