Biotin-modified acid-sensitive micelles for enhancing antitumor effect of paclitaxel

This study was aimed at fabricating tumor targeting and acid-responsive micelles as carriers for paclitaxel (PTX). An amphipathic polymer TOS-Ace-PEG-Bio was designed and synthesized by conjugating α-tocopherol succinate (TOS) with biotinylated polyethylene glycol (PEG-Bio) via acetal bond. The polymer could self-assemble into nanosized micelles and encapsulate PTX. The PTX-loaded micelles possessed appropriate particle size with the mean value of 129.3 ± 0.9  nm . Strong pH dependent PTX release behavior was verified by in vitro drug release study. At cellular level, the PTX-loaded micelles could be selectively internalized by MCF-7 cells. The in vivo study also confirmed their excellent antitumor activity and reduced side effects. Based on these features, the TOS-Ace-PEG-Bio micelles were considered to be promising carriers for delivery of PTX.