Microscopic filter captures cancer cells circulating in blood stream

17 December 2012

A microscopic filter that can capture individual tumour cells from blood has been developed by the RIKEN Advanced Science Institute in Japan and University of California Los Angeles.

The nanoscale velcro-like filter can capture and release tumour cells that have broken away from primary tumours and are circulating in the bloodstream. It could enable detection of tumour cells that circulate in cancer patients’ blood well before they subsequently colonize as tumours in other organs.

The device also enables researchers to keep the tumour cells alive and subsequently study them. It could be used for cancer diagnosis and give insight into the mechanisms of how cancer spreads throughout the body. The device also provides a convenient and non-invasive alternative to biopsy, the current method for diagnosis of metastatic cancer.

Similar cell-capture devices have been reported but this technology is unique in that it is capable of catching the tumour cells with great efficiency and releasing them with great cell viability.

The filter contains a molecule capable of adhering to tumour cells like Velcro and separating them with efficiency ranging from 40% to 70%. The cancer cells are retained by tiny temperature-responsive polymer brushes inside the device. At 37°C, these polymer brushes stick to the tumour cells, but when cooled to 4°C, they release them, allowing scientists to examine the cells.

Diagram showing how the nanoscale filter operates
Diagram showing how the nanoscale filter operates

"Until now, most devices have demonstrated the ability to capture circulating tumour cells with high efficiency. However, it is equally important to release these captured cells, to preserve and study them in order to obtain insightful information about them. This is the big difference with our device." Explains Hsiao-hua Yu, who led the team that developed the technique to coat the device with polymer brushes.

Further information

Shuang Hou et al. Capture and Stimulated Release of Circulating Tumor Cells on Polymer-Grafted Silicon Nanostructures. Advanced Materials, 2012


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