Imagine tiny robots marching along your arteries, fighting off infections and repairing damaged genes, extending your life by tens, perhaps even hundreds of years. That's the potential of nanotechnology. Neat, eh? As long as those extra years are covered by our pensions.
It sounds like the stuff of science fiction but already in labs around the world, tiny machines, smaller than the diameter of a human hair, are being crafted with the idea being that they can work on our bodies from the insides, carrying out running repairs.
Along with repairing our bodies, nanotech could even enhance our bodies -- replacing bits and pieces with something that either looks, or works, better -- think long, slender legs and blood that can carry more oxygen to our muscles than the stuff we're born with.
Nanotechnology -- the manipulation of matter at the scale of atoms and molecules -- is already working its way into our lives. It's in our TVs in the form of organic light emitting diodes (OLEDS). It's in sunscreen -- nanoparticles of zinc oxide and titanium dioxide block out the harmful UV despite being so small they're invisible to the naked eye. And antimicrobial socks that keep feet smelling sweet carry nano particles of silver that have antibacterial effects.
But nanotech also has a great deal of potential to ease us into old age. For starters, it will enable us to delete a gene that makes us more likely to develop a disease. Professor Gang Bao, an expert in nanotechnology at Georgia Institute of Technology in Atlanta, is developing nanotech that can carry out repairs to damaged genes -- he's doing it by hijacking one of the body's repair systems.
The idea is to take a sample of stem cells from the patient's bone marrow and inject it with the nanotech -- proteins that can hone in on damaged DNA, and snip it out. This super-protein also contains the blueprint for the genetic sequence that should have been there in the first place, allowing the DNA to make itself a non-mutated section. The corrected stem cells can then be added back to the bone marrow, and the disease -- such as sickle cell anaemia -- is cured. Prof Bao thinks clinical trials could start as soon as three or four years.
The same type of gene-modifying nanotech could slow ageing itself. "We have the ability to precisely modify the genome," says Bao. "If we know a specific gene responsible for ageing, we could modify it to slow down the process." No such gene has been identified, however -- yet.
He's already thinking about the ethics of the situation. "I'm not sure we want to have a world full of old people," he says. But if the nanotech could also cut out cancer-causing genes, or those related to dementia, being old might not equate to being frail. He reckons that if the tech comes to fruition, we could be living to well over 100 and have healthy lives the whole way.
Tweaking our genes isn't the only way nanotech could tackle the Big C. At the University of Manchester in the UK, nano experts are investigating proteins that carry iron nanoparticles with them. The proteins stick to receptor molecules on the surface of cancers, called cell- death receptors. A magnet can then be used to make the nanoparticles clump together causing the receptors to spring into action and the cancerous cells self-destruct.
The research at the moment is concentrating on getting the nanotech assassins to reach the target cancers successfully, rather than careening about the body aimlessly before being urinated out. One possibility is to make these cancer missiles heat seeking. The part of the body containing the cancer would be warmed up so the nanotech could hunt down its target.
Dr Robert Freitas at the Institute of Molecular Manufacturing in Pilot Hill, California, is known for thinking big when it comes to small stuff. He published his first scientific paper describing ideas for medical nanorobots back in 1996, calling these robots respirocytes -- artificial red blood cells that could carry hundreds of times more oxygen than our standard-issue ones. An on-board computer would control oxygen release and even resuscitate someone who was drowning.
Freitas also proposed the vasculocyte, which he says would mend damaged arteries as it marched along them on telescopic legs. On top of the vasculocyte would be thousands of rotors, spinning and swapping damaged molecules for healthy ones. "My current view is that we'll have some medical nanorobots by the 2030s", says Freitas.
Nanotech is already being used to help build 'bioscaffolds' on which replacement organs can be grown -- synthetic windpipes have been grown in this way. But it'll not be too long before we're able to do the same with more complex structures, such as lungs and hearts -- perhaps even making them bigger and more capable than the ones we're born with.
All of this begs an intriguing question. Just how long might we be able to live if all of this research pans out? Freitas has developed models with extraordinary predictions that far outplay Bao's 100 years or so. His calculations, which assume that nanorobots can eliminate all frailty, disease and age-related deaths, suggest that as long as we avoid getting hit by a bus, we could live for not hundreds but thousands of years. Perhaps as long as 39,000 years. Would you want that?
Adapted from the article The Nano Elixir of Life written by Katharine Sanderson in the first issue of the new science magazine, Science Uncovered, out on November 21st. Visit www.science-uncovered.com to download a free sample issue.