A stimuli-responsive drug delivery system based on konjac glucomannan, carboxymethyl chitosan and mesoporous polydopamine nanoparticles.

A stimuli-responsive drug delivery system is developed for controlled delivery of curcumin (Cur) and chemo-photothermal therapy of breast cancer (BC). Cur is first loaded into mesoporous polydopamine nanoparticles (mPDA NPs) by π-π stacking, and then the Cur loaded mPDA NPs (mPDA NPs@Cur) are encapsulated in the hydrogels prepared through the crosslinking of oxidized konjac glucomannan (oxKGM) and carboxymethyl chitosan (CMCS). Owing to the pH-sensitivity of the hydrogels and the outstanding photothermal conversion capability of mPDA NPs, the release of Cur from the hydrogels can be greatly accelerated in acidic media upon near infrared (NIR) irradiation. Cytotoxicity assay indicates that the hydrogels have significant cytotoxicity against murine breast tumor cell 4 T1 while the drug-free hydrogels (oxKGM/CMCS/mPDA NPs) show good biocompatibility. In addition, the hyperthermia generated upon NIR irradiation can lead to the apoptosis of cancer cells, achieving chemo-photothermal combination therapy of BC. Release kinetics study reveals that the release of Cur from the hydrogels follows zero-order model.