Nanogene droids were a highly experimental form of automaton which were microscopic in size. The purpose of the droid was to affect a living organism on a cellular level. Once injected into the body they would attack the genetic code of the organism and, essentially, rewrite it. Due to this, the 'victim' would possibly suffer from some highly unusual side effects due to the changes made on a molecular scale. The project that was producing these droids was abandoned during the final years of the New Order as the droids were seen as too costly for widespread use.
Production of the droids was restarted by a scientist called Uris who did so with his own funding. The droids were programmed to alter the genetic structure of the people of the planet Voorsbain and turn the inhabitants into mindless zombies within a span of three weeks. They were almost unleashed on the defenseless world but the attempt was stopped by Rebel Alliance agents.