technology is used in the body, but the complexity of DNA-
based nanomachines is already impressive. Scientists have even
constructed a microscopic alphabet to show their skill in
making DNA form any shape.
“No other material can compete with DNA in terms of
precision and self-assembly,” says Dietz. “It folds into a
precise shape based on the sequence of base pairs we have
programmed. These self-assembly methods are much finer
than what you can do with traditional ‘top-down’ design.”
Other researchers use entire viruses as the basis for their
nanomachines. While viruses are normally thought of as
harmful infectious agents, they can also arguably be seen as
nature’s nanomachines – perfectly evolved to travel deep
into their hosts and inject a genetic payload into cells to
infect them. Biologists are increasingly using non-deadly
viruses to ‘infect’ human cells with new genes in order to
replace those that cause genetic disease. The viruses can be
shielded from the body’s im mune system by alter ing their
outer casing, and – like lab-built nanoparticles – this outer
sur face can be modif ied to ensure they target specif ic cel ls.
The number of potential uses of nanotechnology in
medicine is dizzying. As wel l as tiny devices, scientists havedeveloped gels that self-organise at the nanoscale into
str uctures that can stop bleeding in wounds w ithin seconds.
And a team in South Korea has designed a nanobandage – a
dressing that contains stretchable, wafer-thin
nanotechnology that monitors a patient’s muscle activity or
sk in condition, then adm inisters medication as needed.WHAT NEXT?
This seemingly unending potential has led some to suggest
that nanomedicine could make humans virtually immortal
within a few decades. Renowned futurist Ray Kurzweil
has stated that within the next century he believes DNA-
based ‘nanobots’ will eventually be a routine part of our
blood, scanning each cell in our bodies for damage to
repair.
In the shorter term, researchers like Dietz believe that
integrating biology-based nanotechnology and traditional
engineering could revolutionise the power and efficiency
of technology outside of the body too. “The more
transistors you can pack into a space, then the more
calculations you can do per second,” he says. “A
combination of super-fine, self-assembling DNA PHOTO: ALAMYThe nanobots in
this illustration
look a little like
viruses, which in
themselves can
be used in
nanomedicineSCIENCE