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 gelís 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 gelís 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 ó such as being pushed through an injection needle ó 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

Bioengineered nanoparticles show promise for fibrinogen manufacture, says Journal of Pharmaceutical Analysis study: Scientists engineer a nanoparticle polymer that can selectively bind to fibrinogen in human plasma, presenting a pathway for improved drug development January 14th, 2022

Photon recycling Ė The key to high-efficiency perovskite solar cells January 14th, 2022

NSF funds Rice effort to measure, preserve quantum entanglement: Physicist Guido Pagano wins CAREER Award to develop tools for quantum computing January 14th, 2022

Tuning the bonds of paired quantum particles to create dissipationless flow: A tunable platform made from atomically thin materials may help researchers figure out how to create a robust quantum condensate that can flow without losing energy January 14th, 2022

Govt.-Legislation/Regulation/Funding/Policy

Nanostructures get complex with electron equivalents: Nanoparticles of two different sizes break away from symmetrical designs January 14th, 2022

Physicists watch as ultracold atoms form a crystal of quantum tornadoes: The new observations record a key crossover from classical to quantum behavior January 7th, 2022

Nanotube fibers stand strong -- but for how long? Rice scientists calculate how carbon nanotubes and their fibers experience fatigue December 24th, 2021

Record-breaking hole mobility heralds a flexible future for electronics: Researchers from The University of Tsukuba grow a germanium thin film on a flexible polyimide substrate, resulting in a material with the highest hole mobility reported to date December 24th, 2021

Nanomedicine

Bioengineered nanoparticles show promise for fibrinogen manufacture, says Journal of Pharmaceutical Analysis study: Scientists engineer a nanoparticle polymer that can selectively bind to fibrinogen in human plasma, presenting a pathway for improved drug development January 14th, 2022

New photonic effect could speed drug development: Twisted semiconductor nanostructures convert red light into the twisted blue light in tiny volumes, which may help develop chiral drugs January 14th, 2022

UT Southwestern develops nanotherapeutic to ward off liver cancer January 14th, 2022

Preserving the goods: A new technique for isolating intact lysosomes from cell cultures: Scientists advance the study of fragile digestive organelles by developing strategy to rapidly extract them from cells using magnetic nanoparticles January 7th, 2022

Discoveries

Towards high-performance organic optoelectronics with better crystallinity at semiconductor interface: Organic molecular interfaces with minimized structural mismatch and spontaneous electron transfer could open doors to high-efficiency optoelectronics January 14th, 2022

Bioengineered nanoparticles show promise for fibrinogen manufacture, says Journal of Pharmaceutical Analysis study: Scientists engineer a nanoparticle polymer that can selectively bind to fibrinogen in human plasma, presenting a pathway for improved drug development January 14th, 2022

UT Southwestern develops nanotherapeutic to ward off liver cancer January 14th, 2022

The free-energy principle explains the brain January 14th, 2022

Materials/Metamaterials

Nanotube fibers stand strong -- but for how long? Rice scientists calculate how carbon nanotubes and their fibers experience fatigue December 24th, 2021

Nanodiamonds are key to efficient hydrogen purification: Nanodiamonds may be tiny, but they can help with one of the biggest problems facing humanity today: Climate change December 17th, 2021

Texas A&M chemist recognized for paving the way toward artificial intelligence and energy conversion December 10th, 2021

Researchers develop polyimide-mica nanocomposite film with high resistance to low earth orbit environments December 3rd, 2021

Announcements

Nanostructures get complex with electron equivalents: Nanoparticles of two different sizes break away from symmetrical designs January 14th, 2022

New photonic effect could speed drug development: Twisted semiconductor nanostructures convert red light into the twisted blue light in tiny volumes, which may help develop chiral drugs January 14th, 2022

UT Southwestern develops nanotherapeutic to ward off liver cancer January 14th, 2022

The free-energy principle explains the brain January 14th, 2022

Military

Nanostructures get complex with electron equivalents: Nanoparticles of two different sizes break away from symmetrical designs January 14th, 2022

Physicists watch as ultracold atoms form a crystal of quantum tornadoes: The new observations record a key crossover from classical to quantum behavior January 7th, 2022

Series of preclinical studies supports the Armyís pan-coronavirus vaccine development strategy December 17th, 2021

Light speed advances: UD Prof. Tingyi Gu receives DARPA Young Faculty Award December 3rd, 2021

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