SciTech #ScienceSunday Digest – 13/2015.
Permalink here: http://www.scitechdigest.net/2015/03/nanoparticles-stimulating-neurons.html
Nanoparticles stimulating neurons, Nanotubes stimulating neurons, Bioprocessing aptamer hydrogels, Controlling circadian rhythms, Making CRISPR better, DNA nanofabrication, Festo’s insect robots, Magnetic heat & sound, Nanolasers & photonic guides, Plasma shielding.
1. Stimulating Neurons with Gold Nanoparticles.
A promising new technique for precisely stimulating neurons has been developed that involves coupling gold nanoparticles to other molecules that specifically bind to neuronal sodium channels without blocking them http://news.uchicago.edu/article/2015/03/12/new-technique-uses-light-take-genetics-out-optogenetics. When irradiated with light of a specific wavelength the gold nanoparticles heat up and this causes the channels to open up and initiate a signalling cascade; antibodies were also used to bind the particles to different neuronal channels. The particles also remained bound to the cell surface and the neurons didn’t suffer reduced signalling efficacy after prolonged and repeated artificial activation. Referred to as optogenetics without the genetics, future applications might include artificial vision restoration. A very flexible platform with different nanoparticles perhaps responding to different wavelengths of light and so potentially allowing simultaneous addressable signals; I wonder if they can signal output in a similar fashion too? Other nanoparticles sensitive to radio waves have also been shown to open up the blood brain barrier http://www.nouvelles.umontreal.ca/udem-news/news/20150325-nanorobotic-agents-open-the-blood-brain-barrier-offering-hope-for-new-brain-treatments.html.
2. Carbon Nanotube Fibers Interface with the Brain.
In related neuronal stimulation news, carbon nanotube fibers have been developed that allow for intimate two-way brain stimulation and measurement and have proven superior to metal electrodes http://news.rice.edu/2015/03/25/carbon-nanotube-fibers-make-superior-links-to-brain-2/. The fibers measure one quarter the width of a human hair, terminate at a functional tip about the width of a neuron, and are made by wet-spinning millions of carbon nanotubes together. The strength and conductivity of the fibers are certainly attractive, but what convinced the group to pursue this avenue was their flexibility, softness, and biocompatibility. The plan is to develop the platform into deep-brain-stimulation applications at first before exploring other possibilities.
3. Bioprocessing with Hydrogels and DNA Aptamers.
A new microfluidic system comprises flexible fins capped with DNA aptamers that are embedded in a hydrogel able to respond to different stimuli https://www.seas.harvard.edu/news/2015/03/catching-and-releasing-tiny-molecules. When a biological solution is run through the chip, the aptamers bind to the target molecule they were designed for, and when the stimulus is applied the hydrogel moves the aptamers into a different environment to release the molecules; thus specific molecules can be quickly sorted and separated from a complex solution. The proof-of-concept involved pulling the thrombin enzyme from a mixture of proteins. The hydrogel can be made sensitive to temperature, light, electric/magnetic fields, ionic gradients, etc while the aptamers can be specifically targeted and respond to pH, temperature, and salt. Seems like a nice, modular, and extensible technology with lots of applications.
4. Controlling Circadian Rhythms and Improving Sleep Cycles.
A couple of interesting studies this week provided insights into the control of circadian rhythms in the brain and improving sleep, a summary of both can be found here http://www.kurzweilai.net/neuroscientists-identify-key-cell-type-in-the-brain-that-controls-body-clock. First, a key group of neurons were identified in the suprachiasmatic nucleus that produce a signalling neuropeptide called neuromedin S, which is both necessary and sufficient for the control of circadian rhythms in the animal; this provides an interesting target to hack. Second, the latest evidence for artificial light, particularly blue light, having a negative impact on our sleep and health has been demonstrated and makes a strong case for limiting the exposure of such light before sleep.
5. Increasing CRISPR Efficiency Eightfold.
A new development of the CRISPR genetic engineering system results in the system being eight times more efficient at inducing genetic modifications in cells https://www.mdc-berlin.de/44343169/en/news/2015/20150325-mdc_researchers_greatly_increase_precision. The advance was made possible by introducing genetic elements that inhibit one of two methods of DNA strand repair, which are (i) homology-directed repair in which introduced genetic elements contain flanking DNA used as a template to splice the cut, and (ii) non-homologous end-joining in which free DNA ends are joined without a template and tiny deletions occur. Basically, the new system inhibits (ii) from occurring and so making it far more likely that (i) will work to incorporate your genetic change of interest. In tests up to 60% of all cells were modified in one go with the new system, something that holds promise for effective and widespread somatic cell engineering at some point.
6. DNA Origami & DNA Modular 3D Building Units.
DNA origami and DNA as a programmable molecular building material took another important step forward this week with a new approach to joining and modular 3D DNA building units by snapping together complementary shapes http://www.tum.de/en/about-tum/news/press-releases/short/article/32303/. This group has been a powerhouse in pushing DNA origami technology over the years. The new work programs DNA to self-assemble into 3D building blocks that are precisely shaped to fit together by incorporating the short-range binding mechanism known as nucleobase stacking that can snap multiple blocks together; currently the platform allows three different binding mechanisms to be used. The team used this platform to build micrometer sized filaments and nanoscale machines with moving parts, including nanoscale actuators able to switch or cycle between states orders of magnitude more often and more stably than any prior DNA origami technology.
7. Festo Robotics Continue to Impress.
Festo is an incredible innovative company that continually produces amazing robots that have previously included a kangaroo, seagull, dragonfly, air jellies, and others. This week it showed off its latest insectoid additions, cooperative ant robots with 3D printed bodies and electronics are able to operate autonomously or work together to achieve goals, and truly elegant butterfly robots that really have to be seen to be appreciated http://spectrum.ieee.org/automaton/robotics/industrial-robots/festo-bionic-ants-and-butterflies – be sure to check the videos. In related robotics news a new Amazon contest hopes to spur faster and more efficient robotics automation in warehouses http://www.technologyreview.com/news/536086/amazon-robot-contest-may-accelerate-warehouse-automation/.
8. Controlling Heat and Sound with Magnets.
Vibrations through 3D materials, known as acoustic phonons that propagate both heat and sound, have been shown for the first time to possess magnetic properties that allow them to be manipulated with magnetism http://spectrum.ieee.org/nanoclast/semiconductors/materials/for-first-time-reseachers-demonstrate-heat-and-sound-are-magnetic. In one proof-of-concept the team demonstrated they could reduce the amount of heat flowing through a semiconductor by 12%. Using the technique heat and sound waves can be steered magnetically, which is an interesting result and a new phenomenon to manipulate. But the experimental setup was precise and it isn’t obvious how immediate applications might be developed.
9. Nanolasers and Photonic Guides.
One of the most efficient, easy to build, and compatible nanolasers ever build has been fabricated out of a monolayer sheet of tungsten diselenide atop a standard optical cavity base that is hoped to enable the device to more easily integrate and speed-up modern electronics http://www.kurzweilai.net/a-nanolaser-and-a-bendable-light-material-promise-to-speed-up-microelectronic-devices. Also, mentioned in the same article in related news is the fabrication of a 3D printed spatially-variant photonic crystal able to bend light around tight 90 degree corners without the losses that would occur in conventional fibers and other materials; yet another enabling photonic feature able to benefit improvements in modern electronics.
10. Dynamically Generated Plasma to Dampen Shockwaves.
Boeing has developed (or at least filed a patent on) a technology able to dynamically generate plasmas able to mitigate or prevent damage from shockwaves caused by nearby explosive blasts for example http://spectrum.ieee.org/tech-talk/aerospace/military/boeing-files-patent-for-electromagnetic-arc-generator-to-protect-against-explosive-shockwaves. The system detects an explosion nearby and calculates when and where-from the shockwave will arrive, then uses an electromagnetic arc generator (and a LOT of energy) to heat a specific region of air in the path of the shockwave into a plasma able to attenuate or absorb the shockwave. Patents don’t get granted without demonstrating enablement and I do wonder if we’ll get to see this system successfully demonstrated.
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