SciTech #ScienceSunday Digest, 19/14.Rejuventing aged tissues, retinal motion wiring, 6-base DNA, neuroprosthetics, smarter nanoparticles, human glycome, evolved metamaterials, humanised pig organs.1. Rejuvenating Aged Brains and Muscles.
Big news this week was the rejuvenation of brains and muscles in aged mice by use of blood factors from young mice http://hsci.harvard.edu/news/functioning-aged-brains-and-muscles-mice-made-younger
. These appear to be follow-up experiments to what I’ve reported on a year or two ago, but in this case were repeated in duplicate via (i) parabiotic surgery joining the circulatory systems of an old and a young animal, and (ii) straight injections of the protein GDF11, thought to be the main factor active in the parabiotic results, straight into older mice. Both approaches resulted in the rejuvenation of older mice; their hearts appear younger and stronger, circulation and blood flow improves, exercise capability improves, cognitive decline is reversed, and aged olfaction reverts to similar capabilities to that of young mice. Pretty exciting stuff but still needs to be replicated in humans. Subsequent scenarios might include transfusions from young to old, protein injections, drugs to boost aged production, gene therapy interventions, and synthetic biology applications. Turns out that another factor, klotho, was also found to protect against cognitive decline with aging by forming stronger synapses https://www.fightaging.org/archives/2014/05/klotho-influences-cognition-as-well-as-aging.php
. 2. Sensing Motion via Retinal Wiring.
Brain mapping efforts in conjunction with citizen-science game EyeWire
applied to high-resolution scans of slices of mouses retina have resulted in maps of retinal neurons and their wiring that provide insight into how motion is detected so quickly http://www.nature.com/news/wiring-of-retina-reveals-how-eyes-sense-motion-1.15147
. Because individual photoreceptors are indifferent to the movement of an object, it turns out that bipolar cells play a key role, with some links to the next layer of cells able to signal immediately while others signal with a slight delay, with the exact wiring and signal timing able to communicate when one photoreceptor cell fires shortly after another, i.e. when an object causes movement of light across the retina. Expect these insights to be co-opted in the near term by designers of neuromorphic imaging chips to produce better machine vision systems. 3. Genetic Codes with Six Instead of Four Base Pairs.
The engineering possibilities with genetic codes have been significantly expanded with the demonstration of an additional pair of bases that integrate well with DNA, taking the number of bases from four to six http://www.wired.com/2014/05/synthetic-dna-cells/
. The new base-pairs, dubbed X and Y for now, were incorporated into plasmid vectors and it was shown that bacterial cells could replicate the new additions to DNA, provided the X and Y molecules were added to the nutrient media for the cells to absorb. The group is trying to engineer the cell to be able to synthesise its own X and Y molecules without the need for their presence in the environment, and future work will demonstrate transcription into RNA and subsequent translation into protein. Using standard three-base codons means that the new system could encode 6*6*6 = 216 different amino acids, massively expanding the design space for both synthetic biology and DNA Origami applications. 4. Extended Capabilities Come to 3D Printing.
A couple of interesting new capabilities for 3D printers this week. First, a new 3D printing head and materials allow a 3D printer to simultaneously print both structural plastics and metallic conductors in the same print job http://www.computerworld.com/s/article/9247934/This_3D_printer_technology_can_print_a_game_controller_electronics_and_all
. The group demonstrated the new capability by printing a games controller with embedded conductive wires and simply connected an arduino board to the exposed ends of the conductors to encode button presses and control a computer game; be sure to watch the video - the more materials the more of that board could be printed. Second, plans for a new 3D printer that produces custom tinted / pigmented makeup (powders, pastes, creams) was launched and opens up a range of interesting possibilities https://plus.google.com/u/0/+MarkBruce/posts/i3mvQaG6VJ7
. 5. The Latest on Neuroprosthetics.
The on-going development of implantable neuroprosthetic chips that repair or enhance brain function and neural communications continues apace. Some chips have reached a level of sophistication that they are now being surgically implanted into human brains to restore function in those paralysed http://www.washingtonpost.com/business/economy/ohio-surgeons-hope-chip-in-mans-brain-lets-him-control-paralyzed-hand-with-thoughts/2014/04/29/c45515e2-ccaf-11e3-a75e-463587891b57_story.html
, measuring the correct brain signals and sending these to the correct muscles. Other chips under development seek to interface with the hippocampus, restoring or improving the ability to form new and recall old memories or repairing other cognitive functions and are currently being pushed by DARPA http://nextbigfuture.com/2014/05/darpa-researchinr-brain-implants-to.html
, building on work like this http://iopscience.iop.org/1741-2552/10/6/066013/
that demonstrated memory encoding via a similar device and hippocampus in primates. 6. Increasing Sophistication of Nanoparticles VS Cancer.
An engineered adeno-associated virus has two custom molecular locks that are only opened by two specific proteases that are present in high levels near cancer cells, which subsequently allows the virus to enter and deliver its payload to the cell of interest http://phys.org/news/2014-05-two-lock-cancer-therapy.html
; the idea is that (i) adding two, three, or more “locks” increases specificity and minimises off-target side effects, and (ii) the “locks” can be engineered as needed to target different cells. Another nanoparticle platform combines two drugs and a targeting molecule to reach cancer cells and deliver the different drugs hours apart from each other with particularly potent results http://phys.org/news/2014-05-nanoparticles-stagger-delivery-drugs-aggressive.html
. Both could be useful for facilitating therapies for stopping the growth of pancreatic cancers https://www.fightaging.org/archives/2014/05/halting-pancreatic-cancer-development.php
. 7. Changing Graphene’s Crystal Structure, Heat Conduction, and Photonics Properties.
This week’s advancements with the wonder material brought us news of (i) how an electric field can be used to accurately control the crystal structure of trilayer graphene to induce formation of metallic and semiconducting regions and allow construction of transistors http://uanews.org/story/playing-pool-with-carbon-atoms
, (ii) experimental confirmation of computer simulations demonstrating that graphene has more powerful heat conduction properties than previously thought http://www.mpip-mainz.mpg.de/news/thermal_conductivity
, and (iii) the creation of high-quality patterned graphene thin films for ultrafast optical communications http://www.swinburne.edu.au/media-centre/news/2014/05/graphene-photonics-breakthrough-promises-fast-speed-low-cost-communications.html
. 8. Progress on The Human Glycome.
The human glycome is the set of all the different types of sugar molecules that our body uses and produces, currently estimated at around 7,000 different sugars. Recent work suggests that the membranes of different cells are adorned with different sugars and this reflects a distinct and informative “sugar code” http://phys.org/news/2014-05-team-uncovered-sugar-ability-state.html
. The pattern and type of sugars adorning a cell wall appear to indicate tissue-type, phenotype or status, mobility, health, injury, and other markers - cancer cells have different sugars to normal cells for example. The work generated a glycome-microRNA map and future work should expand the sensing arrays to selectivity against more sugars to generate better sugar signatures and profiles of cell types - potentially improving our ability to quickly identify and target different cells. 9. Evolving Broadband Metamaterials.
Genetic algorithms are increasingly being used to evolve and design better metamaterial structures, with the latest work producing a metamaterial able to absorb infrared light over a wide range of wavelengths http://news.psu.edu/story/314511/2014/05/05/research/genetic-approach-helps-design-broadband-metamaterial
. Made of patterned layers of polymer and metal on a silicon base the material absorbs about 90% of infrared light and might find uses in shielding / obscuring infrared heat signatures or improving the efficiency of thermophotovoltaics to extract additional energy from sunlight. Better fabrication methods are needed for such materials to be adopted commercially however. 10. Scaling Up Production of Humanised Pig Organs.
Synthetic Genomics and United Therapeutics are teaming up to better develop humanised pig lungs and potentially supply the 400,000 human lungs that may be needed each year http://www.syntheticgenomics.com/media/press/050614.html
. The focus appears to be large-scale genomic engineering to produce pig cells capable of developing into embryos with humanised lungs that can later, when mature, be harvested and transplanted into patients that need them. Of course, the same techniques could be applied to other organs too. Earlier this year I covered other methods to grow human organs in pigs http://www.bbc.com/news/world-asia-25550419
, and cloning factories that could mass-produce them http://www.bbc.com/news/science-environment-25576718
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