Chemical Technology November 2015

NANOTECHNOLOGY

that their thread was strong, but nevertheless significantly weaker than a spider’s.” Spiber are partnering with North Face to produce The Moon Parka, a product that is to go on tour later this year and which you may be permitted to buy in 2017. I do like the idea of spider-silk clothing. But imagine the same material used to repair injuries? It should be as bio- compatible as silk. “It’s hard to see unless you look closely, but this is the beginning of biological nanotechnology. These are some of the very first deliberately designed biological molecules to make it into a non-pharmaceutical market. Technologically, the silks in these fabrics are made of designed components an order of magnitude smaller than Intel’s best transistors. And (under biological conditions) are significantly more functionally versatile,” says toufka , also on Hacker News. Yes, and that’s the grey goo problem. Since the machines are actual living organisms, they might be able to reproduce outside of the factory. Spider silk fabric is nice. Spider silk clogging up our waterways, or being excreted as waste by some infectious illness; not so nice. And yes, we’re definitely on the cusp of something incred- ible which will change our experience of healthcare, as well as the world in which we live. As the nanomachines we want to build, or the scale of action we wish to take, shrinks and becomes more complex, we are definitely going to find it easier to work with genetically engineered organisms who will build things for us. We’re looking at nanomaterials which need to be deliv- ered as a payload to a specific activation site in the body, without triggering an immune response or getting lost. We

making copies of itself…the first replicator assembles a copy in one thousand seconds, the two replicators then build two more in the next thousand seconds, the four build another four, and the eight build another eight. At the end of ten hours, there are not thirty-six new replicators, but over 68 billion. In less than a day, they would weigh a ton; in less than two days, they would outweigh the Earth; in another four hours, they would exceed the mass of the Sun and all the planets combined— if the bottle of chemicals hadn’t run dry long before.” This doomsday “grey goo” would – wait for it – wait for it – threaten life on earth. On the other hand, Spiber, a Japanese company, has just developed the first artificial spider silk fibre which they’re called Qmonos. The fibre is produced during a fermenta- tion process led by genetically engineered yeast producing recombinant proteins. They spent 11 years on this, using 656 gene synthesis designs. It turns out, however, that you can’t just make the pro- teins and expect proper silk to result. As dre85 notes on Hacker News, “… expressing the proteins is the easy part. Spinning the proteins into a thread was the tough part. Ap- parently spiders have special excretion structures/organs that can anneal the proteins to the right conformation ex- tremely quickly as they are ejected. This is why a spider can basically just jump off of anything and shoot out his ‘bungee cord’ while falling which is incredibly fast if you think about it. When the researchers tried to replicate this by simply shooting the concentrated protein solution through a tiny capillary they weren’t able to achieve the same molecular structure for their thread nor at the same speed. They noted

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Chemical Technology • November 2015