Radiation therapy for cancer can be a tradeoff between beneficial damage to tumors and harmful damage to healthy tissue.  To address this gamble, researchers at the Universities of Missouri and Tennessee, and the Oak Ridge National Laboratory have devised a layered nanoparticle delivery system that has high energy emitting actinium at its core, with four coatings of insulating material and a gold shell.  Attached antibodies deliver the particles to the tumor site.  Developers believe other alpha emitters, with varying degrees of radiation, might be delivered in the same way.  So far, testing has only been done with animals.   MORE