MicroRNA Extraction from Extracellular Vesicles by Nanowire Devices

Extracellular vesicles (EVs) are membrane-bound particles secreted by various cell types; EVs are found abundantly in body fluids, and they play significant roles in intercellular communication. Among the molecules contained in EVs, microRNAs are key regulators of gene expression, and they have been implicated in numerous diseases, including neurodegenerative disorders and cancers. Conventional methods for miRNA analysis, such as ultracentrifugation and immunoaffinity-based techniques, face challenges including the need for large sample volumes and low yield efficiency. To address these issues, our group has developed two types of innovative nanowire devices (inorganic nanowires composed of zinc oxide (ZnO) and organic nanowires composed of cellulose nanofibers) for the efficient capture and analysis of EV-derived miRNAs. In this chapter, we introduce the procedures for fabricating our inorganic and organic nanowire devices, as well as the methods for analyzing miRNAs extracted from EVs using the fabricated devices.