Mesenchymal stromal cell (MSC)-derived extracellular vesicles (MSC-EVs) are at the forefront of innovative therapies for inflammation and tissue regeneration. Our research proposes and deeply characterizes a workflow for large-scale production of high-quality EV doses using immortalized mesenchymal stromal cells (iMSC) in a hollow-fiber bioreactor (HFB).

We chose Wharton’s jelly-derived MSCs (WJ-MSC) for their superior proliferation and regenerative capabilities. By transfecting these cells with human telomerase reverse transcriptase (hTERT), we created stable, consistent iMSCs that meet the International Society for Cellular Therapy (ISCT) standards.

The HFB system offers significant benefits: prolonged cell culture without additional passages, minimized batch variability, and a supportive microenvironment. Importantly, we ensured the safety of our EVs with minimal transfer of the hTERT vector. Our comparative analyses showed that the HFB system produces higher yields of functional EVs than 2D cultures whole maintaining similar functional and phenotypical characteristics, including promoting angiogenesis. This innovative approach represents a major advancement in the cost-effective, large-scale production of MSC-EVs and sets a new benchmark, paving the way for clinical translation of MSC-EVs.