title: Tissue and cellular distribution of gold nanoparticles varies based on aggregation/agglomeration status.
abstract: OBJECTIVE
  The ability of nanoparticles to form larger superstructures of aggregates and agglomerates has been extensively noted in the literature. The in vivo biological impact of these structures, however, has not been assessed. This knowledge gap is especially critical in the safety assessment of nanoparticles to be used for therapeutic purposes.
  
  
  RESULTS
  Here we show that when administered intravenously into a mouse model, gold nanoparticle superstructures of reversible agglomerates and irreversible aggregates demonstrate significant differences in organ and cellular distribution compared with the primary particle building blocks. In addition, different structures produced different blood serum chemistry data.
  
  
  CONCLUSIONS
  These findings raise the possibility for different mechanisms of toxicity between the structures. Such a possibility necessitates complete characterization and stability assessment of nanomaterials prior to their in vivo administration.
authors.affiliation: US FDA, Center for Drug Evaluation & Research, Office of Testing & Research, Division of Drug Safety Research, Building 64 Room 2086 HFD 910, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA.
authors.forename: Athena M
authors.initials: AM
authors.lastname: Keene
authors.forename: David
authors.initials: D
authors.lastname: Peters
authors.forename: Rodney
authors.initials: R
authors.lastname: Rouse
authors.forename: Sharron
authors.initials: S
authors.lastname: Stewart
authors.forename: Elliot T
authors.initials: ET
authors.lastname: Rosen
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Tyner
mesh_terms: D000818:Animals; D001774:Blood Chemical Analysis; D004058:Diffusion; D005260:Female; D006046:Gold / Q000008:administration & dosage* / Q000737:chemistry*; D051379:Mice; D008807:Mice, Inbred BALB C; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry* / Q000648:ultrastructure; D009928:Organ Specificity; D010316:Particle Size; D014018:Tissue Distribution
chemical_list: D006046:Gold