Titania-coated 2D gold nanoplates as nanoagents for synergistic photothermal/sonodynamic therapy in the second near-infrared window

• Published in: Nanoscale 2019-01, Vol.11 (5), p.2374-2384
• Main Authors: Gao, Fengli, He, Guangli, Yin, Hang, Chen, Jian, Liu, Yibiao, Lan, Chong, Zhang, Shouren, Yang, Baocheng
• Format: Article
• Language: English
• Subjects: Activation; Anticancer properties; Apoptosis; Cancer; Doppler effect; Electron traps; Gold; Heterostructures; Infrared windows; Low concentrations; Nanoparticles; Nanostructure; Photothermal conversion; Red shift; Size distribution; Therapy; Titanium dioxide; Toxicity
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c8nr07188h

The development of efficient nanomedicines to improve anticancer therapeutic effects is highly attractive. In this work, we firstly report titania-coated Au nanoplate (Au NPL@TiO 2 ) heterostructures, which play dual roles as nanoagents for synergistic photothermal/sonodynamic therapy in the second near-infrared (NIR) window. On the one hand, because the controlled TiO 2 shells endow the Au NPL@TiO 2 nanostructures with a red shift to the NIR II region, the as-prepared Au NPL@TiO 2 nanostructures possess a high photothermal conversion efficiency of 42.05% when irradiated by a 1064 nm laser and are anticipated to be very promising candidates as photothermal agents. On the other hand, the Au nanoplates (Au NPLs), as electron traps, vastly improve the generation of reactive oxygen species (ROS) by the Au NPL@TiO 2 nanostructures in contrast with pure TiO 2 shell nanoparticles upon activation by ultrasound (US) via a sonodynamic process. Moreover, the toxicity and therapeutic effect of the Au NPL@TiO 2 nanostructures were relatively systemically evaluated in vitro . The Au NPL@TiO 2 nanostructures generate a large amount of intracellular ROS and exhibit laser power density-dependent toxicity, which eventually induces apoptosis of cancer cells. Furthermore, a synergistic therapeutic effect, with a cell viability of only 20.3% upon both photothermal and sonodynamic activation, was achieved at low concentrations of the Au NPL@TiO 2 nanostructures. Experiments on mice also demonstrate the superiority of the combination of PTT and SDT, with the total elimination of tumors. This work provides a way of applying two-dimensional (2D) gold nanoplate core/TiO 2 shell nanostructures as novel nanoagents for advanced multifunctional anticancer therapies in the second NIR window. Au NPL@TiO 2 nanostructures play the dual role of heat- and ROS-generating agents, which lead to synergetic photothermal/sonodynamic therapy in the second biological window.