title: Positron emission tomography based in-vivo imaging of early phase stem cell retention after intramyocardial delivery in the mouse model.
abstract: OBJECTIVE
  To establish PET as a tool for in-vivo quantification and monitoring of intramyocardially transplanted stem cells after labelling with FDG in mice with induced myocardial infarction.
  
  
  METHODS
  After inducing myocardial infarction in C57BL/6 mice, murine embryonic stem cells were labelled with FDG and transplanted into the border zone of the infarction. Dynamic PET scans were acquired from 25 to 120 min after transplantation, followed by a scan with 20 MBq FDG administered intravenously for anatomical landmarking. All images were reconstructed using the OSEM 3D and MAP reconstruction algorithms. FDG data were corrected for cellular tracer efflux and used as marker for cellular retention. FACS analysis of transplanted cells expressing enhanced green fluorescent protein was performed to validate the PET data.
  
  
  RESULTS
  We observed a rapid loss of cells from the site of transplantation, followed by stable retention over 120 min. Amounts of retention were 5.3 ± 1.1 % at 25 min, 5.0 ± 0.9 % at 60 min and 5.7 ± 1.2 % at 120 min. FACS analysis showed a high correlation without significant differences between the groups (P > 0.05). FDG labelling did not have any adverse effects on cell proliferation or differentiation.
  
  
  CONCLUSIONS
  Up-to-date imaging is a powerful method for tracking and quantifying intramyocardially transplanted stem cells in vivo in the mouse model. This revealed a massive cell loss within minutes, and thereafter a relatively stable amount of about 5 % remaining cells was observed. Our method may become crucial for further optimization of cardiac cell therapy in the widely used mouse model of infarction.
authors.affiliation: Reference and Translation Center for Cardiac Stem Cell Therapy (RTC), University of Rostock, 18057, Rostock, Germany.
authors.forename: Cajetan
authors.initials: C
authors.lastname: Lang
authors.forename: Sebastian
authors.initials: S
authors.lastname: Lehner
authors.forename: Andrei
authors.initials: A
authors.lastname: Todica
authors.forename: Guido
authors.initials: G
authors.lastname: Boening
authors.forename: Wolfgang-Michael
authors.initials: WM
authors.lastname: Franz
authors.forename: Peter
authors.initials: P
authors.lastname: Bartenstein
authors.forename: Marcus
authors.initials: M
authors.lastname: Hacker
authors.forename: Robert
authors.initials: R
authors.lastname: David
mesh_terms: D000818:Animals; D053595:Embryonic Stem Cells / Q000000981:diagnostic imaging / Q000187:drug effects / Q000637:transplantation*; D019788:Fluorodeoxyglucose F18 / Q000009:adverse effects / Q000493:pharmacokinetics; D051379:Mice; D008810:Mice, Inbred C57BL; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000601:surgery; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000009:adverse effects / Q000493:pharmacokinetics
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18