Corporate Banner
Satellite Banner
RNAi
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Organic Metamaterial Flows like a Liquid, Remembers its Shape

Published: Tuesday, December 04, 2012
Last Updated: Tuesday, December 04, 2012
Bookmark and Share
A bit reminiscent of the Terminator T-1000, a new material created by Cornell researchers is so soft that it can flow like a liquid and then, strangely, return to its original shape.

Rather than liquid metal, it is a hydrogel, a mesh of organic molecules with many small empty spaces that can absorb water like a sponge. It qualifies as a "metamaterial" with properties not found in nature and may be the first organic metamaterial with mechanical meta-properties.

Hydrogels have already been considered for use in drug delivery -- the spaces can be filled with drugs that release slowly as the gel biodegrades -- and as frameworks for tissue rebuilding. The ability to form a gel into a desired shape further expands the possibilities. For example, a drug-infused gel could be formed to exactly fit the space inside a wound.

Dan Luo, professor of biological and environmental engineering, and colleagues describe their creation in the Dec. 2 issue of the journal Nature Nanotechnology.

The new hydrogel is made of synthetic DNA. In addition to being the stuff genes are made of, DNA can serve as a building block for self-assembling materials. Single strands of DNA will lock onto other single stands that have complementary coding, like tiny organic Legos. By synthesizing DNA with carefully arranged complementary sections Luo's research team previously created short stands that link into shapes such as crosses or Y's, which in turn join at the ends to form meshlike structures to form the first successful all-DNA hydrogel. Trying a new approach, they mixed synthetic DNA with enzymes that cause DNA to self-replicate and to extend itself into long chains, to make a hydrogel without DNA linkages.

"During this process they entangle, and the entanglement produces a 3-D network," Luo explained. But the result was not what they expected: The hydrogel they made flows like a liquid, but when placed in water returns to the shape of the container in which it was formed.

"This was not by design," Luo said.

Examination under an electron microscope shows that the material is made up of a mass of tiny spherical "bird's nests" of tangled DNA, about 1 micron (millionth of a meter) in diameter, further entangled to one another by longer DNA chains. It behaves something like a mass of rubber bands glued together: It has an inherent shape, but can be stretched and deformed.

Exactly how this works is "still being investigated," the researchers said, but they theorize that the elastic forces holding the shape are so weak that a combination of surface tension and gravity overcomes them; the gel just sags into a loose blob. But when it is immersed in water, surface tension is nearly zero -- there's water inside and out -- and buoyancy cancels gravity.

To demonstrate the effect, the researchers created hydrogels in molds shaped like the letters D, N and A. Poured out of the molds, the gels became amorphous liquids, but in water they morphed back into the letters. As a possible application, the team created a water-actuated switch. They made a short cylindrical gel infused with metal particles placed in an insulated tube between two electrical contacts. In liquid form the gel reaches both ends of the tube and forms a circuit. When water is added. the gel reverts to its shorter form that will not reach both ends. (The experiment is done with distilled water that does not conduct electricity.)

The DNA used in this work has a random sequence, and only occasional cross-linking was observed, Luo said. By designing the DNA to link in particular ways he hopes to be able to tune the properties of the new hydrogel.


Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,500+ scientific posters on ePosters
  • More than 3,700+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Tumor-suppressing Gene Lends Insight to Cancer Treatment
Researchers have found that delicate replication process derails if a gene named PTEN has mutated or is absent.
Tuesday, July 14, 2015
Computer Model Reveals Cancer's Energy Source
Findings focused on the energy-making process in cancer cells known as the Warburg Effect.
Tuesday, August 19, 2014
For Cancer Patients, Sugar-Coated Cells are Deadly
Paszek’s lab will focus on developing high-resolution microscopy to further study cell membrane-related cancer mechanisms.
Friday, June 27, 2014
Gold-Plated Nano-Bits Find, Destroy Cancer Cells
Scientists have merged tiny gold and iron oxide particles, then added antibody guides to steer them through the bloodstream toward colorectal cancer cells.
Monday, October 21, 2013
Genetic Switches Play Big Role in Human Evolution
Study offers further proof that the divergence of humans from chimpanzees was profoundly influenced by mutations to DNA sequences.
Wednesday, June 12, 2013
Turn out the Light: 'Switch' Determines Cancer Cell Fate
Like picking a career or a movie, cells have to make decisions – and cancer results from cells making wrong decisions.
Friday, May 03, 2013
Nano Compartments May Aid Drug Delivery, Catalyst Design
Spongelike nanoparticles whose pores can be filled with drugs offer the promise of drug delivery to specific targets in the body, avoiding unpleasant side effects.
Monday, April 22, 2013
Scientists Develop World's Smallest Drug Deliverer
Cornell researchers have created a pore in “Cornell Dots” – brightly glowing nanoparticles nicknamed C-Dots – that can carry medicine.
Friday, April 12, 2013
DNA Editor Named Runner-up Breakthrough of 2012
A discovery that allows life scientists to precisely edit genomes for everything from crop and livestock improvement to human gene and cell therapy was named runner-up for Science magazine's 2012 Breakthrough of the Year.
Wednesday, February 27, 2013
Study: How Cells form 'Trash Bags' for Recycling Waste
A class of membrane-sculpting proteins create vesicles that carry old and damaged proteins from the surface of cellular compartments into internal recycling plants where the waste is degraded and components are reused.
Tuesday, October 23, 2012
Metastatic 'Switch' Sheds New Light on Colon Cancer
What kills cancer patients often isn't the primary tumor; it's when the tumor metastasizes - or spreads the cancer to other areas of the body.
Tuesday, September 11, 2012
The Force is with us: GEDI Chip Sorts Prostate Cancer Cells
Geometrically Enhanced Differential Immunocapture chip identify and collect cancer cells from a patient's bloodstream.
Friday, June 29, 2012
Some Stem Cells Can Trigger Tumors
When in contact with even trace amounts of cancer cells, stem cells can create a microenvironment suitable for more tumors to grow.
Wednesday, June 06, 2012
Scientific News
Microscopic Fish are 3D-Printed to do More Than Swim
Researchers demonstrate a novel method to build microscopic robots with complex shapes and functionalities.
Inciting an Immune Attack on Cancer Cells
A new minimally invasive vaccine that combines cancer cells and immune-enhancing factors could be used clinically to launch a destructive attack on tumors.
Reprogramming Cancer Cells
Researchers on Mayo Clinic’s Florida campus have discovered a way to potentially reprogram cancer cells back to normalcy.
New Strategy for Combating Adenoviruses
Using an animal model they developed, Saint Louis University and Utah State university researchers have identified a strategy that could keep a common group of viruses called adenoviruses from replicating and causing sickness in humans.
Surprising Mechanism Behind Antibiotic-Resistant Bacteria Uncovered
Now, scientists at TSRI have discovered that the important human pathogen Staphylococcus aureus, develops resistance to this drug by “switching on” a previously uncharacterized set of genes.
Fat in the Family?
Study could lead to therapeutics that boost metabolism.
Imaging Software Could Speed Up Breast Cancer Diagnosis
Researchers use high speed optical microscopy of intact breast tissue specimens to analyze breast tissue.
A Metabolic Master Switch Underlying Human Obesity
Researchers find pathway that controls metabolism by prompting fat cells to store or burn fat.
Synthetic DNA Vaccine Against MERS Shows Promise
A novel synthetic DNA vaccine can, for the first time, induce protective immunity against the Middle East Respiratory Syndrome (MERS) coronavirus in animal species.
How Small RNA Helps Form Memories
In a new study, a team of scientists at Scripps Florida has found that a type of genetic material called "microRNA" (miRNA) plays surprisingly different roles in the formation of memory in animal models.
SELECTBIO

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!