Impact of chemically defined media conditions on the production and regenerative function of mesenchymal stem cell‐derived extracellular vesicles

Abstract

The use of mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have gained much attention because of their therapeutic potential for cardiac repair. However, their translation to the clinic is dependent on overcoming challenges, such as large-scale extracellular vesicle (EV) production. Although serum starvation is a widely used technique to increase EV production, it remains insufficient for large-scale production. On that note, a chemically defined medium for high density cell culture (CDM-HD) is believed to increase MSC-EV production in hollow fiber bioreactors; however, no comparative analysis has been performed between EVs from CDM-HD-cultured MSCs and starved MSCs in 2D cell culture systems. Therefore, this project aimed to assess the effects of culture conditions with CDM-HD on the production of human fetal MSC-EVs, and whether these EVs are functional. For the comparative analysis, EV yields from MSCs cultured in Opti-MEM or MEM-α with 10% CDM-HD supplementation or without (starvation) were determined using nanoparticle tracking analysis and western blot analysis. EV functionality was assessed using a scratch wound assay. The results showed that when compared to their starvation counterpart, Opti-MEM with CDM-HD (OM+CDM) resulted in the highest EV yield with a 9.6-fold increase within 24h, whereas within 48h, MEM-α with CDM-HD (M+CDM) increased EV yield with 17.2-fold. Regarding EV functionality, M+CDM EVs were able to induce endothelial cell migration; however, minor differences were observed with the procedural control. Taken together, culturing with CDM-HD increases EV yield to a greater extent than serum starvation. However, M+CDM EV functionality should be further explored to realize its potential as therapeutic agent for cardiac repair.