Isolation and Profiling of Circulating Tumor ‐Associated Exosomes Using Extracellular Vesicular Lipid–Protein Binding Affinity Based Microfluidic Device

On ‐chip exosome isolation using immunoaffinity capture improves recovery from small sample volumes compared to ultracentrifugation. However, tetraspanins are not specific to cancer exosomes and some cancers secrete exosomes with low expression of tetraspanins. Here, a microfluidic‐device conjugate d with proteins against phosphatidylserine (PS), shown to be expressed on the outer surface of cancer‐associated exosome, is used to isolate cancer‐associated exosomes. AbstractExtracellular 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 ...
Source: Small - Category: Nanotechnology Authors: Tags: Full Paper Source Type: research