A TPGS-incorporating nanoemulsion of paclitaxel circumvents drug resistance in breast cancer

Paclitaxel resistance is usually developed in clinical chemotherapy, which remains a major obstacle for successful cancer treatment. Herein, we attempted to develop a TPGS incorporating nanoemulsion of paclitaxel (NE-PTX) to circumvent the drug resistance in breast cancer. NE-PTX was prepared by a self-assembly technique and the physicochemical properties were characterized. The efficacy of NE-PTX on overcoming paclitaxel resistance was measured by in vitro and in vivo evaluation. The measured results indicated that NE-PTX was nanometer-sized droplets with the mean diameter of 24.93 +/- 3.45 nm. The IC50 value of paclitaxel in resistant MCF-7/ADR cells was greatly reduced from 101.45 mg/mL to 5.39 mg/mL, which indicated that the paclitaxel resistance was effectively reduced by NE-PTX. The reversal of paclitaxel resistance could mainly ascribe to the significant inhibition of P-gp activity and enhancement of anti-cancer activity. Moreover, the tumor volume in resistant tumor xenograft model treated with NE-PTX was only 10.06% of that of paclitaxel solution group, and the tumor inhibitory rate of NE-PTX reached 93.84%, which effectively verified the efficacy of NE-PTX on treating paclitaxel resistance. Thereby, NE-PTX could provide an effective strategy for circumventing paclitaxel resistance in breast cancer. (C) 2014 Elsevier B. V. All rights reserved.