Rusting of the Trojan Horse – Metal Ion Mediation of Nanoparticle Toxicity

Thursday, October 14, 2010

Presenter

Robert Hurt

Robert Hurt, Ph.D.
Professor of Engineering
Director, Institute for Molecular & Nanoscale Innovation (IMNI)
Brown University

Abstract:
Understanding and managing nanomaterial risks requires knowledge of their underlying molecular interactions with natural substances in biological and environmental systems.   Many nanoparticles contain metals, and in suspension have associated free metal ions that can mediate biological responses.  In some cases, the ion is the primary actor at the biological target site, and the particle serves primarily as a type of delivery vehicle – a concentrated source of metal that transports the bio-active ion to tissue or intracellular targets that would not be accessible to the ion alone.  This talk describes recent research on the bio-environmental behavior of metal-containing nanoparticles that include carbon nanotubes, nano-nickel, and nano-silver.  The talk will discuss the origin and release kinetics of free metal ions, purification methods, and environmental persistence.   In the case of nano-silver, mechanistic insight into ion formation will be used to develop and demonstrate “controlled release” formulations, in which ligands, coatings, and oxide films are used to engineer the ion release rate and tune the antibacterial activity.