December 1, 2008 Plant biologists and immunochemists developed a way to produce rubber from a desert plant called guayule. The plant contains a natural rubber alternative without the proteins that trigger allergic reactions to latex. To release the rubber from their aqueous solution in the bark, scientists grind up the plant. Because the rubber particles are lighter than water, spinning the solution in a centrifuge causes the rubber to separate and settle at the top.
Since the 1980s, latex gloves have been an important part of preventing the spread of infectious diseases like MRSA, HIV and AIDS. In fact, ten billion latex gloves are used every year in the United States. As we use more latex, more people are developing dangerous allergies to it. Scientists have developed a new, natural alternative that may solve the problem.
Faith, Lamar and David Ryberg love games -- but that's not all they have in common. They all have Spina Bifida. Like 68 percent of kids with this birth defect, all three have dangerous allergies to latex.
"You just get kind of nervous you could stop breathing at any moment," Lamar said.
Three million Americans and as many as 17 percent of healthcare workers in the United States have latex allergies. Reactions range from skin irritations and wheezing to a sudden drop in blood pressure, anaphylactic shock and even death. Scientists say a desert plant called guayule offers a new, natural rubber alternative without the proteins that trigger allergic reactions.
Katrina Cornish, Ph.D., a plant biologist and immunochemist at the Yulex Corporation in Maricopa, Ariz., says the key to processing guayule is to release the rubber contained in the plant. It starts with a sort of guayule milkshake.
"We take the whole shrub and grind it up to release the rubber particles, which are made in the bark into an aqueous medium," said Dr. Cornish.
Rubber particles in the mixture are slightly lighter than water. By spinning the solution in a centrifuge, the rubber separates, forming a liquid that rises to the top. Dr. Cornish says not only is this latex alternative, called Yulex, safer for those with allergies -- products made with it are more flexible and stronger than latex. In this test, the Yulex on the left stood up to nearly twice as much force as the purple latex on the right.
Uses for guayule latex are virtually endless.
"So far, we haven't found anything made out of rubber that we can't make with guayule," Dr. Cornish said. It's a new kind of rubber that might just fit like a glove for the millions with latex allergies, like Lamar.
"It would be very, very good!" Lamar exclaimed.
Yulex recently received FDA approval for a medical examination glove. Researchers say it's comparable in price to high-end synthetic latex. Because over 50 percent of rubber products now available are petroleum-based, Yulex could become even more attractive as oil prices increase.
WHAT IS GUAYULE? Guayule is a plant native to North America that grows well in arid areas of the southwestern United States and in Mexico. The plant produces resins that act as natural pesticides, making guayule resistant to many pests and diseases. The bark of the guayule contains rubber, but it does not contain the allergy-causing proteins present in the plants that are used to make latex. Guayule rubber has comparable strength to that of synthetic latex, but is softer and more elastic.
WHAT ARE ALLERGIES? Every year, when spring rolls around, millions of Americans start sneezing and coughing. Allergies are the culprit. An allergy is simply a negative reaction to a substance that enters the body that is not toxic in itself, yet for some reason causes a bad reaction in the body. Just about anything can be an allergen: dust mites, pollen, cats, dogs, wasps or bees, milk, eggs, peanuts, and even fruits are the most common.
A normal immune system is the body's defense against invading bacteria and viruses. It senses potential invaders and attacks them by producing antibodies. But sometimes a person's immune system mistakes a common allergen as harmful. So it produces antibodies to attack them, and this triggers other cells to release chemicals called histamines, causing allergic symptoms. The most common symptoms of an allergic reaction include sneezing, swelling, itchy eyes, sinus pain, a runny nose, rashes or hives, coughing, and in some cases, vomiting. In extreme cases, an allergen can cause difficulty in breathing. This is called an anaphylactic reaction, and a severe attack can be fatal if not treated quickly.
The Materials Research Society and the American Industrial Hygiene Association contributed to the information contained in the TV portion of this report. This report has also been produced thanks to a generous grant from the Camille and Henry Dreyfus Foundation, Inc.
Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.