ABSTRACT
<p><b>OBJECTIVE</b>To perform in vitro magnetic resonance imaging on magnetic iron oxide (Fe(2)O(3)-PLL) labeled rabbit peripheral blood endothelial progenitor cells (EPCs).</p><p><b>METHODS</b>Fe(2)O(3) was incubated with PLL for 2 hours to form Fe(2)O(3)-PLL. Rabbit peripheral blood mononuclear cells (MNCs) were isolated and EPCs were selected by adherence method, expanded and incubated with Fe(2)O(3)-PLL. Intracellular iron was detected by Prussian blue stain and under electron microscope. MTT assay was used to evaluate cell survival and proliferation of Fe(2)O(3)-PLL labeled EPCs. Flow cytometry was used to analysis cell cycle and apoptosis. The cells underwent in vitro MR imaging with various sequences.</p><p><b>RESULTS</b>Iron-containing intracytoplasmatic vesicles could be observed clearly with Prussian blue staining and electron microscope observation. Survival, life cycle and apoptosis values obtained by MTT and flow cytometry analysis were similar among unlabelled EPCs and EPCs labeled with various concentrations Fe(2)O(3)-PLL. The signal intensity on MRI was significantly decreased in labeled cells compared with that in unlabeled cells. The percentage change in signal intensity (DeltaSI) was most significant on T(2)*WI and DeltaSI was significantly lower in cells labeled for 7 days than that labeled for 1 day.</p><p><b>CONCLUSIONS</b>The rabbit peripheral blood EPCs can be labeled with Fe(2)O(3)-PLL without significant change in viability and proliferation. The labeled EPCs can be imaged with standard 1.5 T MR equipment. The degree of MR signal decreasing may indirectly reflect the cells count, growth state and division.</p>
Subject(s)
Animals , Male , Rabbits , Biomarkers , Blood Cells , Cells, Cultured , Endothelial Cells , Cell Biology , Ferric Compounds , Magnetic Resonance Imaging , Methods , Stem Cells , Cell BiologyABSTRACT
Objective To investigate homografting vascular endothelial progenitor cells(EPCs)for preventing restenosis formation of carotid artery in New Zealand white rabbit models.Methods EPCs of New Zealand white rabbits were isolated,confirmed and expanded though the injured carotid arterial endothelium of rabbit model induced by dilatation with a 2.5 F balloon;and then EPCs were transplanted into the injured endothelium of the cells transplantation group(n=13,3 of them were transplanted with fluorencently-labeled- EPCs),while equal volume of saline without EPCs was injected into the injured endothelium in the control group(n=8).Histopathology was performed at 4 days after transplantation for the 2 rabbits,with fluorencently-labeled-EPCs.All of the rest remained rabbits were killed 4 weeks later for histological examinations.Results The histopathological slides showed that the fluorescence-positive expression existed in the injured endothelium 4 days after transplantation.At 4 weeks after the EPCs transplantation,there were less restenosis and less vascular wall thickening in the rabbits of cells transplantation group than those of the control group(P＜0.01).Conclusion The local interventional homografting heterogeneous endothelial progenitor cells can prevent restenosis after the carotid artery angioplasty in New Zealand White rabbit model. (J Intervent Radiol,2007,16:95-98)