JUST AS FLY PAPER CAPTURES INSECTS, an innovative new device with nano-scale features developed by researchers at UCLA is able to grab cancer cells in the blood that have broken off from a tumor. These cells, known as circulating tumor cells, or CTCs, can provide critical information for examining and diagnosing cancer metastasis, determining patient prognosis and monitoring the effectiveness of therapies.
The current gold standard for examining the disease status of tumors is an analysis of metastatic solid biopsy samples, but it is often difficult in the early stages of metastasis to identify a biopsy site. By capturing CTCs, doctors can essentially perform a “liquid” biopsy, allowing for early detection and diagnosis, as well as improved treatment monitoring.
To date, several methods have been developed to track these cells, but the UCLA team’s novel “fly paper” approach may be faster and cheaper than others – and it appears to capture far more CTCs. In a study published in Angewandte Chemie, the UCLA team developed a 1-by-2- centimeter silicon chip that is covered with densely packed nanopillars and looks like a shag carpet. To test cell-capture performance, researchers incubated the nanopillar chip in a culture medium with breast cancer cells. As a control, they performed a parallel experiment with a cell-capture method that uses a chip with a flat surface. Both structures were coated with an antibody protein that can help recognize and capture tumor cells.
The researchers found that the cell-capture yields for the nanopillar chip were significantly higher: The device captured 45-to-65 percent of the cancer cells in the medium, compared with only 4-to-14 percent for the flat device.
“We hope that this platform can provide a convenient and costefficient alternative to CTC sorting by using mostly standard lab equipment,” says senior study author Hsian-Rong Tseng, Ph.D., associate professor of molecular and medical pharmacology.