Nanotechnologists work at the level of individual atoms and molecules, either
to create new materials with astonishing properties, or to build miniscule
machines. Some of these tiny new machines may be biomedical devices that could
deliver drugs to precise targets inside your body, or carry out internal repairs
on the spot.
Right now, prototypes of these miracle machines exist. Some are made of natural
molecules; others are hybrids of molecules and artificial parts.
Real-life Fantastic Voyages
In Isaac Asimov’s science fiction classic, The
Fantastic Voyage, scientists shrink themselves to travel in a minute
submarine through an ailing colleague’s blood stream to repair his heart.
Some nanotechnologists are trying to build that little sub, and to send it
through the human body on its own, to deliver drugs or to make repairs.
Nature’s own clean, efficient, molecule-sized motors are already at work
throughout living systems, where they deliver energy and information to cells.
Some researchers are excited by the possibility of harnessing natural molecular
motors that are responsible for most forms of movement at the cellular level.
At the Purdue Cancer
Center, molecular virologist Peixuan
Guo, has made the most
powerful nanoscale motor to date, from completely natural parts: viral
RNA and DNA. The motor runs on natural chemical fuel. Guo and his research
team have already driven the motor inside a cell to destroy
hepatitis virus.
Peixuan Guo's nanomotor. image: Peixuan Guo, Purdue University
At UCLA, biomedical engineer Carlo
Montemagno is building nanodevices from natural molecules and manmade
parts. He calls them "bio bots." Montemagno is chair of the Department
of Bioengineering and co-director of the Institute
for Cell Mimetic Space Exploration, which is developing tiny spacecraft
inspired by nature, to make space exploration easier in the future. Like Guo’s
biomotor, Montemagno’s biobots allow him to biopower to tiny plastic
or metal parts. “In living systems, molecules perform repetitive functions
the way machines do,” Montemagno explains. “Some molecules take
matter or information and move it from one location to another. There are
other molecules which filter, which pump. I look at how to take pieces of
these molecular machines and engineer them into hybrid devices. That means
devices that are living and non-living, that incorporate all the functionality
you find in living systems, but are artificial and engineered.”
Peixuan Guo's nanomotor. image: Peixuan Guo, Purdue University
At UCLA, biomedical engineer Carlo
Montemagno is building nanodevices from natural molecules and manmade
parts. He calls them "bio bots." Montemagno is chair of the Department
of Bioengineering and co-director of the Institute
for Cell Mimetic Space Exploration, which is developing tiny spacecraft
inspired by nature, to make space exploration easier in the future. Like Guo’s
biomotor, Montemagno’s biobots allow him to biopower to tiny plastic
or metal parts. “In living systems, molecules perform repetitive functions
the way machines do,” Montemagno explains. “Some molecules take
matter or information and move it from one location to another. There are
other molecules which filter, which pump. I look at how to take pieces of
these molecular machines and engineer them into hybrid devices. That means
devices that are living and non-living, that incorporate all the functionality
you find in living systems, but are artificial and engineered.”
Montemagno came to UCLA from Cornell, where he developed a “nanocopter,”
a biomotor the size of a virus with a minute nickel propeller mounted on an
even tinier nickel post. The biocomponent converts the body’s chemical
fuel, ATP,
into energy to turn the propellers and drive the motor. Although Montemagno
envisions his nanocopter being used to deliver or even manufacture drugs in
the human body, it isn’t likely to be available to medicine for at least
a decade.
More recently, at UCLA, Montemagno has been working on nanodevices that regenerate
electric current. They could become “artificial nerve cells” or
even parts of a computer structured like the human brain. Montemagno thinks
these new hybrids could be used as “a bridge for severed nerves, to
act as a jumper cable to start them working again.” They also have the
potential to work as pacemakers. “Instead of having to install a mechanical
pacemaker,” Montemagno says, “you’d install something which
is part biological and part engineered, and which becomes part of the organism.”
At present, Montemagno’s vision of prostheses that “are no longer
something alien” is hampered by the difficulty of manufacturing reliable
devices in large quantities on the nanoscale. Out of his first batch of 400
nanocopters, only
five worked. Right now, he says, perhaps three percent work.
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