Many cancer cells have a protein, known as Epidermal Growth Factor Receptor (EFGR), all over their surface, while healthy cells typically do not express the protein as strongly. By conjugating the gold nanoparticles to an antibody for EFGR, suitably named anti-EFGR, researchers were able to get the nanoparticles to attach themselves to the cancer cells.
"If you add this conjugated nanoparticle solution to healthy cells and cancerous cells and you look at the image, you can tell with a simple microscope that the whole cancer cell is shining,” said Mostafa El-Sayed, director of the Laser Dynamics Laboratory and chemistry professor at Georgia Tech.
In the study, researchers found that the gold nanoparticles have 600 percent greater affinity for cancer cells than for noncancerous cells. The particles that worked the best were 35 nanometers in size. Researchers tested their technique using cell cultures of two different types of oral cancer and one nonmalignant cell line.
What makes this technique so promising, said El-Sayed, is that it doesn't require expensive high-powered microscopes or lasers to view the results, as other techniques require. All it takes is a simple, inexpensive microscope and white light.
Another benefit is that the results are instantaneous. "If you take cells from a cancer stricken tissue and spray them with these gold nanoparticles that have this antibody you can see the results immediately. The scattering is so strong that you can detect a single particle,” said El-Sayed.
Finally, the technique isn't toxic to human cells. A similar technique using artificial atoms known as Quantum Dots uses semiconductor crystals to mark cancer cells, but the semiconductor material is potentially toxic to the cells and humans.
"This technique is very simple and inexpensive to use,” said El-Sayed. "We think it holds great promise in making cancer detection easier, faster and less expensive.”
MEDICA.de; Source: Georgia Institute of Technology