Nanobiosystems.

'Nanobiosystems' is a relatively new term describing objects in the size range below 150 nm and having structures or functions that link to biological functions. Key features are that these nanosized objects typically self-assemble, are not capable of self-replication, and have functions that take advantage of its size. Nanobiosystems can be made entirely of biological or organic molecules that are organized into nanoparticles (e.g., liposomes, dendrimers) or be totally inorganic (with the exception of surface coatings used for biocompatibility) nanoparticles (e.g., gold, iron oxide, quantum dot nanocrystals). More complex nanobiosystems are inorganic/biologic hybrid composites that may include complex multilayered structures with targeting molecules (e.g., peptides, antibodies, aptamers), cell entry-promoting molecules (e.g., HIV-tat peptide sequence), drugs (small molecules), genes (therapeutic genes, reporter genes), and core nanomaterials (e.g., gold, quantum dot, iron oxide) that give the nanobiosystems sometimes unique detection capabilities by a variety of optical and non-optical modalities (fluorescence, surface plasmon resonance, magnetic resonance imaging).