Native and synthetic ferritins for nanobiomedical applications: recent advances and new perspectives.

Ferritin is the protein whose function is to store iron that the cell does not require immediately for metabolic processes, thereby protecting against the toxic effects of free Fe(2+). Ferritin therefore plays a crucial role in iron metabolism as well as in the development of some diseases, especially those related to the presence of free Fe(2+) and toxic hydroxyl radicals. In addition, ferritin is itself a catalytic bionanoparticle. Its internal cavity can be used as a nanoreactor to produce non-native metallic nanoparticles. Moreover, its external protein shell can be chemically modified, allowing ferritin to be used as a precursor for a library of metallic nanoparticles, some which may have potential applications in biomedicine, especially as multimodal imaging probes. This article presents a brief overview of the evidence for the role of native ferritin in some diseases, as well as the potential of some synthetic ferritins--in which a non-native inorganic material has been introduced into the cavity and/or the external shell has been modified--in the field of nanobiomedicine.