Researchers have developed probes that use either gold nanorods or magnetic iron oxide nanoparticles, but Dr. Irudayaraj's nanoprobes use both, making them easier to track with different imaging devices as they move toward cancer cells. The magnetic iron oxide particles can be traced using magnetic resonance imaging (MRI), whereas the gold nanorods are luminescent and can be traced through microscopy, a more sensitive and precise process. Dr. Irudayaraj noted that an MRI is less precise than optical luminescence in tracking the probes but has the advantage of being able to track them deeper in tissue, expanding the probes’ possible applications. The gold nanorods act as the “string,” while the iron oxide nanoparticles, which are linked to the nanorods, serve as the “pearls.”
The probes contain the antibody herceptin, which is used in the treatment of metastatic breast cancer. Experiments demonstrated that these probes targeted and were taken up by cultured breast cancer cells expressing the Her-2 protein. The investigators also showed that the nanoprobes, when illuminated with near-infrared light, could serve as photothermal anticancer agents. The investigators are now working to add additional anticancer agents to these nanoscale constructs.