When it comes to searching out cancer cells, gold may turn out to be a precious metal.
Purdue University researchers have created gold nanoparticles that are capable of identifying marker proteins on breast cancer cells, making the tiny particles a potential tool to better diagnose and treat cancer. The technology would be about three times cheaper than the most common current method and has the potential to provide many times the quantity and quality of data, said Joseph Irudayaraj, an associate professor of agricultural and biological engineering.
"We hope that this technology will soon play a critical role in early detection and monitoring of breast cancer," said Irudayaraj (pronounced ee-roo-THY'-a-razh), leader of a research team that developed a new method for fabricating the nanoparticles that is published online this month in the journal Analytical Chemistry. "Our goal is to see it in commercial use in about four years."
The gold nanoparticles, or nanorods, are tiny rod-shaped gold particles, even smaller than viruses, which are equipped with antibodies designed to bind to a specific marker on cell surfaces. Researchers analyze these surface markers, proteins on a cell's exterior, because they can contain valuable information about what type of cell they belong to or what state that cell may be in.
"In cancer diagnosis, the ability to accurately detect certain key markers will be very helpful because certain types of cancers have specific surface markers," Irudayaraj said.
In another study published last month in Nano Letters, Irudayaraj showed that the nanorods, when combined with a special imaging technique, were capable of recognizing cancer stem cells by binding to known markers on their exterior. Cancer stem cells are important to detect because they are particularly invasive and more likely than other types of cancer cells to spread, or metastasize, to other organs. These and other types of cells the technology utilizes are obtained from blood tests as opposed to biopsies.
The nanoparticles, or "gold nanorod molecular probes," are fabricated so that their size is unique to their target marker. That way, when nanorods bind to their marker, they "scatter," or disrupt light in a characteristic manner that researchers can then pair to the nanorod's dimensions, its antibody and the target cancer marker, which must be present for binding to occur.
More than 200,000 women are diagnosed with breast cancer every year in the United States, and 80 percent of those women receive some type of therapy, Irudayaraj said. Since 40 percent of them will have a relapse, regular monitoring, which this technology aims to do, is vital.