Oxidized Silicon Nanoparticles and Iron Oxide Nanoparticles for Radiation Therapy

Abstract

Our research objective is to develop superparamagnetic iron oxide nanoparticles and silicon nanoparticles as radiosensitizers for cancer therapy. After internalization by breast tumor cells and irradiation with X-rays, the nanoparticles were observed to enhance the oxidative stress in tumor cells. While silicon nanoparticles increase the reactive oxygen species production under X-ray treatment due to their incompletely oxidized surface, positively charged amino-functionalized silicon nanoparticles enhance the formation of mitochondrial reactive oxygen species formation because of their direct interaction with the mitochondrial membrane. On the other hand, uncoated and citrate-coated superparamagnetic iron oxide nanoparticles were found to increase the reactive oxygen species formation in X-ray treated tumor cells via two particular surface features, being, first, the leakage of iron ions and second, the catalytic activity of nanoparticle surfaces. Both may initiate the Haber-Weiss and Fenton reaction.