A cross-discipline project that brings together biomedicine and nano-engineering has led to the development of a dime-sized microfluidic device that can rapidly detect cancer cells in a blood sample. The new device is based on a cancer cell-detector created four years ago by Mehmet Toner, professor of biomedical engineering at Harvard Medical School. In its latest incarnation, carbon nanotubes have been introduced into the design resulting in an eight-fold improvement in the collection of cells.
The original version of the device – which is currently undergoing hospital tests with a view to commercialization – uses a forest of tiny silicon posts coated with antibodies to capture tumor cells from a blood sample. The aim is to detect circulating tumor cells which indicate that a cancer has metastasized, but because only a handful of these tumor cells are found among billions of normal blood cells, this is a big challenge. The drawback with this version of the device is that not all of the cells come into contact with the silicon posts.
With the assistance of Brian Wardle, an MIT associate professor of aeronautics and astronautics, the silicon tubes have now been replaced with porous carbon nanotubes just 30 microns in diameter which filter the blood far more effectively and therefore significantly improve the chances of collecting circulating tumor cells.
Because the nanotubes can be coated with different antibodies, the device also has great potential in other areas such as HIV diagnosis and could lead to the creation of versatile, low-cost handheld diagnostic devices that would be particularly beneficial in developing countries.
Details of Professor Toner's microfluidic device were published in the March 17 online edition of the journal Small.