Harvard researchers create method to measure nano exposure for safety, delivery

With the use of nanotechnology on the rise in drug delivery, researchers are making efforts to measure the amount of nanomaterials present in human tissue. Because of the way these materials interact with living cells, and because they pose a possible risk, being able to measure these levels is a difficult and important challenge.

Now engineers at Harvard School of Public Health have developed a method to measure the density of such nanomaterials as they come into contact with cells and tissue. Beyond the safety aspect of being able to determine a patient's level of exposure to nanoparticles, the method could also be used to help develop new drug delivery systems that make use of the tiny materials, according to a report in the Harvard Gazette.

The problem on the safety side is that, although the FDA is working on a way to regulate nanotechnology, it is difficult to determine the way a material might act at the nano scale as opposed to in larger quantities. They often act very differently because of a meteoric rise in surface area that comes in contact with living tissue and their ability to penetrate cells.

"The biggest challenge we have in assessing possible health effects associated with nano exposures is deciding when something is hazardous and when it is not, based on the dose level," senior author Philip Demokritou told the Gazette. "At low levels, the risks are probably minuscule. The question is: At what dose level does nano exposure become problematic? The same question applies to nano-based drugs when we test their efficiency using cellular systems. How much of the administered nanodrug will come in contact with cells and tissue? This will determine the effective dose needed for a given cellular response."

The team published its study this week in the journal Nature Communications, describing what they call a volumetric centrifugation method, which they tout as fast, simple and inexpensive.

- here's the Gazette story
- get the research abstract

Editor's Corner: Nanotech promises new frontier as FDA decides how to regulate