Perspectives and challenges in extracellular vesicles untargeted metabolomics analysis

The discovery of extracellular vesicles (EVs), including exosomes, microvesicles, and apoptotic bodies, has opened a new frontier in the study of signal transduction and understanding cell-to-cell communication. EVs play a key role regulating various biological processes such as tissue regeneration, blood coagulation, immunomodulation or carcinogenesis. Therefore, they gain much attention as potentially therapeutic and non-invasive diagnostic targets. In this aspect, a comprehensive characterization of the EVs molecular content and understanding EVs functions are especially relevant. However, routine isolation of a usually small amount of high purity EVs is challenging, and analysis requires highly sensitive advanced analytical solutions. The utility of EVs in clinical settings is still limited due to the lack of standardization in existing protocols. This review focuses on the implication of the state-of-the-art mass-spectrometry based untargeted metabolomics approach for the molecular profiling of EVs, with the emphasis on the analytical methodologies, highlighting potential challenges and limitations.