Nanoparticle Disguised as a Blood Cell Fights Bacterial Infections
The “nanosponges” work by targeting so-called pore-forming toxins, which kill cells by poking holes in them.
One of the most common classes of protein toxins in nature, pore-forming toxins are secreted by many types of bacteria, including Staphylococcus aureus, of which antibiotic-resistant strains, called MRSA, are endemic in hospitals worldwide and cause tens of thousands of deaths annually. They are also present in many types of animal venom.
There are a range of existing therapies designed to target the molecular structure of pore-forming toxins and disable their cell-killing functions. But they must be customized for different diseases and conditions, and there are over 80 families of these harmful proteins, each with a different structure.
Using the new nanosponge therapy, says Zhang, “we can neutralize every single one, regardless of their molecular structure.”
Zhang and his colleagues wrapped real red blood cell membranes around biocompatible polymeric nanoparticles. A single red blood cell supplies enough membrane material to produce over 3,000 nanosponges, each around 85 nanometers (a nanometer is a billionth of a meter) in diameter.
Since red blood cells are a primary target of pore-forming toxins, the nanosponges act as decoys once in the bloodstream, absorbing the damaging proteins and neutralizing their toxicity. And because they are so small, the nanosponges will vastly outnumber the real red blood cells in the system, says Zhang. This means they have a much higher chance of interacting with and absorbing toxins, and thus can divert the toxins away from their natural targets.
Harvard’s RoboBees to Fill Pollination Gap Caused by Bee Die-off
The Robobees won’t just share the pollinating function of real bees; the team is also looking to imbue them with colony behaviors. Although they won’t have a queen, the Robobees will live in a hive, which functions as a refueling station. Coordination algorithms and communication methods are in the works as well, hopefully giving the Robobees the ability to inform and help one another—sadly, without dancing.
The Microrobotics lab seems a host of possible uses for the robotic insects, including military surveillance, search and rescue missions, exploration of hazardous environments, traffic surveillance, and weather and climate mapping. Unfortunately, though, it seems they won’t be taking over all of the bees’ regular duties. While these Robobees don’t come with stingers yet, they aren’t off making honey, either.
Scientists Develop Robotic Bat Wing to Study Aerodynamics
For some time, engineers have puzzled over how bats could generate so much lift and so little drag, and how they could seem to do it while using less energy than even more specialized flyers like moths or birds.
Wind tunnel experiments offered insight, implicating the leathery skin that stretches between the wing’s four primary fingers. The soft wing material allows the bat to fold the wing and spill air even more effectively than a bird, on a given upstroke. This means that the lift generated in the downstroke, itself augmented by using the fingers to cup the air, won’t be cancelled out when the wing comes back up.
This week, a team of researchers decided to ditch the unreliable little creatures in favor of an automated solution… Brown University scientists built a mechanical wing to precisely mimic the structure and range of motion of the real thing, and to measure the effects of tiny changes in those motions. “We can’t ask a bat to flap at a frequency of eight hertz then raise it to nine hertz so we can see what difference that makes,” Bahlman said. “They don’t really cooperate that way.”
(via Robot bat wing reveals how mammals took flight and beat birds at their own game | ExtremeTech)
Researchers Mimic Cellular Structure of Plants to Nanoengineer Better Electrode
Essentially a network of tiny wires, it features a larger surface area than flat electrodes, giving it the leverage it needs to convert more electricity in a smaller form factor. This could lead to cheaper cell production and good things for the future of green energy. “This novel electrode coating technique has applications for fuel cells in the newest generation of hybrid cars, photovoltaic cells, rechargeable batteries or battery production for a wide range of green technologies,” said the university’s Dr. Adam Squires.
Nanowire Networks from Adam Squires on Vimeo.
(via Nature-inspired nano-material builds a better electrode, points to greener future (video))
![Bioengineered Nano-Jellyfish Captures Cancer Cells in the Bloodstream
[The device is] actually a microfluidic chip that’s been coated with long strands of DNA, which dangle down into the bloodstream and bind to any cancerous proteins floating past — directly imitating the way a jellyfish scoops up grub in the ocean.
If required, the chip can release these cells unharmed for later inspection. According to the chip’s designers at Boston’s Brigham and Women’s Hospital, the catch-and-release mechanism can be put to both diagnostic and therapeutic use in the fight against Big C, and can also be used to isolate good things, like fetal cells. The next step will be to test the device on humans…
(via Jellyfish-mimicking device could snatch cancer cells right out of the bloodstream - Engadget)](http://25.media.tumblr.com/tumblr_mdourvT4px1qgpcs1o1_r1_500.jpg)
Bioengineered Nano-Jellyfish Captures Cancer Cells in the Bloodstream
[The device is] actually a microfluidic chip that’s been coated with long strands of DNA, which dangle down into the bloodstream and bind to any cancerous proteins floating past — directly imitating the way a jellyfish scoops up grub in the ocean.
If required, the chip can release these cells unharmed for later inspection. According to the chip’s designers at Boston’s Brigham and Women’s Hospital, the catch-and-release mechanism can be put to both diagnostic and therapeutic use in the fight against Big C, and can also be used to isolate good things, like fetal cells. The next step will be to test the device on humans…
(via Jellyfish-mimicking device could snatch cancer cells right out of the bloodstream - Engadget)
Korean Roboticists Use Metamaterials to Muscle Tiny Robot That Jumps Like a Flea
To put a spring in their robot’s step, Minkyun Noh and colleagues at Seoul National University in South Korea turned to a shape memory alloy called nitinol. Such alloys have crystalline structures that allow them to flip between two stable positions when heated, or when an electric current passes through them.
The team built three springs out of nitinol that fold and lock in the same way as a flea’s leg does. By tethering their prototype to a power supply they were able get it to jump up to 60 centimetres - 30 times the robot’s own length.
Their next step is to work out how to give their prototype an on-board power supply and keep the leaping robot upright during flight and on landing. “Getting the power supply and electronics on-board is a challenge due to the light weight of the robot,” says Noh.
(via Flea-like robot takes giant leap in bot locomotion - tech - 31 October 2012 - New Scientist)
Synthetic Nanomachines That Act In Concert, Like Human Muscles
Nature manufactures innumerable machines classed as “molecular”. Highly complex assemblies of proteins, these machines are involved in the essential functions of living beings such as the transport of ions, the synthesis of ATP (the “energy molecule”), and cell division.
Our muscles are controlled by the coordinated movement of thousands of protein nano-machines, which function individually over distances of mere nanometers, but, when combined in their thousands amplify this telescopic movement until they reach human scale and do so in a perfectly coordinated manner.
Even though synthetic chemists have made dazzling progress over the last few years in the manufacture of artificial nano-machines, the coordination of several of these machines in space and time have until now remained an unresolved problem.
…for the first time, Giuseppone’s team has succeeded in synthesizing long polymer chains incorporating, via supramolecular bonds, thousands of nano-machines each capable of producing linear telescopic motion of around one nanometer.
Under the influence of pH, their simultaneous movements allow the whole polymer chain to contract or extend over about 10 micrometers, thereby amplifying the movement by a factor of 10,000, along the same principles as those used by muscular tissues.
[Passage heavily edited for clarity]
Biomimetic Robot Legs Not Only Look Like Human Legs, They Work Like Them Too
“Our robot, named Achilles, is the first to walk in a biologically accurate way. That means it doesn’t just move like a person, but also sends commands to the legs like the human nervous system does.
“Each leg has eight muscles—Kevlar straps attached to a motor on one end and to the plastic skeleton on the other. As the motor turns, it pulls the strap, mimicking the way our muscles contract.
“Some of Achilles’ muscles extend from the hip or thigh to the lower leg so they can project forces all the way down the limb. This allows us to put most of the motors in the hips and thighs. Placing them up high keeps the lower leg light, so that it can swing quickly like a human’s lower leg.
“In people, neurons in the spinal column send out rhythmic signals that control our legs. It’s like a metronome, and sensory feedback from the legs alters the pace. Your brain can step in to make corrections, but it doesn’t explicitly control every muscle, which is essentially why you can walk without thinking about it.
“For our robot, a computer program running off an external PC controls movement in a similar way. With each step, the computer sends a signal to flex one hip muscle and extend the other. The computer changes the timing of those signals based on feedback from the legs’ load and angle sensors. A similar control system handles the lower muscles.”
(via Rough Sketch: “We Made a Robot That Moves Like a Person” | Popular Science)
English Scientists Modelling Bee Brain to Build Autonomous Robot Bees
Scientists at the Universities of Sheffield and Sussex are embarking on an ambitious project to produce the first accurate computer models of a honeybee brain in a bid to advance our understanding of Artificial Intelligence (AI) and how animals think.
The team will build models of the systems in the brain that govern a honeybee’s vision and sense of smell. Using this information, the researchers aim to create the first flying robot able to sense and act as autonomously as a bee, rather than just carry out a pre-programmed set of instructions.
(via ‘Green Brain’ project to create autonomous flying robot with honeybee brain | KurzweilAI)
MIT Researchers Modify Skeletal Muscles to Respond to Light, Key Precursor for Muscle-Powered Robots
This is the first time tough, powerful skeletal muscle has been modified to react to light. Optogenetics researchers have done it with cardiac cells, which are already primed to beat on their own — now skeletal muscle, which normally requires some outside stimulus, can contract and expand at the command of light bursts.
Harry Asada, an engineering professor at MIT, said it’s more effective and less bulky than stimulating muscle with electrodes, especially for a robotics system where light weight and mobility are key.
Optogenetics entails introducing new genes into cells that make them react to a pulse of light, usually short bursts of laser light. Asada’s team worked with myoblasts, cultures of skeletal muscle cells, to express a light-activated protein. They combined several myoblasts into long muscle fibers and exposed them to 20-millisecond pulses of blue light.
In the video below, the blue dot represents the pulses, and you can see the fibers contract in response. A targeted burst of light makes one fiber contract, while a more diffuse beam can make the whole sheet move.
What’s more, the engineered muscle is pretty tough — to test its force, the team attached strips of muscle fiber to two tiny flexible posts inside a microwell. As the fibers contract, they pul the posts together, allowing the researchers to calculate its force. This could even be used as an artificial muscle gym, flexing the fibers to keep them in top shape.
The goal is to use strips of engineered muscle fibers to build flexible, realistic robots, which may swim inside the body’s blood vessels or run across a room. “With bio-inspired designs, biology is a metaphor, and robotics is the tool to make it happen,” Asada said. “With bio-integrated designs, biology provides the materials, not just the metaphor.
(via Light-Activated Muscle Could Make Robots Move Like Real Creatures | Popular Science)
