Written by Catherine Bolgar
Nanomedicine takes advantage of its extremely small size—“nano” being one-millionth of a millimeter—to target drugs inside the body, fight cancer and other diseases, regenerate cells and provide contrast for medical imaging. As a result, nanomedicines hold out hope of curing hard-to-treat diseases. However, it also triggers fears, not least about whether they are safe for patients and the environment, and whether they are sufficiently regulated.
To date, about 40 nanomedicines have been approved by the U.S. Food and Drug Administration and about 20 by the European Medicines Agency, says Patrick Boisseau, nanomedicine program manager at the French Atomic Energy Commission and chairman of European Technology Platform on Nanomedicine. A further 130 nanomedicines are in clinical trials. It can take more than a decade for a drug, including nanomedicines, to receive regulatory approval.
However, despite this progress, much public discussion relating to nanomedicine is in fact based on their confusion with engineered nanomaterials, mostly inorganic materials produced by industry in large quantities.
“Most of the reactions expressed by citizens are directed at these [engineered] materials because products aren’t labeled and people don’t know whether appropriate toxicological studies have been performed as to whether the nanomaterials are safe for humans or the environment,” Mr. Boisseau says.
The only link between nanomaterials and nanomedicines,” he adds, “is the need to develop specific analytical techniques because the nanoscale is very, very small.”
Materials may behave differently at nanoscale, which is why nanotechnology is potentially so powerful, but also why ensuring safety, especially of nanomedicines, is so difficult, says Michael Schillmeier, professor of sociology, philosophy and anthropology at the University of Exeter in the U.K. and nanomedicine specialist.
“We can’t say nanomedicine is safe or not safe because nanoparticles can be very different, depending which nanoparticles are involved and how they interact with their environment,” he says. “Just by being nanoscale, they can be more toxic, more reactive, more resistant to erosion. There is no one nanoparticle.”
While materials may act differently on the nano scale compared with the macro scale, there can also be variations within a single substance. Nanomedicines’ impact can differ depending on their size, shape and texture. The trick is to understand whether such differences are positive or negative.
“We went to laboratories and toxicologists and found they often lack technologies or know how to sufficiently test and characterize nanoparticles,” says Prof. Schillmeier.
However, if clinicians discover specific properties of nanomedicines compared with macro forms of those drugs, they are required to inform regulators, Mr. Boisseau says.
“The body is a fantastic machine,” he adds. “Particles below five nanometers are filtered by the kidneys and quickly eliminated in urine, depending on whether the nanomaterial is organic or inorganic. Already, regulation for all medicines requires you to explain how your medicine is eliminated.”
The fact that the body doesn’t degrade inorganic particles can be useful in medicine. Metallic nanoparticles, for example, are injected into advanced cancerous tumors to enhance radiotherapy and destroy more cancer cells without increasing the radiation dose, he notes.
“If the patient is already 60 years old and, without treatment, could expect to live six months, and with it six years, then the regulator says the benefit is higher than the risk,” Mr. Boisseau says. “It would be different for treating young children because we do not know if children can live for 60 or 70 years with metallic nanoparticles in the body.”
Some medicines use nano properties to deliver drugs more efficiently to where they’re needed in the body. Often the drugs are strong, such as chemotherapy for cancer, but better-targeted delivery can make drugs work better while lessening side effects. Eventually, nanomedicine might make personalized medicine possible.
For now, research is focusing on drugs coated with nanotechnology that better target cancer and other diseases and distinguish between cancer cells and healthy cells, Prof. Schillmeier says.
Nanomedicine is not revolutionizing medicine, but may improve it.”
Meanwhile, pharmaceutical companies are looking at developing new nanomedicines or innovative nano-delivery systems for old drugs, Mr. Boisseau says. “Most people don’t care whether they have nanomedicine or not,” he notes. “They just care about therapeutic solutions that will treat them with the fewest side effects and best outcome.”
Catherine Bolgar is a former managing editor of The Wall Street Journal Europe. For more from Catherine Bolgar, contributors from the Economist Intelligence Unit along with industry experts, join the Future Realities discussion on LinkedIn.
Photos courtesy of iStock
