A number of technologies have been invented in recent years for capturing circulating tumor cells (CTCs) from whole blood. There are limitations to all of them, and one common problem is keeping the cells alive while removing them from the screening device. This is normally due to the same mechanism that grabs on to the circulating tumor cells and doesn’t let them go. A couple of years ago we wrote about the NanoVelcro microfluidic device that effectively harvests CTCs from blood, but it suffered from the same problem and required specialized equipment and laborious effort to remove the captured cells. Now the research team has developed a pretty simple release method so the cells can go under the microscope for analysis.
As the name implies, the NanoVelcro chip has a hairy array of nanoscale wires, each with antibodies of proteins found in CTCs at the tips. As the blood passes by the wire hairs, the CTCs stick to them. In the process of figuring out how to detach the cells, the team discovered that by lowering the temperature of the environment around the hairs from body temperature to 4° Celsius, the cells pop off and can be collected in pure, undamaged form. If everything goes as planned, we may see CTC capture devices being utilized in clinical practice for early screening and monitoring of cancer post treatment.
“With our new system, we can control the blood’s temperature — the way coffeehouses would with an espresso machine — to capture and then release the cancer cells in great purity, ” said Hsian-Rong Tseng, a professor of molecular and medical pharmacology at UCLA. “We combined the thermoresponsive system with downstream mutational analysis to successfully monitor the disease evolution of a lung cancer patient. This shows the translational value of our device in managing non–small-cell lung cancer with underlying mutations.”