title: Toward safer multi-walled carbon nanotube design: Establishing a statistical model that relates surface charge and embryonic zebrafish mortality.
abstract: Given the increased utility and lack of consensus regarding carbon nanotube (CNT) environmental and human health hazards, there is a growing demand for guidelines that inform safer CNT design. In this study, the zebrafish (Danio rerio) model is utilized as a stable, sensitive biological system to evaluate the bioactivity of systematically modified and comprehensively characterized multi-walled carbon nanotubes (MWNTs). MWNTs were treated with strong acid to introduce oxygen functional groups, which were then systematically thermally reduced and removed using an inert temperature treatment. While 25 phenotypic endpoints were evaluated at 24 and 120 hours post-fertilization (hpf), high mortality at 24 hpf prevented further resolution of the mode of toxicity leading to mortality. Advanced multivariate statistical methods are employed to establish a model that identifies those MWNT physicochemical properties that best estimate the probability of observing an adverse outcome. The physicochemical properties considered in this study include surface charge, percent surface oxygen, dispersed aggregate size and morphology and electrochemical activity. Of the five physicochemical properties, surface charge, quantified as the point of zero charge (PZC), was determined as the best predictor of mortality at 24 hpf. From a design perspective, the identification of this property-hazard relationship establishes a foundation for the development of design guidelines for MWNTs with reduced hazard.
authors: a Department of Chemical and Environmental Engineering , Yale University , New Haven , CT , USA .
authors: Leanne M
authors: LM
authors: Gilbertson
authors: b School of Forestry and Environmental Studies, Yale University , New Haven , CT , USA , and.
authors: Fjodor
authors: F
authors: Melnikov
authors: c Environmental and Molecular Toxicology, Oregon State University , Corvallis , OR , USA.
authors: Leah C
authors: LC
authors: Wehmas
authors: b School of Forestry and Environmental Studies, Yale University , New Haven , CT , USA , and.
authors: Paul T
authors: PT
authors: Anastas
authors: c Environmental and Molecular Toxicology, Oregon State University , Corvallis , OR , USA.
authors: Robert L
authors: RL
authors: Tanguay
authors: a Department of Chemical and Environmental Engineering , Yale University , New Haven , CT , USA .|b School of Forestry and Environmental Studies, Yale University , New Haven , CT , USA , and.
authors: Julie B
authors: JB
authors: Zimmerman
mesh_terms: D000818:Animals; D004625:Embryo, Nonmammalian / Q000187:drug effects*; D016015:Logistic Models; D015233:Models, Statistical; D037742:Nanotubes, Carbon / Q000737:chemistry / Q000633:toxicity*; D013499:Surface Properties; D013696:Temperature; D015027:Zebrafish / Q000196:embryology
chemical_list: D037742:Nanotubes, Carbon
keywords: Carbon nanotube toxicity; predictive toxicity; property–hazard relationship; safe material design; zebrafish (Danio rerio)