Polyethylenimine-Coated Pt–Mn Nanostructures for Synergistic Photodynamic/Photothermal/Chemodynamic Tumor Therapy

How to develop antitumor nanodrugs with low toxicity and a good curative effect is an urgent problem in the current biomedicine field. In this work, different proposed composites were simulated by the finite difference time domain (FDTD) and COMSOL, including the material element, refractive index, particle size, and shape. Also, different machine learning algorithms are utilized to predict the absorbance at the near-infrared laser of 980 nm of different materials. Through train, validation, and test, the prediction of the as-synthesized Pt–Mn has high absorbance. Then, inorganic Pt–Mn was coated with PEI in order to improve their biocompatibility. Pt–Mn nanoparticles can generate ROS under the single 980 nm laser irradiation as a photodynamic therapy (PDT) agent and as a photothermal therapy (PTT) agent to heat the cells with a photothermal conversion efficiency of 23.6%. In addition, the electrochemical and in vitro chemodynamic therapy (CDT) experiments prove that Pt–Mn nanozymes could mimic the activity of peroxidase and enhance the Fenton reaction, thereby catalyzing excess H2O2 to produce hydroxyl free radicals and illustrating the potential to induce tumor cell apoptosis as the CDT agent in a weakly acidic tumor environment to complete high-efficiency chemokinetic therapy. Finally, Pt–Mn–PEI nanoparticles were used for PDT/PTT/CDT and the immune checkpoint inhibitor of anti-PD-L1 is injected in order to obtain the assistant immunotherapy, providing a potential choice to anticancer through effective synergistic cancer therapies.