Chemical recognition of oxidation-specific epitopes in low-density lipoproteins by a nanoparticle based concept for trapping, enrichment, and liquid chromatography-tandem mass spectrometry analysis of oxidative stress biomarkers.

Monitoring bioactive oxidized phospholipids (OxPLs), such as 1- palmitoyl-2-(5′-oxovaleroyl)-sn-glycero-3- phosphocholine(POVPC) and 1- palmitoyl-2-(9′-oxononanoyl)-sn-glycero-3- phosphocholine(PONPC), is of major interest as they play a crucial role in a variety of age related diseases, e.g., in the development and progression of atherosclerosis. Since they are in low abundance in samples like oxidized low-density lipoproteins (OxLDL) and human plasma, respectively, their analysis as risk biomarkers requires the combination of an efficient selective sample preparation with highly sensitive detection methods, such as liquid chromatography– electrospray ionization- tandem mass spectrometry(LC–ESI-MS/MS). In this study, a nanoparticle-based strategy for successful trapping and enrichment of aldehyde-containing oxidized phospholipids is presented. The concept involves a derivatization step with a bifunctional reagent containing both a hydrazidegroup for hydrazoneformation with carbonyl-containing PLs and a th...