Salivary Extracellular Vesicles: Paradigm Shift in Liquid Biopsy Diagnostics

Extracellular vesicles (EVs), lipid bilayer nanoparticles released by virtually all cells, serve as essential messengers for intercellular communication. Due to their involvement in several pathophysiological processes, EVs have recently gained considerable attention as potentially diagnostic and prognostic biomarkers for various illnesses. The widespread distribution of EVs across all biofluids positions them as ideal, minimally invasive biomarkers for disease progression using a liquid biopsy approach. Among biofluids, saliva is uniquely accessible and has a low soluble protein content, making its EV population a highly promising source of diagnostic biomarkers. Salivary EVs have been investigated for their promising potential for diagnosing local and systemic diseases, including cancers, autoimmune diseases and neuropsychiatric disorders. In this review, we present a synopsis of the current landscape related to salivary EVs, highlighting the unique characteristics and potential of these vesicles, the technical challenges related to their application, and their future prospects for clinical translation as powerful diagnostic tools.