Pulmonary iron oxide (Fe₃O₄) nanoparticle-biomolecule interactions modified during aging and metabolic syndrome...

IntroductionAging and metabolic disease enhance inhaled particulate toxicity. Nanoparticles (NPs) are rapidly coated with biomolecules forming a biocorona (BC), upon entering the body and may contribute to the susceptibility. Aging and metabolic syndrome (MetS) are progressive conditions resulting in biomolecule alterations over time potentially influencing susceptibility. We hypothesize NP-biomolecule interactions are altered during aging and throughout MetS progression.MethodsC57BL/6J mice at 6 weeks of age were fed a healthy diet or a high-fat western diet. BALF was collected after 2, 4, 8, 12, 16, 20 or 24 weeks on diets. NP-biomolecules interactions were compared between healthy and MetS to determine age- and disease progression-related BC variations (proteins and lipids).ResultsUnique BCs were determined to form at each time point indicative of aging for the healthy and aging and disease progression for the MetS. Comparisons between healthy and MetS BCs at each time demonstrated distinct biomolecule interactions attributable to disease. Comparisons determined both unique protein and lipid content as well as quantitative differences. Proteins such as apolipoprotein A-IV, complement C3 and lipids such as PE (37:5), PE (O-38:5), PE (P-38:4), PC(40:7), PC(39:0), and PC(O-40:0) were identified on the MetS BC suggesting disease progression modifications. Proteins such as pulmonary surfactant protein A, fibrinogen alpha-chain and lipids such as CE (19:0)-NH4, DG (36:7), and DG (35:0)_C18:0 were increasingly present in the healthy BC over time, suggesting age-related interactions.DiscussionOverall, unique BCs were identified demonstrating the impact of age and disease progression on BC formation which will aid in understanding initial pulmonary NP-biomolecular interactions potentially contributing to susceptibility.