Associated Press Writer
LITTLE ROCK, Ark.—Tiny carbon tubes measured in the billionths of a meter can latch onto cancer cells, allowing them to be targeted for laser incineration without damaging healthy cells nearby, two Arkansas university researchers said Monday.
The findings, by Alex Biris of the University of Arkansas at Little Rock and Vladimir Zharov of the University of Arkansas for Medical Sciences, show how the emerging science of nanotechnology could be used in place of chemotherapy or surgery in cancer treatment. However, both scientists acknowledged that more testing needs to be done to determine whether the tubes could be toxic to human patients.
The scientists injected cervical cancer cells into rats near their ear, allowing the cells to reach the animal's lymph nodes. Once cancer cells from tumors reach the lymph nodes, the disease can spread to other organs of the body.
The researchers injected the carbon tubes into the rats, which latched onto the cells. Using a device similar to an MRI machine, the scientists could watch the tube-attached cancer cells travel through the body.
"Now we have the ability by shining lasers, just lasers, to actually detect how these cancer cells move" through the circulation system, as well as lymph nodes and tissues, Biris said. "This is so important because, besides the ability to detect these cancer cells, we also want to be able to kill them."
To destroy the cells, scientists use a focused laser beam to heat up the carbon tubes to around 90 degrees Celsius. That provides enough energy to destroy the cancer cells and their DNA strains, but not to damage the cells surrounding the malignant material.
"It heats up single cells," Zharov said. "We tried to develop a biological Enola Gay to deliver at exactly the nano particles."
In the future, the researchers said such nanotubes could be injected into a cancer patient, and laser beams then used to destroy the cancer cells they attach themselves to. Zharov has received a five-year, $1.5 million grant through the National Cancer Institute to start a clinical trial to track cancer cells using the technology.
Such technology could reduce or eliminate the need for surgery or chemotherapy. Surgery carries risks and chemotherapy, while destroying cancerous cells, also indiscriminately destroys healthy cells as well.
Still, much remains unknown about how human bodies respond to the carbon nanotubes. A study last year found mice injected with some carbon nanotubes responded as if they had been exposed to asbestos, suffering from inflammation and lesions.
The two Arkansas researchers acknowledged the unknowns in an article they wrote for the Journal of Biomedical Optics, noting that "additional studies are required to understand the potentially toxic effects" of using the tubes in humans.