Hyun-Kyung Woo†‡, Vijaya Sunkara†‡, Juhee Park⊥, Tae-Hyeong Kim⊥, Ja-Ryoung Han†, Chi-Ju Kim†⊥, Hyun-Il Choi§, Yoon-Keun Kim§∥, and Yoon-Kyoung Cho*†⊥
† Department of Biomedical Engineering, School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
§ Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
∥ Institute of MD Healthcare, Seoul 03923, Republic of Korea
⊥ Center for Soft and Living Matter, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
‡These authors contributed equally to this work.
Extracellular vesicles (EVs) are cell-derived, nanoscale vesicles that carry nucleic acids and proteins from their cells of origin and show great potential as biomarkers for many diseases, including cancer. Efficient isolation and detection methods are prerequisites for exploiting their use in clinical settings and understanding their physiological functions. Here, we presented a rapid, label-free, and highly sensitive method for EV isolation and quantification using a lab-on-a-disc integrated with two nanofilters (Exodisc). Starting from raw biological samples, such as cell-culture supernatant (CCS) or cancer-patient urine, fully automated enrichment of EVs in the size range of 20-600 nm was achieved within 30 min using a tabletop-sized centrifugal microfluidic system. Quantitative tests using nanoparticle-tracking analysis confirmed that the Exodisc enabled >95% recovery of EVs from CCS. Additionally, analysis of mRNA retrieved from EVs revealed that the Exodisc provided >100-fold higher concentration of mRNA as compared with the gold-standard ultracentrifugation method. Furthermore, on-disc enzyme-linked immunosorbent assay using urinary EVs isolated from bladder cancer patients showed high levels of CD9 and CD81 expression, suggesting that this method may be potentially useful in clinical settings to test urinary EV-based biomarkers for cancer diagnostics.
Keywords: bladder cancer; ELISA; extracellular vesicles; lab-on-a-disc; size-based filtration