Straight from the lab: technology’s first draft

Oct 1, 2003

Buckyball Antibiotics

Soccer-ball-shaped molecules called buckyballs, or fullerenes, could soon help antibiotics find their goals. Lon Wilson, a chemist at Rice University, has fabricated an antibiotic-fullerene complex that’s able to target specific tissues; this new type of molecule opens the possibility of treating infections with far greater efficiency than is possible with conventional drugs.

To treat the bacterial bone infections that occur in a small percentage of patients who undergo orthopedic surgery, for example, Wilson attached two molecules of a potent antibiotic called vancomycin to a fullerene molecule. Then, at a different site on the buckyball, he attached another chemical, which binds only to bone. Because the treatment, which was developed in collaboration with an orthopedic surgeon at Beth Israel Hospital in New York City, precisely targets just the tissue that’s affected by the bacteria, patients wouldn’t need as large a dose of the antibiotic to treat their infections. Wilson hopes to test the new antibiotic in animals in the next year. He is also working on buckyball versions of the antibiotic Cipro for treating anthrax infections. Such drugs could latch on to anthrax spores in the lungs and destroy the pathogen before it releases its toxin.

Mind Reader

Many disorders of learning, memory, and motor control are caused by abnormal amounts of glutamate, a neurotransmitter in the brain. If glutamate concentrations could be accurately monitored, surgeons could find and remove cells that poorly regulate glutamate levels. So a team led by University of Kentucky neurobiologist Greg Gerhardt has developed microsensors that track the concentration of glutamate quickly enough-and in enough locations simultaneously-to aid in such surgeries. Each sensor consists of at least two recording patches of platinum, coated with an enzyme and polymers, on the end of a ceramic probe five micrometers wide. The coating reacts with the glutamate, creating an electric current proportional to the glutamate concentration. The sensors work on a second-by-second basis, unlike existing devices that take tens of seconds to register changes, says Gerhardt. Placed in an epileptic patient’s brain for the duration of surgery, a 60-micrometer-by-700-micrometer array of the sensors could pinpoint the smallest region of tissue that needs to be removed. Gerhardt plans to mass-produce the sensors in about two years at his company, Quanteon, in Lexington, KY.

Calmer Skies

In-flight turbulence is hard to predict and the leading cause of injuries on airplanes. Researchers at the National Center for Atmospheric Research in Boulder, CO, have developed software to improve turbulence prediction. When flying through storms, pilots use onboard Doppler radars to scout for drier areas, assuming that these will be calmer. But turbulence can still strike. Algorithms in the new software reduce noise in the radar data; warning algorithms then analyze the data to find the amount of movement in the tiny bits of water and ice found even in “dry” areas. The wider the spectrum of velocities among the droplets, the more likely an encounter with turbulence. In flights on a NASA test plane, the software detected about 80 percent of turbulence with at least a minute’s warning-enough time to seat passengers and flight attendants and clear aisles.

Shoe Sensing

Most airline passengers agree that few things are more annoying than removing their shoes for security x-rays, but researchers might have found a way to speed the footwear check. MIT electrical engineer Markus Zahn and research assistant Jason Sears are developing a shoe-bomb detector embedded in a floor pad. When a passenger steps onto the pad, a series of electrodes generates a low-energy electromagnetic field a few centimeters high that penetrates the soles of the shoes. In less than a second, sensors in the device measure the changes in the field due to the footwear; that “signature” is compared to database-stored signatures for explosives and other dangerous substances. Working with Jentek Sensors in Waltham, MA, the MIT researchers hope to market the technology within two years.

Out of Gas?

Your car’s fuel gauge is on “e.” should you stop for gas, or can you eke out a few more kilometers? You can’t know for sure, because the mechanical floats used in most automobile gas tanks are imprecise. But a cheaper, more durable type of fuel gauge, based on technology used in flat electronic keypads, could tell you exactly, with digital accuracy, how much fuel is in your tank. The pads, based on technology from Wheaton, IL-based TouchSensor Technologies, consist of electrodes mounted behind a plastic plate that create an electric field above the plate. Liquid sloshing over the plate interrupts this field, tripping a switch. Material Sciences, in Elk Grove Village, IL, has licensed the core technology and plans to further develop and market the pads to Detroit automakers, which could embed vertical columns of the devices into the walls of gas, oil, coolant, or windshield wiper fluid tanks; the pads would sense falling fluid levels and transmit precise data to a dashboard display. And because the devices could be placed directly in the walls of plastic tanks as the tanks are molded, they should be cheaper than mechanical-float systems as well.

Temperature Tags

Each year, billions of dollars are wasted in the united states because food, drink, and drugs grow too hot or too cold during transport. Researchers at Infratab in Oxnard, CA, have developed electronic tags that track time and temperature for such perishables as vaccines and meat. Ranging in size from a postage stamp to a credit card, the battery-powered tags are programmed with data on the relationship between temperature and shelf life for specific items. Measuring the temperature every 15 minutes, a tag shows the approach of an item’s expiration date by turning a liquid-crystal display from green to yellow to red. This method is more reliable than conventional date stamps, chemical-based labels, and temperature probes mounted in trucks, says Infratab CEO Terry Myers. And retailers can access the temperature history of any tag by scanning it with a computerized radio frequency reader. Companies that ship meat, beer, and pharmaceuticals are testing the tags, which cost from several cents to several dollars each and should be commercially available within a year.

Gene Repair

Though facing high hurdles, gene therapy remains the best long-term hope for treating many genetic diseases. But for some devastating disorders, such as polycystic kidney disease, simply supplying patients with healthy copies of their disease-causing genes-the traditional approach in gene therapy-may not be enough. Molecular geneticist Al George at Vanderbilt University in Nashville, TN, has demonstrated a type of gene therapy that can repair the damage caused by such diseases. George created a gene that encodes an RNA enzyme that can excise defective portions of mRNA molecules-short templates that translate a gene’s code into a protein-and replace them with the correct sequences. He showed that after injection with the new gene, cells carrying a mutated gene that causes a muscle-wasting disease stopped producing the harmful protein and began producing the normal one. George hopes to improve the process enough to begin animal studies within two years.

Clocking Traffic

It’s quitting time, and you want to know whether traffic conditions will allow you to get home in time for dinner. You could check commuter sites on the Web or listen to the radio-or, as soon as next year, you could glance at the “traffic meter” on your desk. Under development by Ambient Devices in Cambridge, MA, the meter features a dial that might point to “30 minutes” if traffic is light and “90 minutes” if there’s a pileup. The meter uses an internal pagerlike device to get updates every few minutes from a computer at Ambient, which both stores a description of your route home and calculates drive time using real-time data from national traffic information systems. The meter is one of a series of “glanceable devices” planned by the company. “We are trying to make all kinds of information as easy to know as time,” says Ben Resner, Ambient’s cofounder and vice president of technology.