title: Multimodality imaging demonstrates trafficking of liposomes preferentially to ischemic myocardium.
abstract: BACKGROUND
  Nanoparticles may serve as a promising means to deliver novel therapeutics to the myocardium following myocardial infarction. We sought to determine whether lipid-based liposomal nanoparticles can be shown through different imaging modalities to specifically target injured myocardium following intravenous injection in an ischemia-reperfusion murine myocardial infarction model.
  
  
  METHODS
  Mice underwent ischemia-reperfusion surgery and then either received tail-vein injection with gadolinium- and fluorescent-labeled liposomes or no injection (control). The hearts were harvested 24h later and underwent T1 and T2-weighted ex vivo imaging using a 7 Tesla Bruker magnet. The hearts were then sectioned for immunohistochemistry and optical fluorescent imaging.
  
  
  RESULTS
  The mean size of the liposomes was 100nm. T1-weighted signal intensity was significantly increased in the ischemic vs. the non-ischemic myocardium for mice that received liposomes compared with control. Optical imaging demonstrated significant fluorescence within the infarct area for the liposome group compared with control (163±31% vs. 13±14%, p=0.001) and fluorescent microscopy confirmed the presence of liposomes within the ischemic myocardium.
  
  
  CONCLUSIONS
  Liposomes traffic to the heart and preferentially home to regions of myocardial injury, enabling improved diagnosis of myocardial injury and could serve as a vehicle for drug delivery.
authors.affiliation: MedStar Heart and Vascular Institute, MedStar Washington Hospital Center, Washington, DC, USA. Electronic address: mjlipinski12@gmail.com.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lipinski
authors.affiliation: GIBI2(30), Grupo de Investigación Biomédica en Imagen, IIS La Fe, Valencia, Spain.
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Albelda
authors.affiliation: Departamento de Ciencias Biomédicas, Universidad CEU Cardenal Herrera, Valencia, Spain.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Frias
authors.affiliation: Advanced Cardiovascular Imaging Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Stasia A
authors.initials: SA
authors.lastname: Anderson
authors.affiliation: MedStar Heart and Vascular Institute, MedStar Washington Hospital Center, Washington, DC, USA.
authors.forename: Dror
authors.initials: D
authors.lastname: Luger
authors.affiliation: MedStar Heart and Vascular Institute, MedStar Washington Hospital Center, Washington, DC, USA.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Westman
authors.affiliation: MedStar Heart and Vascular Institute, MedStar Washington Hospital Center, Washington, DC, USA.
authors.forename: Ricardo O
authors.initials: RO
authors.lastname: Escarcega
authors.affiliation: MedStar Heart and Vascular Institute, MedStar Washington Hospital Center, Washington, DC, USA.
authors.forename: David G
authors.initials: DG
authors.lastname: Hellinga
authors.affiliation: MedStar Heart and Vascular Institute, MedStar Washington Hospital Center, Washington, DC, USA.
authors.forename: Ron
authors.initials: R
authors.lastname: Waksman
authors.affiliation: Advanced Cardiovascular Imaging Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Arai
authors.affiliation: MedStar Heart and Vascular Institute, MedStar Washington Hospital Center, Washington, DC, USA.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Epstein
mesh_terms: D000418:Albumins / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage / Q000493:pharmacokinetics*; D004195:Disease Models, Animal; D005456:Fluorescent Dyes / Q000008:administration & dosage / Q000493:pharmacokinetics*; D019786:Gadolinium DTPA / Q000008:administration & dosage / Q000493:pharmacokinetics*; D007150:Immunohistochemistry; D007275:Injections, Intravenous; D008081:Liposomes; D008279:Magnetic Resonance Imaging; D008297:Male; D051379:Mice; D008856:Microscopy, Fluorescence; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000378:metabolism; D015428:Myocardial Reperfusion Injury / Q000000981:diagnostic imaging* / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D053758:Nanoparticles; D061848:Optical Imaging / Q000379:methods*; D010316:Particle Size; D010714:Phosphatidylethanolamines / Q000008:administration & dosage / Q000493:pharmacokinetics*; D014018:Tissue Distribution
chemical_list: C571577:1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-(7-nitro-2-1,3-benzoxadiazol-4-yl); D000418:Albumins; D003287:Contrast Media; D005456:Fluorescent Dyes; D008081:Liposomes; D010714:Phosphatidylethanolamines; C058946:albumin-(gadolinium-DTPA); D019786:Gadolinium DTPA
keywords: Imaging; Liposome; Myocardial infarction; Nanoparticle