Kunanon Chattrairat, Akira Yokoi, Min Zhang, Mikiko Iida, Kosuke Yoshida, Masami Kitagawa, Ayuka Niwa, Masatoshi Maeki, Takeshi Hasegawa, Takeshi Yokoyama, Yoshikazu Tanaka, Yusuke Miyazaki, Wataru Shinoda, Manabu Tokeshi, Kazuki Nagashima, Takeshi Yanagida, Hiroaki Kajiyama, Yoshinobu Baba, and Takao Yasui
Device, in press (2024). DOI:10.1016/j.device.2024.100363
MicroRNAs (miRNAs) are prospective biomarkers for diagnosis and prognosis due to their specific functions. Conventional methods lack the ability to discriminate two main miRNA sources-extracellular vesicle (EV)miRNAs and EV-free miRNAs (i.e., miRNAs not contained in EVs)-in one sample. Here, we demonstratethat a nanowire (NW) thermomicrofluidic device integrated with a Peltier temperature controller can captureEVs and EV-free miRNAs and then preferentially release the EV-free miRNAs by thermal energy and extractthe EV miRNAs via a lysis buffer. This leads to discrimination between EV miRNAs and EV-free miRNAs fromovarian cancer serum. Statistical analysis identified a relationship between miRNA source and tumor-relatedfunctions of the miRNAs: oncogenesis miRNAs were inside the EVs, and tumor-suppressor miRNAs wereoutside them. We demonstrate that the NW thermomicrofluidics provides the advantages of a simple, rapid,and effective method for miRNA extraction, accompanied by information from inside or outside the EVs.