Labeling of human mesenchymal stromal cells with superparamagnetic iron oxide leads to a decrease in migration capacity and colony formation ability.
OBJECTIVE
Labeling of stem cells is crucial to allow tracking of stem cell homing and engraftment after transplantation. In this study we evaluated the influence of cell labeling procedures using clinically approved small particles of iron oxide (SPIO) with or without transfection reagents (TA) on functional parameters of human mesenchymal stem cells (MSC).


METHODS
The study was approved by the institutional review board of the University of Tubingen, Germany. Seven populations of bone marrow (BM)-derived human mesenchymal stem cells (MSC) were labeled with SPIO alone or in combination with various TA. Directly after labeling and two passages after labeling migration assays, quantification of colony-forming units and quantitative evaluation of the differentiation potential were performed. Quantification of the cellular total iron load (TIL), determination of the cellular viability and electron microscopy were also performed.


RESULTS
Labeling of mesenchymal stem cells with SPIO with or without TA did not affect cell viability and differentiation potential significantly. SPIO in combination with TA coated the cellular surface directly after labeling but was incorporated into the cells after two passages. Labeling of mesenchymal stem cells with TA led to a significant decrease of migration capacity. This effect was abolished after two passages. Labeling with and without TA led to a significant decrease in colony formation ability. This effect could also be observed after two passages.


CONCLUSIONS
The observed decrease of migration capacity and colony-formation ability was not associated with either TIL or localization of particles of iron oxide. SPIO labeling with and without TA had functional effects on human mesenchymal stem cells by decreasing the migration capacity and colony-formation ability of the stem cells.
Schäfer
Richard
R
Institute of Clinical and Experimental Transfusion Medicine, University Hospital Tübingen, Germany.
Kehlbach
Rainer
R
Müller
Michaela
M
Bantleon
Rüdiger
R
Kluba
Torsten
T
Ayturan
Miriam
M
Siegel
Georg
G
Wolburg
Hartwig
H
Northoff
Hinnak
H
Dietz
Klaus
K
Claussen
Claus D
CD
Wiskirchen
Jakub
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D001854:Bone Marrow Cells / Q000187:drug effects / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002465:Cell Movement / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D003287:Contrast Media / Q000494:pharmacology*; D003911:Dextrans; D005260:Female; D052203:Ferrosoferric Oxide; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007501:Iron / Q000494:pharmacology*; D058185:Magnetite Nanoparticles; D008297:Male; D059630:Mesenchymal Stem Cells / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D010087:Oxides / Q000494:pharmacology*; D013194:Staining and Labeling / Q000379:methods*; D055815:Young Adult
D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; D007501:Iron; C065507:ferumoxides; D052203:Ferrosoferric Oxide