Metabolic landscaping of extracellular vesicles from body fluids by phosphatidylserine imprinted polymer enrichment and mass spectrometry analysis.

Extracellular vesicles (EVs) are emerging as new source of biomarkers discovery in liquid biopsy due to their stabilization in body fluids, protected by phospholipid bilayers. However, the metabolomics study of EVs is very little reported due to the lack of efficient and high-throughput isolation methods for clinical samples. In this study, phosphatidylserine imprinted polymers were employed for rapid and efficient EVs isolation from five human body fluids, including plasma, urine, amniotic fluid, cerebrospinal fluid, and saliva. The isolated EVs were subsequently analyzed for metabolomic studies by high-resolution mass spectrometry. Metabolic landscaping was conducted between the body fluids and their EVs, indicating EVs contain a large number of metabolites that are completely specific to the body fluid source. Finally, quantitative metabolomic analysis of EVs was carried out with plasma samples of hepatocellular carcinoma. Several differentially expressed exosomal metabolites were revealed including the upregulation of sphingosine (d18:1), taurochenodeoxycholic acid (TCDCA), pipecolic acid (PA), and 4-hydroxynonenal (4-HNE) and down-regulation of piperine, caffeine, and indole. We believe the proposed methodology will provide a deeper understanding of the molecular composition and functions of EVs as an alternative source for biomarker discovery.