Ferritin-assisted biomineralization and drug delivery: It's a matter of hard and soft.

This review focuses on two main activities that have been the subject of research in our group during the last 15 years that concerns i) tracking of the iron(II) pathways in the ferritin cage to reach the ferroxidase site or the nucleation sites as well as identifying the interactions between the protein matrix and the iron(III) products; ii) identifying the binding mode of gold(I) metal compounds to the cage surface for their targeted delivery towards cancer cells. The resulting metal interaction sites in the protein cage can be categorized based on their preference for binding to hard or soft cations.