Development of nanocarriers functionalized with stimuli-responsive polymer for controlled cellular uptake

Drug delivery system (DDS) is a technology that controls sustained release of medicines in the body and localized delivery to diseased tissues. Therefore, it is possible to keep the concentration of medicine at therapeutically effective concentrations for a long time and to reduce side effects. We have achieved controlled intracellular uptake, and release of medicines by nanocarriers modified with stimuli-responsive polymers based on poly(N-isopropylacrylamide), which undergoes a reversible phase transition in response to external temperature stimulation. In this article, we introduce our recent research on the design of temperature- and pH-responsive polymers, which enables selective intracellular uptake with external stimulation, and applications to DDS of an anti-tumor agent and siRNA by micelle and liposomes modified with those polymers.