UC San Diego

Since the discovery of ferrocene in 1951 and subsequent structure elucidation in the following years, a wealth of literature is available on ferrocene functionalization. The remarkable stability of ferrocene under aqueous and aerobic conditions along with its low cost and high availability has led to widespread popularity for usage in anticancer research.

Our research has explored the cytotoxicity of ferrocenyl anticancer agents with and without drug delivery carriers and possible mechanism of action within the tumor cells. We investigated selective generation of cytotoxic iron overload in tumor cells by synthesizing benzoyl-ferrocene and ferrocenyl chalcone derivatives. Photolysis of these two complexes lead to formation of free iron(II) in situ, which can react endogenously to form reactive oxygen species (ROS), such as hydroxyl radicals. This iron(II) would then be oxidized to iron(III) which could also react with endogenous ROS such as superoxide to reduce back to iron(II), resulting in catalytic generation of iron(II) which lends itself to unwanted, detrimental reactions within the cell. We propose a new method to photodynamic therapy (PDT) using generation of iron(II) in situ. We proposed that the generation of free iron(II) intracellular through this PDT method could induce ferroptosis and is actively pursuing experiments to determine if it is the case. We have also explored using porous silicon nanoparticles as a drug delivery carrier to ensure a higher iron payload delivery into cells, for greater cytotoxicity.