title: Viability and MR detectability of iron labeled mesenchymal stem cells used for endoscopic injection into the porcine urethral sphincter.
abstract: Direct stem cell therapies for functionally impaired tissue require a sufficient number of cells in the target region and a method for verifying the fate of the cells in the subsequent time course. In vivo MRI of iron labeled mesenchymal stem cells has been suggested to comply with these requirements. The study was conducted to evaluate proliferation, migration, differentiation and adhesion effects as well as the obtained iron load of an iron labeling strategy for mesenchymal stem cells. After injection into the porcine urethral sphincter, the labeled cells were monitored for up to six months using MRI. Mesenchymal stem cells were labeled with ferucarbotran (60/100/200 µg/mL) and ferumoxide (200 µg/mL) for the analysis of migration and viability. Phantom MR measurements were made to evaluate effects of iron labeling. For short and long term studies, the iron labeled cells were injected into the porcine urethral sphincter and monitored by MRI. High resolution anatomical images of the porcine urethral sphincter were applied for detection of the iron particles with a turbo-spin-echo sequence and a gradient-echo sequence with multiple TE values. The MR images were then compared with histological staining. The analysis of cell function after iron labeling showed no effects on proliferation or differentiation of the cells. Although the adherence increases with higher iron dose, the ability to migrate decreases as a presumed effect of iron labeling. The iron labeled mesenchymal stem cells were detectable in vivo in MRI and histological staining even six months after injection. Labeling with iron particles and subsequent evaluation with highly resolved three dimensional data acquisition allows sensitive tracking of cells injected into the porcine urethral sphincter for several months without substantial biological effects on mesenchymal stem cells.
authors.affiliation: University of Tuebingen, Department of Diagnostic and Interventional Radiology, Section on Experimental Radiology, Tübingen, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Will
authors.affiliation: University of Tuebingen, Department of Diagnostic and Interventional Radiology, Section on Experimental Radiology, Tübingen, Germany.
authors.forename: Petros
authors.initials: P
authors.lastname: Martirosian
authors.affiliation: University of Tuebingen, Department of Diagnostic and Interventional Radiology, Section on Experimental Radiology, Tübingen, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Eibofner
authors.affiliation: University of Tuebingen, Department of Diagnostic and Interventional Radiology, Section on Experimental Radiology, Tübingen, Germany.
authors.forename: Fritz
authors.initials: F
authors.lastname: Schick
authors.affiliation: University of Tuebingen, Department of Diagnostic and Interventional Radiology, Tübingen, Germany.
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Bantleon
authors.affiliation: University of Tuebingen, Department of Urology, Laboratory of Tissue Engineering, Tübingen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Vaegler
authors.affiliation: University of Tuebingen, Department of Diagnostic and Interventional Radiology, Tübingen, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Grözinger
authors.affiliation: University of Tuebingen, Department of Diagnostic and Interventional Radiology, Tübingen, Germany.
authors.forename: Claus D
authors.initials: CD
authors.lastname: Claussen
authors.affiliation: University of Tuebingen, Department of Diagnostic and Interventional Radiology, Tübingen, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Kramer
authors.affiliation: University of Tuebingen, Department of Diagnostic and Interventional Radiology, Tübingen, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Schmehl
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D058948:Cell Tracking / Q000379:methods*; D003287:Contrast Media; D004724:Endoscopy / Q000379:methods; D007501:Iron; D008279:Magnetic Resonance Imaging / Q000379:methods*; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000502:physiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013194:Staining and Labeling / Q000379:methods; D013552:Swine; D014521:Urethra / Q000166:cytology* / Q000601:surgery
chemical_list: D003287:Contrast Media; D007501:Iron
keywords: MRI; SPIO labeling; mesenchymal stem cells; porcine urethral sphincter