Prodrugs represent the compounds that can convert to the bioactive drugs under in vitro or in vivo environment after administration, which have received intensive and extensive attention in the past decades. Among them, several of clinical successes have been achieved, disclosing the promising future of prodrugs. As compared with the conventional nanoscaled drug delivery system, prodrug provides the merits of the high and constant drug efficiency, high stability in blood circulation and low burst release. Nonetheless, critical challenges remain in the development of prodrugs aiming at clinical benefit, mainly including the inability of controlled and targeted drug release. Prodrugs that can selectively release the carried drug specific to microenvironment of lesion site emerges as a powerful strategy to address the above issues. These prodrugs are structurally polymeric and the mechanism of the design is generally based on the physical (pH, temperature) or biological (enzyme, glutathione concentration) stimulus. Herein, we present an overview of the recent work on stimuli-responsive anticancer polymeric prodrugs, including pH-sensitive, redox sensitive and enzyme digestion, based on the domestic and international research progress. In addition, recent advances and future directions in the development of stimuli-responsive and polymeric prodrugs are also included. Contents
1 Introduction
2 Stimuli-responsive polymeric prodrugs
2.1 pH-sensitive polymeric prodrugs
2.2 Temperature-sensitive polymeric prodrugs
2.3 Redox-sensitive polymeric prodrugs
2.4 Enzyme-sensitive polymeric prodrugs
2.5 Other polymeric prodrugs
3 Conclusion and outlook