Issue Date: November 24, 2014
Google’s Nanoparticle Diagnostic Vision
When the Internet impresarios at Google speak, the world listens. So the usual hoopla ensued last month when Google announced its latest ambition: to develop nanoparticle diagnostics paired with a wearable detector. One interview even brought up the tricorder, the fictional diagnostic device from “Star Trek.”
Diagnostic development doesn’t happen at warp speed. Experts say Google hasn’t revealed enough information to know what if anything sets it apart from myriad competitors. Even if Google’s ideas survive the years-long development gauntlet, they add, the technology faces societal hurdles to adoption.
“Imagine you want to explore Parisian culture, and you do it by flying a helicopter over Paris once a year,” said Andrew Conrad, head of life sciences at the company’s semicovert Google X laboratories, while announcing the project at the Wall Street Journal’s WSJD Live conference on Oct. 28. “That’s what doctors do now” with annual screening, he said.
Google X envisions a way to mingle with Parisians, as it were: functionalized nanoparticles designed to bind to something specific, such as circulating tumor cells. Ideally, the nanoparticles would be swallowed in pill form and enter the bloodstream. The particles’ tiny cores could be made from magnetic iron oxide, a compound already in Food & Drug Administration-approved nanoparticle contrast agents. A wearable device that creates a magnetic field could summon the particles from outside the body, Conrad said. “We’d call them back to one place and we’d ask them, ‘Hey, what’d you see? Did you find cancer?’ ”
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The life sciences arm of Google X is on a mission to move health care from reactive to proactive. Novartis has already licensed the lab’s “smart contact lens” technology for continuously measuring glucose in tears, an alternative to daily blood draws for diabetics. Also in the works is the Baseline Study, which has the goal of biochemically defining a “healthy” human being. Google X’s moon shots go far beyond life sciences—the lab is also working on self-driving cars and high-altitude balloons that deliver Internet access to remote areas.
The secrecy at Google X is the stuff of legend, and the nanoparticle platform is no exception. “I have to admit I have never heard of this project, and this is exactly my field of research,” says Wolfgang Parak at Philipps University in Marburg, Germany. “Until we know what Google really has done and what they want to do, it is not possible to judge this project,” Parak says. “It could be yesterday’s news—or something exciting.”
Cloak-and-dagger routine aside, Google has assembled a crack team of scientists for the purpose of tackling diagnostics, and that’s a good thing, says Efstathios Karathanasis, who is used to a much more serendipitous approach to diagnostic development at Case Western Reserve University. That said, he thinks Google’s hypothetical pill would run into hurdles as soon as it’s swallowed. “The nanoparticles and their coating must survive the hostile environment of the stomach and the gastrointestinal tract,” he says.
Google X is aware of the metabolic obstacles, if its partnership with Massachusetts start-up Entrega is any indication. Entrega is working with Google X to explore oral delivery routes for nanoparticles. The start-up’s platform is based on work from chemical engineer Samir Mitragotri at the University of California, Santa Barbara. Entrega has developed tiny circular patches with a drug payload that gets packaged inside a capsule. Once the pill is swallowed, Entrega’s patches act on the small intestine the way a nicotine patch would on the skin, gradually releasing the drug over the course of hours.
Entrega’s patches are proprietary, but Mitragotri’s lab has reported prototypes made from a compressed polymeric matrix of carbopol, pectin, and sodium carboxymethylcellulose. An ethyl cellulose backing layer keeps digestive enzymes from prematurely breaking down both patch and cargo (J. Controlled Release 2013, DOI: 10.1016/j.jconrel.2013.09.004).
A nanoparticle-summoning wearable device doesn’t exist, but Google is thinking about detection modalities. Steven Conolly visited the Googleplex last year to talk to the X team about his research in magnetic particle imaging. The technique maps the spatial distribution of magnetic iron oxide nanoparticles in living rats or mice (Adv. Mater. 2012, DOI: 10.1002/adma.201200221). Unlike magnetic resonance imaging, “we only see the tracer—there’s no background from human tissue,” explains Conolly, a bioengineering professor at UC Berkeley.
Magnetic particle imaging is currently performed with rodent-sized scanners. The technique is not yet approved for human use, though the consumer electronics company Philips is developing a human magnetic particle imaging scanner at its Hamburg, Germany, research site. Even if the technology were applicable to humans with cancer, Conolly cautions that no one has figured out how to target nanoparticles to cancer cells specifically and reliably.
Also unclear is how diagnostic information will affect treatment decisions. And privacy advocates may find cause for concern in a medical diagnostic from an information company. Google X has no plans for its diagnostic technology to interface with other Google products, says Vikram S. Bajaj, a chemist by training who is the scientific lead on the nanoparticle platform and the Baseline project. Bajaj’s team has verified that their nanoparticles bind to desired targets in vitro and is sending prototypes into artificial limbs.
A Google diagnostic is, at a minimum, years away and has no guarantee of catching on, says Northwestern University’s Chad A. Mirkin, a founder of three nano-focused biotech firms. Mirkin’s is a cautionary tale. Nanosphere Inc. commercialized a diagnostic strategy reported in a 2000 paper from his lab. Starting from blood, saliva, or urine samples, Nanosphere’s gold nanoparticle probes can rapidly detect and identify bloodstream infections. Although the product is available to hundreds of hospitals, buy-in has been slow in coming, he says.
“It’s phenomenal that Google is investing in blue-sky things that go beyond their current core expertise,” Mirkin says. “But nano is an area that’s both prospered and suffered from enormous hype. It’s important not to trivialize the challenges ahead.”
Google X Life Sciences head Andrew Conrad announces the lab's nanoparticle project at the Wall Street Journal Live conference on October 28.
Credit: Wall Street Journal
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