The Speculist

Getting the Technology together.

Blogger Al Fin has posted twice in the last couple of days on the subject of organic nanotech - the technology that will make the "onboard doctor" possible.

On Thursday Al wrote about "promiscuous enzymes" - enzymes that aren't so choosey about what chemical reactions they get intimate with.

Ever since scientists learned they could design new genes--and thus new proteins--in the lab, they have been hoping to gain enough specificity in the design of enzymes to allow the use of artificial enzymes to create new and useful molecules that have never existed in nature. Clearly, that is nano-assembly in an enzymatic form, with potential approaching anything Eric Drexler may have dreamed for his own nanoassemblers.

...

“The enzyme synthase was there ready to be evolved, and with our methodology, we were able to rapidly and efficiently evolve it down a pathway of our choice,” Keasling said. [Keasling is a scientist with Berkeley Lab, a US DOE national laboratory] “We are recapitulating evolution into intelligent design. In the case of this particular Grand fir enzyme synthase, it naturally makes a soup of small amounts of 52 different products. We were able to focus it instead on making large amounts of one of seven of those products.”

While the researchers have not yet reached the point where they can design a promiscuous enzyme to make any kind of product they want... this demonstration represents a significant step in that direction. The idea would be to one day be able to design an enzyme synthase that would evolve along a specific functional pathway to yield a desired molecular product, then introduce it into microbes for mass production.

And this, ultimately, could happen within the body without intervention.

Assuming you could manufacture a drug within the body, there is the issue of how it should be delivered where it's needed. Nature has provided the solution. Al Fin:

Nanotechnologists too often approach the assembly of their nano-machines on a de novo basis, ignoring the legions of nano-machines that evolved over a billion years ago. Nano-engineers had better begin learning from the biologically evolved nanodynamic structures, or they will be made irrelevant by bio-nano engineers.

Agreed. Life isn't just "the ultimate existence proof" for self-assembling nanotech. Life is nanotech.

An Oxford University physicist sees the future of nanotechnology in the workings of one of Nature's tiniest motors, that which allows some bacteria to swim by rotating slender filaments known as flagella.

'The bacterial flagellar motor is an example of finished bio-nanotechnology, and understanding how it works and assembles is one of the first steps towards making man-made machines on the same tiny scale,' said Dr Richard Berry, a Tutorial Fellow in Physics at Oxford University. 'The smallest man-made rotary motors so far are thousands of times bigger.'

This motor has the same power-to-weight ratio as an internal combustion engine, spins at up to 100,000 rpm and achieves near-perfect efficiency. Yet at only 50 nanometres across, one hundred million would fit onto a full-stop. The only other natural rotary electric motor is in the enzyme ATP-synthase.

Artificial microbes carrying a cargo of medicine could be powered by this engine.