A team of researchers at Daegu Gyeongbuk Institute of Science & Technology in Korea created a centrifugal system to separate circulating tumor cells from blood samples. Resembling a DVD, the device separates the cells using the centrifugal force created when it is spun. A layer of white blood cells and circulating tumor cells is formed during the spinning process and then antibody-studded magnetic beads bind and remove the white blood cells, leaving the circulating tumor cells in the final sample. The technique isolates a variety of different tumor cell types, allowing clinicians to get a better idea of the cancer, how to treat it, and maybe even detect it in the first place.
Circulating tumor cells represent a tantalizing way to assess a tumor. These cells consist of either individual cells or small clumps of cells that break away from a solid tumor and spread throughout the blood, potentially forming the basis for metastases. While the metastatic potential of circulating tumor cells is undoubtedly worrying for patients, they represent a diagnostic opportunity in the form of liquid biopsies.
Obtaining tumor biopsies can be inconvenient for patients and clinicians alike, and simply taking a blood sample and isolating the circulating tumor cells could provide a less invasive and more practical way to determine the biomolecular characteristics of a tumor. However, tumor cells are present at very low levels in blood and isolating them is a challenge. The field is still in its relative infancy and the current techniques for isolating tumor cells from blood have met with mixed success. Some techniques are highly specialized and require laborious work while others may miss certain types of tumor cell, providing an incomplete picture of the tumor.
To address this, these researchers have created a fully automated technology that requires a user to add a blood sample, and then centrifugation, antibodies, and magnets do the rest. “Our smart and practical approach realizes a big dream in the field of liquid biopsy and demonstrates high performance across a wide range of cell types and different cancers with full automation,” said Minseok S. Kim, one of the creators of the new device.
The researchers have dubbed their technology “Continuous Centrifugal Microfluidics – Circulating Tumor Cell Disc”. Once the blood sample is added, a machine spins the disc, causing the blood to separate into its constitutive layers, one of which contains both circulating tumor cells and white blood cells.
While the disc is spinning, a laser motor opens a valve, allowing the layer containing these cells to run into a separate chamber. In this chamber, magnetic beads studded with antibodies bind the white blood cells and then a magnet holds them in place while the circulating tumor cells enter the final chamber for analysis. Unlike some other techniques, the researchers claim that this new method isolates all types of circulating tumor cell.
Study in journal Theranostics: Continuous centrifugal microfluidics (CCM) isolates heterogeneous circulating tumor cells via full automation