Review on Strategies and Technologies for Exosome Isolation and Purification

Abstract

Exosomes, a nano-sized subtype of extracellular vesicles secreted from almost all living cells, are capable of transferring cell-specific constituents of the source cell to the recipient cell. Cumulative evidence has revealed exosomes play an irreplaceable role in prognostic, diagnostic, and even therapeutic aspects. A method that can efficiently provide intact and pure exosomes samples is the first step to both exosome-based liquid biopsies and therapeutics. Unfortunately, common exosomal separation techniques suffer from operation complexity, time consumption, large sample volumes and low purity, posing significant challenges for exosomal downstream analysis. Efficient, simple, and affordable methods to isolate exosomes are crucial to carrying out relevant researches. In the last decade, emerging technologies, especially microfluidic chips, have proposed superior strategies for exosome isolation and exhibited fascinating performances. While many excellent reviews have overviewed various methods, a compressive review including updated/improved methods for exosomal isolation is indispensable. Herein, we first overview exosomal properties, biogenesis, contents, and functions. Then, we briefly outline the conventional technologies and discuss the challenges of clinical applications of these technologies. Finally, we review emerging exosomal isolation strategies and large-scale GMP production of engineered exosomes to open up future perspectives of next-generation Exo-devices for cancer diagnosis and treatment.

Comparison of Human Urinary Exosomes Isolated via Ultracentrifugation Alone versus Ultracentrifugation Followed by SEC Column-Purification

“…While conventional ultracentrifugation is considered the gold standard for isolating exosomes from biological fluids [ 24 , 25 , 26 , 27 ], there are several other exosome isolation methods [ 35 ]. Over time, there have been newer techniques developed for exosome isolation, as well as attempts to improve older, more traditional exosome isolation methods, including conventional ultracentrifugation [ 23 , 26 , 27 , 38 ]. For instance, when high-yields of pure exosomal preparations are needed, density gradient ultracentrifugation has been shown to be superior when compared to ultracentrifugation and other exosome isolation techniques [ 23 , 25 , 39 , 40 , 41 ].…”

Conventional and Nonconventional Sources of Exosomes–Isolation Methods and Influence on Their Downstream Biomedical Application

“…Comparisons of recent strategies and technologies for EXs isolation and purification are described in many reviews ( Tang et al, 2017 ; Chen et al, 2019 ; Sidhom et al, 2020 ; Yang et al, 2020 ). Recently Chen et al focused on comparison of isolation methods with emphasis on the EXs yield and purity ( Chen et al, 2022 ). The very specific “smart” isolation method, which combines the aforementioned principles, are microfluidics-based methods( Yu et al, 2018 ; Yang et al, 2020 ; Zhou et al, 2020 ).…”

Microfluidic Platforms for the Isolation and Detection of Exosomes: A Brief Review

“…Therefore, at different elution times, several components can be separated. Thus, this method extensively isolates exosomes [ 40 , 41 , 42 ]. However, there is a high chance that exosomes or contaminant aggregates will get trapped in the pores, possibly damaging them.…”