| To: Cary Salsberg who wrote (96) | 1/31/1997 10:25:00 AM | | From: Sam Citron | of 117 | | |
Cary,
No blood running yet but I thought you might find this of interest:
January 31, 1997
Researchers Create Membrane
To Link Chips to Living Cells
By DEAN TAKAHASHI
Staff Reporter of THE WALL STREET JOURNAL
Jay Groves wants to make it clear that there are limits to
his laboratory breakthrough. "Our goal," he says
emphatically, "is not to stick a chip in your brain."
His disclaimer says a lot about the implications of a
discovery on the far frontiers of computer science and
chemistry: a way to attach a living cell to a computer chip
via a microscopic membrane.
The journal Science has the full text of the research by
Jay Groves, Steven Boxer and Nick Ulman on its Web
site at
sciencemag.org 
So-called biochips have been a staple of science fiction
for years. William Gibson, author of the 1984 cyberpunk
novel "Neuromancer," envisioned chips that could be
plugged into someone's brain so that they could
instantaneously catch up on their history or literature.
But in real life, living cell membranes are notoriously
slippery, amorphous things that can't be connected to the
surface of a solid silicon chip. So three Stanford
University researchers -- Mr. Groves, a graduate student,
chemistry professor Steven Boxer and
electrical-engineering researcher Nick Ulman -- have
created a synthetic cell membrane to serve as a layer
between chip and cell. Minute electrical fields help the
silicon chip adhere to one side of the membrane, while a
living cell sticks to the other side of the membrane.
"The synthetic membrane fools the living cell into thinking
[it's touching] another living cell," said Dr. Boxer, who
teaches at the university in Palo Alto, Calif. "So the living
cell will go ahead and attach itself."
The researchers, no fans of science fiction, say they can't
yet see the day when a "Six Million Dollar Man" starts
flexing bionic muscles. Indeed, they are far from
perfecting the tools that would allow cells and chips to
"speak" to each other across the synthetic membrane.
But their work does offer some more-realistic
possibilities. For example, doctors looking for leukemia
cells in blood could pour a blood sample over a chip with
a patchwork of membranes and get their answer within
seconds, as the cells in the blood were automatically
sorted and identified. Since millions of cells could fit on
the surface of a thumbnail-size chip, theoretically, millions
of tests could be done simultaneously.
Other independent researchers who have reviewed the
Stanford process speculate that it could allow drug
companies to perform, say, 10,000 blood tests for AIDS
in the time it currently takes to do one, measuring changes
in light or electrical forces. Another idea is to test new
drugs on living cells, with the chip assessing the drug's
effects on the cells.
News of the Stanford research, which will be detailed in
an article appearing in the journal Science Friday, has
excited some researchers who ponder the "man-machine
interface." Wentai Liu, a professor of electrical
engineering at North Carolina State University in Raleigh,
N.C., has helped eye specialists at Johns Hopkins
University create chips with light sensors that can help
blind patients detect shades of light. When inserted in the
eye near the optic nerve, his chips send an electric signal
over the tiny space between nerve and chip. A direct link
between cell and chip could make the communication
more precise.
Dr. Liu considers the cell-membrane research a
significant step forward in the science of bionics, or
putting humans and machines together. "It's an elegant
solution that could prove useful in our work," Dr. Liu
said.
The Stanford team's techniques "certainly offer a more
stable way of attaching chips with hard surfaces to gunky
biological cells," said Eric Drexler, a researcher at Palo
Alto-based Foresight Institute who has long sought ways
to develop tools to manipulate molecules and atoms, a
science called "nanotechnology."
The Stanford research project, which is Mr. Groves'
doctoral thesis, took several years of trial-and-error and
false starts. Mr. Groves is a 26-year-old graduate student
who has to brush aside long brown hair to look into a
microscope. He experimented with samples of lipid
molecules, which are common to all living beings and are
easily pulled out of cells. In his experiments, he
repeatedly scratched deep cuts into samples of the
membrane with tweezers, watching the way it flowed into
structures resembling cell walls.
The researchers then found that a synthetic cell
membrane would attach itself to silicon chip surfaces --
but wouldn't stick to other materials used on chips, such
as aluminum compounds. Thus, by controlling the
patterns of aluminum compounds placed on the surface of
a silicon chip, the researchers could dictate where the
membranes' molecules gathered on the chip, even if the
sections were each a hundred times smaller than a hair's
width.
The scientists envision chips with sensitivity to light or
electrical charges that would analyze the cells attached to
the membranes. For instance, a cell might trigger a
change in electrical charge that a chip could detect; the
chip would then communicate the exact location of the
cell to a computer. Researchers could use such a chip to
perform experiments on individual cells.
Tools like these, says Dr. Drexler, the Foresight Institute
researcher, will ultimately pay off in bionics applications,
like replacing damaged neural connections with chips that
conduct signals directly to the brain. Dr. Boxer, however,
is more circumspect.
"We're not interested in fantasy," he said. "We're
practical and we try to make things work on the physical
level, not the hypothetical." |
| | Semi-equips - Buy when BLOOD runs, then find a new sector! | Stock Discussion ForumsShare | Recommend | Keep | Reply | Mark as Last Read |
|
