Permalink here: http://www.scitechdigest.net/2015/07/gene-therapy-hearing-single-molecule.html
Gene therapy hearing, Single molecule transistor, Better metamaterials, Crystal light traps, Optofluidic neural probe, Synthetic foods, New particle phenomena, New CRISPR tools, Memory tracking, Regenerating neuronal axons.
1. Restoring Hearing with Gene Therapy
Deaf mice have had their hearing restored via a gene therapy that used a standard engineered adeno-associated virus to deliver a correct version of a single gene to sensory hair cells in the cochlea http://vector.childrenshospital.org/2015/07/gene-therapy-restores-hearing-in-deaf-mice/. The mechanistic insights into sound perception are equally nice to consider: the gene encodes a channel protein that sits on the microvilli of sensory hair cells whose deformation due to pressure waves causes the channels to open and allow calcium ions to enter the cell. There are a number of different genes that can cause deafness and this platform might be tailored to correct all of them as needed depending on the genetics of each patient.
2. Single Molecule Transistor
A basic experimental transistor has been demonstrated that consists of a single phthalocyanine molecule surrounded by a hexagon of 12 indium atoms http://phys.org/news/2015-07-transistor-molecule-atoms.html. At this scale structures are hypersensitive to single electron hops and in this case fabricated with a scanning tunnelling microscope; it turns out that electron flow across the molecule is coupled to the orientation of the surface-bound molecule and is capable of generating large conductance gaps.
3. Improvements in Metamaterial Designs
A few interesting new metamaterial designs this week. First, a new and incredibly thin carpet cloak has been designed to incorporate periodic teflon and ceramic dielectric structures that can effectively bend light to shield anything beneath the cloak to give the appearance of a flat surface http://spectrum.ieee.org/tech-talk/semiconductors/materials/a-slender-bright-invisbility-cloak. This is a two-dimensional metamaterial design and now they just need to make the thing to prove that it works. Second, a new metamaterial design is able to accurately preserve the phase of light while guiding it around sharp corners and abrupt bumps http://phys.org/news/2015-07-clever-cloaks-unique-metamaterials-phase.html. Third, progress towards lossless perfect lenses http://www.mtu.edu/news/stories/2015/july/bringing-back-magic-metamaterials.html.
4. Trapping Light in Crystal Granules
Tiny crystals of hexagonal boron nitride can effectively trap light within their structures http://phys.org/news/2015-07-orbits-intriguing-material.html. Incident light becomes trapped within the material in a form known as a phonon polariton, and at certain resonant frequencies the light adopts simple closed orbits and this produces hot spots of electric fields that form elaborate geometric patterns. The resonant frequencies depend on the physical shape of the crystal and this is an instance of storing light inside a tiny piece of material for extended periods. A nice, elegant new phenomena that we’ll have to wait to see applications for.
5. Tiny Optofluidic Neural Probe
A tiny flexible neural probe has been developed, a tenth the diameter of a human hair, wirelessly controllable, and able to both deliver drugs to deep inside the brain and also turn on LED lights to switch on optogenetically activated neurons http://neurosciencenews.com/optogenetics-device-neurons-2253/. This new device causes far less damage and displacement compared to existing devices. In experiments it was able to effectively deliver multiple different drugs including gene delivery vectors to the brains of mice and was also able to influence and control behaviour via light activation. Seems to be a great new platform tool for pushing this space forward.
6. Better “Synthetic” Foods
At some point we’re going to have to drop that “synthetic” label for these new food technologies. First this week was presentations about the ongoing development of 3D printing with foods and the economic and personalised sensation benefits that might accrue http://www.ift.org/newsroom/news-releases/2015/july/13/3d-printers-poised-to-have-major-implications-for-food-manufacturing.aspx. Second, the cost of cultured lab-grown burger meat continues to build on the advance announced in 2013 and is currently projected to decline from $300,000 down to $65 per kilogram http://phys.org/news/2015-07-scientist-texture-lab-produced-hamburger.html.
7. Experimental Confirmation of Weyl Point Phenomena
In a nice reduction of theory to practice massless particles with a single point in their energy spectrum , called Weyl points, have been proven to exist experimentally with the aid of new photonic crystal designs http://newsoffice.mit.edu/2015/Weyl-points-detected-0716. This work was done with microwave light in order to simplify the crystal fabrication but there is no reason visible light couldn’t be used in future. Possible future applications include optical devices, high-power single-mode lasers, and bulk materials or lenses that only allow a certain angle and a certain frequency of light to pass through.
8. CRISPR with Non-Homologous Insertions and Light Activation
A new CRISPR system can achieve targeted insertion of genetic sequences up to 5,000 base pairs long into mammalian cells via non-homologous end-joining, i.e. without the need to include lengthy homologous sequence arms on each side of the genetic sequence / gene of interest and DNA cut or insertion site http://nextbigfuture.com/2015/07/over-5000-base-pairs-were-inserted-into.html. Other benefits include simpler, cheaper plasmid vectors and while the efficiency of integration was not high there is scope to improve this if needed in future. Another newly engineered form of CRISPR now allows light-activation of the CRISPR machinery for applications such as regulating genes with light for example http://www.the-scientist.com/?articles.view/articleNo/43255/title/Optogenetics-Meets-CRISPR/.
9. Measuring Memory, Improving Memory, and Altering Neuronal Firing
Electrodes implanted into rat brains and measuring activity from place cells in the hippocampus suggest that there are definite gaps in certain types of normal memory, far from the smooth flow that typically characterises memory http://www.hopkinsmedicine.org/news/media/releases/scientists_watch_rats_string_memories_together. A new type of transcranial direct current stimulation known as transcranial pulsed current stimulation appears to boost neuronal excitability and muscle skill acquisition while transcranial magnetic stimulation appears to show good results in dampening neuronal excitability and associated tinnitus symptoms http://www.kurzweilai.net/could-this-new-electrical-brain-zap-method-help-you-learn-muscle-skills-faster.
10. Regenerating Neuronal Axons in Severed Spines
I missed this a couple of weeks ago but switching off or deleting one particular gene was sufficient to induce neuronal regeneration and axon growth in the spines of mice with severed spines http://neurosciencenews.com/corticospinal-axon-regeneration-paralysis-2189/. The neurons were able to bridge the site of injury regardless of whether gene inactivation happened immediately, four months post injury, or one year post injury and are able to form tentative synaptic connections. As a candidate treatment the gene inactivation might be targeted to certain neurons or the specific region of interest.