Nanobots Communicate Through Bacteria

[Sabre]

New Scientist article

Injecting bacteria into the bloodstream might sound like a health risk, but those propelled by a whirling helical tail, or flagellum, could one day be used to send messages between cancer-fighting nanobots.

Maria Gregori and Ignacio Llatser at the Polytechnic University of Catalonia in Barcelona, Spain, envision a future in which nanobots in the body sense tumour cells and release anticancer drugs to fight them. But one machine can't defeat a tumour single-handedly; it needs some way of telling the others to swarm on the target.

Radio signals won't travel through a liquid, and chemical forms of communication using pheromones or calcium ions work only across large or microscopic distances. On the scale of a few millimetres – the distance from one blood vessel to another – there is no way to transmit information reliably.

So the pair came up with the idea of using bacteria with flagella, in this case a non-pathogenic strain of E. coli, to send the information. The idea is to encode a message in a DNA sequence that is inserted into each bacterium's cytoplasm. Each nanobot would contain bacteria inscribed with every message that could be needed

When a nanobot encounters a tumour, it would release the correctly encoded bacteria. These would then swim towards other nanobots, attracted by the nutrients stored there. Once there, the encoded DNA sequence binds with chemical receptors and its message – telling it where to swarm or to release its drugs – is acted upon.

Six minute transfer

In a computer simulation, the pair found bacteria that had flagella took about 6 minutes to traverse a distance of 1 millimetre from a transmitting to a receiving nanobot. They used an encoding scheme that enabled them to encode up to 300,000 DNA base pairs – or 600 kilobits of information.

"That's a bandwidth of 1.7 kilobits per second. It's not high, but for the biomedical applications we envisage it should be [fast] enough," Llatser says.

Others need convincing, however. "These are just simulation results. Everything is possible in simulation," says Andrew Adamatzky of the unconventional computing department at the University of the West of England in Bristol, UK.

Like the Barcelona team, Adamatzky also uses biology to model networks. He studies how slime moulds can be used in route planning and has famously remapped the UK's and Mexico's road networks with the organism Physarum polycephalum.

"While their simulation results seem OK, only experimental evidence will convince me that their technique is working," says Adamatzky.

Now this is just scary to think about what could go wrong (or changed easily) with this...

[complacent]

absolutely fascinating. thanks.

[drwrx]

Now this is just scary to think about what could go wrong (or changed easily) with this...

The question is what, theoretically, could be carried on the bacteria? Creating a specific DNA sequence is time consuming and expensive and would likely only work on the specific target (i.e. lymphoma cells of a particular individual). I see the implications, but there are cheaper and easier ways to attack people. And I suspect these would be very detectable from a sample in a lab. So it would NOT go completely undetected.