Research

Our research interests focus on the development and evaluation of radiolabeled agents for imaging and diagnosis. The breadth of the research include the development of techniques for production of radionuclides utilizing biomedical cyclotrons. For example, targetry has been developed to produce ⁶⁴Cu by the nickel and ⁶⁴NI (p,n) ⁶⁴Cu nuclear reaction.

Inorganic Radiopharmaceuticals. Studies have been carried out to develop radiopharmaceuticals labeled with inorganic radionuclides including ⁶⁴Cu. The thiosemicarbazones Cu-ATSM and Cu PTSM differ in one electron reduction potential by 89 mV. Cu-PTSM is trapped in all tissues and measures blood flow, while Cu-ATSM is only trapped in hypoxic tissue and so can quantify tissue in hypoxia. It is being used in patient studies evaluating hypoxia in the brain, heart and tumors.

Organic Radiopharmaceuticals. We have had a long time collaboration with Professor John A. Katzenellenbogen of the Department of Chemistry at the University of Illinois and the development of radiolabeled steroids for imaging steroid hormone receptors. These include agents for the estrogen and androgen receptors. FDHT, a ligand for the androgen receptor, has been used to image the blocking of androgen receptor after treatment with the anti-androgen flutamide. This study can be utilized to determine early in the course of treatment the ultimate efficacy of the therapy.

Selected Publications

• X. Sun, M. Wuest, Z. Kovacs, A.D. Sherry, R. Motekaitis, Z. Wang, A.E. Martell, M.J. Welch, and C.J. Anderson, "In vivo behavior of copper-64-labeled methanephosphate tetraazamacrocyclic ligands," J. Biol. Inorg. Chem., 8, 217 (2003).
• R.L. Aft, J.S. Lewis, F. Zhang, J-Y Kim, and M.J. Welch, "Enhancing targeted radiotherapy by 64Cu-ATSM using 2-Deoxy-D-Glucose," Cancer Research, 63, 5496 (2003).
• J. Yoo, D.E. Reichert, and M.J. Welch, "Regioselective N-substitution of cyclen with two different alkyl groups: Synthesis of all possible isomers," Chem. Comm.,6, 766 (2003).
• L.G. Luyt, H.M. Bigott, M.J. Welch, and J.A. Katzenellenbogen, "7a and 17a-substituted estrogens containing tridentate tricarbonyl rhenium/technetium complexes: Synthesis of estrogen receptor imaging agents and evaluation using microPET with technetium-94m," Bioorganic & Medicinal Chemistry, 11, 4977 (2003).