Silver ions and nanosilver-containing coatings are well known for their biocide effects. After exposure to ionic silver or to a nanosilver-containing plasma coating, cells observed by scanning transmission electron microscopy (STEM) show the same visual aspect, namely, the presence of electron-dense nodules all over the cell. These observations could indicate that the interaction of silver with the cells is similar in both cases, and probably, that the reactivity of silver ions should only dominate the physicochemical interactions with cells. In fact, a deeper analysis by energy dispersive spectroscopy (EDS) and microdiffraction of electron-dense nodules reveals that the Ag+ and nanosilver interactions with the cells seem to be dissimilar and lead to the formation of clusters with a different chemical and structural nature.
http://nanotechweb.org/cws/article/lab/45701