Redesigned Microchip Device is Effectual in Tumor Cell Capture

The microchip is mounted on a standard glass slide, which allows the use of standard pathology tests to identify cancer cells, and the device can be easily opened, giving access to CTCs for additional testing and growth in culture.

The Herringbone (Hb) Chip was developed at the Massachusetts General Hospital, (Boston MA, USA) and uses a microvortex –generating principle. The HB-Chip design applies passive mixing of blood cells through the generation of microvortices to increase significantly the number of interactions between target CTCs and the antibody-coated chip surface. The new device also may provide more comprehensive and easily accessible data from captured tumor cells and is easier to manufacture. CTCs are living solid tumor cells found at extremely low levels in the bloodstream; the Hb-Chip can process large-volume blood samples, increasing the ability to find these rare cells.

Experiments comparing the HB-Chip to the original CTC-chip found the new device captured more than 90% of cancer cells introduced into a blood sample, which is a 25% improvement over the CTC-chip. Tests of samples from cancer patients found the redesigned device at least as effective as the original. CTCs were detected in 14 of 15 (93%) patients with metastatic disease (median = 63 CTCs/mL, mean = 386 ± 238 CTCs/mL), and the tumor-specific translocation markers were readily identified using molecular techniques. The transparent materials used in the manufacture of the HB-Chip made it possible to complement immunofluorescence staining of CTCs with stains used in standard pathology laboratories to identify tumor cells using light microscopy. The HB-Chip also captured clusters of 4 to 12 CTCs from several patient samples but not from samples to which cancer cells had been added. No previous technology for capturing CTCs has ever found such clumps of tumor cells.

Daniel Haber, M.D., Ph.D., coauthor of the study said, "This new technology is a powerful platform that will enable increasingly sophisticated analyses of metastasis and support clinical research in targeted cancer therapies." The study was published in the October 2010 edition of the Proceedings of the National Academy of Sciences (PNAS).

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