Lanthanide DO3A‐Tropone Complexes: Efficient Dual MR/NIR Imaging Probes in Aqueous Medium

Abstract

In this work, we describe a novel DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) based ligand with a chromophoric tropone coordinating sidearm (1). Ln3+ complexes of 1 have one inner sphere water molecule. The r1 relaxivity of Gd1 is similar to that of the commercial Gd-based MRI agents. The neutral O-donor atom of the tropone moiety slows down the water exchange rate by a factor of 3 compared to GdDOTA. In addition, Nd1 and Yb1 complexes exhibit significant NIR emission in aqueous solutions indicating that the tropone unit is an efficient sensitizer for these Ln3+-ions. Therefore, this new ligand is a promising platform for the design of Ln3+ based dual MR/optical imaging probes.

Lanthanide conjugates as versatile instruments for therapy and diagnostics

“…1). 21,22 Recently, the high specificity in vivo targeting of tumour cells using a biotin-conjugated gadolinium(III)-DOTA (Gd(III)-DOTA) complex has been reported ( Fig. 2).…”

Luminescent Sensor Based on Ln(III) Ternary Complexes for NAD(P)H Detection

“…In this paper, we investigated the antenna effect for other Ln(III) ternary complexes usually emitting luminescence in the visible (Sm, Dy) and NIR region (Nd, Yb). In literature, some examples of binary Ln(III) complexes with ligands bearing antenna functional groups and emitting in the NIR region can be found [3,14,42,43]; therefore, photophysical studies for analogous ternary Ln(III) complexes are needed. In addition, the study of Nd(III) and Yb(III) ternary complexes is interesting from a structural point of view since the Nd(III) ion is the largest of the studied Ln(III) ions with a coordination number of 9.…”

A tumor-targetable probe based on europium(iii)/gadolinium(iii) complex-conjugated transferrin for dual-modal time-gated luminescence and magnetic resonance imaging of cancerous cellsin vitroandin vivo

“…21,22 In these mixed lanthanide systems, the concentration ratio of paramagnetic/luminescent species could be adjusted according to the sensitivity limit of OI and MRI. 23 In addition, luminescent lanthanide complexes exhibit unique advantages over other fluorescent materials, such as excellent spectral discrimination, no re-absorption effect, strong resistance to photobleaching and super-long luminescence lifetimes. 24 In particular, with the help of a time-gated luminescence (TGL) detection technique that introduces an appropriate delay time after excitation for collecting only the long-lived luminescence from the lanthanide complexes, luminescent lanthanide complexes enable background-free detection to be realized.…”