An intelligent nanoplatform for simultaneously controlled chemo-, photothermal, and photodynamic therapies mediated by a single NIR light

Combination therapy involves the design of one unit with various therapeutic effects, such as simultaneous photothermal therapy (PTT), chemotherapy and photodynamic therapy (PDT), to produce high therapeutic efficacy with minimized side effects. Here, we designed a single near-infrared (NIR) light induced tri-mode (PTT, PDT and chemotherapy) combined therapeutic nanoplatform (named IONCs@Ce6-DOX/PCM) based on amine-functionalized iron oxide nanocrystals (IONCs). The IONCs, were subsequently loaded with the photosensitizer chlorin e6 (Ce6), doxorubicin (DOX) and a layer of tetradecanol (PCM, a temperature sensitive phase-change material used as a smart switch for drug release). In this system, the IONCs generate heat for PTT and melt the coated PCM when irradiated by a 650 nm laser with a low power density (230 mW/cm(2)), resulting in the release of encapsulated DOX. Simultaneously, the exposed Ce6 can also generate cytotoxic reactive oxygen species (ROS) under the same NIR light irradiation, thereby achieving combined therapy triggered by a single light. Moreover, taking advantage of the magnetic property of IONCs, the nanoplatform could also be developed as a biocompatible diagnostic agent for magnetic resonance (MR) imaging. This, indicates that the multifunctional carriers can facilitate a range of imaging guided cancer treatments and provide synergistic photothermal/chemo/photodynamic therapy for improved treatment efficiency and minimized side effects.