Ferumoxide-PLL标记人骨髓间充质干细胞及其对磁共振成像信号的影响

Experimental study of Ferumoxide-PLL labeled human bone marrow mesenchymal stem cells in vitro and the effect on magnetic resonance imaging signals

目的研究超顺磁性氧化铁Ferumoxide和多聚赖氨酸(PLL)联合标记人骨髓间充质干细胞的可行性及其对体外磁共振成像信号的影响。方法应用50μg/mlFerumoxide-PLL标记人骨髓间充质干细胞,普鲁士蓝、台盼蓝染色检测细胞标记率及活细胞率;磁共振扫描仪计数Ferumoxide-PLL标记及未标记细胞数目,计算磁共振成像信号强度变化,经计算机软件拟合曲线计算弛豫时间和弛豫率。结果Ferumoxide-PLL标记的人骨髓间充质干细胞标记率为96%,活细胞率为97.60%;T2WWI检查显示信号强度平均下降53.45%。经计算机软件拟合曲线,计算得出Ferumoxide-PLL标记的人骨髓间充质干细胞弛豫时间为15.24ms,未标记细胞为79.88ms;Ferumoxide-PLL标记细胞的弛豫率为65.61/s,未标记细胞为12.52/s。标记细胞的弛豫率是未标记细胞的5.20倍。结论Ferumoxide-PLL可以高效标记人骨髓间充质干细胞,显著提高标记细胞的弛豫率,从而提供良好的对比度。

Objective To study the feasibility of Ferumoxide-PLL labeled human bone marrow mesenebymal stem cells （hBMSCs） and the effect on magnetic resonance imaging （MRI） signals in vitro. Methods hBMSCs were labeled with Ferumoxide-PLL （50μg/ml）. Prussian blue staining and trypan blue staining were used to determine the labeling efficiency of hBMSCs, and detect the rate of living cells. The labeled and unlabeled hBMSCs were examined with magnetic resonance scanner in vitro. The changes of MRI signals intensity （SI） were calculated. According to the fitting curve from computer, relaxation time and relaxation rate of labeled and unlabeled hBMSCs were calculated and compared. Results The labeling efficiency of labeled hBMSCs with Ferumoxide-PLL was 96%, while the rate of living cells was 97.60%. According to T2＊WI, SI decreased by an average of 53.45%. The relaxation time of the labeled and unlabeled hBMSCs was 15.24 ms and 79.88 ms respectively. The relaxation rate of the labeled and unlabeled hBMSCs was 65.61/s and 12.52/ s respectively. The relaxation rate of labeled cells was 5.20 times of unlabeled cells. Conclusion Ferumoxide-PLL can be used to label human bone marrow mesenchymal stem cells effectively, and it can obviously in- crease the relaxation rate of labeled cells, and provide as a good contrast.