超顺磁性纳米铁颗粒标记许旺细胞及体外磁共振示踪的实验研究

目的 研究超顺磁性纳米铁颗粒(SPIO)体外标记小鼠许旺细胞(SCs)及MRI成像示踪的可行性.方法 分离、纯化新生C57BL/6小鼠(5～7 d)的许旺细胞,取已分别用25.0 μg/ml、50.0 μg/ml浓度SPIO标记的0.5×106、1.0×106、5.0×106个许旺细胞,普鲁士蓝染色和透射电镜观察标记细胞内铁颗粒的分布情况,并用不同MRI扫描序列,测定标记的细胞群信号.结果 0.5×106、1.0×106、5.0×106小鼠许旺细胞与不同浓度的SPIO共同培养24 h后,普鲁士蓝染色见细胞内有许多蓝染的铁颗粒;透射电镜检查显示致密的铁颗粒位于细胞的吞噬泡或溶酶体中.体外MRI呈明显的低信号改变,以T2WI和GRE/30°序列改变最为明显.结论 SPIO可以标记小鼠许旺细胞,应用MRI可以对其进行体外示踪和监测.

MRI monitoring superparamagnetic iron oxide (SPIO) particles labeling Schwann cells in vitro

Objective To investigate the effects of labeling Schwann cells with different concentrations of SPIO, and to investigate the feasibility of in vitro MR imaging. Methods The C57BL/6 mices'Schwann cells were isolated, purified, and then 0.5 × 106, 1.0 × 106, 5.0 × 106 cells were labeled with 25.0 μg/ml, 50.0 μg/ml SPIO. Prussian blue stain and transmission electron microscope (TEM) were performed for showing intracellular iron. The signal intensity of cells were evaluated by 3.0 MRI with different sequences in vitro. Results Different cell population (0.5 × 106, 1.0 × 106,5.0 × 106) were cultured with different concentration SPIO about 24 hours. Dyeing degree of labeling cells stained by Prussion blue gradually deepened from 25.0 μg/ml to 50.0 μg/ml. Transmission electron microscope indicated that iron particles accumulated inendosomes/lysosomes. The MR signal intensity of labeling cells were inversely correlated with the concentration of SPIO groups in T2WI and GRE/30° imaging in vitro. Conclusion Schwann cells could be labeled effectively with SPIO, and MRI could be used to monitor these labeled cells in vitro.