中文摘要：

目的使用超小超顺磁氧化铁颗粒（uSPIO）c对大鼠脂肪源间充质干细胞（ADSCs）进行体外标记，研究不同浓度的USPIO对大鼠ADSCs生物学活性的影响，确定其标记ADSCs的适宜浓度。方法实验分为8个组，其中6组依次添加不同终浓度的USPIO（180μg／mL、135μg／mL、90μg／mL、45μg／mL、22．5μg／mL、11．25μg／mL）。另2组为阴性转染组和空白对照组。普鲁士蓝染色检测USPl0标记ADSCs的效率，同时采用CCK-8及Alamarblue法检测各组细胞增殖情况。结果USPIO标记浓度在45μg/mL时，普鲁士蓝染色后ADSCs胞浆内可见大量蓝色颗粒，标记效率在95％以上；USPIO标记浓度在90μg／mL及以上时，标记效率约100％。CCK．8及Alamarblue检测结果表明USPl0在11-25μg/mL范围内对细胞活力的影响较小且差异无统计学意义（P〉0．05），故可将45—90μg／mL确定为适宜浓度。结论USPIO可在体外有效标记ADSCs，并且在适宜浓度范围内对细胞生物学活性无明显影响。

英文摘要：

Objective To label adipose-derived stromal cells （ADSCs） with different concentrations of ultrasmall superparamagnetic particles of iron oxide （USPIO） to investigate the biological characteristics of ADSCs treated with these USPIO, and determine the optimal concentration of USPIO in labeling ADSCs in vitro. Methods USPIO with different concentrations were prepared, and the particles were endocytosed by ADSCs generated from rat adipose tissue. Eight groups （negative control group, blank control group, and 11.25, 22.5, 45, 90, 135 and 180 μg/mL treatment groups） were chosen. Labeling efficiency and cellular uptake were analyzed by Prussian blue staining. Meanwhile, proliferation capacity and viability of ADSCs were evaluated by Alamar blue assay and Cell Counting kit-8. Results ADSCs could be effectively labeled with USPIO： approximately 95% ADSCs were labeled when they were incubated with USPIO for 24 h under the concentration of USPIO was 45 μg/mL; and approximately 100% ADSCs were labeled when the concentration of USPIO was 90 μg/mL and above. The CCK-8 and Alamar blue tests showed that USPIO of different concentrations （11.25-90 μg/mL） had little influence on cell growth viability, and no significant difference was noted between each 2 concentration groups （P〉0.05）. In a word, 45-90 μg/mL USPIO were the optimal choice for transplantion of ADSCs in vivo. Conclusion ADSCs from the adipose tissue can be effectively labeled with USPIO with minimal effect on cell proliferation and viability.