Effect of Mechanical Environment Alterations in 3D Stem Cell Culture on the Therapeutic Potential of Extracellular Vesicles.

Stem-cell-derived extracellular vesicles (EVs) have emerged as a promising therapeutic option, addressing the limitations of conventional stem cell therapies. However, the variability and poorly defined therapeutic contents of EVs produced under standard 2-dimensional culture conditions present challenges for their clinical application. In this study, we investigated how the therapeutic properties of mesenchymal stem cell (MSC)-derived EVs can be enhanced by culturing MSCs within 3-dimensional hydrogels that have tunable mechanical properties. Our results demonstrate that different mechanical cues from the culture environment can induce specific gene expression changes in MSCs without compromising their inherent characteristics. Furthermore, EVs derived from these MSCs exhibited distinct angiogenic and immunomodulatory activities, which were dependent on the mechanical properties of the hydrogels used. A comprehensive analysis of the cytokines and microRNAs present in the EVs provided additional validation of these findings. By utilizing a noninvasive culture method that eliminates the need for genetic modification or exogenous biochemical supplementation, our approach presents a novel platform for the tailored production of EVs, thereby enhancing their therapeutic potential in regenerative medicine.