ABSTRACT
Drug delivery systems (DDSs) represent an emerging technology for targeting necessary and sufcient amounts of therapeutic materials (small molecules or genes) to specic sites in a time-controlled manner. Recent developments in nanotechnology have led to the generation of new nanoparticles (NPs) that can function as nanocarriers, ranging in size from 50 to 150 nm in diameter. Composed of biocompatible materials, these NPs have been formulated into nanomedicines by incorporating therapeutic materials. Conventional nanocarriers have been classied into four groups (Kasuya and Kuroda 2009): (i) liposomes, nanocapsules consisting of a lipid bilayer; (ii) nanomicelles, NPs consisting of an amphiphilic diblock copolymer; (iii) polymers; and (iv) viruses.
