Exosome potency assays

EVerZom offers customized services for potency assays developments and internalization assays. EverZom has developed and standardized two assays to evaluate the immunomodulatory and angiogenesis properties of exosomes.

Exosome immunomodulation assay

EVerZom provides an exosome potency assay to evaluate their immunomodulatory potential. The global trend of an EV batch on inflammation is obtained through the study of either NF-κB pathway or IRF pathway. This is done by using THP-1 dual cell lines, derived from human THP-1 monocyte cell line by stable integration of two inducible reporter constructs. THP-1 dual cells are seeded into a 96-well plate. EVs ± LPS (for THP-1 activation), LPS (positive control) and Dex (Dexamethasone, negative control) are added right after, for 24h. After incubation, samples are recovered for immunomodulation assay. It evaluates the anti-inflammatory effect of EVs on LPS-activated THP-1 dual cells (in red), but also to monitor the inflammatory effect by adding EVs alone (in green). It is also possible to dose specific cytokines by an ELISA.

Figure 1: Immunomodulatory potential of EVs through the NF-ÎşB pathway activation (left), and release of TNF-a (right).

Exosome angiogenesis assay

Scratch tests are potency assays used to analyse the cell regenerative capacity of extracellular vesicles (EVs). At EVerZom, we use HUVEC (human umbilical vein endothelial cells) that also give an information on the angiogenesis capacity of EVs.

HUVEC are seeded in a microwell plate for 24h. Then, a scratch is made at the bottom of each well, the cells are washed, and the different conditions are initiated: the medium without growth factors and serum for negative control, and with for positive control. EVs are tested at different concentrations to establish if they activate or inhibit the growth in a dose-response manner. The cell regeneration/migration is tracked during ~72h with a picture captured every hour by an EVOS M7000.

Images and videos are analysed by a proprietary algorithm to quantify the healing speed.

In addition to exosome potency assays, EVerZom provides exosome biochemical characterization and exosome size measurement services.