Amazing Spider Silk properties will lead to the creation of artificial muscles

Our muscles are amazing structures. With the trigger of a thought, muscle filaments slide past each other and bundles of contracting fibers pull on the bones moving our bodies. The triggered stretching behavior of muscle is inherently based in geometry, characterized by a decrease in length and increase in volume (or vice versa) in response to a change in the local environment, such as humidity or heat.

Variations of this dynamic geometry appear elsewhere in nature, exhibiting a variety of mechanisms and structures and inspiring development in artificial muscle technology. 

Spider silk, specifically Ornithoctonus Huwena spider silk, now offers the newest such inspiration thanks to research from a collaboration of scientists in China and the U.S., the results of which are published today in Applied Physics Letters, from AIP Publishing.

Credit: British Tarantula Society

"Spider silk is a natural biological material with high sensitivity to water, which inspires us to study about the interaction between spider silk and water," said Hongwei Zhu, a professor in Tsinghua University's School of Material Science and Engineering in Beijing and part of the collaboration. "Ornithoctonus Huwena spider is a unique species as it can be bred artificially and it spins silk of nanoscale diameter."

Besides the shrink-stretch ability of muscles, the way in which the motion is triggered -- how the muscle is actuated -- is a key part of its functionality. These spider silk fibers, actuated by water droplets, showed impressive behavior in all the ways that matter to muscle performance (or to super heroes that may need them to swing from buildings).

"In this work, we reveal the 'shrink-stretch' behavior of the Ornithoctonus Huwena spider silk fibers actuated by water, and successfully apply it on weight lifting," said Zhu. "The whole process can cover a long distance with a fast speed and high efficiency, and further be rationalized through an analysis of the system's mechanical energy."

The research team looked at the actuation process in a few different scenarios, capturing the macro dynamics of the flexing fibers with high speed imaging. They actuated bare fibers on a flat surface (a microscope slide) and while dangling from a fixed point (held with tweezers) before adding a weight to the dangling configuration to test its lifting abilities.

Zhu and his group also investigated the micro structure of the proteins that make up the fibers, revealing the protein infrastructure that leads to its hydro-reflexive action.

Electron microscopy gave a clear picture of the smooth inner threads that make up the fibrous structure, and a laser-driven technique, called Raman spectroscopy, revealed the precise conformation of the protein folding structures making up each layer. Fundamentally, the specific molecular configurations, in this case having proteins that have a strong affinity for water and that rearrange in the presence of water, give rise to the spider silk's actuation.

"Alpha-helices and beta-sheets are two types of secondary protein folding structures in spider silk proteins," said Zhu. "Beta-sheets act as crosslinks between protein molecules, which are thought relevant to the tensile strength of spider silk. A-helices are polypeptide chains folded into a coiled structure, which are thought relevant to the extensibility and elasticity in spider silk protein."

Returning the fiber back to its relaxed state (as one-use muscles are far less useful) requires only removing the water, which offers conservation along with its simplicity. With some fine tuning, there is also potential for designing the precise behavior of the shrink-stretch cycle.

"In addition, as the falling water droplet can be collected and recycled, the lifting process is energy-saving and environmentally friendly," said Zhu. "This has provided the possibility that the spider silk can act as biomimetic muscle to fetch something with low energy cost. It can be further improved to complete staged shrink-stretch behavior by designing the silk fiber's thickness and controlling droplet's volume."

Understanding this remarkable material offers new insight for developing any of a number of drivable, flexible devices in the future.

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Scientists have created new forms of life containing '' Artificial DNA'' This could be the beginning of a whole new life form.

Credit: Kateryna Kon

Scientists have engineered the first ever 'semi-synthetic' organisms, by breeding E. coli bacteria with an expanded, six-letter genetic code.

While every living thing on Earth is formed according to a DNA code made up of four bases (represented by the letters G, T, C and A), these modified E. coli carry an entirely new type of DNA, with two additional DNA bases, X and Y, nestled in their genetic code.

The team, led by Floyd Romesberg from the Scripps Research Institute in California, engineered synthetic nucleotides - molecules that serve as the building blocks of DNA and RNA - to create an additional base pair, and they’ve successfully inserted this into the E. coli’s genetic code.

Credit: samsunkenthaber

Now we have the world’s first semi-synthetic organism, with a genetic code made up of two natural base pairs and an additional 'alien' base pair, and Romesberg and his team suspect that this is just the beginning for this new form of life.

"With the virtually unrestricted ability to maintain increased information, the optimised semi-synthetic organism now provides a suitable platform  to create organisms with wholly unnatural attributes and traits not found elsewhere in nature," the researchers report.

"This semi-synthetic organism constitutes a stable form of semi-synthetic life, and lays the foundation for efforts to impart life with new forms and functions."

Back in 2014, the team announced that they had successfully engineered a synthetic DNA base pair - made from molecules referred to as X and Y - and it could be inserted into a living organism.


Since then, they’ve been working on getting their modified E. coli bacteria to not only take the synthetic base pair into their DNA code, but hold onto it for their entire lifespan.

Initially, the engineered bacteria were weak and sickly, and would die soon after they received their new base pair, because they couldn’t hold onto it as they divided.

Credit: Wonderwhizkids

"Your genome isn't just stable for a day," says Romesberg. "Your genome has to be stable for the scale of your lifetime. If the semisynthetic organism is going to really be an organism, it has to be able to stably maintain that information."

Over the next couple of years, the team devised three methods to engineer a new version of the E. coli bacteria that would hold onto their new base pair indefinitely, allowing them to live normal, healthy lives.

The first step was to build a better version of a tool called a nucleotide transporter, which transports pieces of the synthetic base pair into the bacteria’s DNA, and inserts it into the right place in the genetic code. 

"The transporter was used in the 2014 study, but it made the semisynthetic organism very sick," explains one of the team, Yorke Zhang.

Once they’d altered the transporter to be less toxic, the bacteria no longer had an adverse reaction to it.

Next, they changed the molecule they’d originally used to make the Y base, and found that it could be more easily recognised by enzymes in the bacteria that synthesise DNA molecules during DNA replication.

Finally, the team used the revolutionary gene-editing tool, CRISPR-Cas9 to engineer E. coli that don’t register the X and Y molecules as a foreign invader.

The researchers now report that the engineered E. coli are healthy, more autonomous, and able to store the increased information of the new synthetic base pair indefinitely.

"We've made this semisynthetic organism more life-like," said Romesberg.

If all of this is sounding slightly terrifying to you, there's been plenty of concern around the potential impact that this kind of technology could have.


Back in 2014, Jim Thomas of the ETC Group, a Canadian organisation that aims to address the socioeconomic and ecological issues surrounding new technologies, told the New York Times:

"The arrival of this unprecedented 'alien' life form could in time have far-reaching ethical, legal, and regulatory implications. While synthetic biologists invent new ways to monkey with the fundamentals of life, governments haven’t even been able to cobble together the basics of oversight, assessment or regulation for this surging field."

And that was when the bacteria were barely even functioning. 

But Romesberg says there's no need for concern just yet, because for one, the synthetic base pair is useless. It can't be read and processed into something of value by the bacteria - it's just a proof-of-concept that we can get a life form to take on 'alien' bases and keep them.

The next step would be to insert a base pair that is actually readable, and then the bacteria could really do something with it.

The other reason we don't need to be freaking out, says Romesberg, is that these molecules have not been designed to work at all in complex organisms, and seeing as they're like nothing found in nature, there's little chance that this could get wildly out of hand.

"[E]volution works by starting with something close, and then changing what it can do in small steps," Romesberg told Ian Sample at The Guardian.

"Our X and Y are unlike natural DNA, so nature has nothing close to start with. We have shown many times that when you do not provide X and Y, the cells die, every time."


Time will tell if he's right, but there's no question that the team is going to continue improving on the technique in the hopes of engineering bacteria that can produce new kinds of proteins that can be used in the medicines and materials of the future.


The research has been published in Proceedings of the National Academy of Sciences.


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The above post is reprinted from materials provided by Sciencealert . Note: Materials may be edited for content and length.

Researchers are close to discover the factor that determined the evolution of life on Earth

Credit: klss/Shutter Stock

Modern science has advanced significantly over the last couple of decades. We’ve managed to answer several of the world’s most long-standing questions, but some answers have continued to elude today’s scientists, including how life first emerged from Earth’s primordial soup.

However, a collaboration of physicists and biologists in Germany may have just found an explanation to how living cells first evolved.

In 1924, Russian biochemist Alexander Oparin proposed the idea that the first living cells could have evolved from liquid droplet protocells.

He believed these protocells could have acted as naturally forming, membrane-free containers that concentrated chemicals and fostered reactions.

Aleksandr Oparin (right) and Andrei Kursanov in the enzymology laboratory, 1938 Credit: wikipedia

In their hunt for the origin of life, a team of scientists from the Max Planck Institute for the Physics of Complex Systems and the Institute of Molecular Cell Biology and Genetics, both in Dresden, drew from Oparin’s hypothesis by studying the physics of 'chemically active' droplets (droplets that cycle molecules from the fluid in which they are surrounded).

Unlike a 'passive' type of droplet - like oil in water, which will just continue to grow as more oil is added to the mix - the researchers realised that chemically active droplets grow to a set size and then divide on their own accord.

This behaviour mimics the division of living cells and could, therefore, be the link between the nonliving primordial liquid soup from which life sprung and the living cells that eventually evolved to create all life on Earth.

"It makes it more plausible that there could have been a spontaneous emergence of life from nonliving soup," said Frank Jülicher, co-author of the study that appeared in the journal Nature Physics in December.

It’s an explanation of "how cells made daughters," said lead researcher David Zwicker. "This is, of course, key if you want to think about evolution."


Add a droplet of life

Some have speculated that these proto-cellular droplets might still be inside our system "like flies in life’s evolving amber".

To explore that hypothesis, the team studied the physics of centrosomes, which are organelles active in animal cell division that seem to behave like droplets.

Zwicker modelled an 'out-of-equilibrium' centrosome system that was chemically active and cycling constituent proteins continuously in and out of the surrounding liquid cytoplasm.

The proteins behave as either soluble (state A) or insoluble (state B).  An energy source can trigger a state reversal, causing the protein in state A to transform into state B by overcoming a chemical barrier. 

As long as there was an energy source, this chemical reaction could happen.

"In the context of early Earth, sunlight would be the driving force," Jülicher said.

Odarin famously believed that lighting strikes or geothermal activity on early Earth could’ve triggered these chemical reactions from the liquid protocells.

This constant chemical influx and efflux would only counterbalance itself, according to Zwicker, when a certain volume was reached by the active droplet, which would then stop growing.

Typically, the droplets could grow to about tens or hundreds of microns, according to Zwicker’s simulations. That’s about the same scale as cells.

The next step is to identify when these protocells developed the ability to transfer genetic information.

Jülicher and his colleagues believe that somewhere along the way, the cells developed membranes, perhaps from the crusts they naturally develop out of lipids that prefer to remain at the intersection of the droplet and outside liquid.

Credit: Lucy Reading-Ikkanda/Quanta Magazine

As a kind of protection for what’s within the cells, genes could’ve begun coding for these membranes. But knowing anything for sure still depends on more experiments.

So, if the very complex life on Earth could have begun from something as seemingly inconspicuous as liquid droplets, perhaps the same could be said of possible extraterrestrial life?

In any case, this research could help us understand how life as we know it started from the simplest material and how the chemical processes that made our lives possible emerged from these.

The energy and time it took for a protocell to develop into a living cell, and the living cells into more complex parts, until finally developing into an even more complex organism is baffling.

The process itself took billions of years to happen, so it’s not surprising we need some significant time to fully understand it.

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The most interesting 10 species of animals in 2016

An international committee of biologists chose the most interesting species described in 2016

The most interesting10 species described in 2016 were designated as "International Institute for Species Exploration" and a committee of biologists and naturalists, in a sort of "competition" designed to attract public attention to the problems of biodiversity conservation.

In a report entitled significantly "SOS. State of Observed Species" by specialists from the "International Institute for Species Exploration" in conjunction with those from the "International Plant Names Index", "Zoological Record" Thomson Reuters, "International Journal of Systematic and Evolutionary Microbiology "," AlgaeBase "" MycoBank "and" World Register of Marine Species "outlined in 2008, the latest year for which complete data in the field, have been described globally 18.225 in 2140 new species living species and fossils.

The winner ten species are:

• Danionella Dracula - a family over ciprinidae.
• Nephila Komaci - the largest of spiders "weavers", with a diameter of 10 cm.
• Chondrocladia (Meliiderma) turbiformis - a "killer sponge" carnivore.
• Swim bombiviridis - a marine worm.
• Aiteng ater - a mollusk. 
• Histiophryne psychedelia - a fish with unusual coloring.
• Drewesii Phallus - a woody fungus.
• Gymnotus omarorum - an electric fish.
• Nepenthes Attenboroughii - a carnivorous plant "twisted".
• Dioscorea orangeana - a new plant tuber.

1. Danionella Dracula - a family over ciprinidae

2. Nephila Komaci the largest of spiders "weavers", with a diameter of 10 cm.

3. Chondrocladia (Meliiderma) turbiformis - a "killer sponge" carnivore.

4. Swim bombiviridis - a marine worm.

5. Aiteng ater - a mollusk. 

6. Histiophryne psychedelia - a fish with unusual coloring.

7. Drewesii Phallus - a woody fungus.

8. Gymnotus omarorum - an electric fish.

9. Nepenthes Attenboroughii - a carnivorous plant "twisted".

10. Dioscorea orangeana - a new plant tuber

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The above post is reprinted from materials provided by Le Scienze  . Note: Materials may be edited for content and length.

There’s A Gene That Reverses Cellular Aging, And Now We Know How

In the biology lab-based equivalent of Indiana Jones and the Last Crusade, researchers from the University at Buffalo have uncovered the human body’s internal fountain of eternal youth, in the form of a gene called NANOG.(Homeobox protein) When expressing this gene in aged stem cells, the team found that it reactivated certain processes that had become exhausted, restoring their ability to develop into fully functioning muscle cells.

As we go about our lives, wear and tear causes the body’s cells to die via a process called senescence. When this occurs, new cells are created from stem cells in order to replace those that have become senescent, although when we hit old age our stem cells become depleted or unable to develop.


Mesenchymal stem cells (MSCs), for example, normally develop into smooth muscle cells (SMCs). However, once we reach a certain age, these MSCs lose their efficacy and start generating SMCs that lack a protein called actin, rendering them unable to contract like healthy muscle tissue should.

A number of mechanisms underlie this demise. For instance, aged MSCs appear to become unresponsive to a growth factor called transforming growth factor beta (TGF-β), while also suffering from a lack of Rho-associated protein kinase (ROCK), which catalyzes the formation of actin fibers.

Without actin, muscle fibers can't contract. Designua/Shutterstock

However, when enhancing the expression of NANOG in aged MSCs, the researchers discovered that both the ROCK and TGF-β pathways were restored. This subsequently kickstarted the production of actin, leading to the creation of fully functioning muscle cells with an ability to contract that matched that of young muscle cells.

To confirm this mode of action, the researchers introduced chemicals to inhibit both ROCK and TGF-β, discovering that this completely blocked the effects of NANOG. A full report of their work can be found in the journal Stem Cells.

Even more amazingly, they then repeated the experiment using stem cells taken from patients suffering from Hutchinson-Gilford progeria syndrome, a genetic disease that causes accelerated cell senescence. In doing so, they found that NANOG once again boosted the production of actin, leading to the development of healthy and fully functional muscle cells.

Based on this discovery, study co-author Stelios Andreadis explained in a statement that “not only does NANOG have the capacity to delay aging, it has the potential in some cases to reverse it.”

Though it is not yet clear how NANOG reinvigorates the ROCK and TGF-β pathways, the researchers insist that targeting this gene could be the key to treating a range of age-related disorders by restoring the regenerative capacity of the body’s aged



Source: iflscience