title: Lipidots: competitive organic alternative to quantum dots for in vivo fluorescence imaging.
abstract: The use of fluorescent nanostructures can bring several benefits on the signal to background ratio for in vitro microscopy, in vivo small animal imaging, and image-guided surgery. Fluorescent quantum dots (QDs) display outstanding optical properties, with high brightness and low photobleaching rate. However, because of their toxic element core composition and their potential long term retention in reticulo-endothelial organs such as liver, their in vivo human applications seem compromised. The development of new dye-loaded (DiO, DiI, DiD, DiR, and Indocyanine Green (ICG)) lipid nanoparticles for fluorescence imaging (lipidots) is described here. Lipidot optical properties quantitatively compete with those of commercial QDs (QTracker(®)705). Multichannel in vivo imaging of lymph nodes in mice is demonstrated for doses as low as 2 pmols of particles. Along with their optical properties, fluorescent lipidots display very low cytotoxicity (IC(50) > 75 nM), which make them suitable tools for in vitro, and especially in vivo, fluorescence imaging applications.
authors.affiliation: CEA Grenoble, LETI-DTBS, MINATEC Campus, Grenoble, 38054 France.
authors.forename: Julien
authors.initials: J
authors.lastname: Gravier
authors.forename: Fabrice P
authors.initials: FP
authors.lastname: Navarro
authors.forename: Thomas
authors.initials: T
authors.lastname: Delmas
authors.forename: Frédérique
authors.initials: F
authors.lastname: Mittler
authors.forename: Anne-Claude
authors.initials: AC
authors.lastname: Couffin
authors.forename: Françoise
authors.initials: F
authors.lastname: Vinet
authors.forename: Isabelle
authors.initials: I
authors.lastname: Texier
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002470:Cell Survival; D003287:Contrast Media / Q000737:chemistry; D003952:Diagnostic Imaging / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D008198:Lymph Nodes / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D041681:NIH 3T3 Cells; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D010743:Phospholipids / Q000737:chemistry; D045663:Quantum Dots; D013024:Soybean Oil / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013501:Surface-Active Agents / Q000737:chemistry; D014018:Tissue Distribution
chemical_list: D003287:Contrast Media; D005456:Fluorescent Dyes; D010743:Phospholipids; D013501:Surface-Active Agents; D013024:Soybean Oil