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MIT, Harvard Team on Microfluidics Device To Detect Single Cancer Cells

by Editor1 last modified March 29, 2011 - 11:59

Researchers at Harvard and MIT have designed and built a sensitive new microfluidic device to detect single cancer cells in a blood sample. The work, based on carbon nanotubes, could better allow doctors to quickly determine the spread of cancers, HIV and other viruses.

MIT, Harvard Team on Microfluidics Device To Detect Single Cancer Cells

Harvard and MIT scientists are using antibody-coated CNTs and microfluidics to detect single cancer cells

The device is about the size of a dime and uses tens of thousands of porous carbon nanotube-based posts coated with antibodies. As blood cells passes through the posts, tumor cells are caught because the antibodies will adhere to those cells, according to co-designer Dr. Mehmet Toner, professor of biomedical engineering at Harvard Medical School.

To design the device, Toner enlisted the help of Brian Wardle, an expert in designing with nano-engineered advanced composite materials such as CNTs. Wardle is an MIT associate professor of aeronautics and astronautics.

Detecting free-floating tumor cells is one important way to determine whether a cancer has metastasized, the researchers said. "Of all deaths from cancer, 90 percent are not the result of cancer at the primary site. They're from tumors that spread from the original site," Wardle said.

Detecting free-floating cancer cells, those that have broken away from the original tumor and now circulating in the blood, can be extremely difficult. This is because there are so few of them. There may be only several cells in a sample of one milliliter of blood, (which contains tens of billions of blood cells), the team said.

Wardel brought his experience using CNTs for designing high-strength composite materials for aviation to the microfluidic project. He noted CNT cylinders are uniquely suited to micro- and nanofluidics because CNTs are hollow cylinders whose walls are lattices of carbon atoms so they are highly porous. In fact, assemblies of 10-100 million CNTs will contain less than 1 percent carbon and 99 percent air, which leaves plenty of space for fluid to flow through, Wardel explained.

The microfluidic device can be customized for various sized objects, allowing the device to be used for many cancers and viruses, the researchers said. The MIT/Harvard team can arrange the CNTs in various geometries on the microfluidic device for best affect. Further, each CNT can be coated with antibodies specific to cancer cells.

Tumor cells are typically about 1 micron in diameter; viruses measure about 40 nanometers in diameter.

The MIT-Harvard team are now working on tailoring the device for HIV diagnosis.

The work is described in the March 17 online edition of the journal Small