May 07, 2009, 4:39 PM — Scientists have long known that heat is an effective weapon against cancerous tumors. The problem, though, has been how to heat the tumors to the point that it kills them without damaging surrounding tissue.
Now researchers MIT think they have the answer: nanotechnology.
The school announced this week that the researchers have developed gold nanoparticles that can target tumors and heat them with minimal side effects to nearby healthy cells. While the gold nanorods were used in the study to find and hone in on tumors, they also might be able to diagnose cancer, according to MIT graduate student Geoffrey von Maltzahn, who worked with Sangeeta Bhatia, a professor in the Harvard-MIT Division of Health Sciences and Technology, to develop the nanoparticles.
The researchers said that tumors in mice that received the nanorod treatment disappeared within 15 days. The cancer did not reoccur for the duration of the three-month study.
This news comes just months after MIT announced that a group of scientists there had developed nanotechnology that can be placed inside living cells to determine whether chemotherapy drugs used to treat cancer are reaching their targets or attacking healthy cells. Researchers use carbon nanotubes wrapped in DNA so they can be safely injected into living tissue.
And last August, scientists at Stanford University reported that they had found a way to use nanotechnology to have chemotherapy drugs target only cancer cells, keeping healthy tissue safe from the treatment's toxic effects.
And that news came on the heels of a report out last July noting that researchers at the University of California, San Diego, had discovered a way to use nanotechnology-based "smart bombs" to send lower doses of chemotherapy to cancerous tumors, thus cutting down the cancer's ability to spread throughout the body.
Cancer researchers have long been trying to figure out a way to better attack cancer cells without harming surrounding cells as well. That has been one of the major drawbacks of chemotheraphy and radiation therapy, which often have debilitating side effects because of the difficulty in targeting just the cancerous tissue.
According to MIT, cancer affects about 7 million people a year worldwide, and that number is projected to jump to 15 million by 2020. Most of those patients are treated with chemotherapy and/or radiation and 99% of those drugs typically don't reach the tumor, said von Maltzahn.
He added that their work with the gold nanorods is the "most efficient method" in targeting tumors yet developed.
The nanoparticles work in this cancer treatment by absorbing light at near-infrared frequency. The light heats the rods but passes harmlessly through human tissue, said von Maltzahn. The nanoparticles accumulate in the tumors, and within three days, the liver and spleen clear any that don't reach the tumor.
The mice that were treated in the MIT study received an injection of the gold nanorods along with near-infrared laser treatment. With this combination therapy, the tumors disappeared and did not return in the duration of the scientists' research.