Gold Against Cancer - A breakthrough method
By: Stefan Anitei, Science Editor - Softpedia
Health is wealth. Gold dust could be the new powerful anti-cancer weapon, transporting drugs hidden from the body's immune cells into tumors. Drug molecules have been attached to gold particles of just a fraction of the diameter of a human hair, so tiny that they can sneak blood's white cells without being annihilated and launch the cancer-destroying molecules into the core of the tumor.
The method developed by a team at Rice University in Houston, Texas, could eliminate nasty side-effects suffered by patients undergoing chemotherapy, like hair loss, nausea and vulnerability to infections (as toxins inhibit the immune system). All the side-effects are due to the fact that chemotherapy kills both cancer and healthy cells.
The gold dust therapy could decrease the level of required toxic drugs, as these enter mainly the tumor.
Taxol is a common chemotherapy drug employed for cases of breast or ovarian cancer, being extracted 40 years ago for the first time from the bark of the yew tree. The molecule binds to the framework inside a cell, emerged during division (the inner framework allows the old cell to divide into two new ones). This way Taxol prevents that breakdown, stopping the multiplication of the cancer cells.
The effectiveness of Taxol and other chemotherapy chemicals would increase due to a selective transport to the malignant cells by the gold particles.
Gold is non-toxic (thus safe for the body) and has a history in medicine. Since the 1930s, rheumatoid arthritis has been prevented with gold jabs to decrease swelling in knees and wrists.
A 2007 research presented the use of gold particles for the diagnosis of breast cancer and other types. Gold dust bound to antibodies was transported to the tumor site. A scan reveals after that the location of the gold particles. This new research goes much further.
"The size of the particles is crucial to the success of the treatment." said lead researcher Professor Eugene Zubarev.
The gold particles are just 2 nanometres wide (5,000 times less than a human hair).
"That small size allows them to avoid fast removal by the immune system. If they were much bigger, they could be destroyed long before they reach their target. This small size is also important because it allows them to pass through holes in tumor blood vessels. In general, the blood vessels that feed a tumor have lots of holes in them up to 1,000 nm in diameter. This makes them leaky and means they allow the small gold particles to leave the blood stream and accumulate inside the tumor. Healthy blood vessels, on the other hand, don't have too many of these holes." said Zubarev.
After that the gold particles reach the liver before being expelled through the body's waste products.
"Gold is perfect because it gets underneath the immune system and does not get rejected by the body. But it's not expensive because the quantities of gold involved are minute. We're talking pennies. In fact, it's the drugs that are used which cost the money." said Professor David Russell, from the University of East Anglia, studying a similar golf technique for delivering drugs into tumors.