Comprehensive Comparison of Extracellular Vesicles Derived from Mesenchymal Stem Cells Cultured with Fetal Bovine Serum and Human Platelet Lysate

Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have emerged as a promising approach in regenerative therapy. However, the clinical application of MSC-EVs is hindered by the presence of xenogenic components, such as fetal bovine serum (FBS), which is the most used culture supplement for MSCs. Human platelet lysate (HPL) has been proposed as an alternative to FBS, but whether MSC-EVs derived from HPL-cultured MSCs are suitable for clinical translation remains unclear. In this study, we comprehensively compared the characterization of EVs derived from MSCs cultured in the medium with FBS (F-EVs) and HPL (H-EVs). Our study showed that HPL promoted MSC-EV production without compromising EVs critical quality attributes. Multiomics sequencing revealed the stability of H-EVs from different umbilical cord donors and global functional alterations for MSC-EVs under different culture conditions. In comparison to F-EVs, H-EVs enriched more angiogenesis-related molecules and exhibited enhanced angiogenesis, which were further confirmed by <i>in vivo</i> and <i>in vitro</i> studies. H-EVs significantly reduced renal microvascular rarefaction and promoted the regeneration of umbilical vein endothelial cells to hypoxia stimulation compared to that of F-EVs. In conclusion, our findings demonstrated that HPL as culture supplements did not alter the critical quality attributes of MSC-EVs, specifically holding a higher yield and quality of MSC-EVs with enhanced angiogenic potential.