A team of researchers at Worcester Polytechnic Institute led by Prof. Balaji Panchapakesan have developed a chip made of carbon nanotubes that can capture circulating tumor cells of all sizes and types.
The Worcester, MA-based leading institute said in a news release that the chip can capture those cells with far greater sensitivity than existing technologies.
The unique design of the device makes it possible to easily identify and even culture the captured cells, which could make it possible to detect early-stage tumors, predict the course of cancer, and monitor the effects of therapy, it said.
Details of the new technology were reported in the journal Lab on a Chip by a team consisting of researchers at WPI, the Department of Neurological Surgery at the University of Massachusetts Medical School, and the James Graham Brown Cancer Center at the University of Louisville School of Medicine.
“Isolating CTCs with high purity is a significant challenge, akin to finding a needle in a haystack,” Panchapakesan said in the report. “These cells comprise as few as one to 10 cells among a billion blood cells, and the shedding of CTCs from tumors is a highly discontinuous process.”
Dr. Panchapakesan is the director of the Small Systems Laboratory (SSL) at WPI, which is dedicated to the development of multi-functional materials, devices and systems at the macro-, micro-, meso- and nanoscales. He invented the Nanotube-CTC-Chip. He has published over 100 articles in leading journals and conferences.
High cancer mortality rates are largely attributable to tumors developing undetected until they reach advanced or inoperable stages, and to metastasis. Scientists have long sought a method that can reliably snare tumor cells as they travel through the bloodstream.
Such technology could make it possible to detect cancers at very early stages, when treatment is more likely to be successful, and to spot the genetic changes that tumor cells undergo when a cancer is beginning to metastasize, the WPI report said.
A number of research labs and companies have created so-called liquid biopsy devices, but the devices currently available have important limitations, Panchapakesan said.
These include low sensitivity; the inability to trap CTCs of all sizes and types, or to capture clusters of CTCs along with individual cells; difficulty in retrieving captured cells from the devices for laboratory analysis; and high manufacturing costs. In addition, contamination of captured CTCs by white blood cells, which are similar in size to and can be mistaken for CTCs, is a problem for many liquid biopsy devices, the report said.
The device developed by Panchapakesan’s team, described in the Lab on a Chip paper, has none of these limitations, it noted.
The centerpiece of the device is a layer of carbon nanotubes that lines the bottom of a small well-formed in a silicon/glass wafer. Panchapakesan says the chip design takes advantage of a natural tendency of CTCs to attach.
“In order to travel to a distant site in the body and start a new tumor,” Panchapakesan said, “CTCs need the ability to attach in an environment that is not conducive to the attachment. In previous research, we have shown that they will attach preferentially to carbon nanotubes, but that white blood cells will not, by and large.”
Panchapakesan said he believes the latest generation of carbon nanotube liquid biopsy chip is ready for clinical trials.
Toward that end, he is working with StrandSmart Inc., a Silicon-Valley start-up led by CEO Adrianna Davies. The team envisions testing a point of care device to detect cancer in the earliest stages globally, WPI said.
