In vitro degradability and stability of hydrophobically modified pH‐sensitive micelles using MPEG‐grafted poly(β‐amino ester) for efficient encapsulation of paclitaxel

Abstract

Methoxypoly(ethylene glycol)‐grafted poly(β‐amino ester) was synthesized for the fabrication of pH‐sensitive micelles, and these micelles were modified with deoxycholic acid to facilitate the hydrophobic interaction between the micellar core and paclitaxel. The micelle properties were studied by dynamic light scattering and fluorescence spectrometry. An in vitro degradation study showed that the synthesized polymers degraded hydrolytically within 24 h under physiological conditions. The stability of paclitaxel‐loaded pH‐sensitive micelles was evaluated in vitro. The introduced deoxycholic acid more stabilized the micelles at pH 7.4 compared to the micelles without modification. But the pH‐sensitive region of the micelles was lowered from pH 6.8 to pH 5.8. These results indicate that pH‐sensitive micelles with improved stability have great potential as hydrophobic drug carriers for tumor targeting. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010