A Class of Fe^III Macrocyclic Complexes with Alcohol Donor Groups as Effective T₁ MRI Contrast Agents.

ABSTRACT: Early studies suggested that Fe^III complexes cannot compete with Gd^III complexes as T₁ MRI contrast agents. Now it is shown that one member of a class of high-spin macrocyclic Fe^III complexes produces more intense contrast in mice kidneys and liver at 30 minutes post-injection than does a commercially used Gd^III agent and also produces similar T₁ relaxivity in serum phantoms at 4.7 T and 37 °C. Comparison of four different Fe^III macrocyclic complexes elucidates the factors that contribute to relaxivity in vivo including solution speciation. Variable-temperature ¹⁷ O NMR studies suggest that none of the complexes has a single, integral inner-sphere water that exchanges rapidly on the NMR timescale. MRI s

SUBMITTER: Snyder EM 

PROVIDER: S-EPMC7502272 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature