The Daily Bulletin

Please join the Chemistry and Physics departments for the seminar "Development of Transition Metal Complexes as MRI Contrast Agents," presented by Eric Snyder, Ph.D. candidate in chemistry at the University at Buffalo, on Thursday, May 4, at 12:30 p.m. in Science and Mathematics Complex 173. All students, staff, and faculty are welcome. This seminar is partially funded by Faculty-Student Association.

Abstract
Magnetic resonance imaging (MRI) is a molecular imaging modality that uses a magnetic field and a radiofrequency (RF) pulse to create images of the internal structure and soft tissues of the body. The signal in MRI is dependent on the relaxation of proton nuclear spins, predominately from bulk water in the body. While MRI produces high spatial resolution and soft tissue contrast, this modality lacks sensitivity, and thus contrast agents are administered to increase contrast on the MR image. Transition metal based contrast agents are of particular interest to provide patients with compromised kidney function alternatives to Gd(III) MRI contrast agents that are currently used in clinically approved contrast agent formulations today. Advantages of transition metal complexes include diverse coordination chemistry that permits tuning of the magnetic properties in response to changes in biological environment.

In the Morrow lab, we have developed MRI contrast agents based on two classes of MRI agents: chemical exchange saturation transfer (CEST) and T1 relaxivity agents. Our CEST agents use HS Co(II) and HS Fe(II) transition metal ions that produce sharp, highly shifted water proton resonances. T1 relaxivity agents require complexes that possess high magnetic susceptibility, fast water exchange rates, and slow electronic relaxation times, and thus we chose to use the HS Fe(III) ion. Our complexes use macrocyclic ligands for control of spin state and oxidation state with both the macrocycle backbone and pendent groups being important for controlling the coordination chemistry. In vitro and in vivo imaging data is obtained on a 4.7T MRI scanner through collaboration with Roswell Park Cancer Institute.