Objective. To prepare a polyethylene glycol- (PEG-) modified rare earth metal-organic framework material drug delivery system, obtain DOX@Eu (BTC) fluorescent nanoparticles after loading doxorubicin (DOX), and explore the effect of DOX@Eu (BTC) fluorescent nanoparticles on the chemotherapy sensitivity of gastric cancer multidrug-resistant cells SGC7901/ADR. Methods. The rare earth metal-organic framework fluorescent nanoparticles EU (BTC) were prepared by the solvent method and modified with PEG, and DOX@Eu (BTC) fluorescent nanoparticles were obtained after loading DOX. The particle size distribution of the prepared nanoparticles was analyzed by TEM, the adsorption performance of the prepared nanoparticles was evaluated by BET, the effective drug loading of DOX in the nanoparticles was determined by TGA analysis, and the pH response release performance was evaluated by in vitro release experiments. The MTT method was used to test the toxicity of EU (BTC) to GES-1 and SGC7901/ADR cells and detect the proliferation of SGC7901/ADR cells in each group. A fluorescence confocal microscope was used to observe the positioning of DOX@Eu (BTC) in SGC7901/ADR cells. The expression level of miR-185 in each group of cells was detected by RT-qPCR. The Annexin V-FITC/PI method was used to determine the apoptosis rate of cells in each group. The expression of MRS2 and related drug resistance proteins in each group of cells was detected by Western blotting (WB). The dual-luciferase reporter gene experiment was used to verify the targeting relationship between miR-185 and MRS2. Results. Most of the prepared EU (BTC) fluorescent nanoparticles have a particle size between 50 and 200 nm and have good adsorption capacity. The effective drug loading of DOX is 29%, and it has pH-responsive release performance and can be used in acidic environments. DOX was immobilized in EU (BTC) fluorescent nanoparticles, and DOX@Eu (BTC) fluorescent nanoparticles were present in the cytoplasm or cell membrane of SGC7901/ADR cells. Compared with DOX, DOX@Eu (BTC) fluorescent nanoparticles have stronger cytotoxicity to SGC7901/ADR cells, which also effectively inhibited the expression of multidrug resistance proteins in cells. The expression level of miR-185 in SGC7901/ADR cells decreased, but the expression level of MRS2 protein in SGC7901/ADR cells increased. miR-185 and MRS2 proteins are closely related to the multidrug resistance of SGC7901/ADR cells, and MRS2 is the downstream target gene of miR-185. After the treating of SGC7901/ADR cells with DOX@Eu (BTC) fluorescent nanoparticles, the expression of miR-185 in the cells increased significantly, while the expression of MRS2 protein decreased significantly, and the magnitude of the change was more obvious than that of DOX treatment. Overexpression of miR-185 (miR-mimics) or inhibition of MRS2 (si-MRS2) enhanced the inhibitory effect of DOX@Eu (BTC) fluorescent nanoparticles on the proliferation of SGC7901/ADR cells, which significantly increased the induction of apoptosis by DOX@Eu (BTC) fluorescent nanoparticles, and simultaneous enhanced the inhibitory effect on the expression level of multidrug resistance protein. However, overexpression of miR-185 and MRS2 (pc-MRS2+miR-mimics) at the same time did not affect the chemotherapy sensitivity of SGC7901/ADR cells to DOX@Eu (BTC) fluorescent nanoparticles. However, simultaneous transfection of miR-185 mimics and pc-MRS2 did not affect the chemotherapy sensitivity of SGC7901/ADR cells to DOX@Eu (BTC) fluorescent nanoparticles. Conclusion. DOX@Eu (BTC) fluorescent nanoparticles can effectively enhance the chemotherapy sensitivity of SGC7901/ADR cells to DOX, which may be achieved by upregulating the expression of miR-185 in SGC7901/ADR cells and then inhibiting the expression of MRS2 protein.

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以金属有机骨架荧光纳米粒子为载体的盐酸阿霉素对耐药胃癌细胞系的化学治疗作用及机理研究

目标。为了制备聚乙二醇-（PEG-）修饰的稀土金属-有机骨架材料药物传递系统，在装载阿霉素（DOX）后获得DOX @ Eu（BTC）荧光纳米颗粒，并探索DOX @ Eu（BTC）荧光的作用纳米粒对胃癌多药耐药细胞SGC7901 / ADR化疗敏感性的影响。方法。通过溶剂法制备稀土金属-有机骨架荧光纳米粒子EU（BTC）并进行PEG修饰，负载DOX后得到DOX @ Eu（BTC）荧光纳米粒子。通过TEM分析制备的纳米颗粒的粒度分布，通过BET评估制备的纳米颗粒的吸附性能，通过TGA分析确定DOX在纳米颗粒中的有效药物载量，并通过HPLC评估pH响应释放性能。体外发布实验。采用MTT法检测EU（BTC）对GES-1和SGC7901 / ADR细胞的毒性，并检测SGC7901 / ADR细胞的增殖。使用荧光共聚焦显微镜观察DOX @ Eu（BTC）在SGC7901 / ADR细胞中的定位。通过RT-qPCR检测miR-185在每组细胞中的表达水平。用膜联蛋白V-FITC / PI法测定各组细胞的凋亡率。通过Western blotting（WB）检测每组细胞中MRS2和相关耐药蛋白的表达。双荧光素酶报告基因实验用于验证miR-185与MRS2之间的靶向关系。结果。大部分制备的EU（BTC）荧光纳米颗粒的粒径在50到200 nm之间，并具有良好的吸附能力。DOX的有效载药量为29％，具有pH响应释放性能，可用于酸性环境。将DOX固定在EU（BTC）荧光纳米颗粒中，并且SGC7901 / ADR细胞的细胞质或细胞膜中存在DOX @ Eu（BTC）荧光纳米颗粒。与DOX相比，DOX @ Eu（BTC）荧光纳米颗粒对SGC7901 / ADR细胞具有更强的细胞毒性，也有效抑制了细胞中多药耐药蛋白的表达。miR-185在SGC7901 / ADR细胞中的表达水平降低，但MRS2蛋白在SGC7901 / ADR细胞中的表达水平升高。miR-185和MRS2蛋白与SGC7901 / ADR细胞的多药耐药性密切相关，而MRS2是miR-185的下游靶基因。用DOX @ Eu（BTC）荧光纳米颗粒处理SGC7901 / ADR细胞后，miR-185的表达明显增加，而MRS2蛋白的表达则明显减少，变化幅度比DOX处理。miR-185（miR-mimics）的过表达或MRS2（si-MRS2）的抑制增强了DOX @ Eu（BTC）荧光纳米颗粒对SGC7901 / ADR细胞增殖的抑制作用，这大大增加了DOX对细胞凋亡的诱导作用。 @Eu（BTC）荧光纳米颗粒，同时增强了对多药耐药蛋白表达水平的抑制作用。然而，同时过量表达miR-185和MRS2（pc-MRS2 + miR-mimics）不会影响SGC7901 / ADR细胞对DOX @ Eu（BTC）荧光纳米粒子的化学敏感性。但是，同时转染miR-185模拟物和pc-MRS2不会影响SGC7901 / ADR细胞对DOX @ Eu（BTC）荧光纳米粒子的化学敏感性。结论。DOX @ Eu（BTC）荧光纳米粒子可以有效增强SGC7901 / ADR细胞对DOX的化疗敏感性，这可以通过上调SGC7901 / ADR细胞中miR-185的表达然后抑制MRS2蛋白的表达来实现。