Here is a recent article relevant for our interest in Silver Oxide particles 
and metallic silver particles.   A molecular biologist and a nanoscientist at 
the University of Central Florida have found that nanomaterials developed for 
industry have an unexpected and potentially revolutionary side effect: They can 
triple or quadruple the life of brain cells  at 
http://news.nanoapex.com/modules.php?name=News&file=article&sid=3709
John (Biophysica.com)