Studeo
24th June 2010, 04:54
Public release date: 21-Jun-2010
http://www.eurekalert.org/pub_releases/2010-06/hms-rcs062110.php
Researchers create self-assembling nanodevices that move and change
shape on demand
BOSTON, Mass. (June 20, 2010) – By emulating nature's design
principles, a team at Harvard's Wyss Institute for Biologically
Inspired Engineering, Harvard Medical School and Dana-Farber Cancer
Institute has created nanodevices made of DNA that self-assemble and
can be programmed to move and change shape on demand. In contrast to
existing nanotechnologies, these programmable nanodevices are highly
suitable for medical applications because DNA is both biocompatible
and biodegradable.
The work appears in the June 20 advance online Nature Nanotechnology.
Built at the scale of one billionth of a meter, each device is made of
a circular, single-stranded DNA molecule that, once it has been mixed
together with many short pieces of complementary DNA, self-assembles
into a predetermined 3D structure. Double helices fold up into larger,
rigid linear struts that connect by intervening single-stranded DNA.
These single strands of DNA pull the struts up into a 3D form—much
like tethers pull tent poles up to form a tent. The structure's
strength and stability result from the way it distributes and balances
the counteracting forces of tension and compression.
This architectural principle—known as tensegrity—has been the focus of
artists and architects for many years, but it also exists throughout
nature. In the human body, for example, bones serve as compression
struts, with muscles, tendons and ligaments acting as tension bearers
that enable us to stand up against gravity. The same principle governs
how cells control their shape at the microscale.
"This new self-assembly based nanofabrication technology could lead to
nanoscale medical devices and drug delivery systems, such as virus
mimics that introduce drugs directly into diseased cells," said
co-investigator and Wyss Institute director Don Ingber. A nanodevice
that can spring open in response to a chemical or mechanical signal
could ensure that drugs not only arrive at the intended target but are
also released when and where desired.
Further, nanoscopic tensegrity devices could one day reprogram human
stem cells to regenerate injured organs. Stem cells respond
differently depending on the forces around them. For instance, a stiff
extracellular matrix—the biological glue surrounding cells—fabricated
to mimic the consistency of bone signals stem cells to become bone,
while a soupy matrix closer to the consistency of brain tissue signals
the growth of neurons. Tensegrity nanodevices "might help us to tune
and change the stiffness of extracellular matrices in tissue
engineering someday," said first author Tim Liedl, who is now a
professor at Ludwig-Maximilians-Universität in Munich.
"These little Swiss Army knives can help us make all kinds of things
that could be useful for advanced drug delivery and regenerative
medicine," said lead investigator William Shih, Wyss core faculty
member and associate professor of biological chemistry and molecular
pharmacology at HMS and Dana-Farber Cancer Institute. "We also have a
handy biological DNA Xerox machine that nature evolved for us," making
these devices easy to manufacture.
This new capability "is a welcome element in the structural DNA
nanotechnology toolbox," said Ned Seeman, professor of chemistry at
New York University.
###
This research was funded by the Wyss Institute for Biologically
Inspired Engineering at Harvard University, National Institutes of
Health, Deutscher Akademischer Austauschdienst Fellowship, Swedish
Science Council Fellowship and Claudia Adams Barr Program Investigator
award.
Written by Elizabeth Dougherty
Citation:
Nature Nanotechnology, online publication, June 20, 2010
"Self-assembly of 3D prestressed tensegrity structures from DNA"
Tim Liedl, Bjorn Hogberg, Jessica Tytell, Donald E. Ingber, William M. Shih
http://www.eurekalert.org/pub_releases/2010-06/hms-rcs062110.php
Researchers create self-assembling nanodevices that move and change
shape on demand
BOSTON, Mass. (June 20, 2010) – By emulating nature's design
principles, a team at Harvard's Wyss Institute for Biologically
Inspired Engineering, Harvard Medical School and Dana-Farber Cancer
Institute has created nanodevices made of DNA that self-assemble and
can be programmed to move and change shape on demand. In contrast to
existing nanotechnologies, these programmable nanodevices are highly
suitable for medical applications because DNA is both biocompatible
and biodegradable.
The work appears in the June 20 advance online Nature Nanotechnology.
Built at the scale of one billionth of a meter, each device is made of
a circular, single-stranded DNA molecule that, once it has been mixed
together with many short pieces of complementary DNA, self-assembles
into a predetermined 3D structure. Double helices fold up into larger,
rigid linear struts that connect by intervening single-stranded DNA.
These single strands of DNA pull the struts up into a 3D form—much
like tethers pull tent poles up to form a tent. The structure's
strength and stability result from the way it distributes and balances
the counteracting forces of tension and compression.
This architectural principle—known as tensegrity—has been the focus of
artists and architects for many years, but it also exists throughout
nature. In the human body, for example, bones serve as compression
struts, with muscles, tendons and ligaments acting as tension bearers
that enable us to stand up against gravity. The same principle governs
how cells control their shape at the microscale.
"This new self-assembly based nanofabrication technology could lead to
nanoscale medical devices and drug delivery systems, such as virus
mimics that introduce drugs directly into diseased cells," said
co-investigator and Wyss Institute director Don Ingber. A nanodevice
that can spring open in response to a chemical or mechanical signal
could ensure that drugs not only arrive at the intended target but are
also released when and where desired.
Further, nanoscopic tensegrity devices could one day reprogram human
stem cells to regenerate injured organs. Stem cells respond
differently depending on the forces around them. For instance, a stiff
extracellular matrix—the biological glue surrounding cells—fabricated
to mimic the consistency of bone signals stem cells to become bone,
while a soupy matrix closer to the consistency of brain tissue signals
the growth of neurons. Tensegrity nanodevices "might help us to tune
and change the stiffness of extracellular matrices in tissue
engineering someday," said first author Tim Liedl, who is now a
professor at Ludwig-Maximilians-Universität in Munich.
"These little Swiss Army knives can help us make all kinds of things
that could be useful for advanced drug delivery and regenerative
medicine," said lead investigator William Shih, Wyss core faculty
member and associate professor of biological chemistry and molecular
pharmacology at HMS and Dana-Farber Cancer Institute. "We also have a
handy biological DNA Xerox machine that nature evolved for us," making
these devices easy to manufacture.
This new capability "is a welcome element in the structural DNA
nanotechnology toolbox," said Ned Seeman, professor of chemistry at
New York University.
###
This research was funded by the Wyss Institute for Biologically
Inspired Engineering at Harvard University, National Institutes of
Health, Deutscher Akademischer Austauschdienst Fellowship, Swedish
Science Council Fellowship and Claudia Adams Barr Program Investigator
award.
Written by Elizabeth Dougherty
Citation:
Nature Nanotechnology, online publication, June 20, 2010
"Self-assembly of 3D prestressed tensegrity structures from DNA"
Tim Liedl, Bjorn Hogberg, Jessica Tytell, Donald E. Ingber, William M. Shih