Novel design of multimodal MRI/NIR optical contrast agent

We present a novel, dual modality gadolinium based MRI/near-infrared optical probe. Utilizing a fluorescent dye as a scaffold with attached Gd-chelating moiety, we demonstrated a substantial shortening of T1 relaxation time of water protons in vitro. The probe was compared to the commonly used MRI Gd-based contrast agents Magnevist® and Multihance® and showed superior contrast properties. The enhancement was due to strong albumin binding of the hydrophobic fluorophore and overall rigidification of the contrast agent. Due to the near-infrared optical properties of the probe and excellent MRI activity the proposed construct can be potentially utilized as a dual probe in multimodal MRI/NIR optical imaging.