Oral Presentation Australasian Extracellular Vesicles Conference 2018

Microfluidic Affinity Separation Chip for Selective Capture and Release of Label-free Extracellular Vesicles (#5)

Colin L Hisey 1 2 , Kalpana DP Dorayappan 3 , David E Cohn 3 , Selvendiran Karuppaiyah 3 , Derek J Hansford 1
  1. Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
  2. Hub for Extracellular Vesicle Investigations, University of Auckland, Grafton, Auckland, New Zealand
  3. Division of Gynecologic Oncology, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, USA

Exosomes are nanoscale extracellular vesicles (EVs) that can play a significant role in cell-to-cell signaling and contain biomolecules indicative of their cells of origin. Recently, microfluidic devices have provided the ability to efficiently capture EVs based on specific membrane biomarkers, but releasing the captured EVs intact and label-free remains a challenge. We present a herringbone-grooved microfluidic device which is covalently functionalized with antibodies against general and cancer over-expressed exosome membrane proteins (CD9 and EpCAM) to isolate EVs from small volumes of high-grade serous ovarian cancer (HGSOC) serum. Following capture, intact EVs are released label-free using a low pH buffer and immediately neutralized downstream to ensure their stability for further analysis or experimentation. Characterization of captured and released EVs was performed using fluorescence microscopy, nanoparticle tracking analysis, flow-cytometry, and SEM. Our results demonstrate the successful isolation of intact and label-free EVs and indicate that the amount of both total and EpCAM positive EVs increases with HGSOC disease progression (p<0.05). Furthermore, using confocal microscopy we verified that these EVs remain biologically active and can be readily internalized in cell cultures. This device and approach can be utilized for a nearly limitless range of downstream EV analytical and experimental techniques, both on and off-chip.