Bimodal Probe for Magnetic Resonance Imaging and Photoacoustic Imaging Based on a PCTA-Derived Gadolinium(III) Complex and ZW800-1

One of the most widely used techniques to obtain anatomical information is magnetic resonance imaging (MRI). Despite its high resolution, it has a low sensitivity which could be enhanced by coupling MRI with a more sensitive technique such as photoacoustic imaging (PAI). The development of a bimodal agent could thus lead to hybrid images with a high anatomical resolution provided by MRI and a precise localization of the contrast agent thanks to PAI. The probes used in this work are a gadolinium(III) complex derived from PCTA-[12] for MRI and the ZW800-1 fluorophore for PAI. These two organic parts have been attached to a L-lysine derivative which has a third site for potential conjugation to a biovector, thus opening the field of targeted probes for molecular imaging. Preliminary relaxometric and photoacoustic characterizations indicate that this bimodal agent is a promising compound for bimodal imaging.