Photodynamic Therapy Using Pulsed-Laser Irradiation of Gold Nanoparticles for the Treatment of Cancers with High Basal Oxidative Stress

For over 20 years, considerable research has been carried out on the use of nanotechnologies in cancer treatment. Beyond the photothermal effect of irradiating gold nanoparticles, the photodynamic effect with reactive oxygen species (ROS) production at the tissue level is poorly known. We showed that renal cancers had high basal ROS levels. We engineered different gold nanoparticles and optimized the irradiation parameters. Then, we intravenously injected several patient-derived xenografts with tailored gold nanorods that we irradiated using a pulsed laser. We optimized irradiation parameters to decrease toxic effects on normal tissue and showed that the local monitoring of skin temperature was an accurate marker for predicting histological toxicity. We demonstrated a significant additional effect of irradiating gold nanoparticles, with the increased activation of the autophagy pathway following irradiation, associated with the disappearance of renal cancer cells. Our study highlights the elevated ROS levels in cancers as a potential therapeutic target for ROS-mediated cytotoxicity therapies.