声诺维超声辐照改善超顺磁性氧化铁纳米粒子对肝癌细胞Hep-G2体外标记效果

SonoVue-enhanced ultrasound exposure(SEUE) improves the SPIO-labeling efficiency in Hep-G2 cells in vitro

目的探讨声诺维超声辐照改善体外超顺磁性氧化铁纳米粒子(SPIO)对肝癌细胞Hep-G2标记效果的可行性。方法 7组不同浓度的SPIO在体外与Hep-G2细胞混合,在加入声诺维后采用超声处理1 min,然后监测细胞标记效率、细胞活性和增殖能力。挑选标记效果好,且增殖能力影像小的375μg[Fe]/mL SPIO浓度组,分别以细胞密度为1×102,1×103,1×104,1×105,1×106,及1×107(个细胞/mL),用临床1.5T磁共振进行扫描。结果实验组中所有7个亚组的标记率都超过90%,两组对照组标记率约为2%。Hep-G2细胞活率随SPIO浓度增加而减低,其在500μg[Fe]/mL、625μg[Fe]/mL、750μg[Fe]/mL和875μg[Fe]/mL的活率分别为59.7%±7%、47.76%±9%、46.27%±10%和43.28%±7%,提示当SPIO浓度达到或大于500μg[Fe]/mL时对HepG2细胞具有明显毒性,但其增殖活性并无明显差异。体外磁共振扫描结果显示T2W1序列信号减低,能敏感显示SPIO浓度的变化;其信号强度与细胞浓度呈负相关(P<0.05)。结论声诺维超声辐照确实能改善体外SPIO对肝癌细胞Hep-G2的标记效率,MRI可切实、敏感地对其进行检测。

Objective To investigate the feasibility of using SonoVue-enhanced ultrasound exposure （SEUE） to improve the efficiency of SPIO-labeling Hep-G2 cells in vitro. Methods Seven groups of SPIO at different concentration were incubated with Hep-G2 cells, then processed by SonoVue-enhanced ultrasound exposure （SEUE） for 1 minute. The labeling efficiency, viability and proliferation were examined. The group of 375 μg[Fe]/mL SPIO-labeled Hep-G2 ceils which achieved an appropriate level of proliferative activity at cellular densities （cells/mL） of 1×10^2,1×10^3,1×10^4,1×10^5,1×10^6 and 1×10^7 were processed by an in vitro MRI scan using a clinical 1.ST MR/system. Results A labeling efficiency 〉90% was achieved in seven experimental subgroups of group A, but they were about 2% in control group B and C. Hep-G2 cells was demonstrated reduced viability as the SPIO concentration increased. The viability of cells in four groups was only 59.7%＋7% （500 μg[Fe]/ mL）, 47.76%±9% （625μg[Fe]/mL）, 46.27%±10% （750 μg[Fe]/mL）, and 43.28%±7% （875 μg[Fe]/mL） respectively, which suggests that an SPIO concentration equal to or greater than 500μg [Fe]/mL is obviously toxic to Hep-G2 cells. The proliferation of SPIO-labeled cells did not differ significantly. The in vitro MR/ scanning data showed that the MR/ signal intensity of labeled cells decreased with the T2W1 sequences which represents MRI can sensitively detect the SPIO concentration changes in cells. There was an inverse correlation between the labeling cell population and the signal intensity （P〈0.05）. Conclusions SonoVue-enhanced ultrasound exposure for improving the labeling of Hep-G2 cells with SPIO in vitro is feasible and effective method for MRI scanning.