Test aims to detect tumors with tiny, light-up tubes

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Researchers have refined and, for the first time, run in vivo tests of a method that may allow nanotube-based probes to locate specific tumors in the body.

The new results suggest that antibody-nanotube probes could potentially detect tumors with as few as 100 ovarian cancer cells…

Their ability to pinpoint tumors with submillimeter accuracy could eventually improve early detection and treatment of ovarian cancer.

The noninvasive technique relies on single-walled carbon nanotubes that researchers can optically trigger to emit shortwave infrared light. The lab of chemist Bruce Weisman, a pioneer in the discovery and interpretation of the phenomenon, reports the new results in ACS Applied Materials and Interfaces.

For this study, the researchers used the technique to pinpoint small concentrations of nanotubes inside rodents.

The lab of coauthor Robert Bast Jr., an expert in ovarian cancer and vice president for translational research at the MD Anderson Cancer Center at the University of Texas, inserted gel-bound carbon nanotubes into the ovaries of rodents to mimic the accumulations that researchers expect for nanotubes linked to special antibodies that recognize tumor cells.

Researchers then scanned the rodents with the Rice University lab’s custom-built optical device to detect the faint emission signatures of as little as 100 picograms of nanotubes.

The device irradiated the rodents with intense red light from an array of light-emitting diodes and read fluorescent signals with a specialized sensitive detector. Because different types of tissue absorb emissions from the nanotubes differently, the scanner took readings from many locations to triangulate the tumor’s exact location, as confirmed by later MRI scans.

Weisman says it should be possible to noninvasively find small ovarian tumors within rodents used for medical research by linking nanotubes to antibody biomarkers and administering the biomarkers intravenously. The biomarkers would accumulate at the tumor site. He says more refined versions of the optical scanner may then be able to locate a tumor within seconds, and further advances may extend the method’s application to human cancer detection.

The new results suggest that antibody-nanotube probes could potentially detect tumors with as few as 100 ovarian cancer cells, which could make it a valuable tool for early detection.

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Additional coauthors of the study are from Rice University and the University of Texas.

The National Science Foundation, the Welch Foundation, the National Institutes of Health, the John S. Dunn Foundation Collaborative Research Award Program, the National Cancer Institute, the Cancer Prevention and Research Institute of Texas, the National Foundation for Cancer Research, the Mossy Foundation, Golfers Against Cancer, the Roberson Endowment, and Stuart and Gaye Lynn Zarrow supported the research.

Source: Rice University