Effect comparison of stem cell-derived exosomes on angiogenesis and osteogenesis obtained by ultracentrifugation versus size-exclusion chromatography
Objective:To compare the yield,purity,bioactivity,and bone repair potential of stem cell-derived exosomes isolated using ultracentrifugation and size-exclusion chromatography.Methods:Exosomes were isolated from the supernatant of bone marrow mesenchymal stem cells via ultracentrifugation and size-exclusion chromatography.The exosomes were characterized by evaluating their particle size,morphology,and marker proteins.The protein content in the exosomes was quantified via a bicinchoninic acid(BCA)method,and angiogenesis-related proteins were analyzed via an angiogenesis factor array kit.In vitro angiogenic potential was assessed through scratch and tube formation assays.Additionally,the ability of exosomes to promote bone repair and regeneration was evaluated in a rat bone defect model.Results:The mass of exosomes obtained via ultracentrifugation(Exo-UC)per volume of supernatant was lower than those obtained via size-exclusion chromatography(Exo-SEC).Transmission electron microscopy revealed fewer impurity proteins in Exo-SEC than in Exo-UC.Exo-UC contained 16 angiogenic proteins,whereas Exo-SEC contained fewer angiogenic proteins in terms of both species and content.Compared with Exo-SEC,Exo-UC significantly enhanced endothelial cell migration and tube formation.Furthermore,Exo-UC significantly increased the bone volume percentage and bone mineral density at bone defect sites in rats.Conclusions:Exosomes extracted from stem cells via ultracentrifugation demonstrate enhanced angiogenic potential and superior bone repair efficacy.