An innovative device with nano-sized features developed by researchers at UCLA is able to grab cancer cells in the blood that have broken off from a tumour.
These cells, known as circulating tumour cells, or CTCs, can provide critical information for examining and diagnosing cancer metastasis, determining patient prognosis, and monitoring the effectiveness of therapies.
Metastasis – the most common cause of cancer-related death in patients with solid tumours – is caused by marauding tumour cells that leave the primary tumour site and ride in the bloodstream to set up colonies in other parts of the body.
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.
The UCLA team’s device is actually a 1 x 2cm silicon chip covered with densely packed nanopillars. 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 then coated with anti-EpCAM, an antibody protein that can help recognise and capture tumour cells.
The researchers found that the cell-capture yields for the UCLA nanopillar chip were significantly higher than the flat device – the device captured 45-65 per cent of the cancer cells in the medium, compared with only 4-14 per cent for the flat device.
Dr Shutao Wang, a postdoctoral researcher at both the Crump Institute for Molecular Imaging at the David Geffen School of Medicine at UCLA and the California NanoSystems Institute at UCLA, said: ‘The nanopillar chip captured more than 10 times the amount of cells captured by the currently used flat structure.’