紫杉醇还原敏感型聚合物胶束的制备及其逆转肿瘤多药耐药的研究

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...

Preparation of paclitaxel-loaded reduction-sensitive polymer micelles and their reversal effect on multidrug resistance in tumor

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.