Fine control of the release and encapsulation of Fe ions in dendrimers through ferritin-like redox switching.

Numerous dendrimers incorporating metal ions or clusters have received much attention as catalytic and drug delivery materials. We expanded the variety of metal ions that complex with DPA through a radial stepwise complexation to create novel organic-inorganic hybrid materials. As one of the most common and significant iron ions, Fe3+ was used. It was confirmed that iron ions, FeCl3, are coordinated to the imine groups of a spherical phenylazomethine dendrimer (DPA) in a stepwise radial fashion, which should make it possible to control the number and location of the Fe3+ ions incorporated into the dendrimers. Iron possesses very interesting properties such as magnetism, redox chemistry, and catalysis and is also one of the essential elements of our body. Here, we show the first successful attempt to control the biomimetic switching of iron ions' release/encapsulation in the dendrimer driven by their redox response of the Fe2+/Fe3+ couple, which might find uses as a drug delivery system.