Introduction:Cartilages are inherently avascular and have limited repair capacity after injury. If not treated properly, these injuries can lead to progressive joint destruction and diseases such as osteoarthritis. Current treatment methods, including surgery and cartilage transplantation, face limitations such as inadequate access to healthy tissue, graft rejection, and poor-quality cartilage formation. Therefore, finding new strategies to stimulate efficient cartilage regeneration has become a critical need in regenerative medicine.In recent years, exosomes derived from mesenchymal stem cells (MSCs) have emerged as a promising tool in tissue regeneration. These extracellular vesicles contain growth factors, miRNAs, and proteins involved in tissue repair that can transmit therapeutic signals to target cells. Glucosamine, a naturally occurring amino monosaccharide, is an important precursor in the synthesis of glycosaminoglycans (GAGs) and proteoglycans, which are major components of the extracellular matrix of cartilage. This compound is widely used as a dietary supplement or drug in the treatment of degenerative joint diseases such as osteoarthritis. As a common supplement in the treatment of joint diseases, glucosamine plays an important role in stimulating the synthesis of cartilage extracellular matrix, promoting the differentiation of stem cells into chondrocytes, and inhibiting cartilage destruction.





Aims: The aim of this study was to investigate the combined effect of mouse bone marrow stem cell-derived exosomes and glucosamine on the expression of cartilage-specific genes including Sox9, Acan, Col2a1, and Col10a1.

Materials and methods: Bone marrow mesenchymal stem cells were prepared from NMRI mice. The mice were euthanized by cervical dislocation, the femoral heads were removed, and the bone marrow contents were transferred into a cell culture flask using a syringe containing culture medium. The bone marrow cells were cultured and were ready for use after 3 to 5 passages. The cell supernatant was separated, and exosomes were extracted from the cell supernatant by successive rounds of centrifugation followed by ultracentrifugation. Exosomes were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), and dynamic light scattering (DLS). The effects of exosomes and glucosamine on the expression of Sox9, Acan, Col2a1 and Col10a1 genes in mesenchymal stem cells were investigated in the presence of chondrogenic medium.

Results: The identification results from multiple characterization techniques confirmed the presence of exosomes with a size of approximately 100 nm. Real-time PCR results showed that the expression of Sox9, Acan and Col2a1 genes in stem cells treated with a combination of exosomes and glucosamine increased significantly compared to the other groups after 14 days of treatment, while the expression of the Col10a1 gene decreased significantly compared to the other groups.

Conclusion: This study demonstrated that the combination of exosomes derived from bone marrow mesenchymal stem cells and glucosamine can synergistically increase the expression of key genes in chondrogenic differentiation (Sox9, Acan and Col2a1) while reducing the expression of the Col10a1 gene (related to chondrocyte hypertrophy). These findings suggest the therapeutic potential of this combination in stimulating cartilage regeneration and preventing further degradation. Given these promising results, this approach should be further investigated in clinical studies as a novel therapeutic strategy for cartilage damage.