目的 合成还原敏感型透明质酸-熊果酸聚合物（hyaluronic acid-cystamine-ursolic acid，HSU）和非还原敏感型透明质酸-熊果酸聚合物（hyaluronic acid-ursolic acid，HU），包载紫杉醇制备成聚合物胶束（PTX-HSU和PTX-HU），对二者的逆转肿瘤多药耐药性进行研究。方法 通过傅里叶变换红外光谱（Fourier transform infrared spectroscopy，FT-IR）、氢核磁共振波谱（hydrogen nuclear magnetic resonance spectroscopy，H¹-NMR）法对HSU和HU进行表征；通过差示扫描量热（differential scanning calorimetry，DSC）和X射线衍射（X-ray diffraction，XRD）法对PTX-HSU进行物相鉴定；通过体外释放实验考察PTX-HSU和PTX-HU的体外释放行为；选择人乳腺癌细胞MCF-7和人乳腺癌紫杉醇耐药细胞株MCF-7/ADR细胞为细胞模型，通过噻唑蓝比色法（MTT）实验、细胞摄取实验以及胞内谷胱甘肽（glutathione，GSH）测定实验，对HSU逆转肿瘤多药耐药（multidrug resistance，MDR）进行研究。结果 通过FT-IR、H¹-NMR表征证明了HSU和HU的成功合成；DSC、XRD图谱说明紫杉醇以分子状态或无定形存在于HSU胶束骨架中；体外释药实验中PTX-HSU在3 h内快速释放高达80%的紫杉醇，展现出还原响应快速释药性能；MTT实验表明载药胶束均呈现浓度依赖性的细胞毒性，其中PTX-HSU呈现出一定的MDR逆转效果；细胞摄取实验表明MCF-7/ADR对HSU展现出更多的摄取量，胞内GSH测定实验表明HSU降低了MCF-7/ADR细胞内的GSH表达水平（P<0.001）。结论 PTX-HSU作为还原敏感型聚合物胶束可通过增加细胞摄取量、下调胞内GSH表达水平以实现逆转MCF-7/ADR细胞的多药耐药性。

Objective To synthesize reduction-sensitive hyaluronic acid-cystamine-ursolic acid (HSU) and non-reduction-sensitive hyaluronic acid-ursolic acid (HU), prepare paclitaxel-loaded polymeric micelles (PTX-HSU and PTX-HU), investigate the reversal effect on tumor multidrug resistance (MDR) of the polymeric micelles. Methods HSU and HU were characterized by Fourier transform infrared spectroscopy (FT-IR) and hydrogen nuclear magnetic resonance spectroscopy (H¹-NMR). The phase identification of PTX-HSU was carried out by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The in vitro release behavior of PTX-HSU and PTX-HU was investigated by in vitro release assay. Human breast cancer cell MCF-7 and human breast cancer paclitaxel resistant cell line MCF-7/ADR were selected as cell models, and thiazole blue colorimetry (MTT) assay, cell uptake assay and intracellular glutathione (GSH) assay were performed to investigate the reversal effect of multidrug resistance in HSU. Results The synthesis of HSU and HU was verified by FT-IR and H¹-NMR. DSC and XRD patterns indicated that paclitaxel existed in the HSU micelle skeleton in the molecular state or amorphous form. It was observed that more than 80% of paclitaxel in PTX-HSU was released during three hours in the assay of drug release in vitro, which showed a reductive-responsive rapid drug release behavior. The drug-loaded polymeric micelles showed concentration-dependent cytotoxicity by the MTT assay, and PTX-HSU showed a certain reversal effect of MDR. The cellular uptake of PTX-HSU in vitro was examined in MCF-7/ADR cells by flow cytometry, which assay demonstrated that MCF-7/ADR exhibited increased uptake of HSU. The intracellular GSH assay showed that HSU decreased the expression of GSH in MCF-7/ADR cells (P < 0.001). Conclusion As a reduction-sensitive polymeric micelle, PTX-HSU can be used to reverse multidrug resistance in MCF-7/ADR cells by increasing cellular uptake and down-regulating intracellular GSH expression.

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福建省科技厅引导性项目（2020Y0051）；福建中医药大学校管科研平台专项资助项目（X2018002-重点）；福建省中药学重点实验室开放课题资助项目（X2018005）