Development of a Microfluidic Device for Exosome Isolation in Point-of-Care Settings

Exosomes have gained recognition in cancer diagnostics and therapeutics. However, most exosome isolation methods are time-consuming, costly, and require bulky equipment, rendering them unsuitable for point-of-care (POC) settings. Microfluidics can be the key to solving these challenges. Here, we present a double filtration microfluidic device that can rapidly isolate exosomes via size-exclusion principles in POC settings. The device can efficiently isolate exosomes from 50-100 mu L of plasma within 50 min. The device was compared against an already established exosome isolation method, polyethylene glycol (PEG)-based precipitation. The findings showed that both methods yield comparable exosome sizes and purity; however, exosomes isolated from the device exhibited an earlier miRNA detection compared to exosomes obtained from the PEG-based isolation. A comparative analysis of exosomes collected from membrane filters with 15 nm and 30 nm pore sizes showed a similarity in exosome size and miRNA detection, with significantly increased sample purity. Finally, TEM images were taken to analyze how the developed devices and PEG-based isolation alter exosome morphology and to analyze exosome sizes. This developed microfluidic device is cost-efficient and time-efficient. Thus, it is ideal for use in low-resourced and POC settings to aid in cancer and disease diagnostics and therapeutics.

Automated summary

This study presents a double filtration microfluidic device that can rapidly isolate exosomes via size-exclusion principles in point-of-care settings. The device efficiently isolates exosomes from plasma samples within 50 minutes and exhibits earlier miRNA detection compared to a polyethylene glycol-based method. Comparative analysis of exosomes collected from different pore sizes of membrane filters shows increased sample purity. The developed microfluidic device is cost-efficient and time-efficient, making it ideal for cancer and disease diagnostics and therapeutics in low-resourced and point-of-care settings.