Increased potency of human placental mesenchymal stromal cell-derived extracellular vesicles from scaled-up hollow fiber bioreactor production

ABSTRACT Mesenchymal stromal cells (MSCs), and more recently MSC-derived extracellular vesicles (MSC-EVs), have demonstrated translational potential, with the first MSC therapy approved by the FDA in 2024 and multiple clinical trials evaluating MSC-EVs. However, clinical translation of MSC-EVs remains limited by batch-to-batch variability in EV properties. To investigate how culture systems affect EV properties and evaluate early gestation placenta-derived MSCs (PMSCs), PMSCs were cultured in tissue culture flasks or a hollow fiber bioreactor and comparatively assessed for cellular and EV composition and potency. Bioreactor-cultured PMSCs exhibited increased neuroprotective and wound-healing potency while maintaining MSC markers, differentiation potential, and a normal karyotype. Proteomic analysis revealed distinct EV profiles between culture conditions, with bioreactor-derived PMSC-EVs enriched in proteins including neuraminidase 1, dynamin-related protein 1, and matrix metalloproteinases involved in tissue remodeling, apoptosis regulation, and immune modulation. Across independent PMSC donor lines, bioreactor culture consistently enhanced functional efficacy. These findings demonstrate that culture conditions substantially influence PMSC and EV properties and highlight the therapeutic potential of PMSC-EVs for translational development.