Nanotech applications using nanoparticles to deliver drugs in the body may have to add another dimension to their design considerations—different chemical surfaces covering a nanoparticle can attract different types of blood proteins to coat the nanoparticle, which might affect how the nanoparticle moves through the body and where it ends up. KurzweilAI.net points to this post by Bob Grant on The Scientist news blog (free registration required) “A new twist on nanoparticle behavior“:
Researchers hoping to develop nanoparticles as medicines or carriers of therapeutic molecules have much more to worry about than the type of material they plan on miniaturizing, according to a study in this week’s issue of the Proceedings of the National Academy of Science [abstract].
Researchers in Ireland found that the corona, or cloud of proteins and other biomolecules that adheres to a nanoparticle immersed in biological media (in this study human blood plasma), changes depending on the size of the nanoparticle and the charge on its surface. That, in turn, can affect the particles’ therapeutic action in the body.
Nanotechnology is “an enormously powerful tool, but we need to know how to control it,” Kenneth Dawson, a University College Dublin physical chemist and the study’s senior author, told The Scientist. “We have to look at what’s happening at the surface of these materials rather than just the materials themselves. It’s a new science really.”
…This, Dawson said, could have major implications for nanoparticles used as human therapeutics. For example, a particle of one size and surface charge might be trafficked to the brain of a patient, while another particle of a different size and charge, even though it’s made of the same material, might be shuttled to the liver. “[A nanoparticle] can go places you didn’t want it to go, and when it gets there it might pick up different signals that can be confusing,” he said.
…University of Rochester professor of environmental medicine and toxicology Gunter Oberdorster, who was not involved in the study, noted that drug makers may be able to make use of the differing physiological effects different coronas have on a nanoparticle’s fate in the body. “Nanomedicine may take advantage of this and target a specific organ.” While he called Dawson’s study “an important step,” he cautioned that in vivo studies must confirm the effects of nanoparticle size and surface character in living organisms.
—Jim
