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

Penn molecular scientists develop color-changing stress sensor

Penn molecular scientists develop color-changing stress sensor
2011-08-19
(Press-News.org) PHILADELPHIA — It is helpful — even life-saving — to have a warning sign before a structural system fails, but, when the system is only a few nanometers in size, having a sign that's easy to read is a challenge. Now, thanks to a clever bit of molecular design by University of Pennsylvania and Duke University bioengineers and chemists, such warning can come in the form of a simple color change.

The study was conducted by professor Daniel Hammer and graduate students Neha Kamat and Laurel Moses of the Department of Bioengineering in Penn's School of Engineering and Applied Science. They collaborated with associate professor Ivan Dmochowski and graduate student Zhengzheng Liao of the Department of Chemistry in Penn's School of Arts and Sciences, as well as professor Michael Therien and graduate student Jeff Rawson of Duke.

Their work was published in the journal Proceedings of the National Academy of Sciences.

The researchers' work involves two molecules: porphyrins, a class of naturally occurring pigments, and polymersomes, artificially engineered capsules that can carry a molecular payload in their hollow interiors. In this case, Kamat and Liao hypothesized that polymersomes could be used as stress sensors if their membranes were embedded with a certain type of light-emitting porphyrins.

The Penn researchers collaborated with the Therien lab, where the porphyrins were originally developed, to design polymersomes that were studded with the light-emitting molecules. When light is shined on these labeled polymersomes, the porphyrins absorb the light and then release it at a specific wavelength, or color. The Therien lab's porphyrins play a critical role in using the polymersomes as stress sensors, because their configuration and concentration controls the release of light.

"When you package these porphyrins in a confined environment, such as a polymersome membrane, you can modulate the light emission from the molecules," Hammer said. "If you put a stress on the confined environment, you change the porphyrin's configuration, and, because their optical release is tied to their configuration, you can use the optical release as a direct measure of the stress in the environment."

For example, the labeled polymersomes could be injected into the blood stream and serve as a proxy for neighboring red blood cells. As both the cells and polymersomes travel through an arterial blockage, for example, scientists would be able to better understand what happens to the blood cell membranes by making inferences from the stress label measurements.

The researchers calibrated the polymersomes by subjecting them to several kinds of controlled stresses — tension and heat, among others — and measuring their color changes. The changes are gradations of the near infrared spectrum, so measurements must be made by computers, rather than the naked eye. Rapidly advancing body-scanning technology, which uses light rather than magnetism or radiation, is well suited to this approach.

Other advances in medicine could benefit, as well. As cutting-edge pharmaceutical approaches already use similar molecular technology, the researchers' porphyrin labeling system could be integrated into medicine-carrying polymersomes.

"These kinds of tools could be used to monitor drug delivery, for example," Kamat said. "If we have a way to see how stressed the container is over time, we know how much of the drug has come out."

And, though the researchers chose the engineered polymersomes due to the wide range of stress they can endure, the same stress-labeling technique could soon be applied directly to naturally occurring tissues.

"One future application for this is to use dyes like these porphyrins but include them directly in a cellular membranes," Kamat said. "No one has taken a look at the intrinsic stress inside a membrane so these molecules would be perfect for the job."



INFORMATION:



The work was supported by the National Institutes of Health, the National Science Foundation and its Materials Research Science and Engineering Center program and the National Center for Research Resources.

Kamat is an NSF Graduate Fellow.


[Attachments] See images for this press release:
Penn molecular scientists develop color-changing stress sensor

ELSE PRESS RELEASES FROM THIS DATE:

Online Parcel Delivery Firm Says Small Businesses Must Capitalise on Mobile Sales Boom

2011-08-19
Britain's leading online parcel delivery specialist has called on small businesses to take advantage of the boom in sales through smartphones. Recent research has shown that more and more consumers are prepared to buy products through their mobile phones and are enjoying the freedom that mobile shopping offers. Bolton-based Parcel2Go helps businesses of all sizes organise shipping to countries across the world and suggests that small firms should take a proactive approach when it comes to building an online presence. People are now using their mobile phones to do ...

Emergency workers will respond

Emergency workers will respond
2011-08-19
Headlines screamed in the days following Hurricane Katrina: Police Quitting, Overwhelmed by Chaos. Pundits squawked about the flight of the "notoriously corrupt" New Orleans police force. City and emergency planners outside the devastated areas envisioned disasters happening in their own cities and widespread desertion by their first responders. But that's not a very realistic fear, according to UD's Joe Trainor, who recently conducted research on the subject. "Fire companies and police stations and hospitals should stop being concerned about whether individuals will ...

English language ads better reach Latino audience

2011-08-19
English language ads have a greater impact in mobilizing Latino voters than Spanish language ads, according to a study recently published in American Political Research, a SAGE journal. This study examined the effects of direct mail pieces on Latino voters. The direct mail piece, which was written in either English or Spanish, was sent to two separate groups while a third who received no mailing was used as a control group. The experiment was conducted in New York City Council District 21 prior to the February 2009 special election to fill a vacancy on the New York ...

Metabolic syndrome may cause kidney disease

2011-08-19
Metabolic syndrome comprises a group of medical disorders that increase people's risk of diabetes, heart disease, stroke, and premature death when they occur together. A patient is diagnosed with the syndrome when he or she exhibits three or more of the following characteristics: high blood pressure, high blood sugar, excess body fat in the waist/abdomen, low good cholesterol, and higher levels of fatty acids (the building blocks of fat). People with metabolic abnormalities are at increased risk of developing kidney disease, according to a study appearing in an upcoming ...

K.B. Makes a Splash by Winning EUR60,868.36 on Golden Riviera Casino

2011-08-19
Another Golden Riviera Online Casino patron has hit the Jackpot and is smiling all the way to the bank. K.B. won a whopping EUR60,868.36 on the ever-popular Progressive Video Slot, Cash Splash. Cash Splash Progressive Video Slot is the sequel to the much-loved Reel Slot of the same name, but now both versions are linked to the same Progressive giving players more chances to hit it big - just as K.B did! Casino Manager at Golden Riviera Casino released this statement: "All of us at Golden Riviera Casino wish to congratulate K.B. on an outstanding sweep! We love seeing ...

Acne-treating antibiotic cuts catheter infections in dialysis patients

2011-08-19
Washington, DC (August 19, 2011) — Antibiotics can help ward off serious bacterial infections in kidney disease patients who use tubes called catheters for their dialysis treatments. But if antibiotics are used too often, "super bugs" may crop up that are resistant to the drugs. A new randomized controlled clinical trial has shown that using an antibiotic that is not usually used to treat other serious infections may be a safe way to prevent bacterial infections in dialysis patients. The study, which included approximately 200 dialysis patients,was conducted by Rodrigo ...

Choosing a Trusted Lawyer to Pursue Compensation For You After an Injury

2011-08-19
Fairness, integrity and trust should be the foundation of all client-lawyer relationships. When you turn to an attorney to represent you in a sensitive matter, it's important to know that your interests will be protected by a person of integrity whom you trust to treat you fairly. This is particularly true in personal injury cases, such as car accidents. If you've been injured, getting your life back on track depends to a great degree on the success your attorney has on your behalf. An attorney who empathizes with your injuries and pursues compensation for you with passion ...

South Carolina Supreme Court Upholds Tiered Cap on Damages

2011-08-19
The Supreme Court of South Carolina recently upheld a state law that sets a two-tiered cap on damages in personal injury lawsuits against state entities. The scheme permits lawsuits of up to $1.2 million against state-employed physicians, surgeons and dentists, while capping lawsuits against all other state entities at $300,000 per person and $600,000 per occurrence. Larry and Jeannie Boiter challenged the validity of the law under the South Carolina state constitution after they were seriously injured in a motorcycle accident that occurred because of a burned-out traffic ...

The Two Faces of Enforcing New York's Marijuana Laws

2011-08-19
Although the New York legislature decriminalized possession of small amounts of marijuana in 1977, marijuana possession is still the top reason for arrests in New York City and one of the foremost reasons for arrest statewide. According to statistics released by the New York Division of Criminal Justice Services, New York City police officers have arrested 20 percent more people in the first quarter of 2011 than the same period in 2010 for marijuana possession. Across the state, police made 14,000 arrests for possession of marijuana, 13,000 of which were in New York ...

New Proposals to Protect Bicyclists in Boulder

2011-08-19
As the University of Colorado prepares for another academic year, Boulder transportation officials are considering several changes to protect pedestrians and bicyclists. Specifically, three proposals that build upon existing laws are under review. Officials first proposed a speed limit for bicyclists entering a crosswalk. Bicyclists would be required to slow down as they approach and travel through an intersection. Testing groups found that speeds of 8 miles per hour would give drivers a chance to see bicyclists and yield in a safe manner. Currently, the city code requires ...

LAST 30 PRESS RELEASES:

Exercise as an anti-ageing intervention to avoid detrimental impact of mental fatigue

UMass Amherst Nursing Professor Emerita honored as ‘Living Legend’

New guidelines aim to improve cystic fibrosis screening

Picky eaters by day, buffet by night: Butterfly, moth diets sync to plant aromas

Pennington Biomedical’s Dr. Leanne Redman honored with the E. V. McCollum Award from the American Society for Nutrition

CCNY physicists uncover electronic interactions mediated via spin waves

Researchers’ 3D-printing formula may transform future of foam

Nurture more important than nature for robotic hand

Drug-delivering aptamers target leukemia stem cells for one-two knockout punch

New study finds that over 95% of sponsored influencer posts on Twitter were not disclosed

New sea grant report helps great lakes fish farmers navigate aquaculture regulations

Strain “trick” improves perovskite solar cells’ efficiency

How GPS helps older drivers stay on the roads

Estrogen and progesterone stimulate the body to make opioids

Dancing with the cells – how acoustically levitating a diamond led to a breakthrough in biotech automation

Machine learning helps construct an evolutionary timeline of bacteria

Cellular regulator of mRNA vaccine revealed... offering new therapeutic options

Animal behavioral diversity at risk in the face of declining biodiversity

Finding their way: GPS ignites independence in older adult drivers

Antibiotic resistance among key bacterial species plateaus over time

‘Some insects are declining but what’s happening to the other 99%?’

Powerful new software platform could reshape biomedical research by making data analysis more accessible

Revealing capillaries and cells in living organs with ultrasound

American College of Physicians awards $260,000 in grants to address equity challenges in obesity care

Researchers from MARE ULisboa discover that the European catfish, an invasive species in Portugal, has a prolonged breeding season, enhancing its invasive potential

Rakesh K. Jain, PhD, FAACR, honored with the 2025 AACR Award for Lifetime Achievement in Cancer Research

Solar cells made of moon dust could power future space exploration

Deporting immigrants may further shrink the health care workforce

Border region emergency medical services in migrant emergency care

Resident physician intentions regarding unionization

[Press-News.org] Penn molecular scientists develop color-changing stress sensor