Evaluation of EuII-based positive contrast enhancement after intravenous, intraperitoneal, and subcutaneous injections

Abstract

EuII-based contrast agents offer physiologically relevant, metal-based redox sensing that is unachievable with GdIII-based contrast agents. To evaluate the in vivo contrast enhancement of EuII as a function of injection type, we performed intravenous, intraperitoneal, and subcutaneous injections in mice. Our data reveal a correlation between reported oxygen content and expected rates of diffusion with the persistence of EuII-based contrast enhancement. Biodistribution studies revealed europium clearance through the liver and kidneys for intravenous and intraperitoneal injections, but no contrast enhancement was observed in organs associated with clearance. These data represent a step toward understanding the behavior of EuII-based complexes in vivo. Copyright © 2016 John Wiley & Sons, Ltd.