Examining the Synergic Effect of Exosomes Derived from Mouse Mesenchymal Stem Cells and Low-frequency Electromagnetic Field on Chondrogenic Differentiation

Background: Cartilage has intrinsically limited healing power, and regeneration of cartilage damages has remained a challenge. Secreted products of mesenchymal stem cells have shown a new therapeutic strategies for cartilage injuries. Also it has been observed that low frequency electromagnetic field plays a key role in biological processes. Objective: This research was performed to investigate the synergic effect of mesenchymal stem cell-derived exosomes and low frequency electromagnetic field on chondrogenic differentiation. Methods: In this in vitro study, mesenchymal stem cell-derived exosomes were identified using AFM, SEM, TEM microscopy, and DLS method. Cells were treated in chondrogenic medium by exosomes, low frequency electromagnetic field, and the synergy of both. The cell survival was examined using MTT and Annexin methods, and cartilage differentiation was confirmed by Alcian blue staining. The expression of Sox-9, Acan, Col 2a1 and Col 10a1 genes was examined via Real- Time PCR technique on day 14 post-treatment. Results: The results confirmed the presence of exosomes with an approximate size of less than 100 nm. The results of Alcian blue revealed greater expression of glycosaminoglycans in the synergic treatment group compared to the other groups. Real-time PCR showed a significant increase in the expression of Sox-9, Acan, and Col 2a1 genes, as well as a significant reduction of Col 10a1 gene expression in the synergic treatment group compared to other groups. Conclusion: This study indicated that the synergic effect of exosome and low-frequency electromagnetic fields would lead to enhanced chondrogenic differentiation, which can be further explored in future clinical studies