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

New Injectable Gels Toughen up after Entering the Body

Published: Friday, November 16, 2012
Last Updated: Friday, November 16, 2012
Bookmark and Share
These more durable gels could find applications in drug delivery and tissue engineering.

Gels that can be injected into the body, carrying drugs or cells that regenerate damaged tissue, hold promise for treating many types of disease, including cancer. However, these injectable gels don’t always maintain their solid structure once inside the body.

MIT chemical engineers have now designed an injectable gel that responds to the body’s high temperature by forming a reinforcing network that makes the gel much more durable, allowing it to function over a longer period of time.

The research team, led by Bradley Olsen, an assistant professor of chemical engineering, described the new gels in a recent issue of the journal Advanced Functional Materials. Lead author of the paper is Matthew Glassman, a graduate student in Olsen’s lab. Jacqueline Chan, a former visiting student at MIT, is also an author.

Olsen and his students worked with a family of gels known as shear thinning hydrogels, which have a unique ability to switch between solid-like and liquid-like states. When exposed to mechanical stress — such as being pushed through an injection needle — these gels flow like fluid. But once inside the body, the gels return to their normal solid-like state.

However, a drawback of these materials is that after they are injected into the body, they are still vulnerable to mechanical stresses. If such stresses make them undergo the transition to a liquid-like state again, they can fall apart.

“Shear thinning is inherently not durable,” Olsen says. “How do you undergo a transition from not durable, which is required to be injected, to very durable, which is required for a long, useful implant life?”

The MIT team answered that question by creating a reinforcing network within their gels that is activated only when the gel is heated to body temperature (37 degrees Celsius).

Shear thinning gels can be made with many different materials (including polymers such as polyethylene glycol, or PEG), but Olsen’s lab is focusing on protein hydrogels, which are appealing because they can be designed relatively easily to promote biological functions such as cellular adhesion and cell migration.

The protein hydrogels in this study consist of loosely packed proteins held together by links between protein segments known as coiled coils, which form when two or three helical proteins coil into a ropelike structure.

The MIT researchers designed their hydrogel to include a second reinforcing network, which takes shape when polymers attached to the ends of each protein bind together. At lower temperatures, these polymers are soluble in water, so they float freely in the gel. However, when heated to body temperature, they become insoluble and separate out of the watery solution. This allows them to join together and form a sturdy grid within the gel, making it much more durable.

The researchers found that gels with this reinforcing network were much slower to degrade when exposed to mechanical stress and were significantly stiffer. This offers a promising way to thwart the tendency of shear thinning materials to erode once in the body, says Jason Burdick, an associate professor of bioengineering at the University of Pennsylvania.

“Building in this secondary network based on a different type of mechanism is a very elegant way to overcome that obstacle through material design,” says Burdick, who was not part of the research team.

Another advantage of these gels is that they can be tuned to degrade over time, which would be useful for long-term drug release. The researchers are now working on ways to control this feature, as well as incorporating different types of biological functions into the gels.

The research was funded by the U.S. Army Research Office through MIT's Institute for Soldier Nanotechnologies (ISN). Potential applications of these nanostructured gels to soldier medicine include preventing blood loss, accelerating wound healing and protecting against infections and disease.

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 2,800+ scientific posters on ePosters
  • More than 4,000+ 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 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

A Natural Light Switch
MIT scientists identify and map the protein behind a light-sensing mechanism.
Tuesday, September 29, 2015
Biologists Find Unexpected Role for Amyloid-Forming Protein
Yeast protein could offer clues to how Alzheimer’s plaques form in the brain.
Monday, September 28, 2015
How Flu Viruses Gain The Ability To Spread
New study reveals the soft palate is a key site for evolution of airborne transmissibility.
Friday, September 25, 2015
Targeting DNA
Protein-based sensor could detect viral infection or kill cancer cells.
Tuesday, September 22, 2015
Targeting DNA
Protein-based sensor could detect viral infection or kill cancer cells.
Tuesday, September 22, 2015
Learning About Human Health Using Sewage
PhD student Mariana Matus studies human waste to understand individual and community health.
Thursday, September 17, 2015
Protein Found to Play a Key Role in Blocking Pathogen Survival
Calprotectin fends off microbial invaders by limiting access to iron, an important nutrient.
Wednesday, August 26, 2015
Real-Time Data for Cancer Therapy
Biochemical sensor implanted at initial biopsy could allow doctors to better monitor and adjust cancer treatments.
Thursday, August 06, 2015
Bacterial Computing
The “friendly” bacteria inside our digestive systems are being given an upgrade, which may one day allow them to be programmed to detect and ultimately treat diseases such as colon cancer and immune disorders.
Monday, July 13, 2015
New Approach to Global Health Challenges
MIT’s Institute for Medical Engineering and Science brings many tools to the quest for new disease treatments and diagnostic devices.
Friday, September 27, 2013
Why Tumors Become Drug-Resistant
New findings could lead to drugs that fight back when tumors don’t respond to treatment.
Monday, August 12, 2013
Reducing Caloric Intake Delays Nerve Cell Loss
Study points to role of protein in anti-aging benefits of calorie restriction.
Thursday, May 23, 2013
Study IDs Key Protein for Cell Death
Findings may offer a new way to kill cancer cells by forcing them into an alternative programmed-death pathway.
Tuesday, May 14, 2013
Device Finds Stray Cancer Cells in Patients’ Blood
A microfluidic device that captures circulating tumor cells could give doctors a noninvasive way to diagnose and track cancers.
Wednesday, April 10, 2013
Sorting out the Structure of a Parkinson’s Protein
Computer modeling may resolve conflicting results and offer hints for new drug-design strategies.
Tuesday, April 02, 2013
Scientific News
Non-Disease Proteins Kill Brain Cells
Scientists at the forefront of cutting-edge research into neurodegenerative diseases such as Alzheimer’s and Parkinson’s have shown that the mere presence of protein aggregates may be as important as their form and identity in inducing cell death in brain tissue.
Closing the Loop on an HIV Escape Mechanism
Research team finds that protein motions regulate virus infectivity.
New Class of RNA Tumor Suppressors Identified
Two short, “housekeeping” RNA molecules block cancer growth by binding to an important cancer-associated protein called KRAS. More than a quarter of all human cancers are missing these RNAs.
Gut Microbes Signal to the Brain When They're Full
Don't have room for dessert? The bacteria in your gut may be telling you something.
Turning up the Tap on Microbes Leads to Better Protein Patenting
Mining millions of proteins could become faster and easier with a new technique that may also transform the enzyme-catalyst industry, according to University of California, Davis, researchers.
Exploring the Causes of Cancer
Queen's research to understand the regulation of a cell surface protein involved in cancer.
Measuring microRNAs in Blood to Speed Cancer Detection
A simple, ultrasensitive microRNA sensor holds promise for the design of new diagnostic strategies and, potentially, for the prognosis and treatment of pancreatic and other cancers.
Novel Proteins Linked to Huntington's Disease
University of Florida Health researchers have made a new discovery about Huntington's disease, showing that the gene that causes the fatal disorder makes an unexpected "cocktail" of mutant proteins that accumulate in the brain.
Enzyme Critical to Maintaining Telomere Length Discovered
New method expected to speed understanding of short telomere diseases and cancer.
New Method Identifies Up to Twice as Many Proteins and Peptides
An international team of researchers developed a method that identifies up to twice as many proteins and peptides in mass spectrometry data than conventional approaches.
Scroll Up
Scroll Down
Skyscraper Banner

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
2,800+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,000+ scientific videos