pH- and β-cyclodextrin-responsive micelles based on polyaspartamide derivatives as drug carrier

A novel kind of graft polymer poly(aspartic acid)-ethanediamine-g-adamantane/methyloxy polyethylene glycol (Pasp-EDA-g-Ad/mPEG) was designed and synthesized for drug delivery in this study. The chemical structure of the prepared polymer was confirmed by proton NMR. The obtained polymer can self-assemble into micelles which were stable under a physiological environment and displayed pH- and β-cyclodextrin (β-CD)-responsive behaviors because of the acid-labile benzoic imine linkage and hydrophobic adamantine groups in the side chains of the polymer. The doxorubicin (Dox)-loaded micelles showed a slow release under physiological conditions and a rapid release after exposure to weakly acidic or β-CD environment. The in vitro cytotoxicity results suggested that the polymer was good at biocompatibility and could remain Dox biologically active. Hence, the Pasp-EDA-g-Ad/mPEG micelles may be applied as promising controlled drug delivery system for hydrophobic antitumor drugs. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1387–1395