Biodegradable Silica-Based Nanotheranostics for Precise MRI/NIR-II Fluorescence Imaging and Self-Reinforcing Antitumor Therapy.

Multi-modality cancer diagnosis techniques based on the second near-infrared window fluorescence (NIR-II FL, 1000-1700 nm) imaging have become the focus of research attention. For such multimodality probes, how to take advantage of the tumor microenvironments (TME) characteristics to better image diseases and combine efficient therapeutics to achieve theranostics is still a big challenge. Herein, a novel TME-activated nanosystem (FMSN-MnO -BCQ) employing degradable silica-based nanoplatform is designed, adjusting the ratio of intratumoral hydrogen peroxide (H O )/glutathione (GSH) for magnetic resonance imaging (MRI)/NIR-II FL imaging and self-reinforcing chemodynamic therapy (CDT).