Economic filters that isolate circulating tumor cells


Researchers at Kumamoto University in Japan have designed an economical and convenient filter that can isolate circulating tumor cells from just 1 ml of patient blood. The highly sensitive filter can work successfully in samples that contain up to five tumor cells in 1 ml of blood and do not require expensive equipment or reagents, unlike certain pre-existing cell capture technologies. The filter can help develop diagnostic technologies that can help doctors identify cancer early.

Circulating tumor cells are those that have detached from a tumor and travel through the bloodstream. Although they represent a vector for cancer metastasis, circulating tumor cells are a largely unexploited diagnostic resource, with enormous potential to help physicians identify cancer early. If cells can be successfully isolated from a patient’s blood, they can provide an early warning signal that cancer is present, as well as a minimally invasive diagnostic marker, which requires only a small sample of blood.

However, isolating cells is easier said than done, as they are usually present only at very low concentrations. There can only be several of the tumor cells circulating in a milliliter of blood, while the number of white and red blood cells could easily stand at billions. A needle in a haystack doesn’t even come close.

Despite this, researchers have advanced in the development of technologies that can separate circulating tumor cells from whole blood samples. However, this technology can be bulky or expensive and can rely on expensive reagents, which limits its use. The latter technology uses nucleic acid aptamers and a unique design that allows regular blood cells to circulate, to make a relatively inexpensive filter.

The new filter deforms in three dimensions when blood is pumped through it, resulting in small openings that allow the passage of blood cells. However, this effect also causes intentional cell clustering and allows circulating tumor cells to come into contact with nucleic acid aptamers that are on the surface of the filter, resulting in binding and capture. The new device has already shown impressive sensitivity compared to pre-existing tumor cell isolation technologies.

“This work demonstrates that our microfilter device can accurately detect traces of cancer cells in the blood,” said Yuta Nakashima, a researcher involved in the study. “We hope it will be adopted for the diagnosis and treatment of cancer, including for the early diagnosis of cancers that cannot be detected by imaging, such as CT and PET, postoperative monitoring, recurrence control and tailor-made treatments. In the future , we plan to use blood samples donated by cancer patients to verify the practical and clinical application of the method ”.

Study the magazine Talanta: Detection of cancer cells in whole blood by means of a dynamic deformable microfilter and a nucleic acid aptamer

Via: Kumamoto University

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