Direct labeling of hMSC with SPIO: the long-term influence on toxicity, chondrogenic differentiation capacity, and intracellular distribution.
OBJECTIVE
The purpose of this study was to evaluate the long-term cellular toxicity, labeling efficiency, chondrogenic differentiation capacity, and intracellular distribution following direct superparamagnetic iron oxide (SPIO) nanoparticle labeling of human mesenchymal stem cells (hMSCs) in the absence of transfection agents.


METHODS
hMSCs were incubated with a SPIO, Ferucarbotran, at concentrations of 0, 1, 10, and 100 μg Fe/ml for 24 or 72 h. The cell granularity and size change, reactive oxygen species generation, and mitochondria membrane potential were measured by flow cytometry. The differentiation capacity of the cells into chondrocytes was determined by Alcian blue and Safranin-O staining, immunocytochemical analysis, and reverse transcription polymerase chain reaction.


RESULTS
The intracellular distribution of the internalized particles was visualized via confocal microscopy. No significant difference was found in the toxicity of labeled cells relative to controls. Successful chondrogenesis of Ferucarbotran-labeled hMSCs was confirmed. The intracellular SPIO nanoparticles were located within the lysosomes.


CONCLUSIONS
In conclusion, we have demonstrated the feasibility of direct labeling with Ferucarbotran without impairment of cellular function, toxicity, or inhibition of differentiation capacity. Furthermore, lysosomal metabolism takes place after intracellular uptake of Ferucarbotran.
Yang
Chung-Yi
CY
Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.|Department of Medical Imaging, National Taiwan University Hospital Yun-Lin Branch, Douliu, Taiwan.|Department of Medical Imaging, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
Hsiao
Jong-Kai
JK
Department of Medical Imaging, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
Tai
Ming-Fong
MF
Department of Physics, National Tsing Hua University, No. 101 Sec. 2, Kuang Fu Road, Hsinchu, 300, Taiwan.
Chen
Shin-Tai
ST
Department of Biochemistry, Musculoskeletal Disease Center, J.L. Pettis VA Medical Center, Loma Linda University, Loma Linda, CA, 92357, USA.
Cheng
Hui-Ying
HY
Department of Medical Imaging, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
Wang
Jaw-Lin
JL
Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.
Liu
Hon-Man
HM
Department of Medical Imaging, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. hmliu@ntu.edu.tw.|Department of Radiology, National Taiwan University Hospital and College of Medicine, 7 Chung-Shan South Road, Taipei, Taiwan. hmliu@ntu.edu.tw.
D002454:Cell Differentiation / Q000187:drug effects*; D020219:Chondrogenesis / Q000187:drug effects*; D003911:Dextrans / Q000633:toxicity*; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism*; D058185:Magnetite Nanoparticles / Q000633:toxicity*; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D018613:Microscopy, Confocal; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013194:Staining and Labeling; D013997:Time Factors
D003911:Dextrans; D016326:Extracellular Matrix Proteins; D058185:Magnetite Nanoparticles; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; C065507:ferumoxides