New Device Uses Nanotubes to Catch Cancer Cells
These posts, made of carbon nanotubes, can trap cancer cells and other tiny objects as they flow through the device. Each post is 30 microns in diameter.
CREDIT: Brian Wardle
A new device has the ability to revolutionize the way doctors determine if cancer has spread from its original site within a patient's body. Researchers from Harvard and MIT have designed the dime-sized device which can detect single cancer cells in a blood sample.
Circulating tumor cells (cancer cells that have broken free from the original tumor) are normally very hard to detect, because there are so few of them — usually only several cells per 1-milliliter sample of blood, which can contain tens of billions of normal blood cells . However, detecting these breakaway cells is an important way to determine whether a cancer has metastasized.
"Of all deaths from cancer, 90 percent are not the result of cancer at the primary site. They’re from tumors that spread from the original site," said Brian Wardle, an MIT associate professor of aeronautics and astronautics, who helped develop the device.
In an attempt to capture these cells , Mehmet Toner, a biomedical engineer at Harvard, developed a device that could trap the tumor cells. In Toner's original device, blood taken from a patient flowed past tens of thousands of tiny silicon posts coated with antibodies that stick to tumor cells, trapping any cancer cells that touch the posts.
The only problem with this device was that there was no guarantee that the cancer cells would encounter the posts in the first place. He realized if the silicon posts were porous, the blood could flow through them instead, forcing cancer cells to come in contact with the antibodies, which is where Wardle came in.
When designing advanced materials, Wardle often uses carbon nanotubes — tiny, hollow cylinders whose walls are lattices of carbon atoms. Assemblies of the tubes are highly porous: A forest of carbon nanotubes, which contains 10 billion to 100 billion carbon nanotubes per square centimeter, is less than 1 percent carbon and 99 percent air. This leaves plenty of space for fluid to flow through.
The MIT/Harvard team placed various geometries of carbon nanotube forest into the microfluidic device. As in the original device, the surface of each tube can be decorated with antibodies specific to cancer cells. However, because the fluid can go through the forest geometries as well as around them, there is much greater opportunity for the target cells or particles to get caught.
The researchers hope that their device could eventually be developed into low-cost tests for doctors to use in developing countries where expensive diagnostic equipment is hard to come by, and they are currently working on tailoring the device for HIV diagnosis.
The device is currently being tested in hospitals and should become available in the next few years.
This article was provided by InnovationNewsDaily, a sister site of TechNewsDaily.
- Researchers Use Smartphones to Detect Cancers
- Making Nerves Glow Could Make Surgery Safer
- 10 Profound Innovations Ahead