Sodium Alginate Hydrogels Loaded with Mesenchymal Stem Cells-Derived Extracellular Vesicles: Safety and Cell...

Wound healing is a complex process often impaired in severe injuries, requiring innovative therapeutic strategies. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) modulate key cellular pathways, but their clinical application is limited by low stability and bioavailability. This study aimed to evaluate the safety and potential of sodium alginate hydrogels (SAH-EVs) loaded with mesenchymal stem cell-derived extracellular vesicles, focusing on cell migration, cytotoxicity, genotoxicity, and irritation potential. MSC-EVs from Sprague-Dawley rat bone marrow were isolated from conditioned medium collected at 24, 36, 48 and 60 h using size exclusion chromatography and characterized by Nanoparticle Tracking Analysis. The highest EV concentration was obtained from the conditioned medium collected at 36 h, with a main peak at 123 nm. The heterogeneous particle population suggests the presence of EV subtypes. Scanning Electron Microscopy confirmed successful MSC-EVs incorporation into hydrogels with desirable viscoelastic properties. SAH-EVs stimulated HaCaT keratinocyte migration while exhibiting low cytotoxicity in 2D and 3D models, with no genotoxic or mutagenic effects. HET-CAM assays confirmed the absence of irritation potential. These findings highlight the potential of SAH-EVs as a safe biomaterial and lay the groundwork for further investigations into their role in wound healing, reinforcing their relevance in regenerative medicine and tissue engineering.