Abstract
Background aims. Cell labeling with superparamagnetic iron oxide (SPIO) nanoparticles enables non-invasive tracking of transplanted cells. The aim of this study was to investigate whether SPIO nanoparticles have an effect on endothelial progenitor cell (EPC) functional activity and the feasibility of a protocol for labeling swine- and rat-origin EPC using SPIO nanoparticles at an optimized low dosage. Methods. EPC were isolated from the peripheral blood of swine and bone marrow of rat and characterized. After ex vivo cultivation, EPC were labeled with SPIO nanoparticles (to make a series of final concentrations, 50, 100, 200 and 400 μg/mL) or vehicle control. We also investigated the long-term effects of 200 μg/mL SPIO nanoparticles on EPC (4, 8, 12 and 16 days after labeling). The labeling efficiency was tested through Prussian blue (PB) staining and the intracellular iron uptake was also measured quantitatively and confirmed. EPC proliferation and migration were determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and transwell chamber assay, respectively. An EPC adhesion assay was performed by replating the cells on fibronectin-coated dishes and then counting the adherent cells. EPC apoptosis was evaluated using an Annexin V–FITC apoptosis kit. Results. SPIO nanoparticles impaired EPC migration and promoted EPC adhesion. EPC proliferation and apoptosis were not affected. SPIO nanoparticles could label EPC efficiently at 200 μg/mL overnight without significantly affecting EPC functional activity. Conclusions. SPIO nanoparticles impaired the EPC migration ability and promoted the EPC adhesion capacity. EPC could be labeled efficiently at an appropriate concentration (200 μg/mL) without significantly affecting their functional activity.
Acknowledgments
This research project has been partially supported by the National Natural Science Foundation of China (NSFC 30801500), Program for New Century Excellent Talents in University (NCET-08–0488), Zhejiang Provincial Natural Science Foundation of China (ZJNSF Y2080369) and Research Fund for the Doctoral Program of Higher Education (RFDP 20070335051).
Disclosure
We have no financial or personal relationships with other people or organizations to report that caused a conflict of interest in writing this paper.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.