LAUSR

Mesenchymal stromal cells (MSC) have recently been explored for their potential use as therapeutics in human and veterinary medicine applications, such as the treatment of endometrial inflammation and infertility. Allogeneic MSC-derived extracellular vesicles (EVs) may also provide therapeutic benefits with advantage of being an "off-the-shelf" solution, provided they can be produced in large enough quantities, without contamination from bovine EVs contained in fetal bovine serum that is a common component of cell culture media. Towards this aim, we demonstrated the successful isolation and characterisation of equine MSCs from pre-implantation embryos. We also demonstrate that many of these lines can be propagated long-term in culture while retaining their differentiation potential, and conducted a head-to-head comparison of two bioreactor systems for scalable EV production including in serum-free conditions. Based on our findings, the CELLineTM AD 1000 flasks enabled higher cell density cultures and significantly more EV production than the FiberCellTM system or conventional culture flasks. These findings will enable future isolation of equine MSCs and the scalable culture of their EVs for a wide range of applications in this rapidly growing field.