MR features of mice spleen lymphocytes labeled with super-paramagnetic iron oxide particles / 中华放射学杂志

ABSTRACT

Objective To investigate the feasibility of labeling mice spleen lymphocytes with superparamagnetic iron oxide(SPIO)and in vitro MR imaging of the labeled cells.Methods Spleen lymphocytes of 5 mice were isolated and then labeled with SPIO of 100,50,25,15,10,5 μg/ml,which was previously prepared with PLL.Prussian blue staining was performed to show the intracellular iron.Cell viability was compared among fresh,labeled and unlabeled cells.Different concentrations of mice spleen lymphocytes were screened using 3.0 T MR on T2WI,T2 * WI and SWI sequences in vitro.Cell viability was compared using independent-sample t test between groups.The MRI values among different groups were compared using one-way ANOVA.Results SPIO prepared with PLL could successfully label mice spleen lymphocytes,the optimum concentration of SPIO was 5 μg/ml.The Prussian blue staining showed intracellular blue spots and a labeling efficiency of(93.6 ± 2.1)％.Three groups of fresh,labeled and unlabeled cells showed a Trypan blue staining result of(94.8 ± 3.1)％,(88.7 ± 2.7)％,and(88.9 ±3.2)％,respectively; no statistically significant difference was found in cell viability between labeled and unlabeled lymphocytes(t =0.281,P ＞ 0.05); however,the cell viability of fresh cells were statistically significant higher than the labeled and unlabeled lymphocytes(t =8.125 and 7.253 respectively,P ＜0.05for all).Among the T2 WI,T2 * WI and SWI sequences under the same concentrations of cells,the SWI sequence was the most sensitive.Conclusions The mice spleen lymphocytes can be effectively labeled with SPIO with no impact on cell viability,and MR can be used to track these labeled cells in vitro.The SWI sequence is the most sensitive.