Redox-responsive AIE micelles for intracellular paclitaxel delivery

Compared with conventional drug nanocarriers, multifunctional drug delivery systems exhibited characteristic advantages. In this study, we developed a multifunctional drug delivery system possessing stimuli-responsive drug release and cellular imaging. Amphiphilic polymers, methoxypolyethylene glycol-cystamine-tetraphenylethene (mPEG 1k -SS-TPE), were synthesized by combining methoxypolyethylene glycol (mPEG 1k ) and tetraphenylethene (TPE) using reduction-sensitive disulfide bonds that can be disconnected by high level of inherent glutathione (GSH). Size distribution and morphology of mPEG 1k -SS-TPE micelles were evaluated. Meanwhile, the reduction-sensitivity of mPEG 1k -SS-TPE micelles was surveyed compared with that of mPEG 1k -TPE micelles. Nile Red was encapsulated into mPEG 1k -SS-TPE micelles to visually observe intracellular drug delivery against SW480 cells. Paclitaxel (PTX) was chosen to be loaded into micelles to evaluate the cytotoxicity against HCT116, HT-29, and SW480. Graphical Abstract