Biodegradable Prussian blue/manganese dioxide core–shell nanoparticles with open cages for imaging-guided chemo-photothermal combined therapy of cancer cells

Abstract

Imaging-guided diagnostic and therapeutic strategies have attracted significant attention in the field of nanomedicine. To develop more efficient theranostic nanoplatforms, this study designed and synthesized Prussian blue (PB)/manganese dioxide (MnO₂) core–shell nanoparticles with an open cage-like nanostructure (denoted as PBMn core–shell nanoparticles). In this nanoplatform, the PB core serves as a photothermal agent for near-infrared laser-induced photothermal therapy (PTT) against tumor cells, owing to its strong absorption in the NIR region and excellent stability. The MnO₂ shell, formed via the reduction of KMnO₄ by glucose, not only effectively modulates the size and optical properties of the PB core but also significantly depletes the intracellular glutathione (GSH) level in tumor cells. Moreover, the Mn²⁺ generated from the reduction of MnO₂ by highly concentrated GSH in the tumor microenvironment synergistically enhance both T₁- and T₂-weighted magnetic resonance imaging (MRI) signals, enabling high-contrast tumor imaging. Based on these features, the PBMn core–shell nanoparticles have been successfully applied for MRI-guided chemo-photothermal combination cancer therapy.