title: Molecular imaging techniques to study the biodistribution of orally administered (99m)Tc-labelled naive and ligand-tagged nanoparticles.
abstract: OBJECTIVE
  Study by molecular imaging the biodistribution of poly(anhydride) nanoparticles after oral administration.
  
  
  METHODS
  Poly (anhydride) nanoparticles (NP) and cyclodextrin-tagged nanoparticles (CD-NP) were radiolabelled with (99m)Tc. Radiochemical purity was measured with a double-solvent chromatography system and the absence of undesirable components was confirmed by size and polydispersion measurement of the technetium-labelled nanoparticles by photon correlation spectroscopy. Single photon emission computed tomography (SPECT) fused computed tomography (CT) in vivo molecular imaging was used for biodistribution studies in small animals.
  
  
  RESULTS
  SPECT-CT images revealed activity only in the gastrointestinal tract. Thirteen percent of the given dose of CD-NP and 3% of the given dose of conventional NP were found in the stomach at 8 h.
  
  
  CONCLUSIONS
  No evidence of translocation or distribution out of gastrointestinal tract was found. CD-NP moved significantly more slowly inside the gut than conventional NP, probably due to their physico-chemical structure that allows stronger interactions with the gut mucosa.
authors.affiliation: Department of Nuclear Medicine, Clínica Universidad de Navarra, University Clinic of Navarra, Pamplona, Spain.
authors.forename: Paloma
authors.initials: P
authors.lastname: Areses
authors.forename: Ma Teresa
authors.initials: MT
authors.lastname: Agüeros
authors.forename: Gemma
authors.initials: G
authors.lastname: Quincoces
authors.forename: María
authors.initials: M
authors.lastname: Collantes
authors.forename: José Ángel
authors.initials: JÁ
authors.lastname: Richter
authors.forename: Luisa Ma
authors.initials: LM
authors.lastname: López-Sánchez
authors.forename: María
authors.initials: M
authors.lastname: Sánchez-Martínez
authors.forename: Juan M
authors.initials: JM
authors.lastname: Irache
authors.forename: Iván
authors.initials: I
authors.lastname: Peñuelas
mesh_terms: D000284:Administration, Oral; D000818:Animals; D003505:Cyclodextrins / Q000737:chemistry; D005612:Freeze Drying; D005746:Gastric Emptying; D008024:Ligands; D008297:Male; D057054:Molecular Imaging / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011786:Quality Control; D051381:Rats; D017208:Rats, Wistar; D013057:Spectrum Analysis; D013667:Technetium / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed
chemical_list: D003505:Cyclodextrins; D008024:Ligands; D013667:Technetium