title: MRI tracking of macrophages labeled with glucan particles entrapping a water insoluble paramagnetic Gd-based agent.
abstract: OBJECTIVE
  This study is aimed at demonstrating the in vivo potential of Gd(III)-loaded glucan particles (Gd-GPs) as magnetic resonance imaging (MRI)-positive agents for labeling and tracking phagocytic cells.
  
  
  METHODS
  GPs were obtained from Saccharomyces cerevisae and loaded with the water-insoluble complex Gd-DOTAMA(C18)2. The uptake kinetics of Gd-GPs by murine macrophages was studied in vitro and the internalization mechanism was assessed by competition assays. The in vivo performance of Gd-GPs was tested at 7.05 T on a mouse model of acute liver inflammation.
  
  
  RESULTS
  The minimum number of Gd-GPs-labeled J774.A1 macrophages detected in vitro by MRI was ca. 300 cells/μl of agar, which is the lowest number ever reported for cells labeled with a positive T1 agent. Intravenous injection of macrophages labeled with Gd-GPs in a mouse model of liver inflammation enabled the MRI visualization of the cellular infiltration in the diseased area.
  
  
  CONCLUSIONS
  Gd-GPs represent a promising platform for tracking macrophages by MRI as a T1 alternative to the golden standard T2-based iron oxide particles.
authors.affiliation: Department of Molecular Biotechnology and Health Sciences and Molecular and Preclinical Imaging Centers, University of Turin, Turin, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Figueiredo
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Cutrin
authors.forename: Silvia
authors.initials: S
authors.lastname: Rizzitelli
authors.forename: Elisa
authors.initials: E
authors.lastname: De Luca
authors.forename: João Nuno
authors.initials: JN
authors.lastname: Moreira
authors.forename: Carlos F G C
authors.initials: CF
authors.lastname: Geraldes
authors.forename: Silvio
authors.initials: S
authors.lastname: Aime
authors.forename: Enzo
authors.initials: E
authors.lastname: Terreno
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D058948:Cell Tracking / Q000379:methods*; D004705:Endocytosis; D005290:Ferric Compounds; D005453:Fluorescence; D005682:Gadolinium; D005936:Glucans; D006571:Heterocyclic Compounds; D008099:Liver / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D009942:Organometallic Compounds; D051381:Rats; D012441:Saccharomyces cerevisiae; D012995:Solubility; D013154:Spleen / Q000378:metabolism; D013194:Staining and Labeling; D014867:Water / Q000737:chemistry
chemical_list: D005290:Ferric Compounds; D005936:Glucans; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C062402:gadoteridol; D014867:Water; C000499:ferric oxide; D005682:Gadolinium