Imaging the Adverse Effects of Tire-Derived Contaminants via Coelenterazine-Facilitated Albumin Luminescence In Vivo

Abstract The widespread use of automotive tires has resulted in the global distribution of tire-derived contaminants in the environment. In this study, we developed a versatile molecular imaging platform using novel synthesized coelenterazine (CTZ) analogs to quantitatively assess the impacts of tire additives and the primary oxidation products, 6PPD and 6PPD-Q, in vitro and in vivo. The results indicate that these compounds competitively block the interaction of CTZ analogs with serum albumins, suppressing luminescence signals. Specifically, 6PPD significantly reduced CTZ-facilitated luminescence in vitro, with pronounced suppressive effects observed for rabbit (55%) and porcine (65%) serum albumins. Interestingly, 6PPD and 6PPD-Q also suppressed human serum albumin (HSA)-facilitated CTZ luminescence by 31% and 47% respectively, depending on the specific CTZ indicator utilized. Collectively, these findings demonstrate that 6PPD and 6PPD-Q significantly interfere with the normal ligand-binding capacity of serum albumins across various species, including humans. This work contributes to ongoing efforts to evaluate and mitigate the ecological and public health risks posed by emerging contaminants from automotive vehicles.