title: Are they in or out? The elusive interaction between Qtracker ® 800 vascular labels and brain endothelial cells.
abstract: OBJECTIVE
  Qtracker(®)800 Vascular labels (Qtracker(®)800) are promising biomedical tools for high-resolution vasculature imaging; their effects on mouse and human endothelia, however, are still unknown.
  
  
  METHODS
  Qtracker(®)800 were injected in Balb/c mice, and brain endothelium uptake was investigated by transmission electron microscopy 3-h post injection. We then investigated, in vitro, the effects of Qtracker(®)800 exposure on mouse and human endothelial cells by calcium imaging.
  
  
  RESULTS
  Transmission electron microscopy images showed nanoparticle accumulation in mouse brain endothelia. A subset of mouse and human endothelial cells generated intracellular calcium transients in response to Qtracker(®)800.
  
  
  CONCLUSIONS
  Qtracker(®)800 nanoparticles elicit endothelial functional responses, which prompts biomedical safety evaluations and may bias the interpretation of experimental studies involving vascular imaging.
authors.affiliation: Section of Anatomy & Histology, Department of Neurological & Movement Sciences, University of Verona, Verona 37134, Italy.|Department of Anatomy, Animal Physiology & Biophysics, Faculty of Biology, University of Bucharest, Bucharest 050095, Romania.
authors.forename: Beatrice Mihaela
authors.initials: BM
authors.lastname: Radu
authors.affiliation: Section of Anatomy & Histology, Department of Neurological & Movement Sciences, University of Verona, Verona 37134, Italy.|Department of Life & Environmental Physics, 'Horia Hulubei' National Institute for Physics & Nuclear Engineering, Magurele 077125, Romania.
authors.forename: Mihai
authors.initials: M
authors.lastname: Radu
authors.affiliation: Section of Anatomy & Histology, Department of Neurological & Movement Sciences, University of Verona, Verona 37134, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Tognoli
authors.affiliation: Section of Anatomy & Histology, Department of Neurological & Movement Sciences, University of Verona, Verona 37134, Italy.
authors.forename: Donatella
authors.initials: D
authors.lastname: Benati
authors.affiliation: Section of Anatomy & Histology, Department of Neurological & Movement Sciences, University of Verona, Verona 37134, Italy.
authors.forename: Flavia
authors.initials: F
authors.lastname: Merigo
authors.affiliation: Department of Biotechnology, University of Verona, Verona 37134, Italy.
authors.forename: Michael
authors.initials: M
authors.lastname: Assfalg
authors.affiliation: Section of Internal Medicine, Department of Medicine, University of Verona, Verona 37134, Italy.
authors.forename: Erika
authors.initials: E
authors.lastname: Solani
authors.affiliation: Section of Internal Medicine, Department of Medicine, University of Verona, Verona 37134, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Stranieri
authors.affiliation: Department of Biotechnology, University of Verona, Verona 37134, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Ceccon
authors.affiliation: Section of Internal Medicine, Department of Medicine, University of Verona, Verona 37134, Italy.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Fratta Pasini
authors.affiliation: Section of Internal Medicine, Department of Medicine, University of Verona, Verona 37134, Italy.
authors.forename: Luciano
authors.initials: L
authors.lastname: Cominacini
authors.affiliation: IRCCS Centro Neurolesi 'Bonino Pulejo', Messina, Italy.
authors.forename: Placido
authors.initials: P
authors.lastname: Bramanti
authors.affiliation: Section of Anatomy & Histology, Department of Neurological & Movement Sciences, University of Verona, Verona 37134, Italy.|IRCCS Centro Neurolesi 'Bonino Pulejo', Messina, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Osculati
authors.affiliation: Section of Anatomy & Histology, Department of Neurological & Movement Sciences, University of Verona, Verona 37134, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bertini
authors.affiliation: Section of Anatomy & Histology, Department of Neurological & Movement Sciences, University of Verona, Verona 37134, Italy.
authors.forename: Paolo Francesco
authors.initials: PF
authors.lastname: Fabene
mesh_terms: D000818:Animals; D001921:Brain / Q000648:ultrastructure*; D002118:Calcium / Q000737:chemistry; D058948:Cell Tracking / Q000379:methods; D003593:Cytoplasm / Q000648:ultrastructure; D042783:Endothelial Cells / Q000648:ultrastructure*; D004730:Endothelium, Vascular / Q000648:ultrastructure*; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D051379:Mice; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000648:ultrastructure*
chemical_list: D002118:Calcium
keywords: calcium imaging; cytosolic calcium transients; human umbilical vein endothelial cells; mouse brain endothelium; nanoparticle uptake; nanoparticles; transmission electron microscopy