title: Barrier capacity of human placenta for nanosized materials.
abstract: BACKGROUND
  Humans have been exposed to fine and ultrafine particles throughout their history. Since the Industrial Revolution, sources, doses, and types of nanoparticles have changed dramatically. In the last decade, the rapidly developing field of nanotechnology has led to an increase of engineered nanoparticles with novel physical and chemical properties. Regardless of whether this exposure is unintended or not, a careful assessment of possible adverse effects is needed. A large number of projects have been carried out to assess the consequences of combustion-derived or engineered nanoparticle exposure on human health. In recent years there has been a growing concern about the possible health influence of exposure to air pollutants during pregnancy, hence an implicit concern about potential risk for nanoparticle exposure in utero. Previous work has not addressed the question of whether nanoparticles may cross the placenta.
  
  
  OBJECTIVE
  In this study we investigated whether particles can cross the placental barrier and affect the fetus.
  
  
  METHODS
  We used the ex vivo human placental perfusion model to investigate whether nanoparticles can cross this barrier and whether this process is size dependent. Fluorescently labeled polystyrene beads with diameters of 50, 80, 240, and 500 nm were chosen as model particles.
  
  
  RESULTS
  We showed that fluorescent polystyrene particles with diameter up to 240 nm were taken up by the placenta and were able to cross the placental barrier without affecting the viability of the placental explant.
  
  
  CONCLUSIONS
  The findings suggest that nanomaterials have the potential for transplacental transfer and underscore the need for further nanotoxicologic studies on this important organ system.
authors.affiliation: Empa, Swiss Federal Laboratories for Material Testing and Research, Laboratory for Materials-Biology Interactions, St. Gallen, Switzerland. peter.wick@empa.ch
authors.forename: Peter
authors.initials: P
authors.lastname: Wick
authors.forename: Antoine
authors.initials: A
authors.lastname: Malek
authors.forename: Pius
authors.initials: P
authors.lastname: Manser
authors.forename: Danielle
authors.initials: D
authors.lastname: Meili
authors.forename: Xenia
authors.initials: X
authors.lastname: Maeder-Althaus
authors.forename: Liliane
authors.initials: L
authors.lastname: Diener
authors.forename: Pierre-Andre
authors.initials: PA
authors.lastname: Diener
authors.forename: Andreas
authors.initials: A
authors.lastname: Zisch
authors.forename: Harald F
authors.initials: HF
authors.lastname: Krug
authors.forename: Ursula
authors.initials: U
authors.lastname: von Mandach
mesh_terms: D004781:Environmental Exposure / Q000032:analysis*; D005260:Female; D005333:Fetus / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D008431:Maternal-Fetal Exchange / Q000502:physiology; D008954:Models, Biological; D053758:Nanoparticles / Q000032:analysis / Q000737:chemistry*; D010316:Particle Size; D010477:Perfusion; D010539:Permeability; D010920:Placenta / Q000187:drug effects / Q000378:metabolism*; D011137:Polystyrenes / Q000737:chemistry* / Q000493:pharmacokinetics* / Q000494:pharmacology; D011247:Pregnancy
chemical_list: D011137:Polystyrenes