Immunogenic cell death-inducing Rh(I) and Ir(I) complexes with bis(imino)acenaphthene-derived ligands: Insights into the role of the metal center and the ligands

Abstract

While various metal complexes demonstrated immunogenic cell death (ICD)-inducing properties, there is a lack of studies comparing ICD properties in structurally similar complexes with different metal centers. In this study, we synthesized four structurally similar Rh(I) and Ir(I) complexes with redox-active 1,2-bis(arylimino)acenaphthene (Ar-bian) ligands and assessed their anticancer and ICD-inducing properties. Analysis of danger-associated molecular patterns (DAMPs) and dying cell populations highlighted the distinct role of the metal center, with the contribution of the ligand being less evident. Specifically, only Rh(I) complexes induced the release of the three essential DAMPs and high levels of late apoptotic cells, while the Ir(I) complexes failed to trigger crucial "eat-me" signals. This work offers valuable insights into understanding of structure-activity relationships in metal complexes in the context of ICD.