Isolation of cancer-derived extracellular vesicle subpopulations by a size-selective microfluidic platform

Abstract

Extracellular vesicles (EVs) play an important role in intercellular communication. Recently, there has been increasing interest in EVs as potential diagnostic biomarkers and therapeutic vehicles. However, the molecular properties and cargo information of EV subpopulations have not yet been fully investigated due to lack of reliable and reproducible EV separation technology. Current approaches have faced difficulties with efficiently isolating EVs from biofluids, especially subpopulations of small EVs. Here, we report an EV isolation method based on a size-selective microfluidic platform (ExoSMP) via nanomembrane filtration and electrophoretic force. This unique platform offers an enhanced approach to sorting a heterogeneous population of EVs based on size, with the additional advantages of being label-free and low-cost, and featuring a short processing time (<1 h), and convenient integration with downstream analysis. In this research, we used ExoSMP to demonstrate the isolation of cancer-derived small EVs (30–120 nm) with high recovery (94.2%) and reproducibility at an optimum sample flow rate. Furthermore, we investigated isolation of EV subpopulations by altering nanomembrane combinations with different pore size combinations (50 and 100 nm, 30 and 100 nm, 30 and 200 nm, and 30 and 50 nm). This ExoSMP technique can serve as a standardized EV isolation/separation tool, facilitating the clinical prospects of EVs and opening up a new avenue for future point-of-care applications in liquid biopsies.

Electrically driven microfluidic platforms for exosome manipulation and characterization

“…This role is reserved for a myriad of materials used for sieving. Several specific membranes for the isolation of EVs, including exosomes, have been reported in the literature [43–47]. For example, Davies et al.…”

Detection and Investigation of Extracellular Vesicles in Serum and Urine Supernatant of Prostate Cancer Patients

“…In general, PCa-associated exosomes were found to be characterized by a cargo containing cancer-related proteins such as CD9, CD81, and TSG101, Annexin A2, Fatty Acid Synthase (FASN), and prostate-specific membrane antigen (PSMA) [ 11 ]. The challenges in developing ideal early detection markers for PCa are outstanding, and numerous new blood-based and urinary biomarker models are emerging for usage in PCa detection, follow-up and treatment decision-making, despite current methods having faced complications with efficiently isolating EVs from biofluids [ 12 , 13 ]. One of the most tempting challenges would be that of better analyzing the exosome’s surface, as some groups recently reported in their studies using different approaches [ 14 ], and to deeply investigate more reliable isolation and analysis methods, focusing on a subset of circulating exosomes enriched for tumor origin, rather than total serum/plasma or urine exosomes [ 15 ].…”

Insights Into Exosomal Non-Coding RNAs Sorting Mechanism and Clinical Application

“…Owing to the rapid development of various exosome detection technologies in recent years, exosomal ncRNAs have become a specific and effective biomarker for clinical liquid biopsy (123)(124)(125). Methods of exosome isolation to date include ultracentrifugation (mostly approved for exosome purity), ultrafiltration, size-exclusion chromatography, polymer precipitation, immunoaffinity chromatography, and microfluidics-based techniques (126)(127)(128).…”