Novel Ferrocenyl Nitroxide Nanoparticles As Electron Paramagnetic Resonance Oximetry Probes in Vitro and in Vivo

Aims: In this article we report our recent developments in the field of electron paramagnetic resonance oximetry.

Materials & Methods: Novel synthesized ferrocenyl nitroxide radicals (FcN)-1-6 were evaluated to determine their electron paramagnetic resonance oxygen responsiveness and reduction resistance. The 3-ferrocenyl-N-(oxyl-2,2,6,6-tetramethylpiperidin-4-yl) butanamide radical (FcN-6), with outstanding electron paramagnetic resonance oxygen sensitivity, was encapsulated in Pluronic F-127 polymeric nanoparticles.

Results: The nanoparticles exhibited good oxygen sensitivity, long-term stability of responsiveness, targeting to lung, liver and tumor, and low toxicity.

Conclusion: These features make this novel nanoparticle especially valuable for mapping O₂ concentrations in the body and monitoring the oxygen level inside tissues.