From biogenesis to aptasensors: advancements in analysis for tumor-derived extracellular vesicles research

Abstract

Extracellular vesicles (EVs) are enclosed by a nanoscale phospholipid bilayer membrane and typically range in size from 30 to 200 nm. They contain a high concentration of specific proteins, nucleic acids, and lipids, reflecting but not identical to the composition of the parent cell. The inherent characteristics and variety of EVs give them extensive and unique advantages in the field of cancer identification and treatment. Recently, EVs have been recognized as potential tumor markers for the detection of cancer. Aptamers, which are molecules of single-stranded DNA or RNA, demonstrate remarkable specificity and affinity for their targets by adopting distinct tertiary structures. Aptamers offer various advantages over their protein counterparts, such as reduced immunogenicity, the ability for convenient large-scale synthesis, and straightforward chemical modification. In this review, we summarized EVs biogenesis, sample collection, isolation, storage and characterization, and finally provided a comprehensive survey of analysis techniques for EVs detection that are based on aptamers.

Keywords: Aptamers; Detection; Extracellular Vesicles; Tumor Markers.

Figure 1

Schematic illustration of analysis for tumor-derived extracellular vesicles, from biogenesis to the development of aptasensors.

Figure 2

Biogenesis and contents of EVs. Exosomes are generated via the double invagination of the PM, including the formation of early sorting endosomes (ESEs) and late sorting endosomes (LSEs), the generation of ILVs within MVBs, the transportation of MVBs to cytoplasmic membrane, and the fusion of MVBs membrane with the cell membrane. Cargo exchange occurs between ESEs (LSEs) and the trans-Golgi network. MVBs can also fuse with lysosomes or autophagosomes for the degradation and recycling of cellular contents. Microvesicles are derived from the direct outward budding of cellular PM. EVs, including exosomes, transport a vast repertoire of different types of proteins, lipids, NAs, and other small molecules. Adapted with permission from , copyright 2021 American Chemical Society.

Figure 3

Schematic diagram of liquid biopsy. Adapted with permission from , copyright 2021 American Chemical Society.

Figure 4

Schematic representation of common exosomal separation techniques. (A) Ultracentrifugation, (B) Density gradient centrifugation. Adapted with permission from , copyright 2022 Frontiers.

Figure 5

Schematic diagram of SELEX for aptamer selection. Adapted with permission from , copyright 2021 American Chemical Society.

Figure 6

Schematic diagram for P-ERCA. Adapted with permission from , copyright 2021 Elsevier.

Figure 7

Schematic representation of the detection of surface proteins of sEVs using a dual color DNA nanodevice based on an enzyme-free signal amplification and synchronous fluorescence technique. Adapted with permission from , copyright 2022 American Chemical Society.

Figure 8

Illustration of the ABDN-based TIRF assay for single-vesicle imaging and detection of circulating tumor-specific Exos in plasma. Adapted with permission from , copyright 2019 American Chemical Society.

Figure 9

Principle of the aptamer-initiated CHA (AICHA) signal amplification strategy for exosome detection. H1 was modified with a FAM fluorophore and BHQ2 quencher. SA-MB: streptavidin-modified magnetic beads. Biotin-aptamer: biotin modified aptamer. Adapted with permission from , copyright 2022 American Chemical Society.

Figure 10

Principle of the ECL biosensor for exosomes detection based on in situ formation of gold nanoparticles decorated Ti₃C₂ MXenes nanoprobes. Adapted with permission from , copyright 2020 American Chemical Society.

Figure 11

Principle of the paper-based biosensor for exosome assay. Adapted with permission from , 2021 American Chemical Society.

Figure 12

Schematic illustration of the DNA-driven photothermal amplification transducer for highly sensitive visual determination of EVs. Adapted with permission from , copyright 2023 American Chemical Society.

Figure 13

Schematic of λ-DNA-mediated sorting of EV subpopulations and aptamer-based analysis of individual EVs. (A) Labeling of cell-originating EVs including exosomes (EXOs, red), microvesicles (MVs, green), and apoptotic bodies (ABs, blue) with fluorescent HER2 and EpCAM aptamers. (B) Size-selective separation of EV subpopulations by λ-DNA mediated viscoelastic microfluidics. Fluorescence microscopy images showed HER2 (red) and EpCAM (green) expression of isolated individual EVs. Scale bar, 5 μm. Adapted with permission from , copyright 2019 American Chemical Society.