Technology

Nano-medicine's fantastic voyage

Nano-drugs are already here. Next up? Tiny robots that can repair your DNA.

Picture your body as an ancient house, one that remains in good condition for hundreds of years because every time something goes wrong, tiny contractors repair the damage. That’s the promise of nano-medicine, according to Fantastic Voyage: Live Long Enough To Live Forever, a 2004 book by noted American inventor and futurist Ray Kurzweil and medical scientist Terry Grossman. Now, these technologies, which seemed fantastical only six years ago, are becoming a reality in medical labs all over the world. In the not-too-distant future, scientists predict nanobots could help us live longer, and virtually wipe out diseases like cancer.

Kurzweil and Grossman’s title is a tribute to Fantastic Voyage, a 1966 sci-fi classic about scientists who go on the ultimate mini-sub mission to remove a blood clot inside a diplomat’s head. The double Oscar winning film helped inspire the development of nanotechnology (and not just because it starred Raquel Welch, who sported tight-fitting scuba garb while fighting off blood cells). Nanotechnology, which involves the creation and use of materials and devices at the atomic and molecular level, first started with a scientific challenge to “think small” issued by physicist Richard Feynman in a 1959 lecture called “There’s Plenty of Room at the Bottom.” Feynman talked about developing the ability to manipulate and control things on an increasingly micro scale.

“People tell me about miniaturization, and how far it has progressed today,” Feynman said. “And there is a device on the market, they tell me, by which you can write the Lord’s Prayer on the head of a pin. But that’s nothing, that’s the most primitive, halting step in the direction I intend to discuss.” Forget the Lord’s Prayer, he added. “Why cannot we write the entire Encyclopaedia Britannica on the head of a pin?”

Nano-medicine is simply an application of nanotechnology focused on repairing the body and detecting and curing disease. Feynman got the ball rolling by noting it “would be interesting in surgery if you could swallow the surgeon.” According to Kurzweil and Grossman, that may soon be possible, thanks to cell-sized medical nanobots, reminiscent of the Proteus sub that carried Welch around in Fantastic Voyage.

Primitive versions of such nanobots are already in development. Professor Moshe Shoham of the Technion-Israel Institute of Technology, for example, has a prototype one millimeter in diameter that could one day be used to remove blood clots. It uses little arms to hold its position in the blood stream, and can be powered by an electromagnetic field outside a patient’s body. And Shoham’s robot is massive compared to the two-legged molecular machine being developed by Andrew Turberfield, a physics professor with the Clarendon Laboratory at Oxford. It may one day walk unaided in a controlled fashion along strands of DNA, and is being designed to haul cargo around cellular nano-factories.

If nanobot technology is perfected, Ahmed Busnaina, director of Northeastern University’s Center for High-rate Nanomanufacturing in Boston, says a whole new world of medical opportunities and ethical questions will open up. “Imagine what changes when you can repair human DNA,” he says “People age because DNA gets mutated and defective. So if you can fix that, you reverse or halt aging. You can then have people playing tennis at 130. Women can wait until 65 to have babies. People going back to college at 70 to start a second career.”

Nobody, of course, expects the Grim Reaper to start looking for a new gig tomorrow. But thanks to nanotechnology, medical revolutions — like licking cancer — could one day be possible. Mauro Ferrari, chairman of the Department of Nanomedicine and Biomedical Engineering at the University of Texas Medical School in Houston, insists nanotech is not just the future of medicine. “It is the now,” he says, noting the market for nano-drugs in the U.S. alone has already surpassed US$5-billion. (One estimate for the global market in 2015 is US$220 billion.)

“Look at the world’s top 300 people on the Forbes rich list last year,” he says, “and you’ll find one billionaire from pharma. That’s Patrick Soon-Shiong. And he is a nano guy. It’s time for skeptics to realize that what’s going to happen down the road will be truly transformational.”

Soon-Shiong represents the first big nano-medicine success story. He has a net worth of more than US$5 billion thanks to American Pharmaceutical Partners, which he founded and then sold after a decade-long battle to get to FDA approval for Abraxane, a re-engineered form of Taxol, a chemotherapy treatment. Taxol is effective but highly toxic, thanks to a delivery solvent that causes severe side effects. Soon-Shiong’s idea for Abraxane was simple: dump the solvent and deliver the same treatment attached to nano-particles of protein, which limits the side effects. To get the drug to market, Soon-Shiong faced a huge uphill battle. APP investors thought he was hyping Abraxane’s prospects. Fraud accusations were even tossed around. But the concept was vindicated after Abraxane landed FDA approval for breast cancer patients.

The next generation of nano-drugs do not need to wait for big advances in nanobot development — much of the technology is already here. Material scientists and cancer researchers from the U.S. Department of Energy’s Argonne National Laboratory and the University of Chicago have already developed a way to kill cancer cells by connecting gold-plated iron-nickel microdiscs to cancer-seeking antibodies. The technique — featured on the February cover of Nature Materials — is currently ready for animal testing.

“The use of nano-materials for cancer treatment is not a new concept,” Argonne nano-scientist Elena Rozhkova told the journal. “But the ability to kill the cells without harming surrounding healthy cells has incredible potential. Such a topic can only be approached with the expertise of markedly differing disciplines such as physics, chemistry, biology and nanotechnology, and can make a great impact in important areas of science and modern advanced technologies.”

In Germany, Busnaina says MagForce Nanotechnologies is already testing a similar technique on humans, and early indications show a threefold increase in survival rates. “The idea,” he says, “is to attach a very small particle to antibodies, which travel through the veins. So you can have antibodies very specific to brain cancer that carry iron oxide particles, which are magnetic and about 20 nanometers in size. They get injected in the blood, or better yet, in the vicinity of the tumour. And they attach themselves only to the target cancer cells.” The patient then gets an MRI and “the magnetic field will vibrate and heat the particles, which kills the cancer cells and only the cancer cells.”

The process takes about 10 minutes, but it is repeated for about an hour. “After that,” Busnaina says, “the person goes home. No drugs or radiation are involved, and the body dispenses the particles via the kidneys in about 48 hours.”

Thanks to nano-medicine, a diagnostics revolution is also underway, which is just as important because, as Busnaina points out, all cancers can be treated if they are caught early enough. His lab is developing a biosensor that is smaller than a grain of sand and 250 times better than current technology. “The next stage,” he adds, “is a biosensor under the skin of high-risk people that serves as a cancer alarm. Or installed in someone in remission, where it will trigger immediate treatment if cancer comes back.”

Shana Kelley, a biochemist and professor with the University of Toronto’s Leslie Dan Faculty of Pharmacy, says nano-diagnostics is all about size matching. “What we are trying to do is use nano-materials to make the next generation of testing devices.” Instead of using a relatively large piece of gold to try to detect low levels of very small molecules, doctors will be able to “use something nano scale and achieve much better sensitivity, which allows you to do a lot more things clinically.” And that could quickly take the profession from a handful of cancer screens to one for every single kind of cancer.

“A typical user of the health-care system,” Kelly says, “probably doesn’t really realize just how much guesswork goes on. I think any doctor would agree that the job would be much easier with more specific therapeutics and diagnostic tools that catch more diseases and catches them early.” That’s what nanotechnology offers, so “when today’s kids are adults, it is possible that nobody dies from cancer.”