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Scooped by Dr. Stefan Gruenwald!

CRISPR-CAS Could Generate a Hypoallergenic Peanut But Anti-GMO Fear Gets In Its Way

CRISPR-CAS Could Generate a Hypoallergenic Peanut But Anti-GMO Fear Gets In Its Way | Amazing Science |

Anyone with a child in school is probably aware of the need for peanut free zones. You get a notice when your child returns from school on the first day stating that at least one child in their class has a peanut allergy, which means nothing with peanuts gets sent to school for your child’s lunch. If you are a parent of a child with a peanut allergy you understand how important and serious this is – your child is literally one errant Snickers bar away from death.

The general consensus is that food allergies have been on the rise in developed countries, although studies show a wide range of estimates based upon study techniques. A US review found the prevalence of self-reported peanut allergies ranged from 0-2%. A European review found the average estimate to be 2.2% – around 2% is usually the figure quoted. In a direct challenge study, at age 4, 1.1% of the 1218 children were sensitized to peanuts, and 0.5% had had an allergic reaction to peanuts. That means there are millions of people with peanut allergies.

So far there is no cure for the allergies themselves. Acute attacks can be treated with epinephrine, but there are cases of children dying (through anaphylaxis) even after multiple shots. The only real treatment is to obsessively avoid contact with the food in question. Peanuts, tree nuts, and shellfish are the good most likely to cause anaphylaxis.

There is, however, a potential solution. Researchers have been working for year on developing a cultivar of peanut that does not cause allergies. Attempts to achieve this through conventional breeding and hybridization have failed and does not seem likely to succeed. The only real hope of a hypoallergenic peanut is through genetic modification. We are, in fact, on the brink of achieving this goal, but anti-GMO fears are getting in the way.

There are 7 proteins that have been identified in peanuts that cause an allergic reaction. The allergic reaction from peanuts is entirely an IgE mediated Type I hypersensitivity response. The proteins crosslink with the IgE antibodies, which them bind to mast cells and basophils (cells in the immune system) causing a significant inflammatory response that clinically causes the allergic reaction. One peanut contains about 200mg of protein, and as little as 2mg is enough to cause objective symptoms of an allergic reaction.

What makes a food protein an allergen is interesting. About 700 amino acid sequences have been identified that help confer allergenicity to protein. These protein segments allow the protein to survive processing and digestion, and allow the protein to bind to IgE antibodies.

In 2005 a study was published showing that it is possible to silence the gene for the Ara H2 protein, the primary allergenic protein in peanuts. A 2008 follow up by the same team showed decreased allergenicity of the altered peanut. So where are our hypoallergenic peanuts? This is a complicated question, and I don’t think I can give a full answer.

The delay in marketing a hypoallergenic peanut seems to be due partly to technical issues – it turns out to be a lot more difficult to make the necessary changes than at first thought. However, it also seems to be due to the anti-GMO campaign, which has been scaring away investors and making politicians gun-shy.

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Scooped by Dr. Stefan Gruenwald!

How To Detect ANY Virus In A Patient's Blood

How To Detect ANY Virus In A Patient's Blood | Amazing Science |

Better diagnosis leads to better treatment – that’s well-known. Easier said than done, of course, since that’s not always possible when tests for diseases or infections take time to generate results, for example, or are inaccurate or insensitive. Take viruses: There is an abundance out there capable of causing disease, many of which can present similar symptoms or, perhaps worse, none at all. Detection can, therefore, be a bit of a nightmare, sometimes demanding a labor-intensive and costly suite of tests to get to the bottom of a case.

What if there was a universal, one-size-fits-all-test that could pick up any known virus in a sample, eliminating this time-consuming detective work? That might sound quite out of our clutches, but researchers at Washington University School of Medicine might just have achieved this long-awaited, eyebrow-raising feat.

“With this test, you don’t have to know what you’re looking for,” senior author Gregory Storch said in a statement. “It casts a broad net and can efficiently detect viruses that are present at very low levels. We think the test will be especially useful in situations where a diagnosis remains elusive after standard testing or in situations in which the cause of a disease outbreak is unknown.”

Describing their work in Genome Research, the results are pretty impressive. To make their “ViroCap,” the researchers began by creating a broad panel of sequences to be targeted by the test, which they generated using unique stretches of DNA or RNA found in viruses across 34 different human- and animal-infecting families. This resulted in millions of stretches of nucleic acid that can be used to capture matching strands in a sample, should they be present.

But the broad spectrum of this test is not its only remarkable quality: It’s so sensitive that it can even pick up slight variations in sequences, meaning that a virus’ subtype can also be identified – a feature not possible with many traditional tests. Although that wouldn’t necessarily change the way a patient is treated, it could aid disease surveillance.

To demonstrate its capabilities, the researchers took samples from a small group of patients at St. Louis Children’s Hospital and compared the results to those obtained from standard tests. While traditional sequencing managed to find viruses in the majority of the children, ViroCap also managed to pick up some common viruses that it had failed to detect. These included a flu virus and the virus responsible for chickenpox. In a second test run on a different group of children displaying fevers, the new test found an additional seven viruses to the 11 that the traditional testing managed to detect.  

All of this sounds great on paper, but of course it is not yet ready to be used in the clinic. Further trials are required first to check its accuracy on larger groups of people, as so far only a limited number of patients have been screened. But when the time comes, the team plans to make it widely available, which would be welcome in the face of outbreaks like Ebola. Furthermore, the team ultimately hopes to tweak it so that it can detect genetic material from other microbes, like bacteria. If that’s possible, we could have a seriously useful machine on our hands that could change diagnostic medicine for the better. 

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Scooped by Dr. Stefan Gruenwald!

Team succeeds in producing photoreceptors from human embryonic stem cells

Team succeeds in producing photoreceptors from human embryonic stem cells | Amazing Science |

Age-related macular degeneration (AMRD) could be treated by transplanting photoreceptors produced by the directed differentiation of stem cells, thanks to findings published today by Professor Gilbert Bernier of the University of Montreal and its affiliated Maisonneuve-Rosemont Hospital. ARMD is a common eye problem caused by the loss of cones. Bernier's team has developed a highly effective in vitro technique for producing light sensitive retina cells from human embryonic stem cells. "Our method has the capacity to differentiate 80% of the stem cells into pure cones," Professor Gilbert explained. "Within 45 days, the cones that we allowed to grow towards confluence spontaneously formed organised retinal tissue that was 150 microns thick. This has never been achieved before."

In order to verify the technique, Bernier injected clusters of retinal cells into the eyes of healthy mice. The transplanted photoreceptors migrated naturally within the retina of their host. "Cone transplant represents a therapeutic solution for retinal pathologies caused by the degeneration of photoreceptor cells," Bernier explained. "To date, it has been difficult to obtain great quantities of human cones." His discovery offers a way to overcome this problem, offering hope that treatments may be developed for currently non-curable degenerative diseases, like Stargardt disease and ARMD. "Researchers have been trying to achieve this kind of trial for years," he said. "Thanks to our simple and effective approach, any laboratory in the world will now be able to create masses of photoreceptors. Even if there's a long way to go before launching clinical trials, this means, in theory, that will be eventually be able to treat countless patients."

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Scooped by Dr. Stefan Gruenwald!

Alternative CRISPR system could improve genome editing, make it simpler and more exact

Alternative CRISPR system could improve genome editing, make it simpler and more exact | Amazing Science |

The CRISPR/Cas9 technique is revolutionizing genetic research: Scientists have already used it to engineer crops, livestock andeven human embryos, and it may one day yield new ways to treat disease.

But now one of the technique's pioneers thinks that he has found a way to make CRISPR even simpler and more precise. In a paper published in Cell on 25 September, a team led by synthetic biologist Feng Zhang of the Broad Institute in Cambridge, Massachusetts, reports the discovery of a protein1 called Cpf1 that may overcome one of CRISPR-Cas9’s few limitations; although the system works well for disabling genes, it is often difficult to truly edit them by replacing one DNA sequence with another.

The CRISPR/Cas9 system evolved as a way for bacteria and archaea to defend themselves against invading viruses. It is found in a wide range of these organisms, and uses an enzyme called Cas9 to cut DNA at a site specified by 'guide' strands of RNA. Researchers have turned CRISPR/Cas9 into a molecular-biology powerhouse that can be used in other organisms. The cuts made by the enzyme are repaired by the cell’s natural DNA-repair processes.

CRISPR is much simpler than previous gene-editing methods, but Zhang thought there was still room for improvement. So he and his colleagues searched the bacterial kingdom to find an alternative to the Cas9 enzyme commonly used in laboratories. In April, they reported that they had discovered a smaller version of Cas9 in the bacterium Staphylococcus aureus2. The small size makes the enzyme easier to shuttle into mature cells — a crucial destination for some potential therapies. The team was also intrigued by Cpf1, a protein that looks very different from Cas9, but is present in some bacteria with CRISPR. The scientists evaluated Cpf1 enzymes from 16 different bacteria, eventually finding two that could cut human DNA.

They also uncovered some curious differences between how Cpf1 and Cas9 work. Cas9 requires two RNA molecules to cut DNA; Cpf1 needs only one. The proteins also cut DNA at different places, offering researchers more options when selecting a site to edit. “This opens up a lot of possibilities for all the things we could not target before,” says epigeneticist Luca Magnani of Imperial College London.

Cpf1 also cuts DNA in a different way. Cas9 cuts both strands in a DNA molecule at the same position, leaving behind what molecular biologists call ‘blunt’ ends. But Cpf1 leaves one strand longer than the other, creating a 'sticky' end. Blunt ends are not as easy to work with: a DNA sequence could be inserted in either end, for example, whereas a sticky end will only pair with a complementary sticky end. “The sticky ends carry information that can direct the insertion of the DNA,” says Zhang. “It makes the insertion much more controllable.”

Zhang’s team is now working to use these sticky ends to improve the frequency with which researchers can replace a natural DNA sequence. Cuts left by Cas9 tend to be repaired by sticking the two ends back together, in a relatively sloppy repair process that can leave errors. Although it is possible that the cell will instead insert a designated, new sequence at that site, that kind of repair occurs at a much lower frequency. Zhang hopes that the unique properties of how Cpf1 cuts may be harnessed to make such insertions more frequent.

For Bing Yang, a plant biologist at the Iowa State University in Ames, this is the most exciting aspect of Cpf1. “Boosting the efficiency would be a big step for plant science,” he says. “Right now, it is a major challenge.”

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Rescooped by Dr. Stefan Gruenwald from DNA & RNA Research!

Protein-based sensor could detect viral infection or kill cancer cells

Protein-based sensor could detect viral infection or kill cancer cells | Amazing Science |

MIT biological engineers have developed a modular system of proteins that can detect a particular DNA sequence in a cell and then trigger a specific response, such as cell death. This system can be customized to detect any DNA sequence in a mammalian cell and then trigger a desired response, including killing cancer cells or cells infected with a virus, the researchers say.

“There is a range of applications for which this could be important,” says James Collins, the Termeer Professor of Medical Engineering and Science in MIT’s Department of Biological Engineering and Institute of Medical Engineering and Science (IMES). “This allows you to readily design constructs that enable a programmed cell to both detect DNA and act on that detection, with a report system and/or a respond system.”

Collins is the senior author of a Sept. 21 Nature Methods paper describing the technology, which is based on a type of DNA-binding proteins known as zinc fingers. These proteins can be designed to recognize any DNA sequence. “The technologies are out there to engineer proteins to bind to virtually any DNA sequence that you want,” says Shimyn Slomovic, an IMES postdoc and the paper’s lead author. “This is used in many ways, but not so much for detection. We felt that there was a lot of potential in harnessing this designable DNA-binding technology for detection.”

Via Integrated DNA Technologies
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UK scientists seek permission to genetically modify human embryos with CRISPR-CAS

UK scientists seek permission to genetically modify human embryos with CRISPR-CAS | Amazing Science |

Researchers apply for licence months after Chinese team become first to announce they have altered DNA.  Scientists in Britain have applied for permission to genetically modify human embryos as part of a research project into the earliest stages of human development.

The work marks a controversial first for the UK and comes only months after Chinese researchers became the only team in the world to announce they had altered the DNA of human embryos. Kathy Niakan, a stem cell scientist at the Francis Crick Institute in London, has asked the government’s fertility regulator for a licence to perform so-called genome editing on human embryos. The research could see the first genetically modified embryos in Britain created within months.

Donated by couples with a surplus after IVF treatment, the embryos would be used for basic research only. They cannot legally be studied for more than two weeks or implanted into women to achieve a pregnancy.

Though the modified embryos will never become children, the move will concern some who have called for a global moratorium on the genetic manipulation of embryos, even for research purposes. They fear a public backlash could derail less controversial uses of genome editing, which could lead to radical new treatments for disease.

Niakan wants to use the procedure to find genes at play in the first few days of human fertilization, when an embryo develops a coating of cells that later form the placenta. The basic research could help scientists understand why some women lose their babies before term.

The Human Fertilisation and Embryology Authority (HFEA) has yet to review her application, but is expected to grant a licence under existing laws that permit experiments on embryos provided they are destroyed within 14 days. In Britain, research on embryos can only go ahead under a licence from an HFEA panel that deems the experiments to be justified.

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Rescooped by Dr. Stefan Gruenwald from Synthetic Biology!

Taking synthetic biology to next level with engineered multicellular cooperation

Taking synthetic biology to next level with engineered multicellular cooperation | Amazing Science |

HARDER, better, faster, stronger. When cells cooperate, they achieve the otherwise impossible, something that could eventually lead to smart cancer therapies.

Instead of engineering cells to work as tiny individuals, researchers are working on a new class of cellular machines that “talk” to each other – and behave in more sophisticated ways. Put simply, synthetic biology is going multicellular.

“Initially, there was more emphasis on engineering individual cells and real progress was made,” says Ron Weiss at the Massachusetts Institute of Technology. “But now there are an increasing number of demonstrations showing what’s possible with multiple cells. It’s another dimension.”

The latest example comes from a team led by Matthew Bennett at Rice University in Houston, Texas. They developed a system that at its simplest encourages cooperation between two distinct populations of Escherichia coli. One produces an “activator” signalling molecule that triggers the bacteria in the second population to produce a “repressor”. This signal can travel the other way and turn off production of the activating molecule

The team also engineered the E. coli so they would fluoresce depending on the strength of the signals. What’s interesting is the sophisticated way the two populations respond. They found that about every two hours, the cells in both populations fluoresced more and more, before gradually fading away again

Via Marko Dolinar
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The revolution will not be crystallized: a new method sweeps through structural biology

The revolution will not be crystallized: a new method sweeps through structural biology | Amazing Science |

In a basement room, deep in the bowels of a steel-clad building in Cambridge, a major insurgency is under way.

A hulking metal box, some three meters tall, is quietly beaming terabytes’ worth of data through thick orange cables that disappear off through the ceiling. It is one of the world’s most advanced cryo-electron microscopes: a device that uses electron beams to photograph frozen biological molecules and lay bare their molecular shapes. The microscope is so sensitive that a shout can ruin an experiment, says Sjors Scheres, a structural biologist at the UK Medical Research Council Laboratory of Molecular Biology (LMB), as he stands dwarfed beside the £5-million (US$7.7-million) piece of equipment. “The UK needs many more of these, because there’s going to be a boom,” he predicts.

In labs around the world, cryo-electron microscopes such as this one are sending tremors through the field of structural biology. In the past three years, they have revealed exquisite details of protein-making ribosomes, quivering membrane proteins and other key cell molecules, discoveries that leading journals are publishing at a rapid clip. Structural biologists say — without hyperbole — that their field is in the midst of a revolution: cryo-electron microscopy (cryo-EM) can quickly create high-resolution models of molecules that have resisted X-ray crystallography and other approaches, and labs that won Nobel prizes on the back of earlier techniques are racing to learn this upstart method. The new models reveal precisely how the essential machinery of the cell operates and how molecules involved in disease might be targeted with drugs.

“There’s a huge range of very important biological problems that are now open to being tackled in a way that they could never before,” says David Agard, a structural cell biologist at the University of California, San Francisco.

Scheres was recruited to the LMB several years ago to help push cryo-EM technology to its limits — and he and his colleagues have done just that. Last month, they reported one of the burgeoning field’s most impressive feats: a startlingly clear picture of an enzyme implicated in Alzheimer’s disease, showing the position of its 1,200 or so amino acids down to a resolution of a few tenths of a nanometer1

Biologists are now pushing the technique further to deduce ever more detailed structures of small and shape-shifting molecules — a challenge even for cryo-EM. “Whether you call it revolution or a quantum leap, the fact is that the gates have opened,” says Eva Nogales, a structural biologist at the University of California, Berkeley.

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Rapid adoption of CRISPR/Cas9 technology is changing our ability to explore genomics and treat genetic diseases

Rapid adoption of CRISPR/Cas9 technology is changing our ability to explore genomics and treat genetic diseases | Amazing Science |
Rapid adoption of CRISPR/Cas9 technology is changing our ability to explore genomics and treat genetic diseases.

CRISPRs—clustered regularly interspaced short palindromic repeats—are segments of DNA that in 1987 were discovered intermingled in the genetic code of bacteria. Found to correspond to stored remnants of viral DNA, they were later determined to be part of primitive bacterial immune systems. RNA templates transcribed from the CRISPR regions are closely associated with an enzyme known as CRISPR-associated protein 9, or Cas9. If the RNA template finds a match in a viral invader’s DNA, the enzyme chops up the DNA to destroy it.

In the same way, CRISPR/Cas9 can be paired with locations in any genome for use as an editing tool. In 2012, Jennifer Doudna of the University of California, Berkeley; her collaborator Emmanuelle Charpentier, then at Umeå University in Sweden; and coworkers showed they could use a guide RNA (gRNA) sequence to direct Cas9 to targeted sites within prokaryotes, single-cell organisms without a nucleus, and precisely cut the cell’s DNA.

In 2013, Feng Zhang of the Broad Institute of MIT & Harvard, George Church of Harvard University, and Doudna’s group separately showed that the system could edit DNA in eukaryotes, or animal cells, including human ones. It was an early step toward the goal of using the technology to modify genes to treat genetic causes of disease.

By 2014, groups led by Zhang and Doudna had deciphered the structure and inner workings of Cas9. Researchers also have been creating and optimizing gRNAs and tinkering with Cas9 enzymes from different bacterial sources to find the most efficient and precise combinations.

Until CRISPR/Cas9, genome-editing tools were beyond the reach of most researchers. Two existing approaches, zinc finger nucleases (ZFNs) and transcription-activator-like effector nucleases (TALENs), require designing site-specific binding and cutting proteins for every gene target. In contrast, CRISPR/Cas9 uses the same cutting protein regardless of the target. And targeting any gene sequence simply requires synthesizing a matching gRNA of about 20 bases to direct Cas9 to the site.

With this capability, a researcher can use a single gRNA to make one cut to deactivate gene function. With two precise cuts using two gRNAs, along with natural cellular repair mechanisms, researchers can remove, repair, or insert genetic information. Multiple gRNAs open the door to simultaneously changing multiple genes.

Scientists quickly began using the technology to more easily decipher the function of all parts of the genome and to explore disease states. They have used CRISPR/Cas9 to edit genes in insects, plants, fish, rodents, and monkeys. Severe combined immunodeficiency disease, sickle-cell anemia, and cystic fibrosis are already being targeted.

At the Broad Institute, a program called the Genetic Perturbation Platform engineers and uses CRISPR/Cas9 to probe the biology of cells. UC Berkeley and UC San Francisco launched the Innovative Genomics Initiative (IGI) in 2014 to promote genome-editing technology across academic and commercial communities. And the individual labs of Doudna, Zhang, and Charpentier, who is now at Germany’s Helmholtz Centre for Infection Research, are running neck and neck to further develop the technology.

Highlights in the short history of CRISPR/Cas9

◾ Clustered regularly interspaced short palindromic repeats (CRISPRs) are described (J. Bacteriol., 169, 5429)

◾ CRISPRs are recognized as present throughout prokaryotes (Mol. Microbiol., DOI: 10.1046/j.1365-2958.2000.01838.x)

◾ The name CRISPR is coined; CRISPR-associated (Cas) genes are defined (Mol. Microbiol., DOI: 10.1046/j.1365-2958.2002.02839.x)

◾ CRISPRs are found to contain viral sequences; adaptive immune function is proposed (Multiple references)

◾ CRISPRs are found to act in bacterial immune systems (Science, DOI: 10.1126/science.1138140)

◾ CRISPR/Cas cleaves target DNA (Nature, DOI:10.1038/nature09523)

◾ Guide RNA processing is deciphered (Nature, DOI:10.1038/nature09886)
◾ CRISPR systems are modular and can be expressed in other organisms (Nucleic Acids Res., DOI:10.1093/nar/gkr606)
◾ Caribou Biosciences is founded

◾ Cas9 is characterized as an RNA-guided DNA endonuclease (Science, DOI: 10.1126/science.1225829)
◾ Doudna and Charpentier, Zhang file for patents

◾ Site-specific Cas9 genome engineering is done in eukaryotic cells (Science, DOI: 10.1126/science.1231143and 10.1126/science.1232033eLife, DOI:10.7554/elife.00471)
◾ CRISPR Therapeutics is founded
◾ Editas Medicine is founded

◾ Genetic screen in human cells is done using CRISPR/Cas9 (Science, DOI: 10.1126/science.1246981and 10.1126/science.1247005)
◾ Crystal structures of Cas9 endonucleases are resolved (Science, DOI: 10.1126/science.1247997)
◾ Crystal structure of Cas9 in complex with guide RNA and target DNA is found (Cell, DOI:10.1016/j.cell.2014.02.001Nature, DOI:10.1038/nature13579)
◾ Intellia Therapeutics is founded
◾ Broad Institute/Zhang receive first patent

◾ University of California Regents request patent-interference proceeding

Via Integrated DNA Technologies, Jocelyn Stoller
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Scooped by Dr. Stefan Gruenwald!

Biodegradable DNA nanoparticles rapidly penetrate mucus barrier for inhaled lung gene therapy

Biodegradable DNA nanoparticles rapidly penetrate mucus barrier for inhaled lung gene therapy | Amazing Science |

A number of lung diseases are resistant to, or only marginally handled by, conventional therapies. Thanks to the discovery of numerous genetic targets, gene therapy provides an alternative or complementary therapeutic option. Over the past two decades or more, a large number of gene delivery systems, based on viruses or man-made nanoparticles, have been developed in order to deliver therapeutic nucleic acids to the target cells in the lung, while preventing these cargos from being degraded by the body's protective enzymes before they reach the target. However, while it is readily accessible via inhalation, the mucus lining the lung airways typically traps inhaled foreign matter that is then removed from the lung by being rapidly and continuously swept up towards the larynx to be swallowed into the stomach and degraded. Although this is a critical host defense mechanism, the same airway mucus also traps inhaled therapeutic nanoparticles, such as gene delivery systems, through steric obstruction and/or adhesive interactions, meaning that therapeutic nanoparticles trapped in airway mucus will be rapidly cleared from the lung and so not be able to reach their target cells in the lung. Indeed, several clinically tested viral and non-viral gene delivery systems have been shown unable to efficiently penetrate human airway mucus. In addition, the physiological environment in the lung renders it hard to retain stability of therapeutic nanoparticles until they reach the target cells. Thus, despite over two decades of effort, therapeutically effective lung gene therapy is yet to be realized.

Scientists at the Center for Nanomedicine at Johns Hopkins University School of Medicine, Baltimore have previously shown that dense surface coatings with hydrophilic (readily absorbing or dissolving in water) and uncharged polyethylene glycol (PEG) polymers render the particle surface muco-inert (that is, resistant to being trapped by mucus via adhesive interactions). However, achieving the high PEG densities required for efficient mucus penetration while retaining the stability of gene delivery nanoparticles is challenging. Recently, however, the same researchers developed a simple strategy using a blend of highly PEGylated and non-PEGylated polymers at an optimal ratio to formulate mucus-penetrating DNA nanoparticles (DNA-MPPs) capable of retaining stability in physiological environments as well as rapidly penetrating human airway mucus.

Dr. Jung Soo Suk discussed the paper that he, Prof. Justin Hanes, Dr. Panagiotis Mastorakos and their colleagues published in Proceedings of the National Academy of Sciences. "Non-viral gene delivery systems, being devoid of one or more of shortcomings of virus-based vectors, constitute an attractive alternative for inhaled gene therapy," Suk tells Medical Xpress. (These systems are typically made with natural or synthetic materials possessing a large number of positive charges that interact with negatively charged nucleic acids to form small nanoparticles – a process known as complexation.) "In particular, biodegradable cationic," or positively charged, "polymers provide a superior in vivo safety profile compared to non-biodegradable or slowly degrading systems while providing timely release of nucleic acid payloads that may lead to improved gene delivery efficacy – both features being due to their hydrolytic nature." Hydrolysis is a chemical process of decomposition involving the splitting of a bond and the addition of the hydrogen cation and the hydroxide anion of water.

However, Suk points out, surfaces of these conventionally designed systems are, typically, positively charged, which makes them unlikely not only to retain their colloidal stability in physiological environments, but also to efficiently penetrate negatively charged biological barriers, such as airway mucus, due to the electrostatically-driven adhesive interactions. "Here," he explains, "we engineered a biodegradable polymer-based platform addressing these problems, thereby leading to highly efficient gene transfer to the lung in vivo, surpassing leading non-viral platforms, including a clinically tested system – and perhaps viral vectors as well."

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The tiniest Lego: a tale of nanoscale motors, rotors, switches and pumps

The tiniest Lego: a tale of nanoscale motors, rotors, switches and pumps | Amazing Science |
The robot moves slowly along its track, pausing regularly to reach out an arm that carefully scoops up a component. The arm connects the component to an elaborate construction on the robot's back. Then the robot moves forward and repeats the process — systematically stringing the parts together according to a precise design.

It might be a scene from a high-tech factory — except that this assembly line is just a few nanometres long. The components are amino acids, the product is a small peptide and the robot, created by chemist David Leigh at the University of Manchester, UK, is one of the most complex molecular-scale machines ever devised.

It is not alone. Leigh is part of a growing band of molecular architects who have been inspired to emulate the machine-like biological molecules found in living cells — kinesin proteins that stride along the cell's microscopic scaffolding, or the ribosomethat constructs proteins by reading genetic code. Over the past 25 years, these researchers have devised an impressive array of switches, ratchets, motors, rods, rings, propellers and more — molecular mechanisms that can be plugged together as if they were nanoscale Lego pieces. And progress is accelerating, thanks to improved analytical-chemistry tools and reactions that make it easier to build big organic molecules.

Now the field has reached a turning point. “We've made 50 or 60 different motors,” says Ben Feringa, a chemist at the University of Groningen in the Netherlands. “I'm less interested in making another motor than actually using it.”

That message was heard clearly in June, when one of the influential US Gordon conferences focused for the first time on molecular machines and their potential applications, a clear sign that the field has come of age, says the meeting's organizer, chemist Rafal Klajn of the Weizmann Institute of Science in Rehovot, Israel. “In 15 years' time,” says Leigh, “I think they will be seen as a core part of chemistry and materials design.”

Getting there will not be easy. Researchers must learn how to make billions of molecular machines work in concert to produce measurable macroscopic effects such as changing the shape of a material so that it acts as an artificial muscle. They must also make the machines easier to control, and ensure that they can carry out countless operations without breaking.

That is why many in the field do not expect the first applications to involve elaborate constructs. Instead, they predict that the basic components of molecular machines will be used in diverse areas of science: as light-activated switches that can release targeted drugs, for example, or as smart materials that can store energy or expand and contract in response to light. That means that molecular architects need to reach out to researchers who work in fields that might benefit from their machine parts, says Klajn. “We need to convince them that these molecules are really exciting.”

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How to build tiny models of human tissues, called organoids, more precisely than ever before

How to build tiny models of human tissues, called organoids, more precisely than ever before | Amazing Science |

A UCSF-led team has developed a technique to build tiny models of human tissues, called organoids, more precisely than ever before using a process that turns human cells into a biological equivalent of LEGO bricks. These mini-tissues in a dish can be used to study how particular structural features of tissue affect normal growth or go awry in cancer. They could be used for therapeutic drug screening and to help teach researchers how to grow whole human organs.

The new technique — called DNA Programmed Assembly of Cells (DPAC) and reported in the journal Nature Methods on Aug. 31 — allows researchers to create arrays of thousands of custom-designed organoids, such as models of human mammary glands containing several hundred cells each, which can be built in a matter of hours.

There are few limits to the tissues this technology can mimic, said Zev Gartner, PhD, the paper’s senior author and an associate professor of pharmaceutical chemistry at UCSF. “We can take any cell type we want and program just where it goes. We can precisely control who’s talking to whom and who’s touching whom at the earliest stages. The cells then follow these initially programmed spatial cues to interact, move around, and develop into tissues over time.”

“One potential application,” Gartner said, “would be that within the next couple of years, we could be taking samples of different components of a cancer patient’s mammary gland and building a model of their tissue to use as a personalized drug screening platform. Another is to use the rules of tissue growth we learn with these models to one day grow complete organs.”

Our bodies are made of more than 10 trillion cells of hundreds of different kinds, each of which plays its unique role in keeping us alive and healthy. The way these cells organize themselves structurally in different organ systems helps them coordinate their amazingly diverse behaviors and functions, keeping the whole biological machine running smoothly. But in diseases such as breast cancer, the breakdown of this order has been associated with the rapid growth and spread of tumors.

“Cells aren’t lonely little automatons,” Gartner said. “They communicate through networks to make group decisions. As in any complex organization, you really need to get the group’s structure right to be successful, as many failed corporations have discovered. In the context of human tissues, when organization fails, it sets the stage for cancer.”

But studying how the cells of complex tissues like the mammary gland self-organize, make decisions as groups, and break down in disease has been a challenge to researchers. The living organism is often too complex to identify the specific causes of a particular cellular behavior. On the other hand, cells in a dish lack the critical element of realistic 3-D structure.

“This technique lets us produce simple components of tissue in a dish that we can easily study and manipulate,” said Michael Todhunter, PhD, who led the new study with Noel Jee, PhD, when both were graduate students in the Gartner research group. “It lets us ask questions about complex human tissues without needing to do experiments on humans.”

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Scientists Mimic Sharkskin to Develop Bacteria-Resistant Surfaces

Scientists Mimic Sharkskin to Develop Bacteria-Resistant Surfaces | Amazing Science |
Smooth diamond shape texture of sharkskin appears to be a very hostile environment for micro-organisms.

Even though hospitals are rapidly cleaned with strong antiseptics, they can still be filled with all sorts of microorganisms that threaten our health. About two million people catch some disease in US hospitals every year, and around 100,000 die from it, while microorganisms tend to grow more resilient to antibiotics.  Scientists are trying to mimic nature to find a long-term solution for this issue, and they allegedly found it in sharks skin, WIRED Science reported.

While helping the NAVY figure out how to keep its ship sides smooth, scientist Anthony Brennan studied sharkskin. Its smooth surface allows these great sea predators to swim faster than any other sea creature. He noticed that sharkskin is barnacle and algae-free. It is also a well known fact that microorganisms are more likely to hold onto roughened surfaces than stick onto smooth ones. That is how Sharklet Technologies was created.

According to Sharklet Technologies CEO Mark Spiecker, “By staying clean while moving slow, sharks defy a basic principle of the ocean.” Sharkskin consists of millions of nano-ridges, arranged in a diamond pattern. This texture enables the process called mechanotransduction, which basically provides mechanical stress on microorganisms. In such an environment, bacteria lives no longer than 18 minutes, which is not enough lifetime for reproduction, according to Spiecker.

The goal is the creation of a thin film that has the same texture as sharkskin, that can be applied on hospital’s most exposed surfaces such as door handles or stairway banisters. This should make it more difficult for bacteria to build up on such surfaces, including antibiotic-resistant bacteria, like MRSA—to settle on these areas and infect hospital patients.

WIRED reported Spieckers claim that the Sharklet film can reduce bacteria transfer up to a 97 percent.

Via CineversityTV
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DNA ‘vaccine’ that sterilizes mice, could lead to one-shot birth control

DNA ‘vaccine’ that sterilizes mice, could lead to one-shot birth control | Amazing Science |

Animal birth control could soon be just a shot away: A new injection makes male and female mice infertile by tricking their muscles into producing hormone-blocking antibodies. If the approach works in dogs and cats, researchers say, it could be used to neuter and spay pets and to control reproduction in feral animal populations. A similar approach could one day spur the development of long-term birth control options for humans.

“This looks incredibly promising,” says William Swanson, director of animal research at the Cincinnati Zoo and Botanical Garden in Ohio. “We’re all very excited about this approach; that it’s going to be the one that really works.”

For decades, the go-to methods for controlling animal reproduction have been spay or neuter surgeries. But the surgeries, which require animals to be anesthetized, can be expensive—one reason so many dogs and cats remain unfixed and feral animal populations continue to grow. Nearly 2.7 million dogs and cats were euthanized in U.S. shelters last year. A cheaper, faster method of sterilization is considered a holy grail for animal population control. 

To get there, researchers have already created vaccines that trigger an immune response in animals. This response produces antibodies that block gonadotropin-releasing hormone (GnRH), required by all mammals to turn on the pathways that spur egg or sperm development. The vaccines in this class—including deer contraceptive GonaCon—have been shown to effectively work as both male and female birth control in animals. But, like many human immunizations, the vaccines rely on an immune response that eventually dwindles away, forcing the use of booster shots every few years.

Biologist Bruce Hay of the California Institute of Technology in Pasadena and colleagues took a different approach to blocking GnRH. Rather than rely on animals’ immune systems to create antibodies, he and his colleagues engineered a piece of DNA that—when packaged inside inactive virus shells and injected into mice—turned their muscle cells into anti-GnRH antibody factories. Because muscle cells are some of the longest lasting in the body, they continue to churn out the antibodies for 10 or more years. Both male and female mice with high enough levels of the antibodies were rendered completely infertile when Hay’s team allowed them to mate 2 months later, the team reports online today in Current Biology.

Via Integrated DNA Technologies
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Gene-editing record smashed in pigs: 60 genes edited

Gene-editing record smashed in pigs: 60 genes edited | Amazing Science |

Researchers modify more than 60 genes in effort to enable organ transplants into humans.

For decades, scientists and doctors have dreamed of creating a steady supply of human organs for transplantation by growing them in pigs. But concerns about rejection by the human immune system and infection by viruses embedded in the pig genome have stymied research. Now, bymodifying more than 60 genes in pig embryos — ten times more than have been edited in any other animal — researchers believe they may have produced a suitable non-human organ donor.

The work was presented on 5 October 2015 at a meeting of the US National Academy of Sciences (NAS) in Washington DC on human gene editing. Geneticist George Church of Harvard Medical School in Boston, Massachusetts, announced that he and colleagues had used the CRISPR/Cas9 gene-editing technology to inactivate 62 porcine endogenous retroviruses (PERVs) in pig embryos. These viruses are embedded in all pigs’ genomes and cannot be treated or neutralized.It is feared that they could cause disease in human transplant recipients.

Church’s group also modified more than 20 genes in a separate set of pig embryos, including genes that encode proteins that sit on the surface of pig cells and are known to trigger a human immune response or cause blood clotting. Church declined to reveal the exact genes, however, because the work is as yet unpublished.Eventually, pigs intended for organ transplants would need both these modifications and the PERV deletions.

Via Integrated DNA Technologies
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BGI is planning to sell their gene-edited 'micropigs' as pets

BGI is planning to sell their gene-edited 'micropigs' as pets | Amazing Science |

Cutting-edge gene-editing techniques have produced an unexpected byproduct — tiny pigs that a leading Chinese genomics institute will soon sell as pets.

BGI in Shenzhen, the genomics institute that is famous for a series of high-profile breakthroughs in genomic sequencing, originally created the micropigs as models for human disease, by applying a gene-editing technique to a small breed of pig known as Bama. On 23 September 2015, at the Shenzhen International Biotech Leaders Summit in China, BGI revealed that it would start selling the pigs as pets. The animals weigh about 15 kilograms when mature, or about the same as a medium-sized dog.

At the summit, the institute quoted a price tag of 10,000 yuan (US$1,600) for the micropigs, but that was just to "help us better evaluate the market”, says Yong Li, technical director of BGI’s animal-science platform. In future, customers will be offered pigs with different coat colors and patterns, which BGI says it can also set through gene editing.

With gene editing taking biology by storm, the field's pioneers say that the application to pets was no big surprise. Some also caution against it. “It's questionable whether we should impact the life, health and well-being of other animal species on this planet light-heartedly,” says geneticist Jens Boch at the Martin Luther University of Halle-Wittenberg in Germany. Boch helped to develop the gene-editing technique used to create the pigs, which uses enzymes known as TALENs (transcription activator-like effector nucleases) to disable certain genes.

How to regulate the various applications of gene-editing is an open question that scientists are already discussing with agencies across the world. BGI agrees on the need to regulate gene editing in pets as well as in the medical research applications that make up the core of its micropig activities. Any profits from the sale of pets will be invested in this research. “We plan to take orders from customers now and see what the scale of the demand is,” says Li.

The decision to sell the pigs as pets surprised Lars Bolund, a medical geneticist at Aarhus University in Denmark who helped BGI to develop its pig gene-editing programme, but he admits that they stole the show at the Shenzhen summit. “We had a bigger crowd than anyone,” he says. “People were attached to them. Everyone wanted to hold them.”

They could meet a preexisting demand. In the United States, for instance, reports have surfaced of people who wanted a porcine lap pet, but were disappointed when animals touted as 'teacup' pigs weighing only 5 kilograms grew into 50-kilogram animals. Genetically-edited micropigs stay reliably small, the BGI team says.

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A plasmonic nanorod that walks on DNA origami

A plasmonic nanorod that walks on DNA origami | Amazing Science |

Researchers from the Max Planck Institute for Intelligent Systems in Stuttgart have developed a gold nanocylinder equipped with discrete DNA strands as ‘feet’ that can walk across a DNA origami platform. They are able to trace the movements of the nanowalker, which is smaller than the optical resolution limit, by exciting plasmons in the gold nanocylinder. Plasmons are collective oscillations of numerous electrons. The excitation changes the ray of light, thus allowing the researchers to actually observe the nanowalker. Their main objective is to use such mobile plasmonic nanoobjects to study how miniscule particles interact with light.

Nanomachines – i.e. mechanical devices with dimensions of nanometers – could one day carry out specific tasks in fields such as medicine, information processing, chemistry or scientific research, according to nanotechnology experts.

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The Genesis Engine: Can we eliminate disease and solve world hunger?

The Genesis Engine: Can we eliminate disease and solve world hunger? | Amazing Science |

SPINY GRASS AND SCRAGGLY PINES creep amid the arts-and-crafts buildings of the Asilomar Conference Grounds, 100 acres of dune where California's Monterey Peninsula hammerheads into the Pacific. It's a rugged landscape, designed to inspire people to contemplate their evolving place on Earth. So it was natural that 140 scientists gathered here in 1975 for an unprecedented conference.

They were worried about what people called “recombinant DNA,” the manipulation of the source code of life. It had been just 22 years since James Watson, Francis Crick, and Rosalind Franklin described what DNA was—deoxyribonucleic acid, four different structures called bases stuck to a backbone of sugar and phosphate, in sequences thousands of bases long. DNA is what genes are made of, and genes are the basis of heredity.

Preeminent genetic researchers like David Baltimore, then at MIT, went to Asilomar to grapple with the implications of being able to decrypt and reorder genes. It was a God-like power—to plug genes from one living thing into another. Used wisely, it had the potential to save millions of lives. But the scientists also knew their creations might slip out of their control. They wanted to consider what ought to be off-limits.

By 1975, other fields of science—like physics—were subject to broad restrictions. Hardly anyone was allowed to work on atomic bombs, say. But biology was different. Biologists still let the winding road of research guide their steps. On occasion, regulatory bodies had acted retrospectively—after Nuremberg, Tuskegee, and the human radiation experiments, external enforcement entities had told biologists they weren't allowed to do that bad thing again. Asilomar, though, was about establishing prospective guidelines, a remarkably open and forward-thinking move.

Fast forward to 2015. Baltimore joined 17 other researchers for another California conference, this one at the Carneros Inn in Napa Valley. “It was a feeling of déjà vu,” Baltimore says. There he was again, gathered with some of the smartest scientists on earth to talk about the implications of genome engineering. The stakes, however, have changed. Everyone at the Napa meeting had access to a gene-editing technique called Crispr-Cas9. The first term is an acronym for “clustered regularly interspaced short palindromic repeats,” a description of the genetic basis of the method; Cas9 is the name of a protein that makes it work. Technical details aside, Crispr-Cas9 makes it easy, cheap, and fast to move genes around—any genes, in any living thing, from bacteria to people. “These are monumental moments in the history of biomedical research,” Baltimore says. “They don't happen every day.”

Using the three-year-old technique, researchers have already reversed mutations that cause blindness, stopped cancer cells from multiplying, and made cells impervious to the virus that causes AIDS. Agronomists have rendered wheat invulnerable to killer fungi like powdery mildew, hinting at engineered staple crops that can feed a population of 9 billion on an ever-warmer planet. Bioengineers have used Crispr to alter the DNA of yeast so that it consumes plant matter and excretes ethanol, promising an end to reliance on petrochemicals. Startups devoted to Crispr have launched.

International pharmaceutical and agricultural companies have spun up Crispr R&D. Two of the most powerful universities in the US are engaged in a vicious war over the basic patent. Depending on what kind of person you are, Crispr makes you see a gleaming world of the future, a Nobel medallion, or dollar signs.

The technique is revolutionary, and like all revolutions, it's perilous. Crispr goes well beyond anything the Asilomar conference discussed. It could at last allow genetics researchers to conjure everything anyone has ever worried they would—designer babies, invasive mutants, species-specific bioweapons, and a dozen other apocalyptic sci-fi tropes. It brings with it all-new rules for the practice of research in the life sciences. But no one knows what the rules are—or who will be the first to break them.

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Scientists find a way to perform genome engineering and gene regulation at the same time

Scientists find a way to perform genome engineering and gene regulation at the same time | Amazing Science |

The CRISPR-Cas9 system has been in the limelight mainly as a revolutionary genome engineering tool used to modify specific gene sequences within the vast sea of an organism’s DNA. Cas9, a naturally occurring protein in the immune system of certain bacteria, acts like a pair of molecular scissors to precisely cut or edit specific sections of DNA. More recently, however, scientists have also begun to use CRISPR-Cas9 variants as gene regulation tools to reversibly turn genes on or off at whim.

Both of these tasks, genome engineering and gene regulation, are initiated with a common step: the Cas9 protein is recruited to targeted genes by the so-called matching sequences of "guide RNA" that help Cas9 latch on to specific sequences of DNA in a given genome. But until now, genome engineering and gene regulation required different variants of the Cas9 protein; while the former task hinges on Cas9’s innate DNA-cleaving activity, the latter has been achieved by engineered Cas9 variants that have had their DNA-cleaving "fangs" removed, but still retain their ability to latch onto a specific genomic target. These latter Cas9 variants are commonly fused with proteins that regulate gene expression.

Now, using a new approach developed by researchers led by George Church, Ph.D., of Harvard and Ron Weiss, Ph.D., of the Massachusetts Institute of Technology, both tasks can be achieved using one type of Cas9, allowing scientists to increase the complexity of gene editing functions and their overall control of genes. The method opens up unexpected possibilities for understanding diseases and drug mechanisms. The study’s findings are reported in the September 7 issue of Nature Methods.

Key to their strategy, the team discovered that the length of the guide RNA sequence plays a critical role in determining whether or not Cas9 will solely bind to DNA or if it will excise it as well. "We decided to systematically test why it was that truncating guides too much caused Cas9 to no longer cut the intended genomic site," said Alejandro Chavez, Postdoctoral Fellow at the Wyss Institute. Chavez, who is advised by both Church and Collins at the Wyss, is a co-first author on the study together with Samira Kiani, Postdoctoral Associate in Weiss’ MIT lab.

The Wyss and MIT team confirmed in human cells that shorter guide RNAs indeed no longer allowed Cas9 to cut a targeted gene. To their surprise, however, the shorter guide RNAs did not prevent Cas9 from efficiently binding to that target, opening up the possibility for scientists to attach gene regulation proteins to Cas9 for delivery to specific genes.

"By using our uncovered guide RNA principles, we can now for the first time toggle a single protein to gain direct control over both, gene sequences and gene expression, and turn almost any DNA sequence into a regulatory sequence to further bend the cell to our will. We envision future uses for the technology that can help decipher the tangled web of interactions underlying for example cancer drug resistance and stem cell differentiation, or design advanced synthetic gene circuitries," said Church, Core Faculty member at Harvard’s Wyss Institute for Biologically Inspired Engineering, Robert Winthrop Professor of Genetics at Harvard Medical School and Professor of Health Sciences and Technology at Harvard and MIT.

"This new functionality will improve our ability to decipher the complex relationships between interdependent genes responsible for many diseases," said Marcelle Tuttle, a Research Fellow at the Wyss Institute and co-author on the study. The findings could also be used in large scale metabolic production of chemicals and fuels using genetically engineered bacteria – such as common E. coli – while safeguarding the "microbial workers" from infection by other microbes and pathogens.

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Scientists produce cancer drug (etoposide) from rare plant in the lab for the first time

Scientists produce cancer drug (etoposide) from rare plant in the lab for the first time | Amazing Science |
Six enzymes from mayapple that complete the biosynthetic pathway to the etoposide aglycone

Stanford scientists produced a common cancer drug – previously only available from an endangered plant – in a common laboratory plant. This work could lead to a more stable supply of the drug and allow scientists to manipulate that drug to make it even safer and more effective.

Many of the drugs we take today to treat pain, fight cancer or thwart disease were originally identified in plants, some of which are endangered or hard to grow. In many cases, those plants are still the primary source of the drug.

Now Elizabeth Sattely, an assistant professor of chemical engineering at Stanford, and her graduate student Warren Lau have isolated the machinery for making a widely used cancer-fighting drug from an endangered plant. They then put that machinery into a common, easily grown laboratory plant, which was able to produce the chemical. The technique could potentially be applied to other plants and drugs, creating a less expensive and more stable source for those drugs.

"People have been grinding up plants to find new chemicals and testing their activity for a really long time," Sattely said. "What was striking to us is that with a lot of the plant natural products currently used as drugs, we have to grow the plant, then isolate the compound, and that's what goes into humans."

In her work, published Sept. 10 in the journal Science, Sattely and her team used a novel technique to identify proteins that work together in a molecular assembly line to produce the cancer drug. Her group then showed that the proteins could produce the compound outside the plant – in this case, they had put the machinery in a different plant, but they hope to eventually produce the drug in yeast. Either the plant or yeast would provide a controlled laboratory environment for producing the drug.

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J. Craig Venter: Humans now have the ability to control evolution, though perhaps not yet the wisdom

J. Craig Venter: Humans now have the ability to control evolution, though perhaps not yet the wisdom | Amazing Science |

J. Craig Venter is the pioneering cartographer of the human genome, the sequence of which he and other scientists mapped in 2000. The WorldPost recently spoke with this modern Prometheus about the promises and perils of being able to read, write and edit the human genome.

Venter: "Biological evolution has taken three and a half or four billion years to get us where we are. Social evolution has been much faster. Now that we can read and write the genetic code, put it in digital form and translate it back into synthesized life, it will be possible to speed up biological evolution to the pace of social evolution. On a theoretical basis, that gives us control over biological design. We can write DNA software, boot it up to a converter and create unlimited variations on biological life."

Venter: "This year is the fifth anniversary of when my team produced the first synthetic cell. To do that, we took the ones and zeroes in the computer, rewrote the genetic code from four bottles of chemicals and booted that up to get a self-replicating cell. That means we now have the power to start controlling evolution.

We’re doing this now in cells that can change manufacturing and create a new industrial revolution by creating synthetic food, chemicals and even building materials. Ultimately, as we begin to better understand our own genetic code, we can edit the human genome -- as some Chinese scientists disturbingly did earlier this year.

So we have the power to do it. But we clearly do not have the wisdom to do it or the knowledge to do it in a safe fashion. That is why many of us involved in the science have suggested a moratorium on any human changes until we understand the full consequences of our interventions. 

In the end, however, it is inevitable that we will not be able to control ourselves. Using knowledge to eliminate horrific diseases from the population is going to be an overwhelming temptation. The flip side of eliminating disease will also be irresistible because we have learned now how to improve intelligence and how to improve athletic abilities -- in short, how to make better people."

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Making nanowires from protein and DNA

Making nanowires from protein and DNA | Amazing Science |

The ability to custom design biological materials such as protein and DNA opens up technological possibilities that were unimaginable just a few decades ago. For example, synthetic structures made of DNA could one day be used to deliver cancer drugs directly to tumor cells, and customized proteins could be designed to specifically attack a certain kind of virus. Although researchers have already made such structures out of DNA or protein alone, a Caltech team recently created--for the first time--a synthetic structure made of both protein and DNA. Combining the two molecule types into one biomaterial opens the door to numerous applications.

A paper describing the so-called hybridized, or multiple component, materials appears in the September 2 issue of the journal Nature ("Computational design of co-assembling protein-DNA nanowires").

There are many advantages to multiple component materials, says Yun (Kurt) Mou (PhD '15), first author of the Nature study. "If your material is made up of several different kinds of components, it can have more functionality. For example, protein is very versatile; it can be used for many things, such as protein-protein interactions or as an enzyme to speed up a reaction. And DNA is easily programmed into nanostructures of a variety of sizes and shapes.

"But how do you begin to create something like a protein-DNA nanowire--a material that no one has seen before? Mou and his colleagues in the laboratory of Stephen Mayo, Bren Professor of Biology and Chemistry and the William K. Bowes Jr. Leadership Chair of Caltech's Division of Biology and Biological Engineering, began with a computer program to design the type of protein and DNA that would work best as part of their hybrid material. "Materials can be formed using just a trial-and-error method of combining things to see what results, but it's better and more efficient if you can first predict what the structure is like and then design a protein to form that kind of material," he says.

The researchers entered the properties of the protein-DNA nanowire they wanted into a computer program developed in the lab; the program then generated a sequence of amino acids (protein building blocks) and nitrogenous bases (DNA building blocks) that would produce the desired material.

However, successfully making a hybrid material is not as simple as just plugging some properties into a computer program, Mou says. Although the computer model provides a sequence, the researcher must thoroughly check the model to be sure that the sequence produced makes sense; if not, the researcher must provide the computer with information that can be used to correct the model. "So in the end, you choose the sequence that you and the computer both agree on. Then, you can physically mix the prescribed amino acids and DNA bases to form the nanowire."

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Self-targeting blocks malaria parasite invasion

Self-targeting blocks malaria parasite invasion | Amazing Science |

The development of drug resistance is a major problem in combating malaria caused by Plasmodium falciparum, the most deadly human malaria parasite. Resistance to artemisinin, the key component of current treatment regimens, is now being reported in parts of Asia. Recently Zenonos et al. report that it is possible to prevent parasite proliferation and clear a malaria infection using chimeric antibodies specific for a key host molecule required for parasite invasion of erythrocytes. Targeting a host protein rather than the parasite itself is much less likely to lead to the development of resistance, a problem that plagues treatments for virtually all infectious diseases.

In their study, Zenonos et al. generated recombinant chimeric antibodies with high affinity for the human erythrocyte surface receptor basigin. P. falciparum parasites bind to basigin as they invade erythrocytes, and this binding appears to be essential for parasite proliferation. The recombinant antibodies block this key interaction, prevent erythrocyte invasion, and thus disrupt the replicative cycle that is crucial for the maintenance of an infection. Using a humanized mouse model, the authors showed that treatment with these antibodies leads to rapid clearance of an infection with no sign of recurrence.

The strategy of targeting host proteins raises obvious concerns about toxicity and side effects of the therapy. In the case of basigin, these concerns are somewhat alleviated by previous work using anti-basigin antibodies as therapies for cancer and graft-versus-host disease, which were well tolerated. However, the authors reduced the likelihood of side effects by using chimeric antibodies that incorporated the human IgG1 and constant kappa chains, thus reducing the possibility of anti-mouse antibody responses. Further, they included an established set of mutations in the constant heavy chains that inhibit complement and Fcγ-receptor binding, thus significantly reducing the possibility of antibody effector functions targeted to the erythrocyte surface. The chimeric antibodies are therefore thought to disrupt parasite proliferation solely by blocking basigin–parasite binding.

Malaria parasites, like most infectious organisms, have demonstrated a remarkable ability to develop resistance to widely used therapies. This raises the disturbing possibility that parasites resistant to all known therapies could develop in the near future, a predicament that is now confronting the tuberculosis community. By expanding our list of potential targets for disease intervention to several key host molecules—the first time this has been successfully demonstrated for malaria—we can potentially create new therapies that are less vulnerable to the rapid generation of resistance.

Via Denis Hudrisier
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Microalgae Biofuels Market Rapidly Grows

Microalgae Biofuels Market Rapidly Grows | Amazing Science |

Algae, which causes a lot of damage to the marine ecosystem by creating water blooms and red tides, is now turning into the next-generation raw material of eco-friendly biofuels, including biodiesel and bioethanol.

Until now, biofuels have been produced from first-generation grass feed stock, such as corn and sugar cane, or second-generation plant feed stock, including corn stalk and rice husks. However, using grass feed stock aggravates shortages of food among low-income groups by raising the price of grain, while plant feed stock has limitations like low yields. As a third-generation raw material that will overcome such weak points, marine algae and microalgae are in the spotlight from the global biofuels industry.

In particular, they absorb carbon dioxide in the process of growth. So, when marine algae and microalgae are provided carbon dioxide emitted from thermal power plants and breweries, they can reduce carbon dioxide emissions and produce biofuels at the same time. According to a survey, 180 tons of carbon dioxide are decreased when producing 100 tons of microalgae.

Sohn Jong-koo, senior researcher at the Industry Information Analysis Center at KISTI, said, “Currently, the U.S. accounts for 50 percent of the algae biofuel market, while Europe accounts for 30 percent. Korea, Japan, China, Australia and Israel are now going after them.” Sohn expects that the related market will be created in earnest, beginning this year, as commercial plants will be constructed in earnest. In fact, market research firm Pike Research has forecasted that the algae biofuel market this year will be estimated at US$1.6 billion (1.88 trillion won), and it will rapidly grow by 812 percent in the next five years to reach US$13 billion (15.3 trillion won) in 2020. It means that 61 million gallons, or 230 million liters, of algae biofuels will be sold around the world five years after that.

In a bid to tap into such a huge market, South Korean government-funded research institutes and private firms are advancing technology based on government-level support. The country is aiming to construct 500,000 hectares of marine algae farms by 2020 and produce 227 million liters of bioethanol annually, taking over 20 percent of domestic gasoline consumption.

Via Marko Dolinar
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Slow-melting ice cream ingredient discovered by scientists

Slow-melting ice cream ingredient discovered by scientists | Amazing Science |
A new ingredient developed by scientists in Scotland could mean that ice cream fans can enjoy their treats before they melt.

A naturally occurring protein can be used to create ice cream which stays frozen for longer in hot weather. The scientists estimate that the slow-melting product could become available in three to five years. The development could also allow products to be made with lower levels of saturated fat and fewer calories.

Teams at the Universities of Edinburgh and Dundee have discovered that the protein, known as BsIA, works by binding together the air, fat and water in ice cream. It is also said to prevent gritty ice crystals from forming - ensuring a fine, smooth texture.

Prof Cait MacPhee, of the University of Edinburgh's school of physics and astronomy, who led the project, said: "It's not completely non-melting because you do want your ice cream to be cold. It will melt eventually but hopefully by keeping it stable for longer it will stop the drips."

Deanna 's comment, September 8, 4:48 PM
i liked this story but...why 3-5 years? and how much slower would this ice cream melt? also would this new ice cream taste the same?