The synthesis of a Tc-labeled tetravalent targeting probe upon isonitrile coordination to Tc for enhanced target uptake in saturable systems.

The presence of excess unlabeled ligands in the injectate hinders the target uptake of Tc-labeled targeting vectors. To address the issue, we previously developed a chemical design which provides a Tc-labeled trivalent RGD probe upon CN-βAla-Gly-Gly-c(RGDfK) (L) coordination to [Tc][Tc(CO)] core at pH 6.0.

Purification-Free Method for Preparing Technetium-99m-Labeled Multivalent Probes for Enhanced in Vivo Imaging of Saturable Systems.

Metallic radionuclides provide target-specific radiolabeled probes for molecular imaging in radiochemical yields sufficient for administration to subjects without purification. However, unlabeled ligands in the injectate can compete for targeted molecules with radiolabeled probes, which eventually necessitates postlabeling purification. Herein we describe a "1 to 3" design to circumvent the issue by taking advantage of inherent coordination properties of technetium-99m ((99m)Tc).