Fe in biosynthesis, translocation, and signal transduction of NO: toward bioinorganic engineering of dinitrosyl iron complexes into NO-delivery scaffolds for tissue engineering

Iron, the most abundant transition metal ion in humans, participates in the biosynthesis, translocation, signal transduction, and transformation of nitric oxide through its encapsulation in the form of heme, [Fe–S], and [Fe(NO)2] cofactors within a variety of enzymes and proteins. After the review on nitric oxide synthase (NOS) and soluble guanylate cyclase (sGC) for the biosynthesis and detection of NO, in this report, we discuss the natural utilization of the [Fe(NO)2] motif for translocation of endogenous NO and the translational development of synthetic dinitrosyl iron complexes (DNICs) for biomedical applications. A mechanistic study of NO-release and NO-transfer reactivity of structure-characterized DNICs promoted the discovery of cell-penetrating and in vivo NO-delivery reactivity for treatment of cancer and wound healing in diabetes. Beyond activation of sGC and vasodilation, phase I/II clinical trials of glutathione-bound DNICs (Oxacom®) against hypertension encourage bioinorganic engineering of DNICs into scaffolds for tissue regeneration and repair relying on anti-bacterial, anti-inflammation, cytoprotective, and proliferative effects of NO.