Wednesday, July 9, 2008 | Having already established itself as a hub for the burgeoning field of biotechnology, San Diego is now poised to become a prime player in the growing global market of nanotechnology — the emerging body of small-scale science that researchers predict will revolutionize the medical world.
Nanotechnology can be thought of as customized science. Researchers essentially tinker with and rearrange molecules and atoms to create new materials or devices with specific purposes. The science is all done on the tiny scale of nanometers, or billionths of a meter, because some familiar objects behave differently when they’re miniaturized.
For example, in bulk, gold is a good conductor of heat and electricity. Nanoparticles of gold, on the other hand, can be structured to absorb light and turn it into heat. The heat created by the tiny morsels of gold can perform like a miniature thermal scalpel, able to kill cancer cells in the body.
Cut strips of aluminum small enough it requires a microscope to see them and the pieces can explode, leading some researchers to consider adding nano-aluminium to rocket fuel.
Researchers at the University of California, San Diego, Moores Cancer Center are developing molecule-sized bits, technically called nanoparticles, to target specific cancer cells while avoiding healthy ones. Unlike conventional chemotherapy, the treatment could leave healthy tissue unscathed because the minute particles will carry a small molecule that can attach itself, and its drug dose, only to blood vessels that feed the tumors.
In another laboratory at UCSD, chemist Michael Sailor and a diverse team of researchers used nanotechnology to develop “smart dust,” silicon flakes that can detect chemicals and biological toxins in the air.
The researchers were developing small chemical sensors from silicon wafers — the element computer chips are made from — and scientists became frustrated by tiny flakes that kept chipping off.
But then, one of the researchers became intrigued with the glittery flakes and realized that they could be engineered to reflect different colors of light when exposed to particular chemicals, such as a pollutant, toxin or explosive — a boon for agencies needing an advantage in the field of biological warfare. They dubbed the flakes, which turn from red to green when they encounter the chemical they have been engineered to find, smart dust. The technology is under development by a private company and is expected to be market-ready within two years.
Substances behave uniquely at the nanoscale because that’s where the essential properties of matter are determined. Arrange calcium carbonate molecules in a jagged pattern, for instance, and you get crumbly chalk. Stack the same molecules like tiles, and they help form the layers of the tough shell of an abalone.
Sailor, who is also involved in other nanotechnology research, compared the science to the invention of plastic, which transformed everything from kitchen appliances and food containers to housing construction and medical safety.
“It’s going to be everywhere,” he said. “It’ll be in all the clothes we wear, make-up we use, even the air we breathe.”
While nanotechnology is promising in the medical field because it has given rise to devices with the ability to move easily through the body and interact with specific cells, it has also triggered fears, some more realistic than others, about unintended consequences and new hazards.
It’s possible that some particles manufactured at such tiny scales could prove harmful to human health if handled improperly. If inhaled, the tiny slivers of particles can move fast and deeply penetrate and clog the lungs, heart and other body parts.
“We’re dealing with [particles] so small they can pass through the membranes of cells,” Sailor said. “There are potential hazards people have to assess before subjecting the public to something.”
Other fears are more hype than reality. One of best examples of the worst-case scenarios people fear can be found on the pages of Michael Crichton’s 2002 novel “Prey.” The book is the tale of unchecked nanotechnology and irresponsible science as self-replicating “nano-machines” multiply uncontrollably and overwhelm the human race.
“It’s a clever and novel concept,” Sailor said of the fiction. “It’s a bit far-fetched and we’re certainly not at that stage yet. But it’s a cautionary tale.”
Still, nanotechnology has become a booming industry. Researchers and scientists at an international biotechnology conference held in San Diego last month predicted that in less than a decade, at least half of all new products will stem from nanotechnology. The National Science Foundation estimates that the nanotechnology market will be worth a trillion dollars by 2015. Along with San Diego, other up-and-coming regions include the San Francisco Bay area and Boston. Abroad, Asian and European companies are also scrambling to get a piece of the economic action, according to the foundation.
Hundreds of products on store shelves, including stain-resistant clothing, advanced microchips and clear sunscreens, already incorporate the technology. Nanopants, available at the Gap, are made from fibers treated with a customized nanopolymer. If liquid is spilled on them, it rolls right off without being absorbed. Carbon nanotubes have a light, yet stiff composition and have been used to strengthen tennis rackets, bicycle handlebars and golf-club shafts.