Mitochondria-Responsive Drug Release along with Heat Shock Mediated by Multifunctional Glycolipid Micelles for Precise Cancer Chemo-Phototherapy.

Responsive drug release in tumor mitochondria is a pre-requisite for mitochondria-targeted drug delivery systems to improve the efficacy of this promising therapeutic modality. To this end, a photothermal stimulation strategy for mitochondria-responsive drug release along with heat shock is developed to maximize the antitumor effects with minimal side effects. This strategy relies on mitochondrial-targeted delivery of doxorubicin (DOX) through a photothermal and lipophilic agent IR-780 iodide (IR780)-modified glycolipid conjugates (CSOSA), which can synergistically triggers high-level reactive oxygen species (ROS) to kill tumor cells. Specifically, upon laser irradiation, the photothermal conversion by IR780-CSOSA can not only weaken the hydrophobic interaction between the core of micelles and DOX and trigger unexpected micelle swelling to release DOX in mitochondria for the amplification of ROS, but also induce mitochondria-specific heat shock to promote the fast evolution of ROS at the same locus to eradicate cancer cells in a more effective way. Furthermore, IR780-CSOSA micelles may independently realize the real-time diagnosis and imaging on multiple tumor models. Deep penetration into tumors by IR780-CSOSA/DOX micelles can be manipulated under laser irradiation. Such multifunctional IR780-CSOSA/DOX micelles with integration of mitochondria-responsive drug release and heat shock are demonstrated to be superior to the non-mitochondria-responsive therapy. This study opens up new avenues for the future cancer diagnosis and treatment.