Scientists develop biological safety lock for containment of modified organisms

It’s been the premise of many a sci-fi/horror movie … a genetically-modified organism is created in the lab to help the human race, but instead it gets loose and wreaks havoc in the outside world. Well, scientists from Harvard and Yale are working to make sure that such a scenario can’t take place – at least, not with one of the bacteria most commonly used in biotech research. Teams from both universities have produced genetically-alteredE. coli bacteria that can’t live without special amino acids, which can only be obtained from a lab.

In separate studies, both teams used an already-modified strain of E. colideveloped by a group led by Harvard’s Prof. George Church. First announced in 2013, it was officially “the world’s first genomically recoded organism.”

Using different methods, the teams further modified that strain to incorporate synthetic amino acids in numerous locations throughout its genome. Although the bacteria relies on these acids in order to survive, it can’t synthesize them on its own, nor can it find them in the environment – only labs working with the modified E. coli can produce the acids.

This means that if the bacteria were to escape from the lab, it wouldn’t survive for long.

While it may be technically possible that the bacteria could evolve a means of synthesizing a substitute for the synthetic amino acids, it’s reportedly highly unlikely. The Harvard E. coli are dependent on the acids as the result of 49 genetic changes, and Church believes that the chances of the bacteria being able to undo all of those changes without also acquiring any harmful mutations is “incredibly slim.”

Additionally, the bacteria developed at Harvard currently rely on three separate amino acids, making survival outside of the lab that much less likely. Church would like to make the technology even safer, by further increasing the number of acids required by the bacteria.

Papers on the Harvard and Yale research were recently published in the journal Nature.

Sources: Harvard University, Yale University

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Nanobot micromotors deliver medical payload in living creature for the first time

Researchers working at the University of California, San Diego have claimed a world first in proving that artificial, microscopic machines can travel inside a living creature and deliver their medicinal load without any detrimental effects. Using micro-motor powered nanobots propelled by gas bubbles made from a reaction with the contents of the stomach in which they were deposited, these miniature machines have been successfully deployed in the body of a live mouse.

The picayune robots used in the research were tubular, about 20 micrometers long, 5 micrometers in diameter, and coated in zinc. Once the mouse ingested these tiny tubes and they reached the stomach, the zinc reacted with the hydrochloric acid in the digestive juices to produce bubbles of hydrogen which then propelled the nanobots along like miniature rockets.

Reaching speeds of up to 60 micrometers per second, the nanobots headed outwards toward the stomach lining where they then embedded themselves, dissolved, and delivered a nanoparticle compound directly into the gut tissue.

According to the researchers, of all the nanobots deployed in the stomach of the mouse, those that reached the stomach walls remained attached to the lining for a full 12 hours after ingestion, thereby proving their effectiveness and robust nature.

Further, after the mouse was eventually euthanized and the stomach was dissected and examined, the presence of the nanobots also showed no signs of raised toxicity levels or tissue damage. According to the researchers this was in line with their expectations, particularly given that zinc is effectively also a multipurpose nutrient.

While nanobots have been used before on organic tissue – such as in thedestruction of the Hepatitis C virus – and still others have been designed to be propelled using external forces within a living creature, the University of California micromachines are the very first self-propelled, nanoparticle delivering nanobots ever. And it is this fact that makes the research team believe that its success so far merits further research and cites the fact that this is now the beginning of a proven method to deliver targeted drug administration.

For everyone else, this is exciting technology that may well help to medically treat human beings in the not-too-distant future. Of course, this is early days in this research and a plethora of continuously successful tests will need to be run before it can even be considered by the likes of the US Food and Drug Administration to approve its use in people. But these first steps are vital in what may one day be a commonplace, targeted, and safe alternative to traditional high-dose medications.

No announcement has been made regarding further tests or the possibility of human-based trials.

The research was published in the journal ACS Nano.

Source: UC, San Diego

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Scientists give graphene one more quality – magnetism

Graphene is extremely strong for its weight, it’s electrically and thermally conductive, and it’s chemically stable … but it isn’t magnetic. Now, however, a team from the University of California, Riverside has succeeded in making it so. The resulting magnetized graphene could have a wide range of applications, including use in “spintronic” computer chips.

While other groups have previously magnetized graphene, they’ve done so by doping it with foreign substances, and the presence of these impurities has negatively affected its electronic properties. In this case, though, the graphene was able to remain pure.

Led by professor of physics and astronomy Jing Shi, the UC Riverside team laid a sheet of regular graphene down on an atomically smooth layer of magnetic yttrium iron garnet. That material then simply magnetized the graphene as it lay against it. Yttrium iron garnet was used due to the fact that certain other magnetic materials could disrupt the graphene’s electrical transport properties.

When the sheet of graphene was removed and subsequently exposed to a magnetic field, it was shown to indeed possess magnetic qualities of its own.

“This is the first time that graphene has been made magnetic this way,” said Shi. “The magnetic graphene acquires new electronic properties so that new quantum phenomena can arise. These properties can lead to new electronic devices that are more robust and multi-functional.”

Those devices could include improved spintronic chips, that use the spin of electrons – which can be magnetically manipulated – to store data.

A paper on the research was recently published in the journal Physical Review Letters.

Source: University of California, Riverside

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Lasers help create water-repelling, light-absorbing, self-cleaning metals

With the help of very high-power laser beams, researchers at the University of Rochester have created micro and nanostructures that turn metals black and make their surfaces very easy to keep clean and dry. The advance could help prevent icing and rust, collect heat more effectively and perhaps even translate to other materials, leading to water-repelling electronics.

There are many super-hydrophobic coatings out there that can quickly and effectively repel water and other liquids to keep metals rust-free and t-shirtspristine. The problem, however, is that they rely on chemicals that can eventually wear off and leave the underlying material at the mercy of the elements.

Professor Chunlei Guo and colleagues at the University of Rochester have found a way to treat metals so that they themselves become permanently averse to water, or super-hydrophobic. They have achieved this with the help of femtosecond lasers, which shoot extremely high-power pulses over a very short time (a femtosecond is a millionth of a billionth of a second). The power is high enough to engrave micro and nanoscale structures into the metal and change its properties at the surface.

The same team had previously used femtosecond lasers to create water-attracting (hydrophilic) metals which were so effective that they made water flow uphill. Now the scientists chose to turn to the complementary problem.

Using powerful 65-femtosecond laser pulses at a rate of up to one thousand per second the scientists were able to change the surface structure of platinum, titanium and brass samples. The structure they produced was an array of microscopic grooves which were then covered by 5 to 10-nanometer features, a design that was partly inspired by the way in which lotus leaves keep water and parasites at bay.

The result is a remarkable material that not only repels water very effectively (tilt the surface by five degrees and the water slides or bounces right off), but is also velvet black from every angle (which makes it highly light-absorbing) and even self-cleaning.

In order to test the self-cleaning properties of their structure, Guo and team took ordinary dust particles from a vacuum cleaner and dumped them on the surface of the treated metals. According to the scientists, three drops of water were enough to remove about half of the dust, and a dozen drops left the surface spotless. In the real world, the materials would be able to clean themselves very effectively as drops if rain, dew or fog fall onto the surface and quickly drag away the dust, leaving it both clean and dry.

There is potential for this technology to make a difference in developing countries, to collect rain water more effectively or to create latrines that are remain clean without flushing, staving off disease. The combined light-absorbing and water-repelling properties could also help make solar thermal collectors that perform consistently and without the need for cleaning.

Guo and team are now investigating how they might apply their technique to non-metallic materials, which could eventually lead to water-repellant electronics. But before this technology can get out in the real world, the researchers will need to look into ways to scale up effectively. As things stand now, it takes one hour to produce a one square inch sample.

The advance appears in the Journal of Applied Physics and is further illustrated in the video below.

Source: University of Rochester

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DNA trax tracks tainted food with molecular bar code

According to the US Center for Disease Control (CDC), 129,000 Americans are sent to hospital and 3,000 die each year from food poisoning. Currently, tracing contaminated food is largely a matter of record keeping and detective work, but Lawrence Livermore National Laboratory (LLNL) researchers, in partnership with DNATrek, have developed DNATrax, a DNA-based additive for directly tracking food from producer to consumer.

Food poisoning due to outbreaks is a major problem, putting thousands of lives at risk, wasting tons of recalled foodstuffs, with US$70 billion dollars lost in the US alone each year. The problem is that current methods of tracing outbreaks are inefficient, time consuming and imprecise because they rely on what is essentially a combination of accountancy, interviews, and logical deduction to trace contaminated foods back along what is often an incomplete trail. That’s where DNATrax comes in

Originally designed for bio-defense work, DNATrax was created as a way to simulate germ warfare attacks on indoor and outdoor targets. The conventional way of determining the weak spots in targets ranging from underground rail systems to the Pentagon is to spray harmless bacteria into the air, later collect samples from various places, then incubate them to see how the bacteria has spread. With DNATrax, the bacteria is replaced by particles of non-biological DNA that can be collected with simple forensic swabs and then subjected to DNA analysis. The application of food tracking was an unexpected bonus.

DNATrax is surprisingly simple. It’s an odorless, tasteless substance that’s classified as a harmless food additive by the US Food and Drug Administration. It’s made of strands of non-living and non-viable DNA encased in sugars similar to common icing sugar. These strands, like all DNA, can record information and have 10⁶⁰ variations, so they can contain a lot of data that, according to LLNL, acts like “an invisible barcode.”

Applying DNATrax is simply a matter of spraying it on fruits, vegetables and meats, or mixing it in with bulk commodities like honey, olive oil, flour, or rice. The idea is to use the DNA to record a code sequence with data such as what the product is, where it came from, when it was harvested and so on. Then simple polymerase chain reaction (PCR) technology can identify the code and reveal the origin of the product in about an hour, right down to which tree a particular apple came from.

Aside from tracking down contaminated food, LLNL says that DNATrax can also help combat food piracy. Most people have heard of movie or music piracy and may have come across a dodgy “Rolex” down the market, but piracy is actually a major problem for almost all commerce – including food. Called wastage, grocery shelves are constantly invaded by everything from fake corn flakes to counterfeit honey selling under false labels, to adulterated wines and olive oils mixing the premium with the cheap stuff. Since such label swapping and adulteration does not occur where the food is produced, but somewhere down the line, DNATrax can identify fraudulent foods as well as how many adulterants have been added, how much, and where they came from.

Another application that LLNL is looking at is protective clothing. With the current Ebola outbreak, tracking contamination in anti-contamination suits is vital, so the researchers see DNATrax as a safe way of assessing how well current suits are performing. By applying the DNA particles to the exterior of the suit, it is possible to identify if a breach has occurred by seeing if contaminants appear on the wearer’s skin.

“We all hear horror stories about contaminated foods,” says DNATrek CEO Anthony Zografos. “We are not prepared to deal with an outbreak of pathogens such as E. coli and salmonella in tainted foods. However, DNATrax is a quick and efficient way to stop these foods from sickening more people and costing producers more money due to massive recalls triggered by poor traceability.”

The video below explains how DNATrax works.

Source: Lawrence Livermore National Laboratory

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First contracting human muscle ever grown in laboratory

Researchers working at Duke University’s Pratt School of Engineering claim to have produced a laboratory first by having grown human muscle tissue that contracts and reacts to stimuli. Electrical pulses, biochemical signals and pharmaceuticals have all been used to produce reactions in the tissue that show it behaves in the same way that natural human muscles does. As a result, laboratory grown tissue may soon provide researchers with the ability to study diseases and assess drugs without invasive procedures on human subjects.

In a study headed by Nenad Bursac, associate professor of biomedical engineering at Duke University, and Lauran Madden, a postdoctoral researcher in Bursac’s laboratory, the team began by using a sample of human cells that had already been grown beyond the stem cell stage, but had not yet formed into muscle tissue. These “myogenic precursors” (that is, cells that will become muscle tissue) were then stretched by the researchers over a supportive scaffolding designed to promote their growth in 3D and to increase their area to more 1,000 times their original size.

Molded from PDMS (silicone), the entire structure was filled with a growth medium that allowed the cells to develop while the structure itself helped to form aligned and functioning muscle fibers. As a result, the team was able to grow around 5 grams of muscle tissue for every 50 mg of donor tissue – a hundred-fold increase in mass.

“We have a lot of experience making bioartifical muscles from animal cells in the laboratory, and it still took us a year of adjusting variables like cell and gel density and optimizing the culture matrix and media to make this work with human muscle cells,” said Madden.

To ascertain how closely it replicated muscle tissue naturally occurring within a human body, Madden peppered the newly-formed muscle tissue with an array of tests. As a result, when electrical stimuli were applied, Madden observed that the muscles strongly contracted in response. As the first human muscle grown in a laboratory to react in this way, further tests also showed that along the entire length of the new tissue pathways for nerves to activate the muscle were also complete and functioning.

The team then turned its attention to finding out if its created muscle could be used as a substitute for human-produced muscle in medical tests. Using a variety of drugs, including cholesterol-lowering statins and a performance-enhancing drug Clenbuterol, a drug notorious for use by some athletes, the team aimed to ascertain the reactions to these drugs in relation to the way naturally-grown muscle reacts.

As it turned out, the effects of these drugs matched the effects documented in human patients. The statins showed a dose-dependent response and the Clenbuterol showed a slim, but beneficial, window for increased contraction. The lab-grown muscle had given a truly human response.

“The beauty of this work is that it can serve as a test bed for clinical trials in a dish. We are working to test drugs’ efficacy and safety without jeopardizing a patient’s health and also to reproduce the functional and biochemical signals of diseases – especially rare ones and those that make taking muscle biopsies difficult,” said Bursac.

“One of our goals is to use this method to provide personalized medicine to patients,” Bursac concluded. “We can take a biopsy from each patient, grow many new muscles to use as test samples and experiment to see which drugs would work best for each person.”

The short video below shows the muscle tissue being stimulated in the laboratory.

The results of this research were published in the journal eLIFE.

Source: Duke University

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Your computer might know you even better than your friends do

New research has found that computers can “judge” personality traits far more precisely than previously thought. The study found that it is possible for computers to draw inferences about a person as accurately as their spouse can. Even then, the judgements were based only on Facebook “likes.”

Jointly run between Stanford University and the University of Cambridge, the study sought to find out how a computer’s answers to questions about an individual would compare to those of their friends and family. A total of 86,220 volunteers provided answers to questions about themselves regarding the five basic personality dimensions of openness, conscientiousness, extraversion, agreeableness and neuroticism. A standard, 100-item long personality questionnaire was used to gather the data.

Friends and family of each volunteer were then asked to provide their judgement of the individual’s personality based on their existing knowledge of the person, via a 10-item questionnaire. The same questions were put to a computer model that answered them based on the analysis of what articles, videos, artists and other items the volunteers had “liked” on Facebook.

The relationship of human respondents to the volunteers was categorized under titles including colleague, friend, roommate, family-member or spouse. It was found that the computer model was able to more accurately predict answers of the volunteers than a colleague by analyzing 10 likes, than a friend or a roommate with 70 likes, than a family-member with 150 likes and than a spouse with 300 likes.

“This is an emphatic demonstration of the ability of a person’s psychological traits to be discovered by an analysis of data, not requiring any person-to-person interaction,” the researchers noted. “It shows that machines can get to know us better than we’d previously thought, a crucial step in interactions between people and computers.”

Co-lead author and postdoctoral fellow at Stanford’s Department of Computer Science Michal Kosinski suggests that computers have a number of advantages over humans where personality analysis is concerned. In particular, he says, they are able to retain, access and analyze large quantities of data in ways that humans are not optimized to do.

A paper on the research was recently published in the journal Proceedings of the National Academy of Sciences of the United States of America.

Source: Stanford University

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Harvard coloring tech could be an attractive alternative to paint

Most people probably don’t think of a coating of paint as being a particularly major component of a manufactured item. If the object is quite large, however, or if a lot of them are being made, paint can add considerably to its weight and/or production costs. With that in mind, researchers from Harvard University’s Laboratory for Integrated Science and Engineering have created a new lightweight, low-cost coloring technology for both rough and smooth surfaces.

Developed by PhD student Mikhail Kats and his advisor Prof. Federico Capasso, the process involves using a machine known as an electron-beam evaporator to vaporize pieces of metal, by striking them with a stream of electrons. The vapor travels upwards through a vacuum chamber within the evaporator, and collects on the surface of a metallic item placed at the top (if the item isn’t metallic, an initial base layer of vaporized metal vapor can first be applied). By repeating this process, multiple layers can be deposited on the item.

What results is an ultra-thin coating. Due to the nature in which that coating scatters reflected light, it appears to the human eye as a given color – exactly which color depends upon the metals used, and the ratios in which they’re applied.

In a test of the technology, Kats coated a piece of paper with a film made up of gold and germanium. While a previous study had shown that the technique worked on smooth surfaces, this was the first time that it had been successfully applied to a rough surface.

The paper remained flexible, even after the coating was applied. Although the color appeared basically the same when viewed from different angles, the “hills and valleys” within its microstructure added some subtle variation to the light-scattering process. This caused it to have a somewhat pearlescent appearance, which could be desirable in many applications. Using a different application technique, however, the color could be made to appear completely uniform from any angle.

Although gold is an expensive metal, very little of it was required. Additionally, a number of other metals can be used, including not only germanium but also aluminum. “This is a way of coloring something with a very thin layer of material, so in principle, if it’s a metal to begin with, you can just use 10 nanometers to color it, and if it’s not, you can deposit a metal that’s 30 nm thick and then another 10 nm,” said Kats. “That’s a lot thinner than a conventional paint coating that might be between a micron and 10 microns thick.”

According to the university, the technology could be used to color virtually any material, including those that are rough or flexible. Additionally, because the coatings absorb a lot of light, they could find their way into optoelectronic devices such as photodetectors and solar cells.

Source: Harvard University

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Super-sensitive motion sensor could be used to hunt for extraterrestrial life

People often state that certain planets are too hot, cold or toxic to support life. The catch, however, is that those people are really just talking about life as we know it here on Earth. By that same token, when rovers exploring other planets seek out chemical signatures associated with life forms, they’re only able to identify chemicals that we know to look for. That’s why Swiss scientists from the EPFL research center have created a device that identifies microscopic life, based on nanoscale movements instead of chemistry.

Developed by researchers Giovanni Dietler, Sandor Kasas and Giovanni Longo, the ultra-sensitive motion sensor utilizes technology that’s already used in the atomic force microscope.

In the case of the microscope, a tiny sharp-tipped probe is moved across the surface being imaged. That probe takes the form of a cantilever – one end is secured to the microscope, while the other (the pointy end) is free to move up and down as it’s affected by the contours and other properties of the surface. The microscope uses a laser to measure those minuscule movements, and proceeds to create an image of the surface based upon them.

On the EPFL motion sensor, a tiny cantilever extends out horizontally from the device. When microscopic living items such as individual cells or bacterium are placed on its free end, even their regular metabolic functions will cause the cantilever to vibrate. As with the microscope, those movements are detected via a laser.

When testing the system, the scientists were able to detect movement in items such as bacteria, yeast, mouse and human cells. They were also able to detect and isolate organisms from soil and water samples, which stopped producing readings once drugs were used to kill them.

In the immediate future, suggested applications for the technology include things like drug development. For that particular scenario, live bacteria or cancer cells could be placed on a cantilever and then subjected to a medication intended to eradicate them – the sensor would let researchers know how thoroughly the medication did its job.

Down the road, however, the EPFL team would indeed like to see arrays of the motion sensors installed on vehicles like the Curiosity Rover, helping to search for extraterrestrial life. That’s assuming that life forms on other planets do move, even if just a little bit.

A paper on the research was recently published in the journal Proceedings of the National Academy of Sciences.

Source: EPFL

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