Carbon dots/platinum nanoparticles-loaded mesoporous silica for synergistic photodynamic/catalytic therapy of hypoxic tumors

Abstract

The therapeutic efficacy of reactive oxygen species (ROS)-mediated cancer treatments is significantly limited by a shortage of substrates, such as hypoxia in photodynamic therapy (PDT). The development of an effective nanoplatform based on PDT toward hypoxic tumors remains a research imperative. Here, we report a triple ROS-generator, hyaluronic acid-modified Pt nanoparticles/carbon dots-loaded mesoporous silica (HA-PCD), which consists of Pt nanoparticles (NPs) and carbon dots (CDs)-loaded dendritic mesoporous silica nanoparticles (DMSNs) with further surface modifying hyaluronic acid (HA) for photodynamic/catalytic combination therapy of hypoxic tumors. Under 635 nm laser irradiation, HA-PCD generates singlet oxygen (¹O₂) due to the involvement of CDs photosensitizers. The loaded Pt NPs can not only enhance photodynamic therapy under hypoxic conditions by producing oxygen via catalase-mimicking activity, but also generate hydroxyl radicals (˙OH) and superoxide anions (O₂˙⁻) for catalytic therapy because of its peroxidase- and oxidase-mimicking activities. Additionally, due to the interaction between HA and overexpressed receptors (cluster determinant 44) in cancer cells, HA-PCD exhibits tumor cell targetability. In this work, a novel nanoplatform for multiple ROS-mediated synergistic photodynamic/catalytic therapy of hypoxic tumors has been fabricated.