Cancer-specific DDS using stimuli-responsive polymers

Cancer chemotherapy has a serious difficulty with its poor cell specificity. DDS using nano-medicine consisting of polymer materials will be one of the most promising strategies to address this issue. Almost all cancer nano-medicines uses enhanced permeability and retention effect (EPR effect) based on extravasation of huge molecules in tumor neovasculature. As an additional effect, cancer specific ligand-receptor interaction is also available to enhance the binding ability of nano-medicine to cancer cells. Although these strategies realize significant drug accumulation in tumors compared with small drug administration, greater amount of nanomedicine may still be distributed to other non-target organs. In this context, Stimuli-responsive polymers have been applied to enhance the contrast of drug concentration between tumor and normal cells. In this review, recent progress of cancer DDS materials using a stimuli-responsive strategy is reviewed. Future directions for ideal cancer nanomedicine is also considered.