活体MR成像监测移植干细胞治疗SD大鼠心肌梗死并评价左心功能的可行性研究

目的 以超小超顺磁性氧化铁(USPIO)标记SD大鼠脂肪来源干细胞(ADSCs),探讨临床型1.5 T MR扫描仪活体示踪SD大鼠急性心梗后心肌注射USPIO标记的干细胞并同时评估心功能的可行性.方法 USPIO 40 μg Fe/ml、多聚赖氨酸(poly-l-lysine,PLL) 1.5 μg/ml与ADSCs共...

Magnetic resonance imaging of injected adipose derived stem cells (ADSCs) in rat myocardial infarction: the feasibility of cell tracking and left ventricular function measurement in vivo

Objective： To evaluate the feasibility of tracing the ultrasmall superparamagnetic iron oxide （USPIO） labled adipose derived stem cells （ADSCs） in vivo with clinical 1.5 T MR scanner. Methods and Materials： ADSCs were incubated with culture medium containing 40 μg/ml USPIO and 1.5 μg/ml poly-1-1ysine （PLL） for 24 h. The distribution of iron particles in cells was determined by Prussian blue staining and transmission electron microscopy （TEM）. MTS was used to assess the viability of USPIO labeled stem cells. The anterior descending coronary artery （LAD） of the rats in experimental group （n=1 0） were ligated to establish the acute myocardial infarction model. The labeled ADSCs were directlty injected into the myocardium. In vivo, MR imaging was performed with FIESTA Cine, FSPGR Cine, and 2D MDE sequences both for rats in experimental group and those in control group （n=5）. The left-ventricular end-diastolic volume （LVEDV）, left-ventricular end-systolic volume （LVESV）, and left-ventricular ejection fraction （LVEF） were calculated on Report Card Workstastion. Postmortal study was carried out to determine the distribution of USPIO particles in the myocadium with Prussian blue stain. Results： After incubating the stem cells with USPIO and PLL for 24h, the percentage of labeled ADSCs reached over 99%. Iron particles in the stem cells were confirmed by TEM, which was mainly in lysosomes. MTS experiments revealed that USPIO （10, 20, 40, 80, 160 μg Fe/ml） exerted insignificant influence on the proliferation of ADSCs. The acute myocardial infarction animal model was successfully established by ligating LAD for all the 10 SD rats. The signal intensity of myocardium significantly decreased both on FIESTA Cine and FSPGR Cine images after injection of USPIO labeled stem cells. In addition, the ventrical wall motion abnormalities were found on cine images of rats in experimental group. Delay enhancement was observed at the regions with motion abnormalities. The LVEDV, LVESV, and LVEF were 0.52 ±0.05 ml, 0.20 ± 0.03 ml, and 61 .0 ± 4.3% for rats in control group, and 0.44 ± 0.04 ml, 0.25 ± 0.05 ml, and 42.7 ± 13.4% for rats in experimental group, respectively. The LVEF and LVEDV were significant different between two groups （P〈0.05）. The USPIO particles were found around infracted myocardium by Prussian blue staining. Conclusion： In vivo, it is feasible to track the USPIO labled stem cells in the infarcted myocardium and to evaluate the motion function of left ventricular wall of SD rats by clinical 1.5 T MR imaging.