With the cumulative U.S. federal investment in the National Nanotechnology Initiative since 2001 now topping $16.5 billion, is the technology truly coming of age?
At the nanoscale—one nanometer is a billionth of a meter—specially engineered materials, additives and devices promise medical and economic advances, in part because of unexpected quantum effects seen at the super-small scale. During a 21 November event at AAAS, experts expressed continuing optimism for the field, yet most also raised questions about possible health and environmental risks, and how best to regulate nanotechnology.
Researchers already have developed nanoparticles to deliver cancer-fighting drugs directly to tumors, said Omid Farokhzad, director of the Laboratory of Nanomedicine and Biomaterials at Brigham and Women’s Hospital, an associate professor of anesthesia with the Harvard Medical School. The particles, described in the Proceedings of the National Academy of Sciences, suggest a way to avoid the dose-limiting toxicities associated with cisplatin, a chemotherapeutic agent used to treat 50% of all cancers. “The drug goes everywhere,” Farokhzad explained. “It has an enormous affect on non-cancerous cells.”
In contrast, the new nanoparticles, developed in collaboration with scientists at the Massachusetts Institute of Technology, leverage unique binding properties to attack tumors more specifically. Earlier this year, the technology helped launch clinical trials of BIND-014, a targeted nanoparticle being investigated as a way to combat several different types of cancer. Preliminary data with human patients have surpassed expectations, Farokhzad reported. The drug (in this case, a commonly used chemotherapeutic agent called docetaxel) is released in a targeted, controlled fashion, making it possible to achieve a tumor concentration 20 times higher than the conventional delivery system in preclinical studies, he said. “If you tried to reach the same tumor concentrations of the drug with a traditional approach,” he added, “it would be a lethal dose for the patient.”
Three other speakers described efforts to apply nanotechnology to an array of products, from better concrete and antimicrobials to airplane wings. Recent breakthroughs described on the National Nanotechnology Initiative’s Web site have included an ultrasensitive, highly flexible electronic sensor that might improve artificial skin and a strategy for loading millions of gold particles or “nanorods” into a cancer cell, which could suggest a way to “cook” tumors.
The AAAS event, part of a series of discussions on “Science and Society: Global Challenges,” was co-sponsored by AAAS, the American Chemical Society and the Georgetown University Program on Science in the Public Interest. David Kestenbaum of National Public Radio served as moderator.
Researchers have successfully tested water filtration systems based on tiny “rust magnets” called nano-magnetites that remove arsenic from drinking water, said Pedro J. J. Alvarez, the George R. Brown Professor and Chair of Civil and Environmental Engineering at Rice University. Further, in Mexico, filtration systems are being developed based on carpets impregnated with photocatalytic “buckyballs,” or buckminsterfullerenes, an extremely stable, ball-shaped carbon molecule (C60), he noted. “They can clean wastewater on their way to irrigate crops,” he said. “In five years or so, you’ll see more of these success stories.”
Alvarez noted also that nanotechnology is being investigated to strengthen concrete and prevent it from cracking. Strong, lightweight airplane materials incorporating nanotechnology might be designed to resist lightning strikes and perhaps to de-ice wings, too, said J. Alexander Liddle, group leader for nanofabrication research at the Center for Nanoscale Science & Technology, U.S. National Institute of Standards and Technology. On the medical front, nanotechnology-enhanced microbials in devices such as catheters could dramatically reduce infections in hospitals, said Kristen M. Kulinowski, research staff member at the Institute for Defense Analyses (IDA) Science and Technology Policy Institute.
The cost of nanomaterials remains a concern for some applications, speakers said. Nanotechnology for water filtration might be feasible for treating water in remote villages, for example, but not for larger communities, said Alvarez. But Farokhzad said he believes nanotechnologies could in fact reduce the typical drug-development investment, which can reach $1.3 billion.
Alvarez expressed concerns about scientists’ understanding of the potential risks associated with nanotechnology. Researchers have so far published roughly 200,000 papers on the promise of nanotechnology, he noted. By comparison, an estimated 5500 papers have so far looked at nanotech-related environmental, health and safety issues, Kulinowski said.
She added that the occupational health and safety of workers should be a primary focus of future research into the health impacts of nanotechnology. Farokhzad suggested that regulation of different nanotechnologies could be handled on a “case-by-case basis.” Kulinowski agreed that this approach might work for the U.S. Food and Drug Administration. She added, though, that the U.S. Environmental Protection Agency “would have a hard time with the case-by-case approach under the Toxic Substances and Control Act because that encompasses a huge variety of substances.”
The 2012 U.S. federal budget request would provide $2.1 billion for the Nanotechnology Initiative, an increase of 11.3% above the current FY 2011 level of $1.9 billion. Environmental, health and safety issues are a primary focus of research across multiple agencies.