Cancer is still considered to be one of the most severe diseases so far. Multidrug resistance (MDR) is a major obstacle against
curative cancer chemotherapy. The over-expression of drug efflux pumps in cellular membrane plays a critical role in preventing cancer
cells from conventional chemotherapy. Nanotechnology is emerging as a class of therapeutics for MDR. This review mainly focuses on
some pivotal strategies to combat MDR, including the enhanced permeability and retention (EPR) effect, stealth nanoparticles to prolong
circulation time, endosomal escape, active drug delivery, stimuli sensitive drug release, and targeted co-delivery of different compounds.
While convinced challenges need combatting, large numbers of preclinical studies strongly suggest that nanomedicine formations have
potential application for improving the treatment of MDR.