The major goal of this project is to examine the link between physiochemical properties of engineered nanomaterials (ENMs) and biological effects. Engineered nanomaterials (ENMs) have novel physical and chemical properties, stemming from their nanometer-scale size, and can undergo dynamic changes (e.g., agglomeration, aggregation, and oxidation) when interacting with biological systems. Nano-silver and carbon are used as model ENMs. The theme of the Center is ENMs’ respiratory effects and their interaction with lung surfactants using a systematic, integrated, multidisciplinary approach to produce mechanism-driven toxicological data that will be used in a mechanism-based risk analysis framework for ENMs. This Center grant contains an R01 project using in vitro approaches, an R01 projects using in vivo animal approaches, and an R21 project using computational approaches to estimate the health risk. These projects are integrated through an administrative core and a science core as well.