Sugar Helps Fight Cancer
August 1, 2014
Capsules one billionth of a meter in size carrying a drug directly to tumor cells—this new cancer treatment technique has been developed by scientists from the Biomedical Engineering Laboratory at the Warsaw University of Technology.
The researchers have invented this method chiefly for the treatment of people with breast and colon cancer. In the future, however, the new technique can also be used in the treatment of other cancers such as leukemia, says Tomasz Ciach, Ph.D., who manages the research team. According to Ciach, the team plans to use tiny nanoparticles and equip these with special antibodies to envelop cancer cells with a coating of polysaccharides—sugars that are present in the human body.
Cancer cells need about 200 times more glucose than normal healthy cells, according to Ciach. “You could say that they have a soft spot for sugar, and we decided to take advantage of this weakness,” says Ciach. Tumor cells are extremely eager to suck in sugar nanoparticles. Once inside the tumor, the nanoparticle begins to fall apart and releases the drug it is carrying directly into the tumor.
The administration of the drug is additionally enhanced by the fact that new blood vessels form around the tumor that have a relatively chaotic structure and are not tight. Nanoparticles penetrate the tumor through these leaks. Such leaky blood vessels are formed when the tumor reaches the size of about half a millimeter and the ordinary supply of oxygen and food is not enough for it. It then begins to send special chemical signals as a result of which a new blood vessel grows out from the nearest blood vessel to ensure enough “food” for the tumor.
Studies on animals have shown that by administering a dose of a drug in nanoparticles, it is possible to obtain a more than five times greater concentration of it in the tumor than if the drug was administered in a different way. Once it finds itself inside the cancer cell, it stays there for even several weeks, destroying it from within. Several drugs can be administered at a time, which is important because tumors rapidly develop resistance to one drug. If several drugs with different mechanisms of action are administered simultaneously, cancer cells do not have a chance of developing resistance to them. Because the drug accumulates in the tumor itself and does not spread to other parts of the body, it can also be administered in a much greater quantities. And the side effects of such a therapy are smaller.
In their nanocapsules, the researchers primarily use dextran, a polysaccharide long known in medicine and used in eye drops, for example. This is a major advantage of the therapy, because this polysaccharide is completely harmless to the body. It is excreted through the kidneys and metabolized through the liver.
Another advantage of the new method developed by the Warsaw University of Technology researchers is that their nanocapsules are undetectable and invisible to the immune system. The task of the immune system is to look for any foreign bodies in the blood, so it quickly detects most nanoparticles that enter the body.
The nanocapsules are 95 percent made up of water with polysaccharide chains. As a result, the immune system does not see them. Otherwise they would be immediately filtered in the lymph nodes and removed from the body.
Nanocapsules can also come in useful for the detection of cancers of the esophagus and intestine and facilitate the surgical removal of such tumors. This will be possible after inserting fluorescent nanocrystals into the tiny capsules. Such crystals begin to shine after getting attached to the tumor cell.
The research team recently launched a study on animals. “If we’re lucky and have funds, we hope we’ll manage to begin tests on humans by the end of the 2015,” says Ciach. The team says it needs $30 million to continue its work, an amount too high to be covered with ordinary grants. Therefore Ciach has started a company and teamed up with a venture fund that is helping him raise money for research.