LAUSR

Radiographic mapping of hypoxia is needed to study a wide range of diseases. Complexes of EuII are a promising class of molecules to fit this need, but they are generally limited by their rapid oxidation rates in vivo. Here, a perfluorocarbon-nanoemulsion perfused with N2 , forms an interface with aqueous layers to hinder oxidation of a new perfluorocarbon-soluble complex of EuII . Conversion of the perfluorocarbon solution of EuII into nanoemulsions results in observable differences between reduced and oxidized forms by MRI both in vitro and in vivo. Oxidation in vivo occurrs over a period of ∼30 min compared to <5 min for a comparable EuII -containing complex without nanoparticle interfaces. These results represent a critical step toward delivery of EuII -containing complexes in vivo for the study of hypoxia. This article is protected by copyright. All rights reserved.