New Liquid Biopsy Chip Allows to Trap Cancer Cells Easily

Worcester Polytechnic Institute (WPI) researchers have developed a new chip that traps and identifies metastatic cancer cells within a tiny amount of blood drawn from a cancer patient. Liquid Biopsy technique helps to capture and identify tumour cells and/or DNA.

This technology uses a simple mechanical method, which is efficient in trapping cancer cells than the micro fluidic approach used in many existing devices.    

Antibodies attached to an array of carbon nano tubes at the bottom of a tiny well are used by the new device. Moreover, cancer cells settle to the bottom of the tiny well to connect to the antibodies based on their surface markers.

Liquid Biopsy Chip will detect early signs of metastasis and help physicians select treatments targeted at the specific identified cancer cells. Using this technology, tumour cells can be captured with high precision.

The device contains an array of tiny elements, each about a tenth of an inch (3 millimetres) across. Each element has a well at the bottom, where antibodies are attached to carbon nano-tubes.

Each well holds a specific antibody that will bind selectively one type of cancer cell type, based on genetic markers on its surface. Using this device, various cancer cells types that use a single blood sample can be captured.

In the lab, the researchers were capable to fill a total of 170 wells using just under 0.3 fluid ounces (0.85 mL) of blood. They also captured between one and a thousand cells per device, with a capture efficiency of between 62% and 100% using that small sample.

The carbon nano tubes used in the device act as semiconductors, when a cancer cell binds to one of the attached antibodies, it creates an electrical signature that can be detected. Cancer cells that are captured in the array can be identified by these signals.

Those individual arrays can then be removed and taken to a lab, where the captured cells can be stained and identified under a microscope. Electrical signature generation and the binding process take a few minutes and they also suggest the possibility of getting same-day results from a blood test using the chip.

Circulating tumor cells and exosomes are captured directly on the chip using this device. It would also increase its capability to detect metastasis.

Moreover, the WPI device is also highly effective in separating cancer cells from the other cells and material in the blood through differential settling that sets the new chip apart from current micro-fluid designs.

This device uses a passive leukocyte depletion strategy. Initially, the chip is used to detect breast cancer, but the WPI team noted that the device could be set up to detect a wide range of tumor types, and plans for other cancer types, including lung and pancreas cancer.