The use of cellular magnetic resonance imaging to track the fate of iron-labeled multipotent stromal cells after direct transplantation in a mouse model of spinal cord injury.
OBJECTIVE
The objective of this study was to track the fate of iron-labeled, multipotent stromal cells (MSC) after their direct transplantation into mice with spinal cord injuries using magnetic resonance imaging (MRI).


METHODS
Mice with spinal cord injuries received a direct transplant of (1) live MSC labeled with micron-sized iron oxide particles (MPIO); (2) dead, MPIO-labeled MSC; (3) unlabeled MSC; or (4) free MPIO and were imaged at 3 T for 6 weeks after transplantation.


RESULTS
Live, iron-labeled MSC appeared as a well-defined region of signal loss in the mouse spinal cord at the site of transplant. However, the MR appearance of dead, iron-labeled MSC and free iron particles was similar and persisted for the 6 weeks of the study.


CONCLUSIONS
Iron-labeled stem cells can be detected and monitored in vivo after direct transplantation into the injured spinal cord of mice. However, the fate of the iron label is not clear. Our investigation indicates that caution should be taken when interpreting MR images after direct transplantation of iron-labeled cells.
Gonzalez-Lara
Laura E
LE
Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada. gonzalez@imaging.robarts.ca
Xu
Xiaoyun
X
Hofstetrova
Klara
K
Pniak
Anna
A
Chen
Yuhua
Y
McFadden
Catherine D
CD
Martinez-Santiesteban
Francisco M
FM
Rutt
Brian K
BK
Brown
Arthur
A
Foster
Paula J
PJ
D000818:Animals; D004195:Disease Models, Animal; D011992:Endosomes / Q000378:metabolism / Q000648:ultrastructure; D005434:Flow Cytometry; D007501:Iron / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D039902:Multipotent Stem Cells / Q000166:cytology / Q000378:metabolism / Q000637:transplantation* / Q000648:ultrastructure; D013119:Spinal Cord Injuries / Q000473:pathology / Q000628:therapy*; D013194:Staining and Labeling; D033581:Stem Cell Transplantation; D017154:Stromal Cells / Q000166:cytology / Q000378:metabolism / Q000637:transplantation / Q000648:ultrastructure
D007501:Iron