PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Polymer gel, heal thyself: University of Pittsburgh engineering team proposes new composites that can regenerate when damaged

2013-11-26
(Press-News.org) Contact information: John Fedele
jfedele@pitt.edu
412-624-4148
University of Pittsburgh
Polymer gel, heal thyself: University of Pittsburgh engineering team proposes new composites that can regenerate when damaged

PITTSBURGH (November 25, 2013) … When a chair leg breaks or a cell phone shatters, either must be repaired or replaced. But what if these materials could be programmed to regenerate-themselves, replenishing the damaged or missing components, and thereby extend their lifetime and reduce the need for costly repairs?

That potential is now possible according to researchers at the University of Pittsburgh Swanson School of Engineering, who have developed computational models to design a new polymer gel that would enable complex materials to regenerate themselves. The article, "Harnessing Interfacially-Active Nanorods to Regenerate Severed Polymer Gels" (DOI: 10.1021/nl403855k), was published November 19 in the American Chemical Society journal Nano Letters.

Principal investigator is Anna C. Balazs, PhD, the Swanson School's Distinguished Robert v. d. Luft Professor of chemical and petroleum engineering, and co-authors are Xin Yong, PhD, postdoctoral associate, who is the article's lead author; Olga Kuksenok, PhD, research associate professor; and Krzysztof Matyjaszewski, PhD, J.C. Warner University Professor of Natural Sciences, department of chemistry at Carnegie Mellon University.

"This is one of the holy grails of materials science," noted Dr. Balazs. "While others have developed materials that can mend small defects, there is no published research regarding systems that can regenerate bulk sections of a severed material. This has a tremendous impact on sustainability because you could potentially extend the lifetime of a material by giving it the ability to regrow when damaged."

The research team was inspired by biological processes in species such as amphibians, which can regenerate severed limbs. This type of tissue regeneration is guided by three critical instruction sets – initiation, propagation, and termination – which Dr. Balazs describes as a "beautiful dynamic cascade" of biological events.

"When we looked at the biological processes behind tissue regeneration in amphibians, we considered how we would replicate that dynamic cascade within a synthetic material," Dr. Balazs said. "We needed to develop a system that first would sense the removal of material and initiate regrowth, then propagate that growth until the material reached the desired size and then, self-terminate the process."

"Our biggest challenge was to address the transport issue within a synthetic material," Dr. Balazs said. "Biological organisms have circulatory systems to achieve mass transport of materials like blood cells, nutrients and genetic material. Synthetic materials don't inherently possess such a system, so we needed something that acted like a sensor to initiate and control the process."

The team developed a hybrid material of nanorods embedded in a polymer gel, which is surrounded by a solution containing monomers and cross-linkers (molecules that link one polymer chain to another) in order to replicate the dynamic cascade. When part of the gel is severed, the nanorods near the cut act as sensors and migrate to the new interface. The functionalized chains or "skirts" on one end of these nanorods keeps them localized at the interface and the sites (or "initiators") along the rod's surface trigger a polymerization reaction with the monomer and cross-linkers in the outer solution. Drs. Yong and Kuksenok developed the computational models, and thereby established guidelines to control the process so that the new gel behaves and appears like the gel it replaced, and to terminate the reaction so that the material would not grow out of control.

Drs. Balazs, Kuksenok and Yong also credit Krzysztof Matyjaszewski, who contributed toward the understanding of the chemistry behind the polymerization process. "Our collaboration with Prof. Matyjaszewski was exceptionally valuable in allowing us to accurately account for all the complex chemical reactions involved in the regeneration processes" said Dr. Kuksenok.

"The most beautiful yet challenging part was designing the nanorods to serve multiple roles," Dr. Yong said. "In effect, they provide the perfect vehicle to trigger a synthetic dynamic cascade." The nanorods are approximately ten nanometers in thickness, about 10,000 times smaller than the diameter of a human hair.

In the future, the researchers plan to improve the process and strengthen the bonds between the old and newly formed gels, and for this they were inspired by another nature metaphor, the giant sequoia tree. "One sequoia tree will have a shallow root system, but when they grow in numbers, the root systems intertwine to provide support and contribute to their tremendous growth," Dr. Balazs explains. Similarly, the skirts on the nanorods can provide additional strength to the regenerated material.

The next generation of research would further optimize the process to grow multiple layers, creating more complex materials with multiple functions.



INFORMATION:



ELSE PRESS RELEASES FROM THIS DATE:

Large study shows pollution impact on coral reefs -- and offers solution

2013-11-26
Large study shows pollution impact on coral reefs -- and offers solution CORVALLIS, Ore. – One of the largest and longest experiments ever done to test the impact of nutrient loading on coral reefs today confirmed what scientists have long ...

ADHD linked to social and economic disadvantage

2013-11-26
ADHD linked to social and economic disadvantage Scientists have found evidence of a link between social and economic status and childhood attention deficit disorder in the UK Scientists have found evidence of a link between social and economic status and ...

Implantable slimming aid

2013-11-26
Implantable slimming aid Gene network regulates blood-fat levels Humankind has a weight problem – and not only in the industrialised nations, either: the growing prosperity in many Asian or Latin American countries goes hand in hand with a way of life that ...

Seahorse heads have a 'no wake zone' that's made for catching prey

2013-11-26
Seahorse heads have a 'no wake zone' that's made for catching prey

A gene mutation for excessive alcohol drinking found

2013-11-26
A gene mutation for excessive alcohol drinking found UK researchers have discovered a gene that regulates alcohol consumption and when faulty can cause excessive drinking. They have also identified the mechanism underlying this phenomenon. The study showed ...

Protective effects of dl-3n-butylphthalide against diffuse brain injury

2013-11-26
Protective effects of dl-3n-butylphthalide against diffuse brain injury Dl-3n-butylphthalide can effectively treat cerebral ischemia; however, the mechanisms underlying the effects of dl-3n-butylphthalide on microcirculation disorders following diffuse brain injury ...

Why do stroke patients show poor limb motor function recovery?

2013-11-26
Why do stroke patients show poor limb motor function recovery? Negative motor evoked potentials after cerebral infarction, indicative of poor recovery of limb motor function, tend to be accompanied by changes in fractional anisotropy values and the cerebral peduncle ...

An abnormal resting-state functional brain network indicates progression towards AD

2013-11-26
An abnormal resting-state functional brain network indicates progression towards AD Although we know that mild cognitive impairment is a transitional stage between normal aging and Alzheimer's disease, changes in brain networks during this transformation have ...

Flower power

2013-11-26
Flower power Researchers breed new varieties of chamomile Chamomile is a medicinal plant used mainly in the treatment of stomach and intestinal diseases, including the field of veterinary medicine. Agricultural scientist Bettina ...

Researchers have a nose for how probiotics could affect hay fever

2013-11-26
Researchers have a nose for how probiotics could affect hay fever A study has shown that a daily probiotic drink changed how cells lining the nasal passages of hay fever sufferers reacted to a single out-of-season challenge. However, it did not ...

LAST 30 PRESS RELEASES:

Revised diagnostic criteria for vascular cognitive impairment and dementia—The VasCog-2-WSO criteria

The ATREIDES program in search of lost exo-Neptunes

Ancient crop discovered in the Canary Islands thanks to archaeological DNA

Placental research may transform our understanding of autism and human brain evolution

Mapping the Universe, faster and with the same accuracy

Study isolates population aging as primary driver of musculoskeletal disorders

Designing a sulfur vacancy redox disruptor for photothermoelectric and cascade‑catalytic‑driven cuproptosis–ferroptosis–apoptosis therapy

Recent advances in dynamic biomacromolecular modifications and chemical interventions: Perspective from a Chinese chemical biology consortium

CRF and the Jon DeHaan Foundation to launch TCT AI Lab at TCT 2025

Canada’s fastest academic supercomputer is now online at SFU after $80m upgrades

Architecture’s past holds the key to sustainable future

Laser correction for short-sightedness is safe and effective for older teenagers

About one in five people taking Ozempic, Wegovy or Mounjaro say food tastes saltier or sweeter than before

Taking semaglutide turns down food noise, research suggests

Type 2 diabetes may double risk of sepsis, large community-based study suggests

New quantum sensors can withstand extreme pressure

Tirzepatide more cost-effective than semaglutide in patients with knee osteoarthritis and obesity

GLP-1 drugs shown cost-effective for knee osteoarthritis and obesity

Interactive apps, AI chatbots promote playfulness, reduce privacy concerns

How NIL boosts college football’s competitive balance

Moffitt researchers develop machine learning model to predict urgent care visits for lung cancer patients

Construction secrets of honeybees: Study reveals how bees build hives in tricky spots

Wheat disease losses total $2.9 billion across the United States and Canada between 2018 and 2021

New funding fuels development of first potentially regenerative treatment for multiple sclerosis

NJIT student–faculty team wins best presentation award for ant swarm simulation

Ants defend plants from herbivores but can hinder pollination

When the wireless data runs dry

Inquiry into the history of science shows an early “inherence” bias

Picky eaters endure: Ecologists use DNA to explore diet breadth of wild herbivores

Study suggests most Americans would be healthier without daylight saving time

[Press-News.org] Polymer gel, heal thyself: University of Pittsburgh engineering team proposes new composites that can regenerate when damaged