In this study, D-alpha-tocopheryl polyethylene glycol-1000 succinate (TPGS)-coated docetaxel-loaded liposomes were developed to reverse multidrug resistance (MDR) and enhance lung cancer therapy. Evaluations were performed using human lung cancer A549 and resistant A549/DDP cells. The reversal multidrug resistant effect was assessed by P-gp inhibition assay, cytotoxicity, cellular uptake, and apoptosis assay. The tumor xenograft model was built by subcutaneous injection of A549/DDP cells in the right dorsal area of nude mice. The tumor volumes and body weights were measured every other day. The TPGS-coated liposomes showed a concentration- and time-dependent cytotoxicity and significantly enhanced the cytotoxicity of docetaxel in A549/DDP cells. Confocal laser scanning images indicated that higher concentrations of coumarin-6 were successfully delivered into the cytoplasm, and the TPGS-coated liposomes enhanced intracellular drug accumulation by inhibiting overexpressed P-glycoprotein. The TPGS-coated liposomes were shown to induce apoptosis. Furthermore, in vivo anti-tumor studies revealed that TPGS-coated docetaxel-loaded liposomes had outstanding anti-tumor efficacy in an A549/DDP xenograft model. The TPGS-coated liposomes, compared with PEG-coated liposomes, showed significant advantages in vitro and in vivo. The TPGS-coated liposomes were able to reverse MDR and enhance lung cancer therapy. Graphical abstract .
Keywords: Docetaxel; Liposomes; Lung cancer; Multidrug resistance; TPGS.