Encapsulated paclitaxel nanoparticles exhibit enhanced anti-tumor efficacy in A549 non-small lung cancer cells

In the present study, paclitaxel （PTX） were encapsulated with polyethylene glycol （PEG）-polylactide （PLA）/D-（~ tocopheryl polyethylene glycol 1000 succinate （TPGS） （PEG-PLA/TPGS） and the enhanced anti-tumor activity of this PTX mixed micelles （PTX-MM） was evaluated in lung cancer cells. The PTX- MM prepared by a solvent evaporation method was demonstrated to have high drug-loading effi- ciency （23.2%）, high encapsulation efficiency （76.4%）, and small size （59 nm）. In vitro release assay showed the slow release behavior of PTX-MM, suggesting the good stability of the PTX-MM essential for long circulation time. In vitro kinetics assay demonstrated that PTX-MM could promote absorption and increase relative bioavailability. The anti-cancer efficiency of PTX-MM was also examined by both in vitro and in vivo studies. PTX-MM exhibits obvious cytotoxicity against lung cancer cells with much lower IC50 value when compared with commercial formulated PTX or PTX ＋TPGS. The xenograft tumor model studies on nude mice indicated that PTX-MM inhibits tumor growth more effectively than other formulations. It was also found that most of mixed micelles were integral in tumor site to exhibit anti-cancer activity. Our results suggested that the use of PTX-MM as an anti-cancer drug may be an effective approach to treat lung cancer.