New Microfluidic System Enables Early Cancer Diagnosis Using Simple Blood Tests

Circulating tumor cells (CTCs), which break off from primary tumors and travel through the bloodstream, pose a significant risk by forming secondary tumors in other organs. Detecting and analyzing these cells can play a crucial role in diagnosing and treating various cancers. However, the efficient capture of CTCs from blood has proven to be difficult, especially given the complexities and costs associated with incorporating antibodies into micro-sized devices. Although microfluidic systems using antibodies have shown promise, incorporating antibodies into specific regions of microscale devices involves complex chemical processes, ultimately raising production costs and hindering scalability. Now, scientists have developed a simple, cost-efficient microdevice that can detect cancer cells from blood with high sensitivity.

This novel microfluidic diagnostic device, developed by researchers at Chiba University (Chiba, Japan), incorporates microcone arrays to enhance the capture of cancer cells from blood. The team fabricated the device by imprinting polycarbonate (PC) sheets with microcone arrays using thermal nanoimprint lithography (T-NIL), a heat-based microfabrication technique. These microcones, approximately 30 micrometers in size, were arranged in a hexagonal pattern and featured nanometer-scale surface roughness that allowed for efficient binding of anti-human epithelial cell adhesion molecule antibodies. The antibody-coated PC sheets were sandwiched between a glass slide and a flat plate to form microchannels. The scientists tested various orientation angles of the microcone arrays within the microchannels to evaluate their influence on cancer cell capture behavior.

During experimental testing, the microfluidic device successfully captured human breast cancer (MCF-7) and human lung cancer (A549) cells from blood samples. The findings, published in Lab on a Chip, show that the device maintained a capture efficiency of over 90% for MCF-7 cells even at high flow rates, particularly when microcone orientation angles were set at 15° or 30°. To further demonstrate the system’s diagnostic capability, the researchers also performed immunostaining using fluorescent dyes to label and observe specific proteins in the captured cells. The labeled cancer cells remained trapped within the microchannels and could be easily distinguished from normal cells under fluorescence microscopy. This diagnostic device presents a highly sensitive and minimally invasive approach to cancer detection. It may also aid in monitoring treatment efficacy and identifying cancer recurrence through simple blood tests.

"We hope that through our new microfluidic system, even simple blood tests can be utilized to aid in the early diagnosis of cancer. It may also be useful for verifying the effectiveness of cancer treatment and monitoring recurrence after treatment," said Professor Masumi Yamada, lead developer of the device.

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Chiba University