Methods and Technologies for Exosome Isolation and Characterization

Abstract

Exosomes, a specific subclass of the extracellular vesicles secreted by most cell types, play an important role in cell–cell communication by transporting diverse content including protein, mRNA, miRNA, and DNA. This cargo is closely associated with the pathogenesis of most human malignancies. Therefore, it is becoming an urgent demand to be able to isolate exosomes in a simple, efficient, and economical way for scientific research and clinical diagnosis. Here, several conventional and novel nano‐based techniques of exosome isolation and characterization are summarized, and the advantages and disadvantages among them are compared, with the hope that researchers will be provided with an overview in this field to detect and isolate exosomes in a suitable manner, matching the subsequent experiments.

Progress in Microfluidics‐Based Exosome Separation and Detection Technologies for Diagnostic Applications

“…The separation efficiency of this technique fully depends on the sample density and the distance the components of the sample can travel. Thus, the heterogeneity of vesicles results in low‐purity exosome separation . Gradient density ultracentrifugation is a better alternative to obtain higher separation purity.…”

“…Zarovni et al used nanomagnetic beads to immunocapture exosomes, and the results showed that the yield of exosomes was 10–15 times higher than that when using ultracentrifugation‐based separation techniques . Although immunological separation techniques for exosomes have the advantages of high‐purity isolation and a simple procedure, the requirements of nonphysiological salt and pH conditions, costly reagents, and cell‐free samples result inhibit the use of these separation techniques for large‐scale exosome separation …”

“…Thus, the heterogeneity of vesicles results in low-purity exosome separation. [111] Gradient density ultracentrifugation is a better alternative to obtain higher separation purity. The major difference between differential ultracentrifugation and gradient density ultracentrifugation is that the latter uses two or more solutions or gels with different densities.…”

“…[120] Although immunological separation techniques for exosomes have the advantages of high-purity isolation and a simple procedure, the requirements of nonphysiological salt and pH conditions, costly reagents, and cell-free samples result inhibit the use of these separation techniques for large-scale exosome separation. [64,111,121]…”

A MoS2–MWCNT based fluorometric nanosensor for exosome detection and quantification

“…5 Recent studies further revealed that many biological uids (including saliva, lymph, urine, milk, blood, synovial and amniotic uids) contain vesicles which are released by early-stage tumors and carry various tumor markers. [6][7][8] These micro-and nano-vesicles are potentially measurable in easily accessible body uids and can be useful as a diagnostic and prognostic biomarker for early detection of many diseases and disorders, mainly, as essential indicators of the state and progression of cancer. 9 According to previous studies, exosomes originating from tumors are an invaluable source of cancer biomarkers.…”