Dual modal imaging agents based on chromophore-bearing DTPA analogues

Abstract

Two new DTPA analogues, centrally (L¹) and terminally (L²) functionalised with a 1,8-naphthalimide chromophore, have been successfully prepared and fully characterized. Their Gd(III) complexes have also been prepared and evaluated for their ability to act as dual modal contrast agents (MRI/OI). The highly reproducible R₁ relaxivity of L¹ (8.10 ± 0.21 mM⁻¹ s⁻¹, 25 °C and 30 MHz) is markedly higher than other DTPA based contrast agents. The Gd(III) complexes of both L¹ and L² have been evaluated as luminescence probes; the ligand based fluorescence is not quenched upon complexation.