Developments to Watch
Edited by Adam Aston
Food Research Reaches a Nano Level
A fresher taste, a stronger aroma, and a higher absorption rate for food nutrients. These are just some of the benefits Kraft Foods is hoping to achieve with supersmall capsules made by wrapping one liquid around another.
Manuel Marquez, a chemist in Kraft's Glenview (Ill.) nano-tech lab, and his co-researchers found a way to force two flows of liquid through tiny jets so that one stream fully encloses the other. As the jet stream breaks up, droplets form and are hardened into capsules just 50 nanometers wide. At this size, nutrient-bearing capsules could circulate in the blood and enter human cells. What's more, by using different materials for the outer shells, scientists can cause the bubbles to pop open at will when exposed to microwaves or excited with ultrasound.
Improved delivery of food additives and drugs is just one implication of this discovery, which is described in the Mar. 1 issue of Science. By pairing different types of fillings with different outer shells, researchers should be able to fine-tune where and when edible capsules would be digested. "You can design a nutrient that will be absorbed several times more efficiently" than traditional food additives, says Marquez. You could even control the release of flavors or aromas.
The bubbles are also being considered for uses beyond the medicine chest or the dinner plate. One of Marquez' teammates is conjuring up tiny, oil-coated water drops as a fuel for space ships.
By Julie Forster
Recycling Water--by Storing It Underground
Water emergencies in parts of the Northeast have sparked worries of a larger drought in the U.S. Now, researchers in arid Australia have come up with a way to help--an efficient, low-tech method to use the earth's own subterranean water tanks to store and clean tainted water during wet periods and reuse it when the rains stop. "By recycling water we're throwing away, we can take pressure off of freshwater sources" says Simon Toze, a Perth-based scientist with the Commonwealth Scientific & Industrial Research Organisation.
Toze and his CSIRO cohorts have reported that polluted urban rainwater--and even lightly treated sewage--can be collected and mechanically pumped underground into existing aquifers. Right away, this saves water that might otherwise evaporate or flow to the sea. It also turns out that underground storage naturally kills some disease-causing organisms, making the water clean enough for some uses on farms. In as little as six weeks, the CSIRO researchers found, hostile subterranean conditions--a lack of oxygen and nutrients, temperature fluctuations, and competition from indigenous ground-dwelling microorganisms--neutralized surface-borne infectious viral agents and bacteria such as Salmonella. While the water isn't safe enough to drink, it can be used for irrigation of farms and for gardens.
Storing water underground also avoids the habitat destruction caused by traditional above-ground dams. There are currently four aquifer storage test sites in Australia, with similar programs in the works in the U.S. and Europe.
By Darnell Little
An Off Switch for Inflammation
Inflammation plays a key role in a broad range of diseases, including asthma, Alzheimer's, diabetes, cancer, and heart disease. Although inflammation is a normal biological response to infection or injury, the process can go haywire, accelerating until it damages organs.
Vasogen of Toronto has developed a therapy aimed at inducing the patient's own immune system to put the brakes on inflammation. A sample of the patient's blood is removed and placed in a special container where chemicals artificially age the cells. One role of the immune system is to constantly purge old cells, so when the altered blood is reinjected into the patient it triggers the release of immune proteins that also shut off out-of-control inflammation.
In February, Vasogen reported that its immune-modulation therapy significantly reduced hospitalizations and deaths in a clinical trial of 73 patients with congestive heart failure. The process also is being tested against peripheral arterial disease, caused when plaque clogs the arteries and sets off inflammation.
By Catherine Arnst
A Lick of Paint to Keep the Germs Away
Thanks to modern science, you can now protect yourself against deadly microbes--and redecorate at the same time. In March, the Environmental Protection Agency approved a surface coating--i.e., paint--called Caliwel that kills more than 20 harmful microbes, including the bugs that cause hepatitis,
Legionnaire's disease, and cholera. According to its manufacturer, Alistagen of New York, Caliwel kills microbes on contact within five to 15 minutes and keeps on killing for up to six years.
The coating's secret weapon is calcium hydroxide, a germ-fighting powder. Because the compound quickly becomes ineffective when exposed to air, Alistagen has concentrated it in microcapsules able to resist degradation.
The coating is now available in one- and five-gallon containers, costing $69 and $295, respectively. It may not be cheap, but at least you won't be stuck with institutional gray. Caliwel comes in seven colors, with custom mixes available on request.
By Catherine Arnst
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Copyright 2002 , by The McGraw-Hill Companies Inc. All rights reserved.
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