磁共振示踪超小超顺磁性纳米铁颗粒标记大鼠C6脑胶质瘤细胞的效果分析

目的 监测不同浓度超小超顺磁性纳米铁颗粒（USPIO）对不同数量大鼠C6胶质瘤细胞离体及载体标记的效果。方法采用0、25、50μg／ml浓度的USPIO标记1×10^6,2×10^6和1×10^7大鼠C6胶质瘤细胞,离体MRI扫描T1WI,T2WI,GRE／30°序列成像,测定细胞群信号。0、25、50μg／ml^3种浓度USPIO标记1×10^6大鼠C6胶质瘤细胞后,立体定向分别接种于6只大鼠（每种浓度接种2只）的右侧额叶,载体MRI扫描T1,WI,T2WI,GRE／30°序列成像,测定其信号强度。结果不同数量的大鼠C6胶质瘤细胞与0、25、50μg／ml浓度的USPIO培养12h,离体MRI不同序列测定不同浓度USPIO标记相同数量的细胞群,GRE／30。和T2,WI测定的各组之间差异均有统计学意义,50与25μg／ml组与0μg／ml组比较,差异均有统计学意义（t=4．19与3．38,P〈0．05）;同一浓度USPIO标记大鼠C6胶质瘤细胞,信号强度与细胞数量有关（t=5．16,2．35,4．41;P〈0．05）。普鲁士蓝染色镜下观察,发现标记的细胞从25到50μg／ml染色程度逐渐加深。载体25μg/ml浓度的USPIO标记大鼠C6胶质瘤细胞在MRI成像中清楚显示病变的范围及信号强度。结论USPIO可以标记大鼠C6胶质瘤细胞。MRI的信号强度与同一浓度USPIO标记细胞的数量成反比,25μg／ml浓度USPIO标记的肿瘤细胞,活体接种脑内完全可以达到MRI示踪的目的。

MRI monitoring ultra-small superparamagnetic iron oxide (USPIO) particle labeling C6 rat glioma cells

OBJECTIVE: To monitor the effects of labeling C6 rat glioma cells with different concentrations of USPIO in vivo and in vitro. METHODS: C6 rat glioma cells of 1 x 10(6), 2 x 10(6) and 1 x 10(7) were labeled with 0 microg/ml, 25 microg/ml, 50 microg/ml USPIO, The signal intensity of cells were evaluated by MRI with T(1)WI, T(2)WI and GRE/30 degrees sequences in vitro. 1 x 10(6) of C6 glioma cells were labeled with 0 microg/ml, 25 microg/ml, 50 microg/ml USPIO and inoculated into the right frontal lobe of 2 rats under stereotaxis apparatus respectively (total 6 rats), Same MRI parameters were used just as above. Iron particle density and cells was measured by HE and Prussian blue stain under microscopy. RESULTS: Different cell population was cultured with 0 microg/ml, 25 microg/ml, 50 microg/ml USPIO about 12 hours. The MR signal intensity of labeling cells were inversely correlated with the different concentration of USPIO groups in T(2)W and GRE/30 degrees imaging (t = 4.19, 3.38, P < 0.05) in vitro. There was an inversely correlation between the labeling cell population and the signal intensity at the same concentration of USPIO (t = 5.16, 2.35, 4.41; P < 0.05). Dyeing degree of labeling cells stained by Prussion blue gradually deepened from 25 microg/ml to 50 microg/ml by microscopy. In vivo MRI can clearly show the cells labeled with 25 microg/ml USPIO. CONCLUSIONS: Iron particle density in the rat glioma cells were gradually increased with the concentration of USPIO. The MR signal intensity was inversely correlated with the cell population at the same condition. 25 microg/ml USPIO labeling rat glioma cells were enough for in vivo monitoring by MRI.