2-脱氧-D-葡萄糖标记的氧化铁纳米粒对乳腺癌细胞和正常细胞靶向性的比较

Comparison of the targeting properties of 2-deoxy-D-glucose-conjugated nanoparticles to breast cancer MDA-MB-231 cells and breast fibroblasts

目的比较2-脱氧-D-葡萄糖（2-DG）标记的氧化铁纳米粒（y-Fe2O，@DMSA．DGNPs）对高代谢乳腺癌细胞（MDA-MB-231）和正常代谢乳腺成纤维母细胞（HUM，CELL-0056）的靶向吸收差异，探讨其作为磁共振成像（MRI）对比剂靶向高代谢肿瘤的可行性。方法制备1．Fe2O3@DMSA．DGNPs纳米粒，采用葡萄糖氧化酶法测定细胞的代谢水平，采用普鲁士蓝染色法和比色法检测MDA-MB-231和HUM—CELL-0056细胞分别与1-Fe2O3@DMSA—DGNPs和二巯基丁二酸修饰的^y-Fe2O3纳米粒（-y—Fe2O3@DMSANPs）孵育10min、30min、1h和2h后的靶向性吸收情况，MRI观察T2WI信号强度变化。结果普鲁士蓝染色显示，MDA—MB-231细胞与y-Fe2O3@DMSA．DGNPs孵育后蓝染颗粒较多，有大量铁存在；而与y-Fe2O3@DMSANPs孵育后蓝染颗粒较少，显示铁含量较低；与y-Fe2O3，@DMSA—DGNPs＋D-葡萄糖孵育后蓝染颗粒极低，铁含量明显减少。比色法检测显示，MDA—MB-231细胞对_y-Fe2O3@DMSA-DGNPs的吸收量明显大于对y-Fe2O3@DMSANPs和y-Fe2O3@DMSA-DGNPs＋D．葡萄糖的吸收量，差异有统计学意义（P〈0．05）。纳米粒的吸收呈时间依赖性。MRI检测结果显示，MDA—MB-231细胞y-Fe2O3@DMSA-DGNPs组T2WI信号强度降低明显，在孵育10min、30min、1h和2h时，信号变化率的中位数分别为10．5％、37．5％、72．9％和92．0％；而1一Fe203@DMSANPs组的T2WI信号强度降低相对较小，在孵育10min、30min、1h、2h时，信号变化率的中位数分别为8．5％、11．4％、32．0％和76．7％。HUM—CELL-0056细胞对1-Fe203@DMSA-DGNPs、y-Fe2O3@DMSANPs和1．Fe203@DMSA—DGNPs＋D-葡萄糖吸收不明显，T2WI信号强度变化差异不大。结论y-Fe2O3，@DMSA．DGNPs对高代谢乳腺癌细胞有良好的靶向性，可作为靶向高代谢肿瘤的MRI对比剂进行体内实验。

Objective To compare the differences in uptake of 2-deoxy-D-glucose （2-DG）- conjugated nanoparticles between breast carcinoma MDA-MB-231 cells with high metabolism and breast fibroblasts with normal metabolism, and investigate the feasibility of using the coated nanopartieles as a MRI- targeted contrast agent for highly metabolic carcinoma cells. Methods The y-Fe2O3 @ DMSA-DG was prepared. The glucose metabolism level of both cell lines was determined. The targeting efficacy of y-Fe2O3 @ DMSA-DG andy-Fe2O3@ DMSA NPs to breast carcinoma MDA-MB-231 cells and breast fibroblasts at 10 min, 30 min, 1 h and 2 h was measured with Prussian blue staining and UV colorimetrie assay. MRI was performed to visualize the changes of T2WI signal intensity. Results Prussian blue staining showed more intracelhilar blue granules in the MDA-MB-231 cells of y-Fe2O3 @ DMSA-DG NPs group than that in the y-Fe2O3@ DMSA NPs group, and the y-Fe2O3@ DMSA-DG uptake was greatly competed by free D-glucose. As revealed by UV colorimetric assay, MDA-MB-231 cells also showed that the cellular iron amount ofy-Fe2O3@ DMSA-DG group was significantly higher than that of the y-Fe2O3@ DMSA group and y-Fe2O3@ DMSA-DG ＋ D-glucose group, statistically with a significant difference between them. MRI showed that the signal intensity of y-Fe2O3 @ DMSA-DG group was decrease significantly, the T2 signal intensity was decreased by 10.5% , 37.5%, 72.9% , 92.0% for 10 min, 30 min, 1 h and 2 h, respectively. In contrast, the signal intensity did not show obvious decrease in the y-Fe2O3 @ DMSA-DG group, the T2 signal intensity was decreased by 8.5% , 11.4% , 32.0%, 76.7% for 10 rain, 30 min, 1 h and 2 h, respectively. However, HUM-CELL-O056 cells did not produce apparent difference for positive staining in the y-Fe2O3@ DMSA-DG group, y-Fe2O3 @ DMSA group and y-Fe2O3 @ DMSA-DG ＋ D-glucose group, and the signal intensity also did not produce apparent difference. Conclusions y-Fe2O3@ DMSA-DG has good targeting ability to highly metabolic breast carcinoma （MDA-MB-231） cells. It is feasible to serve as a specific MRI- targeted contrast agent for highly metabolic carcinoma cells, and deserves further studies in vivo.