Magnetic Nanotags Spot Tumors

photo: sensor

The sensor searches for up to 64
different cancer-associated proteins
simultaneously; © Stanford Univ.

The sensor is up to 1,000 times more sensitive than any technology now in clinical use, is accurate regardless of which bodily fluid is being analyzed and can detect biomarker proteins over a range of concentrations three times broader than any existing method, the researchers say.

The nanosensor chip also can search for up to 64 different proteins simultaneously and has been shown to be effective in early detection of tumors in mice, suggesting that it may open the door to significantly earlier detection of even the most elusive cancers in humans. The sensor also can be used to detect markers of diseases other than cancer.

"In the early stage of a cancer, the protein biomarker level in blood is very, very low, so you need ultra-sensitive technology to detect it," said Shan Wang, professor of materials science and engineering and of electrical engineering.

Wang said the nanosensor technology also could allow doctors to rapidly determine whether a patient is responding to a particular course of chemotherapy. "We can know on day two or day three of treatment whether it is working or not, instead of a month or two later," he said.

The sensor Wang and his colleagues have created, which uses magnetic detection nanotechnology they had developed previously, can detect a given cancer-associated protein biomarker at a concentration as low as one part out of a hundred billion (or 30 molecules in a cubic millimeter of blood).

Although the basics of the magnetic detection technology used in the new biosensor were described last year in a paper in the Proceedings of the National Academy of Sciences, the new sensor is not only more sensitive than the previous one by several orders of magnitude, it also outperforms its predecessor – and detection methods now in use – in several other ways.

The most impressive performance is that the researchers have now demonstrated that the magnetic-nano sensor can successfully detect cancerous tumors in mice when levels of cancer-associated proteins are still well below concentrations detectable using the current standard methodology, known by the acronym ELISA.

MEDICA.de; Source: Stanford University