An O2 Self‐Supplementing and Reactive‐Oxygen‐Species‐Circulating Amplified Nanoplatform via H2O/H2O2 Splitting for Tumor Imaging and Photodynamic Therapy

• Published in: Advanced functional materials Vol. 27; no. 43
• Main Authors: Zhang, Chi, Chen, Wei‐Hai, Liu, Li‐Han, Qiu, Wen‐Xiu, Yu, Wu‐Yang, Zhang, Xian‐Zheng
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 17.11.2017
• Subjects: Biocompatibility; Decomposition; Hydrogen peroxide; Hydroxyl radicals; hypoxic tumors; Infrared radiation; Magnetic resonance imaging; Manganese dioxide; Materials science; Nanocomposites; Nanostructure; Penetration depth; Photodynamic therapy; reactive oxygen species; Singlet oxygen; Titanium oxides; Upconversion; upconversion nanoparticles; Water splitting
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201700626

Conventional photodynamic therapy (PDT) has limited applications in clinical cancer therapy due to the insufficient O2 supply, inefficient reactive oxygen species (ROS) generation, and low penetration depth of light. In this work, a multifunctional nanoplatform, upconversion nanoparticles (UCNPs)@TiO2@MnO2 core/shell/sheet nanocomposites (UTMs), is designed and constructed to overcome these drawbacks by generating O2 in situ, amplifying the content of singlet oxygen (1O2) and hydroxyl radical (•OH) via water‐splitting, and utilizing 980 nm near‐infrared (NIR) light to increase penetration depth. Once UTMs are accumulated at tumor site, intracellular H2O2 is catalyzed by MnO2 nanosheets to generate O2 for improving oxygen‐dependent PDT. Simultaneously, with the decomposition of MnO2 nanosheets and 980 nm NIR irradiation, UCNPs can efficiently convert NIR to ultraviolet light to activate TiO2 and generate toxic ROS for deep tumor therapy. In addition, UCNPs and decomposed Mn2+ can be used for further upconversion luminescence and magnetic resonance imaging in tumor site. Both in vitro and in vivo experiments demonstrate that this nanoplatform can significantly improve PDT efficiency with tumor imaging capability, which will find great potential in the fight against tumor. Enhanced and amplified photodynamic therapy: A multifunctional nanoplatform, UCNPs@TiO2@MnO2 core/shell/sheet nanocomposites, is designed to overcome the drawbacks of photodynamic therapy by generating O2 in situ, amplifying the content of singlet oxygen (1O2) and hydroxyl radical (•OH) via water‐splitting, and utilizing 980 nm near‐infrared light to increase penetration depth, which significantly improves PDT efficiency as well as reduces the side effects.