Experimental study of endothelial progenitor cells labeled with superparamagnetic iron oxide in vitro

• Published in: Molecular medicine reports Vol. 11; no. 5; pp. 3814 - 3819
• Main Authors: WEI, MENG-QI, WEN, DI-DI, WANG, XIAO-YING, HUAN, YI, YANG, YONG, XU, JIAN, CHENG, KANG, ZHENG, MIN-WEN
• Format: Journal Article
• Language: English
• Published: Greece D.A. Spandidos 01.05.2015; Spandidos Publications; Spandidos Publications UK Ltd
• Subjects: acute myocardial infarction; Animals; Antigens; Apoptosis; Biological activity; Biomarkers; Bone marrow; Cell Proliferation; Cell Survival; Cell Tracking - methods; Centrifugation; Cytology; Efficiency; Electron microscopy; endothelial progenitor cells; Endothelial Progenitor Cells - cytology; Endothelial Progenitor Cells - metabolism; Endothelial Progenitor Cells - ultrastructure; Endothelium; Ferric Compounds; Ferric oxide; Flow cytometry; Genetic aspects; Growth factors; Heart attack; Heart attacks; Immunophenotyping; In Vitro Techniques; Injuries; Iron; Labeling; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Magnetite Nanoparticles; Morphology; Myocardial infarction; Nanoparticles; NMR; Nuclear magnetic resonance; Physiological aspects; Risk factors; Stem cells; Studies; superparamagnetic iron oxide; Swine; Swine, Miniature; China; United States > US
• ISSN: 1791-2997; 1791-3004
• DOI: 10.3892/mmr.2014.3122

Endothelial progenitor cells (EPCs) have an essential role in counteracting risk factor-induced endothelial injury and protecting against the development of vascular injury, such as myocardial infarction. Magnetic resonance imaging (MRI) was reported to be effective in tracking transplanted stem cells following cell-labeling with superparamagnetic iron oxide (SPIO) nanoparticles. SPIO has previously been used to label and track EPCs; however, the safest concentration of SPIO for labeling EPCs on a cellular level has remained to be elucidated. In addition, the optimum number of SPIO-labeled cells required to produce the highest quality magnetic resonance images has not yet been determined. In the present study, EPCs were isolated from the bone marrow of minipigs using density gradient centrifugation. Their biological activity was then studied using flow cytometric analysis. Cells were incubated at different concentrations of SPIO for different durations and then the growth curve, apoptosis, morphology and labeling efficiency of the EPCs were detected using optical and electron microscopy. T2-weighted fast spin-echo (T2WITSE) MRI of the different numbers of SPIO-labeled EPCs (35 μg/ml) were then obtained in axial and sagittal planes. The results of the present study demonstrated that EPCs were efficiently labeled with SPIO, with a labeling efficiency in each group of ~100% following incubation for 24 h. SPIO was found to be localized in the endosomal vesicles of EPCs, which was confirmed by electron microscopy. When the concentration of SPIO was <70 μg/ml, no significant differences were observed in cell viability, proliferative capability (P>0.05) and morphology between labeled and unlabeled EPCs. Furthermore, the T2WITSE signal intensity was significantly decreased in the groups of 5.0×105/ml and 1.0×105/ml compared with that of the control (P<0.05). In conclusion, the results of the present study indicated that 35 μg/ml was the most effective concentration of SPIO to label EPCs in vitro and acquire a high quality MRI. These findings may therefore contribute to the development of a promising novel therapeutic method for the treatment of myocardial infarction following autograft with SPIO-labeled EPCs in vivo.