Cerium Niobate Hollow Sphere Engineered Graphitic Carbon Nitride for Synergistic Photothermal/Chemodynamic Cancer Therapy

Abstract

Reactive oxygen species (ROS)-mediated chemodynamic therapy (CDT) and photothermal therapy (PTT) have potential for various cancer treatments. However, they are still bound by the demands of Fenton reaction conditions such as oxygen dependence, inherent defects in common standard photosensitizers (PSs), and the continuous availability of laser sources. Herein, we designed Ce3NbO7/g-C3N4 nanocomposites (NCs) and investigated their ability to evaluate the performance of PTT/CDT synergistically to enhance cancer treatment. The activation of Ce3NbO7/g-C3N4 NCs in the tumor microenvironment (TME) causes the generation of cytotoxic ROS via the Fenton reaction. Additionally, the g-C3N4 in NCs absorbs NIR, generating hyperthermia in the TME. The photothermal conversion efficiency (ƞ) of the Ce3NbO7/g-C3N4 NCs was found to be 49.5%. A photocatalytic reaction with PTT-enhanced Fenton reagents, without consuming additional photothermal agents (PTA) or Fenton reagents, generates the hydroxyl radical (OH•) primarily by direct electron transfer in the TME. Almost 68% of cells experienced programmed cell death due to the combinational effect (PTT/CDT), making it an efficient and biocompatible therapy. Furthermore, this work provides a basis for developing numerous innovative materials that can be used to treat cancer, overcome general limitations, and enhance ROS production under single-wavelength (808 nm) laser irradiation.

Keywords

• chemodynamic therapy
• photothermal therapy
• tumor microenvironment
• Fenton reaction