Au-Pt Nanoparticle Formulation as a Radiosensitizer for Radiotherapy with Dual Effects

Background: Radiotherapy occupies an essential position as one of the most significant approaches for the clinical treatment of cancer.However, we cannot overcome the shortcoming of X-rays which is the high value of the oxygen enhancement ratio (OER).Radiosensitizers with the ability to enhance the radiosensitivity of tumor cells provide an alternative to changing X-rays to protons and heavy ion radiotherapy. Materials and Methods:We prepared the Au-Pt nanoparticles (Au-Pt NPs) using a onestep method.The characteristics of the Au-Pt NPs were determined using TEM, HAADF-STEM, elemental mapping images, and DLS.The enhanced radiotherapy was demonstrated in vitro using MTT assays, colony formation assays, fluorescence imaging, and flow cytometric analyses of the apoptosis.The biodistribution of the Au-Pt NPs was analyzed using ICP-OES, and thermal images.The enhanced radiotherapy was demonstrated in vitro using immunofluorescence images, tumor volume and weigh, and hematoxylin & eosin (H&E) staining.Results: Polyethylene glycol (PEG) functionalized nanoparticles composed of the metallic elements Au and Pt were designed to increase synergistic radiosensitivity.The mechanism demonstrated that heavy metal NPs possess a high X-ray photon capture crosssection and Compton scattering effect which increased DNA damage.Furthermore, the Au-Pt NPs exhibited enzyme-mimicking activities by catalyzing the decomposition of endogenous H 2 O 2 to O 2 in the solid tumor microenvironment (TME). Conclusion:Our work provides a systematically administered radiosensitizer that can selectively reside in a tumor via the EPR effect and enhances the efficiency of treating cancer with radiotherapy.