A smart upconversion-based light-triggered polymer for synergetic chemo-photodynamic therapy and dual-modal MR/UCL imaging

We have developed a novel nanocomposite to achieve effective therapy and live surveillance of tumor tissue. In this study, fullerene ( C60) with iron oxide ( Fe3O4) nanoparticles and upconversion nanophosphors ( UCNPs) was loaded into N-succinyl-N'-4-(2-nitrobenzyloxy)succinyl-chitosan micelles ( SNSC) with good biocompatibility. In addition, hydrophobic anticancer drug docetaxel ( DTX) was also loaded into the nanocomposites. The experiments conducted in vitro and in vivo demonstrated that C-60/Fe3O4-UCNPs@DTX@SNSC can act synergistically to kill tumor cells by releasing chemotherapy drugs at specific target site as well as generating reactive oxygen using 980 nm. In addition, it can also be used for non-invasive deep magnetic resonance and upconversion fluorescence dual-mode imaging. The results indicated that this system provided an efficient method to surmount the drawback of UV or visible light-responsive polymeric systems for controlled drug release and generated reactive oxygen in deep tissues and ultimately realized the integration of dual-modal imaging and treatment. (C) 2016 Elsevier Inc. All rights reserved.