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

Carnegie Mellon chemists create nanofibers using unprecedented new method

Carnegie Mellon chemists create nanofibers using unprecedented new method
2014-07-31
(Press-News.org) PITTSBURGH—Researchers from Carnegie Mellon University have developed a novel method for creating self-assembled protein/polymer nanostructures that are reminiscent of fibers found in living cells. The work offers a promising new way to fabricate materials for drug delivery and tissue engineering applications. The findings were published in the July 28 issue of Angewandte Chemie International Edition.

"We have demonstrated that, by adding flexible linkers to protein molecules, we can form completely new types of aggregates. These aggregates can act as a structural material to which you can attach different payloads, such as drugs. In nature, this protein isn't close to being a structural material," said Tomasz Kowalewski, professor of chemistry in Carnegie Mellon's Mellon College of Science.

The building blocks of the fibers are a few modified green fluorescent protein (GFP) molecules linked together using a process called click chemistry. An ordinary GFP molecule does not normally bind with other GFP molecules to form fibers. But when Carnegie Mellon graduate student Saadyah Averick, working under the guidance of Krzysztof Matyjaszewski, the J.C. Warner Professor of Natural Sciences and University Professor of Chemistry in CMU's Mellon College of Science, modified the GFP molecules and attached PEO-dialkyne linkers to them, they noticed something strange — the GFP molecules appeared to self-assemble into long fibers. Importantly, the fibers disassembled after being exposed to sound waves, and then reassembled within a few days. Systems that exhibit this type of reversible fibrous self-assembly have been long sought by scientists for use in applications such as tissue engineering, drug delivery, nanoreactors and imaging.

"This was purely curiosity-driven and serendipity-driven work," Kowalewski said. "But where controlled polymerization and organic chemistry meet biology, interesting things can happen."

The research team observed the fibers using confocal light microscopy, confirmed their assembly using dynamic light scattering and studied their morphology using atomic force microscopy (AFM). They also observed that the fibers were fluorescent, indicating that the GFP molecules retained their 3-D structure while linked together.

To determine what processes were driving the self-assembly, Matyjaszewski and Kowalewski turned to Anna Balazs, Distinguished Professor of Chemical Engineering and the Robert v. d. Luft Professor at the University of Pittsburgh. A leading expert in modeling the dynamics and mechanical properties of mesoscale systems, Balazs ran a computer simulation of the GFP molecules' self-assembly process using a technique called dissipative particle dynamics, a type of coarse-grained molecular dynamics method. The simulation confirmed the modified GFP's tendency to form fibers and revealed that the self-assembly process was driven by the interaction of hydrophobic patches on the surfaces of individual GFP molecules. In addition, Balazs's simulated fibers closely corresponded with what Kowalewski observed using AFM imaging.

"Our protein-polymer system gives us an atomically precise, very well-defined nanoscale building object onto which we can attach different handles in very precisely defined positions. It can be used in a way that wasn't ever intended by biology," Kowalewski said.

INFORMATION: In addition to Averick, Balazs, Kowalewski and Matyjaszewski, co-authors of the study include Carnegie Mellon's Orsolya Karacsony and Jacob Mohin, University of Pittsburgh's Xin Yong and Nicholas M. Moellers, Oregon State University's Bradley F. Woodman and Ryan A. Mehl, and Zhejiang University's Weipu Zhu. The research was supported by the U.S. Department of Energy, National Science Foundation, Carnegie Mellon's CRP Consortium and Oregon State University.

About Carnegie Mellon University: Carnegie Mellon is a private, internationally ranked research university with programs in areas ranging from science, technology and business, to public policy, the humanities and the arts. More than 12,000 students in the university's seven schools and colleges benefit from a small student-to-faculty ratio and an education characterized by its focus on creating and implementing solutions for real problems, interdisciplinary collaboration and innovation. A global university, Carnegie Mellon has campuses in Pittsburgh, Pa., California's Silicon Valley and Qatar, and programs in Africa, Asia, Australia, Europe and Mexico.

[Attachments] See images for this press release:
Carnegie Mellon chemists create nanofibers using unprecedented new method

ELSE PRESS RELEASES FROM THIS DATE:

Groundbreaking research maps cultural history

Groundbreaking research maps cultural history
2014-07-31
New research from Northeastern University has mapped the intellectual migration network in North America and Europe over a 2,000-year span. The team of network scientists used the birth and death locations of more than 150,000 intellectuals to map their mobility patterns in order to identify the major cultural centers on the two continents over two millennia. In the new paper, to be published Friday in the journal Science, the researchers found how locations such as Rome, London, and Paris have emerged as cultural hubs as more intellectuals died in these cities than ...

NIST corrosion lab tests suggest need for underground gas tank retrofits

NIST corrosion lab tests suggest need for underground gas tank retrofits
2014-07-31
A hidden hazard lurks beneath many of the roughly 156,000 gas stations across the United States. The hazard is corrosion in parts of underground gas storage tanks—corrosion that could result in failures, leaks and contamination of groundwater, a source of drinking water. In recent years, field inspectors in nine states have reported many rapidly corroding gas storage tank components such as sump pumps. These incidents are generally associated with use of gasoline-ethanol blends and the presence of bacteria, Acetobacter aceti, which convert ethanol to acetic acid, a component ...

New bipartisan House bill draws on U-M health research

2014-07-31
ANN ARBOR—A new bill introduced in Congress with bipartisan support would allow Medicare to test a concept born from University of Michigan research, which could improve the health of patients with chronic illness while reducing what they spend on the medicines and tests they need most. The bill, introduced last week by U.S. Reps. Diane Black and Earl Blumenauer, grew out of a decade of work by health policy researchers affiliated with the U-M's Institute for Healthcare Policy and Innovation. It would allow Medicare Advantage plans to use innovative "value-based" insurance ...

Parenting skills improve in ADHD parents with medication

2014-07-31
Parenting skills of adults with ADHD improve when their ADHD is treated with medication, according to Penn State College of Medicine researchers. At least 25 percent of clinic-referred children with attention deficit/hyperactivity disorder have a parent with ADHD. "Parents with ADHD are at increased risk to engage in problematic parenting techniques, including inconsistent disciplinary practices, making ineffectual commands and diminished use of praise," said James Waxmonsky, associate professor of psychiatry. "Having a parent with ADHD also decreases the chances that ...

The 'memory' of starvation is in your genes

2014-07-31
During the winter of 1944, the Nazis blocked food supplies to the western Netherlands, creating a period of widespread famine and devastation. The impact of starvation on expectant mothers produced one of the first known epigenetic "experiments" — changes resulting from external rather than genetic influences — which suggested that the body's physiological responses to hardship could be inherited. The underlying mechanism, however, remained a mystery. In a paper published recently in the journal Cell, Dr. Oded Rechavi, Dr. Leah Houri-Ze'ev and Dr. Sarit Anava of Tel ...

NASA sees Tropical Storm Halong move northwest of Guam

NASA sees Tropical Storm Halong move northwest of Guam
2014-07-31
NASA's Tropical Rainfall Measuring Mission or TRMM Satellite passed over Guam as heavy rain fell over the island while Tropical Storm Halong's center passed just to the north of the island. The TRMM satellite flew above tropical storm Halong on July 31, 2014 at 0904 UTC (August 1, 2014 at 7:04 p.m. local time, Guam). At NASA's Goddard Space Flight Center in Greenbelt, Maryland TRMM data was used to create a rainfall analysis. The analysis derived TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) data was overlaid on a visible/infrared image from Japan's MTSAT-2 ...

Asteroid attacks significantly altered ancient Earth

Asteroid attacks significantly altered ancient Earth
2014-07-31
TEMPE, Ariz. – New research shows that more than four billion years ago, the surface of Earth was heavily reprocessed – or mixed, buried and melted – as a result of giant asteroid impacts. A new terrestrial bombardment model based on existing lunar and terrestrial data sheds light on the role asteroid bombardments played in the geological evolution of the uppermost layers of the Hadean Earth (approximately 4 to 4.5 billion years ago). An international team of researchers published their findings in the July 31, 2014 issue of Nature. "When we look at the present day, ...

Mosaicism: Study clarifies parents as source of new disease mutations

2014-07-31
HOUSTON – (July 31, 2014) – Scientists have long speculated that mosaicism – a biological phenomenon, in which cells within the same person have a different genetic makeup – plays a bigger role in the transmission of rare disease mutations than is currently known. A study conducted by an international team of scientists led by Baylor College of Medicine sheds new light on the frequency of mosaicism in genomic disorders and its influence on recurrence risk. The study, which was published today in the American Journal of Human Genetics, also included scientists from the ...

In high-stakes soccer, goalkeepers exhibit 'gambler's fallacy'

2014-07-31
When goalkeepers are pitted against multiple kickers in tense penalty shootouts, their attempts to dive for the ball show a predictable pattern that kickers would do well to exploit. After kickers repeatedly kick in one direction, goalkeepers become increasingly likely to dive in the opposite direction, according to an analysis of all 361 kicks from the 37 penalty shootouts that occurred in World Cup and UEFA Euro Cup matches over a 36-year period. The findings reported in the Cell Press journal Current Biology on July 31 highlight the importance of monitoring and predicting ...

Selective logging takes its toll on mammals, amphibians

Selective logging takes its toll on mammals, amphibians
2014-07-31
The selective logging of trees in otherwise intact tropical forests can take a serious toll on the number of animal species living there. Mammals and amphibians are particularly sensitive to the effects of high-intensity logging, according to researchers in the Cell Press journal Current Biology on July 31 who conducted a meta-analysis of almost 50 previously published studies from around the world. "Selective logging in the tropics is not a new phenomenon, and it will continue to be a common use of the forest," says Zuzana Burivalova of ETH Zurich, Switzerland. "We hope ...

LAST 30 PRESS RELEASES:

Scientists model 'true prevalence' of COVID-19 throughout pandemic

New breakthrough to help immune systems in the fight against cancer

Through the thin-film glass, researchers spot a new liquid phase

Administering opioids to pregnant mice alters behavior and gene expression in offspring

Brain's 'memory center' needed to recognize image sequences but not single sights

Safety of second dose of mRNA COVID-19 vaccines after first-dose allergic reactions

Changes in disparities in access to care, health after Medicare eligibility

Use of high-risk medications among lonely older adults

65+ and lonely? Don't talk to your doctor about another prescription

Exosome formulation developed to deliver antibodies for choroidal neovascularization therapy

Second COVID-19 mRNA vaccine dose found safe following allergic reactions to first dose

Plant root-associated bacteria preferentially colonize their native host-plant roots

Rare inherited variants in previously unsuspected genes may confer significant risk for autism

International experts call for a unified public health response to NAFLD and NASH epidemic

International collaboration of scientists rewrite the rulebook of flowering plant genetics

Improving air quality reduces dementia risk, multiple studies suggest

Misplaced trust: When trust in science fosters pseudoscience

Two types of blood pressure meds prevent heart events equally, but side effects differ

New statement provides path to include ethnicity, ancestry, race in genomic research

Among effective antihypertensive drugs, less popular choice is slightly safer

Juicy past of favorite Okinawan fruit revealed

Anticipate a resurgence of respiratory viruses in young children

Anxiety, depression, burnout rising as college students prepare to return to campus

Goal-setting and positive parent-child relationships reduce risk of youth vaping

New research identifies cancer types with little survival improvements in adolescents and young adul

Oncotarget: Replication-stress sensitivity in breast cancer cells

Oncotarget: TERT and its binding protein: overexpression of GABPA/B in gliomas

Development of a novel technology to check body temperature with smartphone camera

The mechanics of puncture finally explained

Extreme heat, dry summers main cause of tree death in Colorado's subalpine forests

[Press-News.org] Carnegie Mellon chemists create nanofibers using unprecedented new method