The analysis of membranous extracellular vesicles, such as exosomes vesicles (EV) opens a new direction for the rapid disease diagnosis because EVs can carry molecular constituents of their originating cells. Secreted by mammalian cells, the size of most membrane-bound phospholipid EVs ranges from 50 to 150 nm in diameter. Recent studies have demonstrated the potential of using EVs for cancer diagnosis and treatment monitoring. To diagnose infectious diseases using EVs, the ability to discriminate EVs from host cells and parasites is key. Here, we report a rapid EV analysis assay that can discriminate EVs based on a host-specific transmembrane protein (CD63 antigen) using a label-free optical biosensor.
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Isolation and Profiling of Circulating Tumor‐Associated Exosomes Using Extracellular Vesicular Lipid–Protein Binding Affinity Based Microfluidic Device
Extracellular vesicles (EVs) are emerging as a potential diagnostic test for cancer. Owing to the recent advances in microfluidics, on‐chip EV isolation is showing promise with respect to improved recovery rates, smaller necessary sample volumes, and shorter processing times than ultracentrifugation. Immunoaffinity‐based microfluidic EV isolation using anti‐CD63 is widely used; however, anti‐CD63 is not specific to cancer‐EVs, and some cancers secrete EVs with low expression of CD63. Alternatively, phosphatidylserine (PS), usually expressed in the inner leaflet of the lipid bilayer of the cells, is shown to be expressed on the outer surface of cancer‐associated EVs. A new exosome isolation microfluidic device (newExoChip), conjugated with a PS‐specific protein, to isolate cancer‐associated exosomes from plasma, is presented. The device achieves 90% capture efficiency for cancer cell exosomes compared to 38% for healthy exosomes and isolates 35% more A549‐derived exosomes than an anti‐CD63‐conjugated device. Immobilized exosomes are then easily released using Ca2+chelation. The recovered exosomes from clinical samples are characterized by electron microscopy and western‐blot analysis, revealing exosomal shapes and exosomal protein expressions. ThenewExoChip facilitates the isolation of a specific subset of exosomes, allowing the exploration of the undiscovered roles of exosomes in cancer progression and metastasis.
more » « less- PAR ID:
- 10372436
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Small
- Volume:
- 15
- Issue:
- 47
- ISSN:
- 1613-6810
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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