Indomethacin-grafted and pH-sensitive dextran micelles for overcoming inflammation-mediated multidrug resistance in breast cancer.

•IND-grafted dextran micelles by acetal linkage with loading DOX overcomed tumor MDR.•These micelles showed an accelerated drug release at acid tumor environments.•IND efficiently increased intracellular DOX concentration by reducing MPR1 levels.•IND could remove apoptosis-resistance by down-regulating bcl-2/bax rate.•These particles possessed higher antitumor effect and excellent biosafety.