Allergy nanomedicine: buckyballs dampen response of cells that trigger allergic reactions.

Scientists have shown that soccer ball--shaped carbon molecules, commonly called buckyballs, can block allergic responses in both human cells and mice. The findings point to a new way of treating allergies using these nanoscale particles.

In recent years, several labs have begun harnessing the unusual physical and chemical properties of buckyballs to develop new drugs and diagnostic tools (SN: 7/13/02, p. 26). A buckyball consists of 60 carbon atoms arranged in a hollow, spherical shape. Scientists can easily modify the molecule's properties by attaching different chemical entities to its surface.

Several studies suggest that buckyballs act as strong antioxidants, or "free radical sponges," says Chris Kepley, an immunologist at Virginia commonwealth University in Richmond. In other words, they appear to sop up free radicals and other chemical species containing reactive oxygen, which are natural by-products of energy production in cells. Free radicals, which damage cellular structures, may be an important cause of aging and many neurological diseases.

Since studies have also linked allergic responses to increases in reactive oxygen species, Kepley and his colleagues wondered whether buckyballs could quell allergies. The researchers exposed two types of human cells--mast cells and basophils--to water-soluble buckyballs for 24 hours. Both cell types store histamine, the chemical that induces allergic reactions.

When the researchers triggered an allergic response in the buckyball-exposed cells, the cells released significantly less histamine than expected. In contrast, unexposed cells generated the full allergic response.

Kepley and his colleagues also injected mice with a solution of buckyballs and then triggered an allergic reaction that would normally cause the animals to experience anaphylactic shock. The buckyballs blocked the animals' anaphylactic response by dampening the release of histamine. The researchers report their results in the July 1 Journal of Immunology.

"This is a great proof of principle that these molecules can act as good antioxidants," says Laura Dugan, a geriatric specialist at the University of California, San Diego, whose lab is also testing buckyballs for the treatment of allergies. Dugan says that the new results are in line with her own group's unpublished findings.

"There is an enormous future for these compounds," she says. "It's a whole new approach to treating a lot of different diseases." For instance, Dugan's lab is testing the possible use of buckyballs against Parkinson's disease and Alzheimer's disease. Kepley plans to investigate the use of buckyballs to prevent arthritis and diabetes.

The next step in the allergy work will be to chemically modify buckyballs so that they target only mast cells or basophils in the body, says Kepley. Although toxicity is a concern with nanoparticles, the buckyballs in his study didn't appear to be toxic to either the cells or the mice. But more tests are needed to ensure the molecules' safety, says Kepley.

His group is collaborating with Luna Innovations, a company in Danville, Va., to turn buckyballs into a new treatment for allergies.