Jul 1 2008
A novel technique for reducing tumors in rats-using nano-sized, oil-based emulsions may be the latest weapon in fighting cancer.
The technique, part of the burgeoning field of nutraceuticals, involves creating nanoemulsions, or nano-sized capsules made from oil and water. The emulsions, which are so small they are measured in nanometers—or 1/100 of a meter—are then filled with various antioxidants or anti-cancer fighting compounds, and tests show they can reduce tumors in rats.
Researchers at the University of Massachusetts Lowell injected rats with neuroblastoma, so they would develop tumors, and then treated them with nanoemulsions containing antioxidants. They found that while the rats fed in the control group continued to develop tumors, the growth rate for those fed antioxidants was actually negative 65 percent, meaning the tumors actually shrank.
“They had about 70 percent total tumor regression,” said Professor Robert Nicolosi, director of UMass Lowell’s Center for Health and Disease Research.
When researchers exposed melanoma cancer cells to a nanoemulsion containing curcumin, an anti-cancer compound found in turmeric, cancer cell proliferation was greatly reduced, Nicolosi said. And when they used a nanoemulsion containing tamoxifen, a drug used to fight breast cancer, they just about eliminated the ability of the cells to proliferate—at least in a cell culture, Nicolosi said. Nanoemulsion delivery systems have been shown to increase the bioavailablity and efficacy of certain drugs. The advantage, particularly for some of the toxic compounds used in fighting cancer, is that less of that compound is needed to achieve the same effect. That means the patient would suffer fewer damaging side effects.
“There’s no question we’re reducing the toxicity when we use 10 to 20 times less,” Nicolosi said.
Umass has been using Microfluidizer materials processing equipment to develop the nutraceutical products. The equipment has helped standardize the size of the nanoemulsions, making them more commercially viable. Prior to the Microfluidizer, nanoemulsions came out in varying sizes, making them less effective and less likely to gain approval by the US Food and Drug Administration, according to Scott McMeil, director of the Nanotechnology Characterization Laboratory at SAIC-Frederick, Inc.
“Nanoemulsions have been around for several years, but they weren’t very stable. But with a Microfluidizer, it looks like it’s overcoming the stability issue,” McNeil said.
McNeil, whose company is subcontracted by the National Cancer Institute, said the FDA requires that a compound is stable before it will grant its seal of approval. Before researchers began using the Microfluidizer, the size of the various nanoemulsions might vary from five nanometers to five microns, in one solution, making the solution less stable.
“A company would not move forward with something that was that high risk,” McNeil said. “The Microfluidizer has opened up new opportunities, such as nanoemulsions.”
In order to create the nanoemulsion, scientists mix water, an emulsifier like lecithin, and an antioxidant or anti-cancer fighting compound, and then pour it into a Microfluidizer processor. The processor then compresses the solution and drives it through tiny microchannels, and then in a reaction chamber, it splits the solution into two streams, which collide with each other at extremely high speeds. The collision creates a nanoemulsion that has a long shelf life.
Researchers, such as UMass are also using the Microfluidizer processors to create foods, beverages, and nutritional supplements that can reduce inflammation or inhibit the intestines ability to absorb cholesterol, thus reducing blood cholesterol levels as well as the risk of heart disease.