Emil T. Hofman Chair of Chemistry and Biochemistry and Director of the Integrated Imaging Facility at the University of Notre Dame
University of Notre Dame
Bradley Smith’s laboratory in Chemistry and Biochemistry is developing molecular probes for imaging and therapy. The researchers have developed novel fluorescent probes for in vitro and in vivo optical imaging. The probes are designed for maximum penetration of near-infrared light through tissue. Structurally the probes are composed of two components, a very bright organic fluorophore that is attached to a targeting ligand.
A major goal is to develop imaging methods that can measure the apoptotic index for cell and tissue samples ranging from biopsy to non-invasive in vivo imaging. The work aims to meet the need for rapid, post-treatment tests to see if anticancer therapies, including a wide variety of cancer chemotherapeutic agents, are inducing their intended apoptotic effect for any specific patient. This monitoring strategy is part of the growing field of personalized medicine.The researchers have discovered that small, synthetic zinc dipicolylamine coordination complexes have selective affinity for the surface of apoptotic cells. The probes can target the necrotic core of implanted human tumors (breast and prostate) in living mice and rats. The imaging signal increases when the animals are treated with targeted radiation or anticancer drugs.
A second project aims to develop new methods of treating cancer using photothermal therapy. In short, living subjects are dosed with molecular or nanoparticle probes that are designed to accumulate in tumors. The probes also contain a chromophore that absorbs 800 nm near-infrared light and creates a site of nanoscale heating that can be identified using high resolution, whole body imaging. Once a tumor has been located, a focused laser beam is employed to achieve localized hyperthermia and tumor ablation.