Sensitive and Selective Dual-Mode Responses to Reactive Oxygen Species by Chiral Manganese Dioxide Nanoparticles for Anti-Aging Skin.

Excessive accumulation of reactive oxygen species (ROS) can lead to oxidative stress and oxidative damage, which is one of the important factors for aging and age-related diseases. Therefore, real-time monitoring and the moderate elimination of ROS is extremely important. In this study, a ROS-responsive circular dichroic (CD) at 553 nm and magnetic resonance imaging (MRI) dual-signals chiral manganese oxide (MnO 2 ) nanoparticles (NPs) were designed and synthesized. Both the CD and MRI signals showed excellent linear ranges for intracellular hydrogen peroxide (H 2 O 2 ) concentrations, with limits of detection (LOD) of 0.0027 nmol/10 6 cells and 0.016 nmol/10 6 cells, respectively. The lower LOD achieved with CD detection may be attributable to its higher anti-interference capability from the intracellular matrix. Importantly, ROS-induced cell aging was intervened by chiral MnO 2 NPs via redox reactions with excessive intracellular ROS. In vivo experiments confirmed that chiral MnO 2 NPs effectively eliminated ROS in skin tissue, reduce oxidative stress levels, and alleviate skin aging. This approach provides a new strategy for the diagnosis and treatment of age-related diseases. This article is protected by copyright. All rights reserved.