Nanoparticle safety has become a major worry in recent years. In 2007, there was evidence discovered that some nanoparticles could damage DNA and lead to cancer. This led to a call for studies on the safety of different types of nanoparticles.
Yesterday, an article we found online at Science Daily's website (here's a link: http://dld.bz/acJmM) discussed some work along these lines by researchers at NIST. They figured out a way to capture nanoparticles, where they could be exposed to cells to see whether they are pose a hazard, then released.