目的 利用叶酸受体(folate receptor,FR)阳性的Bel7402人肝癌细胞及磁共振成像系统来探讨超顺磁性氧化铁-多巴胺-葡聚糖-叶酸(NP-DA-Dextra-FA)靶向纳米复合物的细胞靶向性并监测其体外成像的可行性.材料与方法 研制叶酸靶向纳米分子探针(NP-DA-Dextra-FA)及非靶向纳米分子探针(NP-DA-Dextran).将人肝癌细胞Bel7402与叶酸靶向纳米分子探针及非靶向探针分别孵育2 h后,行普鲁士蓝染色实验及细胞MR成像扫描,分析其T2WI信号强度及信号强度变化率的改变,并行竞争抑制实验.结果 不同Fe浓度NP-DA-Dextra-FA及NP-DA-Dextran纳米分子探针分别与Bel7402细胞孵育后,靶向分子探针组结果显示Bel7402细胞T2信号强度随着铁浓度的升高明显减低,普鲁士蓝染色实验表明大量蓝色铁颗粒沉积位于Bel7402细胞内;非靶向组结果表明Bel7402细胞信号强度减低相对不明显,普鲁士蓝染色示Bel7402细胞内仅见少量蓝色铁颗粒沉积.竞争抑制实验结果表明随着叶酸浓度的升高,T2信号强度逐渐升高.结论 叶酸靶向磁性纳米分子探针对人肝癌细胞Bel7402有靶向性,体外磁共振成像可对其靶向性监测.%Objective: To observe the targeting function of folate-conjugated superparamagnetic iron oxide-dopamine (NP-DA-Dextra-FA) to Bel7402 cells by folate receptor (FR) and the possibility for monitoring tumor targeting with MRI. Materials and Methods: NP-DA-Dextra-FA and NP-DA-Dextran were hatched with Bel7402 cells for 2 h, separately. Prussian blue staining was used to survey intracellular irons, meanwhile MRI was used to research the signal intensity of cells. The competitive inhibition test was performed. Results: The experimental group showed the T2WI signal intensity of Bel7402 cells declined significantly with the rise of NP-DA-Dextra-FA's iron concentration. A lot of intracellular irons were observed in Bel7402 cells. The control group showed the signal intensity of Bel7402 cells on T2WI decreased less clearly. Some intracellular irons were showed in Bel7402 cells. The competitive inhibition test showed the T2WI signal intensity increased with the folic acid concentration rising. Conclusion: In vitro, the NP-DA-Dextra-FA has obvious targeting ability to Bel7402 cells. The cell targeting processes could be supervised with MRI.
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