“…Two broad categories of nanotechnologies can be described: -'top-down' nanotechnologies involve creating nanoscale structures by machining and etching techniques; -'bottom-up' nanotechnologies are the novel synthesis of organic and inorganic structures, atom by atom, or molecule by molecule. …”

“…"Nanoparticles are the end products of a wide variety of physical, chemical and biological processes some of which are novel and radically different, others of which are quite commonplace. …”