Injectable Nanogel for Diabetics Monitors Blood Glucose Levels, Secretes Insulin as Needed
Injectable nanoparticles developed at MIT may someday eliminate the need for patients with Type 1 diabetes to constantly monitor their blood-sugar levels and inject themselves with insulin.
The nanoparticles were designed to sense glucose levels in the body and respond by secreting the appropriate amount of insulin, thereby replacing the function of pancreatic islet cells, which are destroyed in patients with Type 1 diabetes. Ultimately, this type of system could ensure that blood-sugar levels remain balanced and improve patients’ quality of life, according to the researchers.
Read more: http://www.laboratoryequipment.com/news/2013/05/injected-nanogel-can-help-fight-diabetes
(via laboratoryequipment)
Researchers Using Quantum “Squeezed Light” to Image The Insides of Cells
Conventional optical imaging is limited by the process of diffraction, the way light spreads out when it passes an object. The amount of diffraction depends, in part, on natural uncertainties in the position of the photons. Physicists think of this uncertainty as quantum noise.
In recent years, however, they’ve have worked out how to minimise the amount quantum noise by carefully manipulating the way photons are created. They call the resulting photons “squeezed light” and there has been no little excitement over their potential to beat the conventional diffraction limit in all kinds of applications.
One obvious use is in cellular imaging where squeezed light offers biologists a clear advantage for exploring cellular processes. Various groups have used squeezed light to make pioneering measurements inside cells. But the process of imaging to reveal spatial variations in the structure of a cell, has so far eluded them.
(via First Quantum-Enhanced Images of a Living Cell | MIT Technology Review)
Injectable Microbots, Steered by Magnets Deliver Drugs Exactly Where They’re Needed
Researchers from the Institute of Robotics in Zurich have recently developed an electromagnetically-controlled robot that can be delivered to the eye — by injection with a 23-gauge needle — and precisely positioned to sites where drug is needed.
…by coating the microbot with dye-containing nanospheres, the researchers have now repurposed the device to provide critical measurements of oxygen concentration in the eye to make quick diagnoses when vision unexpectedly fails. These new machines, and the apparatus which controls them, are part of a larger effort to deliver and control devices within several organ systems using remote power…
Steering is done by a device called the OctoMag control system (PDF). The OctoMag has three degrees of freedom (DOF) in positioning and two for pointing orientation. It is composed of eight DC-operated electromagnets arranged in a hemispherical configuration. It can create a maximum gradient of 1.5 Tesla per meter.
The microbots have a diameter less than 500um, and their length can be adjusted according to the size of drug reservoir needed. The researchers experimented with several materials for their microbot, but the best proved to be NdFeB (neodymium magnet). Most of the experiments thus far have been done in eyes from pigs or human cadavers.
(via Magnetically steerable, injectable microrobots could help treat blindness | ExtremeTech)
Michigan Researchers Working on Smart Dust Prototypes, Dubbed “Micro Motes”
The next generation of computers will be able to carry out complex calculations but will be little bigger than a snowflake.
Such tiny computers – nicknamed smart dust – would work much like their larger cousins, says Prabal Dutta at the University of Michigan in Ann Arbor. They will have tiny CPUs that run programs on a skeleton operating system and be able to access equally small banks of RAM and flash memory.
The plan is for such sensor-packed machines to be embedded in buildings and objects in their hundreds or even thousands, providing constant updates on the world around us.
Dutta’s group is creating the first prototypes, which they have dubbed Michigan Micro Motes. These devices, a cubic millimetre in size, come equipped with sensors to monitor temperature or movement, say, and can send data via radio waves.
…Like microscopic Robinson Crusoes, the motes will live off the power they can scavenge from their surroundings. A mote near a light source might use a tiny solar panel, while a mote running somewhere with greater temperature extremes can be built to tap into that, by converting the heat energy that flows between hot and cold into electricity.
So what will be smart dust’s killer app? The Michigan team says Micro Motes could be used to monitor every tiny movement of large structures like bridges or skyscrapers. And motes in a smart house could report back on lighting, temperature, carbon monoxide levels and occupancy. With motes embedded in all of your belongings it might be possible to run a Google search in the physical world. For example, asking Google “where are my keys?” would give you the right answer if they have been fitted with a mote.
(via Smart dust computers are no bigger than a snowflake - tech - 26 April 2013 - New Scientist)
Swiss Scientists Nanoengineer Artificial Antibodies Using Human Viruses
Swiss researchers have developed nanoparticles that can detect, and one day could combat, viruses.
When viruses enter the human body, the immune system responds to their presence. This triggers a sophisticated chain of events that leads to production of antibodies specific to the virus. Depending on the swiftness and effectiveness of the response, there are usually three possibilities: viruses are eliminated before they cause damage, they are eliminated after the person suffers a bout of sickness, or, in the worst case scenario, the virus spreads uncontrolled.
One option for combating viral infections is to develop “artificial” antibodies. These antibodies can have two uses: they can be used to detect infections and, if produced at large enough scale, they can be used to combat infections.
That’s what Patrick Shahgaldian and his colleagues at the University of Applied Sciences and Arts Northwestern Switzerland have been working on. Their solution is relatively simple. Find the virus that causes infection; imprint copies of it on a nanoparticle; then use this “mold” to trap the virus.
(via Nanoparticles formed using human viruses, to fight human viruses | Ars Technica)
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.
MIT and Harvard Engineers Use “DNA-Legos” To Construct Graphene Nanostructures
This news is a follow-up to an earlier post “Harvard Researchers Create Self-Assembling Nano Bricks Made of DNA.”
Engineers are now using self-assembling DNA nanobricks as a scaffold to build nanostructures out of graphene.
The MIT and Harvard researchers are essentially taking these shapes and binding them to a graphene surface with a molecule called aminopyrine.
Once bound, the DNA is coated with a layer of silver, and then a layer of gold to stabilize it. The gold-covered DNA is then used as a mask for plasma lithography, where oxygen plasma burns away the graphene that isn’t covered. Finally, the DNA mask is washed away with sodium cyanide, leaving a piece of graphene that is an almost-perfect copy of the DNA template.
So far, the researchers have used this process — dubbed metallized DNA nanolithography — to create X and Y junctions, rings, and ribbons out of graphene.
Nanoribbons, which are simply very narrow strips of graphene, are of particular interest because they have a bandgap — a feature that graphene doesn’t normally possess. A bandgap means that these nanoribbons have semiconductive properties, which means they might one day be used in computer chips.
Graphene rings are also of interest, because they can be fashioned into quantum interference transistors — a new and not-well-understood transistor that connects three terminals to a ring, with the transistor’s gate being controlled by the flow of electrons around the ring.
(via MIT and Harvard engineers create graphene electronics with DNA-based lithography | ExtremeTech)
Researchers Build Complex 3D Nano Structures Out of DNA By Manipulating How Strands Join
“We were amazed that it worked!” said Yan. “Once we saw that it actually worked, it was relatively easy to implement new designs. Now it seems easy in hindsight. If your mindset is limited by the conventional rules, it’s really hard to take the next step. Once you take that step, it becomes so obvious.”
The DNA Gridiron designs are programmed into a viral DNA, where a spaghetti-shaped single strand of DNA is spit out and folded together with the help of small ‘staple’ strands of DNA that help mold the final DNA structure. In a test tube, the mixture is heated, then rapidly cooled, and everything self-assembles and molds into the final shape once cooled.
Next, using sophisticated AFM and TEM imaging technology, they are able to examine the shapes and sizes of the final products and determine that they had formed correctly.
This approach has allowed them to build multilayered, 3-D structures and curved objects for new applications. “Most of our research team is now devoted toward finding new applications for this basic toolkit we are making,” said Yan. “There is still a long way to go and a lot of new ideas to explore. We just need to keep talking to biologists, physicists and engineers to understand and meet their needs.”
Carbon Nanotubes Used in Scaffolds to Grow Working Rat Hearts
Heart cells share many of the problems of neurons, from a research perspective; they are woefully inept at directing their own growth through space, requiring virtually every effort be made on their behalf, and even when led to the right place require all sorts of special genetic and chemical allowances. It was once thought impossible to regrow neurons, but lately we’ve come to realize that it’s just very, very finicky. Not the least of the reasons for this is conductivity; neurons cannot work unless they somehow come to meet one another such that an electrical signal can propagate between them. Heart cells are much the same — a cluster of so-called pacemaker cells keeps the whole thing contracting as one. This requires not just that the pacemaker signal pass between the cells, but that it happens fast enough for the heart to act seemingly as one coordinated unit.
In pursuit of this, the heart has a class of myocytes that form Purkinje Fibers, long cords that ferry pacemaker signals at a rate unsurpassed in the body. When a contraction signal leaves the pacemaking cells, its order reaches the furthest cells in the heart at an imperceptibly short time after it reaches the closest ones, and so the heart cells seem to beat as one. This ability is absolutely essential to a working heart, and has proven very difficult for organ transplant researchers to overcome.
Enter carbon nanotubes. As anyone familiar with the little critters will know, their important feature is a combination of strength, flexibility, and conductivity. Some combination of these virtues has made them of import to virtually every advanced research and manufacturing sector, from space elevators to flexible computers. Now, we must add conductive tissue development to that quickly growing list. By laying the conductive carbon nanotubes coated with a growth medium, researchers were able to create a scaffold that mimicked the utility of the Purkinje Fibers. By coating the scaffold in rat cardiomyocytes, they were able to create a colony of heart cells capable of contracting properly.
(via Carbon nanotubes make it possible to grow human hearts | ExtremeTech)
Researchers Embed Light-Emitting Probe into Single Living Cancer Cell, Successfully Track it for Eight Days
This nanoprobe could be an important breakthrough for photonic cancer therapy. The researchers suggest that it could be used to develop patient-specific cancer therapies, where an individual’s treatment could be tailored to their own genetic needs.
The probe can be used to detect specific proteins within the cell, and could be developed to sense DNA or RNA. When coated in molecules or antibodies that attract the desired protein, any of that protein within a cell will cling to the nanobeam like iron to a magnet, causing a shift in the wavelength of light it emits. This could be used in drug testing to see immediately if a drug is producing or inhibiting a certain protein.
“Devices like the photonic cavities we have built are quite possibly the most diverse and customizable ingredients in photonics,” senior author Jelena Vuckovic explained. “Applications span from fundamental physics to nanolasers and biosensors that could have profound impact on biological research.”
(via Scientists Insert A Light-Emitting Bioprobe Into A Living Cell | Popular Science)
