Pyrene-Based Aggregation-Induced Emissive Manganese Carbonyl Complex for Green Light-Controlled Carbon Monoxide (CO) Release and Theranostic Applications

Carbon monoxide (CO) has recently gained recognition as a therapeutic agent. A controlled and localized delivery of CO can be achieved through carbon monoxide-releasing molecules (CORMs). In this work, we report a new manganese-based CORM, Py-CO, which incorporates a pyrene fluorophore. Pyrene integration not only enables green light (525 nm)-triggered CO release but also imparts aggregation-induced emission (AIE) behavior, making Py-CO a dual-functional theranostic platform. The aggregation behavior of Py-CO was validated by scanning electron microscopy (SEM), fluorescence lifetime measurements, dynamic light scattering (DLS), and computational studies. Kinetic studies revealed a CO release rate constant of 0.1579 min –1 (half-life: 3.94 min) in the nonaggregated state, which increased to 0.3279 min –1 (half-life: 2.11 min) upon aggregation, underscoring the enhanced CO release dynamics in the aggregated state. The therapeutic significance of Py-CO was assessed in vitro using the human neuroblastoma SH-SY5Y cell line. Cytotoxicity assays confirmed its ability to induce cell death, demonstrating potential anticancer efficacy. Moreover, cellular uptake studies and bioimaging experiments revealed the feasibility of simultaneous imaging and therapy. Overall, Py-CO represents a novel class of light-activated, AIE-active CORMs that uniquely combine efficient CO release with intrinsic fluorescence, thereby enabling simultaneous therapeutic delivery and real-time imaging for potential cancer theranostics.