Probes Pinpoint Tumors

Joseph Irudayaraj, associate professor of agricultural and biological engineering, designed the nanoscale, multifunctional probes, which have antibodies on board, to search out and attach to cancer cells.

"If we have a tumor, these probes should have the ability to latch on to it," Irudayaraj said. "The probe could carry drugs to target, treat as well as reveal cancer cells."

Scientists have developed probes that use gold nanorods or magnetic particles, but Irudayaraj's nanoprobes use both, making them easier to track with different imaging devices as they move toward cancer cells.

The magnetic particles can be traced through the use of an MRI machine, while the gold nanorods are luminescent and can be traced through microscopy, a more sensitive and precise process. Irudayaraj said 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 probes, which are about 1,000 times smaller than the diameter of a human hair, contain the antibody Herceptin, used in treatment of metastatic breast cancer. The probes would be injected into the body through a saline buffering fluid, and the Herceptin would find and attach to protein markers on the surface of cancer cells.

"When the cancer cell expresses a protein marker that is complementary to Herceptin, then it binds to that marker," Irudayaraj said. "We are advancing the technology to add other drugs that can be delivered by the probes."

Irudayaraj said better tracking of the nanoprobes could allow doctors to pinpoint the location of known tumors and better treat the cancer.

The novel probes were tested in cultured cancer cells. Irudayaraj said the next step would be to run a series of tests in mice models to determine the dose and stability of the probes.; Source: Purdue University