SciTech #ScienceSunday Digest – 06/2016.

Permalink here: http://www.scitechdigest.net/2016/02/better-gene-delivery-better-dna.html 

Better gene delivery, Better DNA aptamers, Light effect transistor, Rejuvenation advances, Atomically precise materials, Integrated photonics modem, Electronic nematicity, Deep learning chips, Graphene lenses & electrodes, Flexiramic materials. 

1. Delivering Genes Across the Blood Brain Barrier

Using high-throughput screening techniques combined with methods of directed evolution, researchers screened millions of viral variants to create a novel, modified adeno-associated virus that is able to efficiently get past the blood-brain-barrier and deliver genes and genetic engineering tools to neurons and other cells of the brain http://www.caltech.edu/news/delivering-genes-across-blood-brain-barrier-49679. This obviates the need to drill a hole through the skull to inject these vectors and provides a far more elegant tool that can be used for CRISPR-powered modifications. In related news rats have been cured of a genetic liver disorder with a more effective CRISPR-delivery system involving a different adeno-associated virus carrying guide RNA and repaired-gene-insert and lipid nanoparticles carrying Cas9 mRNA instructions http://news.mit.edu/2016/crispr-curing-disease-repairing-faulty-genes-0201; 6% of liver cell transformations are sufficient for disease curing, which is 15 times more effective than other methods, but the group hope to boost this % in future. 

2. Better DNA Aptamer Technology

DNA aptamers can be artificially engineered to target and bind any molecular target in the body – proteins, viruses, bacteria, cells, tumours – but are limited by poorer binding-efficiency and instability due to enzymatic digestion. These two limiting factors have now been addressed http://www.a-star.edu.sg/Media/News/Press-Releases/articleType/ArticleView/articleId/4496.aspx with (i) the inclusion of an artificial base into the DNA that boosted binding ability by 100 times compared to existing aptamers, and (ii) the inclusion of a DNA-mini-hairpin structure that serves to restrict enzymatic digestion and boost lifetime in the body from hours to days. DNA aptamers like these could in theory be used instead of antibodies for therapeutic and diagnostic applications but are cheaper, quicker, and simpler to produce and obviate potential inflammatory side effects. 

3. Developing a Light-Effect-Transistor

Prototype light effect transistors have been developed with the aim of replacing standard field effect transistors in future chip designs https://www.technologyreview.com/s/600702/the-nanodevice-aiming-to-replace-the-field-effect-transistor/. A light effect transistor comprises a wire that conducts electricity when exposed to light and insulates when it is dark; a light-controlled switch in which light functions like a gate and with benefits including no reliance on dopant atoms and the ability to achieve smaller size dimensions to continue Moore’s Law. The demonstrations include semiconducting nanowires whose conduction changes by six orders of magnitude when switched, and can also function as an optical amplifier that performs logic operations when two or more laser beams are used. But the biggest unsolved question is how a chip would accurately address more than a billion nanowires with light? 

4. Rejuvenation via Senescent Cell & Amyloid Clearance 

First, venture-backed company Unity Biotechnology joins competition with Oisin Biotechnology aiming to develop and launch therapeutics that clear senescent cells from adult animals https://www.fightaging.org/archives/2016/02/25-median-life-extension-in-mice-via-senescent-cell-clearance-unity-biotechnology-founded-to-develop-therapies.php. Their latest work extends the median lifespan of mice by 25% and should help to attract additional funding and support for this approach; investors will want to get this into humans as soon as possible. And back in the lab another group finds a 35% lifespan extension by clearing senescent cells http://newsnetwork.mayoclinic.org/discussion/mayo-clinic-researchers-extend-lifespan-by-as-much-as-35-percent-in-mice-2/. Second, a partnership between companies Pentraxin and GSK is slowly bearing fruit with clinically-tested drug therapies that very effectively clear amyloid (misfolded protein clumps that accumulate) deposits from tissues and body fluids, intended for Alzheimer’s and other diseases but providing a platform for this area of rejuvenation therapies https://www.fightaging.org/archives/2016/02/what-next-for-transthyretin-amyloid-clearance-therapies.php. Boosting mitophagy also rejuvenates cells to a more youthful state http://www.eurekalert.org/pub_releases/2016-02/nu-mst020316.php. 

5. Atomically Precise Materials and Devices

Structural DNA technology can self-assemble nanoparticles into diamond-shaped crystal lattices https://www.bnl.gov/newsroom/news.php?a=11810. The DNA forms the rigid frame of the material, while complementary DNA binding ensures the nanoparticles bind in specific locations, leading to a diamond lattice about 100 times larger than conventional diamond; interesting platform for novel materials development. Bacteria produce self-assembled microcompartments to concentrate enzymatic production of certain molecules, and these compartments are being used as templates to engineer variants with novel functions and molecular production capabilities https://newscenter.lbl.gov/2016/02/04/toward-nanoscale-chemical-factories/, slowly building a platform of contained molecular production machinery that might one day be introduced inside human cells for exmample. 

6. NASAs Integrated Photonics Modem

NASA is building the first fully integrated photonics modem, simplifying optical on-chip systems design, and reducing the size of the large prototype down to conventional system-on-chip scales http://www.nasa.gov/feature/goddard/2016/nasa-engineers-tapped-to-build-first-integrated-photonics-modem. The chip uses lasers to encode and transmit data at 10 – 100 times faster than equipment available today. While testing of the device in space won’t begin until 2020 we might see commercial applications of this earlier, particularly in data centers and Internet backbone lines. 

7. Electronic Nematicity Key in Superconductivity

New studies indicate that the phenomenon of electronic nematicity, in which electron clouds in a material snap into an aligned and directional order, is a generic property common to high-temperature superconductors https://uwaterloo.ca/stories/waterloo-physicists-discover-new-properties. The electrons involved in superconductivity form patterns that exhibit different symmetries that preferentially align in one direction and which can compete with, co-exist, or enhance superconductivity. Hopefully this understanding allows for the future design of higher-temperature superconductors. 

8. Dedicated Deep Learning Chips on Smartphones

Eyeriss is a newly designed and developed dedicated deep learning chip for use in smartphones and other low-power applications http://spectrum.ieee.org/tech-talk/semiconductors/processors/a-deep-learning-ai-chip-for-your-phone. The chip is designed to allow these devices to run computationally demanding neural network algorithms quickly and efficiently on the device without offloading to the cloud, and using only one tenth of the energy of a typical mobile GPU. Agnostic to the type of neural network being run the chip can process image, sound, and other types of data as  needed and might also find deployment in autonomous platforms such as cars and drones. In related news Google’s DeepMind game-playing AI can now also navigate environments in first-person-shooters https://www.newscientist.com/article/2076552-google-deepmind-ai-navigates-a-doom-like-3d-maze-just-by-looking/ and I wonder if this can be transferred to robots to help in realworld environments, perhaps by using these dedicated chips. 

9. Graphene Lenses and Electrode Benefits

First, graphene has been formed into a clever fresnel lens by using a laser to pattern concentric rings of graphene oxide on its surface, and allowing optical focusing in the visible and infrared down to scales of 200nm http://www.swinburne.edu.au/news/latest-news/2016/01/focus-on-results.php. Second, graphene-coated electrodes turn out to be an excellent option for applications involving interfacing with neurons http://graphene-flagship.eu/graphene-based-interfaces-do-not-alter-target-nerve-cells. Finally, graphene cages formed around silicon anodes appear to enable higher capacity batteries that avoid the problem of cracking that such materials are usually limited by http://spectrum.ieee.org/nanoclast/semiconductors/materials/graphene-cages-cover-silicon-anodes-for-high-capacity-batteries. 

10. Flexiramics: Ceramics that Act Like Paper

A new material dubbed flexiramics is being developed and commercialised by a company called Eurekite http://arstechnica.com/science/2016/02/dutch-researchers-have-created-flexiramics-flexible-ceramics-for-circuit-boards/. Flexiramics appear to be a new class of materials that possess the mechanical properties of paper or thin textiles in being thin, foldable, and flexible while also exhibiting the properties of ceramics in being fireproof and nonconducting. The fabrics withstand 1,200 degrees Celsius for 24 hours without burning or melting. Printed PCBs will be the first application apparently but the possibilities are endless. 

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