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 2,600+ scientific posters on ePosters
  • More than 3,800+ 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

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
Viruses Join Fight Against Harmful Bacteria
Engineered viruses could combat human disease and improve food safety.
Friday, September 25, 2015
Targeting DNA
Protein-based sensor could detect viral infection or kill cancer cells.
Tuesday, September 22, 2015
A Metabolic Master Switch Underlying Human Obesity
Researchers find pathway that controls metabolism by prompting fat cells to store or burn fat.
Friday, August 21, 2015
Identifying a Key Growth Factor in Cell Proliferation
Researchers discover that aspartate is a limiter of cell proliferation.
Friday, July 31, 2015
Firms “Under-invest” in Long-Term Cancer Research
Tweaks to the R&D pipeline could create new drugs and greater social benefit.
Thursday, July 30, 2015
Nanoparticles Can Clean Up Environmental Pollutants
Researchers have found that nanomaterials and UV light can “trap” chemicals for easy removal from soil and water.
Thursday, July 23, 2015
Tough biogel structures produced by 3-D printing
Researchers have developed a new way of making tough — but soft and wet — bio-compatible materials, called “hydrogels,” into complex and intricately patterned shapes.
Wednesday, June 03, 2015
Diagnosing Cancer with Help from Bacteria
Engineered probiotics can detect tumors in the liver.
Friday, May 29, 2015
Master Gene Regulator Could Be New Target For Schizophrenia Treatment
Researchers at MIT’s Picower Institute for Learning and Memory have identified a master genetic regulator that could account for faulty brain functions that contribute to schizophrenia.
Wednesday, May 27, 2015
Designing Better Medical Implants
A team of MIT researchers have discovered a novel method for reducing the typical immune system rejection response when implanting biomedical devices into the body.
Wednesday, May 20, 2015
Brain Tumor Weakness Identified
Discovery could offer a new target for treatment of glioblastoma.
Thursday, April 09, 2015
New Nanodevice Defeats Drug Resistance
Tiny particles embedded in gel can turn off drug-resistance genes, then release cancer drugs.
Wednesday, March 04, 2015
New Nanodevice Defeats Drug Resistance
Tiny particles embedded in gel can turn off drug-resistance genes, then release cancer drugs.
Tuesday, March 03, 2015
Proteins Drive Cancer Cells To Change States
When RNA-binding proteins are turned on, cancer cells get locked in a proliferative state.
Monday, December 15, 2014
Scientific News
Tolerant Immune System Increases Cancer Risk
Researchers have found that individuals with high immunoCRIT ratios may have an increased risk of developing certain cancers.
Developing a Gel that Mimics Human Breast for Cancer Research
Scientists at the Universities of Manchester and Nottingham have been funded to develop a gel that will match many of the biological structures of human breast tissue, to advance cancer research and reduce animal testing.
New Gene Therapy for Vision Loss From a Mitochondrial Disease
NIH-funded study shows success in targeting mitochondrial DNA in mice.
Predictive Model for Breast Cancer Progression
Biomedical engineers have demonstrated a proof-of-principle technique that could give women and their oncologists more personalized information to help them choose options for treating breast cancer.
Specific Variations in RNA Splicing Linked to Breast Cancer
Researchers have identified cellular changes that may play a role in converting normal breast cells into tumors. Targeting these changes could potentially lead to therapies for some forms of breast cancer.
Gene Expression: A Snapshot of Stem Cell Development
New genes found that regulate development of stem cells.
Assessing Cancer Patient Survival and Drug Sensitivity
RNA editing events another way to investigate biomarkers and therapy targets.
Editing Genes to Create HIV Killers
Seattle scientists have managed to genetically transform human cells in the lab from HIV targets to HIV killers, and the technique could have implications for cancer and other diseases.
Researchers Disguise Drugs As Platelets to Target Cancer
Researchers have for the first time developed a technique that coats anticancer drugs in membranes made from a patient’s own platelets.
A New Single-Molecule Tool to Observe Enzymes at Work
A team of scientists at the University of Washington and the biotechnology company Illumina have created an innovative tool to directly detect the delicate, single-molecule interactions between DNA and enzymatic proteins.

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
2,600+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,800+ scientific videos