Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > New injectable gels toughen up after entering the body: These more durable gels could find applications in drug delivery and tissue engineering

When the new shear thinning hydrogel (top) is heated to body temperature, polymer chains join together to form a reinforcing network that improves the gel’s stability (bottom).
Image: Matt Glassman
When the new shear thinning hydrogel (top) is heated to body temperature, polymer chains join together to form a reinforcing network that improves the gel’s stability (bottom). Image: Matt Glassman

Abstract:
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.

New injectable gels toughen up after entering the body: These more durable gels could find applications in drug delivery and tissue engineering

Cambridge, MA | Posted on November 19th, 2012

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.

####

For more information, please click here

Contacts:
Caroline McCall
MIT News Office
E:
T: 617-253-1682

Copyright © MIT

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Drawing data in nanometer scale September 30th, 2022

Researchers unveil mystery inside Li- o2 batteries September 30th, 2022

Synthesis of air-stable room-temperature van der Waals magnetic thin flakes September 30th, 2022

ACM Research Launches New Furnace Tool for Thermal Atomic Layer Deposition to Support Advanced Semiconductor Manufacturing Requirements: Ultra Fn A Furnace Tool Shipped to China-Based Foundry Customer September 30th, 2022

Govt.-Legislation/Regulation/Funding/Policy

Drawing data in nanometer scale September 30th, 2022

New technique allows researchers to scrape beyond the surface of nanomaterials: Using a new secondary-ion mass spectrometry technique, research are getting a fresh look at MXenes and MAX phases September 23rd, 2022

Solvent study solves solar cell durability puzzle: Rice-led project could make perovskite cells ready for prime time September 23rd, 2022

Heat-resistant nanophotonic material could help turn heat into electricity: The key to beating the heat is degrading the materials in advance September 23rd, 2022

Nanomedicine

Cleveland researchers reveal new strategy to prevent blood clots without increasing the risk of bleeding: University Hospitals and Case Western Reserve University findings may be especially impactful for cancer patients who experience blood clot complications September 30th, 2022

Georgia State researchers discover novel way to treat IBD with lipid nanoparticles August 26th, 2022

Engineers fabricate a chip-free, wireless electronic “skin”: The device senses and wirelessly transmits signals related to pulse, sweat, and ultraviolet exposure, without bulky chips or batteries August 19th, 2022

Immune system: First image of antigen-bound T-cell receptor at atomic resolution: Antigen binding does not trigger any structural changes in T-cell receptors – Signal transduction probably occurs after receptor enrichment August 19th, 2022

Discoveries

Surface microstructures of lunar soil returned by Chang’e-5 mission reveal an intermediate stage in space weathering process September 30th, 2022

Researchers unveil mystery inside Li- o2 batteries September 30th, 2022

Synthesis of air-stable room-temperature van der Waals magnetic thin flakes September 30th, 2022

Layer Hall effect and hidden Berry curvature in antiferromagnetic insulators September 30th, 2022

Materials/Metamaterials

New technique allows researchers to scrape beyond the surface of nanomaterials: Using a new secondary-ion mass spectrometry technique, research are getting a fresh look at MXenes and MAX phases September 23rd, 2022

Wrapping of nanosize copper cubes can help convert carbon dioxide into other chemicals September 23rd, 2022

Upgrading your computer to quantum September 23rd, 2022

Digging a little deeper: New Earth Science Frontiers study explores the nanoscale properties of the Gulong shale oil reservoir: A new study elucidates the role of nanoscopic spaces in the in situ accumulation of shale oil in the Gulong-Qingshankou reservoir in China September 9th, 2022

Announcements

Researchers unveil mystery inside Li- o2 batteries September 30th, 2022

Synthesis of air-stable room-temperature van der Waals magnetic thin flakes September 30th, 2022

Layer Hall effect and hidden Berry curvature in antiferromagnetic insulators September 30th, 2022

ACM Research Launches New Furnace Tool for Thermal Atomic Layer Deposition to Support Advanced Semiconductor Manufacturing Requirements: Ultra Fn A Furnace Tool Shipped to China-Based Foundry Customer September 30th, 2022

Military

Solvent study solves solar cell durability puzzle: Rice-led project could make perovskite cells ready for prime time September 23rd, 2022

Heat-resistant nanophotonic material could help turn heat into electricity: The key to beating the heat is degrading the materials in advance September 23rd, 2022

Understanding outsize role of nanopores: New research reveals differences in pH, and more, about these previously mysterious environments August 26th, 2022

New chip ramps up AI computing efficiency August 19th, 2022

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project