Zynaxis Cell Science, Inc. has developed fluorescent cell tracking molecules which bind cell membranes via a high affinity lipophilic linker without affecting viability, growth. Radionuclide-carrying analogs would allow clinical use of this novel technology with many cell types to follow migration of host cells to disease sites. Phase I specific aims are: i) synthesis of a cell tracking agent containing a covalently bound gamma emitter suitable for small animal whole body imaging (1231I-Zyn-1), and ii) characterization of its membrane binding stability and effects on erythrocyte and lymphocyte viability and function in vitro and erythrocyte lifetime in vivo. 131 I- Zyn-1 will have immediate commercial value for studies of cell trafficking in animal models of disease (cancer, thrombosis, atherosclerosis, arthritis, inflammation). Phase II will i) test the hypothesis that membrane bound radioimaging agent (131I-Zyn-1) are less toxic than current imaging agents which localize in the cytoplasm, and ii) develop analogs combining lipophilic linkers with chelators for nuclides used in clinical imaging (99m Tc, 111In, Gd). Cells labeled with the latter will be applicalb e to localization and disease monitoring of metastatic cancer, thrombosis, atherosclerosis, autoimmune lesions, and occult infection or bleeding.
