title: Magnetic tagging of cell-derived microparticles: new prospects for imaging and manipulation of these mediators of biological information.
abstract: OBJECTIVE
  Submicron membrane fragments termed microparticles (MPs), which are released by apoptotic or activated cells, are newly considered as vectors of biological information and actors of pathology development. We propose the tagging of MPs with magnetic nanoparticles as a new approach allowing imaging, manipulation and targeting of cell-derived MPs.
  
  
  METHODS
  MPs generated in vitro from human endothelial cells or isolated from atherosclerotic plaques were labeled using citrate-coated 8 nm iron-oxide nanoparticles. MPs were tagged with magnetic nanoparticles on their surface and detected as Annexin-V positive by flow cytometry.
  
  
  RESULTS
  Labeled MPs could be mobilized, isolated and manipulated at a distance in a magnetic field gradient. Magnetic mobility of labeled MPs was quantified by micromagnetophoresis. Interactions of labeled MPs with endothelial cells could be triggered and modulated by magnetic guidance. Nanoparticles served as tracers at different scales: at the subcellular level by electron microscopy, at the cellular level by histology and at the macroscopic level by MRI.
  
  
  CONCLUSIONS
  Magnetic labeling of biogenic MPs opens new prospects for noninvasive monitoring and distal manipulations of these biological effectors.
authors.affiliation: Laboratoire Matière et Systèmes Complexes, UMR 7057, CNRS & Université Paris Diderot, 10 Rue Alice Domon et Léonie Duquet, 75205 Paris cedex 13, France.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Vats
authors.forename: Claire
authors.initials: C
authors.lastname: Wilhelm
authors.forename: Pierre-Emmanuel
authors.initials: PE
authors.lastname: Rautou
authors.forename: Marie
authors.initials: M
authors.lastname: Poirier-Quinot
authors.forename: Christine
authors.initials: C
authors.lastname: Péchoux
authors.forename: Cécile
authors.initials: C
authors.lastname: Devue
authors.forename: Chantal M
authors.initials: CM
authors.lastname: Boulanger
authors.forename: Florence
authors.initials: F
authors.lastname: Gazeau
mesh_terms: D017304:Annexin A5 / Q000378:metabolism; D050197:Atherosclerosis / Q000473:pathology*; D002460:Cell Line; D055252:Cell-Derived Microparticles / Q000378:metabolism* / Q000473:pathology; D019343:Citric Acid / Q000737:chemistry; D042783:Endothelial Cells / Q000166:cytology*; D005290:Ferric Compounds; D005434:Flow Cytometry; D006801:Humans; D008279:Magnetic Resonance Imaging; D008280:Magnetics; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000648:ultrastructure
chemical_list: D017304:Annexin A5; D005290:Ferric Compounds; C000499:ferric oxide; D019343:Citric Acid