Exosomes are small (30-200 nm) cell-specific, membrane-bound structures, also known as extracellular vesicles (EVs). They originate in the endosomal compartment and transport nucleic acids, proteins, and lipids derived from the parent cell. Once released into the extracellular space, they are taken up by target cells and mediate the cell-to-cell communication.
Exosome research has exploded over the last few years, especially in the areas of diagnostic biomarkers and drug delivery. As of January 2023, there are at least 204 ongoing clinical trials globally focusing on exosome-related studies. Of these, 114 trials are evaluating exosome-based therapeutics, and 74 trials are assessing exosome-based diagnostic tests. (Source: Cade Hildreth).
Exosomes have been shown to affect the physiological and pathogenesis of multiple diseases, including:
The molecular cargo of exosomes varies by cell type, developmental stage, and physiological state of the cell. For example, cancer cell-derived exosomes transport DNA, RNA, and proteins that are tumor specific, and different from those of non-malignant cells. They influence cell proliferation and migration and affect both the development of the tumor microenvironment and the response to traditional therapies.
One key advantage of exosomes is their ability to be isolated through minimally invasive methods. They can be isolated from a variety of body fluids, including, blood, urine, saliva, and cerebrospinal fluid, making them a highly attractive target for diagnostic purposes, otherwise known as liquid-biopsy-based diagnostics.
Exosomes can also be isolated from cell culture media from established cell lines and primary cells.
Exosome isolation can be done using multiple techniques, including polymer precipitation, anion and cation exchange chromatography, and size-exclusion chromatography. Specific populations of exosomes can be obtained through antibody-based enrichment (immunoaffinity). Exosomes can be isolated from liquid biopsy samples such as blood, serum, plasma, urine, saliva, and cerebrospinal fluid.
While ultracentrifugation is a commonly used approach for exosome enrichment, there are advantages to using ion-exchange chromatography (e.g., Q-Sepharose) and size-exclusion chromatography as multi-step exosome purification:
With over 450+ cell lines and primary cells available at SBH Sciences, we provide unmatched flexibility in exosome sourcing. SBH has used Invitrogen TM Total Exosome Isolation Reagent (from cell culture media) Cat. # 4478359 to facilitate efficient isolation from our cell lines.
SBH Sciences offers comprehensive exosome characterization services through our established drug discovery platforms including molecular biology, bioanalytical, and cell-based assays.
Molecular biology
DNA purification, PCR-based analysis of exosome DNA content (qPCR, dPCR, isothermal amplification). RNA purification, gene expression analysis (RT-qPCR). Development and validation of novel assays for nucleic acid-based biomarkers.
Bioanalytical
Development, validation, and application of bioanalytical methods to detect and measure protein content in purified exosomes. Multiple platforms for protein biomarker analysis, including ELISA, Simple Plex (ELLA), Multiplex (Luminex), fully automated western blot (JESS, ProteinSimple), single-color and multi-color flow cytometry.
Cell-based Assays
In vitro assays are an integral part of the development of exosome-based therapeutics. With hundreds of cell lines and validated cell-based assays, we can develop and perform functional assays for exosome effects in multiple therapeutic areas. These include:
Invitrogen™ Total Exosome Isolation Kit: Efficient polymer-precipitation method that isolates exosome-containing insoluble fractions from biofluids and culture media.
ExoSORT™ kit:
For Neural-Derived Exosomes (NDEs) SBH utilizes the ExoSORT™ kit developed and commercially available from NeuroDex.
We can develop and validate exosome purification kits for your specific projects. Please contact us with your specific needs or any questions related to Exosome services. We would be delighted to work with you.