'Self-replicating' bogeyman strikes at nanotech researchers

'Nanotechnobabble' is already making life difficult for bio-nanotechnology researchers, with technophobes warning of the risk of uncontrollable, self-replicating nanobots overrunning the world, the Lorne Conference on Protein Structure and Function at Phillip Island, in Victoria, heard today.

Dr Cait McPhee, of Cambridge University in the UK, who is a research associate with the Interdisciplinary Research Centre for Nanotechnology, is investigating the properties of self-assembling protein fibrils. She told the conference that, under the right conditions, all peptide chains will spontaneously form amyloid fibrils -- the same type of molecular fibres that aggregate to form toxic amyloid plaques in the brains of Alzheimer's disease patients, and Lewy bodies in the dopamine secreting neurons of patients with Parkinson's disease.

McPhee said she had decided not to refer to the protein fibres her team is studying as 'amyloid fibrils' because of the connotations with brain diseases, and the risk that activists would exploit the research in their anti-nanotech scaremongering campaigns.

She said Prince Charles, well known for his opposition to genetically modified crops, had now begun warning of the potential hazards of nanotechnology and 'grey goo' -- an unfortunate term coined by nanotechnology pioneer Eric Drexler, who had warned of the threat of "obliteration of life that could result from the accidental and uncontrollable spread of self-replicating assemblies".

McPhee said another prominent nanotech critic had showed a woeful misunderstanding of physics, by warning that "the laws of physics break down at the nanoscale" -- the normal laws of physics, not quantum physics, apply.

McPhee said there was a huge gap between the science-fiction capabilities of nanobots and the current state of bio-nanotechnology research. Her own team was merely trying to fabricate single-crystal, semiconductor nanonwires to form nanoelectronic circuits.

Certain protein fibrils could be used to nucleate the growth of linear crystals of cadmium sulphide and zinc sulphide in supersaturated solution. The crystals are annealed at 350 Celsius to burn away the protein fibril, leaving behind a semi-conducting 'wire'.

Similar techniques are being used to develop ferromagnetic cobalt-platinum and iron-platinum systems to create two-dimensional magnetic materials.

McPhee said some protein nanofibrils are extremely strong and elastic, with superior properties to synthetic polymer fibres or steel fibres of the same diameter and size. Insulin microfibrils, for example, can tolerate pressures up to 2 gigapascals without rupturing.

She told the conference her research team is investigating the properties of nanofibrils, which have a range of interesting biological functions in living organisms. E. coli bacteria have an entire biosynthetic pathway devoted to the formation of secreted nanofibrils called curli, which allow them to attach to the surface of the gut.

Filamentous aquatic fungi secrete fibrils into the aqueous environment at the interface between the water-air interface, that allow them to punch through the surface tension and produce aerial hyphae to disperse their spores.

The eggs of some fish species that survive in muddy sediments when waterbodies dry up in summer are covered in hydrophilic microfibrils that regulate the movement of water into and out of the eggs.