One set of researchers from the Max Planck Institute for Extraterrestrial Physics are trialling a device for quickly disinfecting human skin using low-temperature plasma, which would save a significant amount of time, compared to traditional hospital scrubbing.

The second is an "argon plasma torch", developed with ADTEC Plasma Technology Ltd in Japan, for disinfecting chronic non-healing wounds. This terrifying sounding device can specifically target bacteria but is harmless to human cells.

MRSA (Methicillin-resistant Staphylococcus aureus) arose as such a threat because it is mutation that is resistant all but the most powerful antibiotics. It can prove lethal if it spreads to your heart or other key organs. But finding stronger treatments against MRSA may not be the best long-term solution — by attacking the bugs with plasma, we may ensure that the mutations that survive will be even tougher. We're effectively breeding Fremen bacteria.

[via the Institute of Physics]

University of Arizona biologist Anna Himler orginally began studying the ants, called Mycocepurus smithii, because they had incredible success as farmers. Many breeds of ant keep domesticated "farms" where they breed various kinds of fungus for nourishment. But Mycocepurus smithii was able to breed fungus far more successfully, and in greater varieties, than other ants Himler had encountered.

As she and her team studied the insects, they realized there were no male ants anywhere to be found. Himler told the BBC that it's possible the ants evolved so as "not to operate under the usual constraints of sexual reproduction." Interestingly, the fungi that the ants cultivate also reproduce asexually. But why would these ants choose to emulate the reproductive cycle favored by their crops? Himler explains:

It avoids the energetic cost of producing males, and doubles the number of reproductive females produced each generation from 50% to 100% of the offspring.

All the members of the colony are clones of the queen. While that means the queen can control every aspect of the population, it also makes the colony vulnerable to pandemics. A virus that can kill one ant can kill all of them, since they all have the exact same immune systems. On the other hand, it seems that a lack of men gave these women more time and energy to cultivate some of the most elaborate forms of ant agriculture ever studied.

According to Himler, ants often evolve highly unusual reproductive strategies. But all-female ant societies are highly rare.

via BBC News

This isn't to say that B and T cells will be forced to do our bidding. "The goal is to perturb the cell as little as possible," said Robert Cohen, one of the authors of the paper in Nano Letters. Each synthetic patch only covers a small part of the cell's surface, so the cell can still carry out its normal functions without disturbance.

In fact, "backpack" is a near-perfect analogy for this technology. The synthetic patch application consists of three layers of polyelectrolytes (certain types of polymers). Inside, the middle layer is whatever the scientists want the cell to be carrying: examples include a vaccine, a protein marker, or magnetic nanoparticles for controlled direction. The bottom layer of the patch is a polymer that attaches to the surface of the immune cell, and the top layer binds to other cells.

If you squint while you're watching this video (courtesy of MIT TechTV), the hordes of marauding B cells kind of look like ants with backpacks:

Now that we know human immune cells can carry a bit of extra load, it's time to start thinking about how we can use that capability to treat cancer or improve our bioimaging — or if you prefer, what kind of pencil boxes and notebooks will go into these new cellular backpacks.

Leaf-cutter ant image from Wikimedia Commons.
Surface-functionalized cell diagram courtesy American Chemical Society.

Tiny backpacks for cells [MIT News Office]
Surface functionalization of living cells with multilayer patches [Nano Letters]

In an article published with Win and Smolke's research in the October 17 issue of Science, Ehud Shapiro and Binyamin Gil describe the unique difficulties facing synthetic biologists:

The challenges of biomolecular computer engineering are best illustrated by comparing them to those of electronic computer engineering. In the latter, one can conceive of an advanced and innovative computer design, use one's favorite computer-aided design software, send the design to a chip fabrication facility, and with luck have a working electronic device in short order. In the field of biomolecular computers, one can equally dream of innovative designs that can be made, in principle, from known protein building blocks. However, protein engineering is in infancy compared to electronic circuit engineering. There is no protein design software to turn to, and no fabrication facility that can engineer a protein to a specification of its function. Therefore, researchers cannot construct their own advanced protein machinery and must make do with DNA, RNA, or naturally available proteins.

Win and Smolke made do with RNA, and the results are spectacular.

Their experiment began with the determination of three main components: a sensor, an actuator, and a transmitter, each a different type of short RNA molecule. Using these three components, Win and Smolke created RNA devices that take in a molecular input and translate that to an output of a certain gene expression. In effect, these RNA devices act as internal gates within the cell. By combining these internal gates in different ways, Win and Smolke constructed logical operations within the cell that programmed for the production of certain proteins.

The result is a logical system that can take in two different inputs — theophylline and tetracycline — and produce a corresponding output — in this case, the Nobel-Prize-winning green fluorescent protein (GFP). Programmed to mimic an AND gate, the cell produces GFP only when both theophylline and tetracycline are present. Conversely, programmed as an NOR gate, the cell produces GFP only when both theophylline and tetracycline are not present. Programmed as an NAND gate, the cell produces GFP in every case but the one where theophylline and tetracycline are both present. Basic Boolean algebra meets bioengineering, and now we can order our cells around just like we do our computers.

Win and Smolke's system is the first that can take in multiple inputs, which is an amazing advantage for would-be biological programmers. It's also very flexible and easy to program; scientists can treat it as a "plug-and-play" framework, in which it's easy to keep changing the components of the RNA device to allow for an infinite number of computations. And the best news is that though Win and Smolke published only the results they got from testing in yeast cells, they say that their devices will translate to mammal cells with no trouble. Your cells could soon be detecting tumors or conducting their own targeted gene therapy to fight cancer — and this at a molecular level, all under the direction of scientific and medical professionals. Sounds good to me.

Caltech Engineers Build First-Ever Multi-Input "Plug-and-Play" Synthetic RNA Device [Caltech]
Higher-Order Cellular Information Processing with Synthetic RNA Devices [Science]
RNA Computing in a Living Cell [Science]

Images from Science.

The major goal for García and his colleagues was to recreate the way natural bone gradually blends into tendons and soft tissue. García and his then-graduate student Jennifer Phillips describe the necessity of their work in a press release from Georgia Tech:

"One of the biggest challenges in regenerative medicine is to have a graded continuous interface, because anatomically that's how the majority of tissues appear and there are studies that strongly suggest that the graded interface provides better integration and load transfer," said Andres Garcia, professor in the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology. ...

"Every organ in our body is made up of complex, heterogeneous structures, so the ability to engineer tissues that more closely mimic these natural architectures is a critical challenge for the next wave of tissue engineering," said [García's then-graduate student Jennifer] Phillips, who is now working at Emory University as a postdoctoral research fellow in developmental biology.

Using gene therapy, the Georgia Tech researchers were able to artificially engineer that elusive bone-soft tissue interface. They started with a 10-mm scaffold of collagen (pictured above); collagen is the primary protein in the connective tissue of mammals. They then coated this collagen scaffold with a gene delivery vehicle that would encode for a protein called Runx2. At one end of the scaffold, they planned for a high concentration of Runx2 — one that would slowly decrease until it reached the other end. They now had a collagen scaffold with a gradually varying coat of Runx2.

After that, they seeded the scaffold with dermal fibroblasts, causing skin cells to sprout uniformly on the Runx2-coated collagen. Skin cells on the area with a high concentration of Runx2 turned into bone, and skin cells at the other end became soft tissue. Voilà — a natural-seeming gradient of bone to tendon was the final result. And they didn't just stop there: García's group went on to implant their collagen scaffold in vivo for several weeks, and successfully.

This technology isn't just useful for building artificial limbs; it could also provide major advances in surgery. The Georgia Tech press release had this to say to anybody with aching knees:

Oftentimes, ACL [anterior cruciate ligament] surgery fails at the point where the ligament meets the bone. But if an artificial bone/ligament construct with these types of graded transitions were implanted, it might lead to more successful outcomes for patients.

As someone whose ACL still frequently complains about a seven-year-old injury, this correspondent salutes García, Phillips, and the rest of the Georgia Tech team.

Engineers create bone that blends into tendons [EurekAlert!]
Engineering graded tissue interfaces [Proceedings of the National Academy of Sciences]

Nature's full of clawed animals, but the frogs' defense mechanism is unique in the natural world because their claws literally rip through the skin when extended. They're also made of bone instead of keratin (sorry, no adamantium claws are known to exist in reality, except for this guy). Researchers aren't sure if the claws are retractable or not, and as Yong notes, they may never really want to find out:

The clawed frogs belong to a family called Arthroleptidae that were discovered in Central Africa more than a century ago. At first, people wondered if the claws just stuck through the skin as a side effect of the preservation process. Alternatively, the frogs may have used them to grip or climb. Their true function as defensive weapons only became clear when naturalists first described actually picking up and handling live animals.

Doing so is a mistake, and anyone who makes it is punished with a series of deep, bleeding wounds inflicted by the struggling animal as it kicks out violently with its claws. The ability is well known to the people of Cameroon, who only ever hunt the frogs with machetes or spears.

In the X-Men movie, Wolverine, when asked if it hurts to pops his claws, answers, "Every time." One can't help but think that the same is true for the frogs.
...
However, many amphibians have extraordinary healing abilities that can even regenerate severed limbs. It may be that the clawed frogs, like their comic-book counterpart, have a 'healing factor' that closes up the wounds that open every time their claws are used.

Source: Not Exactly Rocket Science