Comparison of Blood-Brain-Barrier Permeable Nitroxyl Contrast Agents for Magnetic Resonance Brain RedOx Imaging

Redox imaging technique is one of functional imaging method to visualize and estimate tissue redox status in living experimental animals, which can be achieved using magnetic resonance based imaging modalities, i.e. EPRI, OMRI and/or MRI. Nitroxyl radicals have been used as redox sensitive contrast agents. The redox imaging techniques can be applicable to brain by employing a blood-brain-barrier (BBB) permeable contrast agent. TEMPOL, which is one of most popular nitroxyl radical, is an amphiphilic molecule. Therefore, TEMPOL can easily permeate BBB and is highly redox sensitive, however; it has relatively high toxicity and shows quite fast in vivo decay. Several new nitroxyl radicals, which have lower toxicity, adequate in vivo decay rate, and good BBB permeability, have been developed for brain redox contrast agent. In this presentation, distributions and decay profiles of several different nitroxyl based contrast agents in a mouse brain were compared for optimizing brain redox imaging technique on MRI.SFRBM\u27s 19th Annual Meetin