Developing a three-dimensional culture system to improve the yield of placental mesenchymal stem cell derived extracellular vesicles

Placental mesenchymal stem cell (PMSC) derived extracellular vesicles (PMSC-EVs) are lipid-bound vesicles secreted from the cell through different biogenic pathways including membrane blebbing, budding, and endocytosis and exocytosis pathways. PMSC-EVs function through intercellular communication by distribution of their biologically functional cargo including DNA, RNA and proteins. This biologically functional material can trigger a multitude of physiological responses such as cellular regeneration and tissue damage response. They have also been shown to have less toxicity and immunogenicity, ability to encapsulate biologically active molecules, and ability to cross the blood brain barrier when compared to cell-based therapies. However, the current applications of PMSC-EVs is limited by their low yield when produced in conventional monolayer cell culture. The CELLine bioreactor, which can allow for a high-density three-dimensional (3D) cell culture within a semipermeable membrane, has been utilized as a large scale tissue culture method for producing antibodies as well as for use in cancer EV related research. In this study, we propose to explore the application of the CELLine bioreactor as a novel approach to improve the production and yield of PMSC-EVs for regenerative medicine applications.