Impact of Stimulation Parameters and 3D Hydrogel Degradability on the Immunomodulatory Function of Encapsulated Human Mesenchymal Stromal Cells

Mesenchymal stromal cells (MSCs) have emerged as promising therapeutics for immune diseases due to their modulation of immune cells. Their therapeutic effects are mediated through the secretion of immunomodulatory factors packaged in extracellular vesicles (EVs). Control of MSC growth and EV production are critical components of EV therapeutic development, but there is limited understanding of how different aspects of the manufacturing process impact EV reproducibility and production. Studies have shown the effectiveness of traditional methods including 2D flask "stacks" and bioreactors for large-scale production of MSCs and EVs. However, these methods lack precise control over the microenvironment. 3D hydrogels emerge as a promising alternative due to their ease of modification and their capacity to better mimic the physiological conditions inside the human body. Since hydrogels are fabricated from modified polymers, their biomechanical properties are easy to tune, enabling versatility in the resultant cellular responses. Specifically, this study investigates the influence of the 3D hydrogel microenvironment and different stimulation parameters on MSC-EV immunomodulatory function.