Spotlight

Nanopores underlie our ability to tune in to a single voice

David L. Chandler, MIT News Office

Even in a crowded room full of background noise, the human ear is remarkably adept at tuning in to a single voice — a feat that has proved remarkably difficult for computers to match. A new analysis of the underlying mechanisms, conducted by researchers at MIT, has provided insights that could ultimately lead to better machine hearing, and perhaps to better hearing aids as well.

Our ears’ selectivity, it turns out, arises from evolution’s precise tuning of a tiny membrane, inside the inner ear, called the tectorial membrane. The viscosity of this membrane — its firmness, or lack thereof — depends on the size and distribution of tiny pores, just a few tens of nanometers wide. This, in turn, provides mechanical filtering that helps to sort out specific sounds. Read more...

This optical microscope image depicts wave motion in a cross-section of the tectorial membrane, part of the inner ear. This membrane is a microscale gel, smaller in width than a single human hair, and it plays a key role in stimulating sensory receptors of the inner ear. Waves traveling on this membrane control our ability to separate sounds of varying pitch and intensity.   

IMAGE COURTESY OF MIT'S MICROMECHANICS GROUPv

 

A Paper Diagnostic for Cancer

 

Photo: Bryce Vickmark

MIT professor Sangeeta Bhatia has developed a new paper diagnostic that can detect cancer by identifying biomarkers in the patient's urine.

Cancer rates in developing nations have climbed sharply in recent years, and now account for 70 percent of cancer mortality worldwide. Early detection has been proven to improve outcomes, but screening approaches such as mammograms and colonoscopy, used in the developed world, are too costly to be implemented in settings with little medical infrastructure.  

To address this gap, MIT engineers have developed a simple, cheap, paper test that could improve diagnosis rates and help people get treated earlier. The diagnostic, which works much like a pregnancy test, could reveal within minutes, based on a urine sample, whether a person has cancer. This approach has helped detect infectious diseases, and the new technology allows noncommunicable diseases to be detected using the same strategy.

The technology, developed by MIT professor and Howard Hughes Medical Institute investigator Sangeeta Bhatia, relies on nanoparticles that interact with tumor proteins called proteases, each of which can trigger release of hundreds of biomarkers that are then easily detectable in a patient’s urine.

Robert Langer wins 2014 Breakthrough Prize in Life Sciences

 

Institute Professor Robert Langer was one of six scientists honored with the 2014 Breakthrough Prize in Life Sciences, which recognizes excellence in research aimed at curing intractable diseases and extending human life. Each award included a $3 million prize, with the “aim of providing the recipients with more freedom and opportunity to pursue even greater future accomplishments.”

“Scientists should be celebrated as heroes, and we are honored to be part of today’s celebration of the newest winners of the Breakthrough Prize in Life Sciences,” said Anne Wojcicki and Sergey Brin, two of the award founders. Other founders include Silicon Valley entrepreneurs Jack Ma, founder of Alibaba Group, and his wife, Cathy Zhang; technology investor Yuri Milner and his wife, Julia; and Mark Zuckerberg and his wife, Priscilla Chan. Langer was honored for his “discoveries leading to the development of controlled drug-release systems and new biomaterials," according to the prize. Read more...

 

 

Encapsulate This

 

Arturo Vegas hits the play button on his tablet computer. A video pops up showing the inside of a monkey's abdomen. “You see this blistering?” asks Vegas, a chemist at the Massachusetts Institute of Technology (MIT) in Cambridge. He points to the lining of the abdominal cavity onto which hundreds of tiny balls resembling semi-translucent fish eggs are attached. “Those are all capsules, and what we're trying to do here is wash them out with a saline solution.” A large needle comes into view and squirts the capsules with fluid in an effort to retrieve them for analysis. They don't budge.

Insulin-producing islet cells could hold the secret to curing type 1 diabetes—if only scientists could figure out a way to encapsulate and transplant them into the body. But first, the right biocompatible material must be found to hold these precious cells. A team of bioengineers thinks it has discovered one. Elie Dolgin reports.

A new way to monitor induced comas
  Automated system could offer better control of patients’ brain states. After suffering a traumatic brain injury, patients are often placed in a coma to give the brain time to heal and allow dangerous swelling to dissipate. These comas, which are induced with anesthesia drugs, can last for days. During that time, nurses must closely monitor patients to make sure their brains are at the right level of sedation — a process that MIT’s Emery Brown describes as “totally inefficient.”  
 

Emery Brown Photo: Bryce Vickmark

Wyss Study Could Be Genetics Breakthrough

A recent study from Harvard’s Wyss Institute for Biologically Inspired Engineering has uncovered features of the genetic code that may end a long-standing controversy in molecular biology and revolutionize the way many drugs and biofuels are currently produced.

Daniel B. Goodman, a graduate student in the HST program, and George M. Church, the Robert Winthrop Professor of Genetics at HMS, led the study.

When rare “words” (codons) are present near the start of bacterial genes, working copies of the gene don’t fold as readily into structures that block protein production. To find out whether the rare words themselves or lack of roadblocks increased protein production, Wyss Institute researchers synthesized 14,000 snippets of DNA with rare codons, roadblocks, both, or neither (individual pixels in this diagram), inserted them into genes, and measured how much protein they produced. Those with rare codons and roadblocks no longer made more protein (green pixels). That showed that rare codons work by removing roadblocks. (Credit: Wyss Institute for Biologically Inspired Engineering at Harvard University)

Sangeeta Bhatia named one of the 10 most influential women in biotech.


Educated at Brown, MIT, Harvard, and Massachusetts General Hospital, Bhatia now runs her own lab at MIT’s Koch Institute for Integrative Cancer Research, overseeing about two dozen researchers.

Among her lab’s projects are designing new kinds of nanoparticles that can accumulate around tumors, penetrate their tough exteriors, and essentially “open the door” so that targeted drugs can more completely destroy the tumors.

 

Pat Greenhouse/Globe Staff

Brain scans may help diagnose dyslexia

 

About 10 percent of the U.S. population suffers from dyslexia, a condition that makes learning to read difficult. Dyslexia is usually diagnosed around second grade, but the results of a new study from MIT could help identify those children before they even begin reading, so they can be given extra help earlier.

The study, done with researchers at Boston Children’s Hospital, found a correlation between poor pre-reading skills in kindergartners and the size of a brain structure that connects two language-processing areas.

 

Research update: New microchip sorts white blood cells from whole blood Device may be used to quickly detect signs of sepsis, other inflammatory diseases.

Early in 2012, MIT scientists reported on the development of a postage stamp-sized microchip capable of sorting cells through a technique, known as cell rolling, that mimics a natural mechanism in the body.

The device successfully separated leukemia cells from cell cultures — but could not extract cells directly from blood.

Now the group has developed a new microchip that can quickly separate white blood cells from samples of whole blood, eliminating any preliminary processing steps — which can be difficult to integrate into point-of-care medical devices.  Read more...

Enhancing RNA interference

Helping RNA escape from cells’ recycling process could make it easier to shut off disease-causing genes.

Nanoparticles that deliver short strands of RNA offer a way to treat cancer and other diseases by shutting off malfunctioning genes. Although this approach has shown some promise, scientists are still not sure exactly what happens to the nanoparticles once they get inside their target cells.

A new study from MIT sheds light on the nanoparticles’ fate and suggests new ways to maximize delivery of the RNA strands they are carrying, known as short interfering RNA (siRNA).

“We’ve been able to develop nanoparticles that can deliver payloads into cells, but we didn’t really understand how they do it,” says Daniel Anderson, the Samuel Goldblith Associate Professor of Chemical Engineering at MIT. “Once you know how it works, there’s potential that you can tinker with the system and make it work better.”

Lipid nanoparticles (carrying siRNA) are shown as they are transported inside cells using endocytic vesicles.
Image: Daria Alakhova and Gaurav Sahay

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