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June 2013
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September 2013

Insect-inspired super rubber moves toward practical uses in medicine

The remarkable, rubber-like protein that enables dragonflies, grasshoppers and other insects to flap their wings, jump and chirp has major potential uses in medicine, scientists conclude in an article in the journal ACS Macro Letters. It evaluates the latest advances toward using a protein called resilin in nanosprings, biorubbers, biosensors and other applications.

Kristi Kiick and colleagues explain that scientists discovered resilin a half-century ago in the wing hinges of locusts and elastic tendons of dragonflies. The extraordinary natural protein tops the best synthetic rubbers. Resilin can stretch to three times its original length, for instance, and then spring back to its initial shape without losing its elasticity, despite repeated stretching and relaxing cycles. That’s a crucial trait for insects that must flap or jump millions of times over their lifetimes. Scientists first synthesized resilin in 2005 and have been striving to harness its properties in medicine.

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Steering stem cells with magnets

Quinn Eastman

July 16, 2013

Magnets could be a tool for directing stem cells’ healing powers to treat conditions such as heart disease or vascular disease.

By feeding stem cells tiny particles made of magnetized iron oxide, scientists at Emory and Georgia Tech can then use magnets to attract the cells to a particular location in a mouse's body after intravenous injection.

[...]

The type of cells used in the study, mesenchymal stem cells, are not embryonic stem cells. Mesenchymal stem cells can be readily obtained from adult tissues such as bone marrow or fat. They are capable of becoming bone, fat and cartilage cells, but not other types of cell such as muscle or brain. They secrete a variety of nourishing and anti-inflammatory factors, which could make them valuable tools for treating conditions such as cardiovascular disease or autoimmune disorders.

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Researchers create the inner ear from stem cells, opening potential for new treatments

July 10, 2013

Indiana University scientists have transformed mouse embryonic stem cells into key structures of the inner ear. The discovery provides new insights into the sensory organ's developmental process and sets the stage for laboratory models of disease, drug discovery and potential treatments for hearing loss and balance disorders.

A research team led by Eri Hashino, Ph.D., Ruth C. Holton Professor of Otolaryngology at Indiana University School of Medicine, reported that by using a three-dimensional cell culture method, they were able to coax stem cells to develop into inner-ear sensory epithelia—containing hair cells, supporting cells and neurons—that detect sound, head movements and gravity. The research was reportedly online Wednesday in the journal Nature.

Previous attempts to "grow" inner-ear hair cells in standard cell culture systems have worked poorly in part because necessary cues to develop hair bundles—a hallmark of sensory hair cells and a structure critically important for detecting auditory or vestibular signals—are lacking in the flat cell-culture dish. But, Dr. Hashino said, the team determined that the cells needed to be suspended as aggregates in a specialized culture medium, which provided an environment more like that found in the body during early development.

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Nanoparticles could power 'electronic skin' in the future

By Devin Coldewey

July 10, 2013

A new development in nanotechnology may enable "electronic skin" for robots and prosthetic limbs, offering sensitivity not just to pressure, but to humidity and temperature — and it's even flexible.

The new material is developed by chemical engineers at the Israel Institute of Technology, who found that a certain type of gold nanoparticle changed how it conducted electricity based on pressure.

These nanoparticles are only 5-8 nanometers in diameter, comprising a gold core and a spiky, protective outer layer. When sandwiched into a special film, the way that film is bent or pressed may cause the nanoparticles to spread out or bunch together, changing how well electricity passes between them.

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Study Challenges Long-held Assumption of Gene Expression in Embryonic Stem Cells

July 3, 2013

CAMBRIDGE, Mass. – Whitehead Institute researchers have determined that the transcription factor Nanog, which plays a critical role in the self-renewal of embryonic stem cells, is expressed in a manner similar to other pluripotency markers. This finding contradicts the field’s presumptions about this important gene and its role in the differentiation of embryonic stem cells.

A large body of research has reported that Nanog is allelically regulated—that is, only one copy of the gene is expressed at any given time—and fluctuations in its expression are responsible for the differences seen in individual embryonic stem (ES) cells’ predilection to differentiate into more specialized cells. These studies relied on cells that had a genetic marker or reporter inserted in the DNA upstream of the Nanog gene. This latest research, published in this week’s edition of the journal Cell Stem Cell, suggests that results from studies based on this approach could be called into question.

To quantify the variations in Nanog expression, Dina Faddah, a graduate student in the lab of Whitehead Institute Founding Member Rudolf Jaenisch, looked at hundreds of individual mouse ES cells with reporters inserted immediately downstream of the Nanog gene. One Nanog allele had a green reporter, while the other had a red reporter, allowing Faddah to determine which of the two alleles was being expressed.

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Groups attack Wisconsin Alumni Foundation's embryonic stem cell patent

By Kathleen Gallagher of the Journal Sentinel

Two nonprofit groups are continuing their challenge to one of the Wisconsin Alumni Foundation's key embryonic stem cell patents by asking a federal appeals court to invalidate it.

The Public Patent Foundation, based in New York, and Consumer Watchdog, Santa Monica, Calif., filed a brief Tuesday with the U.S. Court of Appeals for the Federal Circuit. The Public Patent Foundation was one of the successful challengers in the recently decided case in which the Supreme Court ruled that genes cannot be patented.

"WARF's broad patent on all human embryonic stem cells is invalid for a number of reasons and we are confident the Court of Appeals will agree," said Dan Ravicher, the foundation's executive director. The groups believe that all researchers should have unfettered access to embryonic stem cells, which scientists believe could help treat many diseases.

A WARF spokeswoman declined to comment, saying the foundation needed to review the filing with its attorneys.

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Waisman scientists model human disease in stem cells

by David Tenenbaum

 

Many scientists use animals to model human diseases. Mice can be obese or display symptoms of Parkinson's disease. Rats get Alzheimer's and diabetes.

But animal models are seldom perfect, and so scientists are looking at a relatively new type of stem cell, called the induced pluripotent stem cell (iPS cell), that can be grown into specialized cells that become useful models for human disease.

IPS cells are usually produced by reprogramming a skin sample into a primitive form that is able to develop into all of the specialized cells in the body. In the laboratories at the Waisman Center at UW-Madison, scientists are growing iPS cells into models of disorders caused by defective nerve cells. The technology depends on work pioneered over the past decade or so by Su-Chun Zhang, a neuroscientist who leads the iPS Core at Waisman, which also produces cells for other investigators on campus.

The multidisciplinary Waisman Center, now in its 40th year, combines treatment with clinical and basic research to address many of the most complex and disabling disorders of development.

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