Big Science, Small Miracles


By George Alexander, Illustrations by Josh Dorman

Published Jan 1, 2009 8:05 AM

The Littlest Patients

In October, Mattel Children's Hospital UCLA announced the new Mattel UCLA NanoPediatrics Program, believed to be the world's first nanotechnology program dedicated solely to pediatric patients. Edward R.B. McCabe, famed UCLA pediatric physician, professor of genetics and bioengineering, and physician-in-chief, is using nanodiagnostics to develop the screening of newborn children at risk for obesity, cancer or other diseases and illnesses later in life.

Using a commercial nanodiagnostic machine, McCabe takes a small tissue or blood sample from the patient, isolates the DNA and breaks it up into very small segments. These nanoscale pieces are tagged with fluorescent markers and flowed across the machine's nanoscale array of 900,000 DNA sequences known to be linked to different diseases.

"What we're working on," says McCabe, "is a way to say this baby is someday going to be at risk for obesity, or asthma, or any one of a number of diseases, including cancer." Knowing that propensity could lead to treatment or management strategies to prevent or lessen the child's chances of succumbing to his/her otherwise genetic fate.

Cancer Killers

One strategy for dealing with diseases such as cancer that is being actively pursued at many research institutions around the world, including UCLA, is nanoscale drug delivery systems.

Professors Jeffrey Zink, a chemist/biochemist, and Fuyu Tamanoi, a microbiologist/immunologist/molecular geneticist, are co-directors of CNSI's Nano Machine Center for Targeted Delivery and On-Demand Release; they are experimenting with a nanomachine that might be likened to a Trojan Horse. The horse, in this case, is a tiny machine made of mesoporous silica, its pore interiors coated with a compound that responds to light by moving in a back-and-forth motion.

In in vitro experiments, Zink and Tamanoi have let colon and pancreatic cancer cells take up the nanoparticles and then shone a light on them, causing them to move just enough to expel their lethal contents from the silica pores into the tumor cells. Zink and Tamanoi are now focused on steering these tiny Trojan Horses unerringly to tumor cells, in vivo, with just the right lethal dosage to do their disease-fighting job.

Fuel Feeder

In a potential energy application, Omar Yaghi, a professor of chemistry, biochemistry and inorganic chemistry, is exploring uses for tiny particles that his lab discovered, called metal-organic frameworks (MOFs). These molecules offer very large internal surfaces — one gram of an experimental zinc compound, he says, has the areal extent of 40 tennis courts — to hold very large quantities of hydrogen or compressed natural gas, two fuels often described as the eventual replacements for gasoline and oil.

A 1-liter container, its interior filled with these zinc-oxide MOFs, can hold twice as much hydrogen as an identical 1-liter bottle minus the nanoparticles, Yaghi says. Substitute compressed natural gas for hydrogen, and that same 1-liter container could hold enough fuel to double the range of a city bus. Like Zink and Tamanoi, however, Yaghi also has hurdles to overcome: how to move the hydrogen into and out of the MOFs easily, at ambient temperatures.

Water Cleaner

Another UCLA professor, Eric Hoek M.S. '96, is concerned with environmental issues — specifically, water treatment. Dirty, polluted water is an obvious target for treatment, but even the cleanest-looking mountain stream can be carrying harmful bacteria or particles, toxic chemicals and other impurities. And seawater, of course, contains salt, which renders it undrinkable.

Hoek is embedding polymer membranes with nanoparticles to make seawater potable in a way that is more energy-efficient and, therefore, less expensive. His nanocomposite membranes block salts, bacteria and other harmful elements, while allowing H2O molecules to be pumped through rapidly and with less energy input than other membranes.

While the nanoparticles that Hoek uses are non-toxic and inert, he is concerned about potential workplace and environmental hazards. He is working with other scientists and engineers to understand at a more basic level the potential toxicity of other nanomaterials, such as metal and metal oxides, and carbon nanotubes.

"We have to be certain we understand the physical and chemical properties [of these materials]," Hoek explains.

The Large, Looming Question of Nanoethics

To address this and other environmental questions of this promising new field, the National Science Foundation last September granted $24 million to UCLA and 12 collaborating institutions in the U.S., Europe and Asia to establish a Center for Environmental Implications of Nanotechnology.

"We are deeply committed to ensuring that nanotechnology is introduced and implemented in a responsible and environmentally compatible manner," explains Dr. André E. Nel, chief of UCLA's Nanomedicine Division and the director of this new organization.

Caution is an appropriate position to take with this new technology, notes UCLA Law School Professor Timothy F. Malloy, co-director of the Frank G. Wells Environmental Law Clinic. "We're in the earliest evolutionary stages of this field, still at the elementary science level," he says, "so we still have time to consider its societal, ethical and legal implications."

Noting that there are bills now moving through Congress that bear on the health and environmental impacts of nanotechnology, Malloy adds: "If we regulate too precipitously and too heavily, we might very well impede the progress of this promising new field. Too slowly, too lightly, and we might regret not having taken more effective measures."

The ethics of nanotechnology go beyond green issues, of course. A recent National Science Foundation survey identified five public concerns of this new field: privacy violations, through monitoring devices too small to be noticed by the spied-upon; new and insidious weapons; human ingestion, with deleterious and possibly irreversible effects; economic disruptions; and self-replicating, uncontrollable nanobots — the Big Bad in Michael Crichton's creepy 2002 thriller, Prey.

Still, that same survey found that people expect medical advances will be the greatest near-term benefit to come from nanotechnology, followed closely by environmental remediation, security and national defense, enhanced human physical and intellectual capabilities and, bringing up the rear, inexpensive, long-lasting consumer goods.

Whatever tomorrow brings, nanotechnology may be bringing it to us. Will the disruptive technology ever reach the amazing scenario we described at the beginning of our fantastic voyage? "Yes and no," concludes UCLA's Tolbert. "Nanoscale materials are doing amazing things — but Michael Crichton is never going to be a reality."