Fully Integrated Centrifugal Microfluidics for Rapid Exosome Isolation, Glycan Analysis, and Point-of-Care Diagnosis

Abstract

Exosomes present in the circulatory system demonstrate considerable promise for the diagnosis and treatment of diseases. Nevertheless, the complex nature of blood samples and the prevalence of highly abundant proteins pose a significant obstacle to prompt and effective isolation and functional evaluation of exosomes from blood. Here, we present a fully integrated lab-on-a-disc equipped with two nanofilters, also termed iExoDisc, which facilitates automated isolation of exosomes from 400 μL blood samples within 45 min. By integrating the plasma separation module, highly abundant protein removal module, and nanopore membrane-based total isolation module, the resulting exosomes exhibited significantly increased purity (∼3-6-fold) compared to conventional ultracentrifugation and polymer precipitation. Additionally, we then successfully performed nontargeted and targeted glycan profiling on exosomes derived from clinical triple-negative breast cancer (TNBC) patients using MALDI-TOF-MS and lectin microarray containing 56 kinds of lectins. The findings from both methodologies indicated that galactosylation and sialylation exhibit potential as diagnostic indicators for TNBC. Finally, by utilizing the exosome-specific glycosylated protein CD63 as a proof-of-concept, we successfully realized the integration of point-of-care on-chip exosome separation and in situ detection with 2 h. Thus, the iExoDisc provides a potential approach to early cancer detection, liquid biopsy, and point-of-care diagnosis.

Keywords: breast cancer; diagnosis; exosome separation; glycan profiling analysis; microfluidic chip.