By Richard Acello
Small Times Correspondent
SAN DIEGO, Dec. 10, 2001 — Mike Sailor recalls his first teaching seminar. “I drew a diagram of the heart with the chambers for my sixth grade class,” he remembers. Sailor wasn’t the teacher, but one of the students. “The teacher couldn’t believe it.”
Since then, the University of California, San Diego (UCSD) chemistry professor has emerged as one of the pioneers in the use of nanostructured silicon, shepherding research in a wide range of applications from bioterror detection to next-generation stents for heart patients.
In a way, he’s come full circle since his first lecture on the heart. “It is ironic,” he says.
Research projects in the Sailor Group involve the use of nanocrystalline porous silicon, which is used to coat a chip. When the silicon is exposed to a catalyst, Sailor and his colleagues measure the optical and electrical reactions.
“Mike was one of the people who started the field of working with nanostructured silicon a decade ago,” said William Trogler, a colleague and chemistry professor at UCSD. “Mike’s always trying new ideas left and right.”
His work in developing a network of low-power, battery operated sensors to detect poison gases such as sarin and other bioterror projects funded by the U.S. Defense Advanced Research Project Agency (DARPA) was started before Sept. 11, but has moved into the national spotlight since the terrorist attacks.
With Trogler, Sailor has developed a nanowire composed of silicon polymer that has been tested to detect the presence of TNT down to about one part in a billion in air and about 50 parts per billion in seawater. The polymer could be used as a “sniffer” that would sample the air around a package, for example, or could be dissolved in solvents and painted on surfaces.
But Sailor is most excited about his team’s efforts in using nanophase materials to join the inorganic or “dead” world with biological or living systems.
In an article in the Nov. 30 issue of Cell magazine, Sailor and colleagues Michael Colicos, Boyce Collins, and Yukiko Goda grow nerve cells on silicon wafers and hit them with a beam of light to study how they build connections and form memories.
“Nanomaterials can make a big impact in the life sciences. Take heart transplants,” Sailor says. “To date, they’ve been done with big mechanical machines, but nanotechnology allows you to do things you couldn’t in the past, to make things really small so they can ‘talk’ to capillaries, forming an active matrix that can tell you whether drug interactions, for example, are good or bad.”
Citing early stage research being performed at Cedars-Sinai Hospital in Los Angeles, Sailor says stents like the type inserted into the heart of U.S. Vice President Dick Cheney could be “made smart” to “encapsulate something in the stent so that it senses whether the body is beginning to reject it.”
Sailor is also looking at nanotechnology to regulate drug dosage and to perform tests. “We have to make vessels that hold just a few molecules, so we don’t overdose the patient,” he says. “In testing blood, say there are a thousand assays you want to perform, so you’d either have to take a lot of blood or make it so you just take a small amount question of material. Nanotechnology lets you use smaller and smaller sample amounts so it’s less intrusive.” Or as Sailor delicately put it, “to do a lot of tests without having to burn through a million rats.”
In another Sailor project, nanostructured wells are used to keep liver cells alive. The idea is to “mimic the function of a liver to see if a drug will be toxic. “You can put a lot of functions in a very small space, you can have a lot more information coming out of a single cell,” he explains.
He’s also collaborating with the La Jolla, Calif.-based Burnham Institute on targeted nanomachines that pass into the bloodstream and send reports back from cancer cells. This is key because cancer is more easily cured if caught in early stages. “This research is embryonic — a couple of experiments — but we want to know can we build a machine that works like an antibody or receptor.”
Though science is often thought of as an isolated pursuit, part of Sailor’s success has been his ability to network and attract colleagues, including high school students, to his projects.
“What’s neat about UCSD is that it’s an interdisciplinary community,” he says. “So three years ago I made it a point to go around and ask (biology) people what their problems were.”
“He’s very good at working with undergrads,” says Trogler, “and has more undergrads working for him than most other professors.”
With a dozen or more projects bubbling on various burners, Sailor says he clears his mind by walking or bike riding near the UCSD campus in picturesque La Jolla.
“I want to do something that’s never been done before because that’s the business we’re in — building something that can’t be built by hand,” he says. “It comes down to chemistry, because the human body is built on chemical reactions — how do you build a nose? I want to develop tool sets that nature has not built, but if nature knew it could be built, would want to do it.”
Sailor says he believes the technology will be advanced by the use of optics, using beams of light to induce reactions rather than chemicals. He cites the work quantum dot pioneer Paul Alivisatos of the University of California, Berkeley, and Moungi Bawendi of the Massachusetts Institute of Technology as having fired “shots across the bow.”
With the intersection between biology and inorganic materials, the new century may belong to the nanobiologist,” Sailor says, working with “stuff too small for a surgeon’s fingers.”
Sailor’s mix of friends includes folks in the cognitive sciences and literature. So what does he tell lay people about this work? “I tell them I’m an inorganic material chemist — you know the Pentium computer? We use the same materials to do other things.”
In any event, Sailor says he’s not the least bit fazed by working in the fast moving field of nanotechnology. He quotes Alivisatos as saying, “This stuff is so far out that no one will understand it and by the time they do, it will be over.”
More on Sailor’s Research
Tiny chips could serve as scouts in war and peace
Some anti-terror tools of the future