Freddy Nguyen, an M.D./Ph.D. student in Professor Stephen Boppart’s Biophotonics Imaging Laboratory, was awarded an FY07 BCRP Predoctoral Traineeship Award to optimize the use of an innovative imaging technology, magnetomotive optical coherence tomography (MM-OCT), which can provide real-time microscopic analysis of tumor cells. Specifically, Mr. Nguyen’s project is to develop and optimize protein microspheres as a multimodal contrast agent to be used in conjunction with MM-OCT. Mr. Nguyen has focused on encapsulating iron oxide nanoparticles and fluorescent dyes into the inner cores of modified protein microspheres capable of specifically targeting tumor neovessels, which are the blood vessels that tumors form to support their rapid growth. Tumor neovessel specificity was achieved by coating the microspheres with an arginine-glycine-asparatate (RGD) peptide, which binds to the αvβ3 integrin receptor on the surface of tumor neovessel endothelial cells. Preliminary studies confirmed that the microspheres preferentially bind to the tumor cells because they overexpress αvβ3 integrins in vitro. The microspheres accumulated in the neoves- sels at the tumor sites when injected into tumor-bearing rats. Mr. Nguyen plans to further pur- sue the cancer-specific targeting of the protein microspheres as a potential diagnostic contrast agent as well as a therapeutic agent in the treatment of breast cancer.