Folate-conjugated thermoresponsive star-shaped amphiphilic block copolymers for efficient intracellular release of anticancer drugs

The multifunctional polymeric micelle-based carriers possess several unique features, such as improving the aqueous solubility of lipophilic drugs, prolonging the circulation time,stabilizing and protecting drugs that are sensitive to surrounding environment, reducing nonspecific uptake by thereticuloendothelial system (RES) and facilitating targeted drugdelivery. However, the effective concentration of active antitumor drug is often insufficient within cancer cells due tothe premature and none site-specific drug release from polymeric micelles. The quick intracellular drug release isdesirable after the micelles uptake by cancer cells, which may enhance the anticancer efficacy as well as reducing drug resistance in cancer cells [1-3].