title: Excretion and toxicity of gold-iron nanoparticles.
abstract: Though gold nanoparticles have been considered bio-inert, recent studies have questioned their safety. To reduce the potential for toxicity, we developed a nanoclustering of gold and iron oxide as a nanoparticle (nanorose) which biodegrades into subunits to facilitate rapid excretion. In this present study, we demonstrate acid and macrophage lysosomal degradation of nanorose via loss of the near-infrared optical shift, and clearance of the nanorose in vivo following i.v. administration in C57BL/6 mice by showing gold concentration is significantly reduced in 11 murine tissues in as little as 31 days (P < 0.01). Hematology and chemistry show no toxicity of nanorose injected mice up to 14 days after administration. We conclude that the clustering design of nanorose does enhance the excretion of these nanoparticles, and that this could be a viable strategy to limit the potential toxicity of gold nanoparticles for clinical applications.
  
  
  BACKGROUND
  The potential toxicity of nanomaterials is a critically important limiting factor in their more widespread clinical application. Gold nanoparticles have been classically considered bio-inert, but recent studies have questioned their safety. The authors of this study have developed a clustering gold and iron oxide nanoparticle (nanorose), which biodegrades into subunits to facilitate rapid excretion, resulting in reduced toxicity.
authors.affiliation: Division of Cardiology, Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229, USA.
authors.forename: James T
authors.initials: JT
authors.lastname: Jenkins
authors.forename: David L
authors.initials: DL
authors.lastname: Halaney
authors.forename: Konstantin V
authors.initials: KV
authors.lastname: Sokolov
authors.forename: Li L
authors.initials: LL
authors.lastname: Ma
authors.forename: Heather J
authors.initials: HJ
authors.lastname: Shipley
authors.forename: Smridhi
authors.initials: S
authors.lastname: Mahajan
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Louden
authors.forename: Reto
authors.initials: R
authors.lastname: Asmis
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Milner
authors.forename: Keith P
authors.initials: KP
authors.lastname: Johnston
authors.forename: Marc D
authors.initials: MD
authors.lastname: Feldman
mesh_terms: D000143:Acids / Q000737:chemistry; D000818:Animals; D002478:Cells, Cultured; D006046:Gold / Q000008:administration & dosage / Q000633:toxicity*; D006863:Hydrogen-Ion Concentration; D007275:Injections, Intravenous; D007501:Iron / Q000008:administration & dosage / Q000633:toxicity*; D008027:Light; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D053768:Metal Nanoparticles / Q000008:administration & dosage / Q000633:toxicity* / Q000648:ultrastructure; D051379:Mice; D008810:Mice, Inbred C57BL; D012542:Scattering, Radiation; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors; D018675:Toxicity Tests
chemical_list: D000143:Acids; D012996:Solutions; D006046:Gold; D007501:Iron