Since a challenge of X-ray radiation therapy is that high dose X-ray can damage normal cells and cause side effects, this article reports on a new nanoparticle-based method to reduce X-ray dose in radiation therapy by internalization of gold nanoparticles that are modified with cationic molecules into cancer cells.
A cationic thiol molecule was synthesized and used to modify gold nanoparticles in a one-step reaction. The modified nanoparticles can penetrate cell membranes at high yield. By bringing radio-sensitizing gold nanoparticles closer to nuclei where DNA is stored, the total X-ray dose needed to kill cancer cells has been reduced. The simulation of X-ray-gold nanoparticle interaction also indicates that Auger electrons contribute more than photoelectrons. (publisher abstract modified)