title: Estimating the effective density of engineered nanomaterials for in vitro dosimetry.
abstract: The need for accurate in vitro dosimetry remains a major obstacle to the development of cost-effective toxicological screening methods for engineered nanomaterials. An important key to accurate in vitro dosimetry is the characterization of sedimentation and diffusion rates of nanoparticles suspended in culture media, which largely depend upon the effective density and diameter of formed agglomerates in suspension. Here we present a rapid and inexpensive method for accurately measuring the effective density of nano-agglomerates in suspension. This novel method is based on the volume of the pellet obtained by benchtop centrifugation of nanomaterial suspensions in a packed cell volume tube, and is validated against gold-standard analytical ultracentrifugation data. This simple and cost-effective method allows nanotoxicologists to correctly model nanoparticle transport, and thus attain accurate dosimetry in cell culture systems, which will greatly advance the development of reliable and efficient methods for toxicological testing and investigation of nano-bio interactions in vitro.
authors.affiliation: 1] Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, Harvard School of Public Health, 655 Huntington Ave Boston, Massachusetts 02115, USA [2].
authors.forename: Glen
authors.initials: G
authors.lastname: DeLoid
authors.affiliation: 1] Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, Harvard School of Public Health, 655 Huntington Ave Boston, Massachusetts 02115, USA [2].
authors.forename: Joel M
authors.initials: JM
authors.lastname: Cohen
authors.affiliation: Division of Earth and Ocean Sciences, Nicholas School of the Environment, 207A Old Chemistry Building, Box 90227 Duke University, Durham, North Carolina 27708, USA.
authors.forename: Tom
authors.initials: T
authors.lastname: Darrah
authors.affiliation: National Institute for Occupational Safety and Health, Health Effects Laboratory Division, Pathology and Physiology Research Branch, Morgantown, West Virginia 26505, USA.
authors.forename: Raymond
authors.initials: R
authors.lastname: Derk
authors.affiliation: National Institute for Occupational Safety and Health, Health Effects Laboratory Division, Pathology and Physiology Research Branch, Morgantown, West Virginia 26505, USA.
authors.forename: Liying
authors.initials: L
authors.lastname: Rojanasakul
authors.affiliation: Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, Harvard School of Public Health, 655 Huntington Ave Boston, Massachusetts 02115, USA.
authors.forename: Georgios
authors.initials: G
authors.lastname: Pyrgiotakis
authors.affiliation: BASF SE, GMC/R-G201, 67056 Ludwigshafen, Germany.
authors.forename: Wendel
authors.initials: W
authors.lastname: Wohlleben
authors.affiliation: 1] Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, Harvard School of Public Health, 655 Huntington Ave Boston, Massachusetts 02115, USA [2].
authors.forename: Philip
authors.initials: P
authors.lastname: Demokritou
mesh_terms: D002460:Cell Line; D002477:Cells / Q000737:chemistry*; D004058:Diffusion; D006801:Humans; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D010316:Particle Size; D014461:Ultracentrifugation